Merge pull request #15015 from Mik00000/perf/async-chunk-save

perf(anvil): offload chunk compression during region flush to worker pool
Merge pull request #16149 from rdbtCVS/t3/spawn-lanes
2026-11-13 17:35:33 -10:00 · 2026-11-13 22:49:59 +00:00 · 2026-11-13 22:02:56 +00:00 · 2026-11-13 21:41:11 +00:00 · 2026-11-13 21:40:29 +00:00 · 2026-11-13 21:36:49 +00:00
1149 changed files with 84175 additions and 12486 deletions
@@ -0,0 +1,4 @@
+# `cargo xtask …` runs the repository's task crate, so the commands in docs/perf-platform.md and
+# web/perf/README.md work as written. `cargo run -p xtask -- …` stays equivalent.
+[alias]
+xtask = "run --package xtask --"
@@ -2,8 +2,9 @@

 ## What and why

-<!-- What this changes, and why. Link the issue it fixes ("Fixes #123"). Over about 500 lines: link the issue with its
-     approved spec too ("Spec: #123"), CONTRIBUTING.md "Large pull requests". -->
+<!-- What this changes, and why. Link the issue it fixes ("Fixes #123"). Over about 500 lines of code
+     (docs and test files don't count): link the issue with its approved spec too ("Spec: #123"), CONTRIBUTING.md
+     "Large pull requests". -->

 ## Kind

@@ -0,0 +1,56 @@
+name: perf-wasm
+# The site consumes this reader bundle from horizon-rust/horizon-site.
+on:
+  push:
+    branches: [main]
+    paths:
+      - 'crates/horizon-perf/**'
+      - 'crates/horizon-perf-format/**'
+      - 'crates/horizon-bench/**'
+      - 'xtask/**'
+      - 'Cargo.lock'
+      - 'Cargo.toml'
+      - '.github/workflows/perf-wasm.yml'
+  pull_request:
+    types: [opened, synchronize, reopened]
+    paths:
+      - 'crates/horizon-perf/**'
+      - 'crates/horizon-perf-format/**'
+      - 'crates/horizon-bench/**'
+      - 'xtask/**'
+      - 'Cargo.lock'
+      - 'Cargo.toml'
+      - '.github/workflows/perf-wasm.yml'
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: perf-wasm-${{ github.event.pull_request.number || github.sha }}
+  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+    env:
+      HORIZON_TELEMETRY_URL: "off"
+    steps:
+      - uses: actions/checkout@v7
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          targets: wasm32-unknown-unknown
+      - uses: Swatinem/rust-cache@v2
+        with:
+          key: perf-wasm
+      # The agreement test: the C ABI, called natively, must print the bytes the CLI prints.
+      - name: The wasm ABI agrees with the CLI
+        run: cargo test -p horizon-perf --features wasm --test wasm
+      - name: Build the wasm the page loads
+        run: cargo run -p xtask -- perf-wasm
+      - uses: actions/upload-artifact@v4
+        with:
+          name: perf-wasm
+          path: target/perf-wasm
+          if-no-files-found: error
@@ -34,8 +34,9 @@ Feature → files → harness for the most-changed areas: [docs/architecture.md]
 - Everything players run is Rust. Python/Java only for dev tools and harness drivers in `tools/`.
 - Horizon-only features follow [docs/design-system.md](docs/design-system.md) and are off by default where
  they would change the vanilla look.
- Small PRs (< ~500 lines). Labels: `feature` (players get something new), `skip-release` (they see no
-  change), none for a fix. Agents never add `release-now`: the maintainer decides it. Merges ship in batches of 5, or after
+- Small PRs (< ~500 lines of code; docs and test files don't count:
+  [CONTRIBUTING.md](CONTRIBUTING.md#pull-requests)). Labels: `feature` (players get something new), `skip-release`
+  (they see no change), none for a fix. Agents never add `release-now`: the maintainer decides it. Merges ship in batches of 5, or after
  6 hours ([docs/release-flow.md](docs/release-flow.md)).
 - **No hardcoded user-facing strings.** Keep UI translation-ready from the start. In the launcher (`launcher/`), wrap visible text with `tr("...")` or `trf("... {arg} ...", &[("arg", &val)])` from `crate::i18n` instead of raw string literals or `format!`. In the game, use translation keys (`Text::tr`, `lang::get`), never hardcoded English strings.
 - **Claim before you start**: comment `/claim` on the issue (no issue yet: open one, then claim it). An assigned
@@ -102,6 +103,7 @@ Game workspace (root `Cargo.toml`); `launcher/` and `crates/horizon-telemetry-se
 | `horizon-shader-api` | Horizon's own WGSL shader packs ([docs/api/shaders.md](docs/api/shaders.md)): `horizon-shaders.toml`, the `.hshader` package; shared by the game, the launcher and the registry |
 | `horizon-shaders` | Shader packs (the `shaders/` folder format), rebuilt clean-room from a written spec of the format; no wgpu |
 | `horizon-theme` | Design tokens and fonts for the launcher, the game's own menus and the website |
+| `horizon-perf-format` | The `.hzperf` capture contract ([docs/perf-platform.md](docs/perf-platform.md) §3): `proto/horizon/perf/v1/capture.proto`, its generated types, the gzip writer and its thread. No Horizon dependencies; nothing in the game reads a capture |
 | `horizon-telemetry`, `horizon-telemetry-server`, `horizon-bench` | Opt-in data collection, its ingest server, the benchmark report format |
 | `horizon-system` | The machine the game runs on (OS, CPU, memory, drive, power, GPU maker and memory), for the crash report, the renderer's GPU info and telemetry |
 | `horizon-platform` | The platform's public API: what the Horizon layer may use of the engine ([docs/layers.md](docs/layers.md)); re-exports `horizon-system` today |
@@ -213,7 +215,7 @@ state stays separate from the library tests. This compiles gameplay twice for ex
 | Resource packs | L: `packs.rs` + `packs/`, `pack_screen.rs`, `atlas_sources.rs`, `sprites.rs`, `mipmap.rs`, `model_library.rs`, `font.rs`, `mobs/cem.rs` + `mobs/cem_anim.rs` (OptiFine/EMF entity models and their animations); `horizon-client-core/src/lang.rs`; crates `horizon-assets`, `horizon-optifine`; G: `packs.rs` |
 | Agent control | L: `control.rs` (socket), `bin/horizon-ctl/`; G: `control.rs`, `agent.rs`, `events.rs`, `ui_control.rs` ([docs/agent-control.md](docs/agent-control.md)) |
 | Mods | crate `horizon-mods`; G: `mods.rs`; L: `mod_content.rs`, `mod_list.rs` |
-| Horizon extras, settings | L: `extras.rs`, `graphics.rs`, `settings.rs`, `minimap.rs`; G: `extras.rs`, `tweaks.rs`, `options.rs` |
+| Horizon extras, settings | L: `extras.rs`, `graphics.rs`, `settings.rs`, `minimap.rs`; G: `extras.rs` + `extras/` (each extra's glue: `mouse_tweaks.rs`, `sorting.rs`, `pvp.rs`, `reconnect.rs`), `options.rs` |

 ## How `Game` is organised

@@ -144,7 +144,9 @@ it (edited on every push, never repeated): talk to its author in the thread befo

 - **Small.** One change per pull request, under about 500 lines of code where you can; split bigger work into
  pieces that each make sense alone. Small pull requests get reviewed and merged the same day. Bigger than that:
-  [large pull requests](#large-pull-requests).
+  [large pull requests](#large-pull-requests). What counts: lines added plus lines removed, outside Markdown (`.md`)
+  files and test files (any `tests/` or `test/` folder, and `test_*.py`). Tests written inside a source file do count.
+  pr_ready counts it the same way and warns when a pull request is over.
 - **Fill in the template**: what and why, the vanilla reference, the pr_ready block, screenshots for anything you
  can see.
 - **Tick "Allow edits by maintainers".** When something small is left (a lint, a rebase, a nit) we push the fixup
@@ -169,7 +171,8 @@ How agents, checks, releases and signed updates keep this safe: [security](docs/

 ### Large pull requests

-500 lines stays the default. A pull request that can't be split below it starts from a spec:
+500 lines of code ([what counts](#pull-requests)) stays the default. A pull request that can't be split below it
+starts from a spec:

 1. **Open an issue with the spec** before the code: what changes, the files it touches, the behaviour players and
   other code will see, and the tests or harnesses that prove it.
@@ -18,6 +18,15 @@ version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "366ffbaa4442f4684d91e2cd7c5ea7c4ed8add41959a31447066e279e432b618"

+[[package]]
+name = "addr2line"
+version = "0.26.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "59317f77929f0e679d39364702289274de2f0f0b22cbf50b2b8cff2169a0b27a"
+dependencies = [
+ "gimli",
+]
+
 [[package]]
 name = "adler2"
 version = "2.0.1"
@@ -129,6 +138,12 @@ dependencies = [
 "libc",
 ]

+[[package]]
+name = "anyhow"
+version = "1.0.104"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "330a5ed07fa54e4702c9d6c4174f74427fc0ef6e214bbd677ae50a5099946470"
+
 [[package]]
 name = "arboard"
 version = "3.7.0"
@@ -264,6 +279,12 @@ version = "1.8.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2af50177e190e07a26ab74f8b1efbfe2ef87da2116221318cb1c2e82baf7de06"

+[[package]]
+name = "beef"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3a8241f3ebb85c056b509d4327ad0358fbbba6ffb340bf388f26350aeda225b1"
+
 [[package]]
 name = "bit-set"
 version = "0.10.0"
@@ -559,7 +580,7 @@ checksum = "af491d569909a7e4dee0ad7db7f5341fef5c614d5b8ec8cf765732aba3cff681"
 dependencies = [
 "serde",
 "termcolor",
- "unicode-width",
+ "unicode-width 0.2.2",
 ]

 [[package]]
@@ -1011,6 +1032,12 @@ version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7360491ce676a36bf9bb3c56c1aa791658183a54d2744120f27285738d90465a"

+[[package]]
+name = "fastrand"
+version = "2.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "da7c62ceae207dd37ea5b845da6a0696c799f85e97da1ab5b7910be3c1c80223"
+
 [[package]]
 name = "fdeflate"
 version = "0.3.7"
@@ -1109,6 +1136,18 @@ dependencies = [
 "percent-encoding",
 ]

+[[package]]
+name = "framehop"
+version = "0.16.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6f54fe4785e899d4d6f43793b151c63c5647240fc630b005509d2614a939f693"
+dependencies = [
+ "arrayvec",
+ "cfg-if",
+ "fallible-iterator",
+ "gimli",
+]
+
 [[package]]
 name = "fs4"
 version = "1.1.0"
@@ -1246,6 +1285,15 @@ dependencies = [
 "windows 0.62.2",
 ]

+[[package]]
+name = "gimli"
+version = "0.33.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0bf7f043f89559805f8c7cacc432749b2fa0d0a0a9ee46ce47164ed5ba7f126c"
+dependencies = [
+ "stable_deref_trait",
+]
+
 [[package]]
 name = "gl_generator"
 version = "0.14.0"
@@ -1426,7 +1474,7 @@ dependencies = [
 name = "horizon-bench"
 version = "0.1.0"
 dependencies = [
- "horizon-telemetry",
+ "horizon-system",
 "serde",
 "serde_json",
 ]
@@ -1457,7 +1505,6 @@ dependencies = [
 "bytemuck",
 "chrono",
 "crc32fast",
- "dunce",
 "flate2",
 "fs4",
 "gilrs",
@@ -1482,10 +1529,13 @@ dependencies = [
 "horizon-mods",
 "horizon-narrator",
 "horizon-optifine",
+ "horizon-perf",
+ "horizon-perf-format",
 "horizon-protocol",
 "horizon-server-files",
 "horizon-shader-api",
 "horizon-shaders",
+ "horizon-system",
 "horizon-telemetry",
 "horizon-theme",
 "horizon-threads",
@@ -1496,7 +1546,6 @@ dependencies = [
 "objc2 0.6.5",
 "objc2-app-kit 0.3.2",
 "objc2-foundation 0.3.2",
- "open",
 "png",
 "pollster",
 "rustix 1.1.5",
@@ -1540,6 +1589,7 @@ dependencies = [
 "bytemuck",
 "chrono",
 "crc32fast",
+ "dunce",
 "flate2",
 "fs4",
 "getrandom 0.3.4",
@@ -1560,6 +1610,8 @@ dependencies = [
 "horizon-mods",
 "horizon-narrator",
 "horizon-optifine",
+ "horizon-perf",
+ "horizon-perf-format",
 "horizon-protocol",
 "horizon-server-files",
 "horizon-shader-api",
@@ -1614,6 +1666,8 @@ dependencies = [
 "horizon-items",
 "horizon-narrator",
 "horizon-optifine",
+ "horizon-perf",
+ "horizon-perf-format",
 "horizon-polytone",
 "horizon-protocol",
 "horizon-shader-api",
@@ -1831,6 +1885,7 @@ dependencies = [
 "horizon-game",
 "horizon-heartbeat",
 "horizon-official-servers",
+ "horizon-perf-share",
 "horizon-platform",
 "log",
 "winresource",
@@ -1849,18 +1904,60 @@ dependencies = [
 name = "horizon-optifine"
 version = "0.1.0"
 dependencies = [
- "horizon-bench",
 "horizon-core",
+ "horizon-system",
 "log",
 "regex",
 ]

+[[package]]
+name = "horizon-perf"
+version = "0.1.0"
+dependencies = [
+ "flate2",
+ "horizon-bench",
+ "horizon-perf-format",
+ "horizon-perf-share",
+ "prost",
+ "regex",
+ "serde",
+ "serde_json",
+]
+
+[[package]]
+name = "horizon-perf-format"
+version = "0.1.0"
+dependencies = [
+ "flate2",
+ "prost",
+ "prost-build",
+ "prost-types",
+ "protox",
+]
+
+[[package]]
+name = "horizon-perf-share"
+version = "0.1.0"
+dependencies = [
+ "getrandom 0.3.4",
+ "horizon-addresses",
+ "horizon-platform",
+ "log",
+ "open",
+ "serde",
+ "serde_json",
+ "ureq",
+ "url",
+]
+
 [[package]]
 name = "horizon-platform"
 version = "0.1.0"
 dependencies = [
+ "horizon-bench",
 "horizon-core",
 "horizon-hooks",
+ "horizon-perf-format",
 "horizon-prepare",
 "horizon-protocol",
 "horizon-server-files",
@@ -1945,7 +2042,6 @@ dependencies = [
 "chrono",
 "getrandom 0.3.4",
 "horizon-anticheat",
- "horizon-bench",
 "horizon-chat-filter",
 "horizon-mcp",
 "horizon-platform",
@@ -2029,9 +2125,14 @@ version = "0.1.0"
 name = "horizon-threads"
 version = "0.1.0"
 dependencies = [
+ "addr2line",
+ "framehop",
 "libc",
 "libmimalloc-sys",
+ "memmap2",
 "mimalloc",
+ "object",
+ "rustc-demangle",
 "windows-sys 0.61.2",
 ]

@@ -2041,6 +2142,7 @@ version = "0.1.0"
 dependencies = [
 "flate2",
 "horizon-core",
+ "horizon-threads",
 "libm",
 "log",
 "lz4_flex",
@@ -2282,6 +2384,15 @@ dependencies = [
 "once_cell",
 ]

+[[package]]
+name = "itertools"
+version = "0.14.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b192c782037fadd9cfa75548310488aabdbf3d2da73885b31bd0abd03351285"
+dependencies = [
+ "either",
+]
+
 [[package]]
 name = "itoa"
 version = "1.0.18"
@@ -2508,6 +2619,72 @@ version = "0.4.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f9f8bd3e56ce4dfc153cf470fffbfa98c7620958b312ca5c3a4b8d5181fd13c6"

+[[package]]
+name = "logos"
+version = "0.15.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ff472f899b4ec2d99161c51f60ff7075eeb3097069a36050d8037a6325eb8154"
+dependencies = [
+ "logos-derive 0.15.1",
+]
+
+[[package]]
+name = "logos"
+version = "0.16.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eb2c55a318a87600ea870ff8c2012148b44bf18b74fad48d0f835c38c7d07c5f"
+dependencies = [
+ "logos-derive 0.16.1",
+]
+
+[[package]]
+name = "logos-codegen"
+version = "0.15.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "192a3a2b90b0c05b27a0b2c43eecdb7c415e29243acc3f89cc8247a5b693045c"
+dependencies = [
+ "beef",
+ "fnv",
+ "lazy_static",
+ "proc-macro2",
+ "quote",
+ "regex-syntax",
+ "rustc_version",
+ "syn 2.0.119",
+]
+
+[[package]]
+name = "logos-codegen"
+version = "0.16.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "58b3ffaa284e1350d017a57d04ada118c4583cf260c8fb01e0fe28a2e9cf8970"
+dependencies = [
+ "fnv",
+ "proc-macro2",
+ "quote",
+ "regex-automata",
+ "regex-syntax",
+ "syn 2.0.119",
+]
+
+[[package]]
+name = "logos-derive"
+version = "0.15.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "605d9697bcd5ef3a42d38efc51541aa3d6a4a25f7ab6d1ed0da5ac632a26b470"
+dependencies = [
+ "logos-codegen 0.15.1",
+]
+
+[[package]]
+name = "logos-derive"
+version = "0.16.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "52d3a9855747c17eaf4383823f135220716ab49bea5fbea7dd42cc9a92f8aa31"
+dependencies = [
+ "logos-codegen 0.16.1",
+]
+
 [[package]]
 name = "lru"
 version = "0.18.5"
@@ -2550,6 +2727,28 @@ dependencies = [
 "libc",
 ]

+[[package]]
+name = "miette"
+version = "7.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5f98efec8807c63c752b5bd61f862c165c115b0a35685bdcfd9238c7aeb592b7"
+dependencies = [
+ "cfg-if",
+ "miette-derive",
+ "unicode-width 0.1.14",
+]
+
+[[package]]
+name = "miette-derive"
+version = "7.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "db5b29714e950dbb20d5e6f74f9dcec4edbcc1067bb7f8ed198c097b8c1a818b"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.119",
+]
+
 [[package]]
 name = "mimalloc"
 version = "0.1.52"
@@ -2603,6 +2802,12 @@ dependencies = [
 "windows-sys 0.61.2",
 ]

+[[package]]
+name = "multimap"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1d87ecb2933e8aeadb3e3a02b828fed80a7528047e68b4f424523a0981a3a084"
+
 [[package]]
 name = "multiversion_no_op"
 version = "1.0.0"
@@ -3183,6 +3388,15 @@ dependencies = [
 "objc2-foundation 0.2.2",
 ]

+[[package]]
+name = "object"
+version = "0.39.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2e5a6c098c7a3b6547378093f5cc30bc54fd361ce711e05293a5cc589562739b"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "oid-registry"
 version = "0.8.1"
@@ -3514,6 +3728,16 @@ version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e8cf8e6a8aa66ce33f63993ffc4ea4271eb5b0530a9002db8455ea6050c77bfa"

+[[package]]
+name = "prettyplease"
+version = "0.2.37"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "479ca8adacdd7ce8f1fb39ce9ecccbfe93a3f1344b3d0d97f20bc0196208f62b"
+dependencies = [
+ "proc-macro2",
+ "syn 2.0.119",
+]
+
 [[package]]
 name = "proc-macro-crate"
 version = "3.5.0"
@@ -3538,6 +3762,96 @@ version = "1.0.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3d595e54a326bc53c1c197b32d295e14b169e3cfeaa8dc82b529f947fba6bcf5"

+[[package]]
+name = "prost"
+version = "0.14.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "528ac67416ff8646872a3c02cad9cc4ee5dc9f9540c9b10771855c95cb2e5ae1"
+dependencies = [
+ "bytes",
+ "prost-derive",
+]
+
+[[package]]
+name = "prost-build"
+version = "0.14.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "03da047801ff44bb6a4d407d4860c05fd70bb81714e6b2f3812603d5b145b042"
+dependencies = [
+ "heck",
+ "itertools",
+ "log",
+ "multimap",
+ "petgraph",
+ "prettyplease",
+ "prost",
+ "prost-types",
+ "regex",
+ "syn 2.0.119",
+ "tempfile",
+]
+
+[[package]]
+name = "prost-derive"
+version = "0.14.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b570b25f7617e43d59005d0990ccb79e950a423952cea19671b7a876da390adf"
+dependencies = [
+ "anyhow",
+ "itertools",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.119",
+]
+
+[[package]]
+name = "prost-reflect"
+version = "0.16.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "01b80ea363c31af2de2b92e3c07ed1156628f7838c4afb4df75ee78a37fedbd1"
+dependencies = [
+ "logos 0.16.1",
+ "miette",
+ "prost",
+ "prost-types",
+]
+
+[[package]]
+name = "prost-types"
+version = "0.14.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f94967dc7688f3054c7fac87473ffae4cc4c3904800e2d9f5b857246d8963b0a"
+dependencies = [
+ "prost",
+]
+
+[[package]]
+name = "protox"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4f25a07a73c6717f0b9bbbd685918f5df9815f7efba450b83d9c9dea41f0e3a1"
+dependencies = [
+ "bytes",
+ "miette",
+ "prost",
+ "prost-reflect",
+ "prost-types",
+ "protox-parse",
+ "thiserror 2.0.21",
+]
+
+[[package]]
+name = "protox-parse"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "072eee358134396a4643dff81cfff1c255c9fbd3fb296be14bdb6a26f9156366"
+dependencies = [
+ "logos 0.15.1",
+ "miette",
+ "prost-types",
+ "thiserror 2.0.21",
+]
+
 [[package]]
 name = "quick-error"
 version = "2.0.1"
@@ -3837,6 +4151,12 @@ dependencies = [
 "smallvec",
 ]

+[[package]]
+name = "rustc-demangle"
+version = "0.1.28"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b74b56ffa8bb2830709a538c2cbcae9aa062db0d2a42563bfb09bdaae44020eb"
+
 [[package]]
 name = "rustc-hash"
 version = "1.1.0"
@@ -4395,6 +4715,18 @@ dependencies = [
 "syn 3.0.6",
 ]

+[[package]]
+name = "tempfile"
+version = "3.27.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "32497e9a4c7b38532efcdebeef879707aa9f794296a4f0244f6f69e9bc8574bd"
+dependencies = [
+ "fastrand",
+ "once_cell",
+ "rustix 1.1.5",
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "termcolor"
 version = "1.4.1"
@@ -4664,6 +4996,12 @@ version = "1.13.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c6f5d3c3b1bf09027a88a6bc961fc00497d651009560b5463668dc81b0fa87a8"

+[[package]]
+name = "unicode-width"
+version = "0.1.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7dd6e30e90baa6f72411720665d41d89b9a3d039dc45b8faea1ddd07f617f6af"
+
 [[package]]
 name = "unicode-width"
 version = "0.2.2"
@@ -37,6 +37,9 @@ members = [
    "crates/horizon-discord",
    "crates/horizon-official-servers",
    "crates/horizon-bench",
+    "crates/horizon-perf-format",
+    "crates/horizon-perf",
+    "crates/horizon-perf-share",
    "crates/horizon-friends",
    "crates/horizon-relay",
    "crates/horizon-mods",
@@ -62,6 +62,8 @@ The GLSL frontend also resets the common type for each comma-separated declarato
 variable's array specifier does not change later variables.
 It also reads a struct member outside a constant expression through a pointer to the member,
 not out of a loaded copy of the whole struct, so a member an atomic function uses can be read.
+The shared interpolation defaults also compile with `glsl-in` alone, without needing the
+SPIR-V or WGSL frontend to enable them.

 ## DirectX Shader Compiler

@@ -356,6 +358,9 @@ Horizon (Copyright (c) 2026 Ludovic Marie and the Horizon contributors).
 `crates/horizon-client-render/src/touch.rs` and `touch/tests/` are adapted from the touch input
 state of Starling's `crates/horizon-client-render/src/touch.rs` at the same commit.

+`crates/horizon-client-render/src/touch/draw.rs` is adapted from the touch control drawing in
+Starling's `crates/horizon-client-render/src/touch.rs` at the same commit.
+
 `crates/horizon-client-render/src/android_runtime.rs` and `android_runtime/tests/` are adapted from the
 input part of Starling's `crates/horizon-client-render/src/android_runtime.rs` at the same commit.

@@ -35,6 +35,12 @@ pub const COSMETICS_API: &str = "https://cosmetics.playhorizon.dev";
 /// "I'm playing" ping, benchmark uploads (`HORIZON_TELEMETRY_URL` overrides it).
 pub const TELEMETRY: &str = "https://telemetry.playhorizon.dev";

+/// The performance viewer page a saved capture opens in (`HORIZON_PERF_VIEWER` overrides it).
+pub const PERF_VIEWER: &str = "https://playhorizon.dev/perf";
+
+/// The capture upload API behind Share (`HORIZON_PERF_CAPTURES` overrides it).
+pub const PERF_CAPTURES: &str = "https://playhorizon.dev/api/perf/captures";
+
 /// Public STUN servers for Play with Friends' NAT discovery: two independent operators, so one
 /// outage doesn't break discovery (`HORIZON_STUN_SERVERS` overrides them).
 pub const STUN_SERVERS: &[&str] = &["stun.cloudflare.com:3478", "stun.l.google.com:19302"];
@@ -206,7 +206,7 @@ impl Config {
        Ok(file.anticheat)
    }

-    /// Thresholds can't be negative.
+    /// Thresholds can't be negative, and neither can the timer's milliseconds.
    pub fn check(&self) -> Result<(), String> {
        for &c in Check::ALL {
            let a = self.actions(c);
@@ -220,6 +220,18 @@ impl Config {
                ));
            }
        }
+        // A negative tolerance flags a client on time every tick, and so does a cap below minus the
+        // tolerance (the balance rests at the cap); NaN never flags, or never caps the balance. No
+        // negative number of milliseconds means anything, so all are refused.
+        if [self.timer.tolerance_ms, self.timer.max_lag_ms]
+            .iter()
+            .any(|v| !v.is_finite() || *v < 0.0)
+        {
+            return Err(
+                "anticheat.timer: tolerance_ms and max_lag_ms are numbers of milliseconds from 0 up"
+                    .into(),
+            );
+        }
        let tolerance = self.prediction.tolerance;
        if !tolerance.is_finite() || tolerance <= 0.0 {
            return Err("anticheat.prediction: tolerance is a number of blocks above 0".into());
@@ -361,6 +373,26 @@ mod tests {
        assert!(Config::from_server_toml("[anticheat.timer]\nkick = -1\n").is_err());
    }

+    /// A negative `tolerance_ms` flags a client on time every tick, and so does a `max_lag_ms` below
+    /// `-tolerance_ms` (the balance rests at the cap); a NaN turns the check (or its cap) off without a
+    /// word. Every negative or non-finite value is refused, as a negative threshold is.
+    #[test]
+    fn refuses_timer_settings_that_are_not_milliseconds_from_0_up() {
+        for bad in [
+            "tolerance_ms = -1",
+            "tolerance_ms = nan",
+            "tolerance_ms = inf",
+            "max_lag_ms = -1",
+            "max_lag_ms = nan",
+        ] {
+            let text = format!("[anticheat.timer]\n{bad}\n");
+            let e = Config::from_server_toml(&text).expect_err(bad);
+            assert!(e.starts_with("anticheat.timer:"), "{bad}: {e}");
+        }
+        let edge = "[anticheat.timer]\ntolerance_ms = 0\nmax_lag_ms = 0\n";
+        assert!(Config::from_server_toml(edge).is_ok());
+    }
+
    #[test]
    fn levels_rise_decay_and_act_in_order() {
        let mut c = on();
@@ -45,6 +45,11 @@ mod tests {

    /// `seconds` of server ticks of `server_ms` each, with `per_tick` client ticks handled in each.
    fn run(b: &mut Balance, server_ms: f64, per_tick: f64, seconds: f64) -> usize {
+        run_at(b, 20.0, server_ms, per_tick, seconds)
+    }
+
+    /// [`run`] at the tick rate `rate` (`/tick rate`), which the client's ticks follow.
+    fn run_at(b: &mut Balance, rate: f32, server_ms: f64, per_tick: f64, seconds: f64) -> usize {
        let c = TimerConfig::default();
        let mut owed = 0.0;
        let mut flags = 0;
@@ -53,12 +58,31 @@ mod tests {
            owed += per_tick;
            while owed >= 1.0 {
                owed -= 1.0;
-                flags += usize::from(b.tick_end(20.0, &c).is_some());
+                flags += usize::from(b.tick_end(rate, &c).is_some());
            }
        }
        flags
    }

+    /// At another tick rate a vanilla client ticks at the rate the server sent it, and each of its
+    /// ticks is worth `1000 / rate` ms: never flagged on time, flagged again and again 1.5 times as fast.
+    #[test]
+    fn the_balance_follows_the_tick_rate() {
+        for rate in [10.0_f32, 60.0] {
+            let tick_ms = 1000.0 / f64::from(rate);
+            assert_eq!(
+                run_at(&mut Balance::default(), rate, tick_ms, 1.0, 600.0),
+                0,
+                "on time at {rate}"
+            );
+            // Half a tick ahead every server tick: 75 flags in a minute at 10 a second, 94 at 60.
+            let flags = run_at(&mut Balance::default(), rate, tick_ms, 1.5, 60.0);
+            assert!(flags >= 50, "1.5 times as fast at {rate}: {flags} flags");
+        }
+        // The rate counts: at 10 a second, a client sending 20 ticks a second is twice as fast.
+        assert!(run_at(&mut Balance::default(), 10.0, 100.0, 2.0, 60.0) >= 50);
+    }
+
    #[test]
    fn a_vanilla_client_is_never_flagged() {
        let mut b = Balance::default();
@@ -1764,14 +1764,13 @@ fn stack_from_template(template: &Value) -> Option<StackView> {

 /// `RangeSelectItemModel.lastIndexLessOrEqual`.
 fn last_index_less_or_equal(entries: &[(f32, ItemModelNode)], needle: f32) -> Option<usize> {
-    let haystack: Vec<f32> = entries.iter().map(|e| e.0).collect();
-    let found = if haystack.len() < 16 {
-        haystack
+    let found = if entries.len() < 16 {
+        entries
            .iter()
-            .position(|h| *h > needle)
-            .map_or(haystack.len() as i64 - 1, |i| i as i64 - 1)
+            .position(|e| e.0 > needle)
+            .map_or(entries.len() as i64 - 1, |i| i as i64 - 1)
    } else {
-        match binary_search(&haystack, needle) {
+        match binary_search(entries, needle) {
            Ok(index) => index as i64,
            Err(insertion) => insertion as i64 - 1,
        }
@@ -1780,8 +1779,8 @@ fn last_index_less_or_equal(entries: &[(f32, ItemModelNode)], needle: f32) -> Op
 }
 /// `Arrays.binarySearch(float[], float)`, including its handling of equal
 /// values (-0.0 below 0.0, NaN above everything).
-fn binary_search(a: &[f32], key: f32) -> std::result::Result<usize, usize> {
-    let (mut low, mut high) = (0i64, a.len() as i64 - 1);
+fn binary_search(entries: &[(f32, ItemModelNode)], key: f32) -> std::result::Result<usize, usize> {
+    let (mut low, mut high) = (0i64, entries.len() as i64 - 1);
    let bits = |v: f32| -> i32 {
        if v.is_nan() {
            0x7fc0_0000
@@ -1791,7 +1790,7 @@ fn binary_search(a: &[f32], key: f32) -> std::result::Result<usize, usize> {
    };
    while low <= high {
        let mid = (low + high) >> 1;
-        let value = a[mid as usize];
+        let value = entries[mid as usize].0;
        if value < key {
            low = mid + 1;
        } else if value > key {
@@ -158,3 +158,61 @@ fn a_patched_stack_reads_its_patch_over_its_items_defaults() {
    }
    assert_eq!(view.to_map(), *merged);
 }
+
+#[test]
+fn last_index_less_or_equal_linear_and_binary() {
+    use super::last_index_less_or_equal;
+    let make = |thresholds: &[f32]| -> Vec<(f32, ItemModelNode)> {
+        thresholds
+            .iter()
+            .map(|&t| (t, ItemModelNode::Empty))
+            .collect()
+    };
+
+    // Empty
+    assert_eq!(last_index_less_or_equal(&[], 0.0), None);
+
+    // Short (< 16): linear search
+    let short = make(&[-1.0, 0.0, 1.0, 2.5, 5.0]);
+    assert_eq!(last_index_less_or_equal(&short, -2.0), None);
+    assert_eq!(last_index_less_or_equal(&short, -1.0), Some(0));
+    assert_eq!(last_index_less_or_equal(&short, -0.5), Some(0));
+    assert_eq!(last_index_less_or_equal(&short, 0.0), Some(1));
+    assert_eq!(last_index_less_or_equal(&short, 2.5), Some(3));
+    assert_eq!(last_index_less_or_equal(&short, 3.0), Some(3));
+    assert_eq!(last_index_less_or_equal(&short, 5.0), Some(4));
+    assert_eq!(last_index_less_or_equal(&short, 10.0), Some(4));
+
+    // Long (>= 16): binary search
+    let thresholds: Vec<f32> = (0..32).map(|i| i as f32 * 10.0).collect();
+    let long = make(&thresholds);
+    assert_eq!(last_index_less_or_equal(&long, -5.0), None);
+    assert_eq!(last_index_less_or_equal(&long, 0.0), Some(0));
+    assert_eq!(last_index_less_or_equal(&long, 5.0), Some(0));
+    assert_eq!(last_index_less_or_equal(&long, 10.0), Some(1));
+    assert_eq!(last_index_less_or_equal(&long, 150.0), Some(15));
+    assert_eq!(last_index_less_or_equal(&long, 155.0), Some(15));
+    assert_eq!(last_index_less_or_equal(&long, 310.0), Some(31));
+    assert_eq!(last_index_less_or_equal(&long, 1000.0), Some(31));
+
+    // Short lists use upper-bound tie behavior, including signed zero.
+    let duplicates = make(&[1.0, 1.0, 2.0]);
+    assert_eq!(last_index_less_or_equal(&duplicates, 1.0), Some(1));
+
+    let zeroes = make(&[-0.0, 0.0]);
+    assert_eq!(last_index_less_or_equal(&zeroes, -0.0), Some(1));
+    assert_eq!(last_index_less_or_equal(&zeroes, 0.0), Some(1));
+
+    // At 16 entries, vanilla returns Arrays.binarySearch's hit, not the last tie.
+    // Expected indices were checked on the JVM.
+    let duplicates = make(&[
+        0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 7.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, 13.0,
+    ]);
+    assert_eq!(last_index_less_or_equal(&duplicates, 7.0), Some(7));
+
+    let zeroes = make(&[
+        -8.0, -7.0, -6.0, -5.0, -4.0, -3.0, -2.0, -0.0, -0.0, 0.0, 0.0, 1.0, 2.0, 3.0, 4.0, 5.0,
+    ]);
+    assert_eq!(last_index_less_or_equal(&zeroes, -0.0), Some(7));
+    assert_eq!(last_index_less_or_equal(&zeroes, 0.0), Some(9));
+}
@@ -9,5 +9,7 @@ description = "The benchmark report format (docs/benchmark-report.md), shared by
 [dependencies]
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
-# The hardware probes shared with telemetry (cores, clocks, drive, VRAM, power, form).
-horizon-telemetry = { path = "../horizon-telemetry", default-features = false }
+# The hardware probes (cores, clocks, drive, VRAM, power, form); a reader of reports (the wasm
+# build of horizon-perf) needs the types below, never the probes.
+[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
+horizon-system = { path = "../horizon-system" }
@@ -0,0 +1,434 @@
+//! Paired A/B comparison of benchmark blocks (docs/benchmark-report.md, "A/B runs").
+
+use std::collections::BTreeMap;
+
+use serde::{Deserialize, Serialize};
+
+use crate::{round, Frames};
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "snake_case")]
+pub enum Verdict {
+    TooFewPairs,
+    WithinNoise,
+    Negligible,
+    Slower,
+    Faster,
+}
+
+/// B against A over paired blocks; lower milliseconds are better.
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct Paired {
+    pub pairs: usize,
+    pub a: f64,
+    pub b: f64,
+    /// Hodges-Lehmann estimate of b - a.
+    pub diff: f64,
+    /// Absent when `a` is zero.
+    pub diff_pct: Option<f64>,
+    /// Exact Wilcoxon signed-rank interval; absent below 6 pairs.
+    pub ci95: Option<[f64; 2]>,
+    pub confidence: Option<f64>,
+    /// Median distance between neighbouring blocks of the same arm.
+    pub noise: Option<f64>,
+    pub verdict: Verdict,
+}
+
+type Getter = fn(&Frames) -> Option<f64>;
+
+fn median(values: &[f64]) -> f64 {
+    let mut v = values.to_vec();
+    v.sort_by(f64::total_cmp);
+    match v.len() {
+        0 => 0.0,
+        n if n % 2 == 1 => v[n / 2],
+        n => (v[n / 2 - 1] + v[n / 2]) / 2.0,
+    }
+}
+
+fn round4(v: f64) -> f64 {
+    (v * 10_000.0).round() / 10_000.0
+}
+
+/// `(a, b)` per pair, `noise` left for the caller.
+pub fn paired(pairs: &[(f64, f64)]) -> Paired {
+    let n = pairs.len();
+    let a = median(&pairs.iter().map(|p| p.0).collect::<Vec<_>>());
+    let b = median(&pairs.iter().map(|p| p.1).collect::<Vec<_>>());
+    let d: Vec<f64> = pairs.iter().map(|p| p.1 - p.0).collect();
+    let mut walsh = Vec::with_capacity(n * (n + 1) / 2);
+    for i in 0..n {
+        for j in i..n {
+            walsh.push((d[i] + d[j]) / 2.0);
+        }
+    }
+    walsh.sort_by(f64::total_cmp);
+    let diff = median(&walsh);
+    let interval = interval(n, &walsh);
+    let verdict = match interval {
+        None => Verdict::TooFewPairs,
+        Some(([lo, hi], _)) if lo <= 0.0 && 0.0 <= hi => Verdict::WithinNoise,
+        Some(_) if diff.abs() < 0.05_f64.max(0.02 * a) => Verdict::Negligible,
+        Some(([lo, _], _)) if lo > 0.0 => Verdict::Slower,
+        Some(_) => Verdict::Faster,
+    };
+    Paired {
+        pairs: n,
+        a: round(a) + 0.0,
+        b: round(b) + 0.0,
+        diff: round(diff) + 0.0,
+        diff_pct: (a != 0.0).then(|| round(100.0 * diff / a) + 0.0),
+        ci95: interval.map(|([lo, hi], _)| [round(lo) + 0.0, round(hi) + 0.0]),
+        confidence: interval.map(|(_, c)| round4(c)),
+        noise: None,
+        verdict,
+    }
+}
+
+/// The widest symmetric interval of the sorted Walsh averages whose tails hold at most 2.5% each, and its confidence.
+fn interval(n: usize, walsh: &[f64]) -> Option<([f64; 2], f64)> {
+    let m = walsh.len();
+    // Null probabilities of T+ (halving is exact in binary, so these are the counts over 2^n).
+    let mut p = vec![0.0f64; m + 1];
+    p[0] = 1.0;
+    for r in 1..=n {
+        for t in (0..=m).rev() {
+            p[t] = (p[t] + if t >= r { p[t - r] } else { 0.0 }) / 2.0;
+        }
+    }
+    let (mut k, mut tail, mut best) = (0, 0.0, 0.0);
+    while k < m {
+        tail += p[k];
+        if tail > 0.025 {
+            break;
+        }
+        k += 1;
+        best = tail;
+    }
+    (k >= 1).then(|| ([walsh[k - 1], walsh[m - k]], 1.0 - 2.0 * best))
+}
+
+/// The result of an A/B run: pairs of blocks in B A A B order, recomputable from the report's `frames`.
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct Ab {
+    pub switch: String,
+    pub a: String,
+    pub b: String,
+    pub pairs: u32,
+    pub block_s: f64,
+    pub warmup_s: f64,
+    /// Block 0 (measured before any switch) lies outside the later B blocks.
+    pub first_block_outside_range: bool,
+    /// By `gpu_p50_ms`, `cpu_p50_ms`, `frame_p50_ms`; a metric missing from any block is left out.
+    pub result: BTreeMap<String, Paired>,
+}
+
+impl Ab {
+    /// Pairs the `ab.a`/`ab.b` entries of `frames` by `repeat` (0, 1, 2...): pair k is blocks 2k and 2k+1.
+    pub fn from_frames(
+        switch: &str,
+        a: &str,
+        b: &str,
+        block_s: f64,
+        warmup_s: f64,
+        frames: &[Frames],
+    ) -> Result<Ab, String> {
+        let mut blocks: Vec<&Frames> = frames
+            .iter()
+            .filter(|f| f.phase == "ab.a" || f.phase == "ab.b")
+            .collect();
+        blocks.sort_by_key(|f| f.repeat);
+        if blocks.is_empty()
+            || !blocks.len().is_multiple_of(2)
+            || blocks
+                .iter()
+                .enumerate()
+                .any(|(i, f)| f.repeat as usize != i)
+        {
+            return Err("A/B blocks must be numbered 0..N with N even".to_owned());
+        }
+        if blocks.chunks(2).any(|p| p[0].phase == p[1].phase) {
+            return Err("each pair needs one ab.a and one ab.b block".to_owned());
+        }
+        let pairs = blocks.len() / 2;
+        let metrics: [(&str, Getter); 3] = [
+            ("gpu_p50_ms", |f| f.gpu_p50_ms),
+            ("cpu_p50_ms", |f| f.cpu_p50_ms),
+            ("frame_p50_ms", |f| Some(f.p50_ms)),
+        ];
+        let mut result = BTreeMap::new();
+        let mut series: BTreeMap<&str, Vec<f64>> = BTreeMap::new();
+        for (name, get) in metrics {
+            let Some(values) = blocks.iter().map(|f| get(f)).collect::<Option<Vec<f64>>>() else {
+                continue;
+            };
+            let by_arm: Vec<(f64, f64)> = blocks
+                .chunks(2)
+                .zip(values.chunks(2))
+                .map(|(p, v)| {
+                    if p[0].phase == "ab.a" {
+                        (v[0], v[1])
+                    } else {
+                        (v[1], v[0])
+                    }
+                })
+                .collect();
+            let mut stat = paired(&by_arm);
+            let gaps: Vec<f64> = (1..values.len().saturating_sub(1))
+                .step_by(2)
+                .filter(|&i| blocks[i].phase == blocks[i + 1].phase)
+                .map(|i| (values[i] - values[i + 1]).abs())
+                .collect();
+            stat.noise = (!gaps.is_empty()).then(|| round(median(&gaps)) + 0.0);
+            result.insert(name.to_owned(), stat);
+            series.insert(name, values);
+        }
+        let first_block_outside_range = series
+            .get("gpu_p50_ms")
+            .or_else(|| series.get("frame_p50_ms"))
+            .is_some_and(|values| {
+                let later: Vec<f64> = (1..values.len())
+                    .filter(|&i| blocks[i].phase == "ab.b")
+                    .map(|i| values[i])
+                    .collect();
+                blocks[0].phase == "ab.b"
+                    && !later.is_empty()
+                    && (values[0] < later.iter().copied().fold(f64::INFINITY, f64::min)
+                        || values[0] > later.iter().copied().fold(f64::NEG_INFINITY, f64::max))
+            });
+        Ok(Ab {
+            switch: switch.to_owned(),
+            a: a.to_owned(),
+            b: b.to_owned(),
+            pairs: pairs as u32,
+            block_s,
+            warmup_s,
+            first_block_outside_range,
+            result,
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::{App, Kind, Report};
+
+    // Expected values: exact-rational Walsh averages and a brute-force sign enumeration, run once outside this code.
+    fn check(
+        a: &[f64],
+        b: &[f64],
+        diff: f64,
+        ci: Option<[f64; 2]>,
+        conf: Option<f64>,
+        verdict: Verdict,
+    ) {
+        let pairs: Vec<(f64, f64)> = a.iter().copied().zip(b.iter().copied()).collect();
+        let p = paired(&pairs);
+        assert_eq!(
+            (p.pairs, p.diff, p.ci95, p.confidence, p.verdict),
+            (a.len(), diff, ci, conf, verdict),
+            "{b:?}"
+        );
+    }
+
+    #[test]
+    fn the_decided_vectors() {
+        use Verdict::*;
+        let z = |n: usize| vec![0.0; n];
+        let up = |n: usize| (1..=n).map(|v| v as f64).collect::<Vec<_>>();
+        check(&z(8), &up(8), 4.5, Some([2.0, 7.0]), Some(0.9609), Slower);
+        let wobble = [-0.3, 0.2, -0.1, 0.4, -0.2, 0.1, 0.3, -0.4];
+        check(
+            &z(8),
+            &wobble,
+            0.0,
+            Some([-0.3, 0.3]),
+            Some(0.9609),
+            WithinNoise,
+        );
+        check(&z(6), &up(6), 3.5, Some([1.0, 6.0]), Some(0.9688), Slower);
+        check(&z(5), &up(5), 3.0, None, None, TooFewPairs);
+        let a = [3.65, 3.70, 3.62, 3.68, 3.66, 3.71, 3.63, 3.69];
+        let b = [5.63, 5.60, 5.70, 5.58, 5.65, 5.62, 5.66, 5.61];
+        check(&a, &b, 1.96, Some([1.905, 2.03]), Some(0.9609), Slower);
+        let tiny: Vec<f64> = (1..=8).map(|v| 10.0 + v as f64 / 100.0).collect();
+        check(
+            &[10.0; 8],
+            &tiny,
+            0.045,
+            Some([0.02, 0.07]),
+            Some(0.9609),
+            Negligible,
+        );
+        let down: Vec<f64> = up(8).iter().map(|_| 0.0).collect();
+        check(
+            &up(8),
+            &down,
+            -4.5,
+            Some([-7.0, -2.0]),
+            Some(0.9609),
+            Faster,
+        );
+        let mixed = [0.5, -0.2, 0.0, 0.3, 0.9, -0.1, 0.4];
+        check(
+            &z(7),
+            &mixed,
+            0.225,
+            Some([-0.1, 0.65]),
+            Some(0.9531),
+            WithinNoise,
+        );
+        let ten = [0.3, -0.1, 0.8, 0.2, -0.5, 0.6, 0.1, 0.4, 0.7, 0.05];
+        check(
+            &z(10),
+            &ten,
+            0.25,
+            Some([-0.025, 0.55]),
+            Some(0.9512),
+            WithinNoise,
+        );
+    }
+
+    #[test]
+    fn medians_percent_and_empty_input() {
+        let a = [3.65, 3.70, 3.62, 3.68, 3.66, 3.71, 3.63, 3.69];
+        let b = [5.63, 5.60, 5.70, 5.58, 5.65, 5.62, 5.66, 5.61];
+        let p = paired(&a.iter().copied().zip(b).collect::<Vec<_>>());
+        assert_eq!(
+            (p.a, p.b, p.diff_pct, p.noise),
+            (3.67, 5.625, Some(53.406), None)
+        );
+        assert_eq!(
+            paired(&[(0.0, 1.0); 8]).diff_pct,
+            None,
+            "no percent of zero"
+        );
+        assert_eq!(paired(&[]).verdict, Verdict::TooFewPairs);
+    }
+
+    fn block(phase: &str, repeat: u32, frame: f64, cpu: Option<f64>, gpu: Option<f64>) -> Frames {
+        Frames {
+            phase: phase.into(),
+            repeat,
+            frames: 100,
+            seconds: 4.0,
+            avg_fps: 250.0,
+            low_1pct_fps: 100.0,
+            low_01pct_fps: 90.0,
+            p50_ms: frame,
+            p95_ms: frame + 1.0,
+            p99_ms: frame + 2.0,
+            p999_ms: frame + 3.0,
+            max_ms: frame + 4.0,
+            cpu_p50_ms: cpu,
+            gpu_p50_ms: gpu,
+            histogram: vec![0; crate::HISTOGRAM_EDGES_MS.len()],
+        }
+    }
+
+    // B A A B B A A B B A A B, as gpu milliseconds; frame time is gpu + 1.
+    fn twelve(first_b: f64) -> Vec<Frames> {
+        let gpu = [
+            first_b, 3.0, 3.2, 5.0, 5.2, 3.1, 3.1, 5.1, 5.4, 3.4, 3.3, 5.3,
+        ];
+        gpu.iter()
+            .enumerate()
+            .map(|(i, &g)| {
+                block(
+                    if matches!(i % 4, 0 | 3) {
+                        "ab.b"
+                    } else {
+                        "ab.a"
+                    },
+                    i as u32,
+                    g + 1.0,
+                    Some(g / 2.0),
+                    Some(g),
+                )
+            })
+            .collect()
+    }
+
+    fn from(frames: &[Frames]) -> Result<Ab, String> {
+        Ab::from_frames("gpu-culling", "off", "on", 4.0, 2.0, frames)
+    }
+
+    #[test]
+    fn noise_and_the_first_block_flag() {
+        let ab = from(&twelve(6.4)).unwrap();
+        assert!(
+            ab.first_block_outside_range,
+            "6.4 is 1 ms above the other B blocks"
+        );
+        let gpu = &ab.result["gpu_p50_ms"];
+        // Neighbours (1,2) (3,4) (5,6) (7,8) (9,10): 0.2 0.2 0 0.3 0.1.
+        assert_eq!(
+            (gpu.pairs, gpu.a, gpu.b, gpu.noise),
+            (6, 3.15, 5.25, Some(0.2))
+        );
+        assert_eq!(
+            (gpu.ci95, gpu.verdict),
+            (Some([1.8, 3.4]), Verdict::Slower),
+            "every d is positive: min and max Walsh averages"
+        );
+        assert_eq!(ab.result["cpu_p50_ms"].noise, Some(0.1));
+        assert_eq!(
+            (ab.pairs, ab.switch.as_str(), ab.a.as_str(), ab.b.as_str()),
+            (6, "gpu-culling", "off", "on")
+        );
+        assert!(!from(&twelve(5.2)).unwrap().first_block_outside_range);
+    }
+
+    #[test]
+    fn a_metric_missing_from_one_block_is_left_out() {
+        let mut frames = twelve(5.2);
+        frames[7].gpu_p50_ms = None;
+        let ab = from(&frames).unwrap();
+        assert_eq!(
+            ab.result.keys().collect::<Vec<_>>(),
+            ["cpu_p50_ms", "frame_p50_ms"]
+        );
+        let mut frames = twelve(6.4);
+        frames[0].gpu_p50_ms = None;
+        frames[0].p50_ms = 6.0;
+        assert!(
+            !from(&frames).unwrap().first_block_outside_range,
+            "frame time 6.0 is inside 6.0..6.4 of the later B blocks"
+        );
+    }
+
+    #[test]
+    fn blocks_that_do_not_pair_are_refused() {
+        assert!(from(&[]).is_err());
+        assert!(from(&twelve(5.2)[..11]).is_err(), "odd number of blocks");
+        let mut frames = twelve(5.2);
+        frames[1].phase = "ab.b".into();
+        assert!(from(&frames).is_err(), "a pair of two B blocks");
+        let mut frames = twelve(5.2);
+        frames[3].repeat = 9;
+        assert!(from(&frames).is_err(), "a gap in the numbering");
+    }
+
+    #[test]
+    fn a_report_with_ab_round_trips_and_old_ones_still_parse() {
+        let mut r = Report::new(Kind::Game, App::default());
+        let old = r.to_json();
+        assert!(!old.contains("\"ab\""));
+        assert_eq!(Report::parse(&old).unwrap().ab, None);
+        r.frames = twelve(5.2);
+        r.ab = Some(from(&r.frames).unwrap());
+        let json = r.to_json();
+        assert_eq!(Report::parse(&json).unwrap(), r);
+        assert!(
+            json.contains("\"first_block_outside_range\": false")
+                && json.contains("\"verdict\": \"slower\"")
+        );
+        assert_eq!(r.for_upload().ab, r.ab);
+        let mut few = paired(&[(1.0, 2.0); 3]);
+        few.noise = None;
+        assert!(serde_json::to_string(&few)
+            .unwrap()
+            .contains("\"ci95\":null,\"confidence\":null"));
+    }
+}
@@ -1,7 +1,8 @@
 //! The machine a report was measured on. CPU, RAM and OS are detected here; the GPU and the display
 //! come from the program that rendered (the game knows its adapter, the launcher its window).

-use horizon_telemetry::system::command_output as output;
+#[cfg(any(target_os = "macos", target_os = "linux"))]
+use horizon_system::command_output as output;
 use serde::{Deserialize, Serialize};

 #[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize)]
@@ -61,6 +62,7 @@ pub struct Display {
    pub refresh_hz: Option<u32>,
 }

+#[cfg(not(target_arch = "wasm32"))]
 impl Hardware {
    pub fn detect() -> Hardware {
        let probes = probes();
@@ -68,12 +70,12 @@ impl Hardware {
            os: std::env::consts::OS.to_owned(),
            os_version: os_version(),
            arch: std::env::consts::ARCH.to_owned(),
-            cpu: cpu(),
+            cpu: horizon_system::cpu(),
            cpu_threads: std::thread::available_parallelism().ok().map(|n| n.get()),
            cpu_cores: probes.cores,
            cpu_base_mhz: probes.base,
            cpu_boost_mhz: probes.boost,
-            ram_mb: ram_bytes().map(|b| b >> 20),
+            ram_mb: horizon_system::ram_bytes().map(|b| b >> 20),
            storage: None,
            form: probes.form,
            gpu: None,
@@ -84,13 +86,14 @@ impl Hardware {
    /// [`Hardware::detect`] with the kind of drive `game_dir` is on.
    pub fn detect_in(game_dir: &std::path::Path) -> Hardware {
        Hardware {
-            storage: horizon_telemetry::system::storage(game_dir).map(str::to_owned),
+            storage: horizon_system::storage(game_dir).map(str::to_owned),
            ..Hardware::detect()
        }
    }
 }

-/// What the telemetry probes read (`horizon_telemetry::system`).
+#[cfg(not(target_arch = "wasm32"))]
+/// What `horizon_system::Machine` reads.
 struct Probes {
    cores: Option<u16>,
    base: Option<u32>,
@@ -98,95 +101,31 @@ struct Probes {
    form: Option<String>,
 }

+#[cfg(not(target_arch = "wasm32"))]
 fn probes() -> Probes {
-    let s = horizon_telemetry::payload::System::detect();
+    let s = horizon_system::Machine::detect();
    let some = |n: u32| (n > 0).then_some(n);
    Probes {
        cores: (s.cores > 0).then_some(s.cores),
        base: some(s.cpu_base_mhz),
        boost: some(s.cpu_boost_mhz),
-        form: (!s.form.is_empty()).then_some(s.form),
-    }
-}
-
-/// The one-minute load average: above about the number of threads the machine was busy.
-pub fn load_average() -> Option<f64> {
-    if cfg!(target_os = "macos") {
-        // "{ 1.23 1.10 1.00 }"
-        output("sysctl", &["-n", "vm.loadavg"])?
-            .trim_start_matches('{')
-            .split_whitespace()
-            .next()?
-            .parse()
-            .ok()
-    } else {
-        std::fs::read_to_string("/proc/loadavg")
-            .ok()?
-            .split_whitespace()
-            .next()?
-            .parse()
-            .ok()
+        form: (!s.form.is_empty()).then(|| s.form.to_owned()),
    }
 }

+#[cfg(not(target_arch = "wasm32"))]
 /// `ac` or `battery`; `None` where it can't be read (and on machines without a battery on Linux).
 pub fn power_source() -> Option<&'static str> {
-    horizon_telemetry::system::power()
-}
-
-/// Resident memory of a process, in bytes (macOS, Linux).
-pub fn rss_bytes(pid: u32) -> Option<u64> {
-    if cfg!(target_os = "macos") {
-        return output("ps", &["-o", "rss=", "-p", &pid.to_string()])?
-            .parse::<u64>()
-            .ok()
-            .map(|kb| kb * 1024);
-    }
-    let status = std::fs::read_to_string(format!("/proc/{pid}/status")).ok()?;
-    let line = status.lines().find(|l| l.starts_with("VmRSS:"))?;
-    line.split_whitespace()
-        .nth(1)?
-        .parse::<u64>()
-        .ok()
-        .map(|kb| kb * 1024)
-}
-
-/// CPU time a process has used, user and system, in seconds (macOS, Linux).
-pub fn cpu_seconds(pid: u32) -> Option<f64> {
-    if cfg!(target_os = "macos") {
-        // "[[dd-]hh:]mm:ss.cc"
-        let time = output("ps", &["-o", "time=", "-p", &pid.to_string()])?;
-        let (rest, days) = match time.split_once('-') {
-            Some((d, rest)) => (rest.to_owned(), d.parse::<f64>().ok()?),
-            None => (time, 0.0),
-        };
-        let seconds = rest.split(':').try_fold(0.0, |acc, part| {
-            part.parse::<f64>().ok().map(|v| acc * 60.0 + v)
-        })?;
-        return Some(days * 86_400.0 + seconds);
-    }
-    // utime and stime, fields 14 and 15, in clock ticks (100 per second on Linux).
-    let stat = std::fs::read_to_string(format!("/proc/{pid}/stat")).ok()?;
-    let fields: Vec<&str> = stat.rsplit_once(')')?.1.split_whitespace().collect();
-    let ticks: f64 = fields.get(11)?.parse::<f64>().ok()? + fields.get(12)?.parse::<f64>().ok()?;
-    Some(ticks / 100.0)
+    horizon_system::power()
 }

+#[cfg(not(target_arch = "wasm32"))]
 #[cfg(target_os = "macos")]
 fn os_version() -> Option<String> {
    output("sw_vers", &["-productVersion"])
 }

-#[cfg(target_os = "macos")]
-fn cpu() -> Option<String> {
-    output("sysctl", &["-n", "machdep.cpu.brand_string"])
-}
-
-#[cfg(target_os = "macos")]
-fn ram_bytes() -> Option<u64> {
-    output("sysctl", &["-n", "hw.memsize"])?.parse().ok()
-}
-
+#[cfg(not(target_arch = "wasm32"))]
 #[cfg(target_os = "linux")]
 fn os_version() -> Option<String> {
    let release = std::fs::read_to_string("/etc/os-release").ok()?;
@@ -199,22 +138,7 @@ fn os_version() -> Option<String> {
    })
 }

-#[cfg(target_os = "linux")]
-fn cpu() -> Option<String> {
-    let info = std::fs::read_to_string("/proc/cpuinfo").ok()?;
-    // x86 names the CPU per core; arm64 only gives the core's implementer and part.
-    horizon_telemetry::system::linux_cpu_name(&info)
-}
-
-#[cfg(target_os = "linux")]
-fn ram_bytes() -> Option<u64> {
-    let info = std::fs::read_to_string("/proc/meminfo").ok()?;
-    let kb = key_value(&info, "MemTotal", ':')?
-        .trim_end_matches("kB")
-        .trim();
-    kb.parse::<u64>().ok().map(|kb| kb * 1024)
-}
-
+#[cfg(not(target_arch = "wasm32"))]
 #[cfg(target_os = "linux")]
 fn key_value<'a>(text: &'a str, key: &str, sep: char) -> Option<&'a str> {
    text.lines().find_map(|line| {
@@ -223,45 +147,19 @@ fn key_value<'a>(text: &'a str, key: &str, sep: char) -> Option<&'a str> {
    })
 }

+#[cfg(not(target_arch = "wasm32"))]
 #[cfg(target_os = "windows")]
 fn os_version() -> Option<String> {
-    horizon_telemetry::system::windows_version()
-}
-
-#[cfg(target_os = "windows")]
-fn cpu() -> Option<String> {
-    horizon_telemetry::system::windows_cpu()
-}
-
-#[cfg(target_os = "windows")]
-fn ram_bytes() -> Option<u64> {
-    let out = output(
-        "powershell",
-        &[
-            "-NoProfile",
-            "-Command",
-            "(Get-CimInstance Win32_ComputerSystem).TotalPhysicalMemory",
-        ],
-    )?;
-    out.parse().ok()
+    horizon_system::windows_version()
 }

+#[cfg(not(target_arch = "wasm32"))]
 #[cfg(not(any(target_os = "macos", target_os = "linux", target_os = "windows")))]
 fn os_version() -> Option<String> {
    None
 }

-#[cfg(not(any(target_os = "macos", target_os = "linux", target_os = "windows")))]
-fn cpu() -> Option<String> {
-    None
-}
-
-#[cfg(not(any(target_os = "macos", target_os = "linux", target_os = "windows")))]
-fn ram_bytes() -> Option<u64> {
-    None
-}
-
-#[cfg(test)]
+#[cfg(all(test, not(target_arch = "wasm32")))]
 mod tests {
    use super::*;

@@ -274,9 +172,6 @@ mod tests {
            assert!(hw.cpu.is_some(), "{hw:?}");
            assert!(hw.ram_mb.unwrap() > 256, "{hw:?}");
            assert!(hw.os_version.is_some(), "{hw:?}");
-            assert!(load_average().is_some());
-            assert!(rss_bytes(std::process::id()).unwrap() > 1 << 20);
-            assert!(cpu_seconds(std::process::id()).unwrap() >= 0.0);
        }
    }

@@ -11,9 +11,15 @@ use std::time::{SystemTime, UNIX_EPOCH};

 use serde::{Deserialize, Serialize};

+pub mod compare;
 mod hardware;

-pub use hardware::{cpu_seconds, load_average, power_source, rss_bytes, Display, Gpu, Hardware};
+#[cfg(not(target_arch = "wasm32"))]
+pub use hardware::power_source;
+pub use hardware::{Display, Gpu, Hardware};
+/// The process probes, from the platform (`horizon-system`).
+#[cfg(not(target_arch = "wasm32"))]
+pub use horizon_system::{cpu_seconds, load_average, rss_bytes};

 pub const FORMAT: &str = "horizon-benchmark-report";
 pub const VERSION: u32 = 1;
@@ -234,6 +240,9 @@ pub struct Report {
    pub metrics: BTreeMap<String, Summary>,
    #[serde(default)]
    pub frames: Vec<Frames>,
+    /// Present in A/B runs only.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub ab: Option<compare::Ab>,
    /// Local only: a name the person running it chose.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub label: Option<String>,
@@ -244,6 +253,7 @@ pub struct Report {

 impl Report {
    /// An empty report for this machine, created now.
+    #[cfg(not(target_arch = "wasm32"))]
    pub fn new(kind: Kind, app: App) -> Report {
        Self::with_hardware(kind, app, Hardware::detect())
    }
@@ -261,6 +271,7 @@ impl Report {
            conditions: Conditions::default(),
            metrics: BTreeMap::new(),
            frames: Vec::new(),
+            ab: None,
            label: None,
            local: Vec::new(),
        }
@@ -952,8 +952,16 @@ mod tests {
        (en, seen)
    }

-    #[test]
-    fn every_horizon_key_the_code_names_is_in_en_us() {
+    /// The crates whose `horizon.` keys must be in en_us.json.
+    const CLIENT_CRATES: [&str; 4] = [
+        "horizon-client",
+        "horizon-client-render",
+        "horizon-client-core",
+        "horizon-client-input",
+    ];
+
+    /// The Rust sources of `krates`, or of every crate under `crates/` when it is empty.
+    fn crate_sources(krates: &[&str]) -> Vec<std::path::PathBuf> {
        fn rust_files(dir: &std::path::Path, out: &mut Vec<std::path::PathBuf>) {
            for entry in std::fs::read_dir(dir).into_iter().flatten().flatten() {
                let path = entry.path();
@@ -964,27 +972,68 @@ mod tests {
                }
            }
        }
+        let crates = std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("..");
+        let mut files = Vec::new();
+        if krates.is_empty() {
+            for entry in std::fs::read_dir(&crates).unwrap().flatten() {
+                rust_files(&entry.path().join("src"), &mut files);
+            }
+        }
+        for krate in krates {
+            rust_files(&crates.join(krate).join("src"), &mut files);
+        }
+        assert!(files.len() > 100, "found only {} sources", files.len());
+        files
+    }
+
+    /// A sentence key (the English text itself, not a `horizon.` id) that no
+    /// source names as a string literal is text the game no longer shows: its
+    /// rewording left it behind in every language (#13802).
+    #[test]
+    fn every_sentence_key_in_en_us_is_one_the_code_names() {
+        let en: HashMap<String, String> = serde_json::from_str(
+            &std::fs::read_to_string(bundled_dir().join("en_us.json")).unwrap(),
+        )
+        .unwrap();
+        // Every crate: a feature moved out of the client crates keeps its strings.
+        let code: String = crate_sources(&[])
+            .iter()
+            .map(|file| std::fs::read_to_string(file).unwrap())
+            .collect();
+        let sentences: Vec<&String> = en.keys().filter(|k| !k.starts_with("horizon.")).collect();
+        assert!(
+            sentences.len() > 100,
+            "found only {} sentence keys",
+            sentences.len()
+        );
+        // A JSON string literal escapes `"` and `\` as Rust's does.
+        let mut dead: Vec<&str> = sentences
+            .into_iter()
+            .filter(|key| !code.contains(&serde_json::to_string(key).unwrap()))
+            .map(String::as_str)
+            .collect();
+        dead.sort_unstable();
+        assert!(
+            dead.is_empty(),
+            "en_us.json keys no code asks for: {dead:#?}"
+        );
+    }
+
+    #[test]
+    fn every_horizon_key_the_code_names_is_in_en_us() {
        let english = |dir: &std::path::Path| -> HashMap<String, String> {
            serde_json::from_str(&std::fs::read_to_string(dir.join("en_us.json")).unwrap()).unwrap()
        };
        let mut en = english(&bundled_dir());
-        let crates = std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("..");
-        let mut files = Vec::new();
-        for krate in [
-            "horizon-client",
-            "horizon-client-render",
-            "horizon-client-core",
-        ] {
-            rust_files(&crates.join(krate).join("src"), &mut files);
-        }
+        let mut krates = CLIENT_CRATES.to_vec();
        // A crate that ships lang files names its keys in its own sources.
-        for (name, dir) in crate_lang_dirs() {
-            en.extend(english(&dir));
-            rust_files(&crates.join(name).join("src"), &mut files);
+        let lang_dirs = crate_lang_dirs();
+        for (name, dir) in &lang_dirs {
+            en.extend(english(dir));
+            krates.push(name);
        }
-        assert!(files.len() > 100, "found only {} sources", files.len());
        let mut found = 0;
-        for file in files {
+        for file in crate_sources(&krates) {
            let text = std::fs::read_to_string(&file).unwrap();
            for (at, _) in text.match_indices("\"horizon.") {
                let rest = &text[at + 1..];
@@ -61,6 +61,8 @@ pub enum ClickEvent {
    /// A local file to open with the system handler.
    /// Only allow this in locally constructed messages, never server/LAN text.
    OpenFile(String),
+    /// A `/profiler` line the client's own buttons run; never decoded from a server's text, so only they reach the local profiler.
+    Profiler(String),
 }

 /// A non-character `minecraft:object` embedded in a text component.
@@ -202,7 +204,12 @@ impl Text {
        }
    }
    pub fn styled(s: impl Into<String>, style: Style) -> Self {
-        Self::literal(s).with_style(&style)
+        let mut text = Self::literal(s).with_style(&style);
+        // `inherit` never passes an object on, but a styled span's own style carries it.
+        for span in &mut text.spans {
+            span.style.inline_object.clone_from(&style.inline_object);
+        }
+        text
    }
    pub fn colored(s: impl Into<String>, color: u32) -> Self {
        Self::styled(s, Style::color(color))
@@ -619,6 +626,9 @@ fn style_json(style: &Style) -> Vec<(String, Value)> {
                event
            }
            ClickEvent::OpenFile(path) => json!({ "action": "open_file", "path": path }),
+            ClickEvent::Profiler(command) => {
+                json!({ "action": "run_command", "command": command })
+            }
        };
        out.push(("click_event".to_owned(), event));
    }
@@ -772,6 +782,27 @@ pub fn format_translation(template: &str, args: &[Text]) -> Text {
 mod tests {
    use super::*;
    #[test]
+    fn a_styled_object_span_keeps_its_object_through_append_and_slice() {
+        let object = InlineObject::Atlas {
+            atlas: "minecraft:gui".into(),
+            sprite: "horizon:gui/mark".into(),
+            fallback: "H".into(),
+        };
+        let sprite = Text::styled(
+            "\u{fffc}",
+            Style {
+                inline_object: Some(object.clone()),
+                ..Style::color(WHITE)
+            },
+        );
+        let line = Text::colored("[", DARK_GRAY)
+            .append(sprite)
+            .append(Text::colored("] ", DARK_GRAY));
+        let line = line.slice(0, 3);
+        assert_eq!(line.spans[1].style.inline_object, Some(object));
+        assert_eq!(line.plain(), "[H]");
+    }
+    #[test]
    fn appending_builds_the_same_tree_in_linear_time() {
        // A styled text is wrapped once, so its style doesn't reach what follows; a plain one
        // takes the siblings itself; a copy taken before an append keeps its own tree.
@@ -27,6 +27,8 @@ horizon-mcp = { path = "../horizon-mcp" }
 # The server thread ahead of the workers (MinecraftServer.spin's Thread.setPriority).
 horizon-optifine = { path = "../horizon-optifine" }
 horizon-threads = { path = "../horizon-threads" }
+# The .hzperf capture format and writer (docs/perf-platform.md).
+horizon-perf-format = { path = "../horizon-perf-format" }
 # One pool of helper threads for the server tick's parallel phases (`parallel.rs`): threads made
 # once, not for every phase of every tick.
 rayon = "1.10"
@@ -91,6 +93,8 @@ rustix = { version = "1", default-features = false, features = ["std", "time", "
 [target.'cfg(windows)'.dependencies]
 # Use the registered URI handler without routing links through Explorer/cmd.
 open = { version = "5.4.5", features = ["shellexecute-on-windows"] }
+# Resolve virtualized folders to shell-compatible physical paths (desktop.rs).
+dunce = "1.0.5"
 # DirectX 12, where Vulkan has no adapter or device, or by choice (`graphicsApi`, graphics.rs).
 # Shaders compile with FXC (d3dcompiler_47.dll, part of Windows), or on integrated GPUs with DXC
 # (dxcompiler.dll beside the game, gfx/dx12_compiler.rs).
@@ -110,6 +114,8 @@ wgpu = { version = "30.0.1", default-features = false, features = ["gles"] }

 [features]
 default = ["audio", "controllers"]
+# Dev-only: the ignored tracker-send benchmark uses the executable's allocator.
+tracker-send-bench = []
 # Sound output. Without it (and `controllers`) the program links neither libasound nor libudev on
 # Linux: the server build (`--no-default-features`, released as horizon-engine; docs/server.md).
 audio = ["horizon-client-render/audio"]
@@ -130,6 +136,8 @@ workspace = true
 horizon-theme = { path = "../horizon-theme" }
 horizon-client-render = { path = "../horizon-client-render", features = ["test-support"] }
 horizon-items = { path = "../horizon-items", features = ["test-support"] }
+# Reads back the captures the server_perf tests write.
+horizon-perf = { path = "../horizon-perf" }
 # Every WGSL shader translated as wgpu's DirectX 12 backend does (gfx.rs tests).
 naga = { version = "30.0.1", features = ["wgsl-in", "hlsl-out", "msl-out", "spv-out"] }

@@ -23,6 +23,7 @@ horizon-narrator = { path = "../horizon-narrator" }
 # OptiFine-format pack files: random entity textures (hud.rs), connected textures
 # (connected.rs) and custom item texture rules (cit.rs).
 horizon-optifine = { path = "../horizon-optifine" }
+horizon-perf-format = { path = "../horizon-perf-format" }
 horizon-polytone = { path = "../horizon-polytone" }
 horizon-protocol = { path = "../horizon-protocol" }
 horizon-shader-api = { path = "../horizon-shader-api" }
@@ -74,6 +75,9 @@ wgpu = { version = "30.0.1", default-features = false, features = ["gles"] }
 audio = ["dep:cpal"]
 # Helpers horizon-client's tests build their fixtures with.
 test-support = []
+# The `scene_replay` example's allocator counts allocations (horizon-threads' `alloc-count`).
+alloc-count = ["horizon-threads/alloc-count"]
+
 # horizon-client's `horizon-extras`: asking the device for hardware ray tracing on request
 # (`gfx/ray_query.rs`, `HORIZON_RAY_TRACING=1`). Without it the device is requested as without
 # the variable.
@@ -83,6 +87,7 @@ horizon-extras = []
 workspace = true

 [dev-dependencies]
+horizon-perf = { path = "../horizon-perf" }
 # Tests: a TrueType font to load, and the design system the menus' motion curves match.
 horizon-theme = { path = "../horizon-theme" }
 horizon-items = { path = "../horizon-items", features = ["test-support"] }
@@ -6,13 +6,14 @@
 //! [--mipmaps N] [--lod-distance CHUNKS] [--render-distance CHUNKS] [--size WxH]
 //! [--section-draws flat|indirect] [--section-cull on|off] [--section-sides on|off]
 //! [--gpu-culling on|off] [--root RESOURCES] [--screenshot PNG]
-//! [--world SAVE --leaf-culling MODE] [--memory on]`
+//! [--world SAVE --leaf-culling MODE] [--memory on] [--gpu-detail on|off]`
 //! `--screenshot` saves the first view's last frame, after the timed frames.
 //! `--world` meshes the captured sections again from that save's region files
 //! (blocks, biomes and saved light; `ao`, `biomeBlendRadius` and `cutoutLeaves`
 //! from `./options.txt`) with `--leaf-culling` (default `off`), so a mesher
 //! change can be measured on the captured view. A section whose 3x3 columns are
 //! not all saved keeps its captured mesh.
+//! `--gpu-detail on` adds GPU culling's dispatch times and, on Vulkan, the world passes' counters.
 //! `--memory on` adds the renderer's largest GPU resources and, on macOS, the process's
 //! physical footprint by category (`footprint`), taken after the timed frames.
 use horizon_client_render::{
@@ -24,6 +25,7 @@ use horizon_client_render::{
    gfx::{
        PreparedTextures, Renderer, ScreenshotRequest,
        capture::{self, AtlasCheck, Scene},
+        pack_timing,
        panorama::Faces,
    },
    graphics::LeafCullingMode,
@@ -61,7 +63,10 @@ use winit::{
 // The game's allocator, so that `--memory`'s footprint is the game's: the system heap kept
 // gigabytes of the meshes `--world` frees dirty.
 #[global_allocator]
-static ALLOCATOR: horizon_threads::Allocator = horizon_threads::ALLOCATOR;
+static ALLOCATOR: horizon_threads::GameAllocator = horizon_threads::GAME_ALLOCATOR;
+
+/// Frames drawn with detail on, enough for a few timed frames of each kind.
+const DETAIL_FRAMES: usize = 60;

 #[derive(Default)]
 struct Options {
@@ -84,6 +89,7 @@ struct Options {
    world: Option<PathBuf>,
    leaf_culling: LeafCullingMode,
    memory: bool,
+    gpu_detail: bool,
 }

 fn on_off(value: &str) -> Result<bool, String> {
@@ -136,6 +142,7 @@ fn options() -> Result<Options, String> {
            "--screenshot" => o.screenshot = Some(value.into()),
            "--world" => o.world = Some(value.into()),
            "--memory" => o.memory = on_off(&value)?,
+            "--gpu-detail" => o.gpu_detail = on_off(&value)?,
            "--leaf-culling" => {
                o.leaf_culling = LeafCullingMode::ALL
                    .into_iter()
@@ -400,6 +407,23 @@ fn replay(window: Arc<Window>) -> Result<(), Box<dyn std::error::Error>> {
                None => notes.push("screenshot: not saved".into()),
            }
        }
+        let mut detail = serde_json::Map::new();
+        if o.gpu_detail {
+            renderer.set_pass_detail(true);
+            for _ in 0..DETAIL_FRAMES {
+                draw(&mut renderer)?;
+            }
+            detail.insert(
+                "gpu_pass_parts_median_ms".into(),
+                pack_timing::parts_json(&renderer.own_pass_parts()),
+            );
+            let unit = renderer.pass_detail_support().and_then(|s| s.fragment_unit);
+            detail.insert(
+                "gpu_counters_median".into(),
+                pack_timing::counters_by_pass_json(&renderer.own_pass_counters(), unit),
+            );
+            renderer.set_pass_detail(false);
+        }
        views.push(json!({
            "yaw_offset": offset,
            "gpu_ms": summary(&gpu),
@@ -417,6 +441,9 @@ fn replay(window: Arc<Window>) -> Result<(), Box<dyn std::error::Error>> {
            // indices hidden.
            "culled": renderer.culled_sections(),
        }));
+        if let Some(Value::Object(view)) = views.last_mut() {
+            view.extend(detail);
+        }
    }
    let section_draws = if renderer.flat_draws() {
        "flat"
@@ -424,6 +451,11 @@ fn replay(window: Arc<Window>) -> Result<(), Box<dyn std::error::Error>> {
        "indirect"
    };
    let memory = o.memory.then(|| memory_report(&renderer));
+    let gpu_detail = o
+        .gpu_detail
+        .then(|| renderer.pass_detail_support())
+        .flatten()
+        .map(pack_timing::support_json);
    let report = json!({
        "capture": o.dir.display().to_string(),
        "adapter": renderer.info.name,
@@ -454,6 +486,7 @@ fn replay(window: Arc<Window>) -> Result<(), Box<dyn std::error::Error>> {
        "notes": notes,
        "views": views,
        "memory": memory,
+        "gpu_detail": gpu_detail,
    });
    println!("{}", serde_json::to_string_pretty(&report)?);
    Ok(())
@@ -1442,6 +1442,8 @@ impl Audio {
        } else {
            Err("no output on a dedicated server".into())
        };
+        // Without `audio` a stream can't exist (`Infallible`), so the `Ok` arm never runs.
+        #[cfg_attr(not(feature = "audio"), allow(unreachable_code))]
        let (stream, live) = match opened {
            Ok(v) => (Some(v), true),
            Err(e) => {
@@ -1279,6 +1279,9 @@ pub struct ChatScreen {
    /// `CommandSuggestions.setRestrictions`: what the Chat option allows.
    pub abilities: ChatAbilities,
    pub layout: SuggestLayout,
+    /// `MouseHandler.lastClick`: a click within 250 ms of the last one on
+    /// this screen is a double click.
+    last_click: Option<std::time::Instant>,
 }
 /// Local completions waiting for the server's reply to request `id`.
 struct Awaiting {
@@ -1401,6 +1404,7 @@ impl ChatScreen {
            auto_suggestions: true,
            abilities,
            layout: SuggestLayout::CHAT,
+            last_click: None,
        };
        s.update_command_info(m, c);
        s
@@ -1439,6 +1443,7 @@ impl ChatScreen {
            auto_suggestions: true,
            abilities: ChatAbilities::new(ChatVisibility::Full),
            layout: SuggestLayout::COMMAND_BLOCK,
+            last_click: None,
        };
        s.update_command_info(m, c);
        s
@@ -1966,8 +1971,15 @@ impl ChatScreen {
            }
            self.suggestions = Some(l);
        }
+        // MouseHandler: the same screen's click within 250 ms is a double
+        // click, which selects the word under the pointer.
+        let now = std::time::Instant::now();
+        let double = self
+            .last_click
+            .is_some_and(|at| now.duration_since(at).as_millis() < 250);
+        self.last_click = Some(now);
        if self.input.contains(x, y) {
-            self.input.click(m, x, false);
+            self.input.click(m, x, false, double);
            return true;
        }
        false
@@ -305,6 +305,31 @@ fn locate_coordinates_fill_chat_with_teleport_without_submitting() {
    }
 }

+/// `EditBox.onClick`: a double click selects the word under the pointer; a
+/// single click only places the caret there.
+#[test]
+fn a_double_click_in_the_chat_box_selects_the_word() {
+    let font = font();
+    let m = Measure(&font);
+    let registries = Registries::default();
+    let c = Commands {
+        dispatcher: crate::command::vanilla::game_dispatcher(),
+        registries: &registries,
+    };
+    let mut screen = ChatScreen::new(&m, &c, "", false, 0, 640, 360, full());
+    screen.type_text(&m, &c, "hello world");
+    // The pointer on the last letter: the first click places the caret there,
+    // the second takes the word.
+    let x = f64::from(screen.input.x) + f64::from(font.width("hello world")) - 1.0;
+    let y = f64::from(screen.input.y) + 2.0;
+    assert!(screen.click(&m, &c, x, y));
+    assert!((10..=11).contains(&screen.input.cursor));
+    assert_eq!(screen.input.highlight, screen.input.cursor);
+    assert!(screen.click(&m, &c, x, y));
+    assert_eq!((screen.input.highlight, screen.input.cursor), (6, 11));
+    assert_eq!(screen.input.selected_text(), "world");
+}
+
 #[test]
 fn history_arrows_recall_messages_and_restore_the_draft() {
    use winit::keyboard::KeyCode::{ArrowDown, ArrowUp};
@@ -715,6 +715,31 @@ impl Chunk {
    pub fn block(&self, x: i32, y: i32, z: i32) -> BlockStateId {
        BlockStateId(self.get(x, y, z))
    }
+    /// The blocks that `matches`, section by section from the bottom, each section's in y, z, x
+    /// order. A section whose palette holds none is skipped.
+    pub fn blocks_where(
+        &self,
+        matches: impl Fn(BlockStateId) -> bool,
+    ) -> Vec<horizon_core::position::BlockPos> {
+        let mut out = Vec::new();
+        for (s, section) in self.sections.iter().enumerate() {
+            if !section.blocks.maybe_has(|v| matches(BlockStateId(v))) {
+                continue;
+            }
+            let base = self.min_y + 16 * s as i32;
+            for y in base..base + 16 {
+                for lz in 0..16 {
+                    for lx in 0..16 {
+                        let (wx, wz) = (self.x * 16 + lx, self.z * 16 + lz);
+                        if matches(self.block(wx, y, wz)) {
+                            out.push(horizon_core::position::BlockPos::new(wx, y, wz));
+                        }
+                    }
+                }
+            }
+        }
+        out
+    }
    /// The highest y where `matches`, scanning down. Sections holding only
    /// `skip` are passed over whole: `matches` must be false for it.
    pub fn highest(&self, skip: u32, mut matches: impl FnMut(i32) -> bool) -> Option<i32> {
@@ -413,12 +413,20 @@ pub enum NameOrId {
 pub struct Crafter {
    pub items: [Option<ItemStack>; 9],
    pub disabled: [bool; 9],
-    pub triggered: bool,
+    /// `containerData` slot 9 as saved (`triggered`): any int, triggered
+    /// only at 1 ([`Crafter::is_triggered`]).
+    pub triggered: i32,
    pub crafting_ticks: i32,
    /// The block state's `triggered` when last ticked (not saved): the block
    /// entity flag follows it only when it changes (`CrafterBlock.neighborChanged`).
    pub state_triggered: Option<bool>,
 }
+impl Crafter {
+    /// `CrafterBlockEntity.isTriggered`: `containerData.get(9) == 1`.
+    pub fn is_triggered(&self) -> bool {
+        self.triggered == 1
+    }
+}
 #[derive(Clone, Debug, Default)]
 pub struct Banner {
    pub layers: Vec<BannerLayer>,
@@ -465,6 +473,9 @@ pub struct Jukebox {
    /// reference exists. Keep this separate from legacy playback adoption.
    pub song_clock_present: bool,
    pub playing: bool,
+    /// A clock a save brought back, not playing yet: `setSongWithoutPlaying`
+    /// keeps the song and its clock without the sound's level event 1010.
+    pub loaded_clock: bool,
 }
 impl Jukebox {
    /// `JukeboxBlockEntity.getTheItem`: the disc it holds.
@@ -291,10 +291,15 @@ impl SceneCollisions<'_, '_> {
    }
    fn context(&self, bounds: Aabb) -> CollisionContext<'static> {
        let y = bounds.min_position().y;
-        if !self
-            .subject
-            .is_some_and(|s| s.lava_walker || s.leather_boots)
-        {
+        // An entity context is needed wherever PowderSnowBlock or a strider
+        // reads the entity: boots, the walkable tag, a long fall.
+        if !self.subject.is_some_and(|s| {
+            s.lava_walker
+                || s.leather_boots
+                || s.walkable_type
+                || s.falling_block
+                || s.fall_distance > 2.5
+        }) {
            return CollisionContext::position(y);
        }
        CollisionContext::for_entity(
@@ -3,7 +3,8 @@
 //! - a function with `sampler2D` parameters is copied once per set of samplers its callers pass
 //!   (all of them a shader's global samplers), the copy reading those samplers by name;
 //! - an unsized array (`const float[] w = float[](...)`, `float w[] = ...`) takes the size its
-//!   initializer gives.
+//!   initializer gives;
+//! - an array declared with a `const int`'s size takes the constant's expression.

 /// The longest shader rewritten (vanilla's, includes expanded, are a few KiB).
 const MAX_LEN: usize = 64 * 1024;
@@ -17,7 +18,115 @@ pub(super) fn fixups(text: &str) -> String {
    if text.len() > MAX_LEN {
        return text.to_owned();
    }
-    size_unsized_arrays(&specialize_sampler_params(text))
+    size_by_int_constants(&size_unsized_arrays(&specialize_sampler_params(text)))
+}
+
+/// The most `const int`s a shader's arrays are sized by.
+const MAX_INT_CONSTANTS: usize = 256;
+
+/// `type name[n]` becomes `type name[(expression)]` where `const int n = expression;` is in scope;
+/// accesses (`name[n]`) are left as they are. Two constants of one name and different values in
+/// one scope, which only exclusive `#if` branches allow, leave the text as it was; the same one
+/// twice is a guarded include pasted twice.
+fn size_by_int_constants(text: &str) -> String {
+    struct Constant<'a> {
+        name: &'a str,
+        expression: &'a str,
+        from: usize,
+        to: usize,
+    }
+    let bytes = text.as_bytes();
+    let mut constants: Vec<Constant> = Vec::new();
+    let mut scopes: Vec<Vec<usize>> = vec![Vec::new()];
+    let mut i = 0;
+    while i < bytes.len() {
+        match bytes[i] {
+            b'{' => scopes.push(Vec::new()),
+            b'}' => {
+                for c in scopes.pop().unwrap_or_default() {
+                    constants[c].to = i;
+                }
+                if scopes.is_empty() {
+                    return text.to_owned();
+                }
+            }
+            b'c' if text[i..].starts_with("const int ")
+                && (i == 0 || !is_ident(char::from(bytes[i - 1]))) =>
+            {
+                let start = i + "const int ".len();
+                let Some(end) = text[start..].find([';', '{', '}']).map(|e| start + e) else {
+                    break;
+                };
+                if bytes[end] == b';'
+                    && let Some((name, expression)) = text[start..end].split_once('=')
+                {
+                    let (name, expression) = (name.trim(), expression.trim());
+                    if is_name(name) && !expression.is_empty() {
+                        let scope = scopes.last_mut().expect("the global scope stays");
+                        let same = scope.iter().find(|&&c| constants[c].name == name);
+                        match same {
+                            Some(&c) if constants[c].expression == expression => {}
+                            Some(_) => return text.to_owned(),
+                            None if constants.len() == MAX_INT_CONSTANTS => {
+                                return text.to_owned();
+                            }
+                            None => {
+                                scope.push(constants.len());
+                                constants.push(Constant {
+                                    name,
+                                    expression,
+                                    from: end,
+                                    to: text.len(),
+                                });
+                            }
+                        }
+                    }
+                }
+                i = end;
+                continue;
+            }
+            _ => {}
+        }
+        i += 1;
+    }
+    if constants.is_empty() {
+        return text.to_owned();
+    }
+    let mut out = String::with_capacity(text.len());
+    let mut copied = 0;
+    let mut at = 0;
+    while let Some(found) = text[at..].find('[') {
+        let open = at + found;
+        at = open + 1;
+        let Some(close) = text[open..].find(']').map(|c| open + c) else {
+            break;
+        };
+        let size = text[open + 1..close].trim();
+        let Some(constant) = constants
+            .iter()
+            .filter(|c| c.name == size && c.from < open && open < c.to)
+            .max_by_key(|c| c.from)
+        else {
+            continue;
+        };
+        if !declares_an_array(text, open) {
+            continue;
+        }
+        out.push_str(&text[copied..=open]);
+        out.push('(');
+        out.push_str(constant.expression);
+        out.push(')');
+        copied = close;
+    }
+    out.push_str(&text[copied..]);
+    out
+}
+
+/// Whether the `[` at `open` follows `type name`, so it sizes a declaration.
+fn declares_an_array(text: &str, open: usize) -> bool {
+    ident_before(text, open)
+        .and_then(|(start, _)| ident_before(text, start))
+        .is_some_and(|(_, ty)| !matches!(ty, "return" | "else" | "case"))
 }

 fn is_ident(c: char) -> bool {
@@ -245,6 +245,72 @@ fn thousands_of_calls_are_left_as_they_were() {
    );
 }

+#[test]
+fn an_array_sized_by_a_local_int_constant_takes_its_expression() {
+    let text =
+        "void main() {\n    const int n = COUNT / 4;\n    vec4 s[n];\n    s[0] = vec4(n);\n}\n";
+    let out = size_by_int_constants(text);
+    assert!(out.contains("vec4 s[(COUNT / 4)];"), "{out}");
+    assert!(out.contains("s[0] = vec4(n);"), "{out}");
+}
+
+#[test]
+fn each_function_sizes_by_its_own_constant_and_accesses_are_kept() {
+    let text = "float f() {\n    const int n = 2;\n    float a[n];\n    a[1] = 1.0;\n    return a[n - 1];\n}\n\
+        float g() {\n    const int n = 4;\n    float b[n];\n    b[3] = 1.0;\n    float c = b[n];\n    return c;\n}\n";
+    let out = size_by_int_constants(text);
+    assert!(out.contains("float a[(2)];"), "{out}");
+    assert!(out.contains("float b[(4)];"), "{out}");
+    assert!(out.contains("b[3] = 1.0;"), "{out}");
+    assert!(out.contains("float c = b[n];"), "{out}");
+    assert!(out.contains("return a[n - 1];"), "{out}");
+}
+
+#[test]
+fn an_inner_constant_shadows_the_outer_one_only_inside_its_block() {
+    let text = "void main() {\n    const int n = 2;\n    {\n        const int n = 4;\n        float inner[n];\n    }\n\
+        float outer[n];\n}\n";
+    let out = size_by_int_constants(text);
+    assert!(out.contains("float inner[(4)];"), "{out}");
+    assert!(out.contains("float outer[(2)];"), "{out}");
+}
+
+#[test]
+fn constants_of_exclusive_branches_leave_the_text_as_it_was() {
+    let text = "void main() {\n#ifdef A\n    const int n = 2;\n#else\n    const int n = 4;\n#endif\n    float a[n];\n}\n";
+    assert_eq!(size_by_int_constants(text), text);
+}
+
+#[test]
+fn a_guarded_include_pasted_twice_still_sizes_its_arrays() {
+    let include = "#ifndef I\n#define I\nconst int bins = 2;\n#endif\n";
+    let text = format!("{include}{include}void main() {{\n    float a[bins];\n}}\n");
+    assert!(size_by_int_constants(&text).contains("float a[(2)];"));
+}
+
+#[test]
+fn arrays_sized_by_two_functions_constants_translate_to_their_own_sizes() {
+    let fsh = "#version 330\nout vec4 fragColor;\n\
+        float f() {\n    const int n = 2;\n    float a[n];\n    a[1] = 1.0;\n    return a[1];\n}\n\
+        float g() {\n    const int n = 4;\n    float b[n];\n    b[3] = 1.0;\n    return b[3];\n}\n\
+        void main() {\n    fragColor = vec4(f() + g());\n}\n";
+    let program = translate(fsh).unwrap();
+    let mut sizes: Vec<u32> = program
+        .fragment
+        .types
+        .iter()
+        .filter_map(|(_, ty)| match ty.inner {
+            naga::TypeInner::Array {
+                size: naga::ArraySize::Constant(n),
+                ..
+            } => Some(n.get()),
+            _ => None,
+        })
+        .collect();
+    sizes.sort_unstable();
+    assert_eq!(sizes, [2, 4]);
+}
+
 #[test]
 fn unsized_arrays_take_their_initializers_size() {
    let text = "const float[] w = float[](0.25, 0.5, 0.25);\n\
@@ -36,7 +36,7 @@ struct Globals {
    // w: apply the no-pack HDR gain; HDR_WRITE_LIGHT independently keeps float alpha as coverage.
    hdr_light: vec4<f32>,
    hdr_settings: vec4<f32>,
-    hdr_shares: vec4<f32>,
+    hdr_gains: vec4<f32>,
 }
@group(0) @binding(0) var<uniform> globals: Globals;
@group(0) @binding(1) var atlas: texture_2d<f32>;
@@ -292,7 +292,7 @@ fn entity_written_color(in: Out, color: vec4<f32>) -> vec4<f32> {
    if HDR_WRITE_LIGHT && globals.hdr_light.w != 0.0 && in.overlay != 11u && in.overlay != 12u {
        var mark = hdr_entity_mark(in);
        if in.overlay == 4u { mark = hdr_scene_alpha(globals.hdr_light.y); }
-        return vec4(hdr_written(color.rgb, mark, globals.hdr_settings, globals.hdr_shares), color.a);
+        return vec4(hdr_written(color.rgb, mark, globals.hdr_settings, globals.hdr_gains), color.a);
    }
    if FRAME_LINEAR && (in.overlay == 11u || in.overlay == 12u) {
        // The cracks scale what is under them by twice their colour (CRUMBLING_BLEND). Vanilla's
@@ -451,7 +451,7 @@ fn celestial_color(in: Out) -> vec4<f32> {
@fragment fn fs_celestial(in: Out) -> @location(0) vec4<f32> {
    let color = celestial_color(in);
    if HDR_WRITE_LIGHT && globals.hdr_light.w != 0.0 {
-        return vec4(hdr_written(color.rgb, hdr_entity_mark(in), globals.hdr_settings, globals.hdr_shares), color.a);
+        return vec4(hdr_written(color.rgb, hdr_entity_mark(in), globals.hdr_settings, globals.hdr_gains), color.a);
    }
    return frame_stored(color);
 }
@@ -472,7 +472,7 @@ fn celestial_color(in: Out) -> vec4<f32> {
    // or it would come out darker than the sky around it.
    let full = y >= globals.hdr_windows[1][clamp(tier, 1u, 4u) - 1u];
    if HDR_WRITE_LIGHT && globals.hdr_light.w != 0.0 {
-        return vec4(hdr_written(added, select(1.0, hdr_mark(tier, y), full), globals.hdr_settings, globals.hdr_shares), color.a);
+        return vec4(hdr_written(added, select(1.0, hdr_mark(tier, y), full), globals.hdr_settings, globals.hdr_gains), color.a);
    }
    // Premultiplied after the decode: the light the texel adds, at its coverage.
    if HDR_WRITE_LIGHT { return vec4(frame_stored(color).rgb * color.a, color.a); }
@@ -192,6 +192,7 @@ fn packed_wanted() -> bool {
 pub(crate) mod animate;
 mod arena;
 pub mod capture;
+mod census;
 pub mod compositor;
 pub(crate) mod core_lines;
 pub(crate) mod core_sky;
@@ -209,6 +210,7 @@ mod hdr_icc;
 mod hdr_start;
 mod hdr_stats;
 pub(crate) mod hud_coverage;
+mod in_flight;
 pub use hdr::{Calibration as HdrCalibration, Output as HdrOutput};
 mod hold;
 pub use hold::WorldHold;
@@ -246,9 +248,11 @@ mod pack_post;
 mod pack_shadow;
 mod pack_sky;
 mod pack_textures;
-pub(crate) mod pack_timing;
+pub mod pack_timing;
 pub mod pack_uniforms;
 mod pack_weather;
+mod pass_timing_api;
+use pass_timing_api::{after_culling_pass, pixel_count, world_pass_after_culling};
 mod page_runs;
 pub mod panorama;
 mod readback;
@@ -337,42 +341,6 @@ fn surface_pass<'e>(
        ..Default::default()
    })
 }
-fn world_pass_after_culling<'e>(
-    encoder: &'e mut wgpu::CommandEncoder,
-    view: &wgpu::TextureView,
-    depth: &wgpu::TextureView,
-    keep_depth: bool,
-    timing: Option<&mut pack_timing::PassTiming>,
-    name: &str,
-) -> wgpu::RenderPass<'e> {
-    encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
-        label: Some("Horizon world, after culling"),
-        timestamp_writes: timing.and_then(|t| t.writes(name)),
-        color_attachments: &[Some(wgpu::RenderPassColorAttachment {
-            view,
-            resolve_target: None,
-            depth_slice: None,
-            ops: wgpu::Operations {
-                load: wgpu::LoadOp::Load,
-                store: wgpu::StoreOp::Store,
-            },
-        })],
-        depth_stencil_attachment: Some(wgpu::RenderPassDepthStencilAttachment {
-            view: depth,
-            depth_ops: Some(wgpu::Operations {
-                load: wgpu::LoadOp::Load,
-                // A shader pack reads it as depthtex0.
-                store: if keep_depth {
-                    wgpu::StoreOp::Store
-                } else {
-                    wgpu::StoreOp::Discard
-                },
-            }),
-            stencil_ops: None,
-        }),
-        ..Default::default()
-    })
-}
 /// The point a `shaders/` pack's terrain is drawn relative to: the camera with the fraction of
 /// each coordinate rounded to the nearest 1/65536 block. Read back with a probe pack of ours,
 /// Iris 1.11.7's terrain `gl_Vertex` is the block's position minus this, for cameras from 13
@@ -427,10 +395,10 @@ struct Globals {
    /// full (`hdr::Hdr::windows`); zero without HDR.
    hdr_windows: [[f32; 4]; 2],
    hdr_light: [f32; 4],
-    /// Headroom, effective scene gain, world/look and debug, as HDR output's pass has them
+    /// The scene's peak, HDR lighting's gain, world/look and debug; then the tiers' gains
    /// (`Hdr::draw_params`).
    hdr_settings: [f32; 4],
-    hdr_shares: [f32; 4],
+    hdr_gains: [f32; 4],
 }
 #[repr(C)]
 #[derive(Clone, Copy, bytemuck::Pod, bytemuck::Zeroable)]
@@ -1473,10 +1441,14 @@ pub struct Renderer {
    pack_loading: Option<PackLoading>,
    /// The post passes of one of Horizon's own shader packs; never beside `pack_post`'s.
    native: Option<native_pack::NativePack>,
-    /// Time the shader pack's passes on the GPU (F3, or `HORIZON_SHADER_PACK_TIMING`).
+    /// Time the shader pack's passes on the GPU (F3, or a capture made with `--gpu`).
    pass_timing: bool,
+    /// Times the parts of passes too (`set_pass_detail`).
+    pass_detail: bool,
    /// Least time between timed frames (`set_pass_timing_gap`).
    pass_timing_gap: std::time::Duration,
+    /// Whether the timers keep every timed frame for `take_timed_frames`.
+    keep_timed_frames: bool,
    /// Times Horizon's own passes on the GPU, as `pass_timing` does (`own_pass_times`).
    own_timing: Option<pack_timing::PassTiming>,
    /// The entity vertices Horizon draws itself while a shader pack draws the others.
@@ -2547,160 +2519,6 @@ enum FirstFrame {
 fn on_off(on: bool) -> &'static str {
    if on { "on" } else { "off" }
 }
-impl Renderer {
-    /// Sections with GPU buffers, for soak tests watching residency.
-    pub fn resident_sections(&self) -> usize {
-        self.sections.len()
-    }
-    /// Quads of the far terrain tiles with GPU buffers.
-    pub fn lod_quads(&self) -> u64 {
-        self.lods
-            .values()
-            .map(|tile| u64::from(tile.mesh.solid + tile.mesh.translucent))
-            .sum()
-    }
-    /// Tiles and quads of the far terrain tiles with GPU buffers, by level.
-    pub fn lod_levels(&self) -> Vec<[u64; 2]> {
-        let mut levels = Vec::new();
-        for (key, tile) in &self.lods {
-            let level = usize::from(key.level);
-            if levels.len() <= level {
-                levels.resize(level + 1, [0, 0]);
-            }
-            levels[level][0] += 1;
-            levels[level][1] += u64::from(tile.mesh.solid + tile.mesh.translucent);
-        }
-        levels
-    }
-    /// Whether solid quads go to the arena in the compact layout
-    /// (`packed_quads`), and whether far tiles' own records are on
-    /// (`lod::packed::far_packing`).
-    pub fn packed_layout(&self) -> [bool; 2] {
-        [self.packed_quads, crate::lod::packed::far_packing()]
-    }
-    /// Bytes of the arena the resident chunk sections hold, and of the one far
-    /// tiles hold: the same split `gpu_census` reports, for `status`, so the
-    /// compact layouts can be seen working.
-    pub fn vertex_bytes_split(&self) -> [u64; 2] {
-        let stride = std::mem::size_of::<TerrainVertex>() as u64;
-        let used = |s: &SectionGpu| (s.solid_slots + u64::from(s.translucent) * 4) * stride;
-        [
-            self.sections.values().map(used).sum(),
-            self.lods.values().map(|tile| used(&tile.mesh)).sum(),
-        ]
-    }
-    /// Bytes of the section vertex arenas' buffers, and of the vertices
-    /// resident sections hold in them.
-    pub fn section_vertex_bytes(&self) -> [u64; 2] {
-        let stride = std::mem::size_of::<TerrainVertex>() as u64;
-        let vertices: u64 = self
-            .sections
-            .values()
-            .chain(self.lods.values().map(|tile| &*tile.mesh))
-            .map(|s| s.solid_slots + u64::from(s.translucent) * 4)
-            .sum();
-        let translucent = self.translucent_arena.as_ref();
-        let arenas = self.arena.bytes() + translucent.map_or(0, arena::Arena::bytes);
-        [arenas, vertices * stride]
-    }
-    /// Bytes of the renderer's largest GPU resources, by name (`scene_replay --memory`):
-    /// the terrain arenas (their pages, and what resident sections and far tiles use of
-    /// them), the quad indices, the block sprites with their mips, the LabPBR maps, flat
-    /// draws' buffers and the visibility buffer's.
-    pub fn gpu_census(&self) -> Vec<(&'static str, u64)> {
-        let stride = std::mem::size_of::<TerrainVertex>() as u64;
-        let used = |s: &SectionGpu| (s.solid_slots + u64::from(s.translucent) * 4) * stride;
-        let textures = |t: &[wgpu::Texture]| t.iter().map(texture_bytes).sum::<u64>();
-        let translucent = self.translucent_arena.as_ref();
-        vec![
-            ("section_arena_pages", self.arena.bytes()),
-            (
-                "translucent_arena_pages",
-                translucent.map_or(0, arena::Arena::bytes),
-            ),
-            ("sorted_index_pages", self.sorted_indices.bytes()),
-            (
-                "near_section_vertices",
-                self.sections.values().map(used).sum(),
-            ),
-            (
-                "held_section_vertices",
-                self.hold
-                    .sections()
-                    .filter_map(|held| held.gpu.as_ref())
-                    .map(used)
-                    .sum(),
-            ),
-            (
-                "far_tile_vertices",
-                self.lods.values().map(|tile| used(&tile.mesh)).sum(),
-            ),
-            ("quad_indices", self.indices.size()),
-            ("block_sprites", textures(&self.sprite_textures)),
-            (
-                "pbr_maps",
-                self.pbr_maps
-                    .as_ref()
-                    .map_or(0, |maps| maps.iter().flatten().map(texture_bytes).sum()),
-            ),
-            (
-                "flat_draws",
-                self.flat.as_ref().map_or(0, flat::Flat::bytes),
-            ),
-            (
-                "visibility_buffer",
-                self.visbuf.as_ref().map_or(0, visbuffer::Visbuffer::bytes),
-            ),
-        ]
-    }
-    /// Device memory the backend's allocator holds, by the label of what holds
-    /// it, largest first, with its allocated and reserved totals (Vulkan and
-    /// DirectX 12; none on Metal and OpenGL) (`horizon-ctl memory`).
-    pub fn gpu_memory_by_label(&self) -> Option<(u64, u64, Vec<(String, u64)>)> {
-        let report = self.device.generate_allocator_report()?;
-        let mut by_label: HashMap<String, u64> = HashMap::new();
-        for a in report.allocations {
-            *by_label.entry(a.name).or_default() += a.size;
-        }
-        let mut labels: Vec<_> = by_label.into_iter().collect();
-        labels.sort_by(|a, b| b.1.cmp(&a.1).then_with(|| a.0.cmp(&b.0)));
-        Some((
-            report.total_allocated_bytes,
-            report.total_reserved_bytes,
-            labels,
-        ))
-    }
-    /// Heap bytes of the renderer's per-section bookkeeping (`horizon-ctl memory`):
-    /// resident sections, far tiles, block entities and light sources by section.
-    pub fn cpu_census(&self) -> [(&'static str, usize); 4] {
-        use std::mem::size_of;
-        let per_section = |map_len: usize, lists: usize| {
-            map_len * (size_of::<SectionKey>() + size_of::<Vec<([i32; 3], u32)>>() + 1)
-                + lists * size_of::<([i32; 3], u32)>()
-        };
-        let lists = |map: &crate::fast_hash::FxHashMap<SectionKey, Vec<([i32; 3], u32)>>| {
-            per_section(
-                map.capacity(),
-                map.values().map(Vec::capacity).sum::<usize>(),
-            )
-        };
-        let animated: usize = self
-            .sections
-            .values()
-            .map(|s| s.animated_layers.len() * size_of::<u16>())
-            .sum();
-        [
-            ("resident_sections", self.sections.heap_bytes() + animated),
-            (
-                "far_tiles",
-                self.lods.capacity()
-                    * (size_of::<crate::lod::TileKey>() + size_of::<lod::Tile>() + 1),
-            ),
-            ("block_entities", lists(&self.block_entities)),
-            ("light_sources", lists(&self.light_blocks)),
-        ]
-    }
-}
 impl Renderer {
    pub async fn new(
        window: Arc<Window>,
@@ -5239,8 +5057,10 @@ impl Renderer {
            pack_post: None,
            pack_loading: None,
            native: None,
-            pass_timing: pack_timing::PassTiming::logging(),
+            pass_timing: false,
+            pass_detail: false,
            pass_timing_gap: std::time::Duration::ZERO,
+            keep_timed_frames: false,
            own_timing: None,
            pack_entity_rest: Vec::new(),
            cloud_bindings,
@@ -7602,51 +7422,6 @@ impl Renderer {
                .terrain_inputs(self.pack_terrain_flat),
        )
    }
-    /// Times the shader pack's passes on the GPU while `on` (the F3 overlay is open), or always
-    /// with `HORIZON_SHADER_PACK_TIMING`.
-    pub fn set_pass_timing(&mut self, on: bool) {
-        self.pass_timing = on || pack_timing::PassTiming::logging();
-    }
-    /// Times a frame at most once per `gap` while passes are timed (the F3 overlay needs far fewer
-    /// samples than a measurement). `HORIZON_SHADER_PACK_TIMING` keeps every sample.
-    pub fn set_pass_timing_gap(&mut self, gap: std::time::Duration) {
-        self.pass_timing_gap = if pack_timing::PassTiming::logging() {
-            std::time::Duration::ZERO
-        } else {
-            gap
-        };
-    }
-    /// The running shader pack's timer, of either kind.
-    fn pass_timer<'a>(
-        pack: &'a mut Option<(i32, Option<pack_post::PackPost>)>,
-        native: &'a mut Option<native_pack::NativePack>,
-    ) -> Option<&'a mut Option<pack_timing::PassTiming>> {
-        match (pack, native) {
-            (Some((_, Some(post))), _) => Some(&mut post.timing),
-            (_, Some(native)) => Some(&mut native.timing),
-            _ => None,
-        }
-    }
-    /// Each pass of the running shader pack with its median GPU time in milliseconds, while
-    /// they are timed (`set_pass_timing`).
-    pub fn shader_pass_times(&self) -> Vec<(String, f32)> {
-        let timer = match (&self.pack_post, &self.native) {
-            (Some((_, Some(post))), _) => post.timing.as_ref(),
-            (_, Some(native)) => native.timing.as_ref(),
-            _ => None,
-        };
-        timer
-            .map(pack_timing::PassTiming::medians)
-            .unwrap_or_default()
-    }
-    /// Each of Horizon's own passes with its median GPU time in milliseconds, while they are
-    /// timed (`set_pass_timing`).
-    pub fn own_pass_times(&self) -> Vec<(String, f32)> {
-        self.own_timing
-            .as_ref()
-            .map(pack_timing::PassTiming::medians)
-            .unwrap_or_default()
-    }
    /// The macros this renderer gives shader packs: the GL extensions this device has
    /// (subgroups, when it has them), and the vendor, renderer and mipmap levels
    /// (`Macros::define_renderer`).
@@ -8255,6 +8030,8 @@ impl Renderer {
        }
        if let Some(t) = &mut self.own_timing {
            t.gap = self.pass_timing_gap;
+            t.keep_frames(self.keep_timed_frames);
+            t.set_detail(self.pass_detail);
            t.begin(&self.device, &self.queue);
        }
        if self.animated_textures {
@@ -8291,14 +8068,14 @@ impl Renderer {
            self.shader_pack_kind().is_some(),
            !frame.title,
        );
-        let (hdr_settings, hdr_shares) = self
+        let (hdr_settings, hdr_gains) = self
            .hdr
            .as_ref()
            .map_or(([0.0; 4], [0.0; 4]), |h| h.draw_params(!frame.title));
        self.world_post.baked_light(
            hdr_gain,
            hdr_settings,
-            hdr_shares,
+            hdr_gains,
            self.hdr.as_ref().map_or([[0.0; 4]; 2], hdr::Hdr::windows),
        );
        let jitter = self.world_post.jitter(
@@ -8458,7 +8235,7 @@ impl Renderer {
                f32::from(u8::from(hdr_gain)),
            ],
            hdr_settings,
-            hdr_shares,
+            hdr_gains,
        };
        self.uploads
            .buffer(&mut encoder, &self.globals, 0, bytemuck::bytes_of(&globals));
@@ -8674,6 +8451,7 @@ impl Renderer {
                    &mut self.uploads,
                    &mut encoder,
                    &input,
+                    self.own_timing.as_mut(),
                )
            });
            // A frame whose planes leave the test's integers (the camera millions of blocks
@@ -10022,6 +9800,7 @@ impl Renderer {
        }
        if let Some(Some(t)) = Self::pass_timer(&mut self.pack_post, &mut self.native) {
            t.gap = self.pass_timing_gap;
+            t.keep_frames(self.keep_timed_frames);
        }
        let pack_reads_world = pack_post || native_post;
        laps.lap("r_uploads");
@@ -10546,7 +10325,8 @@ impl Renderer {
                    store: wgpu::StoreOp::Store,
                },
            })];
-            let mut pass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
+            let world_pixels = pixel_count(world_depth);
+            let first_pass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
                label: Some("Horizon world"),
                timestamp_writes: self.own_timing.as_mut().and_then(|t| t.writes("World")),
                color_attachments: &attachments,
@@ -10566,9 +10346,16 @@ impl Renderer {
                }),
                ..Default::default()
            });
+            let mut pass = pack_timing::counted(
+                self.own_timing.as_mut(),
+                first_pass,
+                world_pixels,
+                "before translucent",
+            );
            pass.set_bind_group(0, &self.group, &[]);
            pack_frame(&mut pass);
            if frame.title || (sky_visible && (frame.skybox || frame.end_sky)) {
+                pass.stage(self.own_timing.as_mut(), "sky");
                if !frame.title && frame.skybox && !pack_draws_sky && !native_sky_pass {
                    match self
                        .native
@@ -10655,16 +10442,15 @@ impl Renderer {
                        .forget_lifetime();
                    pass.set_bind_group(0, &self.group, &[]);
                    pack_frame(&mut pass);
-                    pass
+                    pack_timing::CountedPass::plain(pass)
                };
            // The occlusion test's pipeline draws into the world's colour alone.
            let plain_pass = |encoder: &mut wgpu::CommandEncoder| {
-                let mut pass =
-                    world_pass_after_culling(encoder, world_view, world_depth, true, None, "")
-                        .forget_lifetime();
+                let mut pass = after_culling_pass(encoder, world_view, world_depth, true, None)
+                    .forget_lifetime();
                pass.set_bind_group(0, &self.group, &[]);
                pack_frame(&mut pass);
-                pass
+                pack_timing::CountedPass::plain(pass)
            };
            if let Some(surface) = &surface {
                drop(pass);
@@ -10718,6 +10504,7 @@ impl Renderer {
                        keep_depth,
                        self.own_timing.as_mut(),
                        "World after visibility buffer",
+                        world_pixels,
                    );
                    pass.set_bind_group(0, &self.group, &[]);
                    pack_frame(&mut pass);
@@ -10750,6 +10537,7 @@ impl Renderer {
                            flat.draw(pass, &flat.calls[calls.clone()], vertices);
                        }
                    };
+                    pass.stage(self.own_timing.as_mut(), "solid terrain");
                    match cull {
                        // As below: phase 1, the test, then phase 2's draws
                        // that the test saw, copied after it.
@@ -10759,6 +10547,8 @@ impl Renderer {
                                drop(pass);
                                pass = plain_pass(&mut encoder);
                            }
+                            pass.split(self.own_timing.as_mut(), "occlusion boxes");
+                            pass.stage(self.own_timing.as_mut(), "occlusion boxes");
                            cull.test(&mut pass);
                            drop(pass);
                            cull.test_pass(&mut encoder, self.own_timing.as_mut());
@@ -10772,10 +10562,12 @@ impl Renderer {
                                    keep_depth,
                                    self.own_timing.as_mut(),
                                    "World after culling",
+                                    world_pixels,
                                ),
                            };
                            pass.set_bind_group(0, &self.group, &[]);
                            pack_frame(&mut pass);
+                            pass.stage(self.own_timing.as_mut(), "solid terrain phase 2");
                            for (pipeline, _, calls) in passes {
                                pass.set_pipeline(pipeline);
                                flat.draw_phase2(&mut pass, calls.clone(), vertices);
@@ -10813,6 +10605,7 @@ impl Renderer {
                    let pulled = material.is_none() && self.flat.is_some();
                    pass.set_index_buffer(self.indices.slice(..), wgpu::IndexFormat::Uint32);
                    pass.set_vertex_buffer(1, self.instances.slice(..));
+                    pass.stage(self.own_timing.as_mut(), "solid terrain");
                    if let Some(group) = warp_group {
                        pass.set_bind_group(2, group, &[]);
                    }
@@ -10837,6 +10630,8 @@ impl Renderer {
                                drop(pass);
                                pass = plain_pass(&mut encoder);
                            }
+                            pass.split(self.own_timing.as_mut(), "occlusion boxes");
+                            pass.stage(self.own_timing.as_mut(), "occlusion boxes");
                            cull.test(&mut pass);
                            drop(pass);
                            cull.test_pass(&mut encoder, self.own_timing.as_mut());
@@ -10849,6 +10644,7 @@ impl Renderer {
                                    keep_depth,
                                    self.own_timing.as_mut(),
                                    "World after culling",
+                                    world_pixels,
                                ),
                            };
                            pass.set_bind_group(0, &self.group, &[]);
@@ -10858,6 +10654,7 @@ impl Renderer {
                                wgpu::IndexFormat::Uint32,
                            );
                            pass.set_vertex_buffer(1, self.instances.slice(..));
+                            pass.stage(self.own_timing.as_mut(), "solid terrain phase 2");
                            for (pipeline, _, draws) in passes {
                                pass.set_pipeline(pipeline);
                                self.draw_sections_from(
@@ -10905,6 +10702,8 @@ impl Renderer {
                                    drop(pass);
                                    pass = plain_pass(&mut encoder);
                                }
+                                pass.split(self.own_timing.as_mut(), "occlusion boxes");
+                                pass.stage(self.own_timing.as_mut(), "occlusion boxes");
                                gpu.test(&mut pass);
                                drop(pass);
                                gpu.compact(&mut encoder, self.own_timing.as_mut());
@@ -10917,6 +10716,7 @@ impl Renderer {
                                        keep_depth,
                                        self.own_timing.as_mut(),
                                        "World after culling",
+                                        world_pixels,
                                    ),
                                };
                                pass.set_bind_group(0, &self.group, &[]);
@@ -10925,6 +10725,7 @@ impl Renderer {
                                    self.indices.slice(..),
                                    wgpu::IndexFormat::Uint32,
                                );
+                                pass.stage(self.own_timing.as_mut(), "solid terrain phase 2");
                                for (pipeline, draws, _) in passes {
                                    pass.set_pipeline(pipeline);
                                    gpu.draw(&mut pass, &self.arena, page_group, 1);
@@ -10951,6 +10752,7 @@ impl Renderer {
                && let Some(d) = &n.displacement
                && let Some(pipeline) = n.material.as_ref().and_then(|m| m.displaced.as_ref())
            {
+                pass.stage(self.own_timing.as_mut(), "displacement");
                pass.set_bind_group(0, &self.group, &[]);
                pack_frame(&mut pass);
                d.draw(&mut pass, &d.view, pipeline);
@@ -10967,6 +10769,7 @@ impl Renderer {
            let hdr_entity_mark =
                warped.map_or(&self.hdr_entity_mark_pipeline, |w| &w.hdr_entity_mark);
            if static_entity_quads > 0 {
+                pass.stage(self.own_timing.as_mut(), "static block entities");
                pass.set_pipeline(
                    warped.map_or(&self.static_entity_pipeline, |w| &w.static_entities),
                );
@@ -10992,6 +10795,7 @@ impl Renderer {
            }
            pass.set_index_buffer(self.indices.slice(..), wgpu::IndexFormat::Uint32);
            if entity_quads > 0 {
+                pass.stage(self.own_timing.as_mut(), "entities");
                pass.set_pipeline(warped.map_or(&self.entity_pipeline, |w| &w.entities));
                pass.set_bind_group(0, &self.entity_group, &[]);
                pass.set_vertex_buffer(0, self.entity_buffer.slice(..));
@@ -11003,6 +10807,7 @@ impl Renderer {
                pass.set_bind_group(0, &self.group, &[]);
            }
            if text_quads > 0 && !oit_on {
+                pass.stage(self.own_timing.as_mut(), "entity text");
                pass.set_pipeline(warped.map_or(&self.text_polygon_offset_pipeline, |w| &w.text));
                self.bind_world_text(&mut pass, warped.is_none(), false);
                pass.set_vertex_buffer(0, self.entity_buffer.slice(..));
@@ -11012,6 +10817,7 @@ impl Renderer {
            // FeatureRenderDispatcher.PreparedFrame.executeTranslucent: the shadows
            // come before the translucent items, which then cover them (#7026).
            if shadow_quads > 0 && !oit_on {
+                pass.stage(self.own_timing.as_mut(), "shadows");
                pass.set_pipeline(warped.map_or(&self.shadow_blob_pipeline, |w| &w.entity_shadows));
                pass.set_bind_group(0, &self.entity_group, &[]);
                pass.set_vertex_buffer(0, self.entity_buffer.slice(..));
@@ -11027,6 +10833,7 @@ impl Renderer {
                pass.set_bind_group(0, &self.group, &[]);
            }
            if translucent_item_quads > 0 && !oit_on {
+                pass.stage(self.own_timing.as_mut(), "translucent items");
                pass.set_pipeline(
                    warped.map_or(&self.translucent_item_pipeline, |w| &w.translucent_items),
                );
@@ -11062,6 +10869,7 @@ impl Renderer {
            .enumerate()
            {
                if count > 0 {
+                    pass.stage(self.own_timing.as_mut(), "terrain models");
                    pass.set_pipeline(&self.terrain_model_pipelines[i]);
                    pass.set_bind_group(
                        0,
@@ -11082,6 +10890,7 @@ impl Renderer {
            // translucent material, before terrain transparency. This material
            // always writes depth and never joins the improved-transparency queues.
            if fluid_quads > 0 {
+                pass.stage(self.own_timing.as_mut(), "fluid block entities");
                pass.set_pipeline(&self.fluid_pipeline);
                pass.set_bind_group(0, &self.fluid_group, &[]);
                pass.set_vertex_buffer(0, self.entity_buffer.slice(..));
@@ -11094,6 +10903,7 @@ impl Renderer {
            }
            // Cracks multiply the existing light; scalar OIT coverage cannot carry that factor.
            if crumbling_quads > 0 && (!oit_on || hdr_gain) {
+                pass.stage(self.own_timing.as_mut(), "block breaking");
                pass.set_pipeline(&self.crumbling_pipeline);
                pass.set_bind_group(0, &self.entity_group, &[]);
                pass.set_vertex_buffer(0, self.entity_buffer.slice(..));
@@ -11107,6 +10917,7 @@ impl Renderer {
            // BoatRenderer's water patch (RenderTypes.waterMask): depth only,
            // before translucent terrain, so no water shows inside the boat.
            if water_mask_quads > 0 && !oit_on {
+                pass.stage(self.own_timing.as_mut(), "boat water mask");
                pass.set_pipeline(&self.water_mask_pipeline);
                pass.set_bind_group(0, &self.entity_group, &[]);
                pass.set_vertex_buffer(0, self.entity_buffer.slice(..));
@@ -11119,6 +10930,7 @@ impl Renderer {
                pass.set_bind_group(0, &self.group, &[]);
            }
            if !frame.lightning.bolts.is_empty() && !oit_on {
+                pass.stage(self.own_timing.as_mut(), "lightning");
                pass.set_pipeline(&self.lightning_pipeline);
                pass.set_bind_group(0, &self.entity_group, &[]);
                self.lightning.draw(&mut pass, &frame.lightning);
@@ -11129,6 +10941,7 @@ impl Renderer {
                pass.set_bind_group(0, &self.group, &[]);
            }
            if swirl_quads > 0 && !oit_on {
+                pass.stage(self.own_timing.as_mut(), "energy swirl");
                pass.set_pipeline(&self.energy_swirl_pipeline);
                pass.set_bind_group(0, &self.entity_group, &[]);
                pass.set_vertex_buffer(0, self.entity_buffer.slice(..));
@@ -11145,6 +10958,7 @@ impl Renderer {
                pass.set_bind_group(0, &self.group, &[]);
            }
            if additive_quads > 0 && !oit_on {
+                pass.stage(self.own_timing.as_mut(), "additive entities");
                pass.set_bind_group(0, &self.entity_group, &[]);
                pass.set_vertex_buffer(0, self.entity_buffer.slice(..));
                let mut first = 0;
@@ -11170,20 +10984,24 @@ impl Renderer {
                pass.set_bind_group(0, &self.group, &[]);
            }
            if outline_edges > 0 && !frame.outline_after_terrain && !pack_draws_outline {
+                pass.stage(self.own_timing.as_mut(), "block outline");
                self.draw_outline(&mut pass, outline_edges as u32, frame.outline_high_contrast);
            }
            // DrawableGizmoPrimitives' opaque group writes depth, the translucent one does not.
            if debug_opaque > 0 {
+                pass.stage(self.own_timing.as_mut(), "debug lines");
                pass.set_pipeline(&self.debug_lines_opaque);
                pass.set_vertex_buffer(0, self.debug_line_buffer.slice(..));
                pass.draw(0..4, 0..debug_opaque);
            }
            if debug_depth > debug_opaque {
+                pass.stage(self.own_timing.as_mut(), "debug lines");
                pass.set_pipeline(&self.debug_lines);
                pass.set_vertex_buffer(0, self.debug_line_buffer.slice(..));
                pass.draw(0..4, debug_opaque..debug_depth);
            }
            if debug_top > 0 {
+                pass.stage(self.own_timing.as_mut(), "debug lines");
                pass.set_pipeline(&self.debug_lines_on_top);
                pass.set_vertex_buffer(0, self.debug_line_buffer.slice(..));
                pass.draw(0..4, debug_depth..debug_depth + debug_top);
@@ -11211,6 +11029,7 @@ impl Renderer {
                    keep_depth,
                    self.own_timing.as_mut(),
                    "World after copy",
+                    world_pixels,
                );
                pass.set_bind_group(0, &self.group, &[]);
                pack_frame(&mut pass);
@@ -11384,9 +11203,11 @@ impl Renderer {
                        true,
                        self.own_timing.as_mut(),
                        "World after OIT",
+                        world_pixels,
                    );
                    pass.set_bind_group(0, &self.group, &[]);
                    pass.set_index_buffer(self.indices.slice(..), wgpu::IndexFormat::Uint32);
+                    pass.stage(self.own_timing.as_mut(), "OIT marks");
                    if cloud_quads > 0 && !pack_draws_clouds {
                        self.mark_clouds(&mut pass, cloud_quads);
                    }
@@ -11419,6 +11240,8 @@ impl Renderer {
                    self.mark_translucent_terrain(&mut pass, flat, solid_draws, translucent_draws);
                }
                Some(flat) => {
+                    pass.split(self.own_timing.as_mut(), "translucent terrain");
+                    pass.stage(self.own_timing.as_mut(), "translucent terrain");
                    pass.set_pipeline(pack_flat.map_or(&flat.translucent, |p| &p.1));
                    flat.draw(
                        &mut pass,
@@ -11433,8 +11256,11 @@ impl Renderer {
                        solid_draws,
                        translucent_draws,
                    );
+                    pass.split(self.own_timing.as_mut(), "after translucent");
                }
                None => {
+                    pass.split(self.own_timing.as_mut(), "translucent terrain");
+                    pass.stage(self.own_timing.as_mut(), "translucent terrain");
                    pass.set_pipeline(translucent_pipeline);
                    if let Some(group) = warp_group {
                        pass.set_bind_group(2, group, &[]);
@@ -11457,6 +11283,7 @@ impl Renderer {
                            translucent_draws,
                        );
                    }
+                    pass.split(self.own_timing.as_mut(), "after translucent");
                }
            }
            // LevelRenderer.executeTranslucentAfterTerrain: vanilla's
@@ -11464,6 +11291,7 @@ impl Renderer {
            // the quads write depth, so before it they would hide the glass
            // or water behind them.
            if translucent_particle_quads > 0 && !oit_on {
+                pass.stage(self.own_timing.as_mut(), "translucent particles");
                pass.set_pipeline(warped.map_or(&self.entity_pipeline, |w| &w.entities));
                if let Some(group) = warp_group {
                    pass.set_bind_group(2, group, &[]);
@@ -11492,6 +11320,7 @@ impl Renderer {
            // particles (also after the OIT composite) and before the hand.
            // Its own geometry is independent of block-entity lifetime.
            if world_text_quads + world_text_offset_quads > 0 {
+                pass.stage(self.own_timing.as_mut(), "world text");
                pass.set_bind_group(0, &self.entity_group, &[]);
                pass.set_index_buffer(self.indices.slice(..), wgpu::IndexFormat::Uint32);
                pass.set_vertex_buffer(0, self.entity_buffer.slice(..));
@@ -11514,9 +11343,11 @@ impl Renderer {
            // LevelRenderer.executeClassicTransparency: translucent targets'
            // outlines follow terrain, so its blending cannot wash them out.
            if outline_edges > 0 && frame.outline_after_terrain && !pack_draws_outline {
+                pass.stage(self.own_timing.as_mut(), "block outline");
                self.draw_outline(&mut pass, outline_edges as u32, frame.outline_high_contrast);
            }
            if translucent_crumbling_quads > 0 && (!oit_on || hdr_gain) {
+                pass.stage(self.own_timing.as_mut(), "block breaking");
                pass.set_pipeline(&self.crumbling_pipeline);
                pass.set_bind_group(0, &self.entity_group, &[]);
                pass.set_vertex_buffer(0, self.entity_buffer.slice(..));
@@ -11527,6 +11358,7 @@ impl Renderer {
                );
            }
            if cloud_quads > 0 && !pack_draws_clouds && !oit_on {
+                pass.stage(self.own_timing.as_mut(), "clouds");
                pass.set_pipeline(&self.cloud_pipeline);
                pass.set_bind_group(0, &self.entity_group, &[]);
                pass.set_bind_group(1, &self.cloud_group, &[]);
@@ -11538,6 +11370,7 @@ impl Renderer {
            // terrain and clouds, so the water behind the rain is drawn first.
            pass.set_index_buffer(self.indices.slice(..), wgpu::IndexFormat::Uint32);
            if !pack_draws_weather && !oit_on {
+                pass.stage(self.own_timing.as_mut(), "weather");
                let native_weather = self
                    .native
                    .as_ref()
@@ -11549,6 +11382,7 @@ impl Renderer {
            }
            // LevelRenderer: the world border after translucent terrain and weather.
            if let Some(b) = frame.border.as_ref().filter(|_| !frame.title && !oit_on) {
+                pass.stage(self.own_timing.as_mut(), "world border");
                pass.set_pipeline(&self.border_pipeline);
                pass.set_bind_group(0, &self.border_group, &[]);
                pass.set_index_buffer(self.indices.slice(..), wgpu::IndexFormat::Uint32);
@@ -11561,6 +11395,7 @@ impl Renderer {
            }
            // LevelRenderer.executeSeeThrough, after the rest of the world.
            if see_through_quads > 0 {
+                pass.stage(self.own_timing.as_mut(), "see-through");
                pass.set_pipeline(&self.see_through_pipeline);
                self.bind_world_text(&mut pass, true, true);
                pass.set_vertex_buffer(0, self.entity_buffer.slice(..));
@@ -11573,9 +11408,11 @@ impl Renderer {
            // Native mods' primitives: after the entities and the rest of the world, into its
            // targets (its resolution, reversed depth and TAA), before the hand.
            if world_primitives {
+                pass.stage(self.own_timing.as_mut(), "mod primitives");
                self.world_primitives.draw(&mut pass);
            }
            if hand_in_world {
+                pass.stage(self.own_timing.as_mut(), "hand");
                pass.set_pipeline(&self.depth_reset);
                pass.set_bind_group(0, &self.group, &[]);
                pass.draw(0..3, 0..1);
@@ -12515,130 +12352,6 @@ pub(crate) fn copy_frame(
    );
    buffer
 }
-impl Renderer {
-    /// The frame's readbacks to start right after its submission (on the submit thread when
-    /// the frame goes there): occlusion culling's results (`cull`) and GPU culling's
-    /// statistics. GPU frames leave occlusion culling off, so a frame has one at most.
-    fn after_submit(&mut self) -> Option<submit::AfterSubmit> {
-        let cull = self.cull.as_mut().and_then(|c| c.submitted());
-        let gpu = self.gpu_culling.as_mut().and_then(|g| g.submitted());
-        match (cull, gpu) {
-            (Some(c), Some(g)) => Some(Box::new(move || {
-                c();
-                g();
-            })),
-            (Some(c), None) => Some(Box::new(c)),
-            (None, Some(g)) => Some(Box::new(g)),
-            (None, None) => None,
-        }
-    }
-    /// Frame `frame`'s statistics shown, unless a newer frame's are: a CPU frame's as it is
-    /// drawn, a GPU frame's when its counts come back (`GpuCulling::collect`).
-    fn show_stats(&mut self, frame: u64, [sections, draws, calls]: [usize; 3]) {
-        if frame > self.stats_frame {
-            self.stats_frame = frame;
-            (
-                self.drawn_sections,
-                self.section_draws,
-                self.section_draw_calls,
-            ) = (sections, draws, calls);
-        }
-    }
-    /// Frames between the last one drawn and the one whose statistics are shown: 0 after a
-    /// CPU frame, one to three in GPU frames, while their counts are on their way back.
-    pub fn stats_lag(&self) -> u64 {
-        self.frame_serial - self.stats_frame
-    }
-    /// Take in the frame the submit thread submitted: start its readbacks and, offscreen,
-    /// keep at most two frames ahead of the GPU, as a frame submitted in place does.
-    fn land_frame(&mut self) {
-        let Some(offscreen) = self.deferred.take() else {
-            return;
-        };
-        let submission = self.queue.landed();
-        if let Some(timer) = &mut self.gpu_timer {
-            timer.submitted(&self.queue);
-            timer.collect(&self.device, &mut self.gpu_times);
-        }
-        if let Some(Some(timer)) = Self::pass_timer(&mut self.pack_post, &mut self.native) {
-            timer.submitted(&self.queue);
-        }
-        if offscreen && let Some(submission) = submission {
-            self.in_flight.push_back(submission);
-            if !self.paced_elsewhere {
-                self.wait_frames();
-            }
-        }
-    }
-    /// No swapchain paces offscreen frames: keep two on the GPU at most.
-    pub fn wait_in_flight(&mut self) {
-        self.land_frame();
-        self.wait_frames();
-    }
-    /// The frame on the submit thread submitted: a surface reconfigure waits for the
-    /// device and breaks if a frame is submitted while it waits, and the compositor
-    /// copies views after them. (The end of a frame already lands the frames of the
-    /// turn before; this is the turn's own.)
-    pub fn wait_submissions(&mut self) {
-        self.queue.wait();
-    }
-    fn wait_frames(&mut self) {
-        while self.in_flight.len() > 2 {
-            let index = self.in_flight.pop_front();
-            let _ = self.device.poll(wgpu::PollType::Wait {
-                submission_index: index,
-                timeout: Some(std::time::Duration::from_secs(5)),
-            });
-        }
-    }
-    /// Take a screenshot request: queue the frame's copy, or report why the
-    /// frame cannot be read back.
-    fn take_readback(
-        &mut self,
-        request: ScreenshotRequest,
-        encoder: &mut wgpu::CommandEncoder,
-        texture: &wgpu::Texture,
-    ) -> Option<(ScreenshotRequest, wgpu::Buffer)> {
-        // The copy and PNG writer both assume 8-bit pixels; a float surface would make
-        // the row stride too small for the copy and abort in validation.
-        if self.config.format.block_copy_size(None) == Some(4) {
-            let size = [self.config.width, self.config.height];
-            let format = self.config.format.remove_srgb_suffix();
-            // The layered float frame maps the world to SDR, then adds the HUD as drawn.
-            // Other 16-bit frames keep their clipped 8-bit copy.
-            let copy = self
-                .hdr
-                .as_mut()
-                .and_then(|hdr| {
-                    hdr.sdr_screenshot(&self.device, encoder, format, request.size.is_some())
-                })
-                .or_else(|| {
-                    (texture.format() != format && texture.format() == self.output.frame.format)
-                        .then(|| {
-                            self.readback
-                                .unorm_copy(&self.device, encoder, texture, format)
-                        })
-                });
-            let texture = copy.as_ref().unwrap_or(texture);
-            Some((request, copy_frame(&self.device, encoder, texture, size)))
-        } else {
-            let error = format!(
-                "screenshots need a 32-bit surface format, not {:?}",
-                self.config.format
-            );
-            if request.background {
-                self.saved_screenshots.push(screenshot_save::Saved {
-                    path: request.path,
-                    result: Err(error),
-                    hdr: None,
-                });
-            } else {
-                self.screenshot_result = Some(Err(error));
-            }
-            None
-        }
-    }
-}
 /// `screenshots/2026-10-28_12.00.00.png` -> `screenshots/2026-10-28_12.00.00-hdr.png`.
 fn hdr_screenshot_path(path: &std::path::Path) -> PathBuf {
    let stem = path.file_stem().unwrap_or_default().to_string_lossy();
@@ -12744,56 +12457,8 @@ fn block_entities_within_reach<'a>(
        })
        .flatten()
 }
-/// Camera-relative clip planes (`Frustum`).
-#[derive(Clone, Copy, Debug)]
-pub struct Frustum {
-    planes: [Vec4; 6],
-}
-impl Frustum {
-    /// Whether the camera-relative box `min..max` is at least partly inside.
-    pub fn intersects(&self, min: Vec3, max: Vec3) -> bool {
-        !self.planes.iter().any(|p| {
-            let sign = p.truncate().cmpge(Vec3::ZERO);
-            let v = Vec3::select(sign, max, min);
-            p.truncate().dot(v) + p.w < 0.0
-        })
-    }
-    /// Whether a camera-relative sphere is at least partly inside. Frustum
-    /// planes are normalized, so each test needs only one dot product and a
-    /// radius comparison.
-    pub fn intersects_sphere(&self, center: Vec3, radius: f32) -> bool {
-        if !center.is_finite() || !radius.is_finite() || radius < 0.0 {
-            return true;
-        }
-        !self
-            .planes
-            .iter()
-            .any(|plane| plane.truncate().dot(center) + plane.w < -radius)
-    }
-    /// Depth clip planes alone: X/Y projection jitter cannot change this test.
-    /// Retaining side-of-screen geometry makes this safe before TAA selects a phase.
-    pub fn intersects_depth(&self, min: Vec3, max: Vec3) -> bool {
-        if !min.is_finite() || !max.is_finite() || !min.cmple(max).all() {
-            return true;
-        }
-        !self.planes[4..].iter().any(|p| {
-            let sign = p.truncate().cmpge(Vec3::ZERO);
-            let v = Vec3::select(sign, max, min);
-            p.truncate().dot(v) + p.w < 0.0
-        })
-    }
-    /// Whether the camera-relative box `min..max` is entirely inside. Then
-    /// `intersects` accepts every box within it: each plane's distance only
-    /// grows from this box's nearest corner to the inner box's farthest, and
-    /// rounding keeps that order.
-    pub fn contains(&self, min: Vec3, max: Vec3) -> bool {
-        self.planes.iter().all(|p| {
-            let sign = p.truncate().cmpge(Vec3::ZERO);
-            let v = Vec3::select(sign, min, max);
-            p.truncate().dot(v) + p.w >= 0.0
-        })
-    }
-}
+mod view_frustum;
+pub use view_frustum::Frustum;
 /// Vanilla's `Projection`: reversed depth (near maps to 1, far to 0, tests
 /// are GREATER_THAN_OR_EQUAL), which keeps far faces a hair apart, like
 /// fire_side's 0.01 pixel in front of its block, from z-fighting.
@@ -0,0 +1,164 @@
+//! What the renderer holds, for status, soak tests and memory reports (`horizon-ctl memory`,
+//! `scene_replay --memory`): resident sections and far tiles, and the bytes of its largest
+//! GPU resources and of its per-section bookkeeping.
+
+use std::collections::HashMap;
+
+use super::{
+    Renderer, SectionGpu, SectionKey, TerrainVertex, arena, flat, lod, texture_bytes, visbuffer,
+};
+
+impl Renderer {
+    /// Sections with GPU buffers, for soak tests watching residency.
+    pub fn resident_sections(&self) -> usize {
+        self.sections.len()
+    }
+    /// Quads of the far terrain tiles with GPU buffers.
+    pub fn lod_quads(&self) -> u64 {
+        self.lods
+            .values()
+            .map(|tile| u64::from(tile.mesh.solid + tile.mesh.translucent))
+            .sum()
+    }
+    /// Tiles and quads of the far terrain tiles with GPU buffers, by level.
+    pub fn lod_levels(&self) -> Vec<[u64; 2]> {
+        let mut levels = Vec::new();
+        for (key, tile) in &self.lods {
+            let level = usize::from(key.level);
+            if levels.len() <= level {
+                levels.resize(level + 1, [0, 0]);
+            }
+            levels[level][0] += 1;
+            levels[level][1] += u64::from(tile.mesh.solid + tile.mesh.translucent);
+        }
+        levels
+    }
+    /// Whether solid quads go to the arena in the compact layout
+    /// (`packed_quads`), and whether far tiles' own records are on
+    /// (`lod::packed::far_packing`).
+    pub fn packed_layout(&self) -> [bool; 2] {
+        [self.packed_quads, crate::lod::packed::far_packing()]
+    }
+    /// Bytes of the arena the resident chunk sections hold, and of the one far
+    /// tiles hold: the same split `gpu_census` reports, for `status`, so the
+    /// compact layouts can be seen working.
+    pub fn vertex_bytes_split(&self) -> [u64; 2] {
+        let stride = std::mem::size_of::<TerrainVertex>() as u64;
+        let used = |s: &SectionGpu| (s.solid_slots + u64::from(s.translucent) * 4) * stride;
+        [
+            self.sections.values().map(used).sum(),
+            self.lods.values().map(|tile| used(&tile.mesh)).sum(),
+        ]
+    }
+    /// Bytes of the section vertex arenas' buffers, and of the vertices
+    /// resident sections hold in them.
+    pub fn section_vertex_bytes(&self) -> [u64; 2] {
+        let stride = std::mem::size_of::<TerrainVertex>() as u64;
+        let vertices: u64 = self
+            .sections
+            .values()
+            .chain(self.lods.values().map(|tile| &*tile.mesh))
+            .map(|s| s.solid_slots + u64::from(s.translucent) * 4)
+            .sum();
+        let translucent = self.translucent_arena.as_ref();
+        let arenas = self.arena.bytes() + translucent.map_or(0, arena::Arena::bytes);
+        [arenas, vertices * stride]
+    }
+    /// Bytes of the renderer's largest GPU resources, by name (`scene_replay --memory`):
+    /// the terrain arenas (their pages, and what resident sections and far tiles use of
+    /// them), the quad indices, the block sprites with their mips, the LabPBR maps, flat
+    /// draws' buffers and the visibility buffer's.
+    pub fn gpu_census(&self) -> Vec<(&'static str, u64)> {
+        let stride = std::mem::size_of::<TerrainVertex>() as u64;
+        let used = |s: &SectionGpu| (s.solid_slots + u64::from(s.translucent) * 4) * stride;
+        let textures = |t: &[wgpu::Texture]| t.iter().map(texture_bytes).sum::<u64>();
+        let translucent = self.translucent_arena.as_ref();
+        vec![
+            ("section_arena_pages", self.arena.bytes()),
+            (
+                "translucent_arena_pages",
+                translucent.map_or(0, arena::Arena::bytes),
+            ),
+            ("sorted_index_pages", self.sorted_indices.bytes()),
+            (
+                "near_section_vertices",
+                self.sections.values().map(used).sum(),
+            ),
+            (
+                "held_section_vertices",
+                self.hold
+                    .sections()
+                    .filter_map(|held| held.gpu.as_ref())
+                    .map(used)
+                    .sum(),
+            ),
+            (
+                "far_tile_vertices",
+                self.lods.values().map(|tile| used(&tile.mesh)).sum(),
+            ),
+            ("quad_indices", self.indices.size()),
+            ("block_sprites", textures(&self.sprite_textures)),
+            (
+                "pbr_maps",
+                self.pbr_maps
+                    .as_ref()
+                    .map_or(0, |maps| maps.iter().flatten().map(texture_bytes).sum()),
+            ),
+            (
+                "flat_draws",
+                self.flat.as_ref().map_or(0, flat::Flat::bytes),
+            ),
+            (
+                "visibility_buffer",
+                self.visbuf.as_ref().map_or(0, visbuffer::Visbuffer::bytes),
+            ),
+        ]
+    }
+    /// Device memory the backend's allocator holds, by the label of what holds
+    /// it, largest first, with its allocated and reserved totals (Vulkan and
+    /// DirectX 12; none on Metal and OpenGL) (`horizon-ctl memory`).
+    pub fn gpu_memory_by_label(&self) -> Option<(u64, u64, Vec<(String, u64)>)> {
+        let report = self.device.generate_allocator_report()?;
+        let mut by_label: HashMap<String, u64> = HashMap::new();
+        for a in report.allocations {
+            *by_label.entry(a.name).or_default() += a.size;
+        }
+        let mut labels: Vec<_> = by_label.into_iter().collect();
+        labels.sort_by(|a, b| b.1.cmp(&a.1).then_with(|| a.0.cmp(&b.0)));
+        Some((
+            report.total_allocated_bytes,
+            report.total_reserved_bytes,
+            labels,
+        ))
+    }
+    /// Heap bytes of the renderer's per-section bookkeeping (`horizon-ctl memory`):
+    /// resident sections, far tiles, block entities and light sources by section.
+    pub fn cpu_census(&self) -> [(&'static str, usize); 4] {
+        use std::mem::size_of;
+        let per_section = |map_len: usize, lists: usize| {
+            map_len * (size_of::<SectionKey>() + size_of::<Vec<([i32; 3], u32)>>() + 1)
+                + lists * size_of::<([i32; 3], u32)>()
+        };
+        let lists = |map: &crate::fast_hash::FxHashMap<SectionKey, Vec<([i32; 3], u32)>>| {
+            per_section(
+                map.capacity(),
+                map.values().map(Vec::capacity).sum::<usize>(),
+            )
+        };
+        let animated: usize = self
+            .sections
+            .values()
+            .map(|s| s.animated_layers.len() * size_of::<u16>())
+            .sum();
+        [
+            ("resident_sections", self.sections.heap_bytes() + animated),
+            (
+                "far_tiles",
+                self.lods.capacity()
+                    * (size_of::<crate::lod::TileKey>() + size_of::<lod::Tile>() + 1),
+            ),
+            ("block_entities", lists(&self.block_entities)),
+            ("light_sources", lists(&self.light_blocks)),
+        ]
+    }
+}
@@ -33,7 +33,7 @@ struct Uniform {
    mode: u32,
    pad: [u32; 2],
    hdr_settings: [f32; 4],
-    hdr_shares: [f32; 4],
+    hdr_gains: [f32; 4],
    hdr_light: [f32; 4],
 }

@@ -407,7 +407,7 @@ impl CustomSky {
        self.written_gain = (globals.hdr_light[3] != 0.0).then(|| {
            let mark =
                ((1.0 - 0.24 * globals.hdr_light[1]).clamp(0.0, 1.0) * 255.0).round() / 255.0;
-            if globals.hdr_settings[2] > 0.5 && globals.hdr_settings[0] > 1.0 {
+            if globals.hdr_settings[2] > 0.5 {
                (1.0 + (globals.hdr_settings[1] - 1.0) * (1.0 - mark) / 0.24).powf(1.0 / 2.2)
            } else {
                1.0
@@ -428,7 +428,7 @@ impl CustomSky {
                mode: mode as u32,
                pad: [0; 2],
                hdr_settings: globals.hdr_settings,
-                hdr_shares: globals.hdr_shares,
+                hdr_gains: globals.hdr_gains,
                hdr_light: globals.hdr_light,
            };
            let offset = STRIDE * self.frame.len() as u64;
@@ -702,7 +702,7 @@ mod tests {
                mode: mode_index as u32,
                pad: [0; 2],
                hdr_settings: [5.0, 4.0, 1.0, f32::from(u8::from(debug))],
-                hdr_shares: [0.2, 0.5, 0.6, 1.0],
+                hdr_gains: [1.6, 2.4, 2.8, 4.0],
                hdr_light: [0.8, 0.8, 1.0, f32::from(u8::from(written))],
            };
            let buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
@@ -10,7 +10,7 @@ struct Layer {
    mode: u32,
    pad: vec2<u32>,
    hdr_settings: vec4<f32>,
-    hdr_shares: vec4<f32>,
+    hdr_gains: vec4<f32>,
    hdr_light: vec4<f32>,
 }
@group(0) @binding(0) var<uniform> layer: Layer;
@@ -54,7 +54,7 @@ fn custom_sky_color(in: Out) -> vec4<f32> {
    var color = t.rgb;
    if HDR_WRITE_LIGHT && layer.hdr_light.w != 0.0 &&
        (layer.mode == ADD || layer.mode == SUBTRACT || layer.mode == REPLACE || layer.mode == ALPHA) {
-        color = hdr_written(color, 1.0 - 0.24 * layer.hdr_light.y, layer.hdr_settings, layer.hdr_shares);
+        color = hdr_written(color, 1.0 - 0.24 * layer.hdr_light.y, layer.hdr_settings, layer.hdr_gains);
    }
    // On a frame of linear light (`FRAME_LINEAR`) the layer's colour is decoded as it is stored.
    switch layer.mode {
@@ -84,5 +84,5 @@ fn custom_sky_color(in: Out) -> vec4<f32> {

@fragment fn fs_custom_sky_screen_light(in: Out) -> @location(0) vec4<f32> {
    let color = custom_sky_color(in);
-    return vec4(hdr_written(color.rgb, 1.0 - 0.24 * layer.hdr_light.y, layer.hdr_settings, layer.hdr_shares), color.a);
+    return vec4(hdr_written(color.rgb, 1.0 - 0.24 * layer.hdr_light.y, layer.hdr_settings, layer.hdr_gains), color.a);
 }
@@ -71,7 +71,7 @@ use super::{
    Frustum, SectionKey,
    arena::{Arena, try_create},
    occlusion::Reach,
-    pack_timing::PassTiming,
+    pack_timing::{PassTiming, compute_parts},
    resident,
    submit::Queue,
    upload::Uploads,
@@ -374,6 +374,21 @@ pub(super) enum Prepared {
    OutOfMemory,
 }

+/// A part of a compute pass: `pipeline` over `[x, y]` workgroups, nothing when `x` is 0.
+fn step<'a>(
+    group: &'a wgpu::BindGroup,
+    pipeline: &'a wgpu::ComputePipeline,
+    [x, y]: [u32; 2],
+) -> impl FnMut(&mut wgpu::ComputePass<'_>) + 'a {
+    move |pass| {
+        if x > 0 {
+            pass.set_bind_group(0, group, &[]);
+            pass.set_pipeline(pipeline);
+            pass.dispatch_workgroups(x, y, 1);
+        }
+    }
+}
+
 /// The frame's `tables` before the regions, into `words`, and the parameters
 /// the frustum test and facing read with them; `None` when the CPU draws the
 /// frame (`Prepared::Cpu`): a sum of a plane's terms could leave i32
@@ -1190,12 +1205,13 @@ impl GpuCulling {
        uploads: &mut Uploads,
        encoder: &mut wgpu::CommandEncoder,
        input: &FrameInputs<'_>,
+        timing: Option<&mut PassTiming>,
    ) -> Prepared {
        self.pages.clear();
        self.ids = 0;
        self.n_updates = 0;
        self.occluding = false;
-        self.prepare_buffers(device, queue, uploads, encoder, input)
+        self.prepare_buffers(device, queue, uploads, encoder, input, timing)
            .unwrap_or(Prepared::OutOfMemory)
    }

@@ -1206,6 +1222,7 @@ impl GpuCulling {
        uploads: &mut Uploads,
        encoder: &mut wgpu::CommandEncoder,
        input: &FrameInputs<'_>,
+        mut timing: Option<&mut PassTiming>,
    ) -> Option<Prepared> {
        // Every buffer grows before anything is written. One made anew drops
        // the bind group at once, and a new section table needs every record:
@@ -1287,6 +1304,9 @@ impl GpuCulling {
                occl = OCCLUDE | if probe { PROBE } else { 0 };
            }
        }
+        let uploading = timing
+            .as_mut()
+            .and_then(|t| t.encoder_begin(encoder, "GPU culling uploads"));
        if self.records.all_dirty {
            // The whole table, after it grew or more records changed than
            // updates take (GPU culling switched on in a loaded world, a
@@ -1352,6 +1372,9 @@ impl GpuCulling {
        // are written before they are read.
        let cleared = if self.occluding { tests_at } else { phase1_end };
        encoder.clear_buffer(&self.counts.buffer, 0, Some(cleared * 4));
+        if let Some(t) = timing {
+            t.encoder_end(encoder, uploading);
+        }
        if self.group.is_none() {
            self.group = Some(self.bind(device));
            if let Some(test) = &mut self.test {
@@ -1403,23 +1426,24 @@ impl GpuCulling {
        let Some(group) = self.group.as_ref().filter(|_| self.ids > 0) else {
            return;
        };
-        let mut pass = encoder.begin_compute_pass(&wgpu::ComputePassDescriptor {
-            label: Some("GPU culling"),
-            timestamp_writes: timing.and_then(|t| t.compute_writes("GPU culling")),
-        });
-        pass.set_bind_group(0, group, &[]);
        let [apply, cull, scan, scatter] = &self.pipelines;
-        if self.n_updates > 0 {
-            pass.set_pipeline(apply);
-            pass.dispatch_workgroups(self.n_updates.div_ceil(WORKGROUP), 1, 1);
-        }
        let blocks = self.ids.div_ceil(WORKGROUP);
-        pass.set_pipeline(cull);
-        pass.dispatch_workgroups(blocks.min(ROW), blocks.div_ceil(ROW), 1);
-        pass.set_pipeline(scan);
-        pass.dispatch_workgroups(self.pass_pages, 1, 1);
-        pass.set_pipeline(scatter);
-        pass.dispatch_workgroups(blocks.min(ROW), blocks.div_ceil(ROW), 1);
+        let rows = [blocks.min(ROW), blocks.div_ceil(ROW)];
+        let updates = [self.n_updates.div_ceil(WORKGROUP), 1];
+        let (mut apply, mut cull) = (step(group, apply, updates), step(group, cull, rows));
+        let pages = [self.pass_pages, 1];
+        let (mut scan, mut scatter) = (step(group, scan, pages), step(group, scatter, rows));
+        compute_parts(
+            encoder,
+            timing,
+            "GPU culling",
+            &mut [
+                ("apply", &mut apply),
+                ("cull", &mut cull),
+                ("scan", &mut scan),
+                ("scatter", &mut scatter),
+            ],
+        );
    }

    /// The kept sections' solid draws, a count draw per page, with the quad
@@ -1494,19 +1518,22 @@ impl GpuCulling {
        if !self.occluding {
            return;
        }
-        let mut pass = encoder.begin_compute_pass(&wgpu::ComputePassDescriptor {
-            label: Some("GPU culling phase 2"),
-            timestamp_writes: timing.and_then(|t| t.compute_writes("GPU culling phase 2")),
-        });
-        pass.set_bind_group(0, group, &[]);
        let [count2, scan2, scatter2] = &test.phase2;
        let blocks = self.ids.div_ceil(WORKGROUP);
-        pass.set_pipeline(count2);
-        pass.dispatch_workgroups(blocks.min(ROW), blocks.div_ceil(ROW), 1);
-        pass.set_pipeline(scan2);
-        pass.dispatch_workgroups(self.pass_pages, 1, 1);
-        pass.set_pipeline(scatter2);
-        pass.dispatch_workgroups(blocks.min(ROW), blocks.div_ceil(ROW), 1);
+        let rows = [blocks.min(ROW), blocks.div_ceil(ROW)];
+        let pages = [self.pass_pages, 1];
+        let (mut count, mut scatter) = (step(group, count2, rows), step(group, scatter2, rows));
+        let mut scan = step(group, scan2, pages);
+        compute_parts(
+            encoder,
+            timing,
+            "GPU culling phase 2",
+            &mut [
+                ("count2", &mut count),
+                ("scan2", &mut scan),
+                ("scatter2", &mut scatter),
+            ],
+        );
    }

    /// After the frame's world passes (phase 2's counts too), in the same
@@ -2720,6 +2747,11 @@ mod tests {
        let adapter = pollster::block_on(instance.request_adapter(&Default::default())).ok()?;
        let needed =
            wgpu::Features::MULTI_DRAW_INDIRECT_COUNT | wgpu::Features::INDIRECT_FIRST_INSTANCE;
+        let timing = adapter.features()
+            & (wgpu::Features::TIMESTAMP_QUERY
+                | wgpu::Features::TIMESTAMP_QUERY_INSIDE_PASSES
+                | wgpu::Features::TIMESTAMP_QUERY_INSIDE_ENCODERS
+                | wgpu::Features::SHADER_EARLY_DEPTH_TEST);
        if !adapter.features().contains(needed)
            || super::super::flat::is_broken_intel_vulkan(&adapter.get_info())
        {
@@ -2727,7 +2759,7 @@ mod tests {
        }
        eprintln!("GPU culling on {} ({name})", adapter.get_info().name);
        pollster::block_on(adapter.request_device(&wgpu::DeviceDescriptor {
-            required_features: needed,
+            required_features: needed | timing,
            ..Default::default()
        }))
        .ok()
@@ -2834,6 +2866,11 @@ mod tests {
        // was drawn.
        let (mut eyed, mut hidden, mut several) = (0, 0, 0);
        let (mut edge, mut edge_drawn) = (None, false);
+        // Timed in detail as the renderer does: the commands, and so the draws, stay the same.
+        let mut timing = PassTiming::new(device, queue);
+        if let Some(t) = &mut timing {
+            t.set_detail(true);
+        }
        for case in 0..25 {
            let radius = [2, 5, 9][case % 3];
            let at_edge = case == 24;
@@ -2981,6 +3018,9 @@ mod tests {
                edge = Some(id);
            }
            let whole = gpu.records.all_dirty;
+            if let Some(t) = &mut timing {
+                t.begin(device, queue);
+            }
            let mut encoder = device.create_command_encoder(&Default::default());
            let input = FrameInputs {
                camera,
@@ -3000,11 +3040,18 @@ mod tests {
                    camera: camera + DVec3::Y * 2.0e7,
                    ..input
                };
-                let prepared = gpu.prepare(device, queue, &mut uploads, &mut encoder, &up);
+                let prepared = gpu.prepare(device, queue, &mut uploads, &mut encoder, &up, None);
                assert_eq!(prepared, Prepared::Cpu, "case 7");
                assert!(gpu.records.all_dirty || !gpu.records.dirty.is_empty());
            }
-            let prepared = gpu.prepare(device, queue, &mut uploads, &mut encoder, &input);
+            let prepared = gpu.prepare(
+                device,
+                queue,
+                &mut uploads,
+                &mut encoder,
+                &input,
+                timing.as_mut(),
+            );
            assert_eq!(prepared, Prepared::Gpu, "case {case}");
            match case {
                4 => assert!(
@@ -3060,12 +3107,15 @@ mod tests {
                    culled += 1;
                }
            }
-            gpu.dispatch(&mut encoder, None);
+            gpu.dispatch(&mut encoder, timing.as_mut());
            // Its statistics come back with a CPU part of the case's own.
            let cpu = [case * 7, case * 3, case];
            gpu.copy_stats(&mut encoder, case as u64, cpu);
            uploads.finish(&encoder);
            queue.submit([encoder.finish()]);
+            if let Some(t) = &mut timing {
+                t.submitted(queue);
+            }
            gpu.submitted().expect("a readback free")();
            let pages = u64::from(gpu.pass_pages);
            let counts = read(device, queue, &gpu.counts.buffer, (STATS + pages) * 4);
@@ -3124,6 +3174,18 @@ mod tests {
            "of {eyed} from an eye, {hidden} with a bucket left out, {several} in three runs"
        );
        assert!(edge_drawn, "the bucket at the section's edge");
+        if let Some(t) = &timing {
+            let parts = t.part_medians();
+            let names = |pass: &str| {
+                let parts = parts.iter().find(|p| p.0 == pass)?;
+                Some(parts.1.iter().map(|p| p.0.as_str()).collect::<Vec<_>>())
+            };
+            assert_eq!(
+                names("GPU culling"),
+                Some(vec!["apply", "cull", "scan", "scatter"]),
+                "{parts:?}"
+            );
+        }
        assert!(culled > 2_000, "{culled} within the distance left out");
        assert!(faded * 10 > compared, "{faded} fading of {compared} drawn");
        assert!(
@@ -3136,6 +3198,113 @@ mod tests {
        );
    }

+    /// Detail times both phases and the uploads and leaves counts and draws as an untimed frame's.
+    #[test]
+    fn detail_times_both_phases_and_leaves_the_draws_alone() {
+        on_each_device(|device, queue| {
+            let mut rng = Rng(0x1F83_D9AB_FB41_BD6B);
+            let (frustum, _) = view(&mut rng);
+            let records: Vec<Record> = (0..400)
+                .map(|i| {
+                    let key = (rng.range(-6, 6), rng.range(0, 23), rng.range(-6, 6));
+                    Record::new(
+                        key,
+                        i % 3,
+                        u64::from(i) * 1024,
+                        1 + rng.below(500),
+                        UNBOUNDED,
+                    )
+                })
+                .collect();
+            let mut timing = PassTiming::new(device, queue);
+            let early = device
+                .features()
+                .contains(wgpu::Features::SHADER_EARLY_DEPTH_TEST);
+            let Some(t) = timing.as_mut().filter(|_| early) else {
+                eprintln!("no timestamps or early depth test: skipped");
+                return;
+            };
+            t.set_detail(true);
+            let run = |timing: &mut Option<PassTiming>| {
+                let mut gpu = GpuCulling::new(device, Some(wgpu::TextureFormat::Rgba8Unorm))
+                    .expect("the pass");
+                let mut uploads = Uploads::new(device);
+                for r in &records {
+                    gpu.records.insert(*r);
+                }
+                let mut out = Vec::new();
+                for frame in 0..12 {
+                    if let Some(t) = timing {
+                        t.begin(device, queue);
+                    }
+                    let mut encoder = device.create_command_encoder(&Default::default());
+                    let input = FrameInputs {
+                        camera: DVec3::new(0.5, 70.0, 0.5),
+                        min_y: -64,
+                        sections: 24,
+                        radius: 5,
+                        frustum: &frustum,
+                        reach: None,
+                        eye: None,
+                        view_proj: Mat4::IDENTITY,
+                        occlude: true,
+                    };
+                    let prepared = gpu.prepare(
+                        device,
+                        queue,
+                        &mut uploads,
+                        &mut encoder,
+                        &input,
+                        timing.as_mut(),
+                    );
+                    assert_eq!(prepared, Prepared::Gpu, "frame {frame}");
+                    assert!(gpu.occluding(), "frame {frame}: phase 2 runs");
+                    gpu.dispatch(&mut encoder, timing.as_mut());
+                    gpu.compact(&mut encoder, timing.as_mut());
+                    uploads.finish(&encoder);
+                    queue.submit([encoder.finish()]);
+                    if let Some(t) = timing {
+                        t.submitted(queue);
+                    }
+                    device.poll(wgpu::PollType::wait_indefinitely()).unwrap();
+                    let pages = u64::from(gpu.pass_pages);
+                    out.push((
+                        read(device, queue, &gpu.counts.buffer, (STATS + 2 * pages) * 4),
+                        read(device, queue, &gpu.draws.buffer, gpu.draws.bytes),
+                    ));
+                }
+                out
+            };
+            let timed = run(&mut timing);
+            let plain = run(&mut None);
+            assert_eq!(timed, plain, "detail changes what is drawn");
+            let t = timing.as_ref().expect("the timer");
+            let parts = t.part_medians();
+            let names = |pass: &str| {
+                let parts = parts.iter().find(|p| p.0 == pass)?;
+                Some(parts.1.iter().map(|p| p.0.as_str()).collect::<Vec<_>>())
+            };
+            assert_eq!(
+                names("GPU culling"),
+                Some(vec!["apply", "cull", "scan", "scatter"]),
+                "{parts:?}"
+            );
+            assert_eq!(
+                names("GPU culling phase 2"),
+                Some(vec!["count2", "scan2", "scatter2"]),
+                "{parts:?}"
+            );
+            // The uploads are a pass of their own, never a part of one.
+            assert_eq!(names("GPU culling uploads"), None, "{parts:?}");
+            let passes = t.medians();
+            assert_eq!(
+                passes.iter().any(|p| p.0 == "GPU culling uploads"),
+                t.detail_support().encoder_stamps,
+                "{passes:?}"
+            );
+        });
+    }
+
    /// The statistics come back with their frame, in place and from the submit
    /// thread, submitted as gfx.rs submits frames (`submit_later`, or in place
    /// with its `after` handed back): three frames on their way fill the ring, a
@@ -3377,7 +3546,7 @@ struct Quad {
                view_proj: Mat4::IDENTITY,
                occlude: false,
            };
-            let prepared = gpu.prepare(device, queue, &mut uploads, &mut encoder, &input);
+            let prepared = gpu.prepare(device, queue, &mut uploads, &mut encoder, &input, None);
            assert_eq!(prepared, Prepared::Gpu, "frame {frame}");
            let mut params = tables(&input, &mut words).expect("the planes fit");
            params.pages = gpu.pass_pages;
@@ -5,6 +5,10 @@
 //! or scRGB swapchain at the player's paper white, expanding the world's
 //! highlights towards their peak brightness. The world is copied aside before
 //! the hand and HUD so only it is expanded.
+//!
+//! On the float frame Horizon's world light is the same on every display (`TIERS`,
+//! `SUNLIT_GAIN`, up to `SCENE_PEAK`), and the tone curve alone fits it to the display's
+//! peak (docs/design/hdr-linear-light.md, step 6a).

 /// The swapchain HDR output presents to.
 #[derive(Clone, Copy, PartialEq, Eq, Debug)]
@@ -99,38 +103,53 @@ struct Layered {
    params: wgpu::Buffer,
 }

-/// How one tier of light sources (`mesher::hdr_tier`) shines: `share` of the headroom for
-/// its brightest pixels, lifted from brightness `start` (none) to `full` (all of it), the
-/// texel's own brightness before lighting.
+/// How one tier of light sources (`mesher::hdr_tier`) shines: its brightest pixels are
+/// multiplied by `gain`, in multiples of paper white, lifted from brightness `start` (none) to
+/// `full` (all of it), the texel's own brightness before lighting.
 #[derive(Clone, Copy, Debug, PartialEq)]
 pub struct Tier {
-    pub share: f32,
+    pub gain: f32,
    pub start: f32,
    pub full: f32,
 }
-/// Low, incandescent, bright and very bright.
+/// Low, incandescent, bright and very bright: faint glowers such as magma, flames and lava,
+/// glowstone and campfires, the sun.
 pub const TIERS: [Tier; 4] = [
    Tier {
-        share: 0.2,
+        gain: 1.6,
        start: 0.08,
        full: 0.09,
    },
    Tier {
-        share: 0.5,
+        gain: 2.4,
        start: 0.14,
        full: 0.38,
    },
    Tier {
-        share: 0.6,
+        gain: 2.8,
        start: 0.14,
        full: 0.38,
    },
    Tier {
-        share: 1.0,
+        gain: 4.0,
        start: 0.14,
        full: 0.38,
    },
 ];
+/// The scene's peak, in multiples of paper white: just above the brightest light the world
+/// writes (the sun's disc, white at the very bright tier's 4), and what the tone curve maps
+/// onto the display's peak; light past it (where the sky adds onto the sun) is held at it. The
+/// world is mastered for a 1000-nit display at ITU-R BT.2408's 203-nit reference white, as
+/// HDR10 content usually is: there it shows as written, a dimmer display eases its highlights
+/// into its peak (BT.2390's EETF), and a brighter one shows it as at 1000.
+pub const SCENE_PEAK: f32 = 1000.0 / 203.0;
+/// HDR lighting: what the strongest light multiplies a surface by (`hdr_light.wgsl`).
+pub const SUNLIT_GAIN: f32 = 3.0;
+/// The compatibility frame's tiers (the 16-bit or 8-bit frame, until step 5 removes it): each
+/// one's share of the display's headroom, as before one peak, so the look HDR has by default
+/// changes once, when the float frame replaces it.
+const COMPAT_SHARES: [f32; 4] = [0.2, 0.5, 0.6, 1.0];
+
 /// Which pixels of a light source's sprite may shine (`hdr_stats.wgsl`), as a fraction of
 /// the way from its darkest to its brightest opaque pixel: `parts` for one whose bright parts
 /// shine (a torch's flame, not its handle), `whole` for one that shines all over
@@ -331,7 +350,7 @@ impl Hdr {
        let params = || {
            device.create_buffer(&wgpu::BufferDescriptor {
                label: Some("Horizon HDR parameters"),
-                size: 64,
+                size: 80,
                usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
                mapped_at_creation: false,
            })
@@ -944,16 +963,19 @@ impl Hdr {
        })
    }

+    /// What the world's writers read (`hdr_written`): the scene's peak, HDR lighting's gain,
+    /// world/look and debug, then the tiers' gains. No part of the display reaches them.
    pub(super) fn draw_params(&self, world: bool) -> ([f32; 4], [f32; 4]) {
        let p = self.params(world, false);
-        ([p[1], p[7], p[2], p[3]], p[8..12].try_into().unwrap())
+        let sunlit = if self.lighting { SUNLIT_GAIN } else { 1.0 };
+        ([SCENE_PEAK, sunlit, p[2], p[3]], self.tiers.map(|t| t.gain))
    }

    /// hdr.wgsl's `Params`.
-    fn params(&self, world: bool, pq: bool) -> [f32; 16] {
+    fn params(&self, world: bool, pq: bool) -> [f32; 20] {
        let paper = self.paper_white.max(1.0);
        let c = self.calibration;
-        let mut params = [0.0; 16];
+        let mut params = [0.0; 20];
        params[..5].copy_from_slice(&[
            paper / 80.0,
            (self.peak / paper).max(1.0),
@@ -968,12 +990,17 @@ impl Hdr {
        } else {
            1.0
        };
-        for (i, t) in self.tiers.iter().enumerate() {
-            params[8 + i] = t.share;
-        }
+        params[8..12].copy_from_slice(&COMPAT_SHARES);
        params[12] = c.map_or(0.0, |c| c.step as f32);
        params[13] = c.map_or(0.0, |c| c.nits);
        params[14] = c.map_or(0.0, |c| c.band);
+        // Only Horizon's lifted world is known to end at the scene's peak; elsewhere (HDR
+        // Lighting off, a pack's own light, the title) the curve's source follows the display.
+        params[16] = if world && self.lighting {
+            SCENE_PEAK
+        } else {
+            0.0
+        };
        params
    }

@@ -1050,8 +1077,9 @@ fn logo_mask(device: &wgpu::Device, queue: &wgpu::Queue) -> wgpu::TextureView {
        .create_view(&Default::default())
 }

-/// What the strongest light multiplies a surface by, in HDR lighting: 4, which looked right
-/// across biomes; less only where there is little headroom to ease into (`hdr.wgsl`).
+/// The compatibility frame's HDR lighting (`fs_hdr`): what the strongest light multiplies a
+/// surface by, 4, which looked right across biomes; less only where there is little headroom
+/// to ease into. The float frame's is `SUNLIT_GAIN`.
 fn scene_gain(peak: f32, paper_white: f32) -> f32 {
    (peak / paper_white.max(1.0) * 1.75).clamp(1.0, 4.0)
 }
@@ -1069,7 +1097,8 @@ mod tests {
            return;
        };
        // All 8-bit marks, both easing policies, non-grey and over-white colours, look,
-        // debug, headroom and tier shares; half-float neighbours straddle mark boundaries.
+        // debug, headroom and tier shares; half-float neighbours straddle mark boundaries. The
+        // writers take the gain that a share gives.
        let source = include_str!("../hdr_light.wgsl").to_owned()
            + r#"
 struct ReferenceParams { peak: f32, scene: f32, world: f32, debug: f32, share: vec4<f32> }
@@ -1088,19 +1117,20 @@ var<private> params: ReferenceParams;
        select(0.0, 1.0, (mode & 32u) != 0u), vec4(0.2, 0.5, 0.6, 1.0));
    let color = select(vec3(0.9, 0.4, 0.02), vec3(1.4, 0.8, 0.2), (mode & 64u) != 0u);
    let expected = reference_lit(color, mark, shows, eased);
+    let gains = 1.0 + (params.peak - 1.0) * params.share;
    let actual = hdr_mark_light(color, mark, shows, eased,
-        vec4(params.peak, params.scene, params.world, params.debug), params.share);
+        vec4(params.peak, params.scene, params.world, params.debug), (params.peak - 1.0) * params.share);
    errors[i] = select(0u, 1u, any(abs(expected.light - actual.light) > vec3(1e-6)) || expected.lifted != actual.lifted);
    // Gain stays above the tone knee until the separate tone curve runs.
    let gain = 1.0 + 3.0 * (1.0 - 194.0 / 255.0) / 0.24;
-    let white = hdr_written(vec3(1.0), 0.76, vec4(5.0, 4.0, 1.0, 0.0), params.share);
+    let white = hdr_written(vec3(1.0), 0.76, vec4(5.0, 4.0, 1.0, 0.0), gains);
    errors[i] |= select(0u, 4u, any(abs(pow(white, vec3(2.2)) - vec3(gain)) > vec3(1e-5)));
    let boundary = (f32(i % 255u) + 0.5) / 255.0;
    for (var step = -1; step <= 1; step++) {
        let stored = unpack2x16float(pack2x16float(vec2(boundary + f32(step) / 65536.0))).x;
        let quantized = round(saturate(stored) * 255.0) / 255.0;
-        let want = pow(reference_lit(color, quantized, params.world > 0.5 && params.peak > 1.0, false).light, vec3(1.0 / 2.2));
-        let got = hdr_written(color, stored, vec4(params.peak, params.scene, params.world, params.debug), params.share);
+        let want = pow(reference_lit(color, quantized, params.world > 0.5, false).light, vec3(1.0 / 2.2));
+        let got = hdr_written(color, stored, vec4(params.peak, params.scene, params.world, params.debug), gains);
        errors[i] |= select(0u, 2u, any(abs(want - got) > vec3(1e-6)));
    }
 }
@@ -1319,10 +1349,12 @@ var<private> params: ReferenceParams;

    // Independent pre-refactor light arithmetic applied to a compatibility attachment.
    // Float targets in these tests only receive the resulting colour and coverage.
+    // `lift`: the reference's peak, HDR lighting gain, world and debug, then the tiers' shares
+    // of the headroom up to that peak (`writers_lift`, `display_lift`).
    pub(super) fn legacy_light(
        device: &wgpu::Device,
        encoder: &mut wgpu::CommandEncoder,
-        hdr: &Hdr,
+        lift: [[f32; 4]; 2],
        source: &wgpu::Texture,
        target: &wgpu::Texture,
    ) {
@@ -1345,7 +1377,7 @@ struct ReferenceParams { peak: f32, scene: f32, world: f32, debug: f32, share: v
@fragment fn fs() -> @location(0) vec4<f32> {
    let c = textureLoad(source, vec2(0), 0);
    let mark = round(saturate(c.a) * 255.0) / 255.0;
-    let light = reference_lit(c.rgb, mark, params.world > 0.5 && params.peak > 1.0, false).light;
+    let light = reference_lit(c.rgb, mark, params.world > 0.5, false).light;
    return vec4(pow(light, vec3(1.0 / 2.2)), 1.0);
 }
 "#)
@@ -1373,10 +1405,9 @@ struct ReferenceParams { peak: f32, scene: f32, world: f32, debug: f32, share: v
            multiview_mask: None,
            cache: None,
        });
-        let (settings, shares) = hdr.draw_params(true);
        let params = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
            label: None,
-            contents: bytemuck::cast_slice(&[settings, shares]),
+            contents: bytemuck::cast_slice(&lift),
            usage: wgpu::BufferUsages::UNIFORM,
        });
        let view = source.create_view(&Default::default());
@@ -1404,6 +1435,19 @@ struct ReferenceParams { peak: f32, scene: f32, world: f32, debug: f32, share: v
        );
    }

+    /// The float frame's writers' light as `legacy_light` takes it: each tier's gain as a share
+    /// of the headroom up to the scene's peak.
+    pub(super) fn writers_lift(hdr: &Hdr) -> [[f32; 4]; 2] {
+        let (settings, gains) = hdr.draw_params(true);
+        [settings, gains.map(|g| (g - 1.0) / (settings[0] - 1.0))]
+    }
+
+    /// The compatibility frame's display pass's light (`fs_hdr`) as `legacy_light` takes it.
+    fn display_lift(hdr: &Hdr) -> [[f32; 4]; 2] {
+        let p = hdr.params(true, false);
+        [[p[1], p[7], p[2], p[3]], p[8..12].try_into().unwrap()]
+    }
+
    #[test]
    fn direct_light_matches_the_legacy_non_float_display_below_the_tone_knee() {
        let Some((device, queue)) = gpu() else {
@@ -1416,8 +1460,9 @@ struct ReferenceParams { peak: f32, scene: f32, world: f32, debug: f32, share: v
            eprintln!("legacy display GPU skipped: 16-bit UNORM unavailable");
            return;
        }
-        // Compare the compatibility display lift with direct colour under the layered HUD.
-        // The frozen oracle supplies the writer's light from a non-float attachment.
+        // Compare the compatibility display lift with direct colour under the layered HUD:
+        // the frozen oracle turns the marks into the light that display gives them, and the
+        // layered display, whose curve is the identity at 1000 nits, must show it the same.
        let shown = |layered: bool, world: [f64; 4]| {
            let mut hdr = Hdr::with_debug(
                &device,
@@ -1441,7 +1486,14 @@ struct ReferenceParams { peak: f32, scene: f32, world: f32, debug: f32, share: v
                if world[3] == 1.0 {
                    fill(&mut encoder, &frame, world);
                } else {
-                    legacy_light(&device, &mut encoder, &hdr, &marked, &frame);
+                    // The light the compatibility frame shows: its own lift, not the writers'.
+                    legacy_light(
+                        &device,
+                        &mut encoder,
+                        display_lift(&legacy),
+                        &marked,
+                        &frame,
+                    );
                }
                hdr.begin(&queue, true);
                hdr.tonemap(&mut encoder, None);
@@ -1480,78 +1532,206 @@ struct ReferenceParams { peak: f32, scene: f32, world: f32, debug: f32, share: v
        assert!(above[0] > white[0] && above[1] > white[1]);
    }

+    /// The world's writers read nothing of the display: the same gains and the same scene peak
+    /// at any paper white and peak (docs/design/hdr-linear-light.md, step 6a).
    #[test]
-    fn the_tone_curve_eases_light_into_the_peak() {
+    fn the_writers_light_is_the_same_on_every_display() {
        let Some((device, queue)) = gpu() else {
            return;
        };
        let mut hdr = Hdr::with_debug(&device, &queue, F::Rgba16Float, Output::Pq, true, None);
-        (hdr.paper_white, hdr.peak) = (203.0, 1000.0);
-        let headroom = 1000.0 / 203.0;
-        // The frame holding `color` (in gamma, as it stores light) after `passes` ran on it.
-        let after =
-            |hdr: &mut Hdr, color: [f64; 4], passes: &dyn Fn(&Hdr, &mut wgpu::CommandEncoder)| {
-                let frame = hdr.frame(&device, [1, 1]);
-                let mut encoder = device.create_command_encoder(&Default::default());
-                fill(&mut encoder, &frame, color);
-                hdr.begin(&queue, true);
-                passes(hdr, &mut encoder);
-                texel(&device, &queue, encoder, &frame)
-            };
-        let tonemap = |hdr: &Hdr, encoder: &mut wgpu::CommandEncoder| hdr.tonemap(encoder, None);
+        let written = hdr.draw_params(true);
+        assert_eq!(
+            written,
+            (
+                [super::SCENE_PEAK, super::SUNLIT_GAIN, 1.0, 0.0],
+                [1.6, 2.4, 2.8, 4.0]
+            )
+        );
+        for (paper, peak) in [
+            (203.0, 300.0),
+            (203.0, 600.0),
+            (203.0, 1500.0),
+            (400.0, 600.0),
+            (480.0, 200.0),
+            (80.0, 10000.0),
+        ] {
+            (hdr.paper_white, hdr.peak) = (paper, peak);
+            assert_eq!(hdr.draw_params(true), written, "{paper}/{peak}");
+            assert_eq!(
+                hdr.params(true, false)[16],
+                super::SCENE_PEAK,
+                "{paper}/{peak}"
+            );
+        }
+        // The title, and frames Horizon doesn't light (HDR Lighting off, a pack drawing):
+        // nothing says where their light ends, so the curve's source follows the display.
+        assert_eq!(hdr.params(false, false)[16], 0.0);
+        hdr.lighting = false;
+        assert_eq!(hdr.draw_params(true).0[1], 1.0);
+        assert_eq!(hdr.params(true, false)[16], 0.0);
+    }
+
+    /// The tone curve maps the scene's peak S onto the display's peak T with ITU-R BT.2390's
+    /// EETF, keeping hue, after holding light above S at S. Checkpoints are worked out apart
+    /// from the shader, in f64 from SMPTE ST 2084 and BT.2390.
+    #[test]
+    fn the_tone_curve_maps_the_scene_peak_onto_the_display() {
+        let Some((device, queue)) = gpu() else {
+            return;
+        };
+        let mut hdr = Hdr::with_debug(&device, &queue, F::Rgba16Float, Output::Pq, true, None);
+        let scene_peak = super::SCENE_PEAK;
+        // The frame holding `color` (in gamma, as it stores light), after the curve if `curve`.
+        let through = |hdr: &mut Hdr, color: [f64; 4], curve: bool| {
+            let frame = hdr.frame(&device, [1, 1]);
+            let mut encoder = device.create_command_encoder(&Default::default());
+            fill(&mut encoder, &frame, color);
+            hdr.begin(&queue, true);
+            if curve {
+                hdr.tonemap(&mut encoder, None);
+            }
+            texel(&device, &queue, encoder, &frame)
+        };
+        // `exact`, or within one half-float step: S's own gamma rounds up in half float, to
+        // light just above S that the curve holds at S, and whether that comes back to the same
+        // half float depends on the GPU's rounding (one step lower on an Apple M4 Pro).
+        let unchanged = |hdr: &mut Hdr, color: [f64; 4], exact: bool| {
+            let (got, stored) = (through(hdr, color, true), through(hdr, color, false));
+            (0..4).all(|c| {
+                got[c] == stored[c] || !exact && (got[c] - stored[c]).abs() <= stored[c] / 1024.0
+            })
+        };
        // Linear light in and out, in units of paper white.
-        let eased = |hdr: &mut Hdr, light: [f32; 3]| {
+        let mapped = |hdr: &mut Hdr, light: [f32; 3]| {
            let [r, g, b] = light.map(|c| f64::from(c.powf(1.0 / 2.2)));
-            let [r, g, b, a] = after(hdr, [r, g, b, 1.0], &tonemap);
+            let [r, g, b, a] = through(hdr, [r, g, b, 1.0], true);
            assert_eq!(a, 1.0);
            [r, g, b].map(|c| c.powf(2.2))
        };
        let near = |got: f32, want: f32| (got - want).abs() <= 0.005 * want.max(1.0);
-        // Up to the knee (60% of the peak) the light stays exactly as stored.
-        for light in [0.0f32, 0.5, 1.0, 2.0, 2.9] {
-            let g = f64::from(light.powf(1.0 / 2.2));
-            let stored = after(&mut hdr, [g, g * 0.5, 0.0, 1.0], &|_, _| {});
-            assert_eq!(
-                after(&mut hdr, [g, g * 0.5, 0.0, 1.0], &tonemap),
-                stored,
-                "{light}"
-            );
-        }
-        // Past it, BT.2390's EETF in PQ at 203 and 1000 nits, with the source's peak at 2771
-        // nits (13.7 times paper white), worked out apart from the shader.
-        for (light, want) in [
-            (3.5, 3.43791),
-            (4.0, 3.78351),
-            (headroom, 4.23556),
-            (8.0, 4.82043),
-            (12.0, 4.92462),
-            (50.0, headroom),
+        // A display at or above the mastering one (T >= S): every stored value up to S comes
+        // out exactly as it went in, grey or coloured, and light above S is held at S with its
+        // hue, so 1500 and 10 000 nits show what 1000 does; so do the settings' extremes (Paper
+        // White 10 to 480 nits, Peak up to 10 000) wherever T reaches S.
+        for (paper, peak) in [
+            (203.0, 1000.0),
+            (203.0, 1500.0),
+            (203.0, 10000.0),
+            (480.0, 10000.0),
+            (10.0, 200.0),
        ] {
-            let [r, ..] = eased(&mut hdr, [light; 3]);
-            assert!(near(r, want), "{light}: {r}, not {want}");
+            (hdr.paper_white, hdr.peak) = (paper, peak);
+            for i in 0..=64 {
+                let g = f64::from((scene_peak * i as f32 / 64.0).powf(1.0 / 2.2));
+                let exact = i < 64;
+                assert!(unchanged(&mut hdr, [g, g, g, 1.0], exact), "{peak}: {i}");
+                assert!(
+                    unchanged(&mut hdr, [g, g * 0.6, g * 0.1, 1.0], exact),
+                    "{peak}: {i}"
+                );
+            }
+            for light in [8.0f32, 50.0] {
+                let [r, g, b] = mapped(&mut hdr, [light, light / 4.0, 0.0]);
+                assert!(
+                    near(r, scene_peak) && near(g * 4.0, r) && b == 0.0,
+                    "{peak}: {light}: {r} {g} {b}"
+                );
+            }
        }
-        // It rises, stays under the peak, and the brightest channel scales the others: the
-        // light keeps its hue.
-        let mut last = 0.0;
-        for i in 0..40 {
-            let light = 2.5 * 1.08f32.powi(i);
-            let [r, g, b] = eased(&mut hdr, [light, light / 4.0, 0.0]);
-            assert!(r >= last - 0.001 && r <= headroom * 1.002, "{light}: {r}");
-            assert!(near(g * 4.0, r) && b == 0.0, "{light}: {r} {g} {b}");
-            last = r;
+        // Dimmer displays: unchanged up to the knee, then the EETF into T, T at S and past it.
+        // At 300 nits the knee falls just below white (161 nits): white shows at 198 nits
+        // where the gates' curve, whose source followed the display, kept it at 203; the
+        // highlights above it keep more of their steps.
+        for (paper, peak, knee, checkpoints) in [
+            (
+                203.0,
+                600.0,
+                2.0,
+                &[
+                    (2.5, 2.47516),
+                    (3.0, 2.75699),
+                    (4.0, 2.9404),
+                    (scene_peak, 600.0 / 203.0),
+                    (8.0, 600.0 / 203.0),
+                ][..],
+            ),
+            (
+                203.0,
+                300.0,
+                0.75,
+                &[
+                    (0.9, 0.89289),
+                    (1.0, 0.97365),
+                    (1.2, 1.10406),
+                    (1.4, 1.20134),
+                    (2.0, 1.36833),
+                    (4.0, 1.47641),
+                    (8.0, 300.0 / 203.0),
+                ],
+            ),
+            (
+                400.0,
+                600.0,
+                0.8,
+                &[
+                    (1.0, 0.97973),
+                    (1.2, 1.11501),
+                    (1.5, 1.25607),
+                    (2.0, 1.38818),
+                    (scene_peak, 1.5),
+                ],
+            ),
+            // No headroom (a peak under paper white): the scene is compressed into white.
+            (
+                203.0,
+                150.0,
+                0.4,
+                &[
+                    (1.0, 0.78346),
+                    (1.5, 0.90244),
+                    (2.0, 0.95589),
+                    (4.0, 0.99944),
+                    (scene_peak, 1.0),
+                ],
+            ),
+        ] {
+            (hdr.paper_white, hdr.peak) = (paper, peak);
+            for light in [0.0f32, 0.3, knee] {
+                let g = f64::from(light.powf(1.0 / 2.2));
+                assert!(
+                    unchanged(&mut hdr, [g, g * 0.5, 0.0, 1.0], true),
+                    "{paper}/{peak}: {light}"
+                );
+            }
+            for &(light, want) in checkpoints {
+                let [r, ..] = mapped(&mut hdr, [light; 3]);
+                assert!(near(r, want), "{paper}/{peak}: {light}: {r}, not {want}");
+            }
+            // It rises, stays under the peak, and the brightest channel scales the others; a
+            // half float's step in gamma is 0.1% of the light near white.
+            let headroom = (peak / paper).max(1.0);
+            let mut last = 0.0;
+            for i in 0..40 {
+                let light = 0.5 * 1.08f32.powi(i);
+                let [r, g, b] = mapped(&mut hdr, [light, light / 4.0, 0.0]);
+                assert!(
+                    r >= last * 0.998 && r <= headroom * 1.002,
+                    "{peak}: {light}: {r}"
+                );
+                assert!(near(g * 4.0, r) && b == 0.0, "{peak}: {light}: {r} {g} {b}");
+                last = r;
+            }
        }
-        // A display with little headroom, 300 nits at a paper white of 203: the knee sits at
-        // white, so all that SDR shows stays as it is, and the source's peak is 645 nits.
-        hdr.peak = 300.0;
+        // Light Horizon doesn't lift (HDR Lighting off, a 0.2 pack's own) has no known peak:
+        // the curve's source follows the display, the knee at 60% of its peak and at least
+        // white, as before one peak. At 300 nits the source's peak is 645 nits.
+        hdr.lighting = false;
+        (hdr.paper_white, hdr.peak) = (203.0, 300.0);
        let headroom = 300.0 / 203.0;
-        for light in [0.5f32, 0.9, 1.0] {
+        for light in [0.0f32, 0.5, 0.9, 1.0] {
            let g = f64::from(light.powf(1.0 / 2.2));
-            let stored = after(&mut hdr, [g, g * 0.5, 0.0, 1.0], &|_, _| {});
-            assert_eq!(
-                after(&mut hdr, [g, g * 0.5, 0.0, 1.0], &tonemap),
-                stored,
-                "{light}"
-            );
+            assert!(unchanged(&mut hdr, [g, g * 0.5, 0.0, 1.0], true), "{light}");
        }
        for (light, want) in [
            (1.2, 1.16839),
@@ -1560,12 +1740,12 @@ struct ReferenceParams { peak: f32, scene: f32, world: f32, debug: f32, share: v
            (2.0, 1.44024),
            (4.0, headroom),
        ] {
-            let [r, ..] = eased(&mut hdr, [light; 3]);
+            let [r, ..] = mapped(&mut hdr, [light; 3]);
            assert!(near(r, want), "{light}: {r}, not {want}");
        }
-        // No headroom (a peak below paper white): a clip at white, channel by channel.
+        // With no headroom there, a clip at white, channel by channel.
        hdr.peak = 150.0;
-        let [r, g, b] = eased(&mut hdr, [1.5, 0.5, 0.2]);
+        let [r, g, b] = mapped(&mut hdr, [1.5, 0.5, 0.2]);
        assert!(r == 1.0 && near(g, 0.5) && near(b, 0.2), "{r} {g} {b}");
    }

@@ -1582,7 +1762,7 @@ struct ReferenceParams { peak: f32, scene: f32, world: f32, debug: f32, share: v
        (hdr.paper_white, hdr.peak, hdr.black) = (250.0, 800.0, 0.0);
        (hdr.ui, hdr.look, hdr.lighting) = (0.5, false, false);
        hdr.masks.parts = 0.4;
-        hdr.tiers[1].share = 0.7;
+        hdr.tiers[1].gain = 3.0;
        hdr.debug = true;
        hdr.calibration = Some(super::Calibration {
            step: 2,
@@ -1,6 +1,6 @@
 use super::{
    Hdr, Output,
-    tests::{gpu, legacy_light, texel},
+    tests::{gpu, legacy_light, texel, writers_lift},
 };
 use wgpu::TextureFormat as F;
 use wgpu::util::DeviceExt;
@@ -648,7 +648,7 @@ impl<'a> Draw<'a> {
        }
        if !written && !self.raw {
            let light = hdr.frame(self.device, [1, 1]);
-            legacy_light(self.device, &mut encoder, hdr, &frame, &light);
+            legacy_light(self.device, &mut encoder, writers_lift(hdr), &frame, &light);
            return texel(self.device, self.queue, encoder, &light);
        }
        texel(self.device, self.queue, encoder, &frame)
@@ -662,7 +662,7 @@ fn float_plain_fragments_keep_rgb_and_write_only_coverage() {
        return;
    };
    let mut hdr = Hdr::with_debug(&device, &queue, F::Rgba16Float, Output::Pq, true, None);
-    let (settings, shares) = hdr.draw_params(true);
+    let (settings, gains) = hdr.draw_params(true);
    let mut cases = 0;
    for hdr_on in [false, true] {
        let globals = super::super::Globals {
@@ -677,7 +677,7 @@ fn float_plain_fragments_keep_rgb_and_write_only_coverage() {
            hdr_windows: hdr.windows(),
            hdr_light: [0.8, 0.8, f32::from(u8::from(hdr_on)), 0.0],
            hdr_settings: settings,
-            hdr_shares: shares,
+            hdr_gains: gains,
            ..bytemuck::Zeroable::zeroed()
        };
        for terrain in [true, false] {
@@ -739,7 +739,7 @@ fn float_stars_keep_the_original_rgb_with_brightness_as_coverage() {
        return;
    };
    let mut hdr = Hdr::with_debug(&device, &queue, F::Rgba16Float, Output::Pq, true, None);
-    let (settings, shares) = hdr.draw_params(true);
+    let (settings, gains) = hdr.draw_params(true);
    // Frozen f030d9c80 fragment: the original written branch and its marked fallback.
    let source = include_str!("../hdr_light.wgsl").to_owned()
        + include_str!("stars.wgsl")
@@ -750,7 +750,7 @@ fn float_stars_keep_the_original_rgb_with_brightness_as_coverage() {
@fragment fn reference() -> @location(0) vec4<f32> {
    let b = stars.color.a;
    if HDR_WRITE_LIGHT && stars.hdr_light.w != 0.0 {
-        return vec4(hdr_written(stars.color.rgb * b, 0.175, stars.hdr_settings, stars.hdr_shares), b);
+        return vec4(hdr_written(stars.color.rgb * b, 0.175, stars.hdr_settings, stars.hdr_gains), b);
    }
    return vec4(stars.color.rgb * b, 0.175);
 }
@@ -763,7 +763,7 @@ fn float_stars_keep_the_original_rgb_with_brightness_as_coverage() {
        let mut data = [0.0_f32; 32];
        data[16..20].copy_from_slice(&[0.7, 0.8, 0.9, 0.35]);
        data[20..24].copy_from_slice(&settings);
-        data[24..28].copy_from_slice(&shares);
+        data[24..28].copy_from_slice(&gains);
        data[31] = gain;
        let uniform = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
            label: None,
@@ -908,7 +908,7 @@ fn actual_opaque_writers_match_the_legacy_non_float_oracle() {
    }
    let mut hdr = Hdr::with_debug(&device, &queue, F::Rgba16Float, Output::Pq, true, None);
    (hdr.paper_white, hdr.peak) = (203.0, 1000.0);
-    let (settings, shares) = hdr.draw_params(true);
+    let (settings, gains) = hdr.draw_params(true);
    let mut count = 0;
    for fog in [0.0, 0.5, 1.0] {
        for visibility in [1.0, 0.4] {
@@ -921,7 +921,7 @@ fn actual_opaque_writers_match_the_legacy_non_float_oracle() {
                hdr_windows: hdr.windows(),
                hdr_light: [0.8, 0.8, 1.0, 1.0],
                hdr_settings: settings,
-                hdr_shares: shares,
+                hdr_gains: gains,
                ..bytemuck::Zeroable::zeroed()
            };
            for terrain in [true, false] {
@@ -968,7 +968,7 @@ fn actual_translucent_writers_blend_their_own_light() {
        return;
    };
    let mut hdr = Hdr::with_debug(&device, &queue, F::Rgba16Float, Output::Pq, true, None);
-    let (settings, shares) = hdr.draw_params(true);
+    let (settings, gains) = hdr.draw_params(true);
    let globals = super::super::Globals {
        fog: [0.0, 100.0, 0.0, 100.0],
        fog_ends: [100.0, 100.0, 0.0, 0.0],
@@ -977,7 +977,7 @@ fn actual_translucent_writers_blend_their_own_light() {
        hdr_windows: hdr.windows(),
        hdr_light: [0.8, 0.8, 1.0, 1.0],
        hdr_settings: settings,
-        hdr_shares: shares,
+        hdr_gains: gains,
        ..bytemuck::Zeroable::zeroed()
    };
    // Texel alpha 100 is clear glass's kind of texel, below the 0.6 the marked frame's
@@ -1035,14 +1035,14 @@ fn unmarked_entity_users_keep_their_source_gain() {
        return;
    }
    let mut hdr = Hdr::with_debug(&device, &queue, F::Rgba16Float, Output::Pq, true, None);
-    let (settings, shares) = hdr.draw_params(true);
+    let (settings, gains) = hdr.draw_params(true);
    let globals = super::super::Globals {
        fog: [0.0, 100.0, 0.0, 100.0],
        fog_ends: [100.0, 100.0, 0.0, 0.0],
        hdr_windows: hdr.windows(),
        hdr_light: [1.0, 1.0, 1.0, 1.0],
        hdr_settings: settings,
-        hdr_shares: shares,
+        hdr_gains: gains,
        ..bytemuck::Zeroable::zeroed()
    };
    let draw = Draw::new(&device, &queue, false, &globals, 255);
@@ -1079,13 +1079,13 @@ fn additive_texels_below_the_mark_cutoff_keep_their_gain() {
        return;
    }
    let mut hdr = Hdr::with_debug(&device, &queue, F::Rgba16Float, Output::Pq, true, None);
-    let (settings, shares) = hdr.draw_params(true);
+    let (settings, gains) = hdr.draw_params(true);
    let globals = super::super::Globals {
        fog: [0.0, 100.0, 0.0, 100.0],
        hdr_windows: hdr.windows(),
        hdr_light: [1.0, 1.0, 1.0, 1.0],
        hdr_settings: settings,
-        hdr_shares: shares,
+        hdr_gains: gains,
        ..bytemuck::Zeroable::zeroed()
    };
    let draw = Draw::new(&device, &queue, false, &globals, 16);
@@ -1129,7 +1129,7 @@ fn check_oit_writer(terrain: bool, kind: &str, overlay: u32, tier: u32, alphas:
    }))
    .unwrap();
    let mut hdr = Hdr::with_debug(&device, &queue, F::Rgba16Float, Output::Pq, true, None);
-    let (settings, shares) = hdr.draw_params(true);
+    let (settings, gains) = hdr.draw_params(true);
    let globals = super::super::Globals {
        fog: [0.0, 100.0, 0.0, 100.0],
        fog_ends: [100.0, 100.0, 0.0, 0.0],
@@ -1138,7 +1138,7 @@ fn check_oit_writer(terrain: bool, kind: &str, overlay: u32, tier: u32, alphas:
        hdr_windows: hdr.windows(),
        hdr_light: [0.8, 0.8, 1.0, 1.0],
        hdr_settings: settings,
-        hdr_shares: shares,
+        hdr_gains: gains,
        ..bytemuck::Zeroable::zeroed()
    };
    for &alpha in alphas {
@@ -0,0 +1,132 @@
+//! Frames in flight: the readbacks a submission starts, landing frames the submit thread
+//! submitted, keeping offscreen frames at most two ahead of the GPU, and a screenshot's copy.
+
+use super::{Renderer, ScreenshotRequest, copy_frame, screenshot_save, submit};
+
+impl Renderer {
+    /// The frame's readbacks to start right after its submission (on the submit thread when
+    /// the frame goes there): occlusion culling's results (`cull`) and GPU culling's
+    /// statistics. GPU frames leave occlusion culling off, so a frame has one at most.
+    pub(super) fn after_submit(&mut self) -> Option<submit::AfterSubmit> {
+        let cull = self.cull.as_mut().and_then(|c| c.submitted());
+        let gpu = self.gpu_culling.as_mut().and_then(|g| g.submitted());
+        match (cull, gpu) {
+            (Some(c), Some(g)) => Some(Box::new(move || {
+                c();
+                g();
+            })),
+            (Some(c), None) => Some(Box::new(c)),
+            (None, Some(g)) => Some(Box::new(g)),
+            (None, None) => None,
+        }
+    }
+    /// Frame `frame`'s statistics shown, unless a newer frame's are: a CPU frame's as it is
+    /// drawn, a GPU frame's when its counts come back (`GpuCulling::collect`).
+    pub(super) fn show_stats(&mut self, frame: u64, [sections, draws, calls]: [usize; 3]) {
+        if frame > self.stats_frame {
+            self.stats_frame = frame;
+            (
+                self.drawn_sections,
+                self.section_draws,
+                self.section_draw_calls,
+            ) = (sections, draws, calls);
+        }
+    }
+    /// Frames between the last one drawn and the one whose statistics are shown: 0 after a
+    /// CPU frame, one to three in GPU frames, while their counts are on their way back.
+    pub fn stats_lag(&self) -> u64 {
+        self.frame_serial - self.stats_frame
+    }
+    /// Take in the frame the submit thread submitted: start its readbacks and, offscreen,
+    /// keep at most two frames ahead of the GPU, as a frame submitted in place does.
+    pub(super) fn land_frame(&mut self) {
+        let Some(offscreen) = self.deferred.take() else {
+            return;
+        };
+        let submission = self.queue.landed();
+        if let Some(timer) = &mut self.gpu_timer {
+            timer.submitted(&self.queue);
+            timer.collect(&self.device, &mut self.gpu_times);
+        }
+        if let Some(Some(timer)) = Self::pass_timer(&mut self.pack_post, &mut self.native) {
+            timer.submitted(&self.queue);
+        }
+        if let Some(timer) = &mut self.own_timing {
+            timer.submitted(&self.queue);
+        }
+        if offscreen && let Some(submission) = submission {
+            self.in_flight.push_back(submission);
+            if !self.paced_elsewhere {
+                self.wait_frames();
+            }
+        }
+    }
+    /// No swapchain paces offscreen frames: keep two on the GPU at most.
+    pub fn wait_in_flight(&mut self) {
+        self.land_frame();
+        self.wait_frames();
+    }
+    /// The frame on the submit thread submitted: a surface reconfigure waits for the
+    /// device and breaks if a frame is submitted while it waits, and the compositor
+    /// copies views after them. (The end of a frame already lands the frames of the
+    /// turn before; this is the turn's own.)
+    pub fn wait_submissions(&mut self) {
+        self.queue.wait();
+    }
+    pub(super) fn wait_frames(&mut self) {
+        while self.in_flight.len() > 2 {
+            let index = self.in_flight.pop_front();
+            let _ = self.device.poll(wgpu::PollType::Wait {
+                submission_index: index,
+                timeout: Some(std::time::Duration::from_secs(5)),
+            });
+        }
+    }
+    /// Take a screenshot request: queue the frame's copy, or report why the
+    /// frame cannot be read back.
+    pub(super) fn take_readback(
+        &mut self,
+        request: ScreenshotRequest,
+        encoder: &mut wgpu::CommandEncoder,
+        texture: &wgpu::Texture,
+    ) -> Option<(ScreenshotRequest, wgpu::Buffer)> {
+        // The copy and PNG writer both assume 8-bit pixels; a float surface would make
+        // the row stride too small for the copy and abort in validation.
+        if self.config.format.block_copy_size(None) == Some(4) {
+            let size = [self.config.width, self.config.height];
+            let format = self.config.format.remove_srgb_suffix();
+            // The layered float frame maps the world to SDR, then adds the HUD as drawn.
+            // Other 16-bit frames keep their clipped 8-bit copy.
+            let copy = self
+                .hdr
+                .as_mut()
+                .and_then(|hdr| {
+                    hdr.sdr_screenshot(&self.device, encoder, format, request.size.is_some())
+                })
+                .or_else(|| {
+                    (texture.format() != format && texture.format() == self.output.frame.format)
+                        .then(|| {
+                            self.readback
+                                .unorm_copy(&self.device, encoder, texture, format)
+                        })
+                });
+            let texture = copy.as_ref().unwrap_or(texture);
+            Some((request, copy_frame(&self.device, encoder, texture, size)))
+        } else {
+            let error = format!(
+                "screenshots need a 32-bit surface format, not {:?}",
+                self.config.format
+            );
+            if request.background {
+                self.saved_screenshots.push(screenshot_save::Saved {
+                    path: request.path,
+                    result: Err(error),
+                    hdr: None,
+                });
+            } else {
+                self.screenshot_result = Some(Err(error));
+            }
+            None
+        }
+    }
+}
@@ -2770,6 +2770,8 @@ file = \"b.wgsl\"
                true,
            );
            (display.paper_white, display.peak) = (paper, peak);
+            // As the renderer has it under a pack that draws: Horizon lights none of it.
+            display.lighting = false;
            if switched {
                use super::super::hdr::Output::{Pq, ScRgb};
                display = display.retargeted(&device, &queue, ScRgb);
@@ -696,13 +696,16 @@ impl Oit {
            ),
        ] {
            {
-                let mut pass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
+                let pass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
                    label: Some(label),
                    timestamp_writes: timing.as_deref_mut().and_then(|t| t.writes(label)),
                    color_attachments: &first,
                    depth_stencil_attachment: read_only(terrain_depth),
                    ..Default::default()
                });
+                let pixels = super::pixel_count(terrain_depth);
+                let mut pass =
+                    super::pack_timing::counted(timing.as_deref_mut(), pass, pixels, label);
                pass.set_bind_group(GROUP, group, &[]);
                draw(&mut pass, stage);
            }
@@ -0,0 +1,169 @@
+//! The world pass after culling, and the renderer's GPU pass timing switches and readings.
+use super::{Renderer, native_pack, pack_post, pack_timing};
+
+pub(super) fn world_pass_after_culling<'e>(
+    encoder: &'e mut wgpu::CommandEncoder,
+    view: &wgpu::TextureView,
+    depth: &wgpu::TextureView,
+    keep_depth: bool,
+    mut timing: Option<&mut pack_timing::PassTiming>,
+    name: &str,
+    pixels: u64,
+) -> pack_timing::CountedPass<'e> {
+    let pass = after_culling_pass(
+        encoder,
+        view,
+        depth,
+        keep_depth,
+        timing.as_deref_mut().and_then(|t| t.writes(name)),
+    );
+    pack_timing::counted(timing, pass, pixels, "before translucent")
+}
+/// The pixels of a depth attachment, for `fragments_per_pixel`.
+pub(super) fn pixel_count(depth: &wgpu::TextureView) -> u64 {
+    let texture = depth.texture();
+    u64::from(texture.width()) * u64::from(texture.height())
+}
+pub(super) fn after_culling_pass<'e>(
+    encoder: &'e mut wgpu::CommandEncoder,
+    view: &wgpu::TextureView,
+    depth: &wgpu::TextureView,
+    keep_depth: bool,
+    timestamp_writes: Option<wgpu::RenderPassTimestampWrites<'_>>,
+) -> wgpu::RenderPass<'e> {
+    encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
+        label: Some("Horizon world, after culling"),
+        timestamp_writes,
+        color_attachments: &[Some(wgpu::RenderPassColorAttachment {
+            view,
+            resolve_target: None,
+            depth_slice: None,
+            ops: wgpu::Operations {
+                load: wgpu::LoadOp::Load,
+                store: wgpu::StoreOp::Store,
+            },
+        })],
+        depth_stencil_attachment: Some(wgpu::RenderPassDepthStencilAttachment {
+            view: depth,
+            depth_ops: Some(wgpu::Operations {
+                load: wgpu::LoadOp::Load,
+                // A shader pack reads it as depthtex0.
+                store: if keep_depth {
+                    wgpu::StoreOp::Store
+                } else {
+                    wgpu::StoreOp::Discard
+                },
+            }),
+            stencil_ops: None,
+        }),
+        ..Default::default()
+    })
+}
+
+impl Renderer {
+    /// Times the shader pack's passes on the GPU while `on` (the F3 overlay is open or a capture records them).
+    pub fn set_pass_timing(&mut self, on: bool) {
+        self.pass_timing = on;
+    }
+    /// Times the parts of Horizon's own passes while `on`.
+    pub fn set_pass_detail(&mut self, on: bool) {
+        self.pass_detail = on;
+    }
+    /// Times a frame at most once per `gap` while passes are timed (the F3 overlay needs far fewer
+    /// samples than a measurement).
+    pub fn set_pass_timing_gap(&mut self, gap: std::time::Duration) {
+        self.pass_timing_gap = gap;
+    }
+    /// Keeps each timed frame's pass times for `take_timed_frames` while `on` (a capture records them).
+    pub fn set_keep_timed_frames(&mut self, on: bool) {
+        self.keep_timed_frames = on;
+    }
+    /// The frames both timers timed since the last call, without waiting on the GPU.
+    pub fn take_timed_frames(&mut self) -> pack_timing::TimedFrames {
+        let own = self
+            .own_timing
+            .as_mut()
+            .map(pack_timing::PassTiming::take_frames)
+            .unwrap_or_default();
+        let pack = match Self::pass_timer(&mut self.pack_post, &mut self.native) {
+            Some(Some(t)) => t.take_frames(),
+            _ => Vec::new(),
+        };
+        pack_timing::TimedFrames { own, pack }
+    }
+    /// The running shader pack's timer, of either kind.
+    pub(super) fn pass_timer<'a>(
+        pack: &'a mut Option<(i32, Option<pack_post::PackPost>)>,
+        native: &'a mut Option<native_pack::NativePack>,
+    ) -> Option<&'a mut Option<pack_timing::PassTiming>> {
+        match (pack, native) {
+            (Some((_, Some(post))), _) => Some(&mut post.timing),
+            (_, Some(native)) => Some(&mut native.timing),
+            _ => None,
+        }
+    }
+    /// Each pass of the running shader pack with its median GPU time in milliseconds, while
+    /// they are timed (`set_pass_timing`).
+    pub fn shader_pass_times(&self) -> Vec<(String, f32)> {
+        let timer = match (&self.pack_post, &self.native) {
+            (Some((_, Some(post))), _) => post.timing.as_ref(),
+            (_, Some(native)) => native.timing.as_ref(),
+            _ => None,
+        };
+        timer
+            .map(pack_timing::PassTiming::medians)
+            .unwrap_or_default()
+    }
+    /// Each of Horizon's own passes with its median GPU time in milliseconds, while they are
+    /// timed (`set_pass_timing`).
+    pub fn own_pass_times(&self) -> Vec<(String, f32)> {
+        self.own_timing
+            .as_ref()
+            .map(pack_timing::PassTiming::medians)
+            .unwrap_or_default()
+    }
+    /// Each of Horizon's own passes with its parts' median GPU times in milliseconds.
+    pub fn own_pass_parts(&self) -> Vec<(String, Vec<(String, f32)>)> {
+        self.own_timing
+            .as_ref()
+            .map(pack_timing::PassTiming::part_medians)
+            .unwrap_or_default()
+    }
+    /// Each counted pass's counters (medians), while detail is on and the device has them.
+    pub fn own_pass_counters(&self) -> Vec<(String, pack_timing::PassCounters)> {
+        self.own_timing
+            .as_ref()
+            .map(pack_timing::PassTiming::counter_medians)
+            .unwrap_or_default()
+    }
+    /// Both timers' readings and this adapter, for a capture; `None` when neither has timed a pass.
+    pub fn gpu_readout(&self) -> Option<pack_timing::GpuReadout> {
+        let own = self
+            .own_timing
+            .as_ref()
+            .map(pack_timing::PassTiming::readings)
+            .filter(|r| !r.is_empty());
+        let pack = match (&self.pack_post, &self.native) {
+            (Some((_, Some(post))), _) => post.timing.as_ref(),
+            (_, Some(native)) => native.timing.as_ref(),
+            _ => None,
+        }
+        .map(pack_timing::PassTiming::readings)
+        .filter(|r| !r.is_empty());
+        (own.is_some() || pack.is_some()).then(|| pack_timing::GpuReadout {
+            adapter: self.info.clone(),
+            own,
+            pack,
+        })
+    }
+    /// Whether dispatch parts and counters are being asked for (`set_pass_detail`).
+    pub fn pass_detail(&self) -> bool {
+        self.pass_detail
+    }
+    /// What detail timing can show on this device; `None` without pass timing.
+    pub fn pass_detail_support(&self) -> Option<pack_timing::DetailSupport> {
+        self.own_timing
+            .as_ref()
+            .map(pack_timing::PassTiming::detail_support)
+    }
+}
@@ -47,7 +47,7 @@ struct Uniform {
    clip_from_sky: [[f32; 4]; 4],
    color: [f32; 4],
    hdr_settings: [f32; 4],
-    hdr_shares: [f32; 4],
+    hdr_gains: [f32; 4],
    hdr_light: [f32; 4],
 }

@@ -184,7 +184,7 @@ impl Stars {
            clip_from_sky: clip_from_sky.to_cols_array_2d(),
            color: [b; 4],
            hdr_settings: globals.hdr_settings,
-            hdr_shares: globals.hdr_shares,
+            hdr_gains: globals.hdr_gains,
            hdr_light: globals.hdr_light,
        };
        uploads.buffer(encoder, &self.uniform, 0, bytemuck::bytes_of(&uniform));
@@ -5,7 +5,7 @@ struct Stars {
    // starBrightness in every channel (RenderSystem.setShaderColor).
    color: vec4<f32>,
    hdr_settings: vec4<f32>,
-    hdr_shares: vec4<f32>,
+    hdr_gains: vec4<f32>,
    hdr_light: vec4<f32>,
 }
@group(0) @binding(0) var<uniform> stars: Stars;
@@ -20,7 +20,7 @@ struct Stars {
@fragment fn fs_stars() -> @location(0) vec4<f32> {
    let b = stars.color.a;
    if HDR_WRITE_LIGHT && stars.hdr_light.w != 0.0 {
-        return vec4(hdr_written(stars.color.rgb * b, 0.175, stars.hdr_settings, stars.hdr_shares), b);
+        return vec4(hdr_written(stars.color.rgb * b, 0.175, stars.hdr_settings, stars.hdr_gains), b);
    }
    if HDR_WRITE_LIGHT { return vec4(frame_stored(stars.color).rgb * b, b); }
    return vec4(stars.color.rgb * b, 0.175);
@@ -2,8 +2,8 @@
 //! an adapter that can't present to the window gives way to another of its backend
 //! (#13493).
 use super::{
-    Renderer, check_layers, cull, describe_adapter, is_software, oit, startup_step, surface_format,
-    timing,
+    Renderer, check_layers, cull, describe_adapter, is_software, oit, pack_timing, startup_step,
+    surface_format, timing,
 };
 // Ray tracing on request, which the device needs from its creation (gfx.rs may not grow).
 #[path = "ray_query.rs"]
@@ -135,6 +135,7 @@ pub(super) async fn open_adapter(
    // atomics on images: their buffers and images. Filtering 32-bit float textures: shader
    // packs' RGBA32F buffers, which GL filters and mipmaps. Count draws: GPU culling's (`gpu_culling`).
    let features = timing::GpuTimer::features(adapter)
+        | pack_timing::PassTiming::features(adapter)
        | cull::Cull::features(adapter)
        | oit::features(adapter)
        | ray_query::features(adapter)
@@ -0,0 +1,252 @@
+//! The camera's view frustum, as camera-relative clip planes.
+
+use glam::{Vec3, Vec4};
+
+/// Camera-relative clip planes (`Frustum`).
+#[derive(Clone, Copy, Debug)]
+pub struct Frustum {
+    pub(super) planes: [Vec4; 6],
+}
+impl Frustum {
+    /// Whether the camera-relative box `min..max` is at least partly inside.
+    pub fn intersects(&self, min: Vec3, max: Vec3) -> bool {
+        !self.planes.iter().any(|p| {
+            let sign = p.truncate().cmpge(Vec3::ZERO);
+            let v = Vec3::select(sign, max, min);
+            p.truncate().dot(v) + p.w < 0.0
+        })
+    }
+    /// Whether a camera-relative sphere is at least partly inside. Frustum
+    /// planes are normalized, so each test needs only one dot product and a
+    /// radius comparison.
+    pub fn intersects_sphere(&self, center: Vec3, radius: f32) -> bool {
+        if !center.is_finite() || !radius.is_finite() || radius < 0.0 {
+            return true;
+        }
+        !self
+            .planes
+            .iter()
+            .any(|plane| plane.truncate().dot(center) + plane.w < -radius)
+    }
+    /// Depth clip planes alone: X/Y projection jitter cannot change this test.
+    /// Retaining side-of-screen geometry makes this safe before TAA selects a phase.
+    pub fn intersects_depth(&self, min: Vec3, max: Vec3) -> bool {
+        if !min.is_finite() || !max.is_finite() || !min.cmple(max).all() {
+            return true;
+        }
+        !self.planes[4..].iter().any(|p| {
+            let sign = p.truncate().cmpge(Vec3::ZERO);
+            let v = Vec3::select(sign, max, min);
+            p.truncate().dot(v) + p.w < 0.0
+        })
+    }
+    /// Whether the camera-relative box `min..max` is entirely inside. Then
+    /// `intersects` accepts every box within it: each plane's distance only
+    /// grows from this box's nearest corner to the inner box's farthest, and
+    /// rounding keeps that order.
+    pub fn contains(&self, min: Vec3, max: Vec3) -> bool {
+        self.planes.iter().all(|p| {
+            let sign = p.truncate().cmpge(Vec3::ZERO);
+            let v = Vec3::select(sign, min, max);
+            p.truncate().dot(v) + p.w >= 0.0
+        })
+    }
+    /// Whether the camera-relative `point` is on or inside every plane (vanilla's
+    /// `Frustum.pointInFrustum`). A point that is not finite is kept: a test that cannot
+    /// tell must not hide the particle.
+    pub fn contains_point(&self, point: Vec3) -> bool {
+        if !point.is_finite() {
+            return true;
+        }
+        self.planes
+            .iter()
+            .all(|plane| plane.truncate().dot(point) + plane.w >= 0.0)
+    }
+    /// The same frustum seen from a camera moved `blocks` back along the view direction
+    /// (vanilla's `Frustum.offset`): the sides open up near the camera and the near plane
+    /// moves behind it, so what sits just behind or beside the camera stays inside.
+    ///
+    /// The view direction is the normal of the depth planes (the two are opposite), signed
+    /// towards where the side planes point. A frustum that has no direction to pull along
+    /// comes back unchanged: a box with no depth planes (the shadow pass's), and a box whose
+    /// sides are parallel to the view direction (an orthographic projection), where the side
+    /// normals cancel and say nothing about which way is forward.
+    pub fn pulled_back(&self, blocks: f32) -> Frustum {
+        let sides: Vec3 = self.planes[..4].iter().map(|p| p.truncate()).sum();
+        let depth = self.planes[4].truncate();
+        let along = depth.dot(sides);
+        // A perspective frustum's four side normals each lean forward, so this is well above 1.
+        if along.abs() < 1.0e-3 {
+            return *self;
+        }
+        let toward_sides = if along > 0.0 { depth } else { -depth };
+        let axis = toward_sides.normalize_or_zero();
+        let mut planes = self.planes;
+        for plane in &mut planes {
+            plane.w += blocks * plane.truncate().dot(axis);
+        }
+        Frustum { planes }
+    }
+    /// The frustum of a camera-relative `view_proj`, for tests outside this module.
+    #[cfg(test)]
+    pub(crate) fn from_view_projection(view_proj: glam::Mat4) -> Frustum {
+        Frustum {
+            planes: super::frustum(view_proj),
+        }
+    }
+}
+#[cfg(test)]
+mod tests {
+    use super::{Frustum, Vec3};
+    use crate::gfx::world_projection;
+    use glam::Mat4;
+
+    const FOV: f32 = 70.0;
+    const ASPECT: f32 = 16.0 / 9.0;
+    const FAR: f32 = 512.0;
+    const EPS: f32 = 0.01;
+
+    fn looking_down_minus_z() -> Frustum {
+        Frustum::from_view_projection(world_projection(FOV, ASPECT, FAR))
+    }
+
+    fn tangents() -> (f32, f32) {
+        let up = (FOV / 2.0).to_radians().tan();
+        (up * ASPECT, up)
+    }
+
+    /// Each of the six planes of the unmoved frustum, a point just inside and one just outside,
+    /// from the field of view worked out by hand.
+    #[test]
+    fn a_point_is_inside_only_within_all_six_planes() {
+        let view = looking_down_minus_z();
+        let (tan_x, tan_y) = tangents();
+        let depth = 10.0;
+        let inside = [
+            Vec3::new(0.0, 0.0, -depth),
+            Vec3::new(depth * tan_x - EPS, 0.0, -depth),
+            Vec3::new(-(depth * tan_x - EPS), 0.0, -depth),
+            Vec3::new(0.0, depth * tan_y - EPS, -depth),
+            Vec3::new(0.0, -(depth * tan_y - EPS), -depth),
+            Vec3::new(0.0, 0.0, -0.06),
+            Vec3::new(0.0, 0.0, -(FAR - 0.1)),
+        ];
+        let outside = [
+            Vec3::new(depth * tan_x + EPS, 0.0, -depth),
+            Vec3::new(-(depth * tan_x + EPS), 0.0, -depth),
+            Vec3::new(0.0, depth * tan_y + EPS, -depth),
+            Vec3::new(0.0, -(depth * tan_y + EPS), -depth),
+            Vec3::new(0.0, 0.0, -0.04),
+            Vec3::new(0.0, 0.0, -(FAR + 0.1)),
+            Vec3::new(0.0, 0.0, 1.0),
+            Vec3::new(0.0, 0.0, 0.0),
+        ];
+        for p in inside {
+            assert!(view.contains_point(p), "{p} should be inside");
+        }
+        for p in outside {
+            assert!(!view.contains_point(p), "{p} should be outside");
+        }
+        assert!(view.contains_point(Vec3::NAN), "an unknown point is kept");
+    }
+
+    /// Camera 3 blocks back: its apex is at z = 3, so the sides open by 3 * tan, the near
+    /// plane is at z = 3 - 0.05 and the far plane at z = 3 - FAR.
+    #[test]
+    fn pulling_the_camera_back_moves_every_plane() {
+        let (tan_x, tan_y) = tangents();
+        let back = looking_down_minus_z().pulled_back(3.0);
+        let inside = [
+            Vec3::new(0.0, 0.0, 2.9),
+            Vec3::new(3.0 * tan_x - EPS, 0.0, 0.0),
+            Vec3::new(-(3.0 * tan_x - EPS), 0.0, 0.0),
+            Vec3::new(0.0, 3.0 * tan_y - EPS, 0.0),
+            Vec3::new(0.0, -(3.0 * tan_y - EPS), 0.0),
+            Vec3::new(0.0, 0.0, 3.0 - FAR + 0.1),
+        ];
+        let outside = [
+            Vec3::new(0.0, 0.0, 3.0),
+            Vec3::new(3.0 * tan_x + EPS, 0.0, 0.0),
+            Vec3::new(-(3.0 * tan_x + EPS), 0.0, 0.0),
+            Vec3::new(0.0, 3.0 * tan_y + EPS, 0.0),
+            Vec3::new(0.0, -(3.0 * tan_y + EPS), 0.0),
+            Vec3::new(0.0, 0.0, 3.0 - FAR - 0.1),
+        ];
+        for p in inside {
+            assert!(back.contains_point(p), "{p} should be inside");
+        }
+        for p in outside {
+            assert!(!back.contains_point(p), "{p} should be outside");
+        }
+        // The unmoved frustum does not have the point that only the offset one has.
+        assert!(!looking_down_minus_z().contains_point(Vec3::new(0.0, 0.0, 2.9)));
+        // An offset of nothing changes no verdict.
+        let same = looking_down_minus_z();
+        let unmoved = same.pulled_back(0.0);
+        for p in [
+            Vec3::new(1.0, 2.0, -3.0),
+            Vec3::new(0.0, 0.0, 1.0),
+            Vec3::new(40.0, 0.0, -5.0),
+        ] {
+            assert_eq!(same.contains_point(p), unmoved.contains_point(p));
+        }
+    }
+
+    /// The offset follows the camera's own view direction, whatever way it looks.
+    #[test]
+    fn the_offset_is_along_the_view_direction() {
+        for (yaw, pitch) in [(0.3_f32, 0.0_f32), (2.0, -0.5), (-1.2, 0.9), (3.0, 1.2)] {
+            let pose = Mat4::from_rotation_x(pitch) * Mat4::from_rotation_y(yaw);
+            let view = Frustum::from_view_projection(world_projection(FOV, ASPECT, FAR) * pose);
+            let forward = pose.inverse().transform_vector3(-Vec3::Z);
+            let back = view.pulled_back(3.0);
+            assert!(
+                back.contains_point(forward * -2.9),
+                "{yaw} {pitch}: 2.9 behind"
+            );
+            assert!(
+                !back.contains_point(forward * -3.0),
+                "{yaw} {pitch}: 3 behind"
+            );
+            assert!(
+                !view.contains_point(forward * -2.9),
+                "{yaw} {pitch}: unmoved"
+            );
+            assert!(back.contains_point(forward * 20.0) && view.contains_point(forward * 20.0));
+        }
+    }
+
+    /// An orthographic box has no apex to pull back from: its side normals cancel, so there is
+    /// no direction, and the frustum must come back as it was.
+    #[test]
+    fn an_orthographic_frustum_stays_where_it_is() {
+        let ortho =
+            Frustum::from_view_projection(Mat4::orthographic_rh(-8.0, 8.0, -4.5, 4.5, 100.0, 0.05));
+        let moved = ortho.pulled_back(3.0);
+        for p in [
+            Vec3::new(0.0, 0.0, 2.0),
+            Vec3::new(0.0, 0.0, -9.0),
+            Vec3::new(7.9, 4.4, -9.0),
+            Vec3::new(8.1, 0.0, -9.0),
+            Vec3::new(0.0, 0.0, -101.0),
+        ] {
+            assert_eq!(ortho.contains_point(p), moved.contains_point(p), "{p}");
+        }
+    }
+
+    /// The shadow pass's box has no depth planes, so no direction: it must not move.
+    #[test]
+    fn a_frustum_without_depth_planes_stays_where_it_is() {
+        let mut flat = looking_down_minus_z();
+        flat.planes[4] = glam::Vec4::W;
+        flat.planes[5] = glam::Vec4::W;
+        let moved = flat.pulled_back(3.0);
+        for p in [
+            Vec3::new(0.0, 0.0, 2.0),
+            Vec3::new(0.0, 0.0, -9.0),
+            Vec3::new(80.0, 0.0, -9.0),
+        ] {
+            assert_eq!(flat.contains_point(p), moved.contains_point(p));
+        }
+    }
+}
@@ -239,17 +239,17 @@ impl Visbuffer {
        encoder: &'e mut wgpu::CommandEncoder,
        depth: &wgpu::TextureView,
        clear: bool,
-        timing: Option<&mut PassTiming>,
-    ) -> wgpu::RenderPass<'e> {
+        mut timing: Option<&mut PassTiming>,
+    ) -> super::pack_timing::CountedPass<'e> {
        let (ids, _) = self.ids.as_ref().expect("fitted before the world pass");
        let name = if clear {
            "Visibility IDs"
        } else {
            "Visibility IDs after culling"
        };
-        encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
+        let pass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
            label: Some("Horizon visibility buffer"),
-            timestamp_writes: timing.and_then(|t| t.writes(name)),
+            timestamp_writes: timing.as_deref_mut().and_then(|t| t.writes(name)),
            color_attachments: &[Some(wgpu::RenderPassColorAttachment {
                view: ids,
                resolve_target: None,
@@ -272,7 +272,8 @@ impl Visbuffer {
                stencil_ops: None,
            }),
            ..Default::default()
-        })
+        });
+        super::pack_timing::counted(timing, pass, super::pixel_count(depth), name)
    }

    /// Phase 1's solid calls into the IDs, as the normal passes draw them: the opaque
@@ -360,13 +360,13 @@ impl Post {
        &mut self,
        gain: bool,
        settings: [f32; 4],
-        shares: [f32; 4],
+        gains: [f32; 4],
        windows: [[f32; 4]; 2],
    ) {
        // These uniforms do not change baked colour without gain. Keep compatibility
        // history stable when only its final display settings change.
        let key = Some(if gain {
-            (true, settings, shares, windows)
+            (true, settings, gains, windows)
        } else {
            (false, [0.0; 4], [0.0; 4], [[0.0; 4]; 2])
        });
@@ -887,7 +887,7 @@ mod tests {
        post.jitter([32, 32], true, Mat4::IDENTITY, DVec3::ZERO);
        assert_eq!(post.taa_this_frame.jitter[2], 0.0);
        eprintln!(
-            "TAA baked-light GPU checked gain, all settings/shares/windows and the first frame after a pack"
+            "TAA baked-light GPU checked gain, all settings/gains/windows and the first frame after a pack"
        );
    }

@@ -64,7 +64,7 @@ fn warp_fragment(in: TerrainOut, front: bool) -> Fragment {
        let fog = max(linear_fog(in.spherical, globals.fog.x, globals.fog.y),
            linear_fog(in.cylindrical, globals.fog.z, globals.fog.w)) * globals.fog_color.a;
        let mark = hdr_scene_alpha(mix(hdr_scene(in.scene.x, in.scene.y, hdr_facing()), globals.hdr_light.y, fog));
-        return vec4(hdr_written(finished.rgb, mark, globals.hdr_settings, globals.hdr_shares), finished.a);
+        return vec4(hdr_written(finished.rgb, mark, globals.hdr_settings, globals.hdr_gains), finished.a);
    }
    return frame_stored(finished);
 }
@@ -90,6 +90,8 @@ fn nits_setting(nits: u32) -> u32 {
 /// Simple-level presets. `Custom` leaves every option as the player set it.
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Default)]
 pub enum Preset {
+    /// Every saving on, over the lowest settings (`preset::table`).
+    FullPerformance,
    Performance,
    Balanced,
    Quality,
@@ -98,7 +100,8 @@ pub enum Preset {
    Custom,
 }
 impl Preset {
-    pub const ALL: [Preset; 5] = [
+    pub const ALL: [Preset; 6] = [
+        Preset::FullPerformance,
        Preset::Performance,
        Preset::Balanced,
        Preset::Quality,
@@ -107,6 +110,7 @@ impl Preset {
    ];
    pub fn name(self) -> &'static str {
        match self {
+            Preset::FullPerformance => "full_performance",
            Preset::Performance => "performance",
            Preset::Balanced => "balanced",
            Preset::Quality => "quality",
@@ -116,6 +120,7 @@ impl Preset {
    }
    pub fn label(self) -> &'static str {
        match self {
+            Preset::FullPerformance => "Full Performance",
            Preset::Performance => "Performance",
            Preset::Balanced => "Balanced",
            Preset::Quality => "Quality",
@@ -586,6 +591,45 @@ pub fn translucent_batching_offered() -> bool {
    TRANSLUCENT_BATCHING_OFFERED.load(std::sync::atomic::Ordering::Relaxed)
 }

+/// Parallel Tick's setting, for the worlds this game runs itself (single player, open to LAN):
+/// whether the server tick's phases that give the same result in any order share their work
+/// among helper threads (`parallel`). Auto shares it only while the tick is heavy and sharing
+/// makes it faster; a quiet world stays on one thread and starts no helper.
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Default)]
+pub enum ParallelTickMode {
+    #[default]
+    Off = 0,
+    Auto = 1,
+    On = 2,
+}
+impl ParallelTickMode {
+    pub const ALL: [ParallelTickMode; 3] = [
+        ParallelTickMode::Off,
+        ParallelTickMode::Auto,
+        ParallelTickMode::On,
+    ];
+    pub fn name(self) -> &'static str {
+        match self {
+            Self::Off => "off",
+            Self::Auto => "auto",
+            Self::On => "on",
+        }
+    }
+    pub fn label(self) -> &'static str {
+        match self {
+            Self::Off => "Off",
+            Self::Auto => "Auto",
+            Self::On => "On",
+        }
+    }
+    fn parse(s: &str) -> Self {
+        Self::ALL
+            .into_iter()
+            .find(|m| m.name() == s)
+            .unwrap_or_default()
+    }
+}
+
 /// GPU Culling's setting: off, on where it is offered, or Auto, which has it on only where the
 /// CPU limits the frame and it makes the frame faster (`autotune::GpuCullingAuto`).
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Default)]
@@ -773,9 +817,9 @@ pub struct Graphics {
    pub cave_culling: bool,
    /// Near solid terrain culled, and its draws listed, on the GPU (`gfx::gpu_culling`), where it
    /// is offered (`gpu_culling_offer`). Off by default (GPU Culling, Performance graphics); it
-    /// applies at once, and no preset sets it. Every save writes it, so a default turned on later
-    /// needs a new key, as `batchTranslucent` did. Auto turns it on only where the CPU limits the
-    /// frame and it makes the frame faster (`autotune`).
+    /// applies at once, and every preset sets it to Auto. Every save writes it, so a default
+    /// turned on later needs a new key, as `batchTranslucent` did. Auto turns it on only where
+    /// the CPU limits the frame and it makes the frame faster (`autotune`).
    pub gpu_culling: GpuCullingMode,
    /// Skip drawing entities hidden behind opaque terrain, synchronously or asynchronously.
    pub entity_culling: EntityCullingMode,
@@ -821,6 +865,9 @@ pub struct Graphics {
    pub pacing: Pacing,
    /// Chunk worker threads; 0 uses every core but one. Applies at the next start.
    pub workers: u32,
+    /// Parallel Tick (Performance graphics, beside Worker Threads): applies from the next tick,
+    /// and no preset sets it.
+    pub parallel_tick: ParallelTickMode,
    pub overlay: Overlay,
    /// World resolution as a percentage of the window's (50..=200).
    pub resolution_scale: u32,
@@ -923,6 +970,7 @@ impl Default for Graphics {
            present_mode: PresentMode::Auto,
            pacing: Pacing::Efficient,
            workers: 0,
+            parallel_tick: ParallelTickMode::Off,
            overlay: Overlay::Off,
            resolution_scale: 100,
            dynamic_resolution: false,
@@ -1045,6 +1093,7 @@ impl Graphics {
                "particleCulling" => g.particle_culling = ParticleCullingMode::parse(value),
                "leafCulling" => g.leaf_culling = LeafCullingMode::parse(value),
                "opaqueIce" => g.opaque_ice = flag(g.opaque_ice),
+                "parallelTick" => g.parallel_tick = ParallelTickMode::parse(value),
                "blockEntityCache" => {
                    let enabled = flag(false);
                    g.cache_shulker_boxes = enabled;
@@ -1144,7 +1193,7 @@ impl Graphics {
    }
    pub fn serialize(&self) -> String {
        let mut text = format!(
-            "preset:{}\nlodDistance:{}\nfarDetail:{}\ncaveCulling:{}\nentityCulling:{}\nentityCullingPrecheck:{}\nparticleCulling:{}\nleafCulling:{}\nopaqueIce:{}\nblockEntityCacheShulkerBoxes:{}\nblockEntityCacheSigns:{}\nblockEntityCacheDecoratedPots:{}\nblockEntityCacheBells:{}\nblockEntityCacheChests:{}\nblockEntityCacheBanners:{}\nblockEntityCacheCopperGolemStatues:{}\nchunkUpdates:{}\nuploadBudgetKiB:{}\ntextureBudgetMiB:{}\nsky:{}\nfog:{}\nweather:{}\nanimatedTextures:{}\nditherCutoutMips:{}\npresentMode:{}\nframePacing:{}\nworkers:{}\noverlay:{}\nresolutionScale:{}\ndynamicResolution:{}\ntargetFps:{}\nfxaa:{}\ntaa:{}\nupscaling:{}\nupscalingSharpness:{}\nscreenshotQuality:{}\nframeGeneration:{}\nhdr:{}\nhdrPaperWhite:{}\nhdrPeak:{}\nhdrBlackLevel:{}\nhdrUiNits:{}\nhdrLighting:{}\nbatteryMode:{}\nshadowCache:{}\ngraphicsApi:{}\npickedShaderPack:{}\nbatchTranslucent:{}\nhdrSmoothGradients:{}\ngpuCulling:{}\n",
+            "preset:{}\nlodDistance:{}\nfarDetail:{}\ncaveCulling:{}\nentityCulling:{}\nentityCullingPrecheck:{}\nparticleCulling:{}\nleafCulling:{}\nopaqueIce:{}\nblockEntityCacheShulkerBoxes:{}\nblockEntityCacheSigns:{}\nblockEntityCacheDecoratedPots:{}\nblockEntityCacheBells:{}\nblockEntityCacheChests:{}\nblockEntityCacheBanners:{}\nblockEntityCacheCopperGolemStatues:{}\nchunkUpdates:{}\nuploadBudgetKiB:{}\ntextureBudgetMiB:{}\nsky:{}\nfog:{}\nweather:{}\nanimatedTextures:{}\nditherCutoutMips:{}\npresentMode:{}\nframePacing:{}\nworkers:{}\noverlay:{}\nresolutionScale:{}\ndynamicResolution:{}\ntargetFps:{}\nfxaa:{}\ntaa:{}\nupscaling:{}\nupscalingSharpness:{}\nscreenshotQuality:{}\nframeGeneration:{}\nhdr:{}\nhdrPaperWhite:{}\nhdrPeak:{}\nhdrBlackLevel:{}\nhdrUiNits:{}\nhdrLighting:{}\nbatteryMode:{}\nshadowCache:{}\ngraphicsApi:{}\npickedShaderPack:{}\nbatchTranslucent:{}\nhdrSmoothGradients:{}\ngpuCulling:{}\nparallelTick:{}\n",
            self.preset.name(),
            self.lod_distance,
            self.far_detail.name(),
@@ -1202,6 +1251,7 @@ impl Graphics {
            bool_text(self.translucent_batching),
            bool_text(self.hdr_smooth_gradients),
            self.gpu_culling.key(),
+            self.parallel_tick.name(),
        );
        if let Some(driver) = &self.hdr_failed_start {
            text += &format!("hdrFailedStart:{driver}\n");
@@ -1280,37 +1330,9 @@ impl Graphics {
    }
 }

-/// A preset's values for vanilla's options and Horizon's own.
-pub fn apply_preset(preset: Preset, s: &mut crate::settings::Settings) {
-    let (rd, sim, clouds, particles, shadows, blend, mipmaps, entity, leaves, weather_r) =
-        match preset {
-            Preset::Performance => (8, 6, "false", 2, false, 0, 0, 0.5, false, 3),
-            Preset::Balanced => (12, 8, "fast", 1, true, 1, 2, 0.75, true, 5),
-            Preset::Quality => (16, 12, "true", 0, true, 2, 4, 1.0, true, 10),
-            Preset::Ultra => (24, 12, "true", 0, true, 3, 4, 1.5, true, 10),
-            Preset::Custom => return,
-        };
-    s.render_distance = rd;
-    s.simulation_distance = sim;
-    s.clouds = clouds.into();
-    s.particles = particles;
-    s.entity_shadows = shadows;
-    s.biome_blend = blend;
-    s.mipmap_levels = mipmaps;
-    s.entity_distance = entity;
-    s.cutout_leaves = leaves;
-    s.weather_radius = weather_r;
-    s.graphics_preset = "custom".into();
-    let g = &mut s.horizon;
-    g.preset = preset;
-    g.cave_culling = true;
-    g.animated_textures = true;
-    g.chunk_updates = 0;
-    g.upload_budget_kib = 0;
-    g.sky = true;
-    g.fog = true;
-    g.weather = true;
-}
+#[path = "graphics_preset.rs"]
+mod preset;
+pub use preset::apply_preset;

 #[cfg(test)]
 mod tests {
@@ -1546,6 +1568,7 @@ mod tests {
            present_mode: PresentMode::Mailbox,
            pacing: Pacing::Precise,
            workers: 6,
+            parallel_tick: ParallelTickMode::Auto,
            overlay: Overlay::Graph,
            resolution_scale: 75,
            dynamic_resolution: false,
@@ -0,0 +1,169 @@
+//! The graphics presets: each one a fixed table of the options it sets, vanilla's and
+//! Horizon's own, so that picking one gives the same settings whatever was set before.
+//! Every preset turns on the optimizations that leave the picture as it is; Full
+//! Performance adds the ones that change it. What no table names keeps the player's
+//! choice: the display preferences (`graphics_ui`'s `touched`), Far Detail and Leaf
+//! Culling, which follow the machine and the look the player picked, and Translucent
+//! Batching, on unless the player turned it off.
+use super::{EntityCullingMode, GpuCullingMode, ParticleCullingMode, Preset, Upscaling};
+use crate::settings::Settings;
+
+/// What differs between the presets. Every one of them also turns on entity and particle
+/// culling on a worker, the block-entity caches and GPU Culling's Auto (which tries it only
+/// where it makes frames faster), keeps cave culling, the sky, the fog, the weather and the
+/// animated textures on, uploads meshes unthrottled and draws at a fixed resolution without
+/// TAA.
+struct Table {
+    render_distance: i32,
+    simulation_distance: i32,
+    /// `options.txt`'s `renderClouds`: `false`, `fast` or `true`.
+    clouds: &'static str,
+    /// 0 all, 1 decreased, 2 minimal.
+    particles: u8,
+    entity_shadows: bool,
+    biome_blend: i32,
+    mipmap_levels: i32,
+    entity_distance: f32,
+    cutout_leaves: bool,
+    weather_radius: i32,
+    /// Far terrain's range in chunks; 0 is off.
+    lod_distance: u32,
+    opaque_ice: bool,
+    resolution_scale: u32,
+    fxaa: bool,
+    dither_cutout_mips: bool,
+}
+
+fn table(preset: Preset) -> Option<Table> {
+    Some(match preset {
+        Preset::FullPerformance => Table {
+            render_distance: 6,
+            simulation_distance: 5,
+            clouds: "false",
+            particles: 2,
+            entity_shadows: false,
+            biome_blend: 0,
+            mipmap_levels: 0,
+            entity_distance: 0.5,
+            cutout_leaves: false,
+            weather_radius: 3,
+            lod_distance: 0,
+            opaque_ice: true,
+            resolution_scale: 75,
+            fxaa: false,
+            dither_cutout_mips: false,
+        },
+        Preset::Performance => Table {
+            render_distance: 8,
+            simulation_distance: 6,
+            clouds: "false",
+            particles: 2,
+            entity_shadows: false,
+            biome_blend: 0,
+            mipmap_levels: 0,
+            entity_distance: 0.5,
+            cutout_leaves: false,
+            weather_radius: 3,
+            lod_distance: 0,
+            opaque_ice: false,
+            resolution_scale: 100,
+            fxaa: false,
+            dither_cutout_mips: false,
+        },
+        Preset::Balanced => Table {
+            render_distance: 12,
+            simulation_distance: 8,
+            clouds: "fast",
+            particles: 1,
+            entity_shadows: true,
+            biome_blend: 1,
+            mipmap_levels: 2,
+            entity_distance: 0.75,
+            cutout_leaves: true,
+            weather_radius: 5,
+            lod_distance: 0,
+            opaque_ice: false,
+            resolution_scale: 100,
+            fxaa: false,
+            dither_cutout_mips: false,
+        },
+        Preset::Quality => Table {
+            render_distance: 16,
+            simulation_distance: 12,
+            clouds: "true",
+            particles: 0,
+            entity_shadows: true,
+            biome_blend: 2,
+            mipmap_levels: 4,
+            entity_distance: 1.0,
+            cutout_leaves: true,
+            weather_radius: 10,
+            lod_distance: 64,
+            opaque_ice: false,
+            resolution_scale: 100,
+            fxaa: true,
+            dither_cutout_mips: false,
+        },
+        Preset::Ultra => Table {
+            render_distance: 24,
+            simulation_distance: 12,
+            clouds: "true",
+            particles: 0,
+            entity_shadows: true,
+            biome_blend: 3,
+            mipmap_levels: 4,
+            entity_distance: 1.5,
+            cutout_leaves: true,
+            weather_radius: 10,
+            lod_distance: 128,
+            opaque_ice: false,
+            resolution_scale: 100,
+            fxaa: true,
+            dither_cutout_mips: true,
+        },
+        Preset::Custom => return None,
+    })
+}
+
+/// Sets what `preset`'s table names, in vanilla's options and Horizon's own.
+pub fn apply_preset(preset: Preset, s: &mut Settings) {
+    let Some(t) = table(preset) else { return };
+    s.render_distance = t.render_distance;
+    s.simulation_distance = t.simulation_distance;
+    s.clouds = t.clouds.into();
+    s.particles = t.particles;
+    s.entity_shadows = t.entity_shadows;
+    s.biome_blend = t.biome_blend;
+    s.mipmap_levels = t.mipmap_levels;
+    s.entity_distance = t.entity_distance;
+    s.cutout_leaves = t.cutout_leaves;
+    s.weather_radius = t.weather_radius;
+    s.graphics_preset = "custom".into();
+    let g = &mut s.horizon;
+    g.preset = preset;
+    g.lod_distance = t.lod_distance;
+    g.cave_culling = true;
+    g.gpu_culling = GpuCullingMode::Auto;
+    g.entity_culling = EntityCullingMode::Asynchronous;
+    g.particle_culling = ParticleCullingMode::Asynchronous;
+    g.opaque_ice = t.opaque_ice;
+    g.cache_shulker_boxes = true;
+    g.cache_signs = true;
+    g.cache_decorated_pots = true;
+    g.cache_bells = true;
+    g.cache_chests = true;
+    g.cache_banners = true;
+    g.cache_copper_golem_statues = true;
+    g.chunk_updates = 0;
+    g.upload_budget_kib = 0;
+    g.sky = true;
+    g.fog = true;
+    g.weather = true;
+    g.animated_textures = true;
+    g.dither_cutout_mips = t.dither_cutout_mips;
+    g.resolution_scale = t.resolution_scale;
+    g.dynamic_resolution = false;
+    g.fxaa = t.fxaa;
+    g.taa = false;
+    g.upscaling = Upscaling::Native;
+}
@@ -8,8 +8,8 @@ use crate::{
    gfx::EffectiveOutput,
    graphics::{
        EntityCullingMode, FarDetail, FrameGeneration, GpuCullingMode, GraphicsApi, HdrMode,
-        HdrSetup as Setup, LeafCullingMode, Overlay, Pacing, ParticleCullingMode, PresentMode,
-        Preset, Upscaling,
+        HdrSetup as Setup, LeafCullingMode, Overlay, Pacing, ParallelTickMode, ParticleCullingMode,
+        PresentMode, Preset, Upscaling,
    },
    graphics_style::Cost,
    lang,
@@ -98,6 +98,7 @@ pub enum H {
    PresentMode,
    Pacing,
    Workers,
+    ParallelTick,
    Overlay,
    ResolutionScale,
    DynamicResolution,
@@ -433,6 +434,11 @@ pub fn rows() -> Vec<(Page, Vec<(&'static str, Vec<Setting>)>)> {
                            None,
                            "Threads that generate, light and mesh chunks. Next start.",
                        ),
+                        h(
+                            H::ParallelTick,
+                            Saves,
+                            "Shares your world's tick among threads. Auto: only while that is faster.",
+                        ),
                    ],
                ),
                (
@@ -853,7 +859,7 @@ impl H {
    fn label(self, s: &Settings, out: &EffectiveOutput) -> Text {
        let g = &s.horizon;
        match self {
-            H::Preset => labelled("Preset", g.preset.label()),
+            H::Preset => labelled("Horizon Preset", g.preset.label()),
            H::LodDistance => match g.lod_distance {
                0 => labelled("LOD Distance", "Off"),
                n => labelled("LOD Distance", lang::tr("%s chunks", &[&n])),
@@ -887,6 +893,7 @@ impl H {
            H::ParticleCulling => labelled("Particle Culling", g.particle_culling.label()),
            H::LeafCulling => labelled("Leaf Culling", g.leaf_culling.label()),
            H::OpaqueIce => labelled("Opaque Ice", on_off(g.opaque_ice)),
+            H::ParallelTick => labelled("Parallel Tick", g.parallel_tick.label()),
            H::CacheShulkerBoxes => labelled("Shulker Boxes", on_off(g.cache_shulker_boxes)),
            H::CacheSigns => labelled("Signs", on_off(g.cache_signs)),
            H::CacheDecoratedPots => labelled("Decorated Pots", on_off(g.cache_decorated_pots)),
@@ -1041,6 +1048,9 @@ impl H {
                g.leaf_culling = step(&LeafCullingMode::ALL, g.leaf_culling, back);
            }
            H::OpaqueIce => g.opaque_ice = !g.opaque_ice,
+            H::ParallelTick => {
+                g.parallel_tick = step(&ParallelTickMode::ALL, g.parallel_tick, back)
+            }
            H::CacheShulkerBoxes => g.cache_shulker_boxes = !g.cache_shulker_boxes,
            H::CacheSigns => g.cache_signs = !g.cache_signs,
            H::CacheDecoratedPots => g.cache_decorated_pots = !g.cache_decorated_pots,
@@ -1290,13 +1300,13 @@ impl Item {
                        | H::Pacing
                        | H::PresentMode
                        | H::Workers
+                        | H::ParallelTick
                        | H::FrameGeneration
                        | H::BatteryMode
                        | H::ShadowCache
                        | H::GraphicsApi
                        | H::TranslucentBatching
                        | H::HdrSmoothGradients
-                        | H::GpuCulling
                )
                | Item::Vanilla(
                    Opt::GuiScale
@@ -1753,6 +1763,14 @@ mod tests {
        ui.set_search("tearing");
        let found = ui.listed(&s, SIZE);
        assert!(found.iter().any(|(_, i)| *i == Item::Vanilla(Opt::Vsync)));
+        // Both presets answer "preset"; Horizon's own, named apart from vanilla's, answers its name.
+        ui.set_search("preset");
+        let found = ui.listed(&s, SIZE);
+        let general = |item| (Page::General, item);
+        assert!(found.contains(&general(Item::Horizon(H::Preset))));
+        assert!(found.contains(&general(Item::Vanilla(Opt::Preset))));
+        ui.set_search("horizon preset");
+        assert_eq!(ui.listed(&s, SIZE), [general(Item::Horizon(H::Preset))]);
        ui.set_search("hdr");
        let [x, y, w, h] = cols.page(Page::ALL.len() - 1);
        press(&mut ui, &mut s, (x + w / 2.0, y + h / 2.0));
@@ -2225,9 +2243,18 @@ mod tests {
    fn presets_set_vanilla_and_horizon_options() {
        let mut s = Settings::default();
        Item::Horizon(H::Preset).cycle(&mut s, false, [854, 480], &NONE);
+        assert_eq!(s.horizon.preset, Preset::FullPerformance);
+        assert_eq!(s.render_distance, 6);
+        assert_eq!(s.clouds, "false");
+        assert_eq!(s.horizon.resolution_scale, 75);
+        assert_eq!(s.horizon.entity_culling, EntityCullingMode::Asynchronous);
+        assert!(s.horizon.opaque_ice && s.horizon.cache_chests);
+        // The next one puts back what only Full Performance lowers.
+        Item::Horizon(H::Preset).cycle(&mut s, false, [854, 480], &NONE);
        assert_eq!(s.horizon.preset, Preset::Performance);
        assert_eq!(s.render_distance, 8);
-        assert_eq!(s.clouds, "false");
+        assert_eq!(s.horizon.resolution_scale, 100);
+        assert!(!s.horizon.opaque_ice && s.horizon.cache_chests);
        // Any quality change leaves the preset.
        Item::Vanilla(Opt::Clouds).cycle(&mut s, false, [854, 480], &NONE);
        assert_eq!(s.horizon.preset, Preset::Custom);
@@ -2235,6 +2262,14 @@ mod tests {
        Item::Horizon(H::Preset).cycle(&mut s, true, [854, 480], &NONE);
        Item::Vanilla(Opt::Vsync).cycle(&mut s, false, [854, 480], &NONE);
        assert_eq!(s.horizon.preset, Preset::Ultra);
+        // Ultra keeps the optimizations that leave the picture as it is, and no others.
+        assert_eq!(s.horizon.entity_culling, EntityCullingMode::Asynchronous);
+        assert_eq!(s.horizon.gpu_culling, GpuCullingMode::Auto);
+        assert_eq!((s.horizon.lod_distance, s.horizon.fxaa), (128, true));
+        assert_eq!(
+            (s.horizon.resolution_scale, s.horizon.opaque_ice),
+            (100, false)
+        );
    }

    #[test]
@@ -2249,7 +2284,7 @@ mod tests {
        assert_eq!(seen, [2, 4, 8, 1]);
        Item::Horizon(H::ScreenshotQuality).cycle(&mut s, true, [854, 480], &NONE);
        assert_eq!(s.horizon.screenshot_quality, 8);
-        assert_eq!(s.horizon.preset, Preset::Performance);
+        assert_eq!(s.horizon.preset, Preset::FullPerformance);
    }

    #[test]
@@ -2297,14 +2332,6 @@ mod tests {
        let item = Item::Horizon(H::EntityCulling);
        assert_eq!(s.horizon.entity_culling, EntityCullingMode::Off);
        assert_eq!(item.label(&s, &NONE).plain(), "Entity Culling: Off");
-        for mode in EntityCullingMode::ALL {
-            s.horizon.entity_culling = mode;
-            for preset in Preset::ALL {
-                crate::graphics::apply_preset(preset, &mut s);
-                assert_eq!(s.horizon.entity_culling, mode);
-            }
-        }
-        s.horizon.entity_culling = EntityCullingMode::Off;
        let mut ui = ui();
        let r = row(&mut ui, &s, item);
        for mode in [
@@ -2333,10 +2360,6 @@ mod tests {
        assert_eq!(item.label(&s, &NONE).plain(), "Particle Culling: Off");
        for mode in ParticleCullingMode::ALL {
            s.horizon.particle_culling = mode;
-            for preset in Preset::ALL {
-                crate::graphics::apply_preset(preset, &mut s);
-                assert_eq!(s.horizon.particle_culling, mode);
-            }
            assert_eq!(
                crate::graphics::Graphics::parse(&s.horizon.serialize()).particle_culling,
                mode
@@ -2530,8 +2553,8 @@ mod tests {
        }
    }

-    /// GPU Culling: Off, On or Auto right after Cave Culling, off by default, no part of a
-    /// preset, and greyed out with its reason, reading Off, wherever it isn't offered.
+    /// GPU Culling: Off, On or Auto right after Cave Culling, off by default, and greyed out
+    /// with its reason, reading Off, wherever it isn't offered.
    #[test]
    fn gpu_culling_steps_off_on_auto_where_it_is_offered() {
        use crate::graphics::GpuCullingOffer;
@@ -2570,7 +2593,7 @@ mod tests {
            assert!(key(&mut ui, &mut s, K::Enter).is_empty());
            assert_eq!(s.horizon.gpu_culling, GpuCullingMode::On, "{offer:?}");
        }
-        // Where it is, it steps through its three values and keeps the preset.
+        // Where it is, it steps through its three values and leaves the preset.
        crate::graphics::offer_gpu_culling(GpuCullingOffer::Offered);
        assert_eq!(item.blocked(&s, &NONE), None);
        for label in ["Auto", "Off", "On"] {
@@ -2586,18 +2609,10 @@ mod tests {
        }
        item.cycle(&mut s, true, FB, &NONE);
        assert_eq!(s.horizon.gpu_culling, GpuCullingMode::Off);
-        assert_eq!(s.horizon.preset, Preset::Balanced);
+        assert_eq!(s.horizon.preset, Preset::Custom);
        // Auto says what it does.
        s.horizon.gpu_culling = GpuCullingMode::Auto;
        assert!(description(item, &s, &NONE, "").starts_with("Auto: "));
-        // No preset sets it.
-        for mode in GpuCullingMode::ALL {
-            s.horizon.gpu_culling = mode;
-            for preset in Preset::ALL {
-                crate::graphics::apply_preset(preset, &mut s);
-                assert_eq!(s.horizon.gpu_culling, mode, "{preset:?}");
-            }
-        }
    }

    #[test]
@@ -20,15 +20,20 @@ struct Params {
    black: f32,
    // The HUD and menus' brightness as a share of paper white.
    ui: f32,
-    // HDR lighting: what the strongest light multiplies a surface by, 1 for none.
+    // The compatibility frame's lift (`lit`; the float frame's writers have theirs from
+    // Hdr::draw_params). HDR lighting: what the strongest light multiplies a surface by, 1 for
+    // none.
    scene: f32,
-    // Per tier, low to very bright (hdr.rs `Tier`): the share of the headroom
+    // Per tier, low to very bright (hdr.rs `COMPAT_SHARES`): the share of the headroom
    // its fully lifted pixels get.
    share: vec4<f32>,
    // HDR calibration (hdr_calibration.rs): x its step (0 none, 1 black level,
    // 2 peak, 3 paper white), y the slider in nits, z where its controls start,
    // a share of the height.
    calibration: vec4<f32>,
+    // The scene's peak in units of paper white where Horizon lifts the world (hdr.rs
+    // `SCENE_PEAK`), else 0: what the tone curve maps onto the display's peak (`tone_scale`).
+    scene_peak: f32,
 };
@group(0) @binding(2) var<uniform> params: Params;
 // Horizon's logo, 1 inside, 0 outside, for calibration's test pictures.
@@ -155,7 +160,7 @@ fn calibration_nits(p: vec2<f32>, size: vec2<f32>) -> f32 {
 }

 fn lit(f: vec3<f32>, a: f32, shows: bool, eased: bool) -> Lit {
-    return hdr_mark_light(f, a, shows, eased, vec4(params.peak, params.scene, params.world, params.debug), params.share);
+    return hdr_mark_light(f, a, shows, eased, vec4(params.peak, params.scene, params.world, params.debug), (params.peak - 1.0) * params.share);
 }

 // Calibration: above its controls the test picture, straight in nits, past
@@ -251,33 +256,52 @@ fn display(light: vec3<f32>, pos: vec4<f32>) -> vec4<f32> {
    return display(light, pos);
 }

-// The tone curve's knee: up to it light stays as it is. Where HDR lighting eased into the peak
-// before the curve (`lit`), 60% of it, so bright textures keep their detail; at least paper white.
+// Where the scene's peak is unknown (`tone_scale`), the curve's knee: up to it light stays as it
+// is. Where HDR lighting eased into the peak before the curve (`lit`), 60% of it, so bright
+// textures keep their detail; at least paper white.
 fn tone_knee(headroom: f32) -> f32 {
    return max(0.6 * headroom, 1.0);
 }

-// The tone curve on light whose brightest channel is `top`, in units of paper white `paper`
-// nits: what to scale the light by, so it ends at most `headroom` (above 1). ITU-R BT.2390's
-// EETF in PQ, without the black level lift (`display` does that): the same up to its knee, then
-// a Hermite spline that reaches the peak level, at the source's peak. That peak is where the knee
-// lands at `tone_knee`, PQ's 10 000 nits at most; light past it shows at the peak. The brightest
-// channel sets the scale for all three, so light keeps its hue as it eases (lava stays orange)
-// and no channel passes the peak.
-fn tone_scale(top: f32, headroom: f32, paper: f32) -> f32 {
-    if top <= tone_knee(headroom) {
-        return 1.0;
-    }
+// The tone curve on light whose brightest channel is `top`, in units of paper white `paper` nits:
+// what to scale the light by, so it ends at most `headroom` (T). ITU-R BT.2390's EETF in PQ,
+// without the black level lift (`display` does that): the same up to its knee, then a Hermite
+// spline reaching T at the source's peak, past which light shows at T. The brightest channel sets
+// the scale for all three, so light keeps its hue (lava stays orange) and no channel passes T.
+//
+// The source is the scene's peak S where Horizon lifts the world (`scene_peak`, hdr.rs
+// `SCENE_PEAK`): the world's light is the same on every display, light past S is held at S, and
+// where T reaches S that is all, so a display above S shows the world as one at S. Where the
+// scene's range is unknown (`scene_peak` 0: a 0.2 pack's own light, HDR Lighting off), the
+// source follows the display, as the 0.2 contract has it: the peak that puts the EETF's knee at
+// `tone_knee`, PQ's 10 000 nits at most.
+fn tone_scale(top: f32, scene_peak: f32, headroom: f32, paper: f32) -> f32 {
    let peak = pq(vec3(headroom * paper)).x;
-    let source = min(3.0 * peak - 2.0 * pq(vec3(tone_knee(headroom) * paper)).x, 1.0);
-    let e = pq(vec3(top * paper)).x / source;
+    var source: f32;
+    var e: f32;
+    var held = 1.0;
+    if scene_peak > 0.0 {
+        held = min(1.0, scene_peak / max(top, 1e-6));
+        if scene_peak <= headroom {
+            return held;
+        }
+        source = pq(vec3(scene_peak * paper)).x;
+        e = pq(vec3(min(top, scene_peak) * paper)).x / source;
+    } else {
+        if top <= tone_knee(headroom) {
+            return 1.0;
+        }
+        source = min(3.0 * peak - 2.0 * pq(vec3(tone_knee(headroom) * paper)).x, 1.0);
+        e = pq(vec3(top * paper)).x / source;
+    }
    let max_lum = peak / source;
-    let ks = 1.5 * max_lum - 0.5;
+    // At least 0: past 3 to 1 in PQ the knee would leave the source's range.
+    let ks = max(1.5 * max_lum - 0.5, 0.0);
    if e >= 1.0 {
        return headroom / top;
    }
    if e <= ks {
-        return 1.0;
+        return held;
    }
    let t = (e - ks) / (1.0 - ks);
    let t2 = t * t;
@@ -287,16 +311,16 @@ fn tone_scale(top: f32, headroom: f32, paper: f32) -> f32 {
 }

 // Hdr::tonemap, after the post effects and before the camera overlays (docs/design/
-// hdr-linear-light.md, `[tonemap]`): the light (`world` holds the frame) eased into the peak, in
-// gamma, where scaling the light by s scales the stored colour by s^(1/2.2). Light up to the
-// knee stays exactly as stored. With no headroom, a clip at white.
+// hdr-linear-light.md, `[tonemap]`): the light (`world` holds the frame) fitted to the display, in
+// gamma, where scaling the light by s scales the stored colour by s^(1/2.2). Light the curve
+// leaves alone stays exactly as stored. With no headroom and no scene peak, a clip at white.
@fragment fn fs_tonemap(@builtin(position) pos: vec4<f32>) -> @location(0) vec4<f32> {
    let g = textureLoad(world, vec2<i32>(pos.xy), 0).rgb;
-    if params.peak <= 1.0 {
+    if params.scene_peak == 0.0 && params.peak <= 1.0 {
        return vec4(min(g, vec3(1.0)), 1.0);
    }
    let top = pow(max(max(g.r, max(g.g, g.b)), 0.0), 2.2);
-    let s = tone_scale(top, params.peak, params.paper * 80.0);
+    let s = tone_scale(top, params.scene_peak, params.peak, params.paper * 80.0);
    return vec4(select(g * pow(s, 1.0 / 2.2), g, s == 1.0), 1.0);
 }

@@ -331,7 +355,7 @@ fn layered(at: vec2<i32>) -> vec3<f32> {
 }

 // Screenshots keep midtones at their drawn brightness, with a shoulder starting at 0.6
-// paper white in linear light. Unlike the display curve (whose knee is at least white),
+// paper white in linear light. Unlike the display curve (which ends at the display's peak),
 // this has an unbounded source range: k + (1-k)*(top-k)/(top+1-2*k) approaches SDR
 // white smoothly, with slope 1 at k. One scale keeps the world's linear RGB ratios.
 fn screenshot_world(w: vec3<f32>) -> vec3<f32> {
@@ -27,7 +27,8 @@ struct Lit {
    lifted: bool,
 };

-fn hdr_mark_light(f: vec3<f32>, a: f32, shows: bool, eased: bool, settings: vec4<f32>, shares: vec4<f32>) -> Lit {
+// `lifts`, per tier: how much its fully lifted pixels gain over their own light (their gain - 1).
+fn hdr_mark_light(f: vec3<f32>, a: f32, shows: bool, eased: bool, settings: vec4<f32>, lifts: vec4<f32>) -> Lit {
    var lifted = false;
    // Light over 1 (a float frame's) shows only where the world does and carries
    // no mark (alpha 1), up to the peak: light written as light. Marked pixels clip
@@ -60,7 +61,7 @@ fn hdr_mark_light(f: vec3<f32>, a: f32, shows: bool, eased: bool, settings: vec4
        let lift = 1.0 - clamp((a - 0.175 * f32(band)) / 0.165, 0.0, 1.0);
        if lift > 0.0 {
            let top = max(light.r, max(light.g, light.b));
-            var gain = 1.0 + (settings.x - 1.0) * shares[tier] * lift;
+            var gain = 1.0 + lifts[tier] * lift;
            if eased {
                gain = min(gain, settings.x / max(top, 1e-4));
            }
@@ -88,7 +89,8 @@ fn hdr_quantized_mark(mark: f32) -> f32 {
    return round(saturate(mark) * 255.0) / 255.0;
 }

-fn hdr_written(color: vec3<f32>, mark: f32, settings: vec4<f32>, shares: vec4<f32>) -> vec3<f32> {
-    let shows = settings.z > 0.5 && settings.x > 1.0;
-    return pow(hdr_mark_light(max(color, vec3(0.0)), hdr_quantized_mark(mark), shows, false, settings, shares).light, vec3(1.0 / 2.2));
+// The world's writers' light, from the tiers' `gains` (Hdr::draw_params): the same on every
+// display; the tone curve fits it to the display afterwards (fs_tonemap).
+fn hdr_written(color: vec3<f32>, mark: f32, settings: vec4<f32>, gains: vec4<f32>) -> vec3<f32> {
+    return pow(hdr_mark_light(max(color, vec3(0.0)), hdr_quantized_mark(mark), settings.z > 0.5, false, settings, gains - vec4(1.0)).light, vec3(1.0 / 2.2));
 }
@@ -16,6 +16,7 @@ use model_reducing::reducible_model_sprites;

 mod animate;
 pub mod cit_glint;
+mod gui_sprite;
 mod model_reducing;
 mod pack_text;
 pub mod pictures;
@@ -55,7 +56,7 @@ pub struct TextureFlags {
 impl TextureFlags {
    /// The `texture` section of a `.png.mcmeta` file, if it sets either flag.
    pub fn from_mcmeta(json: &str) -> Option<Self> {
-        let meta = crate::packs::first_json(json.as_bytes())?;
+        let meta: serde_json::Value = crate::packs::first_json(json.as_bytes()).ok()?;
        let section = meta.get("texture")?;
        let flag = |key| section.get(key).and_then(serde_json::Value::as_bool) == Some(true);
        let flags = Self {
@@ -388,7 +389,7 @@ fn strip_frame(pixels: &[u8], stride: u32, x: u32, y: u32, w: u32, h: u32) -> Ve
 }
 /// The `animation` section of a texture's `.mcmeta`.
 fn animation_of(mcmeta: Option<&str>) -> Option<AnimationMetadata> {
-    let meta = crate::packs::first_json(mcmeta?.as_bytes())?;
+    let meta: serde_json::Value = crate::packs::first_json(mcmeta?.as_bytes()).ok()?;
    AnimationMetadata::from_json(&meta.get("animation")?.to_string()).ok()
 }
 /// An animated strip's first frame: the region the mcmeta's frame size picks
@@ -1401,9 +1402,9 @@ impl HudAtlas {
            edition.3 = pixels;
        }
        images.push(("horizon/white".into(), 4, 4, vec![255; 64]));
-        // The controller's art, unless a pack brought its own (walked above, as a mod's GUI
-        // textures are).
-        for image in crate::pad_glyph::images() {
+        // The controller's art and Horizon's mark, unless a pack brought its own (walked above, as a
+        // mod's GUI textures are).
+        for image in crate::pad_glyph::images().chain(crate::mark_sprite::image()) {
            if !images.iter().any(|i| i.0 == image.0) {
                images.push(image);
            }
@@ -2466,9 +2467,8 @@ impl HudBatch {
                    );
                }
            }
-            InlineObject::Atlas { sprite, .. } => {
-                let key = sprite.strip_prefix("minecraft:").unwrap_or(sprite);
-                if let Some(rect) = atlas.sprites.get(key).copied() {
+            InlineObject::Atlas { .. } => {
+                if let Some(rect) = atlas.inline_object_sprite(object) {
                    self.rect_uv(x, y, 8.0, 8.0, rect, tint);
                }
            }
@@ -3773,6 +3773,32 @@ mod tests {
        assert_eq!(banner.texels((atlas.width, atlas.height)), (16, 32));
    }
    #[test]
+    fn an_inline_atlas_sprite_resolves_in_its_named_atlas() {
+        let root =
+            std::env::temp_dir().join(format!("horizon-atlas-inline-{}", std::process::id()));
+        let gui = root.join("assets/minecraft/textures/gui/sprites/boss_bar");
+        fs::create_dir_all(&gui).unwrap();
+        write_strip(
+            &gui.join("pink_background.png"),
+            16,
+            16,
+            &[[1, 2, 3, 255]],
+            None,
+        );
+        let atlas = HudAtlas::build(&root).unwrap();
+        let _ = fs::remove_dir_all(&root);
+        let packed = atlas.sprites["gui/sprites/boss_bar/pink_background"];
+        let missing = atlas.sprites[MISSING_SPRITE];
+        let found = atlas
+            .inline_sprite("minecraft:gui", "minecraft:boss_bar/pink_background")
+            .unwrap();
+        assert_eq!((found.u0, found.v0), (packed.u0, packed.v0));
+        let none = atlas
+            .inline_sprite("minecraft:gui", "minecraft:boss_bar/nope")
+            .unwrap();
+        assert_eq!((none.u0, none.v0), (missing.u0, missing.v0));
+    }
+    #[test]
    fn a_root_single_sprite_strip_taller_than_the_atlas_packs_one_frame() {
        let root = animated_root();
        let atlases = root.join("assets/minecraft/atlases");
@@ -0,0 +1,41 @@
+use super::{HudAtlas, MISSING_SPRITE, Rect};
+
+/// The packed key of a GUI sprite id: `minecraft:boss_bar/pink_background` is
+/// `gui/sprites/boss_bar/pink_background`, another namespace's `ns:gui/sprites/...`.
+fn atlas_key_of_gui_sprite(id: &str) -> String {
+    match id.split_once(':') {
+        Some(("minecraft", path)) => format!("gui/sprites/{path}"),
+        Some((namespace, path)) => format!("{namespace}:gui/sprites/{path}"),
+        None => format!("gui/sprites/{id}"),
+    }
+}
+
+impl HudAtlas {
+    /// `AtlasGlyphProvider`: the sprite `sprite` of the atlas named `atlas`
+    /// (`minecraft:gui` keeps its sprites under `gui/sprites/`), or the missing
+    /// sprite when that atlas has none by that name.
+    pub fn inline_sprite(&self, atlas: &str, sprite: &str) -> Option<Rect> {
+        let plain = sprite.strip_prefix("minecraft:").unwrap_or(sprite);
+        let gui = atlas_key_of_gui_sprite(sprite);
+        let gui_atlas = atlas.strip_prefix("minecraft:").unwrap_or(atlas) == "gui";
+        let (first, second) = if gui_atlas {
+            (gui.as_str(), plain)
+        } else {
+            (plain, gui.as_str())
+        };
+        self.sprites
+            .get(first)
+            .or_else(|| self.sprites.get(second))
+            .or_else(|| self.sprites.get(MISSING_SPRITE))
+            .copied()
+    }
+    /// `inline_sprite` for an inline atlas object; `None` for any other object.
+    pub(super) fn inline_object_sprite(&self, object: &crate::text::InlineObject) -> Option<Rect> {
+        match object {
+            crate::text::InlineObject::Atlas { atlas, sprite, .. } => {
+                self.inline_sprite(atlas, sprite)
+            }
+            _ => None,
+        }
+    }
+}
@@ -39,14 +39,13 @@ pub fn text_with_backdrop(
    background: u32,
 ) {
    if background != 0 {
-        // Font.PreparedTextBuilder.markBackground: one pixel above and left of
-        // the glyphs, the glyph advance to the right and nine high: not a
-        // fixed two-pixel frame.
+        // GuiGraphicsExtractor.textWithBackdrop adds two pixels around the
+        // text's advance and the font's nine-pixel line height.
        out.push(fill(
-            x - 1,
-            y - 1,
-            x + w,
-            y + 9,
+            x - 2,
+            y - 2,
+            x + w + 2,
+            y + 11,
            multiply(background, color),
        ));
    }
@@ -1491,10 +1490,10 @@ mod boss_bar_room_tests {
 mod backdrop_tests {
    use super::*;

-    /// `markBackground`: the backdrop reaches one pixel above and left of the
-    /// glyphs, their advance to the right and nine down, not 2 on every side.
+    /// `GuiGraphicsExtractor.textWithBackdrop`: two pixels around the advance
+    /// and the nine-pixel font line, independently of glyph-background drawing.
    #[test]
-    fn the_backdrop_frames_the_glyphs_by_one_pixel() {
+    fn the_backdrop_frames_the_text_by_two_pixels() {
        let mut out = Vec::new();
        text_with_backdrop(
            &mut out,
@@ -1508,6 +1507,6 @@ mod backdrop_tests {
        let Some(GuiDraw::Fill { x0, y0, x1, y1, .. }) = out.first() else {
            panic!("a backdrop is a fill first");
        };
-        assert_eq!((*x0, *y0, *x1, *y1), (9, 19, 16, 29));
+        assert_eq!((*x0, *y0, *x1, *y1), (8, 18, 18, 31));
    }
 }
@@ -74,6 +74,7 @@ pub mod level_loading;
 pub mod light;
 pub mod lod;
 pub mod logging;
+pub mod mark_sprite;
 pub mod menu_blur;
 pub mod menu_style;
 pub mod mesher;
@@ -102,6 +103,9 @@ pub mod pad_glyph;
 pub mod paged_maps;
 pub mod par;
 pub mod particles;
+#[cfg(target_os = "linux")]
+pub mod perf_capture;
+pub mod perf_gpu;
 pub mod poi_sections;
 pub mod polytone_post;
 pub mod post_chain;
@@ -9,6 +9,7 @@ use crate::{
 };
 pub mod bake;
 pub mod cache;
+mod detail;
 mod kept;
 mod mesh;
 pub mod packed;
@@ -2387,13 +2388,6 @@ impl Lod {
            self.shared.mesh_wake.notify_all();
        }
    }
-    /// Reduced far detail (`graphics::FarDetail::Reduced`): the next update
-    /// replans when it changes, and tiles sampled from then on approximate
-    /// wide cells (`GeneratorWorker::lod_grid`).
-    pub fn set_reduced_detail(&mut self, reduced: bool) {
-        self.reduced_detail = reduced;
-        self.shared.approximate.store(reduced, Ordering::Relaxed);
-    }
    fn held(&self) -> bool {
        self.small && self.near_loading
    }
@@ -6115,4 +6109,34 @@ mod tests {
        assert!(lod.stale.contains(&key));
        assert_eq!(queued(&mut lod), [key]);
    }
+
+    #[test]
+    fn changing_far_detail_samples_tiles_again() {
+        for level in [0, 1, 2, 3, 5] {
+            let mut lod = Lod::scheduler_for_test();
+            let key = TileKey { x: 0, z: 0, level };
+            lod.plan.nodes.insert(key);
+            lod.active.insert(key);
+            lod.ready.insert(key, Arc::new(samples(70)));
+            assert!(
+                queued(&mut lod).is_empty(),
+                "level {level}: sampled tile is not asked again"
+            );
+            lod.set_reduced_detail(true);
+            assert!(
+                lod.ready.contains_key(&key),
+                "level {level}: old samples stay"
+            );
+            assert_eq!(queued(&mut lod), [key], "level {level}: not sampled again");
+            lod.finish_sample(key, samples(70));
+            lod.set_reduced_detail(true);
+            assert!(queued(&mut lod).is_empty(), "level {level}: same value");
+            lod.set_reduced_detail(false);
+            assert_eq!(
+                queued(&mut lod),
+                [key],
+                "level {level}: not sampled again on the way back"
+            );
+        }
+    }
 }
@@ -0,0 +1,23 @@
+//! Reduced far detail.
+use super::*;
+
+impl Lod {
+    /// Reduced far detail (`graphics::FarDetail::Reduced`): the next update
+    /// replans when it changes, and tiles sampled from then on approximate
+    /// wide cells (`GeneratorWorker::lod_grid`).
+    pub fn set_reduced_detail(&mut self, reduced: bool) {
+        if self.reduced_detail != reduced {
+            let keys: Vec<_> = self
+                .ready
+                .keys()
+                .chain(self.pending.iter())
+                .copied()
+                .collect();
+            for key in keys {
+                self.mark_stale(key);
+            }
+        }
+        self.reduced_detail = reduced;
+        self.shared.approximate.store(reduced, Ordering::Relaxed);
+    }
+}
@@ -0,0 +1,11 @@
+//! Horizon's mark (`docs/media/brand/mark-dark.svg`) on the text grid, for an inline text sprite.
+
+/// The mark's name in the HUD atlas.
+pub const SPRITE: &str = "horizon:gui/mark";
+const PNG: &[u8] = include_bytes!("../../horizon-client/assets/horizon/textures/gui/mark.png");
+
+/// The mark as the HUD atlas takes an image.
+pub fn image() -> std::iter::Once<(String, u32, u32, Vec<u8>)> {
+    let (width, height, rgba) = crate::hud::decode_bytes(PNG).expect("Horizon's mark is PNG");
+    std::iter::once((SPRITE.to_owned(), width, height, rgba))
+}
@@ -24,7 +24,7 @@ fn oit_cloud_color(in: Out, front: bool, fade: bool) -> vec4<f32> {
    var color = oit_cloud_color(in, front, true);
    if HDR_WRITE_LIGHT && globals.hdr_light.w != 0.0 {
        color = vec4(hdr_written(color.rgb, hdr_scene_alpha(globals.hdr_light.y),
-            globals.hdr_settings, globals.hdr_shares), color.a);
+            globals.hdr_settings, globals.hdr_gains), color.a);
    }
    let seen = oit_sample_transmittance(vec2<i32>(in.clip.xy),
        oit_normalize_depth(in.clip.z, in.clip.xy), 1.0 - color.a);
@@ -62,7 +62,7 @@
@fragment fn fs_oit_lightning_accumulate(in: Out) -> @location(0) vec4<f32> {
    var color = celestial_color(in);
    if HDR_WRITE_LIGHT && globals.hdr_light.w != 0.0 {
-        color = vec4(hdr_written(color.rgb, hdr_entity_mark(in), globals.hdr_settings, globals.hdr_shares), color.a);
+        color = vec4(hdr_written(color.rgb, hdr_entity_mark(in), globals.hdr_settings, globals.hdr_gains), color.a);
    }
    return oit_accumulate_additive(vec4(color.rgb, min(0.99, color.a)), 0.0, in.clip);
 }
@@ -41,7 +41,7 @@ fn oit_terrain_color(in: TerrainOut) -> vec4<f32> {
            globals.hdr_light.y, f * globals.fog_color.a));
        // Convert the surface before weighting; its mark never belongs to the light behind it.
        let fogged = mix(color.rgb, globals.fog_color.rgb, f * globals.fog_color.a);
-        return vec4(hdr_written(fogged, mark, globals.hdr_settings, globals.hdr_shares) * weighted.a, weighted.a);
+        return vec4(hdr_written(fogged, mark, globals.hdr_settings, globals.hdr_gains) * weighted.a, weighted.a);
    }
    return vec4(rgb, weighted.a);
 }
@@ -1594,9 +1594,9 @@ pub struct OptionsUi {
    radial_pick: shell::Shell<crate::radial_editor::PickScreen>,
    /// Shaders: the shader packs and the picked one's options, on the settings shell.
    shader: shell::Shell<crate::shader_ui::ShaderScreen>,
-    /// The Pack Options page, and the packs' Polytone config entries by pack id (the game
-    /// fills them beside `pack_infos`).
-    pub pack_options: crate::pack_options_ui::PackOptionsUi,
+    /// Pack Options, on the settings shell, and the packs' Polytone config entries by pack id
+    /// (the game fills them beside `pack_infos`).
+    pack_options: shell::Shell<crate::pack_options_ui::PackOptionsScreen>,
    pub pack_configs: std::collections::BTreeMap<String, horizon_polytone::pack::Configs>,
    pub split_profiles: crate::split_profiles::SplitProfiles,
    /// HDR calibration while its page is open.
@@ -3401,10 +3401,6 @@ impl OptionsUi {
            c.draw(batch, atlas, cursor);
            return;
        }
-        if self.page() == Page::PackOptions {
-            self.pack_options.draw(batch, atlas, cursor, self.in_world);
-            return;
-        }
        let waiting = self.waiting();
        let in_world = self.in_world;
        if self.draw_radial_name(batch, atlas, cursor, in_world) {
@@ -3786,20 +3782,6 @@ impl OptionsUi {
            });
            return self.shell_events(s, outputs);
        }
-        if self.page() == Page::PackOptions {
-            let mut events = Vec::new();
-            for action in self
-                .pack_options
-                .click((x, y), size, drag, right || self.shift)
-            {
-                match action {
-                    crate::pack_options_ui::Action::ButtonClick => events.push(Event::ButtonClick),
-                    crate::pack_options_ui::Action::SliderDrag => {}
-                    crate::pack_options_ui::Action::Done => events.extend(self.back(s)),
-                }
-            }
-            return events;
-        }
        if self.page() == Page::Packs {
            let mut events = Vec::new();
            if drag {
@@ -3829,14 +3811,7 @@ impl OptionsUi {
                crate::pack_screen::Action::BrowsePick(i) => {
                    events.push(Event::DownloadPack(i));
                }
-                crate::pack_screen::Action::Options(id) => {
-                    let mut configs = horizon_polytone::pack::Configs::default();
-                    if let Some(own) = self.pack_configs.get(&id) {
-                        configs.merge(own);
-                    }
-                    self.pack_options = crate::pack_options_ui::PackOptionsUi::open(configs);
-                    self.push(Page::PackOptions);
-                }
+                crate::pack_screen::Action::Options(id) => self.open_pack_options(&id),
                crate::pack_screen::Action::None => {}
            }
            return events;
@@ -4074,7 +4049,6 @@ impl OptionsUi {
        // release, even if the pointer has left the widget or its value stayed.
        let slider = self.dragging.take().is_some();
        let shell_slider = self.shell_mut().and_then(|shell| shell.release());
-        self.pack_options.release();
        let calibration_slider = self.calibration.as_mut().is_some_and(|c| c.release());
        let split_drop = self.split_setup.release();
        if slider || shell_slider.is_some() || calibration_slider {
@@ -4168,10 +4142,6 @@ impl OptionsUi {
            self.studio.wheel(amount);
            return Vec::new();
        }
-        if self.page() == Page::PackOptions {
-            self.pack_options.scroll(size, amount);
-            return Vec::new();
-        }
        let plain = self.resource_error.is_none()
            && !(self.pack_screen.is_some() && self.stack.last() == Some(&Page::Packs));
        if !plain {
@@ -4255,10 +4225,6 @@ impl OptionsUi {
            self.studio.wheel(amount);
            return;
        }
-        if self.page() == Page::PackOptions {
-            self.pack_options.scroll(size, amount);
-            return;
-        }
        match &mut self.pack_screen {
            Some(p) if self.stack.last() == Some(&Page::Packs) => {
                p.scroll(cursor.0 as f64, cursor.1 as f64, amount as f64)
@@ -4393,14 +4359,8 @@ impl OptionsUi {
        self.can_change_value = false;
        match page {
            Page::PackOptions => {
-                let ui = std::mem::take(&mut self.pack_options);
-                if ui.changed {
-                    let entries = ui.configs.entries().keys().cloned().collect();
-                    events.push(Event::PackOptions {
-                        entries,
-                        chosen: ui.configs.chosen(),
-                    });
-                }
+                let screen = std::mem::take(&mut self.pack_options.screen);
+                events.extend(screen.finished());
            }
            Page::ShaderOptions | Page::ShaderPacks => {
                if s.shader_options.as_ref().is_some_and(|o| o.changed) {
@@ -4960,6 +4920,34 @@ mod tests {
    /// A renderer whose destination offers nothing and whose display reports nothing.
    const NONE: EffectiveOutput = EffectiveOutput::NONE;

+    #[test]
+    fn pack_options_leave_with_a_change_and_with_nothing_after_its_undo() {
+        use crate::settings_shell::Screen as _;
+        let mut s = Settings::default();
+        let atlas = HudAtlas::build(std::path::Path::new("/nonexistent/horizon-test-assets"));
+        let atlas = atlas.unwrap();
+        let mut ui = OptionsUi::default();
+        let mut configs = horizon_polytone::pack::Configs::default();
+        let birds = serde_json::json!({"default_value": true});
+        configs.add_entry("p:birds".into(), &birds);
+        ui.pack_configs.insert("pack".into(), configs);
+        for undone in [false, true] {
+            ui.open_pack_options("pack");
+            assert!(ui.shell().is_some(), "Pack Options is on the shell");
+            let birds = crate::pack_options_ui::Item::Entry(0);
+            ui.pack_options.screen.press(&mut s, birds, false);
+            if undone {
+                let before = s.clone();
+                ui.pack_options.screen.undo(&mut s, &before);
+            }
+            let events = ui.key(&mut s, &atlas, winit::keyboard::KeyCode::Escape, None);
+            let sent = events
+                .iter()
+                .any(|e| matches!(e, Event::PackOptions { .. }));
+            assert_eq!(sent, !undone, "undone: {undone}");
+        }
+    }
+
    /// The window allows the input method only while `typing` says a search
    /// box has the focus (`Game::text_field_focused`), so a page without one
    /// must not claim the keys: the movement and menu keys keep working there.
@@ -23,6 +23,7 @@ impl OptionsUi {
            Page::ControllerRadialPick => Some(&self.radial_pick),
            page if Self::controller_page(page).is_some() => Some(&self.controller),
            page if Self::shader_page(page).is_some() => Some(&self.shader),
+            Page::PackOptions => Some(&self.pack_options),
            _ => None,
        }
    }
@@ -35,9 +36,20 @@ impl OptionsUi {
            Page::ControllerRadialPick => Some(&mut self.radial_pick),
            page if Self::controller_page(page).is_some() => Some(&mut self.controller),
            page if Self::shader_page(page).is_some() => Some(&mut self.shader),
+            Page::PackOptions => Some(&mut self.pack_options),
            _ => None,
        }
    }
+    /// Pack Options for the pack `id`, from the pack screen: its Polytone config entries.
+    pub(super) fn open_pack_options(&mut self, id: &str) {
+        let mut configs = horizon_polytone::pack::Configs::default();
+        if let Some(own) = self.pack_configs.get(id) {
+            configs.merge(own);
+        }
+        // Opening a shell starts it afresh: the entries go in after.
+        self.push(Page::PackOptions);
+        self.pack_options.screen = crate::pack_options_ui::PackOptionsScreen::open(configs);
+    }
    /// Where the open shell screen asked the focus to open (a radial slot's list, on the slot's
    /// action), for a controller's focus to land there.
    pub fn shell_opened_focus(&self) -> Option<[f32; 4]> {
@@ -53,13 +65,14 @@ impl OptionsUi {
            return;
        }
        // Every shell: the click may have changed the page.
-        let shells: [&mut dyn shell::Hosted; 6] = [
+        let shells: [&mut dyn shell::Hosted; 7] = [
            &mut self.extras,
            &mut self.graphics,
            &mut self.controller,
            &mut self.radial,
            &mut self.radial_pick,
            &mut self.shader,
+            &mut self.pack_options,
        ];
        for shell in shells {
            shell.clicks_step(false);
@@ -1,45 +1,36 @@
-//! The Pack Options page (#11486): the config entries of the selected resource packs' Polytone
-//! `config_entries` (wiki "Polytone Configs"), in the frame of Horizon's settings screens
-//! (`settings_shell`). Numbers are sliders, texts cycle, booleans switch; the entries sit in
-//! their `section`s, named by the packs' own translations. Leaving with Done keeps what changed,
-//! and the packs load again with it.
-use crate::widgets::Action as Declared;
+//! The Pack Options screen (#11486), on the settings shell (`settings_shell`): the config entries
+//! of the selected resource packs' Polytone `config_entries` (wiki "Polytone Configs"). Each
+//! `section` is a page, named by the packs' own translations; numbers are sliders that stop at
+//! the entry's `step`, value lists are choices, booleans switch and free text reads. The first
+//! page starts with the pack-wide presets and Reset all. The shell gives it the keyboard, a
+//! controller's focus, the search, the strip's descriptions and Undo; leaving keeps what differs
+//! from how the screen opened, and the packs load again with it.
 use crate::{
-    graphics_style as style,
-    hud::{HudAtlas, HudBatch},
    lang,
-    settings_shell::{self as shell, Columns, Line, Lines},
-    text::Text,
-    ui,
+    settings::Settings,
+    settings_shell::{self as shell, Group, Output, Row, Sheet, Value},
 };
 use horizon_polytone::pack::{ConfigKind, ConfigValue, Configs};

-/// What a click asks of the options screen.
+/// A row: the pack-wide presets, Reset all, or the entry at an index of `ids`.
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
-pub enum Action {
-    ButtonClick,
-    SliderDrag,
-    /// Done: leave, keeping what changed.
-    Done,
+pub(crate) enum Item {
+    Presets,
+    ResetAll,
+    Entry(u16),
 }

-/// The page's state: the entries being edited, how they are listed, and the pointer's hold.
-#[derive(Default)]
-pub struct PackOptionsUi {
-    /// The selected packs' entries and the values being picked.
-    pub configs: Configs,
-    /// Entry ids, by the row index the list uses.
-    ids: Vec<String>,
-    /// The sections in order: the `section` id (none for entries without one) and its rows.
-    sections: Vec<(Option<String>, Vec<u16>)>,
-    scroll: ui::Scroll,
-    dragging: Option<u16>,
-    /// A value changed since the page opened.
-    pub changed: bool,
-}
-
-/// The presets' row (and its section): past every entry's index.
-const PRESETS: u16 = u16::MAX;
+const TITLE: &str = "horizon.pack.options.title";
+/// The first page's group of rows for the whole pack, and every page's group of entries.
+const WHOLE_PACK: &str = "Whole pack";
+const PACK_OPTIONS: &str = "Pack settings";
+const RESET_ALL: &str = "Reset all";
+const RESET_ABOUT: &str = "Puts every option of this pack back to its default.";
+const AT_DEFAULTS: &str = "Every option is at its default already.";
+const PRESETS_ABOUT: &str = "Sets many options at once, as the pack groups them.";
+const PACK_SETTINGS: &str = "Settings made by the pack's author: they change only this pack.";
+/// A pack's tooltips, with the performance line after them, run longer than Horizon's own.
+const NOTE_LINES: usize = 3;

 /// A translation, or `fallback` where no language has the key.
 fn translated(key: &str, fallback: impl FnOnce() -> String) -> String {
@@ -65,9 +56,34 @@ fn readable(path: &str) -> String {
        .unwrap_or_default()
 }

-impl PackOptionsUi {
-    /// The page opens on `configs`, the selected packs' entries with the player's values.
-    pub fn open(configs: Configs) -> Self {
+/// A number as its entry shows it: whole with a whole step, else up to two decimals.
+fn number_text(n: f64, step: f64) -> String {
+    if step >= 1.0 && step.fract() == 0.0 {
+        format!("{n:.0}")
+    } else {
+        let text = format!("{n:.2}");
+        text.trim_end_matches('0').trim_end_matches('.').to_owned()
+    }
+}
+
+/// The screen: the entries being edited, as they were when it opened (for Undo and for whether
+/// leaving changes anything), and how they are paged.
+#[derive(Default)]
+pub(crate) struct PackOptionsScreen {
+    /// The selected packs' entries and the values being picked.
+    pub(crate) configs: Configs,
+    opened: Configs,
+    /// Entry ids, by `Item::Entry`'s index.
+    ids: Vec<String>,
+    /// The sections in order: the `section` id (none for entries without one) and its entries.
+    sections: Vec<(Option<String>, Vec<u16>)>,
+    /// Bumped on every change, for `stamp`: the values are floats, which don't hash.
+    revision: u64,
+}
+
+impl PackOptionsScreen {
+    /// The screen opens on `configs`, the selected packs' entries with the player's values.
+    pub(crate) fn open(configs: Configs) -> Self {
        let mut ids: Vec<(String, Option<String>, i64)> = configs
            .entries()
            .iter()
@@ -96,25 +112,21 @@ impl PackOptionsUi {
            (None, None) => a.0.cmp(&b.0),
        });
        Self {
+            opened: configs.clone(),
            configs,
            ids: ids.into_iter().map(|(id, ..)| id).collect(),
            sections: sections.into_iter().map(|(s, _, rows)| (s, rows)).collect(),
-            ..Self::default()
+            revision: 0,
        }
    }

-    fn layout(&self, w: f32, h: f32) -> (Columns, Vec<Line<u16, u16>>, f32) {
-        let cols = Columns::of(w, h);
-        let mut lines = Lines::new();
-        // The pack-wide presets first, when the entries have some.
-        if !self.configs.presets().is_empty() {
-            lines.titled(PRESETS, vec![PRESETS]);
-        }
-        for (i, (_, rows)) in self.sections.iter().enumerate() {
-            lines.titled(i as u16, rows.clone());
-        }
-        let (lines, content) = lines.finish();
-        (cols, lines, content)
+    /// What leaving sends: the entries and the player's choices, if they differ from how the
+    /// screen opened (an Undo, or a value stepped back, leaves nothing to send).
+    pub(crate) fn finished(&self) -> Option<crate::options_ui::Event> {
+        (self.configs != self.opened).then(|| crate::options_ui::Event::PackOptions {
+            entries: self.configs.entries().keys().cloned().collect(),
+            chosen: self.configs.chosen(),
+        })
    }

    /// The namespace the presets' translations are under: of the first entry with presets.
@@ -166,21 +178,14 @@ impl PackOptionsUi {
            None if back => n - 1,
            None => 0,
        };
-        let before = self.configs.clone();
        self.configs.apply_preset(&presets[next]);
-        if self.configs != before {
-            self.changed = true;
-        }
+        self.revision += 1;
    }

-    /// A section's heading: `config.<namespace>.section.<id>`, by its first entry's namespace.
-    fn section_name(&self, section: u16) -> String {
-        if section == PRESETS {
-            let key = format!("{}.presets", self.presets_namespace());
-            return translated(&key, || lang::get("horizon.pack.options.presets"));
-        }
-        let Some((id, rows)) = self.sections.get(usize::from(section)) else {
-            return String::new();
+    /// A section's page name: `config.<namespace>.section.<id>`, by its first entry's namespace.
+    fn section_name(&self, section: usize) -> String {
+        let Some((id, rows)) = self.sections.get(section) else {
+            return lang::get("horizon.pack.options.general");
        };
        let Some(id) = id else {
            return lang::get("horizon.pack.options.general");
@@ -192,367 +197,218 @@ impl PackOptionsUi {
        translated(&format!("config.{namespace}.section.{id}"), || readable(id))
    }

-    /// An entry's name (`config.<namespace>.<name>`) and its value's label.
-    fn parts(&self, row: u16) -> (String, Option<String>) {
-        if row == PRESETS {
-            let label = self.preset_label(self.current_preset().as_deref());
-            return (self.section_name(PRESETS), Some(label));
-        }
-        let Some(id) = self.ids.get(usize::from(row)) else {
-            return (String::new(), None);
-        };
-        let (namespace, path) = split(id);
-        let name = translated(&format!("config.{namespace}.{path}"), || readable(path));
-        let entry = &self.configs.entries()[id];
-        let value = match self.configs.get(id) {
-            Some(ConfigValue::Number(n)) => {
-                let step = match entry.kind {
-                    ConfigKind::Number { step, .. } => step,
-                    _ => 1.0,
-                };
-                let text = if step >= 1.0 && step.fract() == 0.0 {
-                    format!("{n:.0}")
-                } else {
-                    format!("{n:.2}")
-                        .trim_end_matches('0')
-                        .trim_end_matches('.')
-                        .to_owned()
-                };
-                Some(text)
-            }
-            Some(ConfigValue::Text(t)) => Some(t.clone()),
-            Some(ConfigValue::Bool(_)) | None => None,
-        };
-        let value = value.map(|v| match &entry.value_translation {
-            Some(key) if lang::has(key) => lang::tr(key, &[&v]),
-            _ => v,
-        });
-        (name, value)
-    }
-
-    /// The tooltip (`config.<namespace>.<name>.tooltip`) and the performance hint.
-    fn description(&self, row: u16) -> String {
-        let Some(id) = self.ids.get(usize::from(row)) else {
-            return String::new();
-        };
+    /// The tooltip (`config.<namespace>.<name>.tooltip`) and the performance line after it.
+    fn description(&self, id: &str) -> String {
        let (namespace, path) = split(id);
        let key = format!("config.{namespace}.{path}.tooltip");
-        let mut text = if lang::has(&key) {
+        let tooltip = if lang::has(&key) {
            lang::get(&key)
        } else {
            String::new()
        };
-        if let Some(impact) = &self.configs.entries()[id].performance_impact {
-            let level = lang::get(&format!("horizon.pack.options.impact.{impact}"));
-            let line = lang::tr("horizon.pack.options.impact", &[&level]);
-            text = if text.is_empty() {
-                line
-            } else {
-                format!("{text} {line}")
-            };
-        }
-        text
-    }
-
-    /// A slider's place (0 to 1) for a number entry.
-    fn slider(&self, row: u16) -> Option<f32> {
-        let id = self.ids.get(usize::from(row))?;
-        let ConfigKind::Number { min, max, .. } = self.configs.entries()[id].kind else {
-            return None;
-        };
-        let Some(ConfigValue::Number(n)) = self.configs.get(id) else {
-            return None;
-        };
-        Some(if max > min {
-            ((n - min) / (max - min)) as f32
-        } else {
-            0.0
-        })
-    }
-
-    fn switch(&self, row: u16) -> Option<bool> {
-        match self.configs.get(self.ids.get(usize::from(row))?)? {
-            ConfigValue::Bool(b) => Some(*b),
-            _ => None,
+        let impact = self.configs.entries()[id]
+            .performance_impact
+            .as_ref()
+            .map(|impact| {
+                let level = lang::get(&format!("horizon.pack.options.impact.{impact}"));
+                lang::tr("horizon.pack.options.impact", &[&level])
+            });
+        match impact {
+            Some(line) if tooltip.is_empty() => line,
+            Some(line) => format!("{tooltip} {line}"),
+            None => tooltip,
        }
    }

-    pub fn draw(
-        &mut self,
-        batch: &mut HudBatch,
-        atlas: &HudAtlas,
-        cursor: (f32, f32),
-        in_world: bool,
-    ) {
-        let (w, h) = (batch.width, batch.height);
-        let (cols, lines, content) = self.layout(w, h);
-        self.scroll.clamp(cols.top, cols.bottom, content);
-        shell::backdrop(batch, atlas, in_world);
-        shell::mark(
-            batch,
-            atlas,
-            &cols,
-            &lang::get("horizon.pack.options.title"),
-        );
-        shell::plate(
-            batch,
-            atlas,
-            &cols,
-            &lang::get("horizon.pack.options.title"),
-        );
-        let over_list = cursor.1 >= cols.top && cursor.1 < cols.bottom;
-        let mut described = None;
-        shell::list(
-            batch,
-            atlas,
-            &cols,
-            &lines,
-            self.scroll.amount,
-            |section| self.section_name(section),
-            |batch, row: u16, y| {
-                let [rx, ry, rw, rh] = cols.row(y);
-                let hover = over_list && ui::hovered(cursor, rx, ry, rw, rh);
-                if hover || self.dragging == Some(row) {
-                    described = Some(row);
+    /// Entry `i`'s row: a switch, a slider in its steps, a choice, or text to read.
+    fn entry_row(&self, i: u16) -> Option<Row<Item>> {
+        let id = self.ids.get(usize::from(i))?;
+        let (namespace, path) = split(id);
+        let name = translated(&format!("config.{namespace}.{path}"), || readable(path));
+        let entry = &self.configs.entries()[id];
+        let shown = |text: String| match &entry.value_translation {
+            Some(key) if lang::has(key) => lang::tr(key, &[&text]),
+            _ => text,
+        };
+        let value = match (&entry.kind, self.configs.get(id)?) {
+            (_, ConfigValue::Bool(on)) => Value::Switch(*on),
+            (&ConfigKind::Number { min, max, step }, &ConfigValue::Number(n)) => {
+                let span = max - min;
+                let stops = if step > 0.0 {
+                    (span / step).round()
+                } else {
+                    0.0
+                };
+                Value::Slider {
+                    position: if span > 0.0 {
+                        ((n - min) / span) as f32
+                    } else {
+                        0.0
+                    },
+                    steps: (stops >= 1.0).then_some(stops as u32),
+                    text: shown(number_text(n, step)),
                }
-                let (name, value) = self.parts(row);
-                let label = match &value {
-                    Some(v) => format!("{name}: {v}"),
-                    None => name.clone(),
-                };
-                let view = shell::RowView {
-                    label: &label,
-                    name: &name,
-                    value: value.as_deref(),
-                    switch: self.switch(row),
-                    slider: self.slider(row),
-                    live: true,
-                    hover,
-                    focused: false,
-                    held: self.dragging == Some(row),
-                    key: None,
-                };
-                shell::row(batch, atlas, &cols, y, &view);
-            },
-        );
-        shell::scroller(batch, atlas, &cols, content, self.scroll.amount);
-        // The strip: the pointed-at entry's tooltip.
-        let [x, y, ..] = cols.dock;
-        style::panel(batch, atlas, cols.dock);
-        if let Some(row) = described {
-            let name = Text::literal(self.parts(row).0);
-            batch.text_styled(atlas, &name, x + 12.0, y + 8.0, style::WHITE, true);
-            shell::dock_note(batch, atlas, &cols, self.description(row), style::GREY);
-        }
-        let mut foot = vec![(cols.button(0), "gui.done", Some(Declared::Done))];
-        if self
-            .configs
-            .chosen()
-            .iter()
-            .any(|(id, _)| self.ids.contains(id))
-        {
-            foot.push((cols.button(1), "controls.reset", None));
-        }
-        for (rect, key, declared) in foot {
-            if let Some(declared) = declared {
-                crate::widgets::declare_action(declared, rect, true);
            }
-            let label = Text::literal(lang::get(key));
-            shell::foot_button(batch, atlas, rect, &label, cursor, (false, true));
-        }
+            (ConfigKind::Text { allowed }, ConfigValue::Text(t)) if !allowed.is_empty() => {
+                Value::Choice(shown(t.clone()))
+            }
+            (_, value) => Value::Read(shown(match value {
+                ConfigValue::Number(n) => number_text(*n, 1.0),
+                ConfigValue::Text(t) => t.clone(),
+                ConfigValue::Bool(b) => b.to_string(),
+            })),
+        };
+        Some(Row::new(Item::Entry(i), name, value).about(self.description(id)))
    }

-    /// A press (or a drag with `drag`) at `(x, y)`; `back` turns a cycle backwards.
-    pub fn click(
-        &mut self,
-        (x, y): (f32, f32),
-        (w, h): (f32, f32),
-        drag: bool,
-        back: bool,
-    ) -> Vec<Action> {
-        let (cols, lines, content) = self.layout(w, h);
-        let at = |[rx, ry, rw, rh]: [f32; 4]| ui::hovered((x, y), rx, ry, rw, rh);
-        if drag {
-            if self.scroll.held() {
-                self.scroll.drag(y, cols.top, cols.bottom, content);
-            } else if let Some(row) = self.dragging {
-                self.set_slider(row, cols.slider_at(x));
-                return vec![Action::SliderDrag];
-            }
-            return Vec::new();
+    /// The rows for the whole pack: its presets, when it has some, and Reset all.
+    fn whole_pack(&self) -> Group<Item> {
+        let mut rows = Vec::new();
+        if !self.configs.presets().is_empty() {
+            let key = format!("{}.presets", self.presets_namespace());
+            let name = translated(&key, || lang::get("horizon.pack.options.presets"));
+            let label = self.preset_label(self.current_preset().as_deref());
+            rows.push(
+                Row::new(Item::Presets, name, Value::Choice(label)).about(lang::get(PRESETS_ABOUT)),
+            );
        }
-        if cols.scrolls()
-            && self
-                .scroll
-                .press((x, y), cols.bar_x(), cols.top, cols.bottom, content)
-        {
-            return Vec::new();
+        let at_defaults = self.configs.chosen().is_empty();
+        let reset = Row::new(Item::ResetAll, lang::get(RESET_ALL), Value::Press)
+            .about(lang::get(RESET_ABOUT))
+            .blocked(at_defaults.then(|| lang::get(AT_DEFAULTS)));
+        rows.push(reset);
+        Group {
+            name: WHOLE_PACK,
+            rows,
        }
-        if at(cols.button(0)) {
-            return vec![Action::ButtonClick, Action::Done];
-        }
-        if at(cols.button(1)) {
-            self.reset();
-            return vec![Action::ButtonClick];
-        }
-        if y < cols.top || y >= cols.bottom {
-            return Vec::new();
-        }
-        let Some(row) = lines.iter().find_map(|line| {
-            let row = line.setting?;
-            at(cols.row(cols.top + line.y - self.scroll.amount)).then_some(row)
-        }) else {
-            return Vec::new();
-        };
-        if row == PRESETS {
-            self.cycle_preset(back);
-            return vec![Action::ButtonClick];
-        }
-        let Some(id) = self.ids.get(usize::from(row)).cloned() else {
-            return Vec::new();
-        };
-        let entry = self.configs.entries()[&id].clone();
-        match (&entry.kind, self.configs.get(&id).cloned()) {
-            (ConfigKind::Number { .. }, _) => {
-                self.dragging = Some(row);
-                self.set_slider(row, cols.slider_at(x));
-                return vec![Action::SliderDrag];
-            }
-            (ConfigKind::Bool, Some(ConfigValue::Bool(b))) => {
-                self.set(&id, ConfigValue::Bool(!b));
-            }
-            (ConfigKind::Text { allowed }, Some(ConfigValue::Text(t))) if !allowed.is_empty() => {
-                let i = allowed.iter().position(|a| *a == t).unwrap_or(0);
-                let n = allowed.len();
-                let next = if back { (i + n - 1) % n } else { (i + 1) % n };
-                self.set(&id, ConfigValue::Text(allowed[next].clone()));
-            }
-            _ => return Vec::new(),
-        }
-        vec![Action::ButtonClick]
    }

    fn set(&mut self, id: &str, value: ConfigValue) {
-        let before = self.configs.get(id).cloned();
        self.configs.set(id, value);
-        if self.configs.get(id).cloned() != before {
-            self.changed = true;
-        }
-    }
-
-    /// Number entry `row` at slider place `at` (0 to 1).
-    fn set_slider(&mut self, row: u16, at: f32) {
-        let Some(id) = self.ids.get(usize::from(row)).cloned() else {
-            return;
-        };
-        if let ConfigKind::Number { min, max, .. } = self.configs.entries()[&id].kind {
-            self.set(&id, ConfigValue::Number(min + f64::from(at) * (max - min)));
-        }
+        self.revision += 1;
    }

    /// Every entry back to its default.
    fn reset(&mut self) {
-        let defaults: Vec<_> = self
-            .configs
-            .entries()
-            .iter()
+        let defaults: Vec<_> = (self.configs.entries().iter())
            .map(|(id, e)| (id.clone(), e.default.clone()))
            .collect();
        for (id, value) in defaults {
            self.set(&id, value);
        }
    }
+}

-    /// The pointer lets go.
-    pub fn release(&mut self) {
-        self.scroll.release();
-        self.dragging = None;
+impl shell::Screen for PackOptionsScreen {
+    type Page = u16;
+    type Row = Item;
+    fn title(&self) -> &'static str {
+        TITLE
    }
-
-    /// The mouse wheel scrolls the list.
-    pub fn scroll(&mut self, (w, h): (f32, f32), amount: f32) {
-        let (cols, _, content) = self.layout(w, h);
-        self.scroll
-            .wheel(amount, 18.0, cols.top, cols.bottom, content);
+    fn note_lines(&self) -> usize {
+        NOTE_LINES
+    }
+    /// The rows read only the screen's own entries, which change through it alone.
+    fn stamp(&self, _s: &Settings) -> u64 {
+        self.revision
+    }
+    /// A page per section; the first starts with the rows for the whole pack.
+    fn sheets(&self, _s: &Settings) -> Vec<Sheet<u16, Item>> {
+        let about = lang::get(PACK_SETTINGS);
+        let mut sheets = Vec::new();
+        for (i, (_, entries)) in self.sections.iter().enumerate() {
+            let rows = entries.iter().filter_map(|&e| self.entry_row(e)).collect();
+            let mut groups = vec![Group {
+                name: PACK_OPTIONS,
+                rows,
+            }];
+            if i == 0 {
+                groups.insert(0, self.whole_pack());
+            }
+            sheets.push(Sheet::new(
+                i as u16,
+                self.section_name(i),
+                about.clone(),
+                groups,
+            ));
+        }
+        if sheets.is_empty() {
+            let groups = vec![self.whole_pack()];
+            sheets.push(Sheet::new(0, self.section_name(0), about, groups));
+        }
+        sheets
+    }
+    /// A switch flips, a choice and the presets step (back with Shift, or Left), Reset all
+    /// resets.
+    fn press(&mut self, _s: &mut Settings, item: Item, back: bool) -> Vec<Output> {
+        let i = match item {
+            Item::Presets => {
+                self.cycle_preset(back);
+                return Vec::new();
+            }
+            Item::ResetAll => {
+                self.reset();
+                return Vec::new();
+            }
+            Item::Entry(i) => i,
+        };
+        let Some(id) = self.ids.get(usize::from(i)).cloned() else {
+            return Vec::new();
+        };
+        let kind = self.configs.entries()[&id].kind.clone();
+        match (kind, self.configs.get(&id).cloned()) {
+            (_, Some(ConfigValue::Bool(on))) => self.set(&id, ConfigValue::Bool(!on)),
+            (ConfigKind::Text { allowed }, Some(ConfigValue::Text(t))) if !allowed.is_empty() => {
+                let at = allowed.iter().position(|a| *a == t).unwrap_or(0);
+                let n = allowed.len();
+                let next = if back { (at + n - 1) % n } else { (at + 1) % n };
+                self.set(&id, ConfigValue::Text(allowed[next].clone()));
+            }
+            _ => {}
+        }
+        Vec::new()
+    }
+    /// A slider moves its entry to the step nearest it (`Configs::set` snaps it).
+    fn slide(&mut self, _s: &mut Settings, item: Item, position: f32) {
+        let Item::Entry(i) = item else { return };
+        let Some(id) = self.ids.get(usize::from(i)).cloned() else {
+            return;
+        };
+        if let ConfigKind::Number { min, max, .. } = self.configs.entries()[&id].kind {
+            let value = min + f64::from(position.clamp(0.0, 1.0)) * (max - min);
+            self.set(&id, ConfigValue::Number(value));
+        }
+    }
+    /// With the "Scroll wheel changes settings" extra, the wheel steps a choice and the presets.
+    fn wheel_step(&mut self, s: &mut Settings, item: Item, back: bool) -> Option<Vec<Output>> {
+        let steps = match item {
+            Item::Presets => true,
+            Item::Entry(i) => self
+                .entry_row(i)
+                .is_some_and(|row| matches!(row.value, Value::Choice(_))),
+            Item::ResetAll => false,
+        };
+        if !steps {
+            return None;
+        }
+        let mut outputs = vec![Output::Event(crate::options_ui::Event::ButtonClick)];
+        outputs.extend(self.press(s, item, back));
+        Some(outputs)
+    }
+    fn undoes(&self) -> bool {
+        true
+    }
+    /// The entries as the screen opened with them.
+    fn undo(&mut self, _s: &mut Settings, _before: &Settings) -> Vec<Output> {
+        self.configs = self.opened.clone();
+        self.revision += 1;
+        Vec::new()
+    }
+    /// Undo shows exactly while an entry differs from how the screen opened.
+    fn differs(&self, _s: &Settings, _before: &Settings) -> Option<bool> {
+        Some(self.configs != self.opened)
    }
 }

 #[cfg(test)]
-mod tests {
-    use super::*;
-
-    fn configs() -> Configs {
-        let mut c = Configs::default();
-        c.add_entry(
-            "p:fog".into(),
-            &serde_json::json!({"default_value": 0.5, "section": "sky", "section_order": 2}),
-        );
-        c.add_entry("p:rain".into(), &serde_json::json!({"default_value": "drops", "allowed_values": ["drops", "streaks"], "section": "weather", "section_order": 1}));
-        c.add_entry(
-            "p:birds".into(),
-            &serde_json::json!({"default_value": true}),
-        );
-        c
-    }
-
-    #[test]
-    fn sections_sort_by_their_order_and_the_unsectioned_last() {
-        let ui = PackOptionsUi::open(configs());
-        let order: Vec<_> = ui.sections.iter().map(|(s, _)| s.as_deref()).collect();
-        assert_eq!(order, [Some("weather"), Some("sky"), None]);
-    }
-
-    #[test]
-    fn rows_switch_cycle_and_slide() {
-        let mut ui = PackOptionsUi::open(configs());
-        let size = (480.0, 270.0);
-        let (cols, lines, _) = ui.layout(size.0, size.1);
-        let ids = ui.ids.clone();
-        let point = |id: &str| {
-            let row = ids.iter().position(|i| i == id).unwrap() as u16;
-            let line = lines.iter().find(|l| l.setting == Some(row)).unwrap();
-            let [x, y, w, h] = cols.row(cols.top + line.y);
-            (x + w - 4.0, y + h / 2.0)
-        };
-        let (birds, rain) = (point("p:birds"), point("p:rain"));
-        ui.click(birds, size, false, false);
-        assert_eq!(ui.configs.get("p:birds"), Some(&ConfigValue::Bool(false)));
-        ui.click(rain, size, false, false);
-        assert_eq!(
-            ui.configs.get("p:rain"),
-            Some(&ConfigValue::Text("streaks".into()))
-        );
-        // The slider's far right end is its maximum.
-        let fog = point("p:fog");
-        let (tx, tw) = cols.track();
-        ui.click((tx + tw, fog.1), size, false, false);
-        ui.release();
-        assert_eq!(ui.configs.get("p:fog"), Some(&ConfigValue::Number(1.0)));
-        assert!(ui.changed);
-        assert_eq!(ui.configs.chosen().len(), 3);
-        ui.reset();
-        assert!(ui.configs.chosen().is_empty());
-    }
-
-    #[test]
-    fn the_presets_row_cycles_the_pack_wide_presets_and_shows_custom_otherwise() {
-        let mut c = Configs::default();
-        let entry = |default: f64, fast: f64, pretty: f64| serde_json::json!({"default_value": default, "presets": {"fast": fast, "pretty": pretty}});
-        c.add_entry("p:fog".into(), &entry(0.5, 0.0, 1.0));
-        c.add_entry("p:dust".into(), &entry(0.5, 0.0, 0.8));
-        let mut ui = PackOptionsUi::open(c);
-        // The defaults are no preset.
-        assert_eq!(ui.current_preset(), None);
-        ui.cycle_preset(false);
-        assert_eq!(ui.current_preset().as_deref(), Some("fast"));
-        assert_eq!(ui.configs.get("p:fog"), Some(&ConfigValue::Number(0.0)));
-        ui.cycle_preset(false);
-        assert_eq!(ui.current_preset().as_deref(), Some("pretty"));
-        ui.cycle_preset(true);
-        assert_eq!(ui.current_preset().as_deref(), Some("fast"));
-        // One value off the preset: custom again.
-        ui.set("p:dust", ConfigValue::Number(0.3));
-        assert_eq!(ui.current_preset(), None);
-        assert!(ui.changed);
-    }
-}
+mod tests;
@@ -0,0 +1,281 @@
+use super::*;
+use crate::options_ui::Event;
+use crate::settings_shell::{Columns, Hosted, Screen as _, Shell, Target};
+use winit::keyboard::KeyCode as K;
+
+const SIZE: (f32, f32) = (854.0, 480.0);
+
+/// Fog (a number) under Sky, rain (a list of values) under Weather, birds (a boolean) in no
+/// section.
+fn configs() -> Configs {
+    let mut c = Configs::default();
+    c.add_entry(
+        "p:fog".into(),
+        &serde_json::json!({"default_value": 0.5, "section": "sky", "section_order": 2}),
+    );
+    c.add_entry("p:rain".into(), &serde_json::json!({"default_value": "drops", "allowed_values": ["drops", "streaks"], "section": "weather", "section_order": 1}));
+    c.add_entry(
+        "p:birds".into(),
+        &serde_json::json!({"default_value": true}),
+    );
+    c
+}
+
+/// Two entries with the pack-wide presets `fast` and `pretty`.
+fn with_presets() -> Configs {
+    let mut c = Configs::default();
+    let entry = |default: f64, fast: f64, pretty: f64| serde_json::json!({"default_value": default, "presets": {"fast": fast, "pretty": pretty}});
+    c.add_entry("p:fog".into(), &entry(0.5, 0.0, 1.0));
+    c.add_entry("p:dust".into(), &entry(0.5, 0.0, 0.8));
+    c
+}
+
+fn shell_of(configs: Configs) -> Shell<PackOptionsScreen> {
+    let mut shell = Shell::default();
+    shell.screen = PackOptionsScreen::open(configs);
+    shell
+}
+
+/// The row of entry `id`, and the page it is on.
+fn entry(shell: &Shell<PackOptionsScreen>, id: &str) -> (u16, Item) {
+    let i = shell.screen.ids.iter().position(|e| e == id).unwrap() as u16;
+    let page = shell.screen.sections.iter().position(|s| s.1.contains(&i));
+    (page.unwrap() as u16, Item::Entry(i))
+}
+
+fn press(shell: &mut Shell<PackOptionsScreen>, s: &mut Settings, item: Item) -> Vec<Output> {
+    let at = shell.point_at(s, SIZE, item);
+    shell.click(s, at, SIZE, false, false, false)
+}
+
+fn value<'a>(shell: &'a Shell<PackOptionsScreen>, id: &str) -> Option<&'a ConfigValue> {
+    shell.screen.configs.get(id)
+}
+
+#[test]
+fn sections_sort_by_their_order_and_the_unsectioned_last() {
+    let screen = PackOptionsScreen::open(configs());
+    let order: Vec<_> = screen.sections.iter().map(|(s, _)| s.as_deref()).collect();
+    assert_eq!(order, [Some("weather"), Some("sky"), None]);
+    // Each section is a page, the first one holding Reset all before its entries.
+    let sheets = screen.sheets(&Settings::default());
+    let names: Vec<_> = sheets.iter().map(|p| p.name.as_str()).collect();
+    assert_eq!(names, ["Weather", "Sky", "horizon.pack.options.general"]);
+    let first: Vec<Vec<Item>> = (sheets[0].groups.iter())
+        .map(|g| g.rows.iter().map(|r| r.id).collect())
+        .collect();
+    let rain = screen.ids.iter().position(|e| e == "p:rain").unwrap() as u16;
+    assert_eq!(first, [vec![Item::ResetAll], vec![Item::Entry(rain)]]);
+}
+
+#[test]
+fn rows_switch_cycle_and_slide() {
+    let mut s = Settings::default();
+    let mut shell = shell_of(configs());
+    let (page, birds) = entry(&shell, "p:birds");
+    shell.show(page);
+    assert_eq!(
+        press(&mut shell, &mut s, birds)[0],
+        Output::Event(Event::ButtonClick)
+    );
+    assert_eq!(value(&shell, "p:birds"), Some(&ConfigValue::Bool(false)));
+    let (page, rain) = entry(&shell, "p:rain");
+    shell.show(page);
+    press(&mut shell, &mut s, rain);
+    let streaks = ConfigValue::Text("streaks".into());
+    assert_eq!(value(&shell, "p:rain"), Some(&streaks));
+    // The slider's far right end is its maximum.
+    let (page, fog) = entry(&shell, "p:fog");
+    shell.show(page);
+    let at = shell.point_at(&s, SIZE, fog);
+    let (track, width) = Columns::of(SIZE.0, SIZE.1).track();
+    shell.click(&mut s, (track + width, at.1), SIZE, false, false, false);
+    shell.release();
+    assert_eq!(value(&shell, "p:fog"), Some(&ConfigValue::Number(1.0)));
+    assert_eq!(shell.screen.configs.chosen().len(), 3);
+    // Reset all, on the first page, puts them all back, and is greyed once they are.
+    shell.show(0);
+    press(&mut shell, &mut s, Item::ResetAll);
+    assert!(shell.screen.configs.chosen().is_empty());
+    let sheets = shell.screen.sheets(&s);
+    assert!(!sheets[0].groups[0].rows[0].live);
+}
+
+#[test]
+fn the_presets_row_cycles_the_pack_wide_presets_and_shows_custom_otherwise() {
+    let mut screen = PackOptionsScreen::open(with_presets());
+    // The defaults are no preset.
+    assert_eq!(screen.current_preset(), None);
+    screen.cycle_preset(false);
+    assert_eq!(screen.current_preset().as_deref(), Some("fast"));
+    assert_eq!(screen.configs.get("p:fog"), Some(&ConfigValue::Number(0.0)));
+    screen.cycle_preset(false);
+    assert_eq!(screen.current_preset().as_deref(), Some("pretty"));
+    screen.cycle_preset(true);
+    assert_eq!(screen.current_preset().as_deref(), Some("fast"));
+    // One value off the preset: custom again.
+    screen.set("p:dust", ConfigValue::Number(0.3));
+    assert_eq!(screen.current_preset(), None);
+    let presets = &screen.sheets(&Settings::default())[0].groups[0].rows[0];
+    assert_eq!(presets.id, Item::Presets);
+    let custom = lang::get("horizon.pack.options.presets.custom");
+    assert_eq!(presets.value, Value::Choice(custom));
+}
+
+#[test]
+fn left_and_right_step_the_presets() {
+    let mut s = Settings::default();
+    let mut shell = shell_of(with_presets());
+    shell.set_focus(Some(Target::Row(Item::Presets)));
+    shell.key(&mut s, K::ArrowRight, None, false, SIZE);
+    assert_eq!(shell.screen.current_preset().as_deref(), Some("fast"));
+    shell.key(&mut s, K::ArrowRight, None, false, SIZE);
+    assert_eq!(shell.screen.current_preset().as_deref(), Some("pretty"));
+    shell.key(&mut s, K::ArrowLeft, None, false, SIZE);
+    assert_eq!(shell.screen.current_preset().as_deref(), Some("fast"));
+    assert_eq!(shell.focused_row(), Some(Item::Presets));
+}
+
+#[test]
+fn sliders_stop_at_the_entrys_step() {
+    let mut c = Configs::default();
+    let json = serde_json::json!({"default_value": 4.0, "min": 0.0, "max": 10.0, "step": 2.0});
+    c.add_entry("p:clouds".into(), &json);
+    let mut s = Settings::default();
+    let mut shell = shell_of(c);
+    let row = &shell.screen.sheets(&s)[0].groups[1].rows[0];
+    let stops = Value::Slider {
+        position: 0.4,
+        steps: Some(5),
+        text: "4".into(),
+    };
+    assert_eq!(row.value, stops);
+    // A press a little past the middle of the track lands on the step nearest it.
+    let at = shell.point_at(&s, SIZE, Item::Entry(0));
+    let (track, width) = Columns::of(SIZE.0, SIZE.1).track();
+    shell.click(
+        &mut s,
+        (track + width * 0.55, at.1),
+        SIZE,
+        false,
+        false,
+        false,
+    );
+    shell.release();
+    assert_eq!(value(&shell, "p:clouds"), Some(&ConfigValue::Number(6.0)));
+    // Held by the press, Right goes one step on and Left one back.
+    shell.set_focus(Some(Target::Row(Item::Entry(0))));
+    shell.key(&mut s, K::ArrowRight, None, false, SIZE);
+    assert_eq!(value(&shell, "p:clouds"), Some(&ConfigValue::Number(8.0)));
+    shell.key(&mut s, K::ArrowLeft, None, false, SIZE);
+    shell.key(&mut s, K::ArrowLeft, None, false, SIZE);
+    assert_eq!(value(&shell, "p:clouds"), Some(&ConfigValue::Number(4.0)));
+}
+
+/// A language with the pack's own strings: a name, a section and a tooltip.
+struct PackLang;
+impl lang::ResourceSource for PackLang {
+    fn read(&self, path: &str) -> Option<Vec<u8>> {
+        (path == "assets/minecraft/lang/en_us.json").then(|| {
+            let strings = serde_json::json!({
+                "config.minecraft.haze": "Haze",
+                "config.minecraft.haze.tooltip": "Thickens the distant air.",
+                "config.minecraft.section.sky": "Sky and fog",
+            });
+            serde_json::to_vec(&strings).unwrap()
+        })
+    }
+}
+
+fn haze() -> Configs {
+    let mut c = configs();
+    let json =
+        serde_json::json!({"default_value": false, "section": "sky", "performance_impact": "high"});
+    c.add_entry("minecraft:haze".into(), &json);
+    c
+}
+
+#[test]
+fn the_search_finds_an_entry_by_its_tooltip_and_the_strip_has_its_impact() {
+    let language = lang::Language::load(&[&PackLang], "en_us");
+    lang::scoped(language, || {
+        let s = Settings::default();
+        let mut shell = shell_of(haze());
+        let (page, haze) = entry(&shell, "minecraft:haze");
+        shell.set_search("distant air");
+        assert_eq!(shell.listed(&s, SIZE), [(page, haze)]);
+        let sheets = shell.screen.sheets(&s);
+        assert_eq!(sheets[usize::from(page)].name, "Sky and fog");
+        let row = sheets.iter().flat_map(|p| &p.groups).flat_map(|g| &g.rows);
+        let row = row.into_iter().find(|r| r.id == haze).unwrap();
+        assert_eq!(row.name, "Haze");
+        assert_eq!(
+            row.about,
+            "Thickens the distant air. Performance impact: high"
+        );
+    });
+}
+
+#[test]
+fn tab_reaches_every_row_of_every_page() {
+    let mut s = Settings::default();
+    let mut shell = shell_of(haze());
+    let pages = shell.screen.sheets(&s).len() as u16;
+    let mut seen = Vec::new();
+    for page in 0..pages {
+        shell.show(page);
+        shell.set_focus(None);
+        for _ in 0..8 {
+            shell.key(&mut s, K::Tab, None, false, SIZE);
+            if let Some(row) = shell.focused_row()
+                && !seen.contains(&row)
+            {
+                seen.push(row);
+            }
+        }
+    }
+    // Reset all is greyed at the defaults; every entry is reached.
+    let mut entries: Vec<Item> = (0..shell.screen.ids.len() as u16)
+        .map(Item::Entry)
+        .collect();
+    seen.sort_by_key(|item| format!("{item:?}"));
+    entries.sort_by_key(|item| format!("{item:?}"));
+    assert_eq!(seen, entries);
+}
+
+#[test]
+fn undo_puts_the_entries_back_and_then_leaving_sends_nothing() {
+    let mut s = Settings::default();
+    let mut shell = shell_of(configs());
+    let (page, birds) = entry(&shell, "p:birds");
+    shell.show(page);
+    press(&mut shell, &mut s, birds);
+    assert!(shell.foot_at(&s, SIZE).iter().any(|f| f.0 == Target::Undo));
+    assert!(shell.screen.finished().is_some());
+    let undo = shell
+        .foot_at(&s, SIZE)
+        .into_iter()
+        .find(|f| f.0 == Target::Undo);
+    let [x, y, w, h] = undo.unwrap().1;
+    shell.click(
+        &mut s,
+        (x + w / 2.0, y + h / 2.0),
+        SIZE,
+        false,
+        false,
+        false,
+    );
+    assert_eq!(value(&shell, "p:birds"), Some(&ConfigValue::Bool(true)));
+    assert!(!shell.foot_at(&s, SIZE).iter().any(|f| f.0 == Target::Undo));
+    assert_eq!(shell.screen.finished(), None);
+    // Stepped there and back by hand, it sends nothing either.
+    press(&mut shell, &mut s, birds);
+    press(&mut shell, &mut s, birds);
+    assert_eq!(shell.screen.finished(), None);
+    press(&mut shell, &mut s, birds);
+    let Some(Event::PackOptions { entries, chosen }) = shell.screen.finished() else {
+        panic!("a change is sent");
+    };
+    assert_eq!(entries.len(), 3);
+    assert_eq!(chosen.get("p:birds"), Some(&ConfigValue::Bool(false)));
+}
@@ -677,7 +677,7 @@ impl PackScreen {
            return action;
        }
        if self.search.contains(x, y) {
-            self.search.click(m, x, false);
+            self.search.click(m, x, false, false);
            self.set_focus(Focus::Search);
            return Action::None;
        }
@@ -1100,6 +1100,9 @@ impl PackScreen {
            0,
        );
        self.search.draw(&mut out, m, blink_ms, None);
+        if self.browser.is_none() && self.search.contains(f64::from(mouse.0), f64::from(mouse.1)) {
+            crate::widgets::text_cursor(true, true);
+        }
        for side in 0..2 {
            self.draw_list(&mut out, m, side, mouse);
        }
@@ -1134,7 +1137,7 @@ impl PackScreen {
            if d::inside(point, qx, qy, BROWSER_SEARCH_W, 18) {
                self.browser_search.x = qx;
                self.browser_search.y = qy;
-                self.browser_search.click(m, x, false);
+                self.browser_search.click(m, x, false, false);
                self.browser_focus = true;
                return Some(Action::None);
            }
@@ -1302,6 +1305,9 @@ impl PackScreen {
        field.x = qx;
        field.y = qy;
        field.draw(out, m, 0, None);
+        if field.contains(f64::from(mouse.0), f64::from(mouse.1)) {
+            crate::widgets::text_cursor(true, true);
+        }
        let (sbx, sby) = self.browser_search_button();
        d::button(
            out,
@@ -468,17 +468,20 @@ fn read_meta(source: &Source) -> Option<serde_json::Value> {
 /// file with a comment after the closing brace. Gson reads past a UTF-8 byte order mark;
 /// serde_json rejects it.
 pub(crate) fn parse_meta(bytes: &[u8]) -> Option<serde_json::Value> {
-    first_json(bytes)
+    first_json(bytes).ok()
 }
-
-/// Reads the first JSON value from resource metadata, matching Gson's
-/// `JsonReader` (which ignores a trailing signature or comment). Resource
-/// packs commonly append such text to texture metadata as well as pack.mcmeta.
-pub(crate) fn first_json(bytes: &[u8]) -> Option<serde_json::Value> {
-    serde_json::Deserializer::from_slice(bytes.strip_prefix(b"\xEF\xBB\xBF").unwrap_or(bytes))
+/// The first JSON value of a `.mcmeta` file, as `ResourceMetadata.fromJsonStream` reads it:
+/// Gson's `TypeAdapter.read` stops after the value, so text after it (packs leave `//` notes
+/// there) is never read, and a UTF-8 byte order mark is skipped.
+pub(crate) fn first_json<T: serde::de::DeserializeOwned>(bytes: &[u8]) -> serde_json::Result<T> {
+    let bytes = bytes.strip_prefix(b"\xEF\xBB\xBF").unwrap_or(bytes);
+    match serde_json::Deserializer::from_slice(bytes)
        .into_iter()
-        .next()?
-        .ok()
+        .next()
+    {
+        Some(value) => value,
+        None => Err(serde::de::Error::custom("empty metadata")),
+    }
 }
 /// A pack's Polytone config entries (`assets/<namespace>/polytone/config_entries/<name>.json`,
 /// in the pack's base, not its overlays) at their default values.
@@ -827,13 +830,6 @@ fn build_overlay_uncached(
    }
    // Vanilla sits below every pack, so filters hide its files too.
    let filters: Vec<&Filter> = packs.iter().flat_map(|p| &p.filter).collect();
-    let touched_dirs: BTreeSet<String> = files
-        .keys()
-        .flat_map(|f| {
-            let parts: Vec<&str> = f.split('/').collect();
-            (1..parts.len()).map(move |n| parts[..n].join("/"))
-        })
-        .collect();
    let zips: Vec<Option<Zip>> = packs
        .iter()
        .map(|p| {
@@ -882,6 +878,21 @@ fn build_overlay_uncached(
            merged.insert(name.clone(), bytes);
        }
    }
+    add_sprite_renames(
+        vanilla,
+        &merged,
+        &filters,
+        &mut files,
+        &mut hidden,
+        dependencies,
+    );
+    let touched_dirs: BTreeSet<String> = files
+        .keys()
+        .flat_map(|f| {
+            let parts: Vec<&str> = f.split('/').collect();
+            (1..parts.len()).map(move |n| parts[..n].join("/"))
+        })
+        .collect();
    /// A zip entry to write: its pack, its name in the zip and where it goes.
    type Extract<'a> = (usize, &'a str, PathBuf);
    #[allow(clippy::too_many_arguments)]
@@ -1032,6 +1043,123 @@ fn build_overlay_uncached(
    }
    extracted
 }
+/// `SingleFile` with a `sprite`: the atlas holds the resource's pixels, and the resource's
+/// `.mcmeta`, under the sprite's id. Every other sprite of the blocks and items atlases is its
+/// texture's own id, and the loaders read a model's sprite from `textures/<sprite>.png`, so the
+/// overlay gives a renamed sprite that file. ItemsAdder and Nexo packs name their models'
+/// textures only through these renames (#14485).
+///
+/// A sprite gets its resource's file only when the whole source list, in order, ends on the
+/// rename (`SpriteSourceList.list`: a later source of the same id replaces it), when the other
+/// atlas, which reads the same file, lists it from that resource too or not at all, and when it
+/// has no texture of its own. A texture that is there may be read as itself (another source's
+/// resource, an unstitched or paletted sprite's input), so no alias ever replaces one; such a
+/// sprite draws its own texture, as before aliases.
+fn add_sprite_renames(
+    vanilla: &Path,
+    merged: &BTreeMap<String, Vec<u8>>,
+    filters: &[&Filter],
+    files: &mut BTreeMap<String, (usize, Provided)>,
+    hidden: &mut BTreeSet<String>,
+    dependencies: &mut cache::Dependencies,
+) {
+    use crate::atlas_sources::{
+        SpriteOrigin, SpriteSource, decode, list, list_textures, texture_path,
+    };
+    let png = |id: &str| {
+        texture_path(Path::new(""), id, "textures")
+            .to_string_lossy()
+            .replace('\\', "/")
+    };
+    let atlases: Vec<_> = ["blocks", "items"]
+        .into_iter()
+        .filter_map(|atlas| merged.get(&format!("assets/minecraft/atlases/{atlas}.json")))
+        .filter_map(|bytes| decode(std::str::from_utf8(bytes).ok()?))
+        .collect();
+    let renamed = |source: &SpriteSource| matches!(source, SpriteSource::Single { resource, sprite: Some(sprite) } if sprite != resource);
+    if !atlases.iter().flatten().any(renamed) {
+        return;
+    }
+    // The textures a source can list: the packs' and vanilla's the packs leave visible.
+    let mut textures: Vec<String> = list_textures(vanilla)
+        .into_iter()
+        .filter(|id| {
+            let name = png(id);
+            !hidden.contains(&name) && !filters.iter().any(|f| f.blocks(&name))
+        })
+        .chain(files.keys().filter_map(|name| {
+            let (namespace, rest) = name.strip_prefix("assets/")?.split_once('/')?;
+            let path = rest.strip_prefix("textures/")?.strip_suffix(".png")?;
+            Some(format!("{namespace}:{path}"))
+        }))
+        .collect();
+    textures.sort();
+    textures.dedup();
+    // Each sprite's resource, `None` where an atlas lists it any other way.
+    let mut renames: BTreeMap<String, Option<String>> = BTreeMap::new();
+    for sources in &atlases {
+        for (sprite, origin) in list(sources, &textures) {
+            let from = match origin {
+                SpriteOrigin::File(resource) if resource != sprite => Some(resource),
+                _ => None,
+            };
+            renames
+                .entry(sprite)
+                .and_modify(|seen| {
+                    if *seen != from {
+                        *seen = None;
+                    }
+                })
+                .or_insert(from);
+        }
+    }
+    let renames = renames
+        .into_iter()
+        .filter(|(sprite, _)| textures.binary_search(sprite).is_err())
+        .filter_map(|(sprite, resource)| Some((png(&resource?), png(&sprite))));
+    // Each resource is the file the packs give, never another rename's sprite.
+    let mut found = Vec::new();
+    for (from, to) in renames {
+        // `texture_path` names an id that would leave the root as a file that is never there.
+        if !stays_inside(&from) || !stays_inside(&to) {
+            continue;
+        }
+        let from_meta = format!("{from}.mcmeta");
+        // A pack's texture with its own `.mcmeta`, or vanilla's below every pack.
+        let (file, meta) = match files.get(&from) {
+            Some(file) => (file.clone(), files.get(&from_meta).cloned()),
+            None => {
+                let (path, meta_path) = (vanilla.join(&from), vanilla.join(&from_meta));
+                dependencies.file(&path);
+                dependencies.file(&meta_path);
+                if !path.is_file() || filters.iter().any(|f| f.blocks(&from)) {
+                    continue;
+                }
+                // `createStackMetadataFinder`: a pack's filter hides vanilla's `.mcmeta` too.
+                let meta = files.get(&from_meta).cloned().or_else(|| {
+                    (meta_path.is_file() && !filters.iter().any(|f| f.blocks(&from_meta)))
+                        .then(|| (0, (Some(meta_path), from_meta.clone())))
+                });
+                ((0, (Some(path), from.clone())), meta)
+            }
+        };
+        found.push((to, file, meta));
+    }
+    for (to, file, meta) in found {
+        let to_meta = format!("{to}.mcmeta");
+        files.insert(to, file);
+        match meta {
+            Some(meta) => {
+                hidden.remove(&to_meta);
+                files.insert(to_meta, meta);
+            }
+            None => {
+                files.remove(&to_meta);
+                hidden.insert(to_meta);
+            }
+        }
+    }
+}
 /// The most the zip packs in `packs` may unpack to in one overlay: 16 times their size on disk
 /// (real packs are mostly PNGs and JSON, a few times smaller zipped at most), at least 64 MiB
 /// for a small pack of text, and never past 8 GiB.
@@ -1906,6 +2034,94 @@ mod tests {
        let _ = fs::remove_dir_all(base);
    }
    #[test]
+    fn a_renamed_atlas_sprite_reads_its_resource() {
+        let base =
+            std::env::temp_dir().join(format!("horizon-sprite-rename-{}", std::process::id()));
+        let _ = fs::remove_dir_all(&base);
+        let write = |path: PathBuf, bytes: &[u8]| {
+            fs::create_dir_all(path.parent().unwrap()).unwrap();
+            fs::write(path, bytes).unwrap();
+        };
+        let vanilla = base.join("vanilla");
+        let textures = vanilla.join("assets/minecraft/textures");
+        let animation = b"{\"animation\":{}}";
+        write(textures.join("block/sea_lantern.png"), b"lantern");
+        write(textures.join("block/sea_lantern.png.mcmeta"), animation);
+        write(textures.join("item/stick.png"), b"vanilla stick");
+        write(textures.join("item/stick.png.mcmeta"), animation);
+        let meta = br#"{"pack":{"description":"d","pack_format":97}}"#;
+        let pack = base.join("packs/IA");
+        write(pack.join("pack.mcmeta"), meta);
+        write(pack.join("assets/iageneric/textures/item/box.png"), b"box");
+        // An ItemsAdder pack's items atlas: its models name only the `ia:` sprites.
+        write(
+            pack.join("assets/minecraft/atlases/items.json"),
+            br#"{"sources":[
+                {"type":"single","resource":"iageneric:item/box","sprite":"ia:0"},
+                {"type":"single","resource":"minecraft:block/sea_lantern","sprite":"ia:1199"},
+                {"type":"single","resource":"iageneric:item/box","sprite":"minecraft:item/stick"},
+                {"type":"single","resource":"minecraft:item/stick","sprite":"ia:3"},
+                {"type":"single","resource":"iageneric:item/gone","sprite":"ia:2"},
+                {"type":"single","resource":"iageneric:item/box","sprite":"ia:../../../escape"},
+                {"type":"single","resource":"iageneric:item/box","sprite":"ia:7"},
+                {"type":"single","resource":"iageneric:item/box","sprite":"ia:8"},
+                {"type":"single","resource":"iageneric:item/box","sprite":"ia:9"}
+            ]}"#,
+        );
+        // A pack above it: later sources of three of those sprites, a blocks atlas that
+        // disagrees about another, and a filter hiding vanilla's animation of the stick.
+        let higher = base.join("packs/Top");
+        write(
+            higher.join("pack.mcmeta"),
+            br#"{"pack":{"description":"d","pack_format":97},
+                "filter":{"block":[{"path":"textures/item/stick\\.png\\.mcmeta"}]}}"#,
+        );
+        write(
+            higher.join("assets/minecraft/atlases/items.json"),
+            br#"{"sources":[
+                {"type":"single","resource":"minecraft:block/sea_lantern","sprite":"ia:8"},
+                {"type":"filter","pattern":{"namespace":"ia","path":"7"}}
+            ]}"#,
+        );
+        write(
+            higher.join("assets/minecraft/atlases/blocks.json"),
+            br#"{"sources":[
+                {"type":"single","resource":"minecraft:block/sea_lantern","sprite":"ia:9"}
+            ]}"#,
+        );
+        let packs = discover(&vanilla, &base.join("packs"));
+        let out = base.join("overlay");
+        build_overlay(&vanilla, &packs, &out).unwrap();
+        let read = |rel: &str| fs::read(out.join(rel)).ok();
+        let texture = |id: &str| read(&format!("assets/ia/textures/{id}.png"));
+        assert_eq!(texture("0").as_deref(), Some(&b"box"[..]));
+        assert_eq!(read("assets/ia/textures/0.png.mcmeta"), None);
+        // A vanilla resource comes with its animation.
+        assert_eq!(texture("1199").as_deref(), Some(&b"lantern"[..]));
+        assert_eq!(
+            read("assets/ia/textures/1199.png.mcmeta").as_deref(),
+            Some(&animation[..])
+        );
+        // A texture that is there stays itself: other sources may read it (here as `ia:3`'s
+        // resource; an unstitched or paletted sprite's input alike).
+        assert_eq!(
+            read("assets/minecraft/textures/item/stick.png").as_deref(),
+            Some(&b"vanilla stick"[..])
+        );
+        // ...with its `.mcmeta` only where no filter hides it.
+        assert_eq!(texture("3").as_deref(), Some(&b"vanilla stick"[..]));
+        assert_eq!(read("assets/ia/textures/3.png.mcmeta"), None);
+        // A missing resource adds nothing, and no rename leaves the overlay.
+        assert_eq!(texture("2"), None);
+        assert!(!out.join("escape.png").exists());
+        // The last source of a sprite wins: a filter drops it, a later rename replaces it.
+        assert_eq!(texture("7"), None);
+        assert_eq!(texture("8").as_deref(), Some(&b"lantern"[..]));
+        // The two atlases read one file, and disagree about `ia:9`: it gets neither.
+        assert_eq!(texture("9"), None);
+        let _ = fs::remove_dir_all(base);
+    }
+    #[test]
    fn every_file_of_a_big_stack_comes_from_its_top_pack() {
        use std::io::Write as _;
        let base = std::env::temp_dir().join(format!("horizon-pack-stack-{}", std::process::id()));
@@ -13,7 +13,8 @@ use std::{collections::BTreeSet, fs, io, path::Path, path::PathBuf};
 // Version 5 read every vanilla file to stamp it on Windows.
 // Version 6 stamps vanilla's files by their metadata on Windows too.
 // Version 7 stacks blockstate files (every pack's definition, bottom first).
-const VERSION: u32 = 8;
+// Version 8 left an atlas `single` source's renamed sprite without its texture file (#14485).
+const VERSION: u32 = 9;

 #[derive(Default, Serialize, Deserialize)]
 pub(super) struct Dependencies {
@@ -1402,100 +1402,8 @@ impl ParticleLightCache {
    }
 }

-const PARTICLE_SECTION_CACHE_SIZE: usize = 128;
-
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
-enum SectionFrustumResult {
-    Outside,
-    Intersects,
-    Inside,
-}
-
-#[derive(Clone, Copy)]
-struct CachedSectionFrustum {
-    section: [i32; 3],
-    radius_quarters: i32,
-    result: SectionFrustumResult,
-}
-
-struct ParticleSectionFrustumCache {
-    entries: [Option<CachedSectionFrustum>; PARTICLE_SECTION_CACHE_SIZE],
-}
-
-impl Default for ParticleSectionFrustumCache {
-    fn default() -> Self {
-        Self {
-            entries: [None; PARTICLE_SECTION_CACHE_SIZE],
-        }
-    }
-}
-
-impl ParticleSectionFrustumCache {
-    fn result(
-        &mut self,
-        world: [f64; 3],
-        camera: DVec3,
-        radius: f64,
-        frustum: &crate::gfx::Frustum,
-    ) -> SectionFrustumResult {
-        let Some(section) = world_section(world) else {
-            return SectionFrustumResult::Intersects;
-        };
-        if !radius.is_finite() || radius < 0.0 || radius * 4.0 > f64::from(i32::MAX) {
-            return SectionFrustumResult::Intersects;
-        }
-        let radius_quarters = (radius * 4.0).ceil() as i32;
-        let hash = (section[0] as u32).wrapping_mul(73_856_093)
-            ^ (section[1] as u32).wrapping_mul(19_349_663)
-            ^ (section[2] as u32).wrapping_mul(83_492_791)
-            ^ (radius_quarters as u32).wrapping_mul(2_654_435_761);
-        let slot = hash as usize & (PARTICLE_SECTION_CACHE_SIZE - 1);
-        if let Some(entry) = self.entries[slot]
-            && entry.section == section
-            && entry.radius_quarters == radius_quarters
-        {
-            return entry.result;
-        }
-
-        let pad = f64::from(radius_quarters) * 0.25;
-        let camera = camera.to_array();
-        let min = array::from_fn(|axis| f64::from(section[axis]) * 16.0 - pad - camera[axis]);
-        let max = array::from_fn(|axis| min[axis] + 16.0 + 2.0 * pad);
-        let result = if min.into_iter().chain(max).any(|v| !v.is_finite()) {
-            SectionFrustumResult::Intersects
-        } else {
-            let min = FVec3::from_array(min.map(|v| v as f32));
-            let max = FVec3::from_array(max.map(|v| v as f32));
-            if !min.is_finite() || !max.is_finite() {
-                SectionFrustumResult::Intersects
-            } else if frustum.contains(min, max) {
-                SectionFrustumResult::Inside
-            } else if frustum.intersects(min, max) {
-                SectionFrustumResult::Intersects
-            } else {
-                SectionFrustumResult::Outside
-            }
-        };
-        self.entries[slot] = Some(CachedSectionFrustum {
-            section,
-            radius_quarters,
-            result,
-        });
-        result
-    }
-}
-
-fn world_section(position: [f64; 3]) -> Option<[i32; 3]> {
-    let mut block = [0; 3];
-    for axis in 0..3 {
-        let value = position[axis].floor();
-        if !value.is_finite() || value < f64::from(i32::MIN) || value > f64::from(i32::MAX) {
-            return None;
-        }
-        block[axis] = value as i32;
-    }
-    Some([block[0] >> 4, block[1] >> 4, block[2] >> 4])
-}
+mod view_cull;
+use view_cull::{PARTICLE_FRUSTUM_OFFSET, ParticleSectionFrustumCache, SectionFrustumResult};

 fn below_half_pixel(radius: f64, distance_squared: f64, pixel_focal_length: f32) -> bool {
    let projected_limit = 4.0 * radius * f64::from(pixel_focal_length);
@@ -4703,16 +4611,7 @@ impl ParticleEngine {
        light_at: &dyn Fn([i32; 3]) -> u8,
        out: &mut Vec<Vertex>,
    ) {
-        self.render_inner::<false>(
-            camera,
-            base,
-            partial,
-            0.0,
-            None,
-            &mut |_, _| false,
-            light_at,
-            out,
-        );
+        self.render_in_view(camera, base, partial, None, light_at, out);
    }

    /// Render particles after rejecting view-frustum misses and any particles
@@ -4730,7 +4629,7 @@ impl ParticleEngine {
        out: &mut Vec<Vertex>,
    ) {
        if !culling_enabled {
-            self.render(camera, base, partial, light_at, out);
+            self.render_in_view(camera, base, partial, frustum, light_at, out);
            return;
        }
        self.render_inner::<true>(
@@ -4761,10 +4660,16 @@ impl ParticleEngine {
        additive.clear();
        let mut section_cache =
            (CULL && frustum.is_some()).then(ParticleSectionFrustumCache::default);
+        let view = frustum.map(|f| f.pulled_back(PARTICLE_FRUSTUM_OFFSET));
        for p in &self.particles {
            if p.no_render {
                continue;
            }
+            if let Some(view) = &view
+                && !view_cull::in_view(view, p, camera)
+            {
+                continue;
+            }
            // SparkParticle.extract: twinkling sparks blink after a third of their life.
            if let Behaviour::Spark { twinkle: true, .. } = p.behaviour
                && p.age >= p.lifetime / 3
@@ -5199,6 +5104,115 @@ mod tests {
        assert_eq!(attributes(&disabled), attributes(&regular));
    }

+    /// An engine whose smoke particles stand at `positions`, camera-relative (the camera is at
+    /// the origin looking down -z, like `Mat4::IDENTITY` as a view).
+    fn smoke_at(positions: &[[f64; 3]]) -> ParticleEngine {
+        let mut engine = ParticleEngine::new(Path::new(""), &HashMap::new(), &HashSet::new());
+        let sprite = "test:smoke".to_owned();
+        engine.atlas.insert(
+            sprite.clone(),
+            (
+                Rect {
+                    u0: 0.0,
+                    v0: 0.0,
+                    u1: 1.0,
+                    v1: 1.0,
+                    w: 16,
+                    h: 16,
+                },
+                false,
+            ),
+        );
+        let mut random = LegacyRandom::new(7);
+        for &at in positions {
+            let mut particle = Particle::moving(&mut random, ParticleType::Smoke, at, [0.0; 3]);
+            particle.sprite = Sprite::Named(sprite.clone());
+            engine.particles.push(particle);
+        }
+        engine
+    }
+
+    fn quad_vertices(engine: &ParticleEngine, view: Option<&crate::gfx::Frustum>) -> usize {
+        let mut out = Vec::new();
+        engine.render_in_view(DVec3::ZERO, Quat::IDENTITY, 0.5, view, &|_| 0xf0, &mut out);
+        out.len()
+    }
+
+    #[test]
+    fn particles_outside_the_pulled_back_frustum_make_no_quads() {
+        use crate::gfx::{Frustum, world_projection};
+        let view = Frustum::from_view_projection(world_projection(70.0, 16.0 / 9.0, 512.0));
+        let kept = [
+            [0.0, 0.0, -5.0],   // straight ahead
+            [0.0, 0.0, 2.5],    // behind the camera, inside the 3 blocks of offset
+            [0.0, 0.0, -300.0], // far, inside the far plane
+        ];
+        let dropped = [
+            [0.0, 0.0, 10.0],   // well behind the camera
+            [0.0, 0.0, 3.5],    // just past the offset
+            [100.0, 0.0, -5.0], // far to the side
+            [0.0, 60.0, -5.0],  // far above
+            [0.0, 0.0, -600.0], // beyond the far plane
+        ];
+        let all: Vec<_> = kept.iter().chain(&dropped).copied().collect();
+        let engine = smoke_at(&all);
+        let only_kept = quad_vertices(&smoke_at(&kept), None);
+        assert!(only_kept > 0);
+        assert_eq!(quad_vertices(&engine, Some(&view)), only_kept);
+        // Without a view every particle is drawn, as before.
+        assert_eq!(
+            quad_vertices(&engine, None),
+            only_kept * all.len() / kept.len()
+        );
+        // `render` is the same as no view.
+        let mut regular = Vec::new();
+        engine.render(DVec3::ZERO, Quat::IDENTITY, 0.5, &|_| 0xf0, &mut regular);
+        assert_eq!(regular.len(), quad_vertices(&engine, None));
+    }
+
+    #[test]
+    fn the_culled_path_applies_the_same_frustum_test() {
+        use crate::gfx::{Frustum, world_projection};
+        let view = Frustum::from_view_projection(world_projection(70.0, 16.0 / 9.0, 512.0));
+        let engine = smoke_at(&[[0.0, 0.0, -5.0], [0.0, 0.0, 10.0]]);
+        let mut out = Vec::new();
+        // The disabled setting still keeps vanilla's always-on test.
+        engine.render_culled(
+            DVec3::ZERO,
+            Quat::IDENTITY,
+            0.5,
+            900.0,
+            false,
+            Some(&view),
+            |_, _| panic!("disabled culling must not query particle visibility"),
+            &|_| 0xf0,
+            &mut out,
+        );
+        assert_eq!(
+            out.len(),
+            quad_vertices(&smoke_at(&[[0.0, 0.0, -5.0]]), None)
+        );
+    }
+
+    #[test]
+    fn a_particle_is_tested_at_its_position_this_tick_not_an_interpolated_one() {
+        use crate::gfx::{Frustum, world_projection};
+        let view = Frustum::from_view_projection(world_projection(70.0, 16.0 / 9.0, 512.0));
+        // The frame is drawn half way (0.5) between `previous` and `position`.
+        // Ahead now, far behind a tick ago (half way: 12.5 behind, outside): kept.
+        let mut coming = smoke_at(&[[0.0, 0.0, -5.0]]);
+        coming.particles[0].previous = [0.0, 0.0, 30.0];
+        assert!(quad_vertices(&coming, None) > 0);
+        assert_eq!(
+            quad_vertices(&coming, Some(&view)),
+            quad_vertices(&coming, None)
+        );
+        // Behind now, ahead a tick ago (half way: 5 ahead, inside): dropped.
+        let mut going = smoke_at(&[[0.0, 0.0, 10.0]]);
+        going.particles[0].previous = [0.0, 0.0, -20.0];
+        assert_eq!(quad_vertices(&going, Some(&view)), 0);
+    }
+
    #[test]
    fn quads_face_the_rotation_they_are_given() {
        let mut engine = ParticleEngine::new(Path::new(""), &HashMap::new(), &HashSet::new());
@@ -0,0 +1,138 @@
+//! The camera's view frustum for particles: vanilla's always-on point test, and the section
+//! cache behind the opt-in Particle Culling setting.
+
+use super::{Particle, ParticleEngine, Vertex};
+use glam::{DVec3, Quat, Vec3 as FVec3};
+use std::array;
+
+const PARTICLE_SECTION_CACHE_SIZE: usize = 128;
+/// How far back, in blocks, the camera's frustum is pulled for the particle test (vanilla's
+/// `Frustum.offset` in `ParticleEngine.extract`).
+pub(super) const PARTICLE_FRUSTUM_OFFSET: f32 = 3.0;
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub(super) enum SectionFrustumResult {
+    Outside,
+    Intersects,
+    Inside,
+}
+
+#[derive(Clone, Copy)]
+struct CachedSectionFrustum {
+    section: [i32; 3],
+    radius_quarters: i32,
+    result: SectionFrustumResult,
+}
+
+pub(super) struct ParticleSectionFrustumCache {
+    entries: [Option<CachedSectionFrustum>; PARTICLE_SECTION_CACHE_SIZE],
+}
+
+impl Default for ParticleSectionFrustumCache {
+    fn default() -> Self {
+        Self {
+            entries: [None; PARTICLE_SECTION_CACHE_SIZE],
+        }
+    }
+}
+
+impl ParticleSectionFrustumCache {
+    pub(super) fn result(
+        &mut self,
+        world: [f64; 3],
+        camera: DVec3,
+        radius: f64,
+        frustum: &crate::gfx::Frustum,
+    ) -> SectionFrustumResult {
+        let Some(section) = world_section(world) else {
+            return SectionFrustumResult::Intersects;
+        };
+        if !radius.is_finite() || radius < 0.0 || radius * 4.0 > f64::from(i32::MAX) {
+            return SectionFrustumResult::Intersects;
+        }
+        let radius_quarters = (radius * 4.0).ceil() as i32;
+        let hash = (section[0] as u32).wrapping_mul(73_856_093)
+            ^ (section[1] as u32).wrapping_mul(19_349_663)
+            ^ (section[2] as u32).wrapping_mul(83_492_791)
+            ^ (radius_quarters as u32).wrapping_mul(2_654_435_761);
+        let slot = hash as usize & (PARTICLE_SECTION_CACHE_SIZE - 1);
+        if let Some(entry) = self.entries[slot]
+            && entry.section == section
+            && entry.radius_quarters == radius_quarters
+        {
+            return entry.result;
+        }
+
+        let pad = f64::from(radius_quarters) * 0.25;
+        let camera = camera.to_array();
+        let min = array::from_fn(|axis| f64::from(section[axis]) * 16.0 - pad - camera[axis]);
+        let max = array::from_fn(|axis| min[axis] + 16.0 + 2.0 * pad);
+        let result = if min.into_iter().chain(max).any(|v| !v.is_finite()) {
+            SectionFrustumResult::Intersects
+        } else {
+            let min = FVec3::from_array(min.map(|v| v as f32));
+            let max = FVec3::from_array(max.map(|v| v as f32));
+            if !min.is_finite() || !max.is_finite() {
+                SectionFrustumResult::Intersects
+            } else if frustum.contains(min, max) {
+                SectionFrustumResult::Inside
+            } else if frustum.intersects(min, max) {
+                SectionFrustumResult::Intersects
+            } else {
+                SectionFrustumResult::Outside
+            }
+        };
+        self.entries[slot] = Some(CachedSectionFrustum {
+            section,
+            radius_quarters,
+            result,
+        });
+        result
+    }
+}
+
+fn world_section(position: [f64; 3]) -> Option<[i32; 3]> {
+    let mut block = [0; 3];
+    for axis in 0..3 {
+        let value = position[axis].floor();
+        if !value.is_finite() || value < f64::from(i32::MIN) || value > f64::from(i32::MAX) {
+            return None;
+        }
+        block[axis] = value as i32;
+    }
+    Some([block[0] >> 4, block[1] >> 4, block[2] >> 4])
+}
+
+/// Whether `QuadParticleGroup`'s test keeps `particle`: its position this tick (camera-relative, not
+/// interpolated) is on or inside `view`, the camera's frustum pulled back [`PARTICLE_FRUSTUM_OFFSET`] blocks.
+pub(super) fn in_view(view: &crate::gfx::Frustum, particle: &Particle, camera: DVec3) -> bool {
+    let at = DVec3::from_array(particle.position) - camera;
+    view.contains_point(at.as_vec3())
+}
+
+impl ParticleEngine {
+    /// [`Self::render`], keeping only the particles inside `view`, the camera's frustum pulled
+    /// back [`PARTICLE_FRUSTUM_OFFSET`] blocks (vanilla's `ParticleEngine.extract` and
+    /// `QuadParticleGroup`): the test runs whatever the Particle Culling setting says. With
+    /// `None`, every particle is drawn.
+    pub fn render_in_view(
+        &self,
+        camera: DVec3,
+        base: Quat,
+        partial: f32,
+        view: Option<&crate::gfx::Frustum>,
+        light_at: &dyn Fn([i32; 3]) -> u8,
+        out: &mut Vec<Vertex>,
+    ) {
+        self.render_inner::<false>(
+            camera,
+            base,
+            partial,
+            0.0,
+            view,
+            &mut |_, _| false,
+            light_at,
+            out,
+        );
+    }
+}
@@ -0,0 +1,406 @@
+//! A stopped sampler session as the capture's `samples` message (docs/perf-platform.md §3.5).
+use std::collections::HashMap;
+
+use horizon_perf_format::Interner;
+use horizon_perf_format::v1::{
+    BlockUnits, Contexts, Functions, Nodes, Overhead, SampleKind, SampleProfile, SampleSource,
+    SampleUnit, SampledThread, Side, Unit, Weights,
+};
+use horizon_threads::heap_sample::HeapProfile;
+use horizon_threads::profile::{Aggregate, Frame, Profile, State, Symbols, symbolize};
+use horizon_threads::work::{self, Space};
+
+#[cfg(test)]
+mod tests;
+
+const UNKNOWN: &str = "[unknown]";
+
+/// The name `work::set_dim` ids stand for: 1 overworld, 2 the nether, 3 the end.
+fn dimension_name(id: u8) -> Option<&'static str> {
+    match id {
+        1 => Some("overworld"),
+        2 => Some("the_nether"),
+        3 => Some("the_end"),
+        _ => None,
+    }
+}
+
+/// The crate a demangled function name belongs to, or "" when it names none.
+fn crate_of(name: &str) -> &str {
+    if let Some(inner) = name.strip_prefix('[') {
+        let module = inner.split([' ', ']']).next().unwrap_or("");
+        return if module == "unmapped" { "" } else { module };
+    }
+    let name = name.trim_start_matches(['<', '&', '*']);
+    let name = name.strip_prefix("dyn ").unwrap_or(name);
+    match name.split_once("::") {
+        Some((krate, _)) if krate.chars().all(|c| c.is_alphanumeric() || c == '_') => krate,
+        _ => "",
+    }
+}
+
+#[derive(Default)]
+struct FunctionTable {
+    rows: Functions,
+    index: HashMap<(u32, u32), u32>,
+    allocator: Vec<bool>,
+}
+
+impl FunctionTable {
+    fn id(
+        &mut self,
+        strings: &mut Interner,
+        name: &str,
+        file: Option<&str>,
+        line: u32,
+        addr: u64,
+    ) -> u32 {
+        let (name_id, file_id) = (
+            strings.intern(name),
+            file.map_or(0, |file| strings.intern(file)),
+        );
+        if let Some(&row) = self.index.get(&(name_id, file_id)) {
+            return row;
+        }
+        let row = self.rows.name.len() as u32;
+        self.rows.name.push(name_id);
+        self.rows.file.push(file_id);
+        self.rows.line.push(line);
+        self.rows.crate_.push(match crate_of(name) {
+            "" => 0,
+            krate => strings.intern(krate),
+        });
+        self.rows.addr.push(addr);
+        self.allocator.push(allocator_frame(name));
+        self.index.insert((name_id, file_id), row);
+        row
+    }
+}
+
+/// The thread each trie node belongs to; node 0 is the root.
+fn thread_of(agg: &Aggregate) -> Vec<u16> {
+    let mut of = vec![0u16; agg.nodes()];
+    for n in 1..agg.nodes() {
+        of[n] = match agg.frame(n as u32) {
+            Frame::Thread(i) => i,
+            _ => of[agg.parent(n as u32) as usize],
+        };
+    }
+    of
+}
+
+/// The trie nodes some counted sample passes through.
+fn live_nodes(agg: &Aggregate) -> Vec<bool> {
+    let mut live = vec![false; agg.nodes()];
+    for key in agg.counts.keys() {
+        let mut n = key.node as usize;
+        while n != 0 && !live[n] {
+            live[n] = true;
+            n = agg.parent(n as u32) as usize;
+        }
+    }
+    live
+}
+
+#[derive(Default)]
+struct NodeTable {
+    rows: Nodes,
+    index: HashMap<(Option<u32>, u32, u16), u32>,
+}
+
+impl NodeTable {
+    fn id(&mut self, parent: Option<u32>, function: u32, thread: u16) -> u32 {
+        let key = (parent, function, if parent.is_none() { thread } else { 0 });
+        if let Some(&row) = self.index.get(&key) {
+            return row;
+        }
+        let nodes = &mut self.rows;
+        nodes.parent.push(parent.unwrap_or(0));
+        nodes.function.push(function);
+        nodes.thread_root.push(match parent {
+            None => u32::from(thread) + 1,
+            Some(_) => 0,
+        });
+        let row = nodes.parent.len() as u32 - 1;
+        self.index.insert(key, row);
+        row
+    }
+}
+
+fn named(strings: &mut Interner, space: Space, id: u16) -> u32 {
+    match id {
+        0 => 0,
+        id => match work::name(space, id) {
+            Some(name) => strings.intern(name),
+            None => strings.intern(&format!("#{id}")),
+        },
+    }
+}
+
+/// Whether `name` is the allocator's own frame, which a heap sample's stack drops from its leaf end.
+fn allocator_frame(name: &str) -> bool {
+    let name = name.trim_start_matches('<');
+    name.starts_with("horizon_threads::heap_sample::")
+        || name.starts_with("__rust")
+        || name.starts_with("__rg_")
+        || name.starts_with("__rdl_")
+        || name.starts_with("alloc::alloc::")
+        || name.starts_with("alloc::raw_vec::")
+        || name.starts_with("mimalloc::")
+}
+
+/// One aggregate's trie nodes as rows of the shared tables: `last[n]` is the output node of trie node `n`.
+fn add_tree(
+    agg: &Aggregate,
+    threads: &[u16],
+    symbols: &Symbols,
+    functions: &mut FunctionTable,
+    nodes: &mut NodeTable,
+    strings: &mut Interner,
+) -> (Vec<u16>, Vec<Option<u32>>) {
+    let (local, live) = (thread_of(agg), live_nodes(agg));
+    let thread_of: Vec<u16> = local
+        .iter()
+        .map(|&t| threads.get(usize::from(t)).copied().unwrap_or(0))
+        .collect();
+    let mut last: Vec<Option<u32>> = vec![None; agg.nodes()];
+    for n in (1..agg.nodes()).filter(|&n| live[n]) {
+        let inherited = last[agg.parent(n as u32) as usize];
+        last[n] = match agg.frame(n as u32) {
+            Frame::Thread(_) => None,
+            Frame::Wall(_) => inherited,
+            Frame::Addr(addr) => {
+                let offset = symbols.module_offset(addr);
+                let mut at = inherited;
+                for sym in symbols.frames(addr).iter().rev() {
+                    let f = functions.id(strings, &sym.name, sym.file.as_deref(), sym.line, offset);
+                    at = Some(nodes.id(at, f, thread_of[n]));
+                }
+                if at == inherited {
+                    let f = functions.id(strings, UNKNOWN, None, 0, offset);
+                    at = Some(nodes.id(at, f, thread_of[n]));
+                }
+                at
+            }
+        };
+    }
+    (thread_of, last)
+}
+
+fn trie_addrs(agg: &Aggregate) -> impl Iterator<Item = u64> + '_ {
+    let live = live_nodes(agg);
+    (1..agg.nodes())
+        .filter(move |&n| live[n])
+        .filter_map(|n| match agg.frame(n as u32) {
+            Frame::Addr(a) => Some(a),
+            _ => None,
+        })
+}
+
+/// `profile` (and the heap session's `heap`) as a `SampleProfile` of `side`; strings go through `strings`, whose new entries the caller appends first.
+pub fn sample_profile(
+    profile: &Profile,
+    heap: Option<&HeapProfile>,
+    side: Side,
+    unit: Unit,
+    block_name: &dyn Fn(u16) -> Option<String>,
+    strings: &mut Interner,
+) -> SampleProfile {
+    let agg = &profile.agg;
+    let addrs: Vec<u64> = trie_addrs(agg)
+        .chain(heap.into_iter().flat_map(|h| trie_addrs(&h.agg)))
+        .collect();
+    let symbols = symbolize(addrs);
+
+    let mut names: Vec<String> = agg.threads.clone();
+    let cpu_threads: Vec<u16> = (0..agg.threads.len() as u16).collect();
+    let heap_threads: Vec<u16> = heap.map_or_else(Vec::new, |h| {
+        h.agg
+            .threads
+            .iter()
+            .map(|name| match names.iter().position(|n| n == name) {
+                Some(at) => at as u16,
+                None => {
+                    names.push(name.clone());
+                    names.len() as u16 - 1
+                }
+            })
+            .collect()
+    });
+
+    let mut functions = FunctionTable::default();
+    let mut nodes = NodeTable::default();
+    let mut trees = vec![(
+        agg,
+        add_tree(
+            agg,
+            &cpu_threads,
+            &symbols,
+            &mut functions,
+            &mut nodes,
+            strings,
+        ),
+    )];
+    if let Some(h) = heap {
+        let tree = add_tree(
+            &h.agg,
+            &heap_threads,
+            &symbols,
+            &mut functions,
+            &mut nodes,
+            strings,
+        );
+        trees.push((&h.agg, tree));
+    }
+
+    let wall = agg.counts.keys().any(|k| k.state != State::Cpu);
+    let period_ms = 1000.0 / f64::from(profile.config.sampler.hz.max(1));
+    let kind = |source: SampleSource, unit: SampleUnit, period: f64| SampleKind {
+        source: source as i32,
+        unit: unit as i32,
+        period,
+    };
+    let mut kinds = vec![kind(SampleSource::Cpu, SampleUnit::Ms, period_ms)];
+    if wall {
+        kinds.push(kind(SampleSource::Wall, SampleUnit::Ms, period_ms));
+    }
+    if heap.is_some() {
+        kinds.push(kind(SampleSource::Alloc, SampleUnit::Bytes, 1.0));
+        kinds.push(kind(SampleSource::Live, SampleUnit::Bytes, 1.0));
+    }
+    let kind_of = |state: State| -> u32 {
+        let source = match state {
+            State::Cpu => SampleSource::Cpu,
+            State::Running | State::Waiting => SampleSource::Wall,
+            State::Alloc => SampleSource::Alloc,
+            State::Live => SampleSource::Live,
+        };
+        kinds
+            .iter()
+            .position(|k| k.source == source as i32)
+            .unwrap_or(0) as u32
+    };
+
+    let mut contexts = Contexts::default();
+    let mut context_ids: HashMap<[u32; 6], u32> = HashMap::new();
+    let mut weights = Weights::default();
+    let mut unknown_roots: HashMap<u16, u32> = HashMap::new();
+    for (agg, (thread_of, last)) in &trees {
+        let mut counted: Vec<_> = agg.counts.iter().collect();
+        counted.sort_by_key(|(k, _)| {
+            (
+                thread_of[k.node as usize],
+                k.node,
+                k.state as u8,
+                k.slow,
+                k.time_block,
+                (k.span, k.entity, k.block, k.dim, k.chunk),
+            )
+        });
+        for (key, &count) in counted {
+            let thread = thread_of[key.node as usize];
+            let mut node = match last[key.node as usize] {
+                Some(node) => node,
+                None => *unknown_roots.entry(thread).or_insert_with(|| {
+                    let f = functions.id(strings, UNKNOWN, None, 0, 0);
+                    nodes.id(None, f, thread)
+                }),
+            };
+            if matches!(key.state, State::Alloc | State::Live) {
+                while nodes.rows.thread_root[node as usize] == 0
+                    && functions.allocator[nodes.rows.function[node as usize] as usize]
+                {
+                    node = nodes.rows.parent[node as usize];
+                }
+            }
+            let row = [
+                named(strings, Space::Span, key.span),
+                named(strings, Space::Entity, key.entity),
+                match key.block {
+                    0 => 0,
+                    id => match block_name(id) {
+                        Some(name) => strings.intern(&name),
+                        None => strings.intern(&format!("#{id}")),
+                    },
+                },
+                dimension_name(key.dim).map_or(0, |name| strings.intern(name)),
+                key.chunk.0 as u32,
+                key.chunk.1 as u32,
+            ];
+            let context = *context_ids.entry(row).or_insert_with(|| {
+                contexts.span.push(row[0]);
+                contexts.entity.push(row[1]);
+                contexts.block.push(row[2]);
+                contexts.dim.push(row[3]);
+                contexts.chunk_x.push(key.chunk.0);
+                contexts.chunk_z.push(key.chunk.1);
+                contexts.span.len() as u32 - 1
+            });
+            weights.node.push(node);
+            weights.thread.push(u32::from(thread));
+            weights.kind.push(kind_of(key.state));
+            weights.state.push(match key.state {
+                State::Running => 1,
+                State::Waiting => 2,
+                State::Cpu | State::Alloc | State::Live => 0,
+            });
+            weights.slow.push(key.slow);
+            weights.context.push(context);
+            weights.block.push(u32::from(key.time_block));
+            weights.count.push(count);
+        }
+    }
+
+    let blocks = agg.time_blocks();
+    let mut threads = Vec::new();
+    let mut block_units = Vec::new();
+    for (i, name) in names.iter().enumerate() {
+        let ticks = agg.ticks.get(&(i as u16)).filter(|_| i < agg.threads.len());
+        threads.push(SampledThread {
+            name: strings.intern(name),
+            units: ticks.map_or(0, |t| t.count),
+            slow_units: ticks.map_or(0, |t| t.slow),
+            unit: unit as i32,
+        });
+        if i >= agg.threads.len() {
+            continue;
+        }
+        let mut units = agg
+            .block_ticks
+            .get(&(i as u16))
+            .cloned()
+            .unwrap_or_default();
+        units.resize(blocks, 0);
+        block_units.push(BlockUnits {
+            thread: i as u32,
+            units,
+        });
+    }
+
+    SampleProfile {
+        side: side as i32,
+        kinds,
+        threads,
+        block_s: profile.config.block_s,
+        block_units,
+        functions: Some(functions.rows),
+        nodes: Some(nodes.rows),
+        contexts: Some(contexts),
+        weights: Some(weights),
+        slow_over_ms: profile.config.ticks_over_ms as f32,
+    }
+}
+
+/// What the sampler and its writer thread cost during the session.
+pub fn overhead(profile: &Profile, heap: Option<&HeapProfile>) -> Overhead {
+    let wall_ns = profile.elapsed.as_nanos().max(1) as f64;
+    let handler_ns = profile.stats.handler_ns.unwrap_or(0.0) * profile.stats.samples as f64;
+    Overhead {
+        sampler_share_of_thread: (handler_ns / wall_ns) as f32,
+        writer_core_share: (profile.writer_cpu_ns as f64 / wall_ns) as f32,
+        dropped_samples: profile.stats.dropped + profile.agg.lost + heap.map_or(0, |h| h.agg.lost),
+        heap_samples: heap.map_or(0, |h| h.samples),
+        heap_sample_ns: heap.map_or(0, |h| h.sample_ns),
+        ..Overhead::default()
+    }
+}
@@ -0,0 +1,649 @@
+use std::collections::HashMap;
+use std::hint::black_box;
+use std::sync::mpsc;
+use std::thread;
+use std::time::{Duration, SystemTime};
+
+use horizon_perf_format::v1::{
+    Kind as CaptureKind, SampleProfile, Side, Start, Stop, StringEntry, Unit,
+};
+use horizon_perf_format::{CaptureWriter, Field};
+use horizon_threads::profile::{self, Aggregate, Config, Profile};
+use horizon_threads::sampler::{self, Context, Kind, Record, Stats};
+use horizon_threads::unwind::MAX_FRAMES;
+use horizon_threads::work;
+
+use super::*;
+
+#[inline(never)]
+fn alpha() {
+    black_box(1);
+}
+
+#[inline(never)]
+fn beta() {
+    black_box(2);
+}
+
+#[inline(never)]
+fn gamma() {
+    black_box(3);
+}
+
+fn at(f: fn(), offset: usize) -> usize {
+    f as *const () as usize + offset
+}
+
+fn record(kind: Kind, ctx: Context, value: u64, stack: &[usize]) -> Record {
+    let mut frames = [0; MAX_FRAMES];
+    frames[..stack.len()].copy_from_slice(stack);
+    Record {
+        kind,
+        depth: stack.len() as u8,
+        ctx,
+        value,
+        frames,
+    }
+}
+
+fn profile_of(agg: Aggregate, config: Config) -> Profile {
+    Profile {
+        agg,
+        config,
+        stats: Stats::default(),
+        elapsed: Duration::from_secs(10),
+        started: SystemTime::now(),
+        writer_cpu_ns: 0,
+    }
+}
+
+struct Converted {
+    samples: SampleProfile,
+    strings: Vec<StringEntry>,
+}
+
+impl Converted {
+    fn text(&self, id: u32) -> &str {
+        match id {
+            0 => "",
+            id => &self.strings.iter().find(|s| s.id == id).unwrap().text,
+        }
+    }
+
+    fn function(&self, row: u32) -> &str {
+        self.text(self.samples.functions.as_ref().unwrap().name[row as usize])
+    }
+
+    /// Function names from the root down to `node`.
+    fn path(&self, node: u32) -> Vec<&str> {
+        let nodes = self.samples.nodes.as_ref().unwrap();
+        let mut path = vec![self.function(nodes.function[node as usize])];
+        let mut at = node as usize;
+        while nodes.thread_root[at] == 0 {
+            at = nodes.parent[at] as usize;
+            path.push(self.function(nodes.function[at]));
+        }
+        path.reverse();
+        path
+    }
+
+    /// Samples per entity name, optionally only the slow ones.
+    fn by_entity(&self, slow_only: bool) -> HashMap<String, u64> {
+        let (w, c) = (
+            self.samples.weights.as_ref().unwrap(),
+            self.samples.contexts.as_ref().unwrap(),
+        );
+        let mut by = HashMap::new();
+        for i in 0..w.node.len() {
+            if slow_only && !w.slow[i] {
+                continue;
+            }
+            let entity = self.text(c.entity[w.context[i] as usize]).to_owned();
+            *by.entry(entity).or_default() += w.count[i];
+        }
+        by
+    }
+}
+
+fn convert(profile: &Profile) -> Converted {
+    let mut interner = Interner::default();
+    let samples = sample_profile(
+        profile,
+        None,
+        Side::Server,
+        Unit::Tick,
+        &|id| (id == 7).then(|| "minecraft:hopper".to_owned()),
+        &mut interner,
+    );
+    Converted {
+        samples,
+        strings: interner.take_new(Side::Server),
+    }
+}
+
+fn short(name: &str) -> &str {
+    name.rsplit("::").next().unwrap()
+}
+
+#[test]
+fn a_stack_becomes_a_root_to_leaf_chain_with_its_context() {
+    let entity = work::entity_id("test:zombie");
+    let ctx = Context {
+        tick: 1,
+        entity_type: entity,
+        block: 7,
+        dim: 2,
+        chunk: (-3, 9),
+        ..Context::default()
+    };
+    let mut agg = Aggregate::new(50_000_000);
+    for _ in 0..5 {
+        agg.add(
+            "tick",
+            &record(Kind::Cpu, ctx, 0, &[at(alpha, 4), at(gamma, 3)]),
+        );
+    }
+    agg.add("tick", &record(Kind::Tick, ctx, 9_000_000, &[]));
+    agg.finish();
+    let c = convert(&profile_of(agg, Config::default()));
+    let w = c.samples.weights.as_ref().unwrap();
+    assert_eq!(
+        (w.node.len(), w.count[0], w.state[0], w.slow[0]),
+        (1, 5, 0, false)
+    );
+    let path: Vec<_> = c.path(w.node[0]).into_iter().map(short).collect();
+    assert_eq!(path, ["gamma", "alpha"]);
+    let nodes = c.samples.nodes.as_ref().unwrap();
+    assert_eq!(nodes.thread_root, [1, 0]);
+    let ctxs = c.samples.contexts.as_ref().unwrap();
+    let row = w.context[0] as usize;
+    assert_eq!(c.text(ctxs.entity[row]), "test:zombie");
+    assert_eq!(c.text(ctxs.block[row]), "minecraft:hopper");
+    assert_eq!(c.text(ctxs.dim[row]), "the_nether");
+    assert_eq!((ctxs.chunk_x[row], ctxs.chunk_z[row]), (-3, 9));
+    assert_eq!(c.text(c.samples.threads[0].name), "tick");
+    assert_eq!(
+        (c.samples.threads[0].units, c.samples.threads[0].slow_units),
+        (1, 0)
+    );
+}
+
+#[test]
+fn addresses_of_one_function_share_one_row() {
+    let ctx = Context::default();
+    let mut agg = Aggregate::new(50_000_000);
+    for (inner, count) in [(4, 2), (8, 3)] {
+        for _ in 0..count {
+            agg.add(
+                "tick",
+                &record(Kind::Cpu, ctx, 0, &[at(alpha, inner), at(gamma, 3)]),
+            );
+        }
+    }
+    agg.add(
+        "tick",
+        &record(Kind::Cpu, ctx, 0, &[at(beta, 4), at(gamma, 3)]),
+    );
+    agg.finish();
+    let c = convert(&profile_of(agg, Config::default()));
+    let f = c.samples.functions.as_ref().unwrap();
+    let names: Vec<_> = (0..f.name.len() as u32)
+        .map(|row| short(c.function(row)))
+        .collect();
+    let mut sorted = names.clone();
+    sorted.sort_unstable();
+    assert_eq!(sorted, ["alpha", "beta", "gamma"]);
+    let w = c.samples.weights.as_ref().unwrap();
+    let on_alpha: u64 = (0..w.node.len())
+        .filter(|&i| short(c.path(w.node[i]).last().unwrap()) == "alpha")
+        .map(|i| w.count[i])
+        .sum();
+    assert_eq!(on_alpha, 5);
+    let n = c.samples.nodes.as_ref().unwrap();
+    let alphas: Vec<usize> = (0..n.function.len())
+        .filter(|&i| short(c.function(n.function[i])) == "alpha")
+        .collect();
+    assert_eq!(alphas.len(), 1, "one node per (parent, function)");
+    assert_eq!(
+        short(c.function(n.function[n.parent[alphas[0]] as usize])),
+        "gamma"
+    );
+    let weight_on_alpha: u64 = (0..w.node.len())
+        .filter(|&i| w.node[i] as usize == alphas[0])
+        .map(|i| w.count[i])
+        .sum();
+    assert_eq!(weight_on_alpha, 5);
+    let alpha_row = names.iter().position(|n| *n == "alpha").unwrap();
+    assert!(f.addr[alpha_row] > 0, "a module-relative address is kept");
+}
+
+#[test]
+fn time_blocks_and_ticks_per_block_follow_when_they_were_added() {
+    let ctx = |tick| Context {
+        tick,
+        ..Context::default()
+    };
+    let mut agg = Aggregate::new(50_000_000);
+    for (block, tick, samples) in [(0, 1, 2u64), (1, 2, 3), (1, 3, 1), (3, 4, 4)] {
+        agg.set_time_block(block);
+        for _ in 0..samples {
+            agg.add("tick", &record(Kind::Cpu, ctx(tick), 0, &[at(alpha, 1)]));
+        }
+        agg.add("tick", &record(Kind::Tick, ctx(tick), 1_000_000, &[]));
+    }
+    agg.finish();
+    let config = Config {
+        block_s: 2.5,
+        ..Config::default()
+    };
+    let c = convert(&profile_of(agg, config));
+    let w = c.samples.weights.as_ref().unwrap();
+    let mut per_block = [0u64; 4];
+    for i in 0..w.node.len() {
+        per_block[w.block[i] as usize] += w.count[i];
+    }
+    assert_eq!(per_block, [2, 4, 0, 4]);
+    assert_eq!(c.samples.block_s, 2.5);
+    assert_eq!(c.samples.block_units[0].units, [1, 2, 0, 1]);
+    assert_eq!(c.samples.threads[0].units, 4);
+}
+
+#[test]
+fn a_sample_with_no_stack_hangs_off_an_unknown_root() {
+    let mut agg = Aggregate::new(50_000_000);
+    agg.add("tick", &record(Kind::Cpu, Context::default(), 0, &[]));
+    agg.finish();
+    let c = convert(&profile_of(agg, Config::default()));
+    let w = c.samples.weights.as_ref().unwrap();
+    assert_eq!(c.path(w.node[0]), ["[unknown]"]);
+}
+
+#[test]
+fn wall_samples_carry_their_state_and_a_second_kind() {
+    let mut agg = Aggregate::new(50_000_000);
+    let ctx = Context::default();
+    agg.add("tick", &record(Kind::Cpu, ctx, 0, &[at(alpha, 1)]));
+    agg.add("tick", &record(Kind::Wall, ctx, 1, &[at(alpha, 1)]));
+    agg.add("tick", &record(Kind::Wall, ctx, 0, &[at(beta, 1)]));
+    agg.finish();
+    let config = Config {
+        sampler: sampler::Config {
+            hz: 200,
+            ..sampler::Config::default()
+        },
+        ..Config::default()
+    };
+    let c = convert(&profile_of(agg, config));
+    assert_eq!(c.samples.kinds.len(), 2);
+    assert_eq!(c.samples.kinds[0].period, 5.0);
+    let w = c.samples.weights.as_ref().unwrap();
+    let mut seen: Vec<_> = (0..w.node.len())
+        .map(|i| {
+            (
+                short(c.path(w.node[i]).last().unwrap()).to_owned(),
+                w.kind[i],
+                w.state[i],
+            )
+        })
+        .collect();
+    seen.sort();
+    assert_eq!(
+        seen,
+        [
+            ("alpha".into(), 0, 0),
+            ("alpha".into(), 1, 1),
+            ("beta".into(), 1, 2)
+        ]
+    );
+}
+
+#[inline(never)]
+fn spin_fast() {
+    spin(8);
+    black_box(0);
+}
+
+#[inline(never)]
+fn spin_slow() {
+    spin(120);
+    black_box(1);
+}
+
+fn spin(cpu_ms: u64) {
+    let until = sampler::thread_cpu_ns() + cpu_ms * 1_000_000;
+    let mut x = 1u64;
+    while sampler::thread_cpu_ns() < until {
+        for _ in 0..1 << 14 {
+            x = black_box(x.wrapping_mul(6364136223846793005).wrapping_add(1));
+        }
+    }
+    black_box(x);
+}
+
+fn live_config() -> Config {
+    Config {
+        sampler: sampler::Config {
+            hz: 1000,
+            ring_samples: 512,
+            unwind: sampler::Unwind::StackCopy,
+            stack_copy_kib: 16,
+            wall: false,
+        },
+        ticks_over_ms: 50.0,
+        ..Config::default()
+    }
+}
+
+/// Runs `body` on a thread opted in as `name`, profiled for exactly its duration.
+fn profiled(name: &'static str, body: fn()) -> Profile {
+    let (ready, wait) = mpsc::channel();
+    let (go, start) = mpsc::channel::<()>();
+    let worker = thread::spawn(move || {
+        assert!(sampler::sampled_thread(name));
+        ready.send(()).unwrap();
+        start.recv().unwrap();
+        body();
+    });
+    wait.recv().unwrap();
+    let session = profile::start(Config {
+        threads: vec![name.into()],
+        ..live_config()
+    })
+    .expect("start profiling");
+    go.send(()).unwrap();
+    worker.join().unwrap();
+    session.stop().expect("stop profiling")
+}
+
+fn entity_units() {
+    let (a, b) = (work::entity_id("test:a"), work::entity_id("test:b"));
+    for unit in 0..4 {
+        work::tick_start();
+        work::set_entity(if unit < 3 { a } else { b });
+        let started = sampler::thread_cpu_ns();
+        spin(40);
+        work::clear_work();
+        work::tick_end(sampler::thread_cpu_ns() - started);
+    }
+}
+
+#[test]
+fn three_units_of_a_and_one_of_b_split_the_samples_three_to_one() {
+    let c = convert(&profiled("perf-capture-entities", entity_units));
+    let by = c.by_entity(false);
+    let total = (by["test:a"] + by["test:b"]) as f64;
+    let (a, b) = (by["test:a"] as f64 / total, by["test:b"] as f64 / total);
+    assert!((a - 0.75).abs() < 0.1 && (b - 0.25).abs() < 0.1, "{by:?}");
+    assert!(total > 100.0, "{total} samples");
+    assert_eq!(c.samples.threads[0].units, 4);
+}
+
+fn ticks_with_one_slow() {
+    for tick in 0..6 {
+        work::tick_start();
+        let started = sampler::thread_cpu_ns();
+        if tick == 3 {
+            spin_slow();
+        } else {
+            spin_fast();
+        }
+        work::tick_end(sampler::thread_cpu_ns() - started);
+    }
+}
+
+#[test]
+fn only_the_slow_ticks_function_is_in_the_slow_weights() {
+    let c = convert(&profiled("perf-capture-slow", ticks_with_one_slow));
+    let w = c.samples.weights.as_ref().unwrap();
+    let (mut slow, mut fast) = (0, 0);
+    for i in 0..w.node.len() {
+        let names: Vec<_> = c.path(w.node[i]).into_iter().map(short).collect();
+        if w.slow[i] {
+            slow += w.count[i];
+            assert!(
+                names.contains(&"spin_slow") && !names.contains(&"spin_fast"),
+                "{names:?}"
+            );
+        } else {
+            fast += w.count[i];
+            assert!(!names.contains(&"spin_slow"), "{names:?}");
+        }
+    }
+    assert!(slow > 60 && fast > 20, "{slow} slow, {fast} other");
+    assert_eq!(
+        (c.samples.threads[0].units, c.samples.threads[0].slow_units),
+        (6, 1)
+    );
+}
+
+#[test]
+fn overhead_counts_lost_samples_and_the_writers_share_of_a_core() {
+    let mut agg = Aggregate::new(1);
+    agg.lost = 4;
+    let mut profile = profile_of(agg, Config::default());
+    profile.stats.dropped = 3;
+    profile.stats.samples = 1000;
+    profile.stats.handler_ns = Some(2_000.0);
+    profile.writer_cpu_ns = 50_000_000;
+    let o = overhead(&profile, None);
+    assert_eq!(o.dropped_samples, 7);
+    assert!((o.sampler_share_of_thread - 0.0002).abs() < 1e-7);
+    assert!((o.writer_core_share - 0.005).abs() < 1e-6);
+}
+
+#[test]
+fn crates_come_from_the_first_path_segment() {
+    for (name, krate) in [
+        (
+            "horizon_world::level::tick::random_tick_at",
+            "horizon_world",
+        ),
+        (
+            "<horizon_world::X as core::ops::Drop>::drop",
+            "horizon_world",
+        ),
+        ("core::ptr::drop_in_place<alloc::vec::Vec<u8>>", "core"),
+        ("clone3", ""),
+        ("[horizon-server 0x4f2a]", "horizon-server"),
+        ("[unmapped 0x7ffd]", ""),
+    ] {
+        assert_eq!(crate_of(name), krate, "{name}");
+    }
+}
+
+fn ask(
+    file: &std::path::Path,
+    parts: &[&str],
+) -> horizon_perf::wire::Envelope<horizon_perf::query::Row> {
+    let env = horizon_perf::cli::Env {
+        horizon_home: None,
+        poll: Duration::from_millis(2),
+    };
+    let mut args = vec!["query".to_owned()];
+    args.extend(parts.iter().map(|p| (*p).to_owned()));
+    args.push(file.to_string_lossy().into_owned());
+    let mut out = Vec::new();
+    if let Err(e) = horizon_perf::cli::run(&args, &env, &mut out) {
+        panic!("{e:?}");
+    }
+    serde_json::from_slice(&out)
+        .unwrap_or_else(|e| panic!("{e}: {}", String::from_utf8_lossy(&out)))
+}
+
+#[test]
+fn a_converted_profile_written_to_a_file_reads_back_through_the_queries() {
+    let ctx = Context::default();
+    let mut agg = Aggregate::new(50_000_000);
+    for _ in 0..5 {
+        agg.add(
+            "tick",
+            &record(Kind::Cpu, ctx, 0, &[at(alpha, 4), at(gamma, 3)]),
+        );
+    }
+    for _ in 0..2 {
+        agg.add(
+            "tick",
+            &record(Kind::Cpu, ctx, 0, &[at(beta, 4), at(gamma, 3)]),
+        );
+    }
+    for _ in 0..2 {
+        agg.add("tick", &record(Kind::Tick, ctx, 9_000_000, &[]));
+    }
+    for _ in 0..3 {
+        agg.add("worker", &record(Kind::Cpu, ctx, 0, &[at(beta, 4)]));
+    }
+    agg.add("worker", &record(Kind::Tick, ctx, 9_000_000, &[]));
+    agg.finish();
+    let config = Config {
+        sampler: sampler::Config {
+            hz: 100,
+            ..sampler::Config::default()
+        },
+        ..Config::default()
+    };
+    let c = convert(&profile_of(agg, config));
+    let mut fields = vec![Field::Start(Start {
+        side: Side::Server as i32,
+        kind: CaptureKind::Dedicated as i32,
+        ..Default::default()
+    })];
+    fields.extend(c.strings.into_iter().map(Field::String));
+    fields.push(Field::Samples(c.samples));
+    fields.push(Field::Stop(Stop {
+        side: Side::Server as i32,
+        t: 10.0,
+        ..Default::default()
+    }));
+    let dir = std::env::temp_dir().join(format!("horizon-render-perf-{}", std::process::id()));
+    std::fs::create_dir_all(&dir).unwrap();
+    let file = dir.join("real.hzperf");
+    let mut writer = CaptureWriter::new(std::fs::File::create(&file).unwrap()).unwrap();
+    for field in fields {
+        writer.write(field).unwrap();
+    }
+    writer.finish().unwrap();
+
+    // 10 ms samples: alpha has 5 over the tick thread's 2 ticks.
+    let hot = ask(&file, &["hot"]);
+    let alpha = hot.rows().iter().find_map(|r| match r {
+        horizon_perf::query::Row::Hot(h) if h.full.ends_with("alpha") => Some(h),
+        _ => None,
+    });
+    assert_eq!(alpha.map(|h| (h.self_ms, h.samples)), Some((25.0, 5)));
+    let worker = ask(&file, &["split", "t:worker", "--by", "thread"]);
+    let sel = worker.selection.as_ref().unwrap();
+    assert_eq!(
+        (sel.thread.as_deref(), sel.ticks, sel.samples),
+        (Some("worker"), Some(1), Some(3))
+    );
+    let values: Vec<_> = worker
+        .rows()
+        .iter()
+        .map(|r| match r {
+            horizon_perf::query::Row::Split(s) => (s.key.clone(), s.value),
+            other => panic!("{other:?}"),
+        })
+        .collect();
+    assert_eq!(values, [(Some("t:worker".to_owned()), 30.0)]);
+    std::fs::remove_dir_all(&dir).unwrap();
+}
+
+#[test]
+fn heap_samples_share_the_tables_without_the_allocators_own_frames() {
+    let mut cpu = Aggregate::new(50_000_000);
+    cpu.add(
+        "tick",
+        &record(
+            Kind::Cpu,
+            Context::default(),
+            0,
+            &[at(alpha, 4), at(gamma, 3)],
+        ),
+    );
+    cpu.finish();
+    let mut heap = Aggregate::new(0);
+    let inside = HeapProfile::bytes as *const () as usize + 4;
+    let on_tick = heap.thread_index("tick");
+    let key = heap.stack_key(
+        on_tick,
+        profile::State::Alloc,
+        &Context::default(),
+        &[inside, at(beta, 4), at(gamma, 3)],
+    );
+    heap.add_weight(key, 3000);
+    heap.add_weight(
+        profile::Key {
+            state: profile::State::Live,
+            ..key
+        },
+        1000,
+    );
+    let on_worker = heap.thread_index("worker");
+    let key = heap.stack_key(
+        on_worker,
+        profile::State::Live,
+        &Context::default(),
+        &[inside, at(alpha, 4)],
+    );
+    heap.add_weight(key, 500);
+    let heap = HeapProfile {
+        agg: heap,
+        interval: 4096,
+        samples: 3,
+        live_samples: 2,
+        sample_ns: 0,
+        freed: 2000,
+        elapsed: Duration::from_secs(10),
+    };
+    let mut interner = Interner::default();
+    let samples = sample_profile(
+        &profile_of(cpu, Config::default()),
+        Some(&heap),
+        Side::Server,
+        Unit::Tick,
+        &|_| None,
+        &mut interner,
+    );
+    let c = Converted {
+        samples,
+        strings: interner.take_new(Side::Server),
+    };
+    let sources: Vec<_> = c
+        .samples
+        .kinds
+        .iter()
+        .map(|k| (k.source(), k.period))
+        .collect();
+    assert_eq!(
+        sources,
+        [
+            (SampleSource::Cpu, 4.0),
+            (SampleSource::Alloc, 1.0),
+            (SampleSource::Live, 1.0)
+        ]
+    );
+    let names: Vec<_> = c.samples.threads.iter().map(|t| c.text(t.name)).collect();
+    assert_eq!(names, ["tick", "worker"]);
+    let w = c.samples.weights.as_ref().unwrap();
+    let mut rows: Vec<_> = (0..w.node.len())
+        .map(|i| {
+            let path: Vec<_> = c.path(w.node[i]).into_iter().map(short).collect();
+            (w.kind[i], w.thread[i], path.join(">"), w.count[i])
+        })
+        .collect();
+    rows.sort();
+    assert_eq!(
+        rows,
+        [
+            (0, 0, "gamma>alpha".to_owned(), 1),
+            (1, 0, "gamma>beta".to_owned(), 3000),
+            (2, 0, "gamma>beta".to_owned(), 1000),
+            (2, 1, "alpha".to_owned(), 500),
+        ]
+    );
+    let o = overhead(
+        &profile_of(Aggregate::new(0), Config::default()),
+        Some(&heap),
+    );
+    assert_eq!(o.heap_samples, 3);
+}
@@ -0,0 +1,484 @@
+//! The GPU pass timers' readings as the capture's `gpu` messages (docs/perf-platform.md §3.5); apart from `perf_capture`, which only Linux has.
+use horizon_perf_format::Interner;
+use horizon_perf_format::v1::{
+    GpuBackend, GpuCounter, GpuCounts, GpuDevice, GpuFragmentUnit, GpuFrame, GpuFrames, GpuPart,
+    GpuPartCounts, GpuPartsMode, GpuPass, GpuPassSplit, GpuPasses, GpuSource, Side,
+};
+use std::time::Instant;
+
+use crate::gfx::pack_timing::{
+    Counters, FragmentUnit, GpuReadout, PartsMode, PassCounters, Readings, TimedFrame, TimedFrames,
+};
+
+/// Every time one timer's frames gave a pass or a part during a capture.
+#[derive(Default)]
+struct Times {
+    passes: Vec<(String, Vec<f32>)>,
+    parts: Vec<(String, Vec<(String, Vec<f32>)>)>,
+}
+
+fn times_of<'a>(list: &'a mut Vec<(String, Vec<f32>)>, name: &str) -> &'a mut Vec<f32> {
+    let i = match list.iter().position(|e| e.0 == name) {
+        Some(i) => i,
+        None => {
+            list.push((name.to_owned(), Vec::new()));
+            list.len() - 1
+        }
+    };
+    &mut list[i].1
+}
+
+impl Times {
+    fn add(&mut self, frame: &TimedFrame) {
+        for (pass, ms) in &frame.passes {
+            times_of(&mut self.passes, pass).push(*ms);
+        }
+        for (pass, parts) in &frame.parts {
+            let i = match self.parts.iter().position(|e| e.0 == *pass) {
+                Some(i) => i,
+                None => {
+                    self.parts.push((pass.clone(), Vec::new()));
+                    self.parts.len() - 1
+                }
+            };
+            for (part, ms) in parts {
+                times_of(&mut self.parts[i].1, part).push(*ms);
+            }
+        }
+    }
+
+    fn is_empty(&self) -> bool {
+        self.passes.is_empty() && self.parts.is_empty()
+    }
+
+    /// `readings` with its times the medians over the whole capture instead of its last frames.
+    fn medians_into(&self, readings: &Readings) -> Readings {
+        let median = |v: &[f32]| {
+            let mut v = v.to_vec();
+            v.sort_by(f32::total_cmp);
+            v[v.len() / 2]
+        };
+        Readings {
+            passes: self
+                .passes
+                .iter()
+                .map(|(name, v)| (name.clone(), median(v)))
+                .collect(),
+            parts: self
+                .parts
+                .iter()
+                .map(|(pass, parts)| {
+                    let parts = parts.iter().map(|(n, v)| (n.clone(), median(v))).collect();
+                    (pass.clone(), parts)
+                })
+                .collect(),
+            ..readings.clone()
+        }
+    }
+}
+
+/// A capture's timed frames on their way into `GpuFrames` blocks, every time kept for the whole capture's medians.
+#[derive(Default)]
+pub struct FrameLog {
+    pending: Vec<GpuFrame>,
+    cpu_frame_ms: Vec<f32>,
+    own: Times,
+    pack: Times,
+}
+
+impl FrameLog {
+    /// The CPU's own ms of one frame the window drew.
+    pub fn cpu_frame(&mut self, ms: f32) {
+        self.cpu_frame_ms.push(ms);
+    }
+
+    /// The frames timed since the last call; `t_of` puts a frame's start on the capture clock.
+    pub fn add(
+        &mut self,
+        frames: &TimedFrames,
+        t_of: impl Fn(Instant) -> f64,
+        strings: &mut Interner,
+    ) {
+        for (source, list, times) in [
+            (GpuSource::Horizon, &frames.own, &mut self.own),
+            (GpuSource::ShaderPack, &frames.pack, &mut self.pack),
+        ] {
+            for frame in list {
+                times.add(frame);
+                self.pending
+                    .push(frame_message(frame, source, t_of(frame.at), strings));
+            }
+        }
+    }
+
+    /// The frames and CPU frame times since the last block; none when there are neither.
+    pub fn take_block(&mut self, side: Side) -> Option<GpuFrames> {
+        if self.pending.is_empty() && self.cpu_frame_ms.is_empty() {
+            return None;
+        }
+        Some(GpuFrames {
+            side: side as i32,
+            frames: std::mem::take(&mut self.pending),
+            cpu_frame_ms: std::mem::take(&mut self.cpu_frame_ms),
+        })
+    }
+}
+
+fn frame_message(
+    frame: &TimedFrame,
+    source: GpuSource,
+    t: f64,
+    strings: &mut Interner,
+) -> GpuFrame {
+    let mut passes: Vec<GpuPass> = frame
+        .passes
+        .iter()
+        .map(|(name, ms)| GpuPass {
+            name: strings.intern(name),
+            ms: Some(*ms),
+            parts: Vec::new(),
+        })
+        .collect();
+    for (pass, parts) in &frame.parts {
+        let parts = parts
+            .iter()
+            .map(|(part, ms)| GpuPart {
+                name: strings.intern(part),
+                ms: *ms,
+            })
+            .collect();
+        let name = strings.intern(pass);
+        match passes.iter_mut().find(|p| p.name == name) {
+            Some(p) => p.parts = parts,
+            None => passes.push(GpuPass {
+                name,
+                ms: None,
+                parts,
+            }),
+        }
+    }
+    GpuFrame {
+        source: source as i32,
+        t,
+        total_ms: frame.total_ms,
+        passes,
+    }
+}
+
+fn backend(backend: wgpu::Backend) -> GpuBackend {
+    match backend {
+        wgpu::Backend::Vulkan => GpuBackend::Vulkan,
+        wgpu::Backend::Metal => GpuBackend::Metal,
+        wgpu::Backend::Dx12 => GpuBackend::Dx12,
+        wgpu::Backend::Gl => GpuBackend::Gl,
+        _ => GpuBackend::Other,
+    }
+}
+
+fn counts(c: Counters) -> GpuCounts {
+    GpuCounts {
+        vertex_shader_invocations: c.vertex_shader_invocations,
+        clipper_invocations: c.clipper_invocations,
+        clipper_primitives_out: c.clipper_primitives_out,
+        fragment_shader_invocations: c.fragment_shader_invocations,
+    }
+}
+
+fn counter(strings: &mut Interner, pass: &str, c: &PassCounters) -> GpuCounter {
+    GpuCounter {
+        pass: strings.intern(pass),
+        total: Some(counts(c.total)),
+        pixels: c.pixels,
+        parts: c
+            .parts
+            .iter()
+            .map(|(name, part)| GpuPartCounts {
+                name: strings.intern(name),
+                counts: Some(counts(*part)),
+            })
+            .collect(),
+    }
+}
+
+fn device(adapter: &wgpu::AdapterInfo, readings: &Readings) -> GpuDevice {
+    let driver = format!("{} {}", adapter.driver, adapter.driver_info);
+    GpuDevice {
+        adapter: adapter.name.clone(),
+        backend: backend(adapter.backend) as i32,
+        driver: driver.trim().to_owned(),
+        parts_mode: match readings.support.parts {
+            PartsMode::InsidePasses => GpuPartsMode::InsidePasses,
+            PartsMode::SeparatePasses => GpuPartsMode::SeparatePasses,
+        } as i32,
+        pass_split: match readings.support.parts {
+            PartsMode::InsidePasses => GpuPassSplit::DrawGroups,
+            PartsMode::SeparatePasses => GpuPassSplit::PassesOnly,
+        } as i32,
+        counters: readings.support.counters,
+        fragment_unit: match readings.support.fragment_unit {
+            None => GpuFragmentUnit::Unspecified,
+            Some(FragmentUnit::Pixel) => GpuFragmentUnit::Pixel,
+            Some(FragmentUnit::Quad) => GpuFragmentUnit::Quad,
+        } as i32,
+    }
+}
+
+fn section(
+    adapter: &wgpu::AdapterInfo,
+    side: Side,
+    source: GpuSource,
+    readings: &Readings,
+    strings: &mut Interner,
+) -> GpuPasses {
+    let mut passes: Vec<GpuPass> = readings
+        .passes
+        .iter()
+        .map(|(name, ms)| GpuPass {
+            name: strings.intern(name),
+            ms: Some(*ms),
+            parts: Vec::new(),
+        })
+        .collect();
+    for (pass, parts) in &readings.parts {
+        let name = strings.intern(pass);
+        let at = passes
+            .iter()
+            .position(|p| p.name == name)
+            .unwrap_or_else(|| {
+                passes.push(GpuPass {
+                    name,
+                    ms: None,
+                    parts: Vec::new(),
+                });
+                passes.len() - 1
+            });
+        passes[at].parts = parts
+            .iter()
+            .map(|(part, ms)| GpuPart {
+                name: strings.intern(part),
+                ms: *ms,
+            })
+            .collect();
+    }
+    GpuPasses {
+        side: side as i32,
+        device: Some(device(adapter, readings)),
+        passes,
+        counters: readings
+            .counters
+            .iter()
+            .map(|(pass, c)| counter(strings, pass, c))
+            .collect(),
+        source: source as i32,
+    }
+}
+
+/// One `GpuPasses` per timer that has timed something, its times the medians of `log` where it has them; the caller appends `strings`' new entries first.
+pub fn gpu_passes(
+    readout: &GpuReadout,
+    log: &FrameLog,
+    side: Side,
+    strings: &mut Interner,
+) -> Vec<GpuPasses> {
+    [
+        (GpuSource::Horizon, &readout.own, &log.own),
+        (GpuSource::ShaderPack, &readout.pack, &log.pack),
+    ]
+    .into_iter()
+    .filter_map(|(source, readings, times)| {
+        let readings = readings.as_ref().filter(|r| !r.is_empty())?;
+        let whole = (!times.is_empty()).then(|| times.medians_into(readings));
+        let readings = whole.as_ref().unwrap_or(readings);
+        Some(section(&readout.adapter, side, source, readings, strings))
+    })
+    .collect()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::gfx::pack_timing::DetailSupport;
+
+    fn adapter() -> wgpu::AdapterInfo {
+        wgpu::AdapterInfo {
+            name: "Test GPU".into(),
+            vendor: 0x10de,
+            device: 1,
+            device_type: wgpu::DeviceType::DiscreteGpu,
+            device_pci_bus_id: String::new(),
+            driver: "NVIDIA".into(),
+            driver_info: "570.1".into(),
+            backend: wgpu::Backend::Vulkan,
+            subgroup_min_size: 0,
+            subgroup_max_size: 0,
+            transient_saves_memory: None,
+            limit_bucket: None,
+        }
+    }
+
+    fn support(unit: Option<FragmentUnit>) -> DetailSupport {
+        DetailSupport {
+            parts: PartsMode::InsidePasses,
+            encoder_stamps: true,
+            counters: true,
+            fragment_unit: unit,
+        }
+    }
+
+    #[test]
+    fn known_medians_parts_and_counters_come_through_with_their_names() {
+        let c = |v, f| Counters {
+            vertex_shader_invocations: v,
+            clipper_invocations: 2_050_000,
+            clipper_primitives_out: 1_200_000,
+            fragment_shader_invocations: f,
+        };
+        let own = Readings {
+            passes: vec![("World".into(), 1.5), ("HUD".into(), 0.25)],
+            parts: vec![("GPU culling".into(), vec![("cull".into(), 0.125)])],
+            counters: vec![(
+                "World".into(),
+                PassCounters {
+                    total: c(4_100_000, 6_300_000),
+                    pixels: 2_073_600,
+                    parts: vec![
+                        ("before translucent".into(), c(3_000_000, 5_100_000)),
+                        ("translucent terrain".into(), c(1_100_000, 1_200_000)),
+                    ],
+                },
+            )],
+            support: support(Some(FragmentUnit::Quad)),
+        };
+        let readout = GpuReadout {
+            adapter: adapter(),
+            own: Some(own),
+            pack: None,
+        };
+        let mut strings = Interner::default();
+        let got = gpu_passes(&readout, &FrameLog::default(), Side::Client, &mut strings);
+        assert_eq!(got.len(), 1);
+        let g = &got[0];
+        assert_eq!((g.side(), g.source()), (Side::Client, GpuSource::Horizon));
+        let d = g.device.as_ref().unwrap();
+        assert_eq!(d.adapter, "Test GPU");
+        assert_eq!(d.backend(), GpuBackend::Vulkan);
+        assert_eq!(d.driver, "NVIDIA 570.1");
+        assert_eq!(d.parts_mode(), GpuPartsMode::InsidePasses);
+        assert!(d.counters);
+        assert_eq!(d.fragment_unit(), GpuFragmentUnit::Quad);
+
+        // World, HUD, then the pass known only through its parts.
+        let entries = strings.take_new(Side::Client);
+        let name = |id: u32| entries.iter().find(|e| e.id == id).unwrap().text.as_str();
+        let named: Vec<_> = g.passes.iter().map(|p| name(p.name)).collect();
+        assert_eq!(named, ["World", "HUD", "GPU culling"]);
+        let shown: Vec<_> = g.passes.iter().map(|p| p.ms).collect();
+        assert_eq!(shown, [Some(1.5), Some(0.25), None]);
+        assert_eq!(name(g.passes[2].parts[0].name), "cull");
+        assert_eq!(g.passes[2].parts[0].ms, 0.125);
+        let counted = &g.counters[0];
+        assert_eq!(counted.pixels, 2_073_600);
+        assert_eq!(
+            counted.total.as_ref().unwrap().fragment_shader_invocations,
+            6_300_000
+        );
+        assert_eq!(counted.parts.len(), 2);
+        assert_eq!(
+            counted.parts[1]
+                .counts
+                .as_ref()
+                .unwrap()
+                .vertex_shader_invocations,
+            1_100_000
+        );
+        // The pass's counters and its time name the same string.
+        assert_eq!(counted.pass, g.passes[0].name);
+    }
+
+    #[test]
+    fn a_timer_that_timed_nothing_adds_no_section() {
+        let idle = Readings {
+            passes: Vec::new(),
+            parts: Vec::new(),
+            counters: Vec::new(),
+            support: support(None),
+        };
+        let pack = Readings {
+            passes: vec![("composite".into(), 0.75)],
+            ..idle.clone()
+        };
+        let readout = GpuReadout {
+            adapter: adapter(),
+            own: Some(idle),
+            pack: Some(pack),
+        };
+        let got = gpu_passes(
+            &readout,
+            &FrameLog::default(),
+            Side::Client,
+            &mut Interner::default(),
+        );
+        assert_eq!(got.len(), 1);
+        assert_eq!(got[0].source(), GpuSource::ShaderPack);
+        assert_eq!(
+            got[0].device.as_ref().unwrap().fragment_unit(),
+            GpuFragmentUnit::Unspecified
+        );
+    }
+
+    #[test]
+    fn the_end_section_takes_the_whole_capture_median_and_each_block_its_frames() {
+        let start = Instant::now();
+        let frame = |i: u32, world: f32| TimedFrame {
+            at: start + std::time::Duration::from_millis(u64::from(i) * 10),
+            total_ms: Some(world + 1.0),
+            passes: vec![("World".into(), world), ("HUD".into(), 0.5)],
+            parts: vec![("World".into(), vec![("sky".into(), world / 4.0)])],
+        };
+        let mut log = FrameLog::default();
+        let mut strings = Interner::default();
+        let worlds = [1.0, 2.0, 3.0, 4.0, 100.0];
+        let frames = TimedFrames {
+            own: worlds
+                .iter()
+                .enumerate()
+                .map(|(i, &w)| frame(i as u32, w))
+                .collect(),
+            pack: Vec::new(),
+        };
+        log.add(
+            &frames,
+            |at| at.duration_since(start).as_secs_f64(),
+            &mut strings,
+        );
+        log.cpu_frame(6.0);
+        let block = log.take_block(Side::Client).expect("a block");
+        assert_eq!(block.frames.len(), 5);
+        assert_eq!(block.cpu_frame_ms, [6.0]);
+        assert!((block.frames[4].t - 0.04).abs() < 1e-9);
+        assert_eq!(block.frames[4].total_ms, Some(101.0));
+        assert_eq!(block.frames[4].passes[0].parts[0].ms, 25.0);
+        assert!(log.take_block(Side::Client).is_none());
+
+        // The timer's own median (9.0) is of its last frames; the capture's is the third of five sorted.
+        let own = Readings {
+            passes: vec![("World".into(), 9.0)],
+            parts: Vec::new(),
+            counters: Vec::new(),
+            support: support(None),
+        };
+        let readout = GpuReadout {
+            adapter: adapter(),
+            own: Some(own),
+            pack: None,
+        };
+        let got = gpu_passes(&readout, &log, Side::Client, &mut strings);
+        let world = &got[0].passes[0];
+        assert_eq!(world.ms, Some(3.0));
+        assert_eq!(world.parts[0].ms, 0.75);
+        assert_eq!(
+            got[0].device.as_ref().unwrap().pass_split(),
+            GpuPassSplit::DrawGroups
+        );
+    }
+}
@@ -864,11 +864,21 @@ impl TextField {
        self.set_highlight(m, pos);
    }
    /// `onClick`: the cursor where the mouse is (`findClickedPositionInText`).
-    pub fn click(&mut self, m: &Measure, x: f64, extend: bool) {
+    /// `EditBox.onClick` / `MultiLineEditBox.onClick`: a double click selects
+    /// the word the pointer is in (`EditBox.selectWord`), any other click
+    /// places the caret there.
+    pub fn click(&mut self, m: &Measure, x: f64, extend: bool, double: bool) {
        let pos = (x.floor() as i32 - self.text_x()).min(self.inner_width());
        let rest = sub(&self.value, self.display, chars(&self.value));
        let at = self.display + m.plain(&rest, pos, false);
-        self.move_cursor_to(m, at, extend);
+        if double {
+            let start = crate::ui::word_position(&self.value, -1, at);
+            let end = crate::ui::word_position(&self.value, 1, at);
+            self.move_cursor_to(m, start, false);
+            self.move_cursor_to(m, end, true);
+        } else {
+            self.move_cursor_to(m, at, extend);
+        }
    }
    pub fn contains(&self, x: f64, y: f64) -> bool {
        x >= self.x as f64
@@ -222,11 +222,6 @@ impl<P: Copy, S: Copy> Lines<P, S> {
        }
        self.y += style::GROUP_GAP;
    }
-    /// A group of rows under its page's own name (`list`'s `page_name`), for pages named at run
-    /// time, such as a resource pack's config entries (`pack_options_ui`).
-    pub(crate) fn titled(&mut self, page: P, rows: Vec<S>) {
-        self.group(page, "", rows);
-    }
    /// The lines and the content's height.
    pub(crate) fn finish(self) -> (Vec<Line<P, S>>, f32) {
        (self.lines, (self.y - style::GROUP_GAP).max(0.0))
@@ -310,6 +305,9 @@ pub(crate) fn search_field(
    let frame = [x, y, clear[0] - x, h];
    search.frame = Some(frame);
    search.draw(batch, atlas, None);
+    if ui::hovered(cursor, x, y, frame[2], h) {
+        crate::widgets::text_cursor(true, true);
+    }
    if search.value.is_empty() && !focused {
        let hint = Text::literal(search.message.clone());
        batch.text_styled(atlas, &hint, x + 5.0, search.y, style::muted(), true);
@@ -349,8 +347,7 @@ pub(crate) fn plate(batch: &mut HudBatch, atlas: &HudAtlas, cols: &Columns, head
 }

 /// The list, clipped to its view: each group's panel, then its names and rows on it. `row`
-/// draws a setting at its `y`; `page_name` names a page, and a group without a name of its own
-/// (`Lines::titled`), in the player's language.
+/// draws a setting at its `y`; `page_name` names a page, in the player's language.
 pub(crate) fn list<P: Copy, S: Copy>(
    batch: &mut HudBatch,
    atlas: &HudAtlas,
@@ -383,7 +380,6 @@ pub(crate) fn list<P: Copy, S: Copy>(
        }
        let Some(setting) = line.setting else {
            let (name, color, dy) = match line.group {
-                Some(("", _)) => (page_name(line.page), style::muted(), 3.0),
                Some((name, _)) => (lang::get(name), style::muted(), 3.0),
                None => (page_name(line.page), style::accent(), 4.0),
            };
@@ -949,22 +945,10 @@ pub(crate) fn dock_note(
    }
 }

-/// Done or Undo at the foot of the page list.
+/// Done, Undo or Apply at the foot of the page list, registered for a controller. Its label
+/// leaves `room` at its left for a controller's glyph: a button that declared its job gets one,
+/// as vanilla's do (`ui::action_button`), which a half-width Undo or Apply needs.
 pub(crate) fn foot_button(
-    batch: &mut HudBatch,
-    atlas: &HudAtlas,
-    rect: [f32; 4],
-    label: &Text,
-    cursor: (f32, f32),
-    flags: (bool, bool),
-) {
-    foot_button_with_room(batch, atlas, rect, label, cursor, flags, 0.0);
-}
-
-/// A foot button whose label leaves `room` at its left for a controller's glyph: a button that
-/// declared its job gets one, as vanilla's do (`ui::action_button`), which a half-width Undo or
-/// Apply needs.
-fn foot_button_with_room(
    batch: &mut HudBatch,
    atlas: &HudAtlas,
    rect: [f32; 4],
@@ -2411,7 +2395,7 @@ impl<S: Screen + Default> Hosted for Shell<S> {
                }
                None => 0.0,
            };
-            foot_button_with_room(batch, atlas, rect, &label, cursor, flags, room);
+            foot_button(batch, atlas, rect, &label, cursor, flags, room);
        }
    }
    fn click(
@@ -93,18 +93,17 @@ pub fn unpack(value: &str, signature: Signature, valid_uris: &[impl AsRef<str>])
        signed: signature == Signature::Signed,
        ..empty.clone()
    };
-    // Each texture is loaded independently: an invalid or disallowed URL for one
-    // texture (cape, elytra) must not drop another (the skin). Vanilla's
-    // SkinManager works the same way.
+    // Authlib's MinecraftServicesSessionService validates every URL in
+    // unpackTextures before returning any textures. A bad cape rejects the skin too.
    for (kind, texture) in textures {
        let Some(url) = texture.get("url").and_then(|u| u.as_str()) else {
-            continue;
+            return empty;
        };
        let allowed = valid_uris
            .iter()
            .any(|u| url.starts_with(&u.as_ref().replace("{textureId}", "")));
        if !allowed {
-            continue;
+            return empty;
        }
        if kind == "SKIN" {
            out.slim = texture
@@ -1388,10 +1387,9 @@ mod tests {
                    &super::TEXTURE_URIS,
                );
                assert_eq!(textures.slim, slim && !url.contains("evil"));
-                // Textures are judged per URL (vanilla's SkinManager): the
-                // cape's URL is always allowed here, so it is kept even when
-                // the skin's URL is not.
-                assert!(textures.cape.is_some());
+                // Authlib rejects the whole payload if any URL is invalid,
+                // including the allowed cape when the skin is disallowed.
+                assert_eq!(textures.cape.is_some(), !url.contains("evil"));
                assert_eq!(parsed.skin.is_some(), !url.contains("evil"));
                assert!(std::sync::Arc::ptr_eq(&parsed, &cache.get(&profile)));
            }
@@ -1544,18 +1542,14 @@ mod tests {
        assert!(t.slim);
        assert!(!unpack(wide, Signature::Signed, &TEXTURE_URIS).slim);
    }
-    /// `unpack` keeps each texture independently: a cape from another origin
-    /// must not drop the skin.
+    /// Authlib's `MinecraftServicesSessionService` rejects the whole profile in
+    /// `unpackTextures` when any texture URL is outside the allowed origins.
    #[test]
-    fn unpack_keeps_the_skin_when_another_texture_is_rejected() {
+    fn unpack_rejects_the_skin_when_another_texture_is_rejected() {
        use super::{Signature, TEXTURE_URIS, unpack};
        let mixed = "eyJ0ZXh0dXJlcyI6IHsiU0tJTiI6IHsidXJsIjogImh0dHBzOi8vdGV4dHVyZXMubWluZWNyYWZ0Lm5ldC90ZXh0dXJlL3NraW4xIn0sICJDQVBFIjogeyJ1cmwiOiAiaHR0cHM6Ly9ldmlsLmV4YW1wbGUvdGV4dHVyZS9jYXBlMSJ9fX0=";
        let t = unpack(mixed, Signature::Unsigned, &TEXTURE_URIS);
-        assert_eq!(
-            t.skin.as_deref(),
-            Some("https://textures.minecraft.net/texture/skin1")
-        );
-        assert_eq!(t.cape, None);
+        assert_eq!(t, super::Textures::default());
    }
    #[test]
    fn profiles_parse_like_resolvable_profiles() {
@@ -1,10 +1,4 @@
-//! Named timings within a frame, for finding what makes a frame slow:
-//! `HORIZON_SPIKES=MS` prints the spans of every frame whose CPU time
-//! exceeds MS milliseconds, and of every server tick (dedicated or
-//! integrated) longer than MS. Each span keeps its wall time and the
-//! thread's CPU time inside it, so a span that waited (for a lock, the GPU
-//! or a core on a busy machine) shows apart from one that worked. Costs two
-//! clock reads per span when enabled and a relaxed load otherwise.
+//! Named timings (wall and thread CPU) of a frame or tick, on with `HORIZON_SPIKES` or while a capture records; the slow ones go to the slow ring, not as span lists to the log.
 use std::{
    cell::{Cell, RefCell},
    sync::atomic::{AtomicBool, Ordering},
@@ -58,10 +52,10 @@ pub fn record_here(on: bool) {
 /// Whether this thread records spans: all of them on, or [`record_here`].
 #[inline]
 pub fn recording_here() -> bool {
-    ENABLED.load(Ordering::Relaxed) || HERE.with(Cell::get) || trace::on()
+    ENABLED.load(Ordering::Relaxed) || HERE.with(Cell::get) || timeline::on()
 }
-/// The thread's CPU time when spans are on for every thread (`HORIZON_SPIKES`): only they
-/// print it.
+/// The thread's CPU time when spans are on for every thread (`HORIZON_SPIKES`): spans recorded
+/// by `record_here` alone keep wall time only.
 #[inline]
 fn cpu_if_enabled() -> Option<Duration> {
    if ENABLED.load(Ordering::Relaxed) {
@@ -82,31 +76,41 @@ pub fn time<T>(name: &'static str, f: impl FnOnce() -> T) -> T {
 pub struct Guard {
    open: Option<(&'static str, Instant, Option<Duration>, u8)>,
    _heap: Option<horizon_threads::heap_census::Tag>,
+    /// The sampler's span before this one.
+    outer: u16,
 }
 /// Start a span named `name` that ends when the returned [`Guard`] is dropped.
 #[inline]
 pub fn guard(name: &'static str) -> Guard {
    let _heap = horizon_threads::heap_tag(name);
+    let outer = horizon_threads::work::enter_span(name);
    if !recording_here() {
-        return Guard { open: None, _heap };
+        return Guard {
+            open: None,
+            _heap,
+            outer,
+        };
    }
    let depth = DEPTH.with(|d| d.replace(d.get().saturating_add(1)));
    Guard {
        open: Some((name, Instant::now(), cpu_if_enabled(), depth)),
        _heap,
+        outer,
    }
 }
 impl Drop for Guard {
    fn drop(&mut self) {
+        horizon_threads::work::leave_span(self.outer);
        let Some((name, started, cpu, depth)) = self.open.take() else {
            return;
        };
-        let ms = started.elapsed().as_secs_f32() * 1000.0;
+        let elapsed = started.elapsed();
+        let ms = elapsed.as_secs_f32() * 1000.0;
        let cpu_ms = cpu
            .and_then(|start| Some((thread_cpu()?, start)))
            .map_or(ms, |(end, start)| (end - start).as_secs_f32() * 1000.0);
        DEPTH.with(|d| d.set(depth));
-        trace::span(name, started, ms);
+        timeline::span(name, started, elapsed, depth);
        push(Span {
            name,
            ms,
@@ -115,6 +119,22 @@ impl Drop for Guard {
        });
    }
 }
+/// How many spans this thread holds.
+fn recorded() -> usize {
+    SPANS.with(|s| s.borrow().len())
+}
+/// Moves the spans recorded since `mark` one level in: they ran inside the lap now ending.
+fn nest_since(mark: usize, depth: u8) {
+    SPANS.with(|s| {
+        let mut s = s.borrow_mut();
+        let start = mark.min(s.len());
+        for span in &mut s[start..] {
+            if span.depth >= depth {
+                span.depth = span.depth.saturating_add(1);
+            }
+        }
+    });
+}
 /// Keeps a finished span for the thread's next [`take_raw`].
 fn push(span: Span) {
    SPANS.with(|s| {
@@ -125,22 +145,6 @@ fn push(span: Span) {
        s.push(span);
    });
 }
-/// Attach per-tick counts without interpreting them as durations.
-pub fn counters(counts: &[(&str, u64)]) {
-    if !enabled() {
-        return;
-    }
-    NOTES.with(|n| {
-        n.borrow_mut().push((
-            0.0,
-            counts
-                .iter()
-                .map(|(name, count)| format!("{name}={count}"))
-                .collect::<Vec<_>>()
-                .join(", "),
-        ))
-    });
-}
 /// Notes that one step inside a span took `ms` milliseconds doing `what` (one player's
 /// packets, say), when this thread records spans and the step took at least [`NOTE_MS`]: a
 /// span says where a slow tick went, its notes whose doing it was. Only the slowest few are
@@ -173,34 +177,36 @@ pub fn take_notes() -> Vec<(f32, String)> {
 }
 /// Consecutive steps of one function timed as spans: each [`Laps::lap`] records the time since
 /// the previous one (or since [`laps`]) under its name. Nothing is read while spans are off.
-pub struct Laps(Option<(Instant, Option<Duration>)>);
+pub struct Laps(Option<(Instant, Option<Duration>, usize)>);
 /// Start timing the steps of a function (see [`Laps`]).
 #[inline]
 pub fn laps() -> Laps {
-    Laps(recording_here().then(|| (Instant::now(), cpu_if_enabled())))
+    Laps(recording_here().then(|| (Instant::now(), cpu_if_enabled(), recorded())))
 }
 impl Laps {
    /// Record the step that just ended under `name`, and start the next.
    #[inline]
    pub fn lap(&mut self, name: &'static str) {
-        let Some((started, cpu)) = &mut self.0 else {
+        let Some((started, cpu, mark)) = &mut self.0 else {
            return;
        };
        let now = Instant::now();
        let now_cpu = cpu.and_then(|_| thread_cpu());
-        let ms = (now - *started).as_secs_f32() * 1000.0;
+        let elapsed = now - *started;
+        let ms = elapsed.as_secs_f32() * 1000.0;
        let cpu_ms = now_cpu
            .zip(*cpu)
            .map_or(ms, |(end, start)| (end - start).as_secs_f32() * 1000.0);
        let depth = DEPTH.with(Cell::get);
-        trace::span(name, *started, ms);
+        timeline::span(name, *started, elapsed, depth);
+        nest_since(*mark, depth);
        push(Span {
            name,
            ms,
            cpu_ms,
            depth,
        });
-        (*started, *cpu) = (now, now_cpu);
+        (*started, *cpu, *mark) = (now, now_cpu, recorded());
    }
 }
 /// The CPU time this thread has used, where the platform tells it: a tick
@@ -283,173 +289,176 @@ pub fn merge(spans: &[Span]) -> Vec<Span> {
    sums.sort_by(|a, b| b.ms.total_cmp(&a.ms));
    sums
 }
-/// `name wall` for spans of at least 0.5 ms, with `/cpu` when the thread
-/// worked for less than nine tenths of it: the slow-frame and slow-tick lines.
-pub fn describe(spans: &[Span]) -> String {
-    let list: Vec<String> = spans
-        .iter()
-        .filter(|s| s.ms >= 0.5)
-        .map(|s| {
-            if s.cpu_ms < s.ms * 0.9 {
-                format!("{} {:.1}/{:.1}", s.name, s.ms, s.cpu_ms)
-            } else {
-                format!("{} {:.1}", s.name, s.ms)
-            }
-        })
-        .collect();
-    list.join(", ")
-}
-
-/// The run's timeline: every span ([`time`], [`guard`], [`Laps::lap`]) on every thread, as
-/// Chrome trace events that Perfetto (ui.perfetto.dev) opens as they are. `HORIZON_TRACE=FILE`
-/// writes it from the start; [`start`](trace::start) and [`stop`](trace::stop) write one for a
-/// while (`horizon-trace` on a dedicated server's console, `trace` on the control socket). Spans
-/// show on their threads where they ran, nested by time, so what ran beside what, and what a
-/// thread waited for, can be read off. Off, a span costs one relaxed load more.
-pub mod trace {
+/// The run's timeline: every span on every thread, kept in per-thread buffers until a capture drains them as `timeline` chunks.
+pub mod timeline {
    use std::{
-        cell::Cell,
-        fs::File,
-        io::{BufWriter, Write as _},
-        path::Path,
+        cell::RefCell,
        sync::{
-            Mutex, PoisonError,
+            Arc, Mutex, PoisonError,
            atomic::{AtomicBool, AtomicU32, Ordering},
        },
-        time::Instant,
+        time::{Duration, Instant},
    };

+    /// The most spans a thread holds between two drains; a thread that records more drops them.
+    const THREAD_EVENTS_MAX: usize = 1 << 18;
+
    static ON: AtomicBool = AtomicBool::new(false);
-    static SINK: Mutex<Option<Sink>> = Mutex::new(None);
-    /// Counts the traces started: a thread names itself again in each one.
-    static TRACES: AtomicU32 = AtomicU32::new(0);
-    static NEXT_THREAD: AtomicU32 = AtomicU32::new(1);
-    thread_local! {
-        /// This thread's id in traces (0: none yet).
-        static THREAD: Cell<u32> = const { Cell::new(0) };
-        /// The trace this thread last named itself in.
-        static NAMED_IN: Cell<u32> = const { Cell::new(0) };
-    }
-    /// How often a trace's buffer goes to the file, at most: a run that ends without
-    /// [`stop`] loses no more than this.
-    const FLUSH_EVERY: std::time::Duration = std::time::Duration::from_secs(1);
+    static GENERATION: AtomicU32 = AtomicU32::new(0);
+    static RUN: Mutex<Option<Run>> = Mutex::new(None);

-    struct Sink {
-        file: BufWriter<File>,
+    struct Run {
        origin: Instant,
-        /// Until when it records ([`start`]'s `seconds`).
-        until: Option<Instant>,
-        flushed: Instant,
-        /// Events written: the next one is preceded by a comma.
-        events: u64,
-    }
-    impl Sink {
-        fn event(&mut self, event: std::fmt::Arguments) {
-            let comma = if self.events == 0 { "" } else { ",\n" };
-            let _ = write!(self.file, "{comma}{{\"pid\":1,{event}}}");
-            self.events += 1;
-        }
+        threads: Vec<Arc<Mutex<Thread>>>,
    }

-    /// Whether a trace is being written.
+    struct Thread {
+        name: String,
+        label: String,
+        events: Vec<Event>,
+    }
+
+    /// This thread's buffer in the timeline it last joined.
+    struct Mine {
+        generation: u32,
+        origin: Instant,
+        thread: Arc<Mutex<Thread>>,
+    }
+
+    thread_local! {
+        static MINE: RefCell<Option<Mine>> = const { RefCell::new(None) };
+    }
+
+    /// One finished span.
+    #[derive(Clone, Copy, Debug, PartialEq, Eq)]
+    pub struct Event {
+        pub name: &'static str,
+        /// Microseconds from the timeline's start.
+        pub start_us: u64,
+        pub dur_us: u32,
+        /// How many spans it ran inside on its thread.
+        pub depth: u8,
+    }
+
+    /// The spans one thread finished since the last drain, in the order they finished.
+    #[derive(Debug, PartialEq, Eq)]
+    pub struct ThreadEvents {
+        /// The thread's name; threads alive together under one name get `#2`, `#3`... after it.
+        pub thread: String,
+        pub events: Vec<Event>,
+    }
+
+    /// Whether a timeline is being recorded.
    #[inline]
    pub fn on() -> bool {
        ON.load(Ordering::Relaxed)
    }

-    /// Starts a trace written to `path` (replacing a trace being written), for `seconds` or
-    /// until [`stop`].
-    pub fn start(path: &Path, seconds: Option<u32>) -> std::io::Result<()> {
-        let mut file = BufWriter::with_capacity(1 << 18, File::create(path)?);
-        file.write_all(b"[\n")?;
-        let now = Instant::now();
-        let sink = Sink {
-            file,
-            origin: now,
-            until: seconds.map(|s| now + std::time::Duration::from_secs(u64::from(s))),
-            flushed: now,
-            events: 0,
-        };
-        let mut slot = SINK.lock().unwrap_or_else(PoisonError::into_inner);
-        if let Some(old) = slot.take() {
-            close(old);
+    /// Starts recording, timed from `origin`; false when a timeline already runs (the process has one).
+    pub fn start(origin: Instant) -> bool {
+        let mut run = RUN.lock().unwrap_or_else(PoisonError::into_inner);
+        if run.is_some() {
+            return false;
        }
-        *slot = Some(sink);
-        TRACES.fetch_add(1, Ordering::Relaxed);
+        *run = Some(Run {
+            origin,
+            threads: Vec::new(),
+        });
+        GENERATION.fetch_add(1, Ordering::Relaxed);
        ON.store(true, Ordering::Relaxed);
-        Ok(())
+        true
    }

-    /// Starts the trace `HORIZON_TRACE` names, if it names one.
-    pub fn start_from_env() {
-        if let Some(path) = std::env::var_os("HORIZON_TRACE")
-            && let Err(e) = start(Path::new(&path), None)
-        {
-            log::warn!("Horizon: HORIZON_TRACE: {e}");
-        }
+    /// Takes what the threads finished since the last call.
+    pub fn drain() -> Vec<ThreadEvents> {
+        let run = RUN.lock().unwrap_or_else(PoisonError::into_inner);
+        run.as_ref().map_or_else(Vec::new, take_all)
    }

-    /// Ends the trace being written: the file is complete JSON. The events written so far
-    /// and whether one was being written.
-    pub fn stop() -> Option<u64> {
+    /// Stops recording and returns what the threads finished since the last drain.
+    pub fn finish() -> Vec<ThreadEvents> {
        ON.store(false, Ordering::Relaxed);
-        let sink = SINK.lock().unwrap_or_else(PoisonError::into_inner).take()?;
-        let events = sink.events;
-        close(sink);
-        Some(events)
+        let run = RUN.lock().unwrap_or_else(PoisonError::into_inner).take();
+        run.as_ref().map_or_else(Vec::new, take_all)
    }

-    /// Whether the trace being written has run its time ([`start`]'s `seconds`): the caller
-    /// then [`stop`]s it.
-    pub fn due() -> bool {
-        on() && SINK
-            .lock()
-            .unwrap_or_else(PoisonError::into_inner)
-            .as_ref()
-            .and_then(|s| s.until)
-            .is_some_and(|until| Instant::now() >= until)
+    fn take_all(run: &Run) -> Vec<ThreadEvents> {
+        run.threads
+            .iter()
+            .filter_map(|thread| {
+                let mut thread = thread.lock().unwrap_or_else(PoisonError::into_inner);
+                (!thread.events.is_empty()).then(|| ThreadEvents {
+                    thread: thread.label.clone(),
+                    events: std::mem::take(&mut thread.events),
+                })
+            })
+            .collect()
    }

-    fn close(mut sink: Sink) {
-        let _ = sink.file.write_all(b"\n]\n");
-        let _ = sink.file.flush();
+    /// Takes a buffer for this thread: the one of an exited thread of the same name, else a new one.
+    fn join() -> Option<Mine> {
+        let mut slot = RUN.lock().unwrap_or_else(PoisonError::into_inner);
+        let run = slot.as_mut()?;
+        let name = std::thread::current()
+            .name()
+            .unwrap_or("unnamed")
+            .to_owned();
+        let of_name =
+            |t: &Arc<Mutex<Thread>>| t.lock().unwrap_or_else(PoisonError::into_inner).name == name;
+        let thread = match run
+            .threads
+            .iter()
+            .find(|t| Arc::strong_count(t) == 1 && of_name(t))
+        {
+            Some(exited) => Arc::clone(exited),
+            None => {
+                let same = run.threads.iter().filter(|t| of_name(t)).count();
+                let label = if same == 0 {
+                    name.clone()
+                } else {
+                    format!("{name} #{}", same + 1)
+                };
+                let thread = Arc::new(Mutex::new(Thread {
+                    name,
+                    label,
+                    events: Vec::new(),
+                }));
+                run.threads.push(Arc::clone(&thread));
+                thread
+            }
+        };
+        Some(Mine {
+            generation: GENERATION.load(Ordering::Relaxed),
+            origin: run.origin,
+            thread,
+        })
    }

-    /// A span of this thread from `started`, `ms` long.
-    pub(super) fn span(name: &'static str, started: Instant, ms: f32) {
+    /// A span of this thread from `started`, `elapsed` long, inside `depth` others.
+    pub(super) fn span(name: &'static str, started: Instant, elapsed: Duration, depth: u8) {
        if !on() {
            return;
        }
-        let tid = THREAD.with(|t| {
-            if t.get() == 0 {
-                t.set(NEXT_THREAD.fetch_add(1, Ordering::Relaxed));
+        let generation = GENERATION.load(Ordering::Relaxed);
+        let _ = MINE.try_with(|mine| {
+            let mut mine = mine.borrow_mut();
+            if mine.as_ref().is_none_or(|m| m.generation != generation) {
+                *mine = join();
+            }
+            let Some(mine) = mine.as_ref() else {
+                return;
+            };
+            let event = Event {
+                name,
+                start_us: started.saturating_duration_since(mine.origin).as_micros() as u64,
+                dur_us: elapsed.as_micros().min(u128::from(u32::MAX)) as u32,
+                depth,
+            };
+            let mut thread = mine.thread.lock().unwrap_or_else(PoisonError::into_inner);
+            if thread.events.len() < THREAD_EVENTS_MAX {
+                thread.events.push(event);
            }
-            t.get()
        });
-        let trace = TRACES.load(Ordering::Relaxed);
-        let mut slot = SINK.lock().unwrap_or_else(PoisonError::into_inner);
-        let Some(sink) = slot.as_mut() else {
-            return;
-        };
-        if NAMED_IN.with(|n| n.replace(trace)) != trace {
-            let name = std::thread::current()
-                .name()
-                .unwrap_or("unnamed")
-                .replace(['"', '\\'], "_");
-            sink.event(format_args!(
-                r#""ph":"M","name":"thread_name","tid":{tid},"args":{{"name":"{name}"}}"#
-            ));
-        }
-        let ts = started.saturating_duration_since(sink.origin).as_secs_f64() * 1e6;
-        sink.event(format_args!(
-            r#""ph":"X","name":"{name}","tid":{tid},"ts":{ts:.3},"dur":{:.3}"#,
-            f64::from(ms) * 1e3
-        ));
-        let now = Instant::now();
-        if now.duration_since(sink.flushed) >= FLUSH_EVERY {
-            let _ = sink.file.flush();
-            sink.flushed = now;
-        }
    }
 }

@@ -654,6 +663,46 @@ mod tests {
        SWITCH.lock().unwrap_or_else(|e| e.into_inner())
    }

+    /// Samples taken inside a named span carry its id, with spans off, and the span is left after it.
+    #[cfg(target_os = "linux")]
+    #[test]
+    fn samples_inside_a_span_carry_its_id() {
+        use horizon_threads::{sampler, work};
+        use std::time::{Duration, Instant};
+        let worker = std::thread::spawn(|| {
+            assert!(sampler::sampled_thread("spans-id-test"));
+            let config = sampler::Config {
+                hz: 1000,
+                ..Default::default()
+            };
+            let session = sampler::start(config, |n| n == "spans-id-test").unwrap();
+            let busy = |ms| {
+                let until = Instant::now() + Duration::from_millis(ms);
+                while Instant::now() < until {
+                    std::hint::black_box(0);
+                }
+            };
+            super::time("spans_id_test_named", || busy(60));
+            assert_eq!(sampler::span(), 0);
+            busy(60);
+            let mut spans = Vec::new();
+            session.stop(|_, r| spans.push(r.ctx.span));
+            spans
+        });
+        let spans = worker.join().unwrap();
+        let inside = |s: &u16| work::name(work::Space::Span, *s) == Some("spans_id_test_named");
+        let (named, plain) = (
+            spans.iter().filter(|s| inside(s)).count(),
+            spans.iter().filter(|s| **s == 0).count(),
+        );
+        assert!(
+            named > 30 && plain > 30,
+            "{named} named, {plain} outside of {} samples",
+            spans.len()
+        );
+        assert_eq!(named + plain, spans.len(), "no other span id");
+    }
+
    /// A slow tick's notes are its slowest steps, slowest first; short steps and steps on a
    /// thread that records no spans leave none.
    #[test]
@@ -680,8 +729,7 @@ mod tests {
        assert!(super::take_notes().is_empty(), "taking them clears them");
    }

-    /// Spans of one name add up; a span the thread spent mostly waiting
-    /// shows its CPU time after the wall time, short ones are left out.
+    /// Spans of one name add up, the slowest first; a span that waited keeps its small CPU time.
    #[test]
    fn spans_sum_by_name_and_show_waits() {
        super::SPANS.with(|s| {
@@ -723,7 +771,6 @@ mod tests {
            }
        );
        assert_eq!((spans[1].name, spans[1].ms), ("tick", 5.0));
-        assert_eq!(super::describe(&spans), "submit 30.0/0.2, tick 5.0");
        assert!(super::take().is_empty());
    }

@@ -843,6 +890,22 @@ mod tests {
        assert!(spans[0].ms >= 2.0);
    }

+    /// A span that ran during a lap belongs inside that lap, and not inside the next one.
+    #[test]
+    fn a_span_during_a_lap_nests_under_that_lap() {
+        let _switch = spans_switch();
+        let _ = super::take_raw();
+        super::enable(true);
+        let mut laps = super::laps();
+        super::time("inner", || {});
+        laps.lap("first");
+        laps.lap("second");
+        super::enable(false);
+        let spans = super::take_raw();
+        let depths: Vec<_> = spans.iter().map(|s| (s.name, s.depth)).collect();
+        assert_eq!(depths, [("inner", 1), ("first", 0), ("second", 0)]);
+    }
+
    /// The thread's CPU clock moves with work done on it, not with time
    /// spent asleep.
    #[cfg(any(unix, all(windows, target_arch = "x86_64")))]
@@ -865,4 +928,74 @@ mod tests {
        assert!(slept.as_millis() < 25, "{slept:?} while asleep");
        assert!(worked.as_millis() >= 10, "{worked:?} while busy");
    }
+
+    /// Each thread's finished spans reach the timeline with their depth and nesting in time; threads alive together under one name get labels of their own, ones after another share a lane.
+    #[test]
+    fn the_timeline_keeps_each_threads_spans_with_their_depth_and_place_in_time() {
+        use super::timeline;
+        use std::sync::{Arc, Barrier};
+        use std::time::{Duration, Instant};
+        let _switch = spans_switch();
+        assert!(timeline::start(Instant::now()));
+        assert!(
+            !timeline::start(Instant::now()),
+            "the process has one timeline"
+        );
+        let spawn = |name: &str, alive_with: Option<Arc<Barrier>>| {
+            std::thread::Builder::new()
+                .name(name.into())
+                .spawn(move || {
+                    super::time("outer", || {
+                        std::thread::sleep(Duration::from_millis(4));
+                        super::time("inner", || std::thread::sleep(Duration::from_millis(3)));
+                    });
+                    if let Some(barrier) = alive_with {
+                        barrier.wait();
+                    }
+                })
+                .unwrap()
+        };
+        spawn("tl-solo", None).join().unwrap();
+        let together = Arc::new(Barrier::new(2));
+        let twins = [
+            spawn("tl-twin", Some(together.clone())),
+            spawn("tl-twin", Some(together)),
+        ];
+        for twin in twins {
+            twin.join().unwrap();
+        }
+        spawn("tl-seq", None).join().unwrap();
+        spawn("tl-seq", None).join().unwrap();
+        let mut threads = timeline::finish();
+        threads.retain(|t| t.thread.starts_with("tl-"));
+        threads.sort_by(|a, b| a.thread.cmp(&b.thread));
+        let labels: Vec<_> = threads.iter().map(|t| t.thread.as_str()).collect();
+        assert_eq!(labels, ["tl-seq", "tl-solo", "tl-twin", "tl-twin #2"]);
+        for thread in &threads {
+            let runs = if thread.thread == "tl-seq" { 2 } else { 1 };
+            assert_eq!(thread.events.len(), 2 * runs, "{thread:?}");
+            for pair in thread.events.chunks(2) {
+                let [inner, outer] = pair else { unreachable!() };
+                assert_eq!((inner.name, inner.depth), ("inner", 1));
+                assert_eq!((outer.name, outer.depth), ("outer", 0));
+                assert!(
+                    inner.dur_us >= 3_000 && outer.dur_us >= 7_000,
+                    "{inner:?} {outer:?}"
+                );
+                assert!(inner.start_us >= outer.start_us + 4_000);
+                assert!(
+                    inner.start_us + u64::from(inner.dur_us)
+                        <= outer.start_us + u64::from(outer.dur_us)
+                );
+            }
+        }
+        let seq = threads.iter().find(|t| t.thread == "tl-seq").unwrap();
+        assert!(seq.events[2].start_us >= seq.events[1].start_us + u64::from(seq.events[1].dur_us));
+
+        spawn("tl-after", None).join().unwrap();
+        assert!(
+            timeline::drain().is_empty(),
+            "a stopped timeline records nothing"
+        );
+    }
 }
@@ -478,9 +478,9 @@ impl Sprites {
        let metadata = match horizon_core::prepared_files::read_to_string(
            &path.with_extension("png.mcmeta"),
        ) {
-            Ok(text) => Some(serde_json::from_str::<
+            Ok(text) => Some(crate::packs::first_json::<
                BTreeMap<String, Box<serde_json::value::RawValue>>,
-            >(&text)?),
+            >(text.as_bytes())?),
            Err(error) if error.kind() == std::io::ErrorKind::NotFound => None,
            Err(error) => return Err(error.into()),
        };
@@ -589,9 +589,9 @@ impl Sprites {
        let metadata = match horizon_core::prepared_files::read_to_string(
            &path.with_extension("png.mcmeta"),
        ) {
-            Ok(text) => Some(serde_json::from_str::<
+            Ok(text) => Some(crate::packs::first_json::<
                BTreeMap<String, Box<serde_json::value::RawValue>>,
-            >(&text)?),
+            >(text.as_bytes())?),
            Err(error) if error.kind() == std::io::ErrorKind::NotFound => None,
            Err(error) => return Err(error.into()),
        };
@@ -28,37 +28,7 @@ pub const IDLE_RELEASE: std::time::Duration = std::time::Duration::from_secs(5);
 /// Worker CPU time and job counts by kind, for benchmarks
 /// (`examples/gen_light_bench.rs`). Off unless enabled: a relaxed load per
 /// job then.
-pub mod job_stats {
-    use std::sync::atomic::{AtomicBool, AtomicU64, Ordering};
-    pub const KINDS: [&str; 7] = [
-        "load", "generate", "decorate", "finish", "light", "mesh", "other",
-    ];
-    static ENABLED: AtomicBool = AtomicBool::new(false);
-    static NANOS: [AtomicU64; 7] = [const { AtomicU64::new(0) }; 7];
-    static COUNT: [AtomicU64; 7] = [const { AtomicU64::new(0) }; 7];
-    pub fn enable(on: bool) {
-        ENABLED.store(on, Ordering::Relaxed);
-    }
-    pub(super) fn enabled() -> bool {
-        ENABLED.load(Ordering::Relaxed)
-    }
-    pub(super) fn add(kind: usize, nanos: u64) {
-        NANOS[kind].fetch_add(nanos, Ordering::Relaxed);
-        COUNT[kind].fetch_add(1, Ordering::Relaxed);
-    }
-    /// (kind, nanoseconds, count) since the last call; resets them.
-    pub fn take() -> Vec<(&'static str, u64, u64)> {
-        (0..KINDS.len())
-            .map(|i| {
-                (
-                    KINDS[i],
-                    NANOS[i].swap(0, Ordering::Relaxed),
-                    COUNT[i].swap(0, Ordering::Relaxed),
-                )
-            })
-            .collect()
-    }
-}
+pub mod job_stats;
 /// A chunk under generation, opaque to the streamer.
 pub type Proto = Box<dyn std::any::Any + Send>;
 /// Chunk generation in vanilla's stages: a neighbour-independent proto chunk
@@ -1070,6 +1040,8 @@ pub struct WorkerContext {
    pub light: Arc<LightTables>,
 }
 mod bounded;
+mod queue_census;
+pub use queue_census::QueueCensus;
 mod forced_cover;
 mod forced_ring;
 mod relight_now;
@@ -1466,7 +1438,7 @@ impl Streaming {
        let entities = std::mem::take(&mut chunk.entities);
        world.entities_pending.insert((chunk.x, chunk.z));
        if !entities.is_empty() {
-            world.loaded_entities.push(((chunk.x, chunk.z), entities));
+            world.queue_entity_nbt((chunk.x, chunk.z), entities);
        }
        self.generated_total += 1;
        // A chunk saved with its light needs no light job; its unlit
@@ -1683,6 +1655,7 @@ impl Streaming {
        &mut self,
        world: &mut World,
    ) -> (Vec<((i32, i32, i32), SectionMesh)>, Vec<Arc<Chunk>>) {
+        let mut hz_laps = crate::spans::laps();
        let mut uploads = Vec::new();
        if self.paused {
            return (uploads, Vec::new());
@@ -1708,6 +1681,7 @@ impl Streaming {
        self.scan_age = if sweep { 0 } else { self.scan_age + 1 };
        self.requeue();
        self.relight_edits(world);
+        hz_laps.lap("st_relight_edits");
        let deferred = std::mem::take(&mut self.deferred);
        let received = self.shared.done.take();
        // Meshes made stale meanwhile, freed with the uploaded ones (`free`).
@@ -1757,6 +1731,7 @@ impl Streaming {
                }
            }
        }
+        hz_laps.lap("st_results");
        self.free(stale);
        let mut removed = Vec::new();
        if sweep {
@@ -1804,10 +1779,7 @@ impl Streaming {
                                > r4 * r4)
                        && !ranges.in_extra(x, z, 4)
                        && !ranges.in_band(x, z, 4)
-                        && !ranges.forced_chunks().any(|f| {
-                            (x - f.0).abs() <= FORCED_TERRAIN_RING
-                                && (z - f.1).abs() <= FORCED_TERRAIN_RING
-                        })
+                        && !ranges.forced_within(x, z, FORCED_TERRAIN_RING)
                })
                .map(|(k, _)| *k)
                .collect();
@@ -1827,6 +1799,7 @@ impl Streaming {
            }
            self.save_checked_out(written);
        }
+        hz_laps.lap("st_sweep");
        let (protos, finishing) = (&self.protos, &self.finishing);
        self.decorated.retain(|k| {
            protos.contains_key(k) || finishing.contains(k) || world.chunks.contains_key(k)
@@ -1858,6 +1831,7 @@ impl Streaming {
                self.submit(Some((x, z)), 0, Job::Finish(proto));
            }
        }
+        hz_laps.lap("st_finalize");
        // Decorate chunks whose 3x3 proto neighbourhood is available, in
        // vanilla's order: decoration is order dependent where write regions
        // overlap (see `DecorationOrder`).
@@ -1983,7 +1957,9 @@ impl Streaming {
                self.submit(Some((x, z)), 1, Job::Decorate(x, z, region, finals));
            }
        }
+        hz_laps.lap("st_decorate");
        self.schedule_generation(world, workers);
+        hz_laps.lap("st_generate");
        // Lighting once all neighbours exist, nearest first and only as
        // much of it as the workers can chew. Vanilla's light engine also
        // hands a bounded queue to its workers and reschedules what did
@@ -2019,6 +1995,7 @@ impl Streaming {
                Job::Light(x, z, region, self.sequence, self.sky_light),
            );
        }
+        hz_laps.lap("st_light");
        // A server draws nothing: its sections are never meshed.
        if !self.mesh {
            world.dirty_sections.clear();
@@ -2059,6 +2036,7 @@ impl Streaming {
                !back
            });
        }
+        hz_laps.lap("st_waiting");
        // Column by column: the checks below hold for all of a column's
        // sections, and columns waiting for light cost one look per frame.
        columns.extend(world.dirty_sections.columns());
@@ -2091,6 +2069,7 @@ impl Streaming {
            }
            candidates.push((self.distance(x, z), x, z, sections));
        }
+        hz_laps.lap("st_candidates");
        // Nearest first, and only as many sections as the workers can chew.
        // Every ready column used to be submitted at once, so at a wide
        // render distance the queue — and `meshing`, and each job's 3x3
@@ -6,16 +6,20 @@ use std::collections::HashSet;

 /// `Streaming::forced` and `mod_forced` as the Chebyshev distance from each column within
 /// `REACH` of one to the nearest: `Ranges::in_main_range` answers by one lookup instead of going
-/// through every forced chunk (it is asked for every column, several times a tick).
+/// through every forced chunk (it is asked for every column, several times a tick). Past `MOST`
+/// forced chunks, and for a reach past `REACH`, their tiles answer.
 pub(super) struct ForcedCover {
    forced: HashSet<(i32, i32)>,
    mod_forced: HashSet<(i32, i32)>,
-    near: FxHashMap<(i32, i32), u8>,
+    /// None past `MOST`.
+    near: Option<FxHashMap<(i32, i32), u8>>,
+    tiles: Tiles,
 }
 impl ForcedCover {
    /// The widest ring `in_main_range` asks of a forced chunk (margins 1 to 4).
    const REACH: i32 = FORCED_TERRAIN_RING + 1;
-    /// Past this many forced chunks the cover is not made: the scan answers.
+    /// Past this many forced chunks the distance map is not made (it holds up to
+    /// `(2 * REACH + 1)^2` entries a forced chunk): the tiles answer.
    const MOST: usize = 4096;
    pub(super) fn refresh(
        cover: &mut Option<Self>,
@@ -28,33 +32,85 @@ impl ForcedCover {
        {
            return;
        }
-        if forced.len() + mod_forced.len() > Self::MOST {
-            *cover = None;
-            return;
-        }
-        let mut near = FxHashMap::default();
-        for &(fx, fz) in forced.iter().chain(mod_forced) {
-            for dx in -Self::REACH..=Self::REACH {
-                for dz in -Self::REACH..=Self::REACH {
-                    let d = dx.abs().max(dz.abs()) as u8;
-                    near.entry((fx + dx, fz + dz))
-                        .and_modify(|e: &mut u8| *e = (*e).min(d))
-                        .or_insert(d);
+        let near = (forced.len() + mod_forced.len() <= Self::MOST).then(|| {
+            let mut near = FxHashMap::default();
+            for &(fx, fz) in forced.iter().chain(mod_forced) {
+                for dx in -Self::REACH..=Self::REACH {
+                    for dz in -Self::REACH..=Self::REACH {
+                        let d = dx.abs().max(dz.abs()) as u8;
+                        near.entry((fx + dx, fz + dz))
+                            .and_modify(|e: &mut u8| *e = (*e).min(d))
+                            .or_insert(d);
+                    }
                }
            }
-        }
+            near
+        });
        *cover = Some(Self {
            forced: forced.clone(),
            mod_forced: mod_forced.clone(),
            near,
+            tiles: Tiles::new(forced.iter().chain(mod_forced)),
        });
    }
-    /// Whether a forced chunk lies within `reach` of `(x, z)`, or `None` past `REACH`.
-    pub(super) fn within(&self, x: i32, z: i32, reach: i32) -> Option<bool> {
-        (reach <= Self::REACH).then(|| {
-            self.near
-                .get(&(x, z))
-                .is_some_and(|&d| i32::from(d) <= reach)
+    /// Whether a forced chunk lies within `reach` of `(x, z)` (Chebyshev).
+    pub(super) fn within(&self, x: i32, z: i32, reach: i32) -> bool {
+        match &self.near {
+            Some(near) if reach <= Self::REACH => {
+                near.get(&(x, z)).is_some_and(|&d| i32::from(d) <= reach)
+            }
+            _ => self.tiles.within(x, z, reach),
+        }
+    }
+}
+
+/// The forced chunks as bits, 8 by 8 columns a word: `(x, z)`'s bit is `(z & 7) * 8 + (x & 7)`
+/// of the word at `(x >> 3, z >> 3)`. A question reads only the words its square overlaps (four
+/// at most for a reach up to 4, nine up to 8), however many chunks are forced. It holds one word
+/// and its key for each tile with a forced chunk in it.
+struct Tiles(FxHashMap<(i32, i32), u64>);
+impl Tiles {
+    fn new<'a>(chunks: impl Iterator<Item = &'a (i32, i32)>) -> Self {
+        let mut tiles = FxHashMap::default();
+        for &(x, z) in chunks {
+            *tiles.entry((x >> 3, z >> 3)).or_insert(0) |= 1u64 << ((z & 7) * 8 + (x & 7));
+        }
+        Self(tiles)
+    }
+    /// Whether a chunk's bit is set within `reach` of `(x, z)` (Chebyshev).
+    fn within(&self, x: i32, z: i32, reach: i32) -> bool {
+        if reach < 0 {
+            return false;
+        }
+        let (x0, x1) = (x.saturating_sub(reach), x.saturating_add(reach));
+        let (z0, z1) = (z.saturating_sub(reach), z.saturating_add(reach));
+        // The square's bits in the tile at (tx, tz).
+        let hit = |(tx, tz): (i32, i32), bits: u64| {
+            let (bx, bz) = (i64::from(tx) * 8, i64::from(tz) * 8);
+            let lx0 = (i64::from(x0) - bx).max(0);
+            let lx1 = (i64::from(x1) - bx).min(7);
+            let lz0 = (i64::from(z0) - bz).max(0);
+            let lz1 = (i64::from(z1) - bz).min(7);
+            if lx0 > lx1 || lz0 > lz1 {
+                return false;
+            }
+            // Columns lx0..=lx1 of one row, copied to every row, then rows lz0..=lz1.
+            let row = (0xFFu64 >> (7 - (lx1 - lx0))) << lx0;
+            let rows = (u64::MAX >> (8 * (7 - (lz1 - lz0)))) << (8 * lz0);
+            bits & row.wrapping_mul(0x0101_0101_0101_0101) & rows != 0
+        };
+        let (tx0, tx1, tz0, tz1) = (x0 >> 3, x1 >> 3, z0 >> 3, z1 >> 3);
+        let overlapped = (i64::from(tx1 - tx0) + 1) * (i64::from(tz1 - tz0) + 1);
+        // A square wider than the tiles held (a far reach): go through the tiles instead.
+        if overlapped > self.0.len() as i64 {
+            return self.0.iter().any(|(&t, &bits)| hit(t, bits));
+        }
+        (tz0..=tz1).any(|tz| {
+            (tx0..=tx1).any(|tx| {
+                self.0
+                    .get(&(tx, tz))
+                    .is_some_and(|&bits| hit((tx, tz), bits))
+            })
        })
    }
 }
@@ -83,8 +139,13 @@ impl Ranges<'_> {
            3 => FORCED_TERRAIN_RING,
            _ => margin + 1,
        };
-        if let Some(hit) = self.forced_cover.and_then(|c| c.within(x, z, reach)) {
-            return hit;
+        self.forced_within(x, z, reach)
+    }
+    /// Whether a forced chunk lies within `reach` of `(x, z)` (Chebyshev): from the cover while
+    /// `update` runs, else by a scan of every forced chunk.
+    pub(super) fn forced_within(&self, x: i32, z: i32, reach: i32) -> bool {
+        if let Some(cover) = self.forced_cover {
+            return cover.within(x, z, reach);
        }
        self.forced_chunks()
            .any(|f| (x - f.0).abs() <= reach && (z - f.1).abs() <= reach)
@@ -152,14 +213,194 @@ mod tests {
        }
    }

-    /// Too many forced chunks for a map: none is made, and the scan answers.
+    /// Too many forced chunks for a map: none is made, and the tiles answer.
    #[test]
    fn past_the_most_no_map_is_made() {
        let forced: HashSet<(i32, i32)> = (0..=ForcedCover::MOST as i32).map(|x| (x, 0)).collect();
        let mut cover = None;
        ForcedCover::refresh(&mut cover, &HashSet::new(), &HashSet::from([(0, 0)]));
-        assert!(cover.is_some());
+        assert!(cover.as_ref().is_some_and(|c| c.near.is_some()));
        ForcedCover::refresh(&mut cover, &forced, &HashSet::new());
-        assert!(cover.is_none());
+        let made = cover
+            .as_ref()
+            .expect("a cover is made however many are forced");
+        assert!(made.near.is_none());
+        assert!(made.within(-3, 3, 3) && !made.within(-3, 4, 3));
+    }
+
+    /// Forced chunks in a disc, in clusters and scattered: `n` of them (the clusters a few more).
+    fn sets(seed: &mut u64, n: usize) -> [HashSet<(i32, i32)>; 3] {
+        let r = (n as f64 / std::f64::consts::PI).sqrt().ceil() as i32;
+        let disc: HashSet<_> = (-r..=r)
+            .flat_map(|z| (-r..=r).map(move |x| (x, z)))
+            .filter(|&(x, z)| x * x + z * z <= r * r)
+            .take(n)
+            .collect();
+        let mut clusters = HashSet::new();
+        while clusters.len() < n {
+            let (cx, cz) = chunks(seed, 1, 400).into_iter().next().unwrap();
+            clusters.extend(
+                chunks(seed, 64, 6)
+                    .into_iter()
+                    .map(|(x, z)| (cx + x, cz + z)),
+            );
+        }
+        let spread = (n as f64).sqrt() as i32 * 6;
+        let mut scattered = HashSet::new();
+        while scattered.len() < n {
+            scattered.extend(chunks(seed, n - scattered.len(), spread));
+        }
+        [disc, clusters, scattered]
+    }
+
+    /// Well past `MOST`, and either side of it, the cover answers every reach as the scan of
+    /// every forced chunk does: around forced chunks, between them, on tile edges and far off,
+    /// with some held by both a `/forceload` and a mod's ticket.
+    #[test]
+    fn past_the_most_the_tiles_answer_as_the_scan() {
+        let mut seed = 0x9E37_79B9_7F4A_7C15u64;
+        let m = ForcedCover::MOST;
+        // Some held both ways past the boundary, none at it (a chunk held both ways counts twice
+        // towards `MOST`, as `refresh` counts them).
+        for (n, both) in [(m, false), (m + 1, false), (6000, true), (20_000, true)] {
+            for (kind, all) in sets(&mut seed, n).into_iter().enumerate() {
+                // Every third chunk a mod's ticket; with `both`, every fifth held both ways.
+                let (mut forced, mut mod_forced) = (HashSet::new(), HashSet::new());
+                for (i, &c) in all.iter().enumerate() {
+                    if i % 3 == 0 || (both && i % 5 == 0) {
+                        mod_forced.insert(c);
+                    }
+                    if i % 3 != 0 {
+                        forced.insert(c);
+                    }
+                }
+                let mut cover = None;
+                ForcedCover::refresh(&mut cover, &forced, &mod_forced);
+                let made = cover.as_ref().unwrap();
+                let held = forced.len() + mod_forced.len();
+                assert_eq!(made.near.is_some(), held <= m);
+                let ranges = |forced_cover| Ranges {
+                    center: (10_000_000, 10_000_000),
+                    radius: 2,
+                    extra: &[],
+                    forced: &forced,
+                    mod_forced: &mod_forced,
+                    cover: None,
+                    forced_cover,
+                    band: None,
+                };
+                let (scan, map) = (ranges(None), ranges(Some(made)));
+                // The scan goes through every forced chunk: fewer columns for more of them.
+                let near: Vec<_> = all.iter().step_by(all.len() / 40).copied().collect();
+                let offsets = chunks(&mut seed, 6, 12);
+                let far = chunks(&mut seed, 12, 3000);
+                let columns = near
+                    .iter()
+                    .flat_map(|&(x, z)| offsets.iter().map(move |&(dx, dz)| (x + dx, z + dz)))
+                    .chain(far);
+                for (x, z) in columns {
+                    for reach in [-1, 0, 1, 2, 3, 4, 5, 6, 8, 11, 40] {
+                        assert_eq!(
+                            map.forced_within(x, z, reach),
+                            scan.forced_within(x, z, reach),
+                            "{n} forced, set {kind}, ({x}, {z}) reach {reach}"
+                        );
+                    }
+                    for margin in 1..=4 {
+                        assert_eq!(
+                            map.in_main_range(x, z, margin),
+                            scan.in_main_range(x, z, margin)
+                        );
+                    }
+                }
+            }
+        }
+    }
+
+    /// Each tile's bits answer for every square that overlaps it in part: corners, edges and
+    /// across negative coordinates.
+    #[test]
+    fn a_tiles_edges_answer_as_the_scan() {
+        let mut seed = 0xD1B5_4A32_D192_ED03u64;
+        for _ in 0..200 {
+            let set = chunks(&mut seed, 3, 9);
+            let tiles = Tiles::new(set.iter());
+            for z in -14..=14 {
+                for x in -14..=14 {
+                    for reach in 0..=9 {
+                        let scan = set
+                            .iter()
+                            .any(|f| (x - f.0).abs() <= reach && (z - f.1).abs() <= reach);
+                        assert_eq!(
+                            tiles.within(x, z, reach),
+                            scan,
+                            "{set:?} ({x}, {z}) {reach}"
+                        );
+                    }
+                }
+            }
+        }
+    }
+
+    /// What a question and the cover cost by how many chunks are forced: run with
+    /// `cargo test --release -p horizon-client-render forced_cover_cost -- --ignored --nocapture`.
+    #[test]
+    #[ignore = "timings; run with --release --ignored --nocapture"]
+    fn forced_cover_cost() {
+        let mut seed = 0x2545_F491_4F6C_DD1Du64;
+        for n in [1000, 4000, 4097, 6000, 20_000] {
+            for (kind, forced) in sets(&mut seed, n).into_iter().enumerate() {
+                let none = HashSet::new();
+                let started = std::time::Instant::now();
+                let mut cover = None;
+                ForcedCover::refresh(&mut cover, &forced, &none);
+                let made_in = started.elapsed();
+                let made = cover.as_ref().unwrap();
+                let ranges = |forced_cover| Ranges {
+                    center: (10_000_000, 10_000_000),
+                    radius: 2,
+                    extra: &[],
+                    forced: &forced,
+                    mod_forced: &none,
+                    cover: None,
+                    forced_cover,
+                    band: None,
+                };
+                let spread = forced
+                    .iter()
+                    .map(|f| f.0.abs().max(f.1.abs()))
+                    .max()
+                    .unwrap()
+                    + 20;
+                let columns = chunks(&mut seed, 200_000, spread);
+                let time = |r: &Ranges, take: usize| {
+                    let started = std::time::Instant::now();
+                    let mut hits = 0usize;
+                    for &(x, z) in columns.iter().take(take) {
+                        for margin in 1..=4 {
+                            hits += usize::from(r.in_main_range(x, z, margin));
+                        }
+                    }
+                    (
+                        started.elapsed().as_nanos() as f64 / (take * 4) as f64,
+                        hits,
+                    )
+                };
+                let (cover_ns, _) = time(&ranges(Some(made)), columns.len());
+                let (scan_ns, _) = time(&ranges(None), 2000);
+                let bytes = made.tiles.0.capacity() * (16 + 1)
+                    + made.near.as_ref().map_or(0, |m| m.capacity() * (12 + 1));
+                println!(
+                    "{n:>6} forced ({}): cover {cover_ns:6.1} ns a question, scan {scan_ns:8.0} ns; \
+                     made in {made_in:?}, {} tiles, distance map {}, ~{} KiB",
+                    ["disc", "clusters", "scattered"][kind],
+                    made.tiles.0.len(),
+                    made.near
+                        .as_ref()
+                        .map_or("none".to_string(), |m| m.len().to_string()),
+                    bytes / 1024
+                );
+            }
+        }
    }
 }
@@ -0,0 +1,29 @@
+use std::sync::atomic::{AtomicBool, AtomicU64, Ordering};
+pub const KINDS: [&str; 7] = [
+    "load", "generate", "decorate", "finish", "light", "mesh", "other",
+];
+static ENABLED: AtomicBool = AtomicBool::new(false);
+static NANOS: [AtomicU64; 7] = [const { AtomicU64::new(0) }; 7];
+static COUNT: [AtomicU64; 7] = [const { AtomicU64::new(0) }; 7];
+pub fn enable(on: bool) {
+    ENABLED.store(on, Ordering::Relaxed);
+}
+pub(super) fn enabled() -> bool {
+    ENABLED.load(Ordering::Relaxed)
+}
+pub(super) fn add(kind: usize, nanos: u64) {
+    NANOS[kind].fetch_add(nanos, Ordering::Relaxed);
+    COUNT[kind].fetch_add(1, Ordering::Relaxed);
+}
+/// (kind, nanoseconds, count) since the last call; resets them.
+pub fn take() -> Vec<(&'static str, u64, u64)> {
+    (0..KINDS.len())
+        .map(|i| {
+            (
+                KINDS[i],
+                NANOS[i].swap(0, Ordering::Relaxed),
+                COUNT[i].swap(0, Ordering::Relaxed),
+            )
+        })
+        .collect()
+}
@@ -0,0 +1,39 @@
+//! What the streamer's queues hold, for `horizon-ctl memory` and captures.
+use super::{Queued, Streaming};
+
+/// What the streamer's work queues hold, each as (entries, estimated bytes).
+#[derive(Debug, Default)]
+pub struct QueueCensus {
+    /// Jobs queued and chunks generating.
+    pub generation: (usize, usize),
+    /// Chunks being lit and the edit log their jobs replay.
+    pub light: (usize, usize),
+}
+
+impl Streaming {
+    /// The queues' lengths and the bytes of their tables, from capacities. For `horizon-ctl memory`.
+    pub fn queue_census(&self) -> QueueCensus {
+        use std::mem::size_of;
+        let table = |capacity: usize, entry: usize| capacity * (entry + 1);
+        let queued = {
+            let queue = self.shared.queue.lock().unwrap();
+            (queue.len(), queue.capacity() * size_of::<Queued>())
+        };
+        QueueCensus {
+            generation: (
+                queued.0 + self.generating.len(),
+                queued.1 + table(self.generating.capacity(), size_of::<(i32, i32)>()),
+            ),
+            light: (
+                self.lighting.len(),
+                table(self.lighting.capacity(), size_of::<((i32, i32), u64)>())
+                    + table(
+                        self.light_snapshots.capacity(),
+                        size_of::<((i32, i32), u64)>(),
+                    )
+                    + self.light_log.capacity() * size_of::<(u64, (i32, i32, i32))>()
+                    + self.light_scratch.capacity() * size_of::<(i64, i32, i32)>(),
+            ),
+        }
+    }
+}
@@ -43,7 +43,7 @@ struct Globals {
    // w: apply the no-pack HDR gain; HDR_WRITE_LIGHT independently keeps float alpha as coverage.
    hdr_light: vec4<f32>,
    hdr_settings: vec4<f32>,
-    hdr_shares: vec4<f32>,
+    hdr_gains: vec4<f32>,
 }
@group(0) @binding(0) var<uniform> globals: Globals;
@group(0) @binding(1) var sprites: texture_2d_array<f32>;
@@ -788,7 +788,7 @@ fn solid_finish(in: TerrainOut, texel: vec4<f32>, color: vec4<f32>) -> vec4<f32>
 fn solid_light(finished: vec4<f32>) -> vec4<f32> {
    if HDR_WRITE_LIGHT {
        if globals.hdr_light.w != 0.0 {
-            return vec4(hdr_written(finished.rgb, finished.a, globals.hdr_settings, globals.hdr_shares), 1.0);
+            return vec4(hdr_written(finished.rgb, finished.a, globals.hdr_settings, globals.hdr_gains), 1.0);
        }
        return frame_stored(vec4(finished.rgb, 1.0));
    }
@@ -870,7 +870,7 @@ fn solid_finish_at(in: TerrainOut, texel: vec4<f32>, color: vec4<f32>, du: vec2<
        let fogged = max(linear_fog(in.spherical, globals.fog.x, globals.fog.y),
            linear_fog(in.cylindrical, globals.fog.z, globals.fog.w)) * globals.fog_color.a;
        let mark = hdr_scene_alpha(mix(hdr_scene(in.scene.x, in.scene.y, hdr_facing()), globals.hdr_light.y, fogged));
-        return vec4(hdr_written(finished.rgb, mark, globals.hdr_settings, globals.hdr_shares), finished.a);
+        return vec4(hdr_written(finished.rgb, mark, globals.hdr_settings, globals.hdr_gains), finished.a);
    }
    return frame_stored(finished);
 }
@@ -1076,7 +1076,7 @@ fn sky_finished(color: vec3<f32>) -> vec4<f32> {
    let mark = 1.0 - 0.24 * globals.hdr_light.y;
    if HDR_WRITE_LIGHT {
        if globals.hdr_light.w != 0.0 {
-            return vec4(hdr_written(color, mark, globals.hdr_settings, globals.hdr_shares), 1.0);
+            return vec4(hdr_written(color, mark, globals.hdr_settings, globals.hdr_gains), 1.0);
        }
        return frame_stored(vec4(color, 1.0));
    }
@@ -11,6 +11,7 @@
 //! D-pad, a button, or a look gesture on the world) and keeps it until it
 //! lifts, so moving, looking and pressing never take each other's fingers.
 pub mod aim;
+mod draw;
 pub mod layout;
 pub use aim::{
    attack_indicator, camera_delta, hotbar_slot, item_places_entity_on_tap, item_uses_on_tap,
@@ -81,6 +82,11 @@ pub struct TouchControls {
    pub vertical_movement: bool,
    pub swimming: bool,
    pub mounted: bool,
+    /// The player is sneaking: the sneak button shows held.
+    pub sneaking: bool,
+    /// How far the block under a world hold is broken (0..1), drawn in the
+    /// touch marker.
+    pub break_progress: f32,
    /// A long hold on the world uses the held item instead of mining. Read when
    /// a finger lands, so a change mid-hold (the last apple eaten) can't turn
    /// eating into mining.
@@ -0,0 +1,465 @@
+// Adapted from Starling (https://github.com/starling-client/starling, `android` branch at
+// 150a414b09a1, `crates/horizon-client-render/src/touch.rs`), written by Vasysik and the
+// Starling contributors. Copyright (c) 2026 Ludovic Marie and the Horizon contributors, under the
+// same MIT license as Horizon (LICENSE at the repository root).
+
+//! Drawing the touch controls on the HUD, in GUI pixels. Buttons use the
+//! resource pack's own button sprite (`widget/button`, highlighted while held)
+//! with a short label; the joystick, the D-pad and the tap marker are plain
+//! shapes. No art of its own ships with the game.
+use super::{Control, Mode, Placement, Role, TouchControls, layout};
+use crate::gamepad::{Button, PadState};
+use crate::hud::{HudAtlas, HudBatch, rgba};
+use crate::lang;
+
+const BUTTON: &str = "gui/sprites/widget/button";
+const BUTTON_HELD: &str = "gui/sprites/widget/button_highlighted";
+
+impl TouchControls {
+    /// Draws every visible control, then the tap marker in the tap schemes.
+    pub fn draw(&self, b: &mut HudBatch, a: &HudAtlas) {
+        let state = self.state();
+        for control in Control::ALL {
+            if !self.visible(control) {
+                continue;
+            }
+            let p = self.placement(control);
+            let color = rgba(255, 255, 255, alpha(p.opacity));
+            if control == Control::Move {
+                self.draw_move(b, a, p, &state, color);
+                continue;
+            }
+            let bounds = square(b, p.center, p.size);
+            let rect = p.rect(self.aspect());
+            let pressed = self.held(control, &state)
+                || self
+                    .fingers
+                    .values()
+                    .any(|(_, point)| layout::contains(rect, *point));
+            button(b, a, bounds, &self.label(control), pressed, color);
+        }
+        if let Some(point) = self.pointer() {
+            let center = [point[0] * b.width, point[1] * b.height];
+            let radius = self.settings.circle_size / 2.0;
+            ring(b, a, center, radius + 0.7, rgba(0, 0, 0, 110));
+            ring(b, a, center, radius, rgba(255, 255, 255, 210));
+            // Mining fills the circle outwards from its centre.
+            let inner = mining_radius(radius, self.break_progress);
+            if inner > 0.0 {
+                disc(b, a, center, inner, rgba(255, 255, 255, 90));
+                ring(b, a, center, inner, rgba(255, 255, 255, 220));
+            }
+        }
+    }
+
+    /// Whether a control shows as held: its button is down, or it latched.
+    fn held(&self, control: Control, state: &PadState) -> bool {
+        if control == Control::Sneak && self.sneaking {
+            return true;
+        }
+        Self::button(control).is_some_and(|button| match button {
+            Button::LeftTrigger => state.triggers[0] > 0.0,
+            Button::RightTrigger => state.triggers[1] > 0.0,
+            _ => state.held(button),
+        })
+    }
+
+    /// The label a control's button shows, in the player's language. Key
+    /// names and symbols ("F3", "II") read the same in every language.
+    fn label(&self, control: Control) -> String {
+        let vertical = self.swimming || self.vertical_movement;
+        let key = match control {
+            Control::Move => return String::new(),
+            Control::Pause => return "II".to_owned(),
+            Control::Inventory => return "...".to_owned(),
+            Control::Debug => return "F3".to_owned(),
+            Control::Perspective => return "F5".to_owned(),
+            Control::Sprint => "horizon.touch.sprint",
+            Control::Jump if vertical => "horizon.touch.up",
+            Control::Jump => "horizon.touch.jump",
+            Control::Sneak if vertical => "horizon.touch.down",
+            Control::Sneak if self.mounted => "horizon.touch.dismount",
+            Control::Sneak => "horizon.touch.sneak",
+            Control::Attack => "horizon.touch.attack",
+            Control::Use => "horizon.touch.use",
+            Control::Chat => "horizon.touch.chat",
+            Control::Settings => "horizon.touch.settings",
+            Control::Offhand => "horizon.touch.swap",
+            Control::Shield => "horizon.touch.shield",
+        };
+        lang::get(key)
+    }
+
+    /// The joystick (a rim and a knob) or the D-pad (four arrow buttons).
+    fn draw_move(
+        &self,
+        b: &mut HudBatch,
+        a: &HudAtlas,
+        p: Placement,
+        state: &PadState,
+        color: u32,
+    ) {
+        let anchor = self.fingers.values().find_map(|(role, _)| match role {
+            Role::Move(anchor) => Some(*anchor),
+            _ => None,
+        });
+        let center = match anchor {
+            Some(anchor) if self.dynamic_joystick() => anchor,
+            // A dynamic joystick only shows while a finger holds it.
+            None if self.dynamic_joystick() => return,
+            _ => p.center,
+        };
+        let [x, y, size, _] = square(b, center, p.size);
+        if self.settings.mode == Mode::Dpad {
+            let cell = size / 3.0;
+            for ([dx, dy], label, pressed) in dpad(state.left) {
+                let bounds = [x + cell * dx, y + cell * dy, cell, cell];
+                button(b, a, bounds, label, pressed, color);
+            }
+            return;
+        }
+        let middle = [x + size / 2.0, y + size / 2.0];
+        let [r, g, blue, opacity] = color.to_le_bytes();
+        ring(b, a, middle, size / 2.0, color);
+        disc(b, a, middle, size / 2.0, rgba(0, 0, 0, opacity / 3));
+        let knob = knob(middle, state.left, size);
+        disc(b, a, knob, size * 0.17, rgba(r, g, blue, opacity / 2));
+        ring(b, a, knob, size * 0.17, color);
+    }
+}
+
+/// The D-pad's arrows: each one's cell in a 3x3 grid, its label and whether
+/// the stick (`left`, up positive) presses it.
+fn dpad(left: [f32; 2]) -> [([f32; 2], &'static str, bool); 4] {
+    [
+        ([1.0, 0.0], "^", left[1] > 0.2),
+        ([0.0, 1.0], "<", left[0] < -0.2),
+        ([2.0, 1.0], ">", left[0] > 0.2),
+        ([1.0, 2.0], "v", left[1] < -0.2),
+    ]
+}
+
+/// Where the joystick's knob sits: the stick is up positive, the screen down.
+fn knob(middle: [f32; 2], left: [f32; 2], size: f32) -> [f32; 2] {
+    [
+        middle[0] + left[0] * size / 4.0,
+        middle[1] - left[1] * size / 4.0,
+    ]
+}
+
+/// A placement's square in GUI pixels, `[x, y, size, size]`.
+fn square(b: &HudBatch, center: [f32; 2], size: f32) -> [f32; 4] {
+    let size = size * b.height;
+    [
+        center[0] * b.width - size / 2.0,
+        center[1] * b.height - size / 2.0,
+        size,
+        size,
+    ]
+}
+
+fn alpha(opacity: f32) -> u8 {
+    (opacity.clamp(0.0, 1.0) * 255.0).round() as u8
+}
+
+/// A labelled button: the pack's button sprite, or a plain frame when the
+/// pack has none. A held button darkens and its label drops a pixel.
+fn button(
+    b: &mut HudBatch,
+    a: &HudAtlas,
+    bounds: [f32; 4],
+    label: &str,
+    pressed: bool,
+    color: u32,
+) {
+    let [x, y, w, h] = bounds;
+    let [r, g, blue, opacity] = color.to_le_bytes();
+    if a.sprites.contains_key(BUTTON) {
+        let sprite = if pressed && a.sprites.contains_key(BUTTON_HELD) {
+            BUTTON_HELD
+        } else {
+            BUTTON
+        };
+        crate::ui::nine_slice(b, a, sprite, x, y, w, h, color);
+    } else {
+        let fill = if pressed { 150 } else { 90 };
+        b.fill(
+            a,
+            x,
+            y,
+            w,
+            h,
+            rgba(0, 0, 0, (u16::from(opacity) * fill / 255) as u8),
+        );
+        for edge in [
+            [x, y, w, 1.0],
+            [x, y + h - 1.0, w, 1.0],
+            [x, y, 1.0, h],
+            [x + w - 1.0, y, 1.0, h],
+        ] {
+            b.fill(a, edge[0], edge[1], edge[2], edge[3], color);
+        }
+    }
+    if label.is_empty() {
+        return;
+    }
+    let text = if pressed {
+        rgba(r / 2 + 127, g / 2 + 127, blue / 2, opacity)
+    } else {
+        color
+    };
+    let drop = if pressed { (h / 18.0).min(2.0) } else { 0.0 };
+    let width = HudBatch::text_width(a, label);
+    let start = b.vertices.len();
+    b.text(
+        a,
+        label,
+        x + (w - width) / 2.0,
+        y + (h - 8.0) / 2.0 + drop,
+        text,
+        true,
+    );
+    // Shrink a long label to fit, never grow a short one: the width leaves 3
+    // pixels each side, and the height cap keeps the 8-pixel line inside the
+    // same margin, never above full size.
+    let fit_width = (w - 6.0).max(1.0) / width.max(1.0);
+    let height_cap = ((h - 6.0).max(1.0) / 8.0).min(1.0);
+    let scale = fit_width.min(height_cap);
+    b.scale_since(start, x + w / 2.0, y + h / 2.0 + drop, scale, scale);
+}
+
+/// How far the mining disc reaches inside a marker of `radius`, by progress.
+fn mining_radius(radius: f32, progress: f32) -> f32 {
+    if progress.is_finite() {
+        (radius - 1.5).max(0.0) * progress.clamp(0.0, 1.0)
+    } else {
+        0.0
+    }
+}
+
+/// 65 points round the unit circle, the last one equal to the first.
+fn circle_points() -> &'static [[f32; 2]; 65] {
+    static POINTS: std::sync::OnceLock<[[f32; 2]; 65]> = std::sync::OnceLock::new();
+    POINTS.get_or_init(|| {
+        std::array::from_fn(|i| {
+            let angle = i as f32 / 64.0 * std::f32::consts::TAU;
+            [angle.cos(), angle.sin()]
+        })
+    })
+}
+
+/// A 1.4-pixel circle line, one quad per segment so nothing blends twice.
+fn ring(b: &mut HudBatch, a: &HudAtlas, center: [f32; 2], radius: f32, color: u32) {
+    let at = |p: [f32; 2], r: f32| [center[0] + p[0] * r, center[1] + p[1] * r];
+    let (outer, inner) = (radius + 0.7, (radius - 0.7).max(0.0));
+    for s in circle_points().windows(2) {
+        b.fill_quad(
+            a,
+            [
+                at(s[0], outer),
+                at(s[1], outer),
+                at(s[1], inner),
+                at(s[0], inner),
+            ],
+            color,
+        );
+    }
+}
+
+/// A filled circle.
+fn disc(b: &mut HudBatch, a: &HudAtlas, center: [f32; 2], radius: f32, color: u32) {
+    let at = |p: [f32; 2]| [center[0] + p[0] * radius, center[1] + p[1] * radius];
+    for s in circle_points().windows(2) {
+        b.fill_quad(a, [center, at(s[0]), at(s[1]), center], color);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn atlas() -> HudAtlas {
+        HudAtlas::build(std::path::Path::new("/nonexistent/horizon-touch-draw")).unwrap()
+    }
+
+    fn vertices(t: &TouchControls, a: &HudAtlas) -> usize {
+        let mut b = HudBatch::new([1920, 1080]);
+        t.draw(&mut b, a);
+        b.vertices.len()
+    }
+
+    #[test]
+    fn mining_disc_grows_outwards_within_the_marker() {
+        assert_eq!(mining_radius(16.0, 0.0), 0.0);
+        assert_eq!(mining_radius(16.0, 0.5), 7.25);
+        assert_eq!(mining_radius(16.0, 1.0), 14.5);
+        assert_eq!(mining_radius(16.0, 2.0), 14.5);
+        assert_eq!(mining_radius(16.0, -1.0), 0.0);
+        assert_eq!(mining_radius(16.0, f32::NAN), 0.0);
+    }
+
+    #[test]
+    fn hidden_controls_draw_nothing() {
+        let a = atlas();
+        let mut t = TouchControls::default();
+        assert!(vertices(&t, &a) > 0);
+        t.settings.button_visibility = [layout::HIDDEN; layout::CONTROLS];
+        assert_eq!(vertices(&t, &a), 0);
+    }
+
+    #[test]
+    fn a_dynamic_joystick_shows_only_while_held() {
+        let a = atlas();
+        let mut t = TouchControls::default();
+        t.settings.dynamic_joystick = true;
+        let idle = vertices(&t, &a);
+        t.update(1, [0.1, 0.6], true, false);
+        assert!(vertices(&t, &a) > idle);
+        t.update(1, [0.1, 0.6], false, true);
+        assert_eq!(vertices(&t, &a), idle);
+    }
+
+    #[test]
+    fn the_marker_shows_in_tap_schemes_and_fills_while_mining() {
+        let a = atlas();
+        let mut t = TouchControls::default();
+        let idle = vertices(&t, &a);
+        t.update(1, [0.6, 0.4], true, false);
+        assert_eq!(vertices(&t, &a), idle, "no marker with a crosshair");
+        t.clear();
+        t.settings.mode = Mode::Tap;
+        let idle = vertices(&t, &a);
+        t.update(1, [0.6, 0.4], true, false);
+        let marker = vertices(&t, &a);
+        assert!(marker > idle);
+        t.break_progress = 0.5;
+        assert!(vertices(&t, &a) > marker);
+    }
+
+    fn english<R>(f: impl FnOnce() -> R) -> R {
+        let (result, missed) = lang::scoped(lang::Language::load(&[], "en_us"), f);
+        assert!(missed.is_empty(), "no English text for {missed:?}");
+        result
+    }
+
+    #[test]
+    fn labels_and_held_buttons_follow_the_player() {
+        let mut t = TouchControls::default();
+        let all = |t: &TouchControls| english(|| Control::ALL.map(|c| t.label(c)));
+        assert_eq!(all(&t)[..3], ["", "Sprint", "Jump"]);
+        assert!(all(&t).iter().all(|l| !l.starts_with("horizon.")));
+        assert_eq!(t.label(Control::Debug), "F3");
+        t.swimming = true;
+        assert_eq!(english(|| t.label(Control::Jump)), "Up");
+        assert_eq!(english(|| t.label(Control::Sneak)), "Down");
+        t.swimming = false;
+        t.mounted = true;
+        assert_eq!(english(|| t.label(Control::Sneak)), "Dismount");
+        let state = t.state();
+        assert!(!t.held(Control::Sneak, &state));
+        t.sneaking = true;
+        assert!(t.held(Control::Sneak, &state));
+        t.update(1, t.placement(Control::Attack).center, true, false);
+        assert!(t.held(Control::Attack, &t.state()));
+        assert!(!t.held(Control::Use, &t.state()));
+    }
+
+    #[test]
+    fn colours_split_into_rgba_in_order() {
+        let half = rgba(255, 255, 255, alpha(0.5));
+        assert_eq!(half.to_le_bytes(), [255, 255, 255, 128]);
+        assert_eq!(rgba(10, 20, 30, 40).to_le_bytes(), [10, 20, 30, 40]);
+    }
+
+    /// One button drawn alone, as `button` draws it in `draw`.
+    fn one(a: &HudAtlas, bounds: [f32; 4], label: &str, pressed: bool) -> HudBatch {
+        let mut b = HudBatch::new([1920, 1080]);
+        button(&mut b, a, bounds, label, pressed, rgba(255, 255, 255, 128));
+        b
+    }
+
+    #[test]
+    fn a_held_button_uses_the_packs_highlighted_sprite() {
+        let mut a = atlas();
+        let rect = |u0: f32| crate::hud::Rect {
+            u0,
+            v0: 0.0,
+            u1: u0 + 0.1,
+            v1: 0.1,
+            w: 200,
+            h: 20,
+        };
+        a.sprites.insert(BUTTON.to_owned(), rect(0.2));
+        a.sprites.insert(BUTTON_HELD.to_owned(), rect(0.5));
+        let uses = |b: &HudBatch, u0: f32| {
+            b.vertices
+                .iter()
+                .any(|v| (u0..=u0 + 0.1).contains(&v.uv[0]) && v.uv[1] <= 0.1)
+        };
+        let idle = one(&a, [0.0, 0.0, 60.0, 20.0], "", false);
+        assert!(uses(&idle, 0.2) && !uses(&idle, 0.5));
+        let held = one(&a, [0.0, 0.0, 60.0, 20.0], "", true);
+        assert!(uses(&held, 0.5) && !uses(&held, 0.2));
+        assert!(
+            held.vertices
+                .iter()
+                .all(|v| v.color == rgba(255, 255, 255, 128))
+        );
+    }
+
+    #[test]
+    fn without_the_sprite_a_plain_frame_darkens_while_held() {
+        let a = atlas();
+        assert!(!a.sprites.contains_key(BUTTON));
+        let colours = |pressed| {
+            let b = one(&a, [10.0, 10.0, 60.0, 20.0], "", pressed);
+            b.vertices.iter().map(|v| v.color).collect::<Vec<_>>()
+        };
+        let (idle, held) = (colours(false), colours(true));
+        let mut fill = HudBatch::new([1920, 1080]);
+        fill.fill(&a, 0.0, 0.0, 1.0, 1.0, 0);
+        let quad = fill.vertices.len();
+        // The backdrop, then the four one-pixel edges in the button's colour.
+        assert_eq!(idle.len(), 5 * quad);
+        assert!(idle[..quad].iter().all(|&c| c == rgba(0, 0, 0, 45)));
+        assert!(held[..quad].iter().all(|&c| c == rgba(0, 0, 0, 75)));
+        assert!(idle[quad..].iter().all(|&c| c == rgba(255, 255, 255, 128)));
+    }
+
+    #[test]
+    fn a_long_label_shrinks_to_fit_and_a_short_one_keeps_its_size() {
+        let a = atlas();
+        let frame = one(&a, [0.0, 0.0, 40.0, 20.0], "", false).vertices.len();
+        let span = |label: &str| {
+            let b = one(&a, [0.0, 0.0, 40.0, 20.0], label, false);
+            assert!(b.vertices.len() > frame, "{label} drew no text");
+            let xs = b.vertices[frame..].iter().map(|v| v.pos[0]);
+            let (lo, hi) = xs.fold((f32::MAX, f32::MIN), |(lo, hi), x| (lo.min(x), hi.max(x)));
+            (lo, hi)
+        };
+        let long = "a label much wider than its button";
+        assert!(HudBatch::text_width(&a, long) > 40.0);
+        let (lo, hi) = span(long);
+        assert!(lo >= 3.0 - 1e-3 && hi <= 37.0 + 1e-3, "{lo}..{hi}");
+        let width = HudBatch::text_width(&a, "Up");
+        let (lo, hi) = span("Up");
+        assert!(hi - lo >= width - 1e-3, "{} < {width}", hi - lo);
+    }
+
+    #[test]
+    fn the_dpad_and_knob_follow_the_stick_up_positive() {
+        let only = |left: [f32; 2]| {
+            let on: Vec<_> = dpad(left).into_iter().filter(|p| p.2).collect();
+            assert_eq!(on.len(), 1, "{left:?}");
+            (on[0].0, on[0].1)
+        };
+        assert_eq!(only([0.0, 0.5]), ([1.0, 0.0], "^"));
+        assert_eq!(only([0.0, -0.5]), ([1.0, 2.0], "v"));
+        assert_eq!(only([-0.5, 0.0]), ([0.0, 1.0], "<"));
+        assert_eq!(only([0.5, 0.0]), ([2.0, 1.0], ">"));
+        assert!(dpad([0.1, -0.1]).iter().all(|p| !p.2));
+        // Stick up draws the knob above the middle, on screen.
+        assert_eq!(knob([50.0, 50.0], [0.0, 1.0], 40.0), [50.0, 40.0]);
+        assert_eq!(knob([50.0, 50.0], [1.0, 0.0], 40.0), [60.0, 50.0]);
+    }
+}
@@ -193,6 +193,8 @@ pub struct Settings {
    pub dynamic_area_y: f32,
    /// Scales every control without changing the saved sizes (0.5-2).
    pub button_scale: f32,
+    /// The touch marker's diameter in GUI pixels (16-64).
+    pub circle_size: f32,
 }

 impl Default for Settings {
@@ -239,6 +241,7 @@ impl Default for Settings {
            dynamic_area_x: 0.25,
            dynamic_area_y: 1.0,
            button_scale: 1.0,
+            circle_size: 32.0,
        }
    }
 }
@@ -282,6 +285,7 @@ impl Settings {
            *v = finite_or(*v, 1.0).clamp(0.1, 3.0);
        }
        self.button_scale = finite_or(self.button_scale, 1.0).clamp(0.5, 2.0);
+        self.circle_size = finite_or(self.circle_size, 32.0).clamp(16.0, 64.0);
        self.dynamic_area_x = finite_or(self.dynamic_area_x, 0.25).clamp(0.0, 1.0);
        self.dynamic_area_y = finite_or(self.dynamic_area_y, 1.0).clamp(0.0, 1.0);
    }
@@ -474,6 +478,17 @@ mod tests {
        assert_eq!(s.button_scale, 2.0);
    }

+    #[test]
+    fn the_marker_size_defaults_and_stays_in_range() {
+        let mut s: Settings = serde_json::from_str(r#"{"mode":"tap"}"#).unwrap();
+        assert_eq!(s.circle_size, 32.0);
+        for (bad, fixed) in [(f32::NAN, 32.0), (1.0, 16.0), (500.0, 64.0)] {
+            s.circle_size = bad;
+            s.sanitize();
+            assert_eq!(s.circle_size, fixed);
+        }
+    }
+
    #[test]
    fn left_hands_mirror_and_dpad_can_swap_jump_and_sneak() {
        let mut s = Settings::default();
@@ -104,7 +104,7 @@ pub fn read_metadata(root: &Path) -> UiMetadata {
        let Ok(text) = horizon_core::prepared_files::read_to_string(&p) else {
            continue;
        };
-        let Some(nine_slice) = serde_json::from_str(&text)
+        let Some(nine_slice) = crate::packs::first_json(text.as_bytes())
            .ok()
            .as_ref()
            .and_then(parse_nine_slice)
@@ -2025,6 +2025,28 @@ impl EditBox {
 mod tests {
    use super::*;

+    #[test]
+    fn notes_after_a_sprites_metadata_keep_its_nine_slice() {
+        // Gson stops reading after the first value, so vanilla keeps this nine slice
+        // (CozyUI+'s highlighted button, #3046).
+        let root = std::env::temp_dir().join(format!("horizon-ui-meta-{}", std::process::id()));
+        let widget = root.join("assets/minecraft/textures/gui/sprites/widget");
+        std::fs::create_dir_all(&widget).unwrap();
+        std::fs::write(
+            widget.join("button_highlighted.png.mcmeta"),
+            "{\"gui\": {\"scaling\": {\"type\": \"nine_slice\", \"width\": 80, \"height\": 20,\n\
+             \"border\": {\"left\": 34, \"top\": 8, \"right\": 34, \"bottom\": 8}}}}\n\n// 0  10\n// 1  8\n",
+        )
+        .unwrap();
+        let metadata = read_metadata(&root);
+        std::fs::remove_dir_all(&root).unwrap();
+        let slice = metadata.0["gui/sprites/widget/button_highlighted"];
+        assert_eq!(
+            (slice.width, slice.height, slice.border),
+            (80, 20, [34, 8, 34, 8])
+        );
+    }
+
    /// The quads' destination rectangles and their UVs.
    fn quads(batch: &HudBatch) -> Vec<([f32; 4], [f32; 4])> {
        batch
@@ -13,6 +13,8 @@ pub enum Cursor {
    #[default]
    Arrow,
    PointingHand,
+    /// `CursorTypes.IBEAM`: over a text field that takes input.
+    Ibeam,
    NotAllowed,
    /// `CursorTypes.RESIZE_NS`: a scroller held vertically (`MerchantScreen`).
    ResizeNs,
@@ -55,6 +57,18 @@ pub fn slider_cursor(hovered: bool, active: bool, dragging: bool) {
    }
 }

+/// `EditBox.handleCursor`: a hovered text field shows the I-beam, or the
+/// forbidden sign when it takes no input.
+pub fn text_cursor(hovered: bool, editable: bool) {
+    if hovered {
+        request_cursor(if editable {
+            Cursor::Ibeam
+        } else {
+            Cursor::NotAllowed
+        });
+    }
+}
+
 /// The cursor the frame asked for, and back to the arrow for the next one
 /// (the window shows the arrow unless a widget asks).
 pub fn take_cursor() -> Cursor {
@@ -429,6 +443,16 @@ pub fn record_as(label: &str, [x, y, w, h]: [f32; 4], enabled: bool, kind: Kind)
 mod cursor_tests {
    use super::*;

+    #[test]
+    fn a_hovered_text_field_asks_for_the_i_beam() {
+        let _ = take_cursor();
+        text_cursor(false, true);
+        assert_eq!(take_cursor(), Cursor::Arrow);
+        text_cursor(true, true);
+        assert_eq!(take_cursor(), Cursor::Ibeam);
+        text_cursor(true, false);
+        assert_eq!(take_cursor(), Cursor::NotAllowed);
+    }
    #[test]
    fn a_dragged_slider_asks_for_the_horizontal_resize_cursor() {
        let _ = take_cursor();
@@ -9,6 +9,9 @@ use horizon_core::random::{LegacyRandom, LevelRandom};
 use horizon_world::registry::BlockStateId;
 use std::sync::Arc;

+mod pending_entity;
+pub use pending_entity::{EntityLoadReason, PendingEntity};
+
 mod modified;
 pub use modified::ModifiedChunks;

@@ -81,7 +84,7 @@ pub struct World {
    /// incrementally by streaming.
    pub light_edits: Vec<((i32, i32, i32), u32, u32)>,
    /// Saved entities of chunks that just loaded, spawned by the game.
-    pub loaded_entities: Vec<((i32, i32), Vec<horizon_world::nbt::Tag>)>,
+    pub loaded_entities: Vec<((i32, i32), Vec<PendingEntity>)>,
    /// Chunks loaded since the level's last pass, their entity sections not
    /// ready yet (`PersistentEntitySectionManager`'s PENDING), empty ones too:
    /// the pass ends by readying them (`processPendingLoads`).
@@ -215,6 +218,12 @@ impl Weather {
    }
 }
 impl World {
+    /// Queue ordinary NBT; transient transfer state is never decoded from it.
+    pub fn queue_entity_nbt(&mut self, key: (i32, i32), tags: Vec<horizon_world::nbt::Tag>) {
+        self.loaded_entities
+            .push((key, tags.into_iter().map(PendingEntity::from).collect()));
+    }
+
    pub fn new(air: BlockStateId, seed: i64) -> Self {
        Self {
            shape: LevelShape::OVERWORLD,
@@ -0,0 +1,89 @@
+//! Pending entity NBT and the runtime context that must not be stored inside it.
+use horizon_world::nbt::Tag;
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum EntityLoadReason {
+    Ordinary,
+    TeleportedTnt,
+}
+
+#[derive(Clone, Debug)]
+pub struct PendingEntity {
+    tag: Tag,
+    reason: EntityLoadReason,
+}
+
+impl From<Tag> for PendingEntity {
+    fn from(tag: Tag) -> Self {
+        Self {
+            tag,
+            reason: EntityLoadReason::Ordinary,
+        }
+    }
+}
+
+impl PendingEntity {
+    /// Only an in-memory TNT transfer supplies this context, never saved NBT.
+    pub fn after_tnt_portal(tag: Tag) -> Self {
+        Self {
+            tag,
+            reason: EntityLoadReason::TeleportedTnt,
+        }
+    }
+
+    pub fn into_parts(self) -> (Tag, EntityLoadReason) {
+        (self.tag, self.reason)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn ordinary_nbt_cannot_request_transient_portal_state() {
+        for marker in [0, 1] {
+            let tag = Tag::compound([("horizon:tnt_used_portal", Tag::Byte(marker))]);
+            let (loaded, reason) = PendingEntity::from(tag.clone()).into_parts();
+            assert_eq!(loaded, tag);
+            assert_eq!(reason, EntityLoadReason::Ordinary);
+        }
+    }
+
+    #[test]
+    fn queue_swaps_and_appends_keep_each_entitys_context_and_order() {
+        let ordinary = Tag::compound([("id", Tag::String("ordinary".into()))]);
+        let transfer = Tag::compound([("id", Tag::String("transfer".into()))]);
+        let mut batches = vec![(
+            (1, 2),
+            vec![
+                ordinary.clone().into(),
+                PendingEntity::after_tnt_portal(transfer.clone()),
+            ],
+        )];
+        let mut waiting = std::mem::take(&mut batches);
+        batches.push(((3, 4), vec![ordinary.clone().into()]));
+        waiting.append(&mut batches);
+        assert!(batches.is_empty());
+        let mut batches = waiting.into_iter();
+        let (key, entities) = batches.next().unwrap();
+        assert_eq!(key, (1, 2));
+        let mut entities = entities.into_iter();
+        assert_eq!(
+            entities.next().unwrap().into_parts(),
+            (ordinary.clone(), EntityLoadReason::Ordinary)
+        );
+        assert_eq!(
+            entities.next().unwrap().into_parts(),
+            (transfer, EntityLoadReason::TeleportedTnt)
+        );
+        assert!(entities.next().is_none());
+        let (key, entities) = batches.next().unwrap();
+        assert_eq!(key, (3, 4));
+        assert_eq!(
+            entities.into_iter().next().unwrap().into_parts(),
+            (ordinary, EntityLoadReason::Ordinary)
+        );
+        assert!(batches.next().is_none());
+    }
+}
@@ -26,6 +26,7 @@ horizon-hooks = { path = "../horizon-hooks" }
 horizon-optifine = { path = "../horizon-optifine" }
 # The server thread ahead of the workers (MinecraftServer.spin's Thread.setPriority).
 horizon-threads = { path = "../horizon-threads" }
+horizon-perf-format = { path = "../horizon-perf-format" }
 horizon-hdr = { path = "../horizon-hdr" }
 horizon-world = { path = "../horizon-world" }
 horizon-protocol = { path = "../horizon-protocol" }
@@ -73,6 +74,8 @@ horizon-theme = { path = "../horizon-theme" }
 # anonymous "I'm playing" ping is the Horizon layer's (`horizon-heartbeat`, in the official executable).
 horizon-telemetry = { path = "../horizon-telemetry", default-features = false }
 horizon-bench = { path = "../horizon-bench" }
+# The machine and process probes (the dedicated server's performance report).
+horizon-system = { path = "../horizon-system" }
 crc32fast = "1"
 zip = { version = "9.1.3", default-features = false, features = ["deflate"] }
 # Controllers (evdev + libudev on Linux, IOKit on macOS, Windows.Gaming.Input); the `controllers` feature.
@@ -90,10 +93,6 @@ fs4 = { version = "1.1.0", default-features = false, features = ["sync"] }
 rustix = { version = "1", default-features = false, features = ["std", "time", "process", "fs"] }

 [target.'cfg(windows)'.dependencies]
-# Resolve virtualized folders to shell-compatible physical paths.
-dunce = "1.0.5"
-# Use the registered URI handler without routing links through Explorer/cmd.
-open = { version = "5.4.5", features = ["shellexecute-on-windows"] }
 # DirectX 12, where Vulkan has no adapter or device, or by choice (`graphicsApi`, graphics.rs).
 # Shaders compile with FXC (d3dcompiler_47.dll, part of Windows), or on integrated GPUs with DXC
 # (dxcompiler.dll beside the game, gfx/dx12_compiler.rs).
@@ -132,7 +131,9 @@ friends = ["dep:horizon-friends"]
 rng-trace = ["horizon-core/rng-trace", "horizon-client-lib/rng-trace"]
 # Rust's allocations go to the system heap instead of mimalloc, where heap profilers that replace
 # malloc (heaptrack, valgrind's massif) see them. For profiling only: mimalloc is faster.
-system-allocator = []
+system-allocator = ["horizon-threads/system-allocator"]
+# mimalloc that counts each thread's allocations and frees (`stats` replies with `alloc`).
+alloc-count = ["horizon-threads/alloc-count"]
 # mimalloc with a tag on each block: `horizon-ctl memory` lists the live heap by startup step and
 # thread (`heap_by_tag_mb`). For measuring only: each block costs 16 bytes more.
 alloc-census = ["horizon-threads/alloc-census"]
@@ -176,5 +177,6 @@ workspace = true
 [dev-dependencies]
 horizon-client-render = { path = "../horizon-client-render", features = ["test-support"] }
 horizon-items = { path = "../horizon-items", features = ["test-support"] }
+horizon-perf = { path = "../horizon-perf" }
 # Every WGSL shader translated as wgpu's DirectX 12 backend does (gfx.rs tests).
 naga = { version = "30.0.1", features = ["wgsl-in", "hlsl-out", "msl-out", "spv-out"] }
@@ -301,7 +301,6 @@
  "Coarse distant terrain in local worlds. Integrated GPUs stop at 128 chunks.": "Growwe verre terrein in plaaslike wêrelde. Geïntegreerde GPU's stop by 128 stukke.",
  "Reduced draws far terrain coarser: faster on this integrated GPU.": "Verminder trek veel terrein growwer: vinniger op hierdie geïntegreerde GPU.",
  "Reduced draws far terrain coarser, for GPUs it slows down.": "Verminder trek veel terrein growwer, vir GPU's word dit stadiger.",
-  "Field of view. Wider shows more terrain at once.": "Gesigsveld. Wyer wys meer terrein op een slag.",
  "Caps frames per second; a cap saves power and heat.": "Caps rame per sekonde; 'n pet spaar krag en hitte.",
  "Waits for the display's refresh: no tearing, a little latency.": "Wag vir die verversing van die skerm: geen skeur nie, 'n bietjie vertraging.",
  "Size of menus and the HUD.": "Grootte van spyskaarte en die HUD.",
@@ -339,13 +338,11 @@
  "Smooths jagged edges. FXAA: softer. TAA: smoothest, moving things may trail.": "Maak gekartelde rande glad. FXAA: sagter. TAA: gladste, bewegende dinge kan loop.",
  "Renders the world smaller and rebuilds it with TAA. Faster, softer.": "Maak die wêreld kleiner en herbou dit met TAA. Vinniger, sagter.",
  "Sharpens the upscaled picture. Higher: crisper edges, more shimmer.": "Verskerp die opgeskaalde beeld. Hoër: skerper rande, meer flikkering.",
-  "HDR output on an HDR display: lava, fire and sunlight shine brighter.": "HDR-uitset op 'n HDR-skerm: lawa, vuur en sonlig skyn helderder.",
  "How frames reach the screen while VSync is off.": "Hoe rame die skerm bereik terwyl VSync af is.",
  "Efficient sleeps until the next frame; Precise spins, like vanilla.": "Doeltreffende slaap tot die volgende raam; Presiese draaie, soos vanielje.",
  "Fills the screen (borderless).": "Vul die skerm (randloos).",
  "Brightens dark places.": "Verhelder donker plekke.",
  "Lowers the frame rate when minimised, or idle too.": "Verlaag die raamtempo wanneer dit geminimaliseer word, of ook ledig.",
-  "Sways the view while walking.": "Swaai die uitsig terwyl jy stap.",
  "Fades newly loaded chunks in.": "Vervaag nuutgelaaide stukke in.",
  "Darkens the screen's edges.": "Maak die skerm se rande donkerder.",
  "Shows when the world saves.": "Wys wanneer die wêreld red.",
@@ -556,7 +553,6 @@
  "horizon.splitscreen.online_only": "Hierdie bediener is in aanlynmodus: vanlyn profiele kan nie daarby aansluit nie; elke speler het sy eie Minecraft-rekening nodig.",
  "horizon.splitscreen.own_account": "Hierdie bediener vereis elke speler se eie Minecraft-rekening",
  "horizon.splitscreen.local_only": "Ander spelers kan slegs met hul eie Minecraft-rekening by hierdie bediener aansluit: vanlyn profiele speel in jou wêreld, op LAN of op 'n bediener op jou plaaslike netwerk.",
-  "Hides models behind opaque blocks. Async checks off-thread; entities tick.": "Versteek modelle agter ondeursigtige blokke. Async kontroleer af-draad; entiteite merk.",
  "Block Entities": "Blok Entiteite",
  "Shulker Boxes": "Shulkerbokse",
  "Reuses settled boxes; lid movement stays animated.": "Hergebruik afgewikkelde bokse; dekselbeweging bly geanimeerd.",
@@ -621,10 +617,6 @@
  "horizon.agent.session_opened": "Geopen vir hierdie sessie deur die program wat die speletjie begin het.",
  "horizon.agent.socket": "Sok: %s (kopieer die besonderhede vir sy volledige pad)",
  "horizon.agent.local_only": "Slegs plaaslik: agente op hierdie rekenaar, nooit die netwerk nie.",
-  "%s nits": "%s nete",
-  "Auto (%s nits)": "Outo (%s nete)",
-  "%.2f nits": "%.2f nete",
-  "Hides models behind opaque blocks. Entities update. Off with custom packs.": "Versteek modelle agter ondeursigtige blokke. Entiteite-opdatering. Af met pasgemaakte pakke.",
  "Entity Culling Precheck": "Entiteit-uitdunning-voorafkontrole",
  "Runs the mob AABB precheck after this many loaded mobs. Zero disables it.": "Voer die skare-AABB-voorafkontrole uit ná hierdie aantal gelaaide skare. Nul skakel dit af.",
  "%s mobs": "%s skares",
@@ -301,7 +301,6 @@
  "Coarse distant terrain in local worlds. Integrated GPUs stop at 128 chunks.": "التضاريس البعيدة الخشنة في العوالم المحلية. تتوقف وحدات معالجة الرسومات المدمجة عند 128 قطعة.",
  "Reduced draws far terrain coarser: faster on this integrated GPU.": "تم تقليل الرسم على التضاريس البعيدة: بشكل أسرع على وحدة معالجة الرسومات المدمجة هذه.",
  "Reduced draws far terrain coarser, for GPUs it slows down.": "يتم تقليل الرسوم على التضاريس البعيدة بشكل أكثر خشونة، أما بالنسبة لوحدات معالجة الرسومات فإنها تبطئ.",
-  "Field of view. Wider shows more terrain at once.": "مجال الرؤية. يُظهر العرض الأوسع المزيد من التضاريس في وقت واحد.",
  "Caps frames per second; a cap saves power and heat.": "قبعات الإطارات في الثانية الواحدة؛ غطاء يوفر الطاقة والحرارة.",
  "Waits for the display's refresh: no tearing, a little latency.": "في انتظار تحديث الشاشة: بدون تمزق، وقليل من زمن الوصول.",
  "Size of menus and the HUD.": "حجم القوائم وHUD.",
@@ -339,13 +338,11 @@
  "Smooths jagged edges. FXAA: softer. TAA: smoothest, moving things may trail.": "ينعم الحواف الخشنة. FXAA: أكثر ليونة. TAA: قد تتبع الأشياء الأكثر سلاسة وتحريكًا.",
  "Renders the world smaller and rebuilds it with TAA. Faster, softer.": "يجعل العالم أصغر حجمًا ويعيد بنائه باستخدام TAA. أسرع وأكثر ليونة.",
  "Sharpens the upscaled picture. Higher: crisper edges, more shimmer.": "يزيد حدة الصورة المرتقاة. أعلى: حواف أوضح ووميض أكثر.",
-  "HDR output on an HDR display: lava, fire and sunlight shine brighter.": "إخراج HDR على شاشة HDR: تتألق الحمم البركانية والنار وأشعة الشمس بشكل أكثر سطوعًا.",
  "How frames reach the screen while VSync is off.": "كيفية وصول الإطارات إلى الشاشة أثناء إيقاف تشغيل VSync.",
  "Efficient sleeps until the next frame; Precise spins, like vanilla.": "ينام بكفاءة حتى الإطار التالي؛ يدور بدقة، مثل الفانيليا.",
  "Fills the screen (borderless).": "يملأ الشاشة (بلا حدود).",
  "Brightens dark places.": "يضيء الأماكن الداكنة.",
  "Lowers the frame rate when minimised, or idle too.": "يخفض معدل الإطارات عند تصغيره أو في وضع الخمول أيضًا.",
-  "Sways the view while walking.": "يتأرجح المنظر أثناء المشي.",
  "Fades newly loaded chunks in.": "يتلاشى القطع المحملة حديثًا.",
  "Darkens the screen's edges.": "لتغميق حواف الشاشة.",
  "Shows when the world saves.": "يظهر عندما ينقذ العالم.",
@@ -556,7 +553,6 @@
  "horizon.splitscreen.online_only": "هذا الخادم في وضع الاتصال: لا يمكن للملفات الشخصية غير المتصلة الانضمام إليه، وكل لاعب يحتاج حساب Minecraft خاصًا به.",
  "horizon.splitscreen.own_account": "يحتاج هذا الخادم حساب Minecraft خاصًا بكل لاعب",
  "horizon.splitscreen.local_only": "يمكن للاعبين الآخرين الانضمام إلى هذا الخادم فقط بحساب Minecraft خاص بهم: أما الملفات الشخصية غير المتصلة فتلعب في عالمك، على LAN أو على خادم في شبكتك المحلية.",
-  "Hides models behind opaque blocks. Async checks off-thread; entities tick.": "يخفي النماذج خلف الكتل المعتمة. غير متزامن يتحقق من خارج الموضوع؛ علامة الكيانات.",
  "Block Entities": "حظر الكيانات",
  "Shulker Boxes": "صناديق شوكر",
  "Reuses settled boxes; lid movement stays animated.": "إعادة استخدام الصناديق المستقرة؛ تبقى حركة الغطاء متحركة.",
@@ -621,10 +617,6 @@
  "horizon.agent.session_opened": "تم فتحه لهذه الجلسة بواسطة البرنامج الذي بدأ اللعبة.",
  "horizon.agent.socket": "المقبس: %s (انسخ التفاصيل لمساره الكامل)",
  "horizon.agent.local_only": "محلي فقط: الوكلاء على هذا الكمبيوتر، وليس الشبكة أبدًا.",
-  "%s nits": "%s القمل",
-  "Auto (%s nits)": "تلقائي (%s شمعة في المتر المربع)",
-  "%.2f nits": "%.2f القمل",
-  "Hides models behind opaque blocks. Entities update. Off with custom packs.": "يخفي النماذج خلف الكتل المعتمة. تحديث الكيانات مع حزم مخصصة.",
  "Entity Culling Precheck": "فحص استبعاد الكيانات المسبق",
  "Runs the mob AABB precheck after this many loaded mobs. Zero disables it.": "يشغّل فحص AABB للغوغاء بعد هذا العدد من الغوغاء المحمّلين. صفر يعطّله.",
  "%s mobs": "%s غوغاء",
@@ -301,7 +301,6 @@
  "Coarse distant terrain in local worlds. Integrated GPUs stop at 128 chunks.": "Yerli dünyalarda kobud uzaq ərazi. İnteqrasiya edilmiş GPU-lar 128 hissədə dayanır.",
  "Reduced draws far terrain coarser: faster on this integrated GPU.": "Azaldılmış ərazini daha qaba çəkir: bu inteqrasiya olunmuş GPU-da daha sürətli.",
  "Reduced draws far terrain coarser, for GPUs it slows down.": "Azaldılmış ərazini daha qaba çəkir, GPU-lar üçün isə yavaşlayır.",
-  "Field of view. Wider shows more terrain at once.": "Baxış sahəsi. Daha geniş bir anda daha çox ərazini göstərir.",
  "Caps frames per second; a cap saves power and heat.": "Saniyədə kadrların sayı; qapaq enerjiyə və istiliyə qənaət edir.",
  "Waits for the display's refresh: no tearing, a little latency.": "Ekranın təzələnməsini gözləyir: cırılma, bir az gecikmə.",
  "Size of menus and the HUD.": "Menyuların ölçüsü və HUD.",
@@ -339,13 +338,11 @@
  "Smooths jagged edges. FXAA: softer. TAA: smoothest, moving things may trail.": "Kəsik kənarları hamarlayır. FXAA: daha yumşaq. TAA: ən hamar, hərəkətli şeylər cığır çəkə bilər.",
  "Renders the world smaller and rebuilds it with TAA. Faster, softer.": "Dünyanı daha kiçik edir və TAA ilə yenidən qurur. Daha sürətli, daha yumşaq.",
  "Sharpens the upscaled picture. Higher: crisper edges, more shimmer.": "Böyüdülmüş təsviri kəskinləşdirir. Daha yüksək: daha aydın kənarlar, daha çox parıltı.",
-  "HDR output on an HDR display: lava, fire and sunlight shine brighter.": "HDR displeydə HDR çıxışı: lava, yanğın və günəş işığı daha parlaq parlayır.",
  "How frames reach the screen while VSync is off.": "VSync söndürüldükdə çərçivələr ekrana necə çatır.",
  "Efficient sleeps until the next frame; Precise spins, like vanilla.": "Növbəti kadra qədər səmərəli yuxular; Vanil kimi dəqiq spinlər.",
  "Fills the screen (borderless).": "Ekranı doldurur (sərhədsiz).",
  "Brightens dark places.": "Qaranlıq yerləri işıqlandırır.",
  "Lowers the frame rate when minimised, or idle too.": "Minimumlaşdırıldıqda və ya boş olduqda kadr sürətini azaldır.",
-  "Sways the view while walking.": "Gəzərkən mənzərəni yelləyir.",
  "Fades newly loaded chunks in.": "Yeni yüklənmiş parçaları sönür.",
  "Darkens the screen's edges.": "Ekranın kənarlarını qaraldır.",
  "Shows when the world saves.": "Dünyanın nə vaxt xilas etdiyini göstərir.",
@@ -556,7 +553,6 @@
  "horizon.splitscreen.online_only": "Bu server onlayn rejimdədir: oflayn profillər ona qoşula bilməz, hər oyunçunun öz Minecraft hesabı lazımdır.",
  "horizon.splitscreen.own_account": "Bu server hər oyunçunun öz Minecraft hesabını tələb edir",
  "horizon.splitscreen.local_only": "Digər oyunçular bu serverə yalnız öz Minecraft hesabları ilə qoşula bilər: oflayn profillər sizin dünyanızda, LAN-da və ya yerli şəbəkənizdəki serverdə oynayır.",
-  "Hides models behind opaque blocks. Async checks off-thread; entities tick.": "Modelləri qeyri-şəffaf blokların arxasında gizlədir. Async-dən kənar yoxlayır; qurumlar işarələyir.",
  "Block Entities": "Blok obyektləri",
  "Shulker Boxes": "Shulker qutuları",
  "Reuses settled boxes; lid movement stays animated.": "Yerləşmiş qutuları təkrar istifadə edir; qapaq hərəkəti canlı qalır.",
@@ -621,10 +617,6 @@
  "horizon.agent.session_opened": "Oyuna başlayan proqram tərəfindən bu sessiya üçün açıldı.",
  "horizon.agent.socket": "Soket: %s (tam yolu üçün təfərrüatları kopyalayın)",
  "horizon.agent.local_only": "Yalnız yerli: bu kompüterdəki agentlər, heç vaxt şəbəkə.",
-  "%s nits": "%s nit",
-  "Auto (%s nits)": "Avtomatik (%s nits)",
-  "%.2f nits": "%.2f nit",
-  "Hides models behind opaque blocks. Entities update. Off with custom packs.": "Modelləri qeyri-şəffaf blokların arxasında gizlədir. Müəssisələrin yenilənməsi. Fərdi paketlərlə endirim.",
  "Entity Culling Precheck": "Obyekt kəsmə ön yoxlaması",
  "Runs the mob AABB precheck after this many loaded mobs. Zero disables it.": "Yüklənmiş mob sayı bu həddə çatanda mob AABB ön yoxlamasını işlədir. Sıfır onu söndürür.",
  "%s mobs": "%s mob",
@@ -301,7 +301,6 @@
  "Coarse distant terrain in local worlds. Integrated GPUs stop at 128 chunks.": "Урындағы донъяларҙа ҡырыҫ алыҫ ерҙәр. Интеграцияланған график процессорҙар 128 өлөштә туҡтай.",
  "Reduced draws far terrain coarser: faster on this integrated GPU.": "Ҡыҫҡартылған тарта алыҫ ер ҡырыҫ: тиҙерәк был интеграцияланған GPU.",
  "Reduced draws far terrain coarser, for GPUs it slows down.": "Кәметелгән тарта алыҫ ер ҡырыҫыраҡ, GPUs өсөн ул яйлатып.",
-  "Field of view. Wider shows more terrain at once.": "Күренеш өлкәһе. Киңерәк бер юлы күберәк ерҙе күрһәтә.",
  "Caps frames per second; a cap saves power and heat.": "Ҡапҡастар кадрҙар секундына; ҡапҡас энергияны һәм йылылыҡты һаҡлай.",
  "Waits for the display's refresh: no tearing, a little latency.": "Дисплейҙы яңыртыуҙы көтә: йыртыу юҡ, бер аҙ тотҡарлыҡ.",
  "Size of menus and the HUD.": "Размер меню һәм HUD.",
@@ -339,13 +338,11 @@
  "Smooths jagged edges. FXAA: softer. TAA: smoothest, moving things may trail.": "Тешле ситтәрен тигеҙләй. ФХАА: йомшағыраҡ. ТАА: иң шыма, хәрәкәт итеүсе әйберҙәр эҙҙәре булыуы мөмкин.",
  "Renders the world smaller and rebuilds it with TAA. Faster, softer.": "Донъяны бәләкәйерәк итә һәм уны ТАА менән яңынан төҙөй. Тиҙерәк, йомшағыраҡ.",
  "Sharpens the upscaled picture. Higher: crisper edges, more shimmer.": "Масштабланған һүрәтте үткерләндерә. Юғарыраҡ: ситтәр асығыраҡ, ялтырау күберәк.",
-  "HDR output on an HDR display: lava, fire and sunlight shine brighter.": "HDR дисплейында HDR сығышы: лава, ут һәм ҡояш нурҙары сағыуыраҡ балҡый.",
  "How frames reach the screen while VSync is off.": "Нисек кадрҙар экранға етә, ә VSync өҙөлгән.",
  "Efficient sleeps until the next frame; Precise spins, like vanilla.": "Һөҙөмтәле йоҡлай сираттағы кадрға тиклем; Теүәл әйләнештәр, ваниль кеүек.",
  "Fills the screen (borderless).": "Экранды тултыра (сикһеҙ).",
  "Brightens dark places.": "Ҡараңғы урындарҙы яҡтырта.",
  "Lowers the frame rate when minimised, or idle too.": "Кадрҙар йышлығын түбәнәйтә, ҡасан минималь, йәки буш ла.",
-  "Sways the view while walking.": "Йөрөгәндә ҡарашты һелкетә.",
  "Fades newly loaded chunks in.": "Яңы тейәлгән өлөштәрҙе һүнә.",
  "Darkens the screen's edges.": "Экрандың ситтәрен ҡарайта.",
  "Shows when the world saves.": "Донъя ҡотҡарғанда күрһәтә.",
@@ -556,7 +553,6 @@
  "horizon.splitscreen.online_only": "Был сервер онлайн режимда: офлайн профилдәр уға ҡушыла алмай, һәр уйынсыға үҙ Minecraft иҫәбе кәрәк.",
  "horizon.splitscreen.own_account": "Был серверға һәр уйынсының үҙ Minecraft иҫәбе кәрәк",
  "horizon.splitscreen.local_only": "Башҡа уйынсылар был серверға үҙҙәренең Minecraft иҫәбенә генә ҡушыла ала: офлайн профилдәр һеҙҙең донъяла, LAN йәки һеҙҙең урындағы селтәрҙәге серверҙа уйнай.",
-  "Hides models behind opaque blocks. Async checks off-thread; entities tick.": "Моделдәрҙе асыҡ булмаған блоктар артында йәшерә. Ассинхрон тикшерә тышҡы еп; субъекттар галочкой.",
  "Block Entities": "Блок субъекттары",
  "Shulker Boxes": "Шулкер йәшниктәре",
  "Reuses settled boxes; lid movement stays animated.": "Ҡабаттан ҡуллана урынлаштырылған йәшниктәр; ҡапҡас хәрәкәте йәнле ҡала.",
@@ -621,10 +617,6 @@
  "horizon.agent.session_opened": "Был сессия өсөн уйынды башлаған программа асты.",
  "horizon.agent.socket": "Розетка: %s (уның тулы юлы өсөн реквизиттарҙы күсерергә)",
  "horizon.agent.local_only": "Урындағы ғына: был компьютерҙа агенттар, бер ҡасан да селтәр.",
-  "%s nits": "%s нит",
-  "Auto (%s nits)": "Авто (%s нит)",
-  "%.2f nits": "%.2f нит",
-  "Hides models behind opaque blocks. Entities update. Off with custom packs.": "Моделдәрҙе асыҡ булмаған блоктар артында йәшерә. Яңыртыу субъекттары. Ҡулланыусылар пакеттары менән өҙөлгән.",
  "Entity Culling Precheck": "Субъекттарҙы ҡырҡыуҙы алдан тикшереү",
  "Runs the mob AABB precheck after this many loaded mobs. Zero disables it.": "Моб AABB алдан тикшереүен был һандағы тейәлгән мобтан һуң башҡара. Ноль уны һүндерә.",
  "%s mobs": "%s моб",
@@ -301,7 +301,6 @@
  "Coarse distant terrain in local worlds. Integrated GPUs stop at 128 chunks.": "Грубая аддаленая мясцовасць у лакальных мірах. Убудаваныя графічныя працэсары спыняюцца на 128 кавалках.",
  "Reduced draws far terrain coarser: faster on this integrated GPU.": "Паменшанае малюнак больш грубай мясцовасці: хутчэй на гэтым убудаваным графічным працэсары.",
  "Reduced draws far terrain coarser, for GPUs it slows down.": "Зніжэнне малюе больш грубую мясцовасць, для графічных працэсараў гэта запавольваецца.",
-  "Field of view. Wider shows more terrain at once.": "Поле зроку. Шырэй паказвае адразу больш мясцовасці.",
  "Caps frames per second; a cap saves power and heat.": "Колькасць кадраў у секунду; шапка эканоміць энергію і цяпло.",
  "Waits for the display's refresh: no tearing, a little latency.": "Чакае абнаўлення дысплея: без разрыву, з невялікай затрымкай.",
  "Size of menus and the HUD.": "Памер меню і HUD.",
@@ -339,13 +338,11 @@
  "Smooths jagged edges. FXAA: softer. TAA: smoothest, moving things may trail.": "Згладжвае няроўныя краю. FXAA: мякчэй. TAA: самыя гладкія рэчы, якія рухаюцца, могуць цягнуцца.",
  "Renders the world smaller and rebuilds it with TAA. Faster, softer.": "Памяншае свет і перабудоўвае яго з TAA. Хутчэй, мякчэй.",
  "Sharpens the upscaled picture. Higher: crisper edges, more shimmer.": "Павялічвае рэзкасць павялічанай выявы. Вышэй: больш рэзкія краі, больш мігацення.",
-  "HDR output on an HDR display: lava, fire and sunlight shine brighter.": "Вывад HDR на дысплеі HDR: лава, агонь і сонечнае святло ззяюць ярчэй.",
  "How frames reach the screen while VSync is off.": "Як кадры трапляюць на экран, калі VSync выключаны.",
  "Efficient sleeps until the next frame; Precise spins, like vanilla.": "Эфектыўнае спіць да наступнага кадра; Дакладныя спіны, як ваніль.",
  "Fills the screen (borderless).": "Запаўняе экран (без палёў).",
  "Brightens dark places.": "Асвятляе цёмныя месцы.",
  "Lowers the frame rate when minimised, or idle too.": "Зніжае частату кадраў пры згортванні або ў рэжыме чакання.",
-  "Sways the view while walking.": "Качае погляд падчас хады.",
  "Fades newly loaded chunks in.": "Змяншае толькі што загружаныя кавалкі.",
  "Darkens the screen's edges.": "Зацямняе краю экрана.",
  "Shows when the world saves.": "Паказвае, калі свет ратуе.",
@@ -556,7 +553,6 @@
  "horizon.splitscreen.online_only": "Гэты сервер у анлайн-рэжыме: афлайн-профілі не могуць далучыцца, кожнаму гульцу патрэбны ўласны ўліковы запіс Minecraft.",
  "horizon.splitscreen.own_account": "Гэтаму серверу патрэбны ўласны ўліковы запіс Minecraft для кожнага гульца",
  "horizon.splitscreen.local_only": "Іншыя гульцы могуць далучыцца да гэтага сервера толькі са сваім уліковым запісам Minecraft: афлайн-профілі гуляюць у вашым свеце, па LAN або на серверы ў вашай лакальнай сетцы.",
-  "Hides models behind opaque blocks. Async checks off-thread; entities tick.": "Хавае мадэлі за непразрыстымі блокамі. Async правярае па-за патокам; суб'ектаў цік.",
  "Block Entities": "Блокавыя аб'екты",
  "Shulker Boxes": "Скрынкі Шулкера",
  "Reuses settled boxes; lid movement stays animated.": "Паўторна выкарыстоўвае адстойнікі; рух вечка застаецца ажыўленым.",
@@ -621,10 +617,6 @@
  "horizon.agent.session_opened": "Адкрыты для гэтай сесіі праграмай, якая запусціла гульню.",
  "horizon.agent.socket": "Сокет: %s (скапіруйце дэталі для поўнага шляху)",
  "horizon.agent.local_only": "Толькі лакальна: агенты на гэтым кампутары, ніколі ў сетцы.",
-  "%s nits": "%s ніт",
-  "Auto (%s nits)": "Аўта (%s ніт)",
-  "%.2f nits": "%.2f ніт",
-  "Hides models behind opaque blocks. Entities update. Off with custom packs.": "Хавае мадэлі за непразрыстымі блокамі. Абнаўленне суб'ектаў. Выключыце спецыяльныя пакеты.",
  "Entity Culling Precheck": "Папярэдняя праверка адсячэння сутнасцей",
  "Runs the mob AABB precheck after this many loaded mobs. Zero disables it.": "Выконвае папярэднюю праверку AABB мабаў пасля гэтай колькасці загружаных мабаў. Нуль адключае яе.",
  "%s mobs": "%s мабаў",