Merge pull request #1650 from socksprox/fix/proxy-transfers

🤖 Agent: thank you! Merged after the contribution gate (checked against vanilla 26.3, tested in the modes it touches; pr_ready on main + the six gate PRs: fmt, clippy, 1327 tests, 112/112 affected harnesses) and this head's verify.

.gitattributes

@@ -3,3 +3,4 @@
 docs/launcher-commands.md text eol=lf
 docs/horizon-ctl-commands.md text eol=lf
 website/src/tokens.css text eol=lf
+docs/api/*-reference.md text eol=lf

.githooks/pre-push

@@ -1,2 +1,2 @@
 #!/bin/sh
-exec python3 tools/check_public_tree.py --history
+exec python3 tools/check_public_tree.py --pre-push

.github/workflows/ci.yml

@@ -430,7 +430,7 @@ jobs:
         env:
           RUSTUP_TOOLCHAIN: stable
         run: python tools/test_float_log_parity.py
-  portable-mod:
+  jfr-analysis:
     if: github.event_name == 'workflow_dispatch'
     runs-on: [self-hosted, linux, horizon-game]
     steps:
@@ -442,101 +442,7 @@ jobs:
         with:
           distribution: temurin
           java-version: '25'
-      - name: Compile original mod and test metrics
-        run: python tools/build_mod.py
       - name: Verify streaming JFR analysis against the JDK exporter
         run: python tools/test_jfr.py
       - name: Verify ZGC pause and allocation event interpretation
         run: python tools/test_jfr.py --gc zgc
-      - name: Build pinned portable packs
-        run: python tools/build_pack.py
-      - name: Measure isolated worker pacing on this platform
-        run: python -c "from tools.build_mod import benchmark_workers; benchmark_workers()"
-      - name: Measure isolated debounce queue polling
-        run: python -c "from tools.build_mod import benchmark_debounce; benchmark_debounce()"
-      - name: Measure wakeable idle queue latency
-        run: python -c "from tools.build_mod import benchmark_idle; benchmark_idle()"
-      - name: Measure object allocations with compact headers off and on
-        run: python -c "from tools.build_mod import benchmark_headers; benchmark_headers()"
-      - name: Test pack integrity and comparisons
-        run: python -m unittest discover -s tests -v
-      - name: Start recommended OpenGL macOS clients and verify framebuffer readback
-        if: runner.os == 'macOS'
-        run: |
-          python tools/test_client_graphics.py --native-display
-          cp dist/client-graphics-smoke.json dist/client-graphics-macos-title.json
-          python tools/test_client_graphics.py --native-display --world
-          cp dist/client-graphics-smoke.json dist/client-graphics-macos-world.json
-      - name: Compile the private dispatch fixture
-        run: python -c "from tools.build_mod import build_dispatch_fixture; build_dispatch_fixture()"
-      - name: Compile the private integrated-server graphics fixture
-        run: python -c "from tools.build_mod import build_integration_fixture; build_integration_fixture('server-graphics', 'dev.horizonlab.metrics.ServerGraphicsIntegration', fixture_dependencies={})"
-      - name: Compile the private tick-manager state fixture
-        run: python -c "from tools.build_mod import build_integration_fixture; build_integration_fixture('tick-state', 'dev.horizonlab.metrics.TickStateIntegration')"
-      - name: Compile the private terrain tick membership fixture
-        run: python -c "from tools.build_mod import build_tick_dedup_fixture; build_tick_dedup_fixture()"
-      - name: Compile the private culling whitelist fixture
-        run: python -c "from tools.build_mod import build_culling_empty_fixture; build_culling_empty_fixture()"
-      - name: Compile the private culling ray geometry fixture
-        run: python -c "from tools.build_mod import build_integration_fixture; build_integration_fixture('culling-rays', 'dev.horizonlab.dispatch.CullingRayIntegration', ['entityculling'], ['CullingRayAccess'])"
-      - name: Compile the private terrain position lookup fixture
-        run: python -c "from tools.build_mod import build_integration_fixture; build_integration_fixture('terrain-position', 'dev.horizonlab.dispatch.PositionIntegration')"
-      - name: Compile the private terrain quad reuse fixture
-        run: python -c "from tools.build_mod import build_integration_fixture; build_integration_fixture('quad-reuse', 'dev.horizonlab.dispatch.QuadReuseIntegration')"
-      - name: Compile the private object-size agent and terrain quad fixture
-        run: python -c "from tools.test_quad_sizes import build_agent; from tools.build_mod import build_integration_fixture; build_agent(); build_integration_fixture('quad-size', 'dev.horizonlab.dispatch.QuadSizeIntegration')"
-      - name: Compile the private terrain read shutdown fixture
-        run: python -c "from tools.build_mod import build_integration_fixture; build_integration_fixture('terrain-read', 'dev.horizonlab.dispatch.TerrainReadIntegration')"
-      - name: Install headless graphics libraries for applied-hook checks
-        if: runner.os == 'Linux'
-        run: sudo apt-get update && sudo apt-get install -y xvfb libgl1 libegl1 libvulkan1 mesa-vulkan-drivers libasound2t64 libxkbcommon0
-      - name: Verify integrated-server graphics report against the actual device
-        run: python tools/test_server_graphics.py ${{ runner.os == 'macOS' && '--native-display' || '' }}
-      - name: Exercise the applied dispatcher hooks and upstream rejection path
-        if: runner.os == 'Linux'
-        run: python tools/test_dispatch.py
-      - name: Verify applied tick membership transitions and allocation
-        if: runner.os == 'Linux'
-        run: python tools/test_tick_dedup.py
-      - name: Verify live culling whitelist registration and empty iteration
-        if: runner.os == 'Linux'
-        run: python tools/test_culling_empty.py
-      - name: Compare applied culling ray geometry and provider queries
-        if: runner.os == 'Linux'
-        run: python tools/test_culling_rays.py
-      - name: Verify actual full-data position lookup equivalence
-        if: runner.os == 'Linux'
-        run: python tools/test_terrain_position.py
-      - name: Verify actual terrain quad geometry and allocation
-        if: runner.os == 'Linux'
-        run: python tools/test_quad_reuse.py
-      - name: Measure actual builder and quad shallow sizes in both header modes
-        if: runner.os == 'Linux'
-        run: python tools/test_quad_sizes.py
-      - name: Verify interrupted DH reads and preserved shared futures
-        if: runner.os == 'Linux'
-        run: python tools/test_terrain_read.py
-      - name: Upload original mod and pack manifests only
-        uses: actions/upload-artifact@v4
-        with:
-          name: horizon-linux
-          path: |
-            dist/*.mrpack
-            dist/horizon-*.jar
-            dist/worker-pacing-benchmark.txt
-            dist/debounce-queue-benchmark.txt
-            dist/idle-queue-benchmark.txt
-            dist/object-header-benchmark.txt
-            dist/dispatch-integration.json
-            dist/tick-dedup-integration.json
-            dist/culling-empty-integration.json
-            dist/terrain-read-integration.json
-            dist/culling-rays-integration.json
-            dist/terrain-position-integration.json
-            dist/quad-reuse-integration.json
-            dist/quad-size-integration.json
-            dist/server-graphics-smoke.json
-            dist/client-graphics-smoke.json
-            dist/client-graphics-macos-title.json
-            dist/client-graphics-macos-world.json
-          retention-days: 3

.github/workflows/mod-registry.yml

@@ -0,0 +1,34 @@
+name: mod-registry
+# The submission service is its own workspace (crates/horizon-mod-registry), so the checks job doesn't build
+# it: this one does, when it or horizon-mods (the checks it shares with the launcher and the game) changes.
+on:
+  push:
+    branches: [main]
+    paths:
+      - 'crates/horizon-mods/**'
+      - 'crates/horizon-mod-registry/**'
+      - '.github/workflows/mod-registry.yml'
+  pull_request:
+    paths:
+      - 'crates/horizon-mods/**'
+      - 'crates/horizon-mod-registry/**'
+      - '.github/workflows/mod-registry.yml'
+permissions:
+  contents: read
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    defaults:
+      run:
+        working-directory: crates/horizon-mod-registry
+    steps:
+      - uses: actions/checkout@v4
+      - run: rustup toolchain install stable --profile minimal --component rustfmt --component clippy
+      - uses: Swatinem/rust-cache@v2
+        with:
+          workspaces: crates/horizon-mod-registry
+          save-if: ${{ github.ref == 'refs/heads/main' }}
+      - run: cargo +stable fmt --check
+      - run: cargo +stable clippy --all-targets --locked -- -D warnings
+      - run: cargo +stable test --locked

.github/workflows/release.yml

@@ -1,8 +1,8 @@
 name: release
 # Automatic game releases (docs/release-flow.md). After every green `checks` run on main, every 10 minutes (so a
 # release waiting for merges to settle goes out without another merge) and by hand, tools/release_train.py decides:
-# a release when pull requests merged since the last one changed what players run and the newest merged 5 minutes
-# ago (the oldest 20 minutes ago, if merges never pause), or at once for a pull request labelled release-now.
+# a release when 5 pull requests merged since the last one changed what players run and the newest merged 5 minutes
+# ago, or when the oldest has waited 6 hours, or at once for a pull request labelled release-now.
 # RELEASES_PAUSED=1 (repository variable) stops them; so does an open issue labelled release-blocker, forced runs too.
 # Builds Linux (an older Ubuntu, so the binary runs on any recent distribution and on NixOS through nix-ld) and
 # Windows on GitHub, macOS on the Mac mini's runner (MAC_RUNNER=macos-latest sends it to GitHub), then
@@ -367,10 +367,15 @@ jobs:
           TAG: ${{ needs.decide.outputs.tag }}
         run: |
           signature=(); [[ -f dist/SHA256SUMS.sig ]] && signature=(dist/SHA256SUMS.sig)
-          # The release and the latest at once: there is one channel (docs/release-flow.md).
+          # The release and the latest at once: there is one channel (docs/release-flow.md). Each archive gets a
+          # label (file#label), which GitHub's page shows instead of the file name, so nobody takes the game's
+          # files for the download (#1647). Launchers, servers and install.sh match the name, which stays.
           gh release create "$TAG" --target "${{ needs.decide.outputs.head }}" --title "$(cat notes/title.txt)" \
-            --notes-file notes/body.md --latest dist/horizon-linux-x86_64.tar.gz \
-            dist/horizon-windows-x64.zip dist/horizon-macos-arm64.zip dist/horizon-server-linux-x86_64.tar.gz \
+            --notes-file notes/body.md --latest \
+            "dist/horizon-linux-x86_64.tar.gz#Game files the launcher installs: Linux (horizon-linux-x86_64.tar.gz)" \
+            "dist/horizon-windows-x64.zip#Game files the launcher installs: Windows (horizon-windows-x64.zip)" \
+            "dist/horizon-macos-arm64.zip#Game files the launcher installs: macOS (horizon-macos-arm64.zip)" \
+            "dist/horizon-server-linux-x86_64.tar.gz#Dedicated server for Linux (horizon-server-linux-x86_64.tar.gz)" \
             dist/SHA256SUMS "${signature[@]}" dist/smoke-test.json
       - name: Dry run, the release that would be published
         if: needs.decide.outputs.dry_run == 'true'

AGENTS.md

@@ -24,8 +24,8 @@ Feature → files → harness for the most-changed areas: [docs/architecture.md]
 - 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. Every merge to main ships
-  ([docs/release-flow.md](docs/release-flow.md)).
+  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)).
 - Contributors first: `gh pr list --state open --search <area>` before you start; never duplicate theirs.
 
 ## Crates
@@ -43,12 +43,13 @@ Game workspace (root `Cargo.toml`); `launcher/` and `crates/horizon-telemetry-se
 | `horizon-server` | `horizon-server`: `server.toml`, CLI, supervisor of the headless game ([docs/hosting.md](docs/hosting.md)) |
 | `horizon-server-files` | `server.properties`, eula, ops/whitelist/bans, usercache |
 | `horizon-friends`, `horizon-relay` | Play with Friends: invite codes, encrypted tunnel, the relay ([docs/play-with-friends.md](docs/play-with-friends.md)) |
-| `horizon-shaderpack` | OptiFine/Iris packs: preprocessor, GLSL → WGSL ([docs/shader-packs.md](docs/shader-packs.md)) |
 | `horizon-mods`, `horizon-mod-sdk`, `cargo-horizon-mod` | Sandboxed WebAssembly mods: runtime, SDK + WIT, `cargo horizon-mod` ([docs/mods.md](docs/mods.md)) |
 | `horizon-port-pack` | Porting Java modpacks ([docs/modpacks.md](docs/modpacks.md)) |
+| `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-telemetry`, `horizon-telemetry-server`, `horizon-bench` | Opt-in data collection, its ingest server, the benchmark report format |
-| `horizon-dualsense`, `horizon-threads`, `horizon-release-sign`, `horizon-bots`, `voxel-kernels`, `xtask` | DualSense output, thread priorities, signed release checksums, load-test bots, occupancy kernels, repo tasks |
+| `horizon-dualsense`, `horizon-threads`, `horizon-release-sign`, `horizon-bots`, `xtask` | DualSense output, thread priorities, signed release checksums, load-test bots, repo tasks |
 | `launcher/` | GPUI launcher: `main.rs` (UI), `backend.rs` (installs, updates), `cli.rs`, `mcp.rs`, `*_page.rs` |
 
 Other top-level folders: `tools/` (harnesses and dev scripts), `tests/` (Python unit tests: `python3 -m
@@ -126,7 +127,6 @@ python3 tools/agent_control_e2e.py         # horizon-ctl / MCP end to end
 | Input | game.rs `fn window_event`, `fn key_pressed`, `fn play_mouse`; L: `keybinds.rs`, `keymapping.rs`, `key_names.rs`, `mouse.rs`, `input.rs`, `interaction_input.rs`, `gamepad.rs`, `osk.rs`, `clipboard.rs`; G: `pad.rs`, `pad_menu.rs` |
 | Audio | L: `audio.rs` (mixer), `sound_engine.rs`, `sound_events.rs`, `music.rs`, `ambience.rs`; G: `music.rs`, `subtitle_hud.rs` |
 | Resource packs | L: `packs.rs` + `packs/`, `pack_screen.rs`, `atlas_sources.rs`, `sprites.rs`, `mipmap.rs`, `model_library.rs`, `font.rs`, `lang.rs`; crate `horizon-assets`; G: `packs.rs` |
-| Shader packs | L: `shader_pack.rs` (Horizon WGSL packs), `java_pack.rs` + crate `horizon-shaderpack` (Iris/OptiFine), `gfx/pack_stages.rs`, `gfx/java_stages.rs`; G: `shader_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` |
@@ -151,19 +151,19 @@ python3 tools/agent_control_e2e.py         # horizon-ctl / MCP end to end
 
 ## The two single-player paths
 
-1. **In-frame (default since #1428):** the window's `Game` ticks the world itself, one level that follows
-   the player (`fn enter_dimension`). This is what Stable players run and what harnesses test.
-2. **Server thread (`--server-thread` or `HORIZON_SERVER_THREAD=1`):** `game/integrated.rs` runs a second
-   `Game` (`serving`) on a "Server thread" with one level per dimension; the window joins it as a client
-   through memory (`remote`), exactly as a LAN guest or a dedicated server's player does. Not at parity yet:
-   open `[server-thread]` issues list the gaps.
+1. **Server thread (default since #1514):** `game/integrated.rs` runs a second `Game` (`serving`) on a
+   "Server thread" with one level per dimension; the window joins it as a client through memory (`remote`),
+   exactly as a LAN guest or a dedicated server's player does. This is what players run. Open
+   `[server-thread]` issues list the gaps left.
+2. **In-frame (`--in-frame`, `--no-server-thread` or `HORIZON_SERVER_THREAD=0`):** the window's `Game` ticks
+   the world itself, one level that follows the player (`fn enter_dimension`). Most harnesses test this path.
 
 LAN guests and dedicated servers always use the server code, so a fix there serves both. Test both paths
 when you touch player-facing gameplay:
 
 ```sh
-cargo run --profile fast -p horizon-client -- --resources .local/horizon-client/26.3 --world T                   # in-frame
-cargo run --profile fast -p horizon-client -- --resources .local/horizon-client/26.3 --world T --server-thread   # server thread
+cargo run --profile fast -p horizon-client -- --resources .local/horizon-client/26.3 --world T               # server thread
+cargo run --profile fast -p horizon-client -- --resources .local/horizon-client/26.3 --world T --in-frame    # in-frame
 python3 tools/lan_e2e.py --check <name>                  # host in-frame, guest is a server client
 python3 tools/lan_e2e.py --server-thread --check <name>  # host on its server thread (portals, levels, distance, lava need it)
 python3 tools/parity.py dedicated_server server_entities server_player_damage

CONTRIBUTING.md

@@ -7,6 +7,11 @@ welcome on [Discord](https://discord.gg/HcTeMZxe5E).
 This repository holds the game, the launcher and the website, plus the tools, tests and docs that build, check and
 release them. Anything else (videos, Discord and other community material) lives elsewhere.
 
+**Where to start: [playhorizon.dev/hub](https://playhorizon.dev/hub).** It shows what is being done now and next
+([ROADMAP.md](ROADMAP.md) in the repository), the work board, good first tasks, and the forms to report a bug or
+suggest something. A pull request for a roadmap item carries its `roadmap:<id>` label; ideas go to the suggestion
+queue (the hub, or `/suggest` on Discord) rather than to issues, which are for bugs.
+
 ## Build it
 
 You need Rust (stable), Python 3.10+, JDK 25, and on Linux the ALSA and udev headers (`libasound2-dev libudev-dev`).
@@ -39,6 +44,17 @@ probe against Horizon, and compares their outputs. There are about 290 of them.
 
 Never commit game files, decompiled source or prepared resources (`.local/`): `tools/check_public_tree.py` rejects
 them (`git config core.hooksPath .githooks` runs it before every commit).
+The pre-push hook checks the full history reachable from the branches and tags being pushed. Run
+`python3 tools/check_public_tree.py --history` to audit the history of all local refs.
+
+## Only original code
+
+Horizon's code is written from Minecraft 26.3 itself and from public documentation, never from another mod, loader
+or renderer. Don't read, copy, translate or paraphrase the source of Iris, OptiFine, Sodium or any other project,
+and don't send code an AI tool wrote from it. Their user documentation and file formats are fine to read, and their
+packs and mods are fine to run and observe. Shader packs were removed on 24 October 2026 (#1561) because their code
+had been written from another project's source; they come back only as a clean-room rewrite from a written
+description of the pack format.
 
 ## Before asking for review
 

Cargo.lock

@@ -155,7 +155,7 @@ dependencies = [
  "objc2-foundation 0.3.2",
  "parking_lot",
  "percent-encoding",
- "windows-sys 0.59.0",
+ "windows-sys 0.60.2",
  "wl-clipboard-rs",
  "x11rb",
 ]
@@ -178,15 +178,6 @@ version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "175571dd1d178ced59193a6fc02dde1b972eb0bc56c892cde9beeceac5bf0f6b"
 
-[[package]]
-name = "ascii-canvas"
-version = "4.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ef1e3e699d84ab1b0911a1010c5c106aa34ae89aeac103be5ce0c3859db1e891"
-dependencies = [
- "term",
-]
-
 [[package]]
 name = "ash"
 version = "0.38.0+1.3.281"
@@ -214,30 +205,15 @@ version = "0.22.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "72b3254f16251a8381aa12e40e3c4d2f0199f8c6508fbecb9d91f575e0fbb8c6"
 
-[[package]]
-name = "bit-set"
-version = "0.8.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "08807e080ed7f9d5433fa9b275196cfc35414f66a0c79d864dc51a0d825231a3"
-dependencies = [
- "bit-vec 0.8.0",
-]
-
 [[package]]
 name = "bit-set"
 version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "09ec2f926cc3060f09db9ebc5b52823d85268d24bb917e472c0c4bea35780a7d"
 dependencies = [
- "bit-vec 0.9.1",
+ "bit-vec",
 ]
 
-[[package]]
-name = "bit-vec"
-version = "0.8.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5e764a1d40d510daf35e07be9eb06e75770908c27d411ee6c92109c9840eaaf7"
-
 [[package]]
 name = "bit-vec"
 version = "0.9.1"
@@ -283,16 +259,6 @@ dependencies = [
  "objc2 0.6.5",
 ]
 
-[[package]]
-name = "borsh"
-version = "1.8.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "553c5d846a6ba5150c65e3b1b8ec073bcf1abc20f9b7220de384a4443ea4e20a"
-dependencies = [
- "bytes",
- "cfg_aliases",
-]
-
 [[package]]
 name = "bumpalo"
 version = "3.20.3"
@@ -462,6 +428,8 @@ version = "0.13.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "af491d569909a7e4dee0ad7db7f5341fef5c614d5b8ec8cf765732aba3cff681"
 dependencies = [
+ "serde",
+ "termcolor",
  "unicode-width",
 ]
 
@@ -484,15 +452,6 @@ dependencies = [
  "crossbeam-utils",
 ]
 
-[[package]]
-name = "convert_case"
-version = "0.10.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "633458d4ef8c78b72454de2d54fd6ab2e60f9e02be22f3c6104cdc8a4e0fceb9"
-dependencies = [
- "unicode-segmentation",
-]
-
 [[package]]
 name = "coords-hud"
 version = "0.1.0"
@@ -797,41 +756,6 @@ dependencies = [
  "syn 2.0.119",
 ]
 
-[[package]]
-name = "darling"
-version = "0.20.11"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fc7f46116c46ff9ab3eb1597a45688b6715c6e628b5c133e288e709a29bcb4ee"
-dependencies = [
- "darling_core",
- "darling_macro",
-]
-
-[[package]]
-name = "darling_core"
-version = "0.20.11"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0d00b9596d185e565c2207a0b01f8bd1a135483d02d9b7b0a54b11da8d53412e"
-dependencies = [
- "fnv",
- "ident_case",
- "proc-macro2",
- "quote",
- "strsim",
- "syn 2.0.119",
-]
-
-[[package]]
-name = "darling_macro"
-version = "0.20.11"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fc34b93ccb385b40dc71c6fceac4b2ad23662c7eeb248cf10d529b7e055b6ead"
-dependencies = [
- "darling_core",
- "quote",
- "syn 2.0.119",
-]
-
 [[package]]
 name = "dasp_sample"
 version = "0.11.0"
@@ -849,29 +773,6 @@ dependencies = [
  "syn 3.0.6",
 ]
 
-[[package]]
-name = "derive_more"
-version = "2.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d751e9e49156b02b44f9c1815bcb94b984cdcc4396ecc32521c739452808b134"
-dependencies = [
- "derive_more-impl",
-]
-
-[[package]]
-name = "derive_more-impl"
-version = "2.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "799a97264921d8623a957f6c3b9011f3b5492f557bbb7a5a19b7fa6d06ba8dcb"
-dependencies = [
- "convert_case",
- "proc-macro2",
- "quote",
- "rustc_version",
- "syn 2.0.119",
- "unicode-xid",
-]
-
 [[package]]
 name = "digest"
 version = "0.10.7"
@@ -958,15 +859,6 @@ version = "0.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "edd0f118536f44f5ccd48bcb8b111bdc3de888b58c74639dfb034a357d0f206d"
 
-[[package]]
-name = "ena"
-version = "0.14.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eabffdaee24bd1bf95c5ef7cec31260444317e72ea56c4c91750e8b7ee58d5f1"
-dependencies = [
- "log",
-]
-
 [[package]]
 name = "encoding_rs"
 version = "0.8.42"
@@ -1230,58 +1122,6 @@ version = "0.30.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "19fc433e8437a212d1b6f1e68c7824af3aed907da60afa994e7f542d18d12aa9"
 
-[[package]]
-name = "glsl-lang"
-version = "0.8.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "983a18d0c2ecad18ac9ff3c94b069d6bd03b47405a200836d9d8d63def8e34de"
-dependencies = [
- "glsl-lang-lexer",
- "glsl-lang-types",
- "lalrpop",
- "lalrpop-util",
- "lang-util",
- "once_cell",
- "thiserror 2.0.21",
-]
-
-[[package]]
-name = "glsl-lang-lexer"
-version = "0.8.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "abdbc0bdfbc81d557f4865e695457eb23d68031bfb061fda3444f56511b26eee"
-dependencies = [
- "glsl-lang-pp",
- "glsl-lang-types",
- "lalrpop-util",
- "lang-util",
- "thiserror 2.0.21",
-]
-
-[[package]]
-name = "glsl-lang-pp"
-version = "0.8.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "88677876fb27f116015d0ecebda6d77bdf65f3a6fa3f5dfeed10b8c8f04cb2c5"
-dependencies = [
- "arrayvec",
- "derive_more",
- "lang-util",
- "string_cache",
- "string_cache_codegen",
- "thiserror 2.0.21",
-]
-
-[[package]]
-name = "glsl-lang-types"
-version = "0.8.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bd8b1532b424d40df634cf2dc2be56d59f994b9ac07fa7c1e3183fd33db9cb07"
-dependencies = [
- "lang-util",
- "thiserror 2.0.21",
-]
-
 [[package]]
 name = "gpu-allocator"
 version = "0.28.0"
@@ -1428,7 +1268,7 @@ dependencies = [
  "horizon-mods",
  "horizon-protocol",
  "horizon-server-files",
- "horizon-shaderpack",
+ "horizon-shaders",
  "horizon-telemetry",
  "horizon-theme",
  "horizon-threads",
@@ -1441,9 +1281,9 @@ dependencies = [
  "rustix 1.1.5",
  "serde",
  "serde_json",
+ "sha1",
  "sha2",
  "symphonia",
- "toml",
  "ureq",
  "wgpu",
  "winit",
@@ -1478,7 +1318,7 @@ dependencies = [
  "serde",
  "serde_json",
  "sha2",
- "socket2",
+ "socket2 0.5.10",
  "spake2",
 ]
 
@@ -1494,8 +1334,10 @@ name = "horizon-mods"
 version = "0.1.0"
 dependencies = [
  "log",
+ "minisign-verify",
  "serde",
  "serde_json",
+ "sha2",
  "toml",
  "wasmtime",
  "wit-component 0.239.0",
@@ -1541,6 +1383,7 @@ dependencies = [
  "getrandom 0.3.4",
  "horizon-core",
  "horizon-world",
+ "ipconfig",
  "serde_json",
  "sha1",
  "sha2",
@@ -1595,12 +1438,24 @@ dependencies = [
 ]
 
 [[package]]
-name = "horizon-shaderpack"
+name = "horizon-shader-api"
 version = "0.1.0"
 dependencies = [
- "glsl-lang",
+ "bytemuck",
+ "naga",
+ "serde",
+ "serde_json",
+ "sha2",
+ "toml",
+ "zip",
+]
+
+[[package]]
+name = "horizon-shaders"
+version = "0.1.0"
+dependencies = [
+ "horizon-core",
  "naga",
- "pp-rs",
  "zip",
 ]
 
@@ -1755,12 +1610,6 @@ version = "2.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3d3067d79b975e8844ca9eb072e16b31c3c1c36928edf9c6789548c524d0d954"
 
-[[package]]
-name = "ident_case"
-version = "1.0.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b9e0384b61958566e926dc50660321d12159025e767c18e043daf26b70104c39"
-
 [[package]]
 name = "idna"
 version = "1.1.0"
@@ -1833,6 +1682,19 @@ dependencies = [
  "generic-array",
 ]
 
+[[package]]
+name = "ipconfig"
+version = "0.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4d40460c0ce33d6ce4b0630ad68ff63d6661961c48b6dba35e5a4d81cfb48222"
+dependencies = [
+ "socket2 0.6.5",
+ "widestring",
+ "windows-registry",
+ "windows-result 0.4.1",
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "itertools"
 version = "0.14.0"
@@ -1943,73 +1805,6 @@ dependencies = [
  "wasm-bindgen",
 ]
 
-[[package]]
-name = "keccak"
-version = "0.1.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cb26cec98cce3a3d96cbb7bced3c4b16e3d13f27ec56dbd62cbc8f39cfb9d653"
-dependencies = [
- "cpufeatures",
-]
-
-[[package]]
-name = "lalrpop"
-version = "0.22.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ba4ebbd48ce411c1d10fb35185f5a51a7bfa3d8b24b4e330d30c9e3a34129501"
-dependencies = [
- "ascii-canvas",
- "bit-set 0.8.0",
- "ena",
- "itertools",
- "lalrpop-util",
- "petgraph 0.7.1",
- "pico-args",
- "regex",
- "regex-syntax",
- "sha3",
- "string_cache",
- "term",
- "unicode-xid",
- "walkdir",
-]
-
-[[package]]
-name = "lalrpop-util"
-version = "0.22.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b5baa5e9ff84f1aefd264e6869907646538a52147a755d494517a8007fb48733"
-dependencies = [
- "regex-automata",
- "rustversion",
-]
-
-[[package]]
-name = "lang-util"
-version = "0.8.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d1715a1e56998f119cd6d49ac8a69802dcbe4fca96d8291243d6dae87abeb913"
-dependencies = [
- "derive_more",
- "lalrpop-util",
- "lang-util-derive",
- "line-span",
- "smol_str 0.3.6",
- "text-size",
-]
-
-[[package]]
-name = "lang-util-derive"
-version = "0.8.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1f2acc66aedf0e445534e0a6b3f0f6ee20ef6ebb9647dbe10735e52ea8d6a096"
-dependencies = [
- "darling",
- "proc-macro2",
- "quote",
- "syn 2.0.119",
-]
-
 [[package]]
 name = "lazy_static"
 version = "1.5.1"
@@ -2066,12 +1861,6 @@ dependencies = [
  "pkg-config",
 ]
 
-[[package]]
-name = "line-span"
-version = "0.1.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "29fc123b2f6600099ca18248f69e3ee02b09c4188c0d98e9a690d90dec3e408a"
-
 [[package]]
 name = "linux-raw-sys"
 version = "0.4.15"
@@ -2150,6 +1939,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "minisign-verify"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "871285dc19d8d0ebe0eef3d0e99a205f2a71363b122632cbbfa4a6c370a960ce"
+
 [[package]]
 name = "miniz_oxide"
 version = "0.8.9"
@@ -2183,7 +1978,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a616d2fb8c89516ac2723a581f69d6c18576046bed761bd6b305e5618e6ae130"
 dependencies = [
  "arrayvec",
- "bit-set 0.10.0",
+ "bit-set",
  "bitflags 2.13.2",
  "cfg-if",
  "cfg_aliases",
@@ -2245,12 +2040,6 @@ dependencies = [
  "jni-sys 0.3.1",
 ]
 
-[[package]]
-name = "new_debug_unreachable"
-version = "1.0.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "650eef8c711430f1a879fdd01d4745a7deea475becfb90269c06775983bbf086"
-
 [[package]]
 name = "nix"
 version = "0.31.3"
@@ -2750,16 +2539,6 @@ version = "2.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9b4f627cb1b25917193a259e49bdad08f671f8d9708acfd5fe0a8c1455d87220"
 
-[[package]]
-name = "petgraph"
-version = "0.7.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3672b37090dbd86368a4145bc067582552b29c27377cad4e0a306c97f9bd7772"
-dependencies = [
- "fixedbitset",
- "indexmap",
-]
-
 [[package]]
 name = "petgraph"
 version = "0.8.3"
@@ -2771,31 +2550,6 @@ dependencies = [
  "indexmap",
 ]
 
-[[package]]
-name = "phf_generator"
-version = "0.11.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3c80231409c20246a13fddb31776fb942c38553c51e871f8cbd687a4cfb5843d"
-dependencies = [
- "phf_shared",
- "rand",
-]
-
-[[package]]
-name = "phf_shared"
-version = "0.11.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "67eabc2ef2a60eb7faa00097bd1ffdb5bd28e62bf39990626a582201b7a754e5"
-dependencies = [
- "siphasher",
-]
-
-[[package]]
-name = "pico-args"
-version = "0.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5be167a7af36ee22fe3115051bc51f6e6c7054c9348e28deb4f49bd6f705a315"
-
 [[package]]
 name = "pin-project"
 version = "1.1.13"
@@ -2923,12 +2677,6 @@ dependencies = [
  "unicode-xid",
 ]
 
-[[package]]
-name = "precomputed-hash"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "925383efa346730478fb4838dbe9137d2a47675ad789c546d150a6e1dd4ab31c"
-
 [[package]]
 name = "presser"
 version = "0.3.1"
@@ -3022,15 +2770,6 @@ version = "6.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f8dcc9c7d52a811697d2151c701e0d08956f92b0e24136cf4cf27b57a6a0d9bf"
 
-[[package]]
-name = "rand"
-version = "0.8.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e058c7de0b26af77780c769414d6257830bb240f3c38477dbc2c16e5f54d6d4c"
-dependencies = [
- "rand_core",
-]
-
 [[package]]
 name = "rand_core"
 version = "0.6.4"
@@ -3369,16 +3108,6 @@ dependencies = [
  "digest",
 ]
 
-[[package]]
-name = "sha3"
-version = "0.10.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "77fd7028345d415a4034cf8777cd4f8ab1851274233b45f84e3d955502d93874"
-dependencies = [
- "digest",
- "keccak",
-]
-
 [[package]]
 name = "shlex"
 version = "2.0.1"
@@ -3407,12 +3136,6 @@ version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e3a9fe34e3e7a50316060351f37187a3f546bce95496156754b601a5fa71b76e"
 
-[[package]]
-name = "siphasher"
-version = "1.0.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "33f4fe9184a62d842c9ef383018f3306d8ba224fd9d836f56d7288308847c256"
-
 [[package]]
 name = "slab"
 version = "0.4.12"
@@ -3462,16 +3185,6 @@ dependencies = [
  "serde",
 ]
 
-[[package]]
-name = "smol_str"
-version = "0.3.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4aaa7368fcf4852a4c2dd92df0cace6a71f2091ca0a23391ce7f3a31833f1523"
-dependencies = [
- "borsh",
- "serde_core",
-]
-
 [[package]]
 name = "socket2"
 version = "0.5.10"
@@ -3482,6 +3195,16 @@ dependencies = [
  "windows-sys 0.52.0",
 ]
 
+[[package]]
+name = "socket2"
+version = "0.6.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3d1e2c7f27f8d4cb10542a02c49005dbd6e93095799d6f3be745fae9f8fedd4"
+dependencies = [
+ "libc",
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "spake2"
 version = "0.4.0"
@@ -3521,37 +3244,6 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6637bab7722d379c8b41ba849228d680cc12d0a45ba1fa2b48f2a30577a06731"
 
-[[package]]
-name = "string_cache"
-version = "0.8.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bf776ba3fa74f83bf4b63c3dcbbf82173db2632ed8452cb2d891d33f459de70f"
-dependencies = [
- "new_debug_unreachable",
- "parking_lot",
- "phf_shared",
- "precomputed-hash",
- "serde",
-]
-
-[[package]]
-name = "string_cache_codegen"
-version = "0.5.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c711928715f1fe0fe509c53b43e993a9a557babc2d0a3567d0a3006f1ac931a0"
-dependencies = [
- "phf_generator",
- "phf_shared",
- "proc-macro2",
- "quote",
-]
-
-[[package]]
-name = "strsim"
-version = "0.11.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
-
 [[package]]
 name = "subtle"
 version = "2.6.1"
@@ -3668,15 +3360,6 @@ version = "0.13.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "adb6935a6f5c20170eeceb1a3835a49e12e19d792f6dd344ccc76a985ca5a6ca"
 
-[[package]]
-name = "term"
-version = "1.2.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d8c27177b12a6399ffc08b98f76f7c9a1f4fe9fc967c784c5a071fa8d93cf7e1"
-dependencies = [
- "windows-sys 0.61.2",
-]
-
 [[package]]
 name = "termcolor"
 version = "1.4.1"
@@ -3686,12 +3369,6 @@ dependencies = [
  "winapi-util",
 ]
 
-[[package]]
-name = "text-size"
-version = "1.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f18aa187839b2bdb1ad2fa35ead8c4c2976b64e4363c386d45ac0f7ee85c9233"
-
 [[package]]
 name = "thiserror"
 version = "1.0.69"
@@ -3852,7 +3529,7 @@ checksum = "b8765b90061cba6c22b5831f675da109ae5561588290f9fa2317adab2714d5a6"
 dependencies = [
  "memchr",
  "nom",
- "petgraph 0.8.3",
+ "petgraph",
 ]
 
 [[package]]
@@ -3968,10 +3645,6 @@ version = "0.9.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
 
-[[package]]
-name = "voxel-kernels"
-version = "0.1.0"
-
 [[package]]
 name = "walkdir"
 version = "2.5.0"
@@ -4552,6 +4225,7 @@ dependencies = [
  "hashbrown 0.17.1",
  "js-sys",
  "log",
+ "naga",
  "parking_lot",
  "portable-atomic",
  "profiling",
@@ -4573,8 +4247,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "14c018fce9b6270aa203c2fdd56f3cce996713534bd757e4ea58c8560b121f14"
 dependencies = [
  "arrayvec",
- "bit-set 0.10.0",
- "bit-vec 0.9.1",
+ "bit-set",
+ "bit-vec",
  "bitflags 2.13.2",
  "bytemuck",
  "cfg_aliases",
@@ -4624,7 +4298,7 @@ dependencies = [
  "android_system_properties",
  "arrayvec",
  "ash",
- "bit-set 0.10.0",
+ "bit-set",
  "bitflags 2.13.2",
  "block2 0.6.2",
  "bytemuck",
@@ -4688,6 +4362,12 @@ dependencies = [
  "web-sys",
 ]
 
+[[package]]
+name = "widestring"
+version = "1.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "72069c3113ab32ab29e5584db3c6ec55d416895e60715417b5b883a357c3e471"
+
 [[package]]
 name = "winapi-util"
 version = "0.1.11"
@@ -4820,6 +4500,17 @@ dependencies = [
  "windows-link",
 ]
 
+[[package]]
+name = "windows-registry"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "02752bf7fbdcce7f2a27a742f798510f3e5ad88dbe84871e5168e2120c3d5720"
+dependencies = [
+ "windows-link",
+ "windows-result 0.4.1",
+ "windows-strings",
+]
+
 [[package]]
 name = "windows-result"
 version = "0.1.2"
@@ -5122,7 +4813,7 @@ dependencies = [
  "rustix 0.38.44",
  "sctk-adwaita",
  "smithay-client-toolkit",
- "smol_str 0.2.2",
+ "smol_str",
  "tracing",
  "unicode-segmentation",
  "wasm-bindgen",

Cargo.toml

@@ -1,6 +1,6 @@
 [workspace]
-exclude = ["launcher", "crates/horizon-telemetry-server", "third_party/wgpu-hal"]
-members = ["crates/horizon-core", "crates/horizon-dualsense", "crates/horizon-threads", "crates/horizon-world", "crates/voxel-kernels", "crates/horizon-client", "crates/horizon-server-files", "crates/horizon-server", "crates/horizon-bots", "crates/horizon-assets", "crates/horizon-protocol", "crates/horizon-theme", "crates/horizon-shaderpack", "crates/horizon-prepare", "crates/horizon-telemetry", "crates/horizon-bench", "crates/horizon-friends", "crates/horizon-relay", "crates/horizon-mod-sdk", "crates/horizon-mods", "crates/horizon-mods/tests/guest", "crates/cargo-horizon-mod", "crates/horizon-port-pack", "crates/horizon-release-sign", "crates/horizon-mod-sdk/examples/coords-hud", "xtask"]
+exclude = ["launcher", "crates/horizon-telemetry-server", "crates/horizon-mod-registry", "third_party/wgpu-hal"]
+members = ["crates/horizon-core", "crates/horizon-dualsense", "crates/horizon-threads", "crates/horizon-world", "crates/horizon-client", "crates/horizon-server-files", "crates/horizon-server", "crates/horizon-bots", "crates/horizon-assets", "crates/horizon-protocol", "crates/horizon-theme", "crates/horizon-prepare", "crates/horizon-telemetry", "crates/horizon-bench", "crates/horizon-friends", "crates/horizon-relay", "crates/horizon-mod-sdk", "crates/horizon-mods", "crates/horizon-mods/tests/guest", "crates/cargo-horizon-mod", "crates/horizon-port-pack", "crates/horizon-shaders", "crates/horizon-shader-api", "crates/horizon-release-sign", "crates/horizon-mod-sdk/examples/coords-hud", "xtask"]
 resolver = "2"
 
 [workspace.package]

README.md

@@ -16,6 +16,7 @@
   <a href="#download"><b>Download</b></a> ·
   <a href="https://playhorizon.dev/docs/"><b>Documentation</b></a> ·
   <a href="https://github.com/ludovic111/horizon/releases"><b>Release notes</b></a> ·
+  <a href="ROADMAP.md"><b>Roadmap</b></a> ·
   <a href="#project-status"><b>Project status</b></a> ·
   <a href="#contributing"><b>Contributing</b></a>
 </p>
@@ -45,7 +46,7 @@ The [documentation](https://playhorizon.dev/docs/) covers each of these.
 
 - **The game:** singleplayer with vanilla's world generation, mobs, villagers, raids, redstone, every command, the HUD and the recipe book, on saves in vanilla's format. Worlds from 1.8 to 26.2 are upgraded as vanilla does. [Status table](#project-status).
 - **Horizon's own extras:** new menus (vanilla's are one setting away), graphics presets, distant terrain up to 1024 chunks, controller support, optional zoom, minimap and more, all off by default where they would change the vanilla look. See [Settings](https://playhorizon.dev/docs/settings).
-- **Resource packs, shader packs and data packs:** resource packs work, Java shader packs run their full-screen effects (experimental), and data packs load functions, predicates and item modifiers.
+- **Resource packs and data packs:** resource packs work, and data packs load functions, predicates and item modifiers.
 - **Playing with others:** invite friends from the pause menu's Friends button with a code, Open to LAN, and joining offline-mode servers. Horizon cannot sign in to a Microsoft account yet, so it cannot join servers that check accounts. See [Multiplayer](https://playhorizon.dev/docs/multiplayer).
 - **Mods:** Horizon has its own mod system (Rust compiled to WebAssembly). Java mod jars do not run. See [Mods and data packs](https://playhorizon.dev/docs/mods).
 
@@ -57,7 +58,7 @@ Screenshots, captured in the Rust client itself with vanilla assets and no mods
   </tr>
   <tr>
     <td width="50%"><img src="docs/media/survival.webp" alt="Survival at dusk: a zombie walks up, with the hotbar, health, hunger and experience"></td>
-    <td width="50%"><img src="docs/media/settings.webp" alt="Vanilla's Video Settings screen with Horizon's own buttons at the top: Horizon Graphics, Advanced Graphics and Shader Packs"></td>
+    <td width="50%"><img src="docs/media/settings.webp" alt="Vanilla's Video Settings screen with Horizon's own buttons at the top: Horizon Graphics and Advanced Graphics"></td>
   </tr>
   <tr>
     <td width="50%"><img src="docs/media/village.webp" alt="A plains village among savanna hills, with farms, villagers and an iron golem"></td>
@@ -109,6 +110,10 @@ Everything prepared lands in the gitignored `.local/`. It is derived from the ga
 
 The client starts on the title screen. Command-line options (`--world`, `--seed`, `--creative`, `--render-distance`, `--dedicated`), controls, scripting through `horizon-ctl` and the architecture are described in [the native client guide](docs/native-client.md). The rest of the developer documentation is indexed in [docs/README.md](docs/README.md), including [the parity workflow](docs/parity-workflow.md).
 
+## Roadmap
+
+What is being done now, what comes next and where you can help, in plain words and in technical detail: [ROADMAP.md](ROADMAP.md). [playhorizon.dev/hub](https://playhorizon.dev/hub) shows it with the work board, the journal of what shipped and how to help.
+
 ## Contributing
 
 Issues and pull requests are welcome: see [CONTRIBUTING.md](CONTRIBUTING.md) for how we work (vanilla first, small pull requests, labels), or [the contributing guide](https://playhorizon.dev/docs/contributing) on the site. Questions and ideas: [Discord](https://discord.gg/HcTeMZxe5E). Before opening a pull request, run the self-check and paste the block it prints:

ROADMAP.md

@@ -0,0 +1,341 @@
+# Horizon roadmap
+
+<!-- Generated by tools/roadmap.py from roadmap/roadmap.toml: edit that file, then run `python3 tools/roadmap.py build`. -->
+
+What is being done on Horizon, what comes next and where you can help. There are no dates: things are Now, Next or Later. Each item is said in plain words, with the technical picture folded under it. The same roadmap, with a Simple / Technical switch, the board, the journal and how to help, is on [playhorizon.dev/hub](https://playhorizon.dev/hub). Pull requests carry the `roadmap:<id>` label of their item.
+
+## At a glance
+
+Horizon is Minecraft: Java Edition 26.3 rewritten from scratch in Rust, so it runs faster on the same computer. Single player, LAN, servers, resource packs and Horizon's own mods work today, on your own copy of the game.
+
+**Being done now**
+
+- **Steady frames at long render distances**: Making Horizon faster than vanilla on every computer, with smooth camera movement even at 32 chunks, by spreading the work better over the processor's cores.
+- **Modpacks' world generation, natively**: Making the world-generation mods of popular modpacks (new structures, YUNG's dungeons and mineshafts, packs built on Lithostitched) generate their worlds in Horizon, natively and fast.
+- **Playing on servers: everything shows as it should**: When you play on a server, other players, mobs, items and menus look and behave as in vanilla: skins, poses, item names, inventories and server networks.
+- **Single player as a server: the last differences**: Single player now runs a small server in the background, as vanilla does. We are fixing what still behaves differently there; every fix also works for LAN and server players.
+- **Horizon's mod registry**: One place for mods, modpacks and resource packs made for Horizon: browse them on the website and install them from the launcher in one click.
+
+**Next**: Microsoft sign-in (coming soon); CurseForge in the mod browser (coming soon); Fresh benchmarks against vanilla; Pistons push players and mobs; Horizon on Intel Macs.
+
+**How to help**: Play it and tell us what differs from vanilla (Discord or GitHub), run the benchmark on your computer, vote for what you want next, or pick one of the Help wanted items.
+
+**Developers**: Read CONTRIBUTING.md, pick a Help wanted item or a To do card, check vanilla's code for the behaviour, and paste the block `python3 tools/pr_ready.py` prints in your pull request.
+
+## Now
+
+### Performance
+
+#### Steady frames at long render distances
+
+Making Horizon faster than vanilla on every computer, with smooth camera movement even at 32 chunks, by spreading the work better over the processor's cores.
+
+<details><summary>Technical</summary>
+
+Frame pacing at render distance 32 ([#678](https://github.com/ludovic111/horizon/issues/678)): long frames come from work competing with the render thread. In review: world generation workers build free structure starts instead of queueing them ([#1760](https://github.com/ludovic111/horizon/issues/1760)), the worker pool leaves one core as vanilla does ([#1778](https://github.com/ludovic111/horizon/issues/1778)), and the terrain vertex arena is read as storage where flat draws run ([#1742](https://github.com/ludovic111/horizon/issues/1742)). Still open: far terrain at 48 to 64 chunks ([#718](https://github.com/ludovic111/horizon/issues/718)) and CPU-bound fields of block entities ([#717](https://github.com/ludovic111/horizon/issues/717)). Every change shows before and after numbers from `tools/perf_bench.py` against vanilla 26.3 ([docs/benchmark.md](docs/benchmark.md)).
+
+</details>
+
+#### Faster block lookups
+
+Speeding up the code that reads and writes the blocks of the world, which almost everything in the game goes through: generation, lighting, meshing and ticking.
+
+<details><summary>Technical</summary>
+
+`PalettedContainer` and `PackedStorage` find an entry's word by multiply and shift instead of an integer division ([#1790](https://github.com/ludovic111/horizon/issues/1790), [#1794](https://github.com/ludovic111/horizon/issues/1794)); meshing looks up baked models by index, not by name ([#1747](https://github.com/ludovic111/horizon/issues/1747)). Each change keeps the paletted storage harnesses identical and shows its microbenchmark ([docs/performance/paletted-container-access-results.md](docs/performance/paletted-container-access-results.md)).
+
+</details>
+
+### Modpacks
+
+#### Modpacks' world generation, natively
+
+Making the world-generation mods of popular modpacks (new structures, YUNG's dungeons and mineshafts, packs built on Lithostitched) generate their worlds in Horizon, natively and fast.
+
+<details><summary>Technical</summary>
+
+`horizon-port-pack` carries a pack's data-driven content over; structure mods that need code get a native port: YUNG's worldgen as written ([#1746](https://github.com/ludovic111/horizon/issues/1746)), Lithostitched's limited and guaranteed elements with pool and processor modifiers ([#1777](https://github.com/ludovic111/horizon/issues/1777)), its processors as the game's own types ([#1765](https://github.com/ludovic111/horizon/issues/1765)). Proved by the structure blocks and layout harnesses ([#1753](https://github.com/ludovic111/horizon/issues/1753), [#1757](https://github.com/ludovic111/horizon/issues/1757)). Mods whose Java code does more than world generation don't run ([docs/modpacks.md](docs/modpacks.md)).
+
+</details>
+
+### Servers and multiplayer
+
+#### Playing on servers: everything shows as it should
+
+When you play on a server, other players, mobs, items and menus look and behave as in vanilla: skins, poses, item names, inventories and server networks.
+
+<details><summary>Technical</summary>
+
+Client-of-a-server fixes in `game/remote*.rs` and `horizon-protocol`: mobs' aggressive and item-use flags ([#1802](https://github.com/ludovic111/horizon/issues/1802), [#1798](https://github.com/ludovic111/horizon/issues/1798)), ghost items after a remote menu ([#1795](https://github.com/ludovic111/horizon/issues/1795)), skins ([#1652](https://github.com/ludovic111/horizon/issues/1652)), cookies and transfer packets for proxy networks ([#1650](https://github.com/ludovic111/horizon/issues/1650)), firework boosts ([#1671](https://github.com/ludovic111/horizon/issues/1671)), living-entity attributes and simulation distance ([#1731](https://github.com/ludovic111/horizon/issues/1731)), styled item names ([#1702](https://github.com/ludovic111/horizon/issues/1702)), primed TNT between updates ([#1710](https://github.com/ludovic111/horizon/issues/1710)).
+
+</details>
+
+#### Server dialogs and login screens
+
+Servers that show dialogs, such as the register and login screens of AuthMe, will work in Horizon.
+
+<details><summary>Technical</summary>
+
+26.3's dialog packets and model ([#1720](https://github.com/ludovic111/horizon/issues/1720)), the dialog screen with its buttons and actions ([#1734](https://github.com/ludovic111/horizon/issues/1734)), then text and boolean inputs ([#1735](https://github.com/ludovic111/horizon/issues/1735)).
+
+</details>
+
+### Mods and API
+
+#### Horizon's mod registry
+
+One place for mods, modpacks and resource packs made for Horizon: browse them on the website and install them from the launcher in one click.
+
+<details><summary>Technical</summary>
+
+Merged: the registry index (schema 1, `.hpack`, checks before install, [#1634](https://github.com/ludovic111/horizon/issues/1634)), `cargo horizon-mod check` ([#1642](https://github.com/ludovic111/horizon/issues/1642)) and the submission service (`crates/horizon-mod-registry`, [#1659](https://github.com/ludovic111/horizon/issues/1659)). In review: the website's /mods ([#1596](https://github.com/ludovic111/horizon/issues/1596)) and /mods/submit ([#1635](https://github.com/ludovic111/horizon/issues/1635)), and in the launcher the registry as a source ([#1636](https://github.com/ludovic111/horizon/issues/1636)), install, enable and takedowns ([#1637](https://github.com/ludovic111/horizon/issues/1637)), the Mods page ([#1638](https://github.com/ludovic111/horizon/issues/1638)) and modpacks as their own profiles ([#1640](https://github.com/ludovic111/horizon/issues/1640)).
+
+More: [docs/mods.md](docs/mods.md)
+
+</details>
+
+### Gameplay parity
+
+#### Single player as a server: the last differences
+
+Single player now runs a small server in the background, as vanilla does. We are fixing what still behaves differently there; every fix also works for LAN and server players.
+
+<details><summary>Technical</summary>
+
+Since [#1514](https://github.com/ludovic111/horizon/issues/1514) single player runs on the server thread (`game/integrated.rs`) and the window joins it as a client; `--in-frame` keeps the old path. The open `[server-thread]` issues list the gaps. In review: a tool that changes a block ends the click ([#1797](https://github.com/ludovic111/horizon/issues/1797)), potions keep their potion over the connection ([#1796](https://github.com/ludovic111/horizon/issues/1796)), mobs' aggression and arm swings ([#1802](https://github.com/ludovic111/horizon/issues/1802)). [docs/server-levels.md](docs/server-levels.md).
+
+</details>
+
+#### Play in your language
+
+Item names, container titles and server messages follow the language you pick, as in vanilla. Today parts of the game stay in English.
+
+<details><summary>Technical</summary>
+
+Translatable components resolved through the selected language for items, containers and server text ([#1806](https://github.com/ludovic111/horizon/issues/1806)), on top of the bundled languages the prepared resources carry ([#1594](https://github.com/ludovic111/horizon/issues/1594)). Left: the client's own screens ([#1672](https://github.com/ludovic111/horizon/issues/1672)) and the main menu with zh_cn ([#1774](https://github.com/ludovic111/horizon/issues/1774)).
+
+</details>
+
+### Rendering
+
+#### Shader packs, written again from scratch
+
+Shader packs were removed and are being rebuilt from scratch. They come back, off by default, once the best-known packs draw properly.
+
+<details><summary>Technical</summary>
+
+A clean-room rewrite in `horizon-shaderpack`, from the packs' public format documentation only: reading packs, the preprocessor and `.properties` files are merged ([#1584](https://github.com/ludovic111/horizon/issues/1584), [#1585](https://github.com/ludovic111/horizon/issues/1585), [#1586](https://github.com/ludovic111/horizon/issues/1586)); translating programs to WGSL through naga, buffers, uniforms and the terrain, entity, sky, weather and hand stages are in review ([#1698](https://github.com/ludovic111/horizon/issues/1698) to [#1801](https://github.com/ludovic111/horizon/issues/1801)).
+
+More: [#1561](https://github.com/ludovic111/horizon/issues/1561) · [#1771](https://github.com/ludovic111/horizon/issues/1771) · [#1786](https://github.com/ludovic111/horizon/issues/1786)
+
+</details>
+
+### Horizon extras
+
+#### Discord Rich Presence
+
+Your Discord profile can show that you are playing Horizon, with a switch to turn it off.
+
+<details><summary>Technical</summary>
+
+A Discord IPC client on its own thread ([#1787](https://github.com/ludovic111/horizon/issues/1787)) and the presence with its setting ([#1788](https://github.com/ludovic111/horizon/issues/1788)). Merged: it ships with the next release.
+
+</details>
+
+### Code and tools
+
+#### A leaner codebase that builds faster
+
+Cleaning up Horizon's code: removing what nothing uses and making it quicker to build, so fixes and new features land faster.
+
+<details><summary>Technical</summary>
+
+A review of the whole tree: dead code and stubs removed ([#1432](https://github.com/ludovic111/horizon/issues/1432), [#1658](https://github.com/ludovic111/horizon/issues/1658)), one probe binary per crate ([#1453](https://github.com/ludovic111/horizon/issues/1453), [#1454](https://github.com/ludovic111/horizon/issues/1454)), shared harness helpers ([#1448](https://github.com/ludovic111/horizon/issues/1448)), clippy clean on the whole tree ([#1707](https://github.com/ludovic111/horizon/issues/1707)). [docs/architecture.md](docs/architecture.md) maps each feature to its files and harnesses.
+
+</details>
+
+## Next
+
+### Performance
+
+#### Fresh benchmarks against vanilla
+
+New public numbers comparing Horizon with vanilla on many kinds of computers, measured the same way every time, on the website's Benchmarks page.
+
+<details><summary>Technical</summary>
+
+Redo the comparison after the current performance work ([#1073](https://github.com/ludovic111/horizon/issues/1073)); reliability, coverage and presentation ([#1346](https://github.com/ludovic111/horizon/issues/1346)); a scene must count as loaded only once its first chunk arrives ([#1749](https://github.com/ludovic111/horizon/issues/1749)). Players' reports come in through `--benchmark` and `horizon-launcher data benchmark` ([docs/benchmark.md](docs/benchmark.md)).
+
+</details>
+
+### Modpacks
+
+#### CurseForge in the mod browser (coming soon)
+
+Coming soon: search and download CurseForge mods and modpacks from the launcher, as you can with Modrinth today.
+
+<details><summary>Technical</summary>
+
+The mod browser lists CurseForge as coming soon ([docs/mod-browser.md](docs/mod-browser.md)): it needs CurseForge API access. Meanwhile packs import from a CurseForge zip or instance folder, and jars only CurseForge hosts come from the player's own instance ([docs/modpacks.md](docs/modpacks.md)).
+
+</details>
+
+### Gameplay parity
+
+#### Pistons push players and mobs
+
+Pistons and slime blocks will push players, mobs and items as in vanilla. Today moving blocks pass through them.
+
+<details><summary>Technical</summary>
+
+Port `PistonMovingBlockEntity.moveCollidedEntities` and `moveStuckEntities` (honey), the slime bounce and `Entity.limitPistonMovement` for `MoverType.PISTON`, in single player and for a server's players. Issues [#1496](https://github.com/ludovic111/horizon/issues/1496), [#1609](https://github.com/ludovic111/horizon/issues/1609), [#1608](https://github.com/ludovic111/horizon/issues/1608), [#1704](https://github.com/ludovic111/horizon/issues/1704), [#1758](https://github.com/ludovic111/horizon/issues/1758).
+
+</details>
+
+### Launcher
+
+#### Microsoft sign-in (coming soon)
+
+Coming soon: sign in with your Microsoft account to play on online-mode servers. The code is ready; it waits for Microsoft's approval.
+
+<details><summary>Technical</summary>
+
+Device-code sign-in in the launcher and online-mode login in the client ([docs/microsoft-account.md](docs/microsoft-account.md)). It is turned on by setting the app's client id once Minecraft API access is approved; until then the launcher shows "Coming soon".
+
+More: [#1270](https://github.com/ludovic111/horizon/issues/1270)
+
+</details>
+
+#### Horizon on Intel Macs
+
+Builds of the game and the launcher for Macs with an Intel processor.
+
+<details><summary>Technical</summary>
+
+x86_64 game and launcher builds, picked per processor ([#1171](https://github.com/ludovic111/horizon/issues/1171)). Before it ships it needs a run on a real Intel Mac: Rosetta on Apple Silicon only proves the CPU code. Requests: [#1161](https://github.com/ludovic111/horizon/issues/1161), [#1792](https://github.com/ludovic111/horizon/issues/1792).
+
+</details>
+
+## Later
+
+### Gameplay parity
+
+#### Following new Minecraft versions
+
+When Mojang releases a new version of the game, Horizon follows it, and every system is checked against the new version again.
+
+<details><summary>Technical</summary>
+
+The port pipeline detects a release, diffs its classes against 26.3 and writes a port report ([docs/version-ports.md](docs/version-ports.md)); the harnesses then run against the new version.
+
+</details>
+
+### Horizon extras
+
+#### An optional AI teammate
+
+An AI teammate that plays beside you and that you can talk to. It is off unless you turn it on, and the No AI switch hides it completely.
+
+<details><summary>Technical</summary>
+
+Draft pull requests: the companion ([#1068](https://github.com/ludovic111/horizon/issues/1068)), its safety modes and their evaluation ([#1069](https://github.com/ludovic111/horizon/issues/1069)), and a route that finishes the game ([#1070](https://github.com/ludovic111/horizon/issues/1070)). Local models first; it ships only once the safety evaluation passes.
+
+</details>
+
+## Help wanted
+
+### Performance
+
+#### Benchmark your computer
+
+Run Horizon's built-in benchmark and share the report: every new computer makes the performance work more accurate. No coding needed.
+
+<details><summary>Technical</summary>
+
+`horizon-launcher play --arg=--benchmark --arg=standard` writes a JSON report; `horizon-launcher data benchmark <report>` shows what would be sent and uploads it ([website/docs/performance.md](website/docs/performance.md)). Results from three installs with the same hardware appear on the Benchmarks page. Example: [#1711](https://github.com/ludovic111/horizon/issues/1711).
+
+</details>
+
+### Gameplay parity
+
+#### End city banners keep their pattern
+
+Banners in End cities show as plain magenta instead of with their pattern.
+
+<details><summary>Technical</summary>
+
+Compare the banner block entities the End city templates place with vanilla's (`EndCityPieces`, the templates' block entity NBT, `BannerBlockEntity`'s patterns), in `crates/horizon-world/src/worldgen/structure/`. Issue [#1438](https://github.com/ludovic111/horizon/issues/1438); possibly related: [#526](https://github.com/ludovic111/horizon/issues/526).
+
+</details>
+
+#### Enchanted loot in End cities
+
+Armour and tools in End city chests should come enchanted, as in vanilla.
+
+<details><summary>Technical</summary>
+
+`loot.rs` implements `enchant_with_levels`: find why the End city chest table's rolls come out bare, and compare them with vanilla's for a few seeds. Issues [#1437](https://github.com/ludovic111/horizon/issues/1437), [#1660](https://github.com/ludovic111/horizon/issues/1660).
+
+</details>
+
+#### Cooldowns drawn on items
+
+After you throw an ender pearl, its slot should show the cooldown sweeping away, as in vanilla.
+
+<details><summary>Technical</summary>
+
+Vanilla draws `ItemCooldowns`' percent as a white overlay over the slot (`GuiGraphicsExtractor.itemDecorations` and `itemCooldown`) in the hotbar and in inventories. Issue [#1763](https://github.com/ludovic111/horizon/issues/1763).
+
+</details>
+
+#### Chat settings and team prefixes
+
+The Hidden and Commands Only chat settings should hide chat, and team prefixes should appear before names in chat.
+
+<details><summary>Technical</summary>
+
+Vanilla checks `ChatVisiblity` before it delivers chat and system messages ([#1376](https://github.com/ludovic111/horizon/issues/1376)), and chat uses the team-formatted display name ([#1378](https://github.com/ludovic111/horizon/issues/1378)). Both issues have exact steps to reproduce.
+
+</details>
+
+#### A pointing hand over buttons
+
+The mouse pointer should turn into a pointing hand over menu buttons, as in vanilla 26.3.
+
+<details><summary>Technical</summary>
+
+26.3's `AbstractWidget` asks for a cursor from `CursorTypes` when it is hovered; winit's `CursorIcon::Pointer` gives the same shape. Issue [#1347](https://github.com/ludovic111/horizon/issues/1347).
+
+</details>
+
+#### Ctrl+Backspace and scroll bars in menus
+
+Ctrl+Backspace should delete a whole word in the creative search, and every list's scroll bar should be draggable.
+
+<details><summary>Technical</summary>
+
+`EditBox` deletes by word with Ctrl ([#1764](https://github.com/ludovic111/horizon/issues/1764)); the Game Rules and Statistics lists' scroll bars can't be dragged ([#1782](https://github.com/ludovic111/horizon/issues/1782), after [#978](https://github.com/ludovic111/horizon/issues/978)).
+
+</details>
+
+#### Chickens flap while they fall
+
+Chickens should flap their wings while they fall, not stand still in the air.
+
+<details><summary>Technical</summary>
+
+Vanilla's `Chicken.aiStep` updates `flap` and `flapSpeed` when the chicken isn't on the ground, and the model's wings follow them. Issue [#1706](https://github.com/ludovic111/horizon/issues/1706).
+
+</details>
+
+## Recently shipped
+
+- **Server resource packs** (v0.2.48): Servers can send you their resource pack: Horizon asks, downloads it and applies it, like vanilla. [#1562](https://github.com/ludovic111/horizon/issues/1562) · [#1569](https://github.com/ludovic111/horizon/issues/1569) · [#1570](https://github.com/ludovic111/horizon/issues/1570)
+- **Single player on its own server thread** (v0.2.39): Single player runs on a server thread, as vanilla does, so the world keeps ticking smoothly while the window draws. [#1514](https://github.com/ludovic111/horizon/issues/1514) · [docs/server-levels.md](docs/server-levels.md)
+- **GPU occlusion culling on Macs** (v0.2.17): On Macs the GPU now skips terrain hidden behind hills and caves: 8 to 48% more frames per second at 32 chunks on an M4 Pro. [#1434](https://github.com/ludovic111/horizon/issues/1434)
+- **Animated textures on the GPU** (v0.2.5): Water, lava and other animated blocks are now animated by the graphics card: 1.7 to 2.4 times better 1% lows on Intel graphics. [#1239](https://github.com/ludovic111/horizon/issues/1239)
+- **Far Detail for integrated graphics** (v0.2.5): An optional Reduced setting for far terrain, suggested on integrated graphics, that saves 2 to 4 ms of GPU time per frame. [#1199](https://github.com/ludovic111/horizon/issues/1199) · [#1029](https://github.com/ludovic111/horizon/issues/1029)
+- **The launcher's mod browser** (launcher@0.2.0): Search Modrinth for mods, modpacks and resource packs from the launcher; it says before installing what works in Horizon. [#1154](https://github.com/ludovic111/horizon/issues/1154) · [#1242](https://github.com/ludovic111/horizon/issues/1242) · [#1243](https://github.com/ludovic111/horizon/issues/1243) · [#1246](https://github.com/ludovic111/horizon/issues/1246) · [docs/mod-browser.md](docs/mod-browser.md)
+- **A blocky, Minecraft-like launcher** (launcher@0.2.0): The launcher got a new blocky look in Horizon's purple, in dark and light. [#1269](https://github.com/ludovic111/horizon/issues/1269) · [docs/design-system.md](docs/design-system.md)
+- **Dynamic lights** (v2026.10.22): An optional extra: torches you hold, drop or set on fire light up what is around them. [#1162](https://github.com/ludovic111/horizon/issues/1162)
+- **Host a server from the launcher** (launcher-v0.15.0): The launcher's Servers page creates, starts, backs up and updates a Horizon server with buttons, and invites friends. [#1026](https://github.com/ludovic111/horizon/issues/1026) · [docs/hosting.md](docs/hosting.md)

THIRD_PARTY_NOTICES.md

@@ -1,35 +1,5 @@
 # Third-party notices
 
-## CullLeaves
-
-The optional leaf and mangrove-root face-culling behavior is adapted from
-[CullLeaves](https://github.com/TeamMidnightDust/CullLeaves) by MidnightDust.
-Its MIT license is reproduced below.
-
-```text
-MIT License
-
-Copyright (c) 2020 MidnightDust
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
-```
-
 ## wgpu-hal
 
 `third_party/wgpu-hal` is [wgpu-hal](https://github.com/gfx-rs/wgpu) 30.0.1 by the gfx-rs

benchmarks/server-four-way-2026-10-19/README.md

@@ -131,8 +131,8 @@ average) and reached the ThinkPad over the tailnet.
   It ran with Paper's defaults except `connection-throttle: -1` in `bukkit.yml`. Every bot connects from one
   address, and the default throttle (4 s) refused all but the first. Paperclip patched the pinned server jar
   from its cache. Same Java and heap.
-- Fabric + Lithium: the pinned server jar on Fabric loader 0.19.5 (`packs/fabric.lock.json`) with Lithium
-  `mc26.3-0.26.2-fabric` (`packs/mods.lock.json`, checked against its SHA-512). Lithium needs no Fabric API.
+- Fabric + Lithium: the pinned server jar on Fabric loader 0.19.5 (`tools/benchmark-deps/fabric.lock.json`) with Lithium
+  `mc26.3-0.26.2-fabric` (`tools/benchmark-deps/mods.lock.json`, checked against its SHA-512). Lithium needs no Fabric API.
   Same Java and heap.
 
 The Paper and Fabric jars are dev-only downloads into `.local/server-bench/jars` and are never committed or

crates/cargo-horizon-mod/Cargo.toml

@@ -4,10 +4,10 @@ version = "0.1.0"
 edition.workspace = true
 license.workspace = true
 rust-version = "1.86"
-description = "cargo horizon-mod new/build/run: make Horizon mods in Rust (docs/mods.md)"
+description = "cargo horizon-mod new/build/run/check: make Horizon mods in Rust (docs/mods.md)"
 
 [dependencies]
-horizon-mods = { path = "../horizon-mods", default-features = false, features = ["pack"] }
+horizon-mods = { path = "../horizon-mods", default-features = false, features = ["pack", "runtime", "index"] }
 serde_json = "1.0.151"
 
 [lints]

crates/cargo-horizon-mod/src/check.rs

@@ -0,0 +1,278 @@
+//! `cargo horizon-mod check <file>`: what the registry checks of a submission,
+//! run anywhere: its kind's own checks (docs/api/mod-index.md), its signature
+//! when given a key, and for a mod a trial run in the sandbox: it must start,
+//! survive ticks, frames, a chat line and each of its commands, and import
+//! no more than its capabilities.
+use horizon_mods::{
+    Clock, Mods, Output, Package, Player, Snapshot, Status,
+    index::{self, Facts, Kind},
+    manifest::component_imports,
+};
+use serde_json::{Value, json};
+use std::path::Path;
+
+/// How long the trial run plays: two seconds of game.
+const TICKS: u64 = 40;
+const FRAMES_PER_TICK: u64 = 3;
+
+pub struct Report {
+    pub kind: Kind,
+    pub facts: Facts,
+    pub sha256: String,
+    pub size: u64,
+    pub signed: bool,
+    /// A mod has code to run (a content mod may have none).
+    pub code: bool,
+    /// A mod's component imports.
+    pub imports: Vec<String>,
+    /// A mod's commands, each run once.
+    pub commands: Vec<String>,
+    /// What the mod showed during the trial run.
+    pub output: Vec<String>,
+}
+
+impl Report {
+    pub fn json(&self) -> Value {
+        let requires: Vec<Value> = self
+            .facts
+            .requires
+            .iter()
+            .map(|r| json!({"id": r.id, "version": r.version, "sha256": r.sha256}))
+            .collect();
+        json!({
+            "kind": self.kind.name(),
+            "id": self.facts.id,
+            "version": self.facts.version,
+            "api": self.facts.api,
+            "side": self.facts.side,
+            "capabilities": self.facts.capabilities,
+            "game": self.facts.game,
+            "requires": requires,
+            "sha256": self.sha256,
+            "size": self.size,
+            "signed": self.signed,
+            "code": self.code,
+            "imports": self.imports,
+            "commands": self.commands,
+            "output": self.output,
+        })
+    }
+
+    pub fn text(&self) -> String {
+        let f = &self.facts;
+        let mut out = format!(
+            "{} {} ({}",
+            f.id.as_deref().unwrap_or("resource pack"),
+            f.version.as_deref().unwrap_or(""),
+            self.kind.name()
+        );
+        if let Some(side) = f.side {
+            let side = serde_json::to_value(side).unwrap_or_default();
+            out += &format!(", API {}, {}", f.api, side.as_str().unwrap_or("?"));
+        } else if !f.api.is_empty() {
+            out += &format!(", format {}", f.api);
+        }
+        if let Some(game) = &f.game {
+            out += &format!(", for {game}");
+        }
+        let signed = if self.signed {
+            "signature verified"
+        } else {
+            "unsigned"
+        };
+        out += &format!(
+            ")\n  {} bytes, SHA-256 {}, {signed}\n",
+            self.size, self.sha256
+        );
+        for c in &f.capabilities {
+            out += &format!("  may {}\n", c.describe());
+        }
+        for r in &f.requires {
+            out += &format!("  needs {} {} ({})\n", r.id, r.version, &r.sha256[..12]);
+        }
+        if self.kind == Kind::Mod && !self.code {
+            out += "  no code: content only, nothing to run\n";
+        } else if self.kind == Kind::Mod {
+            let commands = if self.commands.is_empty() {
+                String::new()
+            } else {
+                format!(", /{}", self.commands.join(", /"))
+            };
+            out += &format!(
+                "  trial run: started, {TICKS} ticks, {} frames, a chat line{commands}: ok\n",
+                TICKS * FRAMES_PER_TICK
+            );
+        }
+        out
+    }
+}
+
+/// The kind a file's extension says.
+pub fn kind_of(path: &Path) -> Option<Kind> {
+    match path.extension()?.to_str()? {
+        "hmod" => Some(Kind::Mod),
+        "hpack" => Some(Kind::Modpack),
+        "zip" => Some(Kind::ResourcePack),
+        _ => None,
+    }
+}
+
+/// Checks the file at `path` as `kind`; `key` and `signature` (the
+/// `.minisig` text) check its signature.
+pub fn check(
+    path: &Path,
+    kind: Kind,
+    key: Option<&str>,
+    signature: Option<&str>,
+) -> Result<Report, String> {
+    let size = std::fs::metadata(path)
+        .map_err(|e| format!("{}: {e}", path.display()))?
+        .len();
+    if size > index::MAX_FILE {
+        return Err(format!("over {} MiB", index::MAX_FILE >> 20));
+    }
+    index::open(&kind)?;
+    let facts = index::inspect(&kind, path)?;
+    let signed = match (key, signature) {
+        (Some(key), Some(sig)) => {
+            index::verify_signature(key, sig, path)?;
+            true
+        }
+        (None, None) => false,
+        _ => return Err("--key and --signature go together".into()),
+    };
+    let mut report = Report {
+        kind,
+        facts,
+        sha256: index::sha256_file(path)?,
+        size,
+        signed,
+        code: false,
+        imports: Vec::new(),
+        commands: Vec::new(),
+        output: Vec::new(),
+    };
+    if report.kind == Kind::Mod {
+        trial_run(path, &mut report)?;
+    }
+    Ok(report)
+}
+
+/// Runs a mod in the sandbox, as the game does, from a scratch copy so its
+/// storage lands in a folder removed afterwards. A content mod has no code to
+/// run: `inspect` already read its content as the game does.
+fn trial_run(path: &Path, report: &mut Report) -> Result<(), String> {
+    let package = Package::read(path)?;
+    let Some(wasm) = package.wasm.as_deref() else {
+        return Ok(());
+    };
+    report.code = true;
+    report.imports = component_imports(wasm)?;
+    package
+        .manifest
+        .check_imports(report.imports.iter().map(String::as_str))?;
+    let dir = std::env::temp_dir().join(format!("horizon-mod-check-{}", std::process::id()));
+    let _ = std::fs::remove_dir_all(&dir);
+    std::fs::create_dir_all(&dir).map_err(|e| e.to_string())?;
+    let copy = dir.join("mod.hmod");
+    let result = std::fs::copy(path, &copy)
+        .map_err(|e| e.to_string())
+        .and_then(|_| play(&copy, report));
+    let _ = std::fs::remove_dir_all(&dir);
+    result
+}
+
+fn play(path: &Path, report: &mut Report) -> Result<(), String> {
+    let mut mods = Mods::load(&[path.to_path_buf()], |_| true, |_| false);
+    let failed = |mods: &Mods| match &mods.entries()[0].status {
+        Status::Failed(reason) => Some(reason.clone()),
+        _ => None,
+    };
+    if let Some(reason) = failed(&mods) {
+        return Err(format!("it didn't start: {reason}"));
+    }
+    report.commands = mods.commands().map(str::to_owned).collect();
+    for t in 0..TICKS {
+        mods.set_snapshot(Snapshot {
+            player: Some(Player {
+                x: 0.5 + t as f64 * 0.1,
+                y: 64.0,
+                z: 0.5,
+                yaw: 90.0,
+                pitch: 0.0,
+                health: 20.0,
+                food: 20,
+                dimension: "minecraft:overworld".into(),
+            }),
+            clock: Some(Clock {
+                game_time: t,
+                day_time: 1000 + t,
+            }),
+        });
+        mods.tick(t);
+        for _ in 0..FRAMES_PER_TICK {
+            mods.frame(1.0 / 60.0);
+        }
+    }
+    mods.chat("<Steve> hello");
+    for name in report.commands.clone() {
+        mods.command(&name);
+    }
+    for out in mods.drain() {
+        report.output.push(match out {
+            Output::Chat { text, .. } => format!("chat: {text}"),
+            Output::Feedback { text, error } => {
+                format!("{}: {text}", if error { "error" } else { "feedback" })
+            }
+            Output::Stopped { reason, .. } => return Err(format!("it stopped: {reason}")),
+        });
+    }
+    match failed(&mods) {
+        Some(reason) => Err(format!("it stopped: {reason}")),
+        None => Ok(()),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn fixture(name: &str) -> std::path::PathBuf {
+        Path::new(env!("CARGO_MANIFEST_DIR"))
+            .join("../horizon-mods/tests/index")
+            .join(name)
+    }
+
+    #[test]
+    fn checks_each_kind_its_own_way() {
+        let pack = fixture("cozy-1.0.0.hpack");
+        let report = check(&pack, kind_of(&pack).unwrap(), None, None).unwrap();
+        assert_eq!(report.facts.requires[0].id, "coords_hud");
+        assert!(
+            report
+                .text()
+                .contains("cozy 1.0.0 (modpack, format 1, for 26.3)")
+        );
+        // The fixture mod's code is a stand-in: its manifest reads, its run fails.
+        let hmod = fixture("coords_hud-0.1.0.hmod");
+        let key = std::fs::read_to_string(fixture("test.pub")).unwrap();
+        let sig = std::fs::read_to_string(fixture("coords_hud-0.1.0.hmod.minisig")).unwrap();
+        let key = key.lines().last().unwrap();
+        let e = check(&hmod, Kind::Mod, Some(key), Some(&sig))
+            .err()
+            .unwrap();
+        assert!(e.contains("didn't start"), "{e}");
+        let e = check(
+            &hmod,
+            Kind::Mod,
+            Some(key),
+            Some("untrusted comment: x\nRUQ=\n"),
+        )
+        .err()
+        .unwrap();
+        assert!(e.contains("signature"), "{e}");
+        let e = check(&pack, Kind::Shader, None, None).err().unwrap();
+        assert!(e.contains("shader packs open"), "{e}");
+        assert!(check(&pack, Kind::Mod, None, None).is_err());
+    }
+}

crates/cargo-horizon-mod/src/main.rs

@@ -1,13 +1,21 @@
 //! `cargo horizon-mod`: make Horizon mods in Rust (`docs/mods.md`).
 //!
-//! - `new <path> [--name "Name"] [--sdk-path <dir>]`: a mod crate from the template.
-//! - `build [--debug]`: the `.hmod` in `target/horizon-mod/`.
+//! - `new <path> [--template code|content] [--name "Name"] [--sdk-path <dir>]`:
+//!   a mod from a template: a Rust crate, or a content mod (no code).
+//! - `build [--debug]`: the `.hmod` in `target/horizon-mod/`, with the mod's
+//!   `assets/` and `data/`; a folder without `Cargo.toml` is content only.
 //! - `run [--game <horizon-client>] [-- <game args>]`: build, then play with
 //!   the mod; run `build` again and the game reloads it.
+//! - `check <file> [--json]`: what the registry checks of a submission
+//!   (`.hmod`, `.hpack`, resource pack `.zip`), with a trial run for a mod.
+//! - `registry build|review|check|list`: the registry repository's CI.
 use horizon_mods::{
-    Manifest, Package,
+    Capability, Content, Manifest, Package,
     manifest::{MANIFEST, component_imports, componentize},
 };
+mod check;
+mod registry;
+
 use std::{
     path::{Path, PathBuf},
     process::{Command, ExitCode, Stdio},
@@ -28,7 +36,9 @@ fn main() -> ExitCode {
             println!("Built {}", p.display());
         }),
         Some("run") => run(&args[1..]),
-        _ => Err("usage: cargo horizon-mod new <path> | build [--debug] | run [--game <horizon-client>] [-- <game args>]".into()),
+        Some("check") => check(&args[1..]),
+        Some("registry") => registry::main(&args[1..]),
+        _ => Err("usage: cargo horizon-mod new <path> [--template code|content] | build [--debug] | run [--game <horizon-client>] [-- <game args>] | check <file> [--kind <kind>] [--key <public key> --signature <file.minisig>] [--json] | registry build|review|check|list".into()),
     };
     match result {
         Ok(()) => ExitCode::SUCCESS,
@@ -82,19 +92,68 @@ fn new(args: &[String]) -> Result<(), String> {
             .replace("{name}", &name)
             .replace("{sdk}", &sdk)
     };
-    let files = [
+    let code = [
         ("Cargo.toml", include_str!("../template/Cargo.toml.in")),
         (MANIFEST, include_str!("../template/horizon-mod.toml")),
         ("src/lib.rs", include_str!("../template/src/lib.rs")),
         (".gitignore", include_str!("../template/gitignore")),
     ];
-    for (file, text) in files {
+    // A block copying a vanilla one, with its model, name, loot, recipe and tag.
+    let content = [
+        (
+            MANIFEST,
+            include_str!("../template/content/horizon-mod.toml"),
+        ),
+        (
+            "data/{id}/horizon/block/glowing_amethyst.json",
+            include_str!("../template/content/block.json"),
+        ),
+        (
+            "assets/{id}/blockstates/glowing_amethyst.json",
+            include_str!("../template/content/blockstate.json"),
+        ),
+        (
+            "assets/{id}/models/block/glowing_amethyst.json",
+            include_str!("../template/content/model.json"),
+        ),
+        (
+            "assets/{id}/items/glowing_amethyst.json",
+            include_str!("../template/content/item.json"),
+        ),
+        (
+            "assets/{id}/lang/en_us.json",
+            include_str!("../template/content/lang.json"),
+        ),
+        (
+            "data/{id}/loot_table/blocks/glowing_amethyst.json",
+            include_str!("../template/content/loot.json"),
+        ),
+        (
+            "data/{id}/recipe/glowing_amethyst.json",
+            include_str!("../template/content/recipe.json"),
+        ),
+        (
+            "data/minecraft/tags/block/mineable/pickaxe.json",
+            include_str!("../template/content/pickaxe.json"),
+        ),
+        (".gitignore", include_str!("../template/gitignore")),
+    ];
+    let files: &[(&str, &str)] = match flag(args, "--template").unwrap_or("code") {
+        "code" => &code,
+        "content" => &content,
+        other => return Err(format!("no template {other}: code or content")),
+    };
+    for &(file, text) in files {
+        let file = fill(file);
+        let file = file.as_str();
         let to = dir.join(file);
         std::fs::create_dir_all(to.parent().expect("a file in the mod"))
             .map_err(|e| e.to_string())?;
         std::fs::write(&to, fill(text)).map_err(|e| format!("{}: {e}", to.display()))?;
     }
-    Manifest::parse(&std::fs::read_to_string(dir.join(MANIFEST)).map_err(|e| e.to_string())?)?;
+    let manifest =
+        Manifest::parse(&std::fs::read_to_string(dir.join(MANIFEST)).map_err(|e| e.to_string())?)?;
+    Content::read(dir, &manifest)?;
     println!(
         "Created {} (mod id {id}). Next: cd {path} && cargo horizon-mod run",
         dir.display()
@@ -102,14 +161,53 @@ fn new(args: &[String]) -> Result<(), String> {
     Ok(())
 }
 
-/// Builds the crate in the current folder and packs `target/horizon-mod/<id>.hmod`.
+/// Builds the mod in the current folder and packs `target/horizon-mod/<id>.hmod`:
+/// the manifest, the crate's component (none without a `Cargo.toml`: a
+/// content mod) and the files in `assets/` and `data/`.
 fn build(release: bool) -> Result<PathBuf, String> {
-    let manifest_text = std::fs::read_to_string(MANIFEST)
+    build_in(Path::new("."), release)
+}
+
+fn build_in(root: &Path, release: bool) -> Result<PathBuf, String> {
+    let manifest_text = std::fs::read_to_string(root.join(MANIFEST))
         .map_err(|e| format!("{MANIFEST}: {e} (run this in a mod's folder)"))?;
     let manifest = Manifest::parse(&manifest_text)?;
+    let (wasm, target_dir) = if root.join("Cargo.toml").exists() {
+        let (wasm, target) = compile(root, release)?;
+        // The game refuses a component importing capabilities the manifest lacks.
+        manifest.check_imports(component_imports(&wasm)?.iter().map(String::as_str))?;
+        (Some(wasm), target)
+    } else if manifest.capabilities.contains(&Capability::Registries) {
+        (None, root.join("target"))
+    } else {
+        return Err(format!(
+            "no Cargo.toml: only a content mod (capability registries in {MANIFEST}) has no code"
+        ));
+    };
+    // The same checks as the game's, and the files in the order it lists them.
+    let content = Content::read(root, &manifest)?;
+    let mut reader = content.reader()?;
+    let mut files = Vec::with_capacity(content.files.len());
+    for name in &content.files {
+        files.push((name.as_str(), reader.read(name)?));
+    }
+    let files: Vec<(&str, &[u8])> = files.iter().map(|(n, b)| (*n, b.as_slice())).collect();
+    let dir = target_dir.join("horizon-mod");
+    std::fs::create_dir_all(&dir).map_err(|e| e.to_string())?;
+    let path = dir.join(format!("{}.hmod", manifest.id));
+    // Write then rename, so a running game never reads half a file.
+    let partial = path.with_extension("hmod.partial");
+    let bytes = Package::write_files(&manifest_text, wasm.as_deref(), &files)?;
+    std::fs::write(&partial, bytes).map_err(|e| e.to_string())?;
+    std::fs::rename(&partial, &path).map_err(|e| e.to_string())?;
+    Ok(path)
+}
+
+/// Builds the crate for WebAssembly: its component, and Cargo's target folder.
+fn compile(root: &Path, release: bool) -> Result<(Vec<u8>, PathBuf), String> {
     let cargo = std::env::var("CARGO").unwrap_or_else(|_| "cargo".into());
     let mut cmd = Command::new(cargo);
-    cmd.args([
+    cmd.current_dir(root).args([
         "build",
         "--lib",
         "--target",
@@ -137,17 +235,39 @@ fn build(release: bool) -> Result<PathBuf, String> {
         .rfind(|f| f.extension().is_some_and(|e| e == "wasm"))
         .ok_or("the build made no .wasm: is the crate a cdylib?")?;
     let wasm = componentize(&std::fs::read(&core).map_err(|e| e.to_string())?)?;
-    // The game refuses a component importing capabilities the manifest lacks.
-    manifest.check_imports(component_imports(&wasm)?.iter().map(String::as_str))?;
-    let target_dir = core.ancestors().nth(3).ok_or("unexpected target folder")?;
-    let dir = target_dir.join("horizon-mod");
-    std::fs::create_dir_all(&dir).map_err(|e| e.to_string())?;
-    let path = dir.join(format!("{}.hmod", manifest.id));
-    // Write then rename, so a running game never reads half a file.
-    let partial = path.with_extension("hmod.partial");
-    std::fs::write(&partial, Package::write(&manifest_text, &wasm)?).map_err(|e| e.to_string())?;
-    std::fs::rename(&partial, &path).map_err(|e| e.to_string())?;
-    Ok(path)
+    let target = core.ancestors().nth(3).ok_or("unexpected target folder")?;
+    Ok((wasm, target.to_path_buf()))
+}
+
+/// `check <file>`: the registry's checks of a submission, printed; fails
+/// when one does.
+fn check(args: &[String]) -> Result<(), String> {
+    let file = args
+        .first()
+        .filter(|a| !a.starts_with("--"))
+        .ok_or("cargo horizon-mod check <file>")?;
+    let path = Path::new(file);
+    let kind = match flag(args, "--kind") {
+        Some(k) => horizon_mods::index::Kind::from(k.to_string()),
+        None => check::kind_of(path)
+            .ok_or("pass --kind mod|modpack|resourcepack: the extension doesn't say")?,
+    };
+    let signature = flag(args, "--signature")
+        .map(|p| std::fs::read_to_string(p).map_err(|e| format!("{p}: {e}")))
+        .transpose()?;
+    let report = check::check(path, kind, flag(args, "--key"), signature.as_deref());
+    if args.iter().any(|a| a == "--json") {
+        let json = match &report {
+            Ok(r) => serde_json::json!({"ok": true, "report": r.json()}),
+            Err(e) => serde_json::json!({"ok": false, "error": e}),
+        };
+        println!("{json}");
+    }
+    let report = report?;
+    if !args.iter().any(|a| a == "--json") {
+        print!("{}", report.text());
+    }
+    Ok(())
 }
 
 fn run(args: &[String]) -> Result<(), String> {
@@ -198,4 +318,49 @@ mod tests {
         );
         std::fs::remove_dir_all(&dir).unwrap();
     }
+
+    #[test]
+    fn the_content_template_builds_and_checks_with_no_code() {
+        let dir = std::env::temp_dir().join(format!("horizon-mod-content-{}", std::process::id()));
+        let path = dir.join("gems");
+        let new_args = [
+            path.display().to_string(),
+            "--template".into(),
+            "content".into(),
+        ];
+        new(&new_args).unwrap();
+        assert!(!path.join("Cargo.toml").exists());
+        let hmod = build_in(&path, true).unwrap();
+        assert_eq!(hmod, path.join("target/horizon-mod/gems.hmod"));
+        let package = Package::read(&hmod).unwrap();
+        assert!(package.wasm.is_none());
+        let content = Content::read(&hmod, &package.manifest).unwrap();
+        assert!(
+            content
+                .files
+                .contains(&"data/gems/horizon/block/glowing_amethyst.json".into())
+        );
+        assert_eq!(content.files.len(), 8, "{:?}", content.files);
+        let report = check::check(&hmod, check::kind_of(&hmod).unwrap(), None, None).unwrap();
+        assert!(!report.code);
+        assert!(
+            report.text().contains("no code: content only"),
+            "{}",
+            report.text()
+        );
+        // Without registries, a mod needs code.
+        let manifest = std::fs::read_to_string(path.join(MANIFEST)).unwrap();
+        let manifest = manifest.replace("[\"registries\"]", "[]");
+        std::fs::write(path.join(MANIFEST), manifest).unwrap();
+        assert!(build_in(&path, true).unwrap_err().contains("no Cargo.toml"));
+        assert!(
+            new(&[
+                dir.join("x").display().to_string(),
+                "--template".into(),
+                "lua".into()
+            ])
+            .is_err()
+        );
+        std::fs::remove_dir_all(&dir).unwrap();
+    }
 }

crates/cargo-horizon-mod/src/registry.rs

@@ -0,0 +1,159 @@
+//! `cargo horizon-mod registry build|review|check|list`: the registry repository's CI
+//! (`ludovic111/horizon-mods`, docs/api/mod-index.md). Network-free: the
+//! workflow downloads the files and publishes what this writes.
+use horizon_mods::index::{
+    FILE_HOST,
+    registry::{self, Sources},
+};
+use std::path::Path;
+
+/// Where the registry's site is published (its icons).
+const SITE: &str = "https://ludovic111.github.io/horizon-mods/";
+
+const USAGE: &str = "usage: cargo horizon-mod registry build <checkout> --files <dir> --out <index.json> [--release <url>] [--site <url>] [--generated <time>]
+       cargo horizon-mod registry review <base checkout> <head checkout> --author <login> [--json]
+       cargo horizon-mod registry check <base checkout> <head checkout> --files <dir>
+       cargo horizon-mod registry list <checkout>";
+
+fn flag<'a>(args: &'a [String], name: &str) -> Option<&'a str> {
+    super::flag(args, name)
+}
+
+fn positional(args: &[String]) -> Vec<&str> {
+    let mut out = Vec::new();
+    let mut skip = false;
+    for a in args {
+        if skip {
+            skip = false;
+        } else if a == "--json" {
+        } else if a.starts_with("--") {
+            skip = true;
+        } else {
+            out.push(a.as_str());
+        }
+    }
+    out
+}
+
+fn lines(errors: Vec<String>) -> String {
+    format!("{} problem(s):\n  {}", errors.len(), errors.join("\n  "))
+}
+
+pub fn main(args: &[String]) -> Result<(), String> {
+    let rest = args.get(1..).unwrap_or_default();
+    let pos = positional(rest);
+    match args.first().map(String::as_str) {
+        Some("build") => {
+            let [checkout] = pos[..] else {
+                return Err(USAGE.into());
+            };
+            let (files, out) = (flag(rest, "--files"), flag(rest, "--out"));
+            let (Some(files), Some(out)) = (files, out) else {
+                return Err(USAGE.into());
+            };
+            let generated = flag(rest, "--generated")
+                .map(str::to_owned)
+                .or_else(|| std::env::var("REGISTRY_GENERATED").ok())
+                .unwrap_or_default();
+            let index = registry::build(&Sources {
+                registry: Path::new(checkout),
+                files: Path::new(files),
+                release: flag(rest, "--release").unwrap_or(FILE_HOST),
+                site: flag(rest, "--site").unwrap_or(SITE),
+                generated,
+            })
+            .map_err(lines)?;
+            let text = serde_json::to_string_pretty(&index).map_err(|e| e.to_string())?;
+            std::fs::write(out, text + "\n").map_err(|e| format!("{out}: {e}"))?;
+            println!(
+                "Wrote {out}: {} project(s), {} taken down",
+                index.projects.len(),
+                index.revoked.len()
+            );
+            Ok(())
+        }
+        Some("review") => {
+            let [base, head] = pos[..] else {
+                return Err(USAGE.into());
+            };
+            let author = flag(rest, "--author").ok_or(USAGE)?;
+            let (base, _) = registry::load(Path::new(base)).map_err(lines)?;
+            let (head, _) = registry::load(Path::new(head)).map_err(lines)?;
+            let review = registry::review(&base, &head, author);
+            if rest.iter().any(|a| a == "--json") {
+                let json = serde_json::json!({"errors": review.errors, "notes": review.notes});
+                println!("{json}");
+            } else {
+                for n in &review.notes {
+                    println!("note: {n}");
+                }
+                for e in &review.errors {
+                    println!("error: {e}");
+                }
+            }
+            if review.errors.is_empty() {
+                Ok(())
+            } else {
+                Err(format!(
+                    "{} change(s) the registry refuses",
+                    review.errors.len()
+                ))
+            }
+        }
+        // `check` (and its trial run) on each file `head` lists and `base`
+        // doesn't: a pull request's new files.
+        Some("check") => {
+            let [base, head] = pos[..] else {
+                return Err(USAGE.into());
+            };
+            let files = Path::new(flag(rest, "--files").ok_or(USAGE)?);
+            let old: Vec<String> = match registry::load(Path::new(base)) {
+                Ok((entries, _)) => entries
+                    .iter()
+                    .flat_map(|e| e.versions.iter().map(|v| v.sha256.clone()))
+                    .collect(),
+                // The first pull request has no entries to compare with.
+                Err(_) => Vec::new(),
+            };
+            let (entries, _) = registry::load(Path::new(head)).map_err(lines)?;
+            let mut failed = 0;
+            for e in &entries {
+                for v in e.versions.iter().filter(|v| !old.contains(&v.sha256)) {
+                    println!("{} {} ({}):", e.id, v.version, v.file);
+                    let report = crate::check::check(
+                        &files.join(&v.sha256),
+                        e.kind.clone(),
+                        e.key.as_deref(),
+                        v.signature.as_deref(),
+                    );
+                    match report {
+                        Ok(r) => print!("{}", r.text()),
+                        Err(err) => {
+                            failed += 1;
+                            println!("  error: {err}");
+                        }
+                    }
+                }
+            }
+            if failed == 0 {
+                Ok(())
+            } else {
+                Err(format!("{failed} file(s) failed their check"))
+            }
+        }
+        // The files CI must download for `build`: `<sha256> <id> <version> <file>`.
+        Some("list") => {
+            let [checkout] = pos[..] else {
+                return Err(USAGE.into());
+            };
+            let (entries, _) = registry::load(Path::new(checkout)).map_err(lines)?;
+            for e in &entries {
+                for v in &e.versions {
+                    println!("{} {} {} {}", v.sha256, e.id, v.version, v.file);
+                }
+            }
+            Ok(())
+        }
+        _ => Err(USAGE.into()),
+    }
+}

crates/cargo-horizon-mod/template/content/block.json

@@ -0,0 +1,4 @@
+{
+  "template": "minecraft:amethyst_block",
+  "properties": { "hardness": 2.0, "light": 7 }
+}

crates/cargo-horizon-mod/template/content/blockstate.json

@@ -0,0 +1,5 @@
+{
+  "variants": {
+    "": { "model": "{id}:block/glowing_amethyst" }
+  }
+}

crates/cargo-horizon-mod/template/content/horizon-mod.toml

@@ -0,0 +1,10 @@
+id = "{id}"
+name = "{name}"
+version = "0.1.0"
+description = ""
+authors = []
+# A content mod: blocks and items from data/ and assets/, no code (API 0.2).
+api = "0.2"
+side = "both"
+# registries: "May add blocks and items to your worlds".
+capabilities = ["registries"]

crates/cargo-horizon-mod/template/content/item.json

@@ -0,0 +1,3 @@
+{
+  "model": { "type": "minecraft:model", "model": "{id}:block/glowing_amethyst" }
+}

crates/cargo-horizon-mod/template/content/lang.json

@@ -0,0 +1,3 @@
+{
+  "block.{id}.glowing_amethyst": "Glowing Amethyst"
+}

crates/cargo-horizon-mod/template/content/loot.json

@@ -0,0 +1,11 @@
+{
+  "type": "minecraft:block",
+  "pools": [
+    {
+      "condition": { "type": "minecraft:survives_explosion" },
+      "entries": [{ "type": "minecraft:item", "name": "{id}:glowing_amethyst" }],
+      "rolls": 1
+    }
+  ],
+  "random_sequence": "{id}:blocks/glowing_amethyst"
+}

crates/cargo-horizon-mod/template/content/model.json

@@ -0,0 +1,4 @@
+{
+  "parent": "minecraft:block/cube_all",
+  "textures": { "all": "minecraft:block/amethyst_block" }
+}

crates/cargo-horizon-mod/template/content/pickaxe.json

@@ -0,0 +1,3 @@
+{
+  "values": ["{id}:glowing_amethyst"]
+}

crates/cargo-horizon-mod/template/content/recipe.json

@@ -0,0 +1,6 @@
+{
+  "type": "minecraft:crafting_shapeless",
+  "category": "building",
+  "ingredients": ["minecraft:amethyst_block", "minecraft:glowstone_dust"],
+  "result": { "id": "{id}:glowing_amethyst" }
+}

crates/horizon-assets/src/blockstate/choice.rs

@@ -4,15 +4,15 @@ use crate::json::{Result, error};
 use horizon_core::random::RandomSource;
 
 #[derive(Clone, Debug)]
-enum Choice {
-    Single(Variant),
+enum Choice<T> {
+    Single(T),
     Weighted {
-        variants: Vec<Variant>,
+        variants: Vec<T>,
         ends: Vec<i32>,
         total: i32,
     },
 }
-impl Choice {
+impl Choice<Variant> {
     fn new(value: &VariantSet) -> Result<Self> {
         match value {
             VariantSet::Single(value) => Ok(Self::Single(value.clone())),
@@ -41,7 +41,23 @@ impl Choice {
             }
         }
     }
-    fn select(&self, random: &mut impl RandomSource) -> &Variant {
+}
+impl<T> Choice<T> {
+    fn map<U>(&self, f: &mut impl FnMut(&T) -> U) -> Choice<U> {
+        match self {
+            Self::Single(value) => Choice::Single(f(value)),
+            Self::Weighted {
+                variants,
+                ends,
+                total,
+            } => Choice::Weighted {
+                variants: variants.iter().map(&mut *f).collect(),
+                ends: ends.clone(),
+                total: *total,
+            },
+        }
+    }
+    fn select(&self, random: &mut impl RandomSource) -> &T {
         match self {
             Self::Single(value) => value,
             Self::Weighted {
@@ -60,10 +76,11 @@ impl Choice {
 }
 /// Compile once per definition and share across its bound block states. Prefix
 /// sums avoid rebuilding weight totals or scanning all entries during selection.
+/// `map` swaps each variant for what it stands for (its baked model).
 #[derive(Clone, Debug)]
-pub struct CompiledChoices {
-    variants: Vec<Choice>,
-    multipart: Vec<Choice>,
+pub struct CompiledChoices<T = Variant> {
+    variants: Vec<Choice<T>>,
+    multipart: Vec<Choice<T>>,
 }
 impl CompiledChoices {
     pub fn new(definition: &BlockStateDefinition) -> Result<Self> {
@@ -82,10 +99,19 @@ impl CompiledChoices {
                 .collect::<Result<_>>()?,
         })
     }
+}
+impl<T> CompiledChoices<T> {
+    /// The same choices, with `f` of each variant in its place.
+    pub fn map<U>(&self, mut f: impl FnMut(&T) -> U) -> CompiledChoices<U> {
+        CompiledChoices {
+            variants: self.variants.iter().map(|c| c.map(&mut f)).collect(),
+            multipart: self.multipart.iter().map(|c| c.map(&mut f)).collect(),
+        }
+    }
     /// The variant `particleMaterial` comes from: the first entry of a weighted
     /// list (`WeightedVariants`) and, for a multipart root, of its first
     /// selector whether or not that selector applies (`MultiPartModel`).
-    pub fn particle_variant(&self, selected: &SelectedModels) -> Option<&Variant> {
+    pub fn particle_variant(&self, selected: &SelectedModels) -> Option<&T> {
         let choice = match selected {
             SelectedModels::Variant(index) => self.variants.get(*index)?,
             SelectedModels::Multipart(_) => self.multipart.first()?,
@@ -95,14 +121,23 @@ impl CompiledChoices {
             Choice::Weighted { variants, .. } => variants.first()?,
         })
     }
-    /// Append selected variants without allocating intermediate part lists. A
-    /// multipart root consumes nextLong even for an empty selected subset, then
-    /// resets the same random source to that seed before each selected part.
+    /// Append selected variants without allocating intermediate part lists.
     pub fn collect<'a>(
         &'a self,
         selected: &SelectedModels,
         random: &mut impl RandomSource,
-        output: &mut Vec<&'a Variant>,
+        output: &mut Vec<&'a T>,
+    ) -> Result<()> {
+        self.for_each(selected, random, |v| output.push(v))
+    }
+    /// Each selected variant, in order. A multipart root consumes nextLong
+    /// even for an empty selected subset, then resets the same random source
+    /// to that seed before each selected part.
+    pub fn for_each<'a>(
+        &'a self,
+        selected: &SelectedModels,
+        random: &mut impl RandomSource,
+        mut f: impl FnMut(&'a T),
     ) -> Result<()> {
         match selected {
             SelectedModels::Variant(index) => {
@@ -110,7 +145,7 @@ impl CompiledChoices {
                     .variants
                     .get(*index)
                     .ok_or_else(|| error("invalid variant selection"))?;
-                output.push(choice.select(random));
+                f(choice.select(random));
             }
             SelectedModels::Multipart(indices) => {
                 if indices.iter().any(|index| *index >= self.multipart.len()) {
@@ -119,7 +154,7 @@ impl CompiledChoices {
                 let seed = random.next_long();
                 for index in indices {
                     random.set_seed(seed);
-                    output.push(self.multipart[*index].select(random));
+                    f(self.multipart[*index].select(random));
                 }
             }
         }

crates/horizon-bench/src/hardware.rs

@@ -1,8 +1,7 @@
 //! 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 std::process::Command;
-
+use horizon_telemetry::system::command_output as output;
 use serde::{Deserialize, Serialize};
 
 #[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize)]
@@ -173,12 +172,6 @@ pub fn cpu_seconds(pid: u32) -> Option<f64> {
     Some(ticks / 100.0)
 }
 
-fn output(program: &str, args: &[&str]) -> Option<String> {
-    let out = Command::new(program).args(args).output().ok()?;
-    let text = String::from_utf8(out.stdout).ok()?.trim().to_owned();
-    (out.status.success() && !text.is_empty()).then_some(text)
-}
-
 #[cfg(target_os = "macos")]
 fn os_version() -> Option<String> {
     output("sw_vers", &["-productVersion"])

crates/horizon-bench/src/lib.rs

@@ -245,13 +245,19 @@ pub struct Report {
 impl Report {
     /// An empty report for this machine, created now.
     pub fn new(kind: Kind, app: App) -> Report {
+        Self::with_hardware(kind, app, Hardware::detect())
+    }
+
+    /// Starts a report using supplied hardware, without running system probes.
+    /// Interactive apps can collect the remaining machine details after their first frame.
+    pub fn with_hardware(kind: Kind, app: App, hardware: Hardware) -> Report {
         Report {
             format: FORMAT.to_owned(),
             version: VERSION,
             kind,
             created: utc_now(),
             app,
-            hardware: Hardware::detect(),
+            hardware,
             conditions: Conditions::default(),
             metrics: BTreeMap::new(),
             frames: Vec::new(),

crates/horizon-bots/src/main.rs

@@ -173,6 +173,11 @@ impl Random {
     }
 }
 
+/// One bot thread that panics poisons the locks it held; the others and the report go on.
+fn lock<T>(m: &Mutex<T>) -> std::sync::MutexGuard<'_, T> {
+    m.lock().unwrap_or_else(std::sync::PoisonError::into_inner)
+}
+
 fn raw(id: i32, write: impl FnOnce(&mut Writer)) -> Vec<u8> {
     let mut w = Writer::new();
     w.varint(id);
@@ -329,7 +334,7 @@ fn read(
 ) {
     use ids::play::clientbound as cb;
     use ids::play::serverbound as sb;
-    let send = |body: Vec<u8>| writer.lock().unwrap().send(&body);
+    let send = |body: Vec<u8>| lock(&writer).send(&body);
     let mut seen = HashSet::new();
     let mut batch = BatchSize::new();
     let mut teleports = 0u64;
@@ -338,7 +343,7 @@ fn read(
             Ok(packet) => packet,
             Err(e) => {
                 if bot.online.swap(false, Ordering::SeqCst) {
-                    *bot.error.lock().unwrap() = Some(e.to_string());
+                    *lock(&bot.error) = Some(e.to_string());
                 }
                 return;
             }
@@ -356,7 +361,7 @@ fn read(
             cb::LEVEL_CHUNK_WITH_LIGHT => {
                 bot.chunks.fetch_add(1, Ordering::Relaxed);
                 if let (Ok(x), Ok(z)) = (r.i32(), r.i32()) {
-                    if !bot.held.lock().unwrap().insert((x, z)) {
+                    if !lock(&bot.held).insert((x, z)) {
                         bot.resent.fetch_add(1, Ordering::Relaxed);
                     }
                     if seen.insert((x, z)) {
@@ -368,7 +373,7 @@ fn read(
             cb::FORGET_LEVEL_CHUNK => {
                 if let Ok(play::Clientbound::ForgetLevelChunk(p)) =
                     play::Clientbound::decode(id, &body)
-                    && bot.held.lock().unwrap().remove(&(p.pos[0], p.pos[1]))
+                    && lock(&bot.held).remove(&(p.pos[0], p.pos[1]))
                 {
                     bot.forgotten.fetch_add(1, Ordering::Relaxed);
                 }
@@ -389,7 +394,7 @@ fn read(
             }
             cb::PLAYER_POSITION => match play::Clientbound::decode(id, &body) {
                 Ok(play::Clientbound::PlayerPosition(p)) => {
-                    let mut at = bot.teleport.lock().unwrap();
+                    let mut at = lock(&bot.teleport);
                     let previous = at.unwrap_or([0.0; 3]);
                     // Relative flags: X 1, Y 2, Z 4.
                     let pos: [f64; 3] = std::array::from_fn(|i| {
@@ -420,7 +425,7 @@ fn read(
             },
             cb::DISCONNECT | cb::START_CONFIGURATION => {
                 bot.online.store(false, Ordering::SeqCst);
-                *bot.error.lock().unwrap() = Some(if id == cb::DISCONNECT {
+                *lock(&bot.error) = Some(if id == cb::DISCONNECT {
                     format!(
                         "disconnected: {}",
                         String::from_utf8_lossy(&body)
@@ -455,7 +460,7 @@ fn run_bot(
     let connection = match join(&o, &name) {
         Ok(c) => c,
         Err(e) => {
-            *bot.error.lock().unwrap() = Some(e);
+            *lock(&bot.error) = Some(e);
             return;
         }
     };
@@ -469,12 +474,12 @@ fn run_bot(
     use ids::play::serverbound as sb;
     // Wait for the spawn position.
     let spawn = loop {
-        if let Some(at) = *bot.teleport.lock().unwrap() {
+        if let Some(at) = *lock(&bot.teleport) {
             break at;
         }
         if !bot.online.load(Ordering::SeqCst) || asked.elapsed() > Duration::from_secs(60) {
-            if bot.error.lock().unwrap().is_none() {
-                *bot.error.lock().unwrap() = Some("no spawn position within 60 s".into());
+            if lock(&bot.error).is_none() {
+                *lock(&bot.error) = Some("no spawn position within 60 s".into());
             }
             return;
         }
@@ -482,7 +487,7 @@ fn run_bot(
     };
     bot.joined_after_ms
         .store(asked.elapsed().as_millis() as u64, Ordering::SeqCst);
-    let send = |body: Vec<u8>| writer.lock().unwrap().send(&body).is_ok();
+    let send = |body: Vec<u8>| lock(&writer).send(&body).is_ok();
     send(raw(sb::PLAYER_LOADED, |_| {}));
     let mut random = Random(o.seed ^ (index as u64).wrapping_mul(0x2545_F491_4F6C_DD1D));
     let mut pos = spawn;
@@ -491,17 +496,15 @@ fn run_bot(
     let mut target = pos;
     let mut next = Instant::now();
     loop {
-        if until.lock().unwrap().is_some_and(|u| Instant::now() >= u)
-            || !bot.online.load(Ordering::SeqCst)
-        {
+        if lock(&until).is_some_and(|u| Instant::now() >= u) || !bot.online.load(Ordering::SeqCst) {
             break;
         }
         // A teleport from the server wins over where the bot thought it was.
-        if let Some(at) = bot.teleport.lock().unwrap().take() {
+        if let Some(at) = lock(&bot.teleport).take() {
             pos = at;
         }
         let here = ((pos[0].floor() as i32) >> 4, (pos[2].floor() as i32) >> 4);
-        if !bot.held.lock().unwrap().contains(&here) {
+        if !lock(&bot.held).contains(&here) {
             bot.waited.fetch_add(1, Ordering::Relaxed);
         } else if pos[1] < cruise {
             pos[1] = (pos[1] + 0.5).min(cruise);
@@ -558,7 +561,7 @@ fn run_bot(
     }
     // Offline first, so the reader doesn't count the closed connection as a failure.
     bot.online.store(false, Ordering::SeqCst);
-    writer.lock().unwrap().shutdown();
+    lock(&writer).shutdown();
 }
 
 fn behaviour_of(mode: &str, index: usize) -> Behaviour {
@@ -612,13 +615,10 @@ fn main() {
         let total = |f: fn(&Bot) -> &AtomicU64| -> u64 {
             bots.iter().map(|b| f(b).load(Ordering::Relaxed)).sum()
         };
-        let failed = bots
-            .iter()
-            .filter(|b| b.error.lock().unwrap().is_some())
-            .count();
+        let failed = bots.iter().filter(|b| lock(&b.error).is_some()).count();
         if first.is_none() && online > 0 {
             first = Some(Instant::now());
-            *until.lock().unwrap() = Some(Instant::now() + Duration::from_secs(o.seconds));
+            *lock(&until) = Some(Instant::now() + Duration::from_secs(o.seconds));
         }
         println!(
             "{}",
@@ -636,10 +636,10 @@ fn main() {
             })
         );
         previous_chunks = chunks;
-        let over = until.lock().unwrap().is_some_and(|u| Instant::now() >= u);
+        let over = lock(&until).is_some_and(|u| Instant::now() >= u);
         let all_failed = failed == o.bots;
         if over || all_failed || (first.is_none() && start.elapsed() > Duration::from_secs(120)) {
-            *until.lock().unwrap() = Some(Instant::now());
+            *lock(&until) = Some(Instant::now());
             break;
         }
     }
@@ -669,7 +669,7 @@ fn main() {
             "forgotten": b.forgotten.load(Ordering::Relaxed),
             "pulled_back": b.pulled_back.load(Ordering::Relaxed),
             "waited_ticks": b.waited.load(Ordering::Relaxed),
-            "error": *b.error.lock().unwrap(),
+            "error": *lock(&b.error),
         })).collect::<Vec<_>>(),
     });
     if o.report.as_deref() == Some("-") {

crates/horizon-client/Cargo.toml

@@ -16,26 +16,26 @@ horizon-world = { path = "../horizon-world" }
 horizon-protocol = { path = "../horizon-protocol" }
 # server.properties, eula.txt and the user lists, shared with horizon-server.
 horizon-server-files = { path = "../horizon-server-files" }
+# Shader packs: reading them and turning their GLSL into naga modules.
+horizon-shaders = { path = "../horizon-shaders" }
 horizon-friends = { path = "../horizon-friends" }
 # Horizon mods: sandboxed WebAssembly components, off unless installed and turned on (docs/mods.md).
 # Their runtime is the `mods` feature.
 horizon-mods = { path = "../horizon-mods", default-features = false }
-wgpu = { version = "30.0.1", default-features = false, features = ["std", "parking_lot", "vulkan", "metal", "wgsl"] }
+wgpu = { version = "30.0.1", default-features = false, features = ["std", "parking_lot", "vulkan", "metal", "wgsl", "naga-ir"] }
 winit = "0.30.13"
 pollster = "0.4"
 bytemuck = { version = "1.24", features = ["derive"] }
 glam = "0.30"
 png = "0.18"
 sha2 = "0.10.9"
+# Server resource packs are checked and cached by their SHA-1, as vanilla does.
+sha1 = "0.10"
 serde = { version = "1", features = ["derive"] }
 serde_json = { version = "1.0.151", features = ["raw_value"] }
-# Shader packs: pack.toml, and WGSL checked before it reaches wgpu.
-toml = "1.1"
 # hlsl-out: the gfx.rs tests translate every shader as wgpu's DirectX 12 backend does. A normal feature,
 # not a dev-dependency's, so builds, tests and examples share one build of naga, wgpu and this crate.
 naga = { version = "30.0.1", features = ["wgsl-in", "hlsl-out"] }
-# Java (OptiFine/Iris) shader packs, translated to WGSL.
-horizon-shaderpack = { path = "../horizon-shaderpack" }
 # Sound (ALSA on Linux); the `audio` feature.
 cpal = { version = "0.16", optional = true }
 symphonia = { version = "0.5", default-features = false, features = ["ogg", "vorbis"] }

crates/horizon-client/assets/horizon/lang/en_us.json

@@ -0,0 +1,15 @@
+{
+  "horizon.options.controller": "Controller",
+  "horizon.options.vibration": "Vibration",
+  "horizon.options.adaptive_triggers": "Adaptive Triggers",
+  "horizon.options.lightbar": "Lightbar",
+  "horizon.options.look_sensitivity": "Look Sensitivity",
+  "horizon.options.invert_x": "Invert Look X",
+  "horizon.options.invert_y": "Invert Look Y",
+  "horizon.options.sneak_button": "Sneak Button",
+  "horizon.options.move_deadzone": "Move Deadzone",
+  "horizon.options.look_deadzone": "Look Deadzone",
+  "horizon.options.button_glyphs": "Button Glyphs",
+  "horizon.options.menu_navigation": "Menu Navigation",
+  "horizon.options.on_screen_keyboard": "On-Screen Keyboard"
+}

crates/horizon-client/assets/horizon/lang/ru_ru.json

@@ -0,0 +1,15 @@
+{
+  "horizon.options.controller": "Геймпад",
+  "horizon.options.vibration": "Вибрация",
+  "horizon.options.adaptive_triggers": "Адаптивные триггеры",
+  "horizon.options.lightbar": "Подсветка",
+  "horizon.options.look_sensitivity": "Чувствительность обзора",
+  "horizon.options.invert_x": "Инверсия обзора по X",
+  "horizon.options.invert_y": "Инверсия обзора по Y",
+  "horizon.options.sneak_button": "Кнопка приседания",
+  "horizon.options.move_deadzone": "Мёртвая зона движения",
+  "horizon.options.look_deadzone": "Мёртвая зона обзора",
+  "horizon.options.button_glyphs": "Символы кнопок",
+  "horizon.options.menu_navigation": "Навигация по меню",
+  "horizon.options.on_screen_keyboard": "Экранная клавиатура"
+}

crates/horizon-client/examples/chunk_load_bench.rs

@@ -0,0 +1,168 @@
+//! What a column costs to load, on real terrain: generates and lights the
+//! columns around a point with the vanilla generator, as a world being explored
+//! does, then meshes every section of the inner columns on this one thread, so a
+//! change to generation or meshing shows as time per column and per section.
+//!
+//!     cargo run --release -p horizon-client --example chunk_load_bench -- \
+//!         .local/horizon-client/26.3 [--seed 1234] [--center CX CZ] [--radius 8]
+//!         [--threads N] [--rounds 3]
+//!
+//! The default centre is the village of `tools/perf_bench.py`. The generation
+//! figure is wall time with N workers (the game's own pool); the mesh figure is
+//! this thread's CPU time in `Mesher::mesh`, the best of `--rounds`, so other
+//! work on the machine changes it less. The checksum of the meshes shows that an
+//! A/B pair of builds made the same ones.
+use horizon_client::{
+    assets::Assets,
+    biome::Biomes,
+    blocks::BlockFacts,
+    chunk::HEIGHT,
+    light::LightTables,
+    mesher::{MeshTables, Mesher, Region, borrow},
+    models,
+    spans::thread_cpu,
+    streaming::{Streaming, WorkerContext},
+    vanillagen::VanillaTerrain,
+    world::World,
+};
+use horizon_core::biome::{BiomeZoom, obfuscate_seed};
+use horizon_world::registry::BlockStateId;
+use std::{
+    hash::{DefaultHasher, Hash, Hasher},
+    path::PathBuf,
+    sync::Arc,
+    thread,
+    time::{Duration, Instant},
+};
+
+type Error = Box<dyn std::error::Error>;
+
+fn flag<T: std::str::FromStr>(args: &[String], name: &str, default: T) -> T {
+    args.iter()
+        .position(|a| a == name)
+        .and_then(|i| args.get(i + 1)?.parse().ok())
+        .unwrap_or(default)
+}
+
+fn main() -> Result<(), Error> {
+    let args: Vec<String> = std::env::args().collect();
+    let root = PathBuf::from(args.get(1).ok_or("usage: chunk_load_bench <resources>")?);
+    let seed: i64 = flag(&args, "--seed", 1234);
+    let radius: i32 = flag(&args, "--radius", 8);
+    let rounds: usize = flag(&args, "--rounds", 3);
+    let threads: usize = flag(
+        &args,
+        "--threads",
+        thread::available_parallelism().map_or(2, |n| n.get()),
+    );
+    let center = args
+        .iter()
+        .position(|a| a == "--center")
+        .map(|i| -> Result<(i32, i32), Error> {
+            Ok((
+                args.get(i + 1).ok_or("--center CX CZ")?.parse()?,
+                args.get(i + 2).ok_or("--center CX CZ")?.parse()?,
+            ))
+        })
+        .transpose()?
+        .unwrap_or((-60, 10));
+
+    let assets = Arc::new(Assets::load(&root)?);
+    let render = Arc::new(assets.reload(&root)?);
+    let facts = BlockFacts::load(&root, assets.registry)?;
+    let visibility = models::load_visibility(&root, assets.registry)?;
+    let biomes = Arc::new(Biomes::load(&root)?);
+    let context = Arc::new(WorkerContext {
+        tables: Arc::new(MeshTables::new(&assets, &render, &facts, visibility)?),
+        light: Arc::new(LightTables::load(&root, assets.registry, &facts)?),
+        biomes: biomes.clone(),
+        assets: assets.clone(),
+        render,
+    });
+    let terrain = VanillaTerrain::new(&root.join("worldgen"), assets.registry, &biomes, seed)?;
+
+    // Generation and light, on the game's worker pool. Meshing is left out
+    // here and measured on its own below.
+    let mut streaming = Streaming::new(Arc::new(terrain), context.clone(), threads);
+    streaming.mesh = false;
+    streaming.center = center;
+    streaming.radius = radius;
+    let mut world = World::new(BlockStateId(0), 0);
+    let started = Instant::now();
+    let mut quiet = 0;
+    while quiet < 100 {
+        let before = world.chunks.len();
+        let _ = streaming.update(&mut world);
+        thread::sleep(Duration::from_millis(2));
+        quiet = if streaming.pending() == 0 && before == world.chunks.len() {
+            quiet + 1
+        } else {
+            0
+        };
+    }
+    let generated = started.elapsed() - Duration::from_millis(2 * 100);
+    let columns = world.chunks.len();
+    println!(
+        "generated and lit {columns} columns in {:.0} ms with {threads} workers ({:.2} ms per column)",
+        generated.as_secs_f64() * 1e3,
+        generated.as_secs_f64() * 1e3 / columns.max(1) as f64
+    );
+
+    // Meshing every section of the columns whose neighbours are all loaded.
+    let inner = radius - 1;
+    let regions: Vec<(Region, i32)> = (center.0 - inner..=center.0 + inner)
+        .flat_map(|x| (center.1 - inner..=center.1 + inner).map(move |z| (x, z)))
+        .filter_map(|(x, z)| {
+            let region: Region = std::array::from_fn(|dz| {
+                std::array::from_fn(|dx| {
+                    world
+                        .chunks
+                        .get(&(x + dx as i32 - 1, z + dz as i32 - 1))
+                        .cloned()
+                })
+            });
+            region
+                .iter()
+                .flatten()
+                .all(Option::is_some)
+                .then_some(region)
+        })
+        .flat_map(|region| (0..HEIGHT / 16).map(move |sy| (region.clone(), sy)))
+        .collect();
+    let mut best = Duration::MAX;
+    let (mut vertices, mut checksum) = (0, 0);
+    for _ in 0..rounds.max(1) {
+        let mut mesher = Mesher {
+            nether_shading: false,
+            zoom: BiomeZoom::new(obfuscate_seed(seed)),
+            blend_radius: 2,
+            smooth_lighting: true,
+            cutout_leaves: true,
+            assets: &context.assets,
+            render: &context.render,
+            tables: &context.tables,
+            biomes: &context.biomes,
+            visibility: context.tables.visibility.clone(),
+        };
+        vertices = 0;
+        let mut hash = DefaultHasher::new();
+        let mut spent = Duration::ZERO;
+        for (region, sy) in &regions {
+            let started = thread_cpu().ok_or("no thread CPU clock here")?;
+            let mesh = mesher.mesh(&borrow(region), *sy);
+            spent += thread_cpu().ok_or("no thread CPU clock here")? - started;
+            vertices += mesh.solid.len() + mesh.translucent.len();
+            bytemuck::cast_slice::<_, u8>(&mesh.solid).hash(&mut hash);
+            bytemuck::cast_slice::<_, u8>(&mesh.translucent).hash(&mut hash);
+        }
+        checksum = hash.finish();
+        best = best.min(spent);
+    }
+    println!(
+        "meshed {} sections ({vertices} vertices, checksum {checksum:016x}) in {:.1} ms of CPU ({:.1} us per section)",
+        regions.len(),
+        best.as_secs_f64() * 1e3,
+        best.as_secs_f64() * 1e6 / regions.len().max(1) as f64
+    );
+    Ok(())
+}

crates/horizon-client/examples/probe/main.rs

@@ -85,6 +85,7 @@ mod sprint_probe;
 mod subtitle_fixture;
 mod tab_list_fixture;
 mod team_rules_fixture;
+mod text_display_fixture;
 mod toggle_keys_probe;
 mod tooltip_display_fixture;
 mod trading_fixture;
@@ -170,6 +171,7 @@ probes! {
     team_rules_fixture,
     toggle_keys_probe,
     tooltip_display_fixture,
+    text_display_fixture,
     trading_fixture,
     translucency_fixture,
     weather_fixture,

crates/horizon-client/examples/probe/pack_screen_fixture.rs

@@ -5,7 +5,7 @@
 //!
 //! usage: pack_screen_fixture RESOURCES CASES OUTPUT
 use horizon_client::{
-    hud::HudAtlas,
+    hud::{HudAtlas, PACK_ICON_SIZE},
     lang,
     pack_screen::{Compat, PackInfo, PackScreen, Source},
     packs::{self, Position},
@@ -13,7 +13,7 @@ use horizon_client::{
     text::Text,
 };
 use serde_json::{Value, json};
-use std::{fmt::Write as _, fs, path::PathBuf};
+use std::{fmt::Write as _, fs, path::PathBuf, sync::Arc};
 
 /// Styled runs: [text, rgb or null, bold, italic, underlined, strikethrough, obfuscated].
 pub fn runs(t: &Text) -> Value {
@@ -105,7 +105,9 @@ pub fn main() -> horizon_client::Result<()> {
                         Some("unknown") => Compat::Unknown,
                         _ => Compat::Compatible,
                     },
-                    icon: p["icon"].as_bool().unwrap_or(false),
+                    icon: p["icon"].as_bool().unwrap_or(false).then(|| {
+                        Arc::from(vec![0; (PACK_ICON_SIZE * PACK_ICON_SIZE * 4) as usize])
+                    }),
                     required: p["required"].as_bool().unwrap_or(false),
                     position: if p["position"] == "top" {
                         Position::Top

crates/horizon-client/examples/probe/recipe_book_fixture.rs

@@ -83,7 +83,7 @@ pub fn main() -> horizon_client::Result<()> {
             let mut extra = String::new();
             match kind {
                 "give" => count = book.add_recipes(&index, &list()).0,
-                "take" => count = book.remove_recipes(&index, &list()),
+                "take" => count = book.remove_recipes(&index, &list()).len(),
                 "seen" => book.remove_highlight(op["id"].as_str().unwrap_or_default()),
                 "set" => {
                     let i = match op["type"].as_str().unwrap_or_default() {

crates/horizon-client/examples/probe/section_mesh_fixture.rs

@@ -136,7 +136,6 @@ fn scene(
         blend_radius,
         smooth_lighting,
         cutout_leaves,
-        cull_leaves: false,
     };
     let section_y = int(&row["section_y"])?;
     let started = Instant::now();

crates/horizon-client/examples/probe/text_display_fixture.rs

@@ -0,0 +1,37 @@
+use horizon_client::text_display::TextDisplayData;
+use horizon_protocol::{ids, packets::play::Clientbound};
+use std::{error::Error, io::Write};
+
+pub fn main() -> Result<(), Box<dyn Error>> {
+    let args: Vec<String> = crate::args().collect();
+    let mut out = std::fs::File::create(&args[2])?;
+    for line in std::fs::read_to_string(&args[1])?.lines() {
+        let input: serde_json::Value = serde_json::from_str(line)?;
+        let hex = input["wire"].as_str().unwrap();
+        let bytes: Vec<u8> = (0..hex.len())
+            .step_by(2)
+            .map(|i| u8::from_str_radix(&hex[i..i + 2], 16))
+            .collect::<Result<_, _>>()?;
+        let Clientbound::SetEntityData(packet) =
+            Clientbound::decode(ids::play::clientbound::SET_ENTITY_DATA, &bytes)?
+        else {
+            unreachable!()
+        };
+        let mut display = TextDisplayData::default();
+        display.apply(&packet.values);
+        if let Some(angles) = input["angles"].as_array() {
+            let a: Vec<_> = angles.iter().map(|v| v.as_f64().unwrap() as f32).collect();
+            writeln!(
+                out,
+                "{}",
+                serde_json::to_string(&display.matrix([a[0], a[1]], [a[2], a[3]]).to_cols_array())?
+            )?;
+            continue;
+        }
+        let mut state = serde_json::to_value(&display)?;
+        state["text"] = display.text.plain().into();
+        state["alignment"] = format!("{:?}", display.align()).to_uppercase().into();
+        writeln!(out, "{}", state)?;
+    }
+    Ok(())
+}

crates/horizon-client/src/audio.rs

@@ -161,6 +161,9 @@ pub struct Audio {
     /// How many times each positional sound played (the control socket's `status`),
     /// with or without an audio device.
     pub heard: std::collections::BTreeMap<String, u32>,
+    /// How many times each selection was stopped ("record *", "* minecraft:…", `*` for
+    /// any), with or without an audio device, as `heard`.
+    pub stopped: std::collections::BTreeMap<String, u32>,
 }
 fn decode(path: &Path) -> Option<(Vec<f32>, u32)> {
     use symphonia::core::{
@@ -595,6 +598,7 @@ impl Audio {
             source_override: None,
             capture: None,
             heard: Default::default(),
+            stopped: Default::default(),
         }
     }
     #[cfg(not(feature = "audio"))]
@@ -825,6 +829,14 @@ impl Audio {
     /// and/or a source.
     pub fn stop_sounds(&mut self, event: Option<&str>, source: Option<usize>) {
         let event = event.map(crate::sound_events::normalize);
+        let selection = format!(
+            "{} {}",
+            source
+                .and_then(|s| crate::settings::SOUND_SOURCES.get(s))
+                .map_or("*", |s| s),
+            event.as_deref().unwrap_or("*")
+        );
+        *self.stopped.entry(selection).or_default() += 1;
         self.engine
             .stop_matching(event.as_deref(), source, &mut self.backend);
     }

crates/horizon-client/src/bin/horizon-ctl/commands.rs

@@ -147,7 +147,6 @@ const PAGES: Ty = Ty::Enum(&[
     "graphics-advanced",
     "extras",
     "horizon",
-    "shader-packs",
     "agent",
 ]);
 

crates/horizon-client/src/boss_overlay.rs

@@ -0,0 +1,243 @@
+//! `BossHealthOverlay` and `LerpingBossEvent`: the boss bars a client is
+//! showing, in the order their add packets arrived.
+use crate::{
+    hud_overlays::BossBar,
+    scoreboard::{comp_text, tag_to_json},
+    text::Text,
+};
+use horizon_protocol::packets::play::{BossAction, BossEvent};
+
+/// `LerpingBossEvent.LERP_MILLISECONDS`.
+const LERP_MS: u128 = 100;
+
+/// `Util.getMillis`.
+pub fn now_millis() -> u128 {
+    std::time::SystemTime::now()
+        .duration_since(std::time::UNIX_EPOCH)
+        .map(|d| d.as_millis())
+        .unwrap_or(0)
+}
+
+/// One `LerpingBossEvent`.
+#[derive(Clone, Debug)]
+struct Event {
+    id: u128,
+    name: Text,
+    /// The progress the lerp started from (`progress`).
+    progress: f32,
+    /// `targetPercent`.
+    target: f32,
+    /// `setTime`.
+    set_at: u128,
+    color: u8,
+    overlay: u8,
+    darken: bool,
+    music: bool,
+    fog: bool,
+}
+impl Event {
+    /// `LerpingBossEvent.getProgress`.
+    fn displayed(&self, now: u128) -> f32 {
+        let t = ((now.saturating_sub(self.set_at)) as f32 / LERP_MS as f32).clamp(0.0, 1.0);
+        self.progress + (self.target - self.progress) * t
+    }
+    /// `LerpingBossEvent.setProgress`: the bar starts the next lerp from
+    /// whatever it is showing now.
+    fn set_progress(&mut self, progress: f32, now: u128) {
+        self.progress = self.displayed(now);
+        self.target = progress;
+        self.set_at = now;
+    }
+}
+
+/// `BossHealthOverlay`: the events, plus `GameRenderer`'s world darkening.
+#[derive(Clone, Debug, Default)]
+pub struct BossOverlay {
+    events: Vec<Event>,
+    /// `bossOverlayWorldDarkening` and the previous tick's value.
+    darken: f32,
+    darken_o: f32,
+}
+impl BossOverlay {
+    pub fn reset(&mut self) {
+        *self = Self::default();
+    }
+    /// `ClientboundBossEventPacket.dispatch` into `BossHealthOverlay`'s
+    /// handler. An id already shown keeps its place when added again.
+    pub fn apply(&mut self, packet: &BossEvent, now: u128) {
+        // An ordinal past the enum shows as its last value.
+        let color = |c: i32| c.clamp(0, 6) as u8;
+        let overlay = |o: i32| o.clamp(0, 4) as u8;
+        let id = packet.id;
+        if let BossAction::Add {
+            name,
+            progress,
+            color: c,
+            overlay: o,
+            darken,
+            music,
+            fog,
+        } = &packet.action
+        {
+            let event = Event {
+                id,
+                name: comp_text(&tag_to_json(name)),
+                progress: *progress,
+                target: *progress,
+                set_at: now,
+                color: color(*c),
+                overlay: overlay(*o),
+                darken: *darken,
+                music: *music,
+                fog: *fog,
+            };
+            match self.events.iter_mut().find(|e| e.id == id) {
+                Some(slot) => *slot = event,
+                None => self.events.push(event),
+            }
+            return;
+        }
+        if let BossAction::Remove = packet.action {
+            self.events.retain(|e| e.id != id);
+            return;
+        }
+        let Some(e) = self.events.iter_mut().find(|e| e.id == id) else {
+            return;
+        };
+        match &packet.action {
+            BossAction::UpdateProgress { progress } => e.set_progress(*progress, now),
+            BossAction::UpdateName { name } => e.name = comp_text(&tag_to_json(name)),
+            BossAction::UpdateStyle {
+                color: c,
+                overlay: o,
+            } => {
+                e.color = color(*c);
+                e.overlay = overlay(*o);
+            }
+            BossAction::UpdateProperties { darken, music, fog } => {
+                (e.darken, e.music, e.fog) = (*darken, *music, *fog);
+            }
+            BossAction::Add { .. } | BossAction::Remove => {}
+        }
+    }
+    /// `GameRenderer.tick` while the level runs.
+    pub fn tick_darken(&mut self, running: bool) {
+        if !running {
+            return;
+        }
+        self.darken_o = self.darken;
+        if self.should_darken() {
+            self.darken = (self.darken + 0.05).min(1.0);
+        } else if self.darken > 0.0 {
+            self.darken = (self.darken - 0.0125).max(0.0);
+        }
+    }
+    /// `GameRenderer.bossOverlayWorldDarkening`.
+    pub fn darken_amount(&self, partial: f32) -> f32 {
+        let t = partial.clamp(0.0, 1.0);
+        self.darken_o + (self.darken - self.darken_o) * t
+    }
+    pub fn should_darken(&self) -> bool {
+        self.events.iter().any(|e| e.darken)
+    }
+    pub fn should_play_music(&self) -> bool {
+        self.events.iter().any(|e| e.music)
+    }
+    pub fn should_create_world_fog(&self) -> bool {
+        self.events.iter().any(|e| e.fog)
+    }
+    /// The bars `extractRenderState` walks, with the lerped progress.
+    pub fn bars(&self, now: u128) -> Vec<BossBar> {
+        self.events
+            .iter()
+            .map(|e| BossBar {
+                name: e.name.clone(),
+                progress: e.displayed(now),
+                color: e.color as usize,
+                overlay: e.overlay as usize,
+            })
+            .collect()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use horizon_world::nbt::Tag;
+
+    fn add(id: u128, name: &str, progress: f32, darken: bool, fog: bool) -> BossEvent {
+        BossEvent {
+            id,
+            action: BossAction::Add {
+                name: Tag::String(name.into()),
+                progress,
+                color: 5,
+                overlay: 0,
+                darken,
+                music: false,
+                fog,
+            },
+        }
+    }
+    fn progress(id: u128, progress: f32) -> BossEvent {
+        BossEvent {
+            id,
+            action: BossAction::UpdateProgress { progress },
+        }
+    }
+
+    #[test]
+    fn progress_lerps_over_a_tenth_of_a_second() {
+        let mut overlay = BossOverlay::default();
+        overlay.apply(&add(1, "W", 0.0, true, false), 0);
+        overlay.apply(&progress(1, 1.0), 0);
+        assert!((overlay.bars(50)[0].progress - 0.5).abs() < 1.0e-5);
+        assert!((overlay.bars(100)[0].progress - 1.0).abs() < 1.0e-5);
+        // A new target starts from the value on screen.
+        overlay.apply(&progress(1, 0.0), 50);
+        assert!((overlay.bars(150)[0].progress - 0.0).abs() < 1.0e-5);
+    }
+
+    #[test]
+    fn darken_ramps_and_fades() {
+        let mut overlay = BossOverlay::default();
+        overlay.apply(&add(1, "W", 1.0, true, false), 0);
+        overlay.tick_darken(true);
+        assert!((overlay.darken_amount(1.0) - 0.05).abs() < 1.0e-5);
+        overlay.apply(
+            &BossEvent {
+                id: 1,
+                action: BossAction::Remove,
+            },
+            0,
+        );
+        overlay.tick_darken(true);
+        assert!((overlay.darken - 0.0375).abs() < 1.0e-5);
+        assert!(!overlay.should_play_music());
+    }
+
+    #[test]
+    fn bars_keep_arrival_order() {
+        let mut overlay = BossOverlay::default();
+        overlay.apply(&add(2, "b", 1.0, false, true), 0);
+        overlay.apply(&add(1, "a", 1.0, false, false), 0);
+        overlay.apply(&add(2, "c", 0.5, false, true), 0);
+        // An update for a bar this client never got is ignored.
+        overlay.apply(&progress(9, 0.5), 0);
+        let names: Vec<_> = overlay
+            .bars(0)
+            .into_iter()
+            .map(|b| b.name.plain())
+            .collect();
+        assert_eq!(names, ["c", "a"]);
+        assert!(overlay.should_create_world_fog());
+        overlay.apply(
+            &BossEvent {
+                id: 2,
+                action: BossAction::Remove,
+            },
+            0,
+        );
+        assert!(!overlay.should_create_world_fog());
+    }
+}

crates/horizon-client/src/bossbar.rs

@@ -14,40 +14,64 @@ pub const STYLES: [&str; 5] = [
     "notched_12",
     "notched_20",
 ];
-/// `BossBarColor.getFormatting`.
+/// `BossBarColor.getFormatting`. Purple is dark blue in 26.3.
 pub fn color_rgb(color: &str) -> u32 {
     let name = match color {
         "pink" => "red",
         "red" => "dark_red",
-        "purple" => "dark_purple",
+        "purple" => "dark_blue",
         other => other,
     };
     text::named_color(name).unwrap_or(text::WHITE)
 }
 
+/// A version-4 shaped id from a resource id. Saved boss events do not keep
+/// their UUID (`CustomBossEvents` mints a new one on load).
+pub fn stable_uuid(id: &str) -> u128 {
+    let mut h = 0xcbf29ce484222325u64;
+    for b in id.as_bytes() {
+        h ^= u64::from(*b);
+        h = h.wrapping_mul(0x100000001b3);
+    }
+    let most = (h as i64) & -61441 | 16384;
+    let least = (h.rotate_left(17) as i64) & 4_611_686_018_427_387_903 | i64::MIN;
+    ((most as u64 as u128) << 64) | (least as u64 as u128)
+}
+
 #[derive(Clone, Debug, PartialEq)]
 pub struct BossBar {
     pub id: String,
+    /// The `ServerBossEvent` UUID. Not saved.
+    pub uuid: u128,
     pub name: Comp,
     pub color: String,
     pub style: String,
     pub value: i32,
     pub max: i32,
+    /// `ServerBossEvent.visible`. A new bar is visible; nobody sees it until
+    /// a player is added.
     pub visible: bool,
-    /// Whether the (single) local player is in the bar's player set.
-    pub player: bool,
+    pub darken: bool,
+    pub music: bool,
+    pub fog: bool,
+    /// `CustomBossEvent.players`, the UUIDs told about the bar.
+    pub players: Vec<[i32; 4]>,
 }
 impl BossBar {
     pub fn new(id: &str, name: Comp) -> Self {
         Self {
             id: id.to_owned(),
+            uuid: stable_uuid(id),
             name,
             color: "white".into(),
             style: "progress".into(),
             value: 0,
             max: 100,
             visible: true,
-            player: false,
+            darken: false,
+            music: false,
+            fog: false,
+            players: Vec::new(),
         }
     }
     /// `CustomBossEvent.getDisplayName`.
@@ -91,31 +115,34 @@ impl BossBars {
     pub fn ids(&self) -> Vec<String> {
         self.bars.iter().map(|b| b.id.clone()).collect()
     }
-    /// The saved compound; the player's UUID stands for "the local player".
-    pub fn pack(&self, player: Option<[i32; 4]>) -> Tag {
+    /// The saved compound (`CustomBossEvent.Packed`).
+    pub fn pack(&self) -> Tag {
         let mut c = Compound::new();
         for b in &self.bars {
-            let mut e = vec![
-                ("Name", json_to_tag(&b.name)),
-                ("Visible", Tag::Byte(i8::from(b.visible))),
-                ("Value", Tag::Int(b.value)),
-                ("Max", Tag::Int(b.max)),
-                ("Color", Tag::String(b.color.as_str().into())),
-                ("Overlay", Tag::String(b.style.as_str().into())),
-                ("DarkenScreen", Tag::Byte(0)),
-                ("PlayBossMusic", Tag::Byte(0)),
-                ("CreateWorldFog", Tag::Byte(0)),
-            ];
-            let players = match (b.player, player) {
-                (true, Some(u)) => vec![Tag::IntArray(u.to_vec())],
-                _ => Vec::new(),
-            };
-            e.push(("Players", Tag::List(players)));
-            c.insert(b.id.as_str().into(), Tag::compound(e));
+            let players = b
+                .players
+                .iter()
+                .map(|u| Tag::IntArray(u.to_vec()))
+                .collect();
+            c.insert(
+                b.id.as_str().into(),
+                Tag::compound([
+                    ("Name", json_to_tag(&b.name)),
+                    ("Visible", Tag::Byte(i8::from(b.visible))),
+                    ("Value", Tag::Int(b.value)),
+                    ("Max", Tag::Int(b.max)),
+                    ("Color", Tag::String(b.color.as_str().into())),
+                    ("Overlay", Tag::String(b.style.as_str().into())),
+                    ("DarkenScreen", Tag::Byte(i8::from(b.darken))),
+                    ("PlayBossMusic", Tag::Byte(i8::from(b.music))),
+                    ("CreateWorldFog", Tag::Byte(i8::from(b.fog))),
+                    ("Players", Tag::List(players)),
+                ]),
+            );
         }
         Tag::Compound(c)
     }
-    pub fn unpack(data: &Tag, player: Option<[i32; 4]>) -> Self {
+    pub fn unpack(data: &Tag) -> Self {
         let mut bars = Vec::new();
         if let Tag::Compound(c) = data {
             for (id, e) in c {
@@ -130,21 +157,30 @@ impl BossBars {
                     Some(Tag::Byte(v)) => i32::from(*v),
                     _ => d,
                 };
-                let in_players = match (get("Players"), player) {
-                    (Some(Tag::List(l)), Some(u)) => l
+                let players = match get("Players") {
+                    Some(Tag::List(l)) => l
                         .iter()
-                        .any(|t| matches!(t, Tag::IntArray(a) if a.as_slice() == u)),
-                    _ => false,
+                        .filter_map(|t| match t {
+                            Tag::IntArray(a) if a.len() == 4 => Some([a[0], a[1], a[2], a[3]]),
+                            _ => None,
+                        })
+                        .collect(),
+                    _ => Vec::new(),
                 };
+                let id = id.to_string_lossy();
                 bars.push(BossBar {
-                    id: id.to_string_lossy(),
+                    uuid: stable_uuid(&id),
+                    id,
                     name: get("Name").map_or_else(|| literal(""), tag_to_json),
                     color: text("Color", "white"),
                     style: text("Overlay", "progress"),
                     value: num("Value", 0),
                     max: num("Max", 100),
                     visible: num("Visible", 0) != 0,
-                    player: in_players,
+                    darken: num("DarkenScreen", 0) != 0,
+                    music: num("PlayBossMusic", 0) != 0,
+                    fog: num("CreateWorldFog", 0) != 0,
+                    players,
                 });
             }
         }
@@ -167,17 +203,15 @@ mod tests {
         bar.value = 25;
         bar.max = 50;
         bar.visible = true;
-        bar.player = true;
-        let uuid = Some([1, 2, 3, 4]);
-        let back = BossBars::unpack(&b.pack(uuid), uuid);
+        bar.darken = true;
+        bar.players = vec![[1, 2, 3, 4]];
+        let back = BossBars::unpack(&b.pack());
         assert_eq!(back, b);
-        // Another player's UUID does not include the local player.
-        assert!(!BossBars::unpack(&b.pack(uuid), Some([9, 9, 9, 9])).bars[0].player);
         let bar = b.get("test:x").unwrap();
         assert_eq!(bar.progress(), 0.5);
         assert_eq!(bar.display_name().plain(), "chat.square_brackets");
         assert_eq!(color_rgb("pink"), text::RED);
-        assert_eq!(color_rgb("purple"), 0xAA00AA);
+        assert_eq!(color_rgb("purple"), text::named_color("dark_blue").unwrap());
         b.remove("test:x");
         assert!(b.bars.is_empty());
     }

crates/horizon-client/src/collisions.rs

@@ -133,6 +133,30 @@ impl<W: EntityMovementWorld<Error = io::Error>> EntityMovementWorld for EntityCo
         border.collision_shape().map(Some).map_err(io::Error::other)
     }
 }
+impl EntityCollisions<'_, SceneCollisions<'_, '_>> {
+    /// `SceneCollisions::resolve` that also stops at the entity boxes.
+    pub fn resolve(
+        &mut self,
+        bounds: Aabb,
+        movement: Vec3,
+        max_step: f32,
+        on_ground: bool,
+    ) -> Result<Vec3> {
+        let context = self.blocks.context(bounds);
+        Ok(resolve_world_movement(
+            self,
+            MovementRequest {
+                entity: EntityIdentity(0),
+                context,
+                bounds,
+                movement,
+                max_step,
+                on_ground,
+                candidate_budget: 1_000_000,
+            },
+        )?)
+    }
+}
 impl SceneCollisions<'_, '_> {
     /// Position contexts permit geometric movement probes without inventing a
     /// player, inventory, effects or fluid-standing behavior; a lava walker

crates/horizon-client/src/command_storage.rs

@@ -55,7 +55,7 @@ impl CommandStorage {
                 .iter()
                 .map(|(k, v)| (k.as_str().into(), v.clone()))
                 .collect();
-            let _ = save::write_dat(
+            if let Err(e) = save::write_dat(
                 &file(root, namespace),
                 Tag::compound([
                     (
@@ -64,7 +64,9 @@ impl CommandStorage {
                     ),
                     ("DataVersion", Tag::Int(horizon_world::DATA_VERSION)),
                 ]),
-            );
+            ) {
+                log::warn!("command storage {namespace} was not written: {e}");
+            }
         }
     }
     /// `get`: an empty compound when unset.

crates/horizon-client/src/confirm_screen.rs

@@ -0,0 +1,75 @@
+//! `ConfirmScreen`: a title, a message wrapped to `width - 50` (15 lines at
+//! most) and two 150-wide buttons 4 apart and 16 below it, the whole column
+//! centred; Escape answers no.
+use crate::{
+    font::Font,
+    hud::{HudAtlas, HudBatch},
+    text::Text,
+    ui,
+};
+
+pub struct Confirm {
+    /// Each line and where it is drawn.
+    pub lines: Vec<(Text, f32, f32)>,
+    /// The yes and no buttons' corners.
+    pub buttons: [(f32, f32); 2],
+}
+impl Confirm {
+    pub fn new(font: &Font, (w, h): (f32, f32), title: &Text, message: &Text) -> Self {
+        let message: Vec<Text> = font
+            .split_lines(message, w - 50.0)
+            .into_iter()
+            .map(|(line, _)| line)
+            .take(15)
+            .collect();
+        let tw = font.width_text(title);
+        let mw = message
+            .iter()
+            .map(|l| font.width_text(l))
+            .fold(0.0, f32::max);
+        let mh = 9.0 * message.len() as f32;
+        let col = tw.max(mw).max(304.0);
+        let total = 9.0 + 8.0 + mh + 8.0 + 36.0;
+        let (lx, ly) = (((w - col) / 2.0).trunc(), ((h - total) / 2.0).trunc());
+        let cell = |cw: f32| lx + ((col - cw) / 2.0).trunc();
+        let mid = cell(mw) + (mw / 2.0).trunc();
+        let mut lines = vec![(title.clone(), cell(tw), ly)];
+        for (i, line) in message.into_iter().enumerate() {
+            let x = mid - (font.width_text(&line) / 2.0).trunc();
+            lines.push((line, x, ly + 17.0 + 9.0 * i as f32));
+        }
+        let (bx, by) = (cell(304.0), ly + 9.0 + 8.0 + mh + 8.0 + 16.0);
+        Self {
+            lines,
+            buttons: [(bx, by), (bx + 154.0, by)],
+        }
+    }
+    /// The answer a click at `cursor` gives: true for yes, false for no.
+    pub fn answer_at(&self, cursor: (f32, f32)) -> Option<bool> {
+        let [yes, no] = self.buttons;
+        let on = |(x, y): (f32, f32)| ui::hovered(cursor, x, y, 150.0, 20.0);
+        if on(yes) {
+            Some(true)
+        } else if on(no) {
+            Some(false)
+        } else {
+            None
+        }
+    }
+    /// The lines and the buttons (yes first), over whatever is behind.
+    pub fn draw(
+        &self,
+        batch: &mut HudBatch,
+        atlas: &HudAtlas,
+        cursor: (f32, f32),
+        labels: [&Text; 2],
+    ) {
+        for (line, x, y) in &self.lines {
+            batch.text_styled(atlas, line, *x, *y, u32::MAX, true);
+        }
+        for ((bx, by), label) in self.buttons.into_iter().zip(labels) {
+            let hover = ui::hovered(cursor, bx, by, 150.0, 20.0);
+            ui::button(batch, atlas, bx, by, 150.0, 20.0, label, true, hover);
+        }
+    }
+}

crates/horizon-client/src/containers.rs

@@ -382,7 +382,7 @@ impl Providers {
         );
         Self { ints, floats }
     }
-    fn eval(&self, v: &Value, fast: bool, table: &HashMap<String, Value>, depth: u32) -> f64 {
+    fn eval(v: &Value, fast: bool, table: &HashMap<String, Value>, depth: u32) -> f64 {
         if depth > 16 {
             return 0.0;
         }
@@ -390,10 +390,10 @@ impl Providers {
             Value::Number(n) => n.as_f64().unwrap_or(0.0),
             Value::String(name) => table
                 .get(name)
-                .map_or(0.0, |v| self.eval(v, fast, table, depth + 1)),
+                .map_or(0.0, |v| Self::eval(v, fast, table, depth + 1)),
             Value::Object(o) => {
                 let f =
-                    |k: &str| self.eval(o.get(k).unwrap_or(&Value::Null), fast, table, depth + 1);
+                    |k: &str| Self::eval(o.get(k).unwrap_or(&Value::Null), fast, table, depth + 1);
                 match o.get("type").and_then(Value::as_str).unwrap_or("") {
                     "minecraft:div" => {
                         let r = f("right");
@@ -425,14 +425,14 @@ impl Providers {
     }
     /// A plain `context_int_provider` value or reference (no context conditions).
     pub fn int_value(&self, v: &Value) -> i32 {
-        self.eval(v, false, &self.ints, 0) as i32
+        Self::eval(v, false, &self.ints, 0) as i32
     }
     /// A plain `context_float_provider` value or reference; `default` when absent.
     pub fn float_value(&self, v: &Value, default: f32) -> f32 {
         if v.is_null() {
             default
         } else {
-            self.eval(v, false, &self.floats, 0) as f32
+            Self::eval(v, false, &self.floats, 0) as f32
         }
     }
     #[cfg(test)]
@@ -446,14 +446,14 @@ impl Providers {
         items
             .get(&stack.item)
             .and_then(|i| i.fuel.as_ref())
-            .map_or(0, |(time, _)| self.eval(time, fast, &self.ints, 0) as i32)
+            .map_or(0, |(time, _)| Self::eval(time, fast, &self.ints, 0) as i32)
     }
     pub fn speed(&self, items: &Items, stack: &ItemStack, fast: bool) -> f32 {
         items
             .get(&stack.item)
             .and_then(|i| i.fuel.as_ref())
             .map_or(1.0, |(_, speed)| {
-                self.eval(speed, fast, &self.floats, 0) as f32
+                Self::eval(speed, fast, &self.floats, 0) as f32
             })
     }
 }

crates/horizon-client/src/discord_presence.rs

@@ -0,0 +1,623 @@
+//! Discord Rich Presence: "Playing Horizon" on the player's Discord profile, with what they are
+//! doing (docs/native-client.md). A thread of its own talks to the Discord app on this computer
+//! through its local IPC socket (Discord's RPC docs: `discord-ipc-N`, frames of opcode u32 LE +
+//! length u32 LE + JSON). The game only calls [`set`] each frame: a change wakes the thread,
+//! which connects when Discord runs, retries every 15 s when it doesn't, keeps under Discord's
+//! update limit and clears the activity on quit. Nothing is sent with the setting off,
+//! or with `HORIZON_NO_DISCORD=1`.
+use std::collections::VecDeque;
+use std::io::{self, Read, Write};
+use std::path::PathBuf;
+use std::sync::{Condvar, Mutex, OnceLock};
+use std::thread::Thread;
+use std::time::{Duration, Instant, SystemTime, UNIX_EPOCH};
+
+use serde_json::{Value, json};
+
+use crate::command::args::GameMode;
+
+/// The "Horizon" application on Discord's developer portal (public: it names the game). Its
+/// Rich Presence assets: `horizon`, the logo.
+pub const DISCORD_APP_ID: &str = "1563857609738690560";
+/// Whether the application has the game-mode images (`survival`, `creative`, `adventure`,
+/// `spectator`) beside the logo; it doesn't yet.
+const MODE_IMAGES: bool = false;
+/// Points the game at a test's fake Discord (a folder holding `discord-ipc-0`).
+const IPC_DIR_ENV: &str = "HORIZON_DISCORD_IPC_DIR";
+
+/// Discord drops activity updates beyond 5 in 20 seconds.
+const BURST: usize = 5;
+const WINDOW: Duration = Duration::from_secs(20);
+/// Between two tries to reach Discord while it isn't running.
+const RETRY: Duration = Duration::from_secs(15);
+/// The activity is sent again this often, so a Discord restarted meanwhile gets it back.
+const REFRESH: Duration = Duration::from_secs(60);
+
+const HANDSHAKE: u32 = 0;
+const FRAME: u32 = 1;
+const CLOSE: u32 = 2;
+const PING: u32 = 3;
+const PONG: u32 = 4;
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum Dimension {
+    Overworld,
+    Nether,
+    End,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum Play {
+    Singleplayer,
+    /// A server or someone else's LAN world. Its address and name are never shown.
+    Multiplayer,
+    /// This world is open to LAN or friends; `players` counts the host.
+    Hosting {
+        players: usize,
+    },
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum Status {
+    /// The player turned Rich Presence off: the activity is cleared.
+    Off,
+    Menus,
+    World {
+        play: Play,
+        dimension: Dimension,
+        mode: GameMode,
+    },
+}
+
+/// What the game wants shown, and since when it has been in a world.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+struct Wanted {
+    status: Status,
+    /// Unix seconds: when the player entered the world (dimension changes keep it).
+    since: Option<u64>,
+}
+impl Wanted {
+    /// A new status at `now`; false if it is the one already wanted.
+    fn update(&mut self, status: Status, now: u64) -> bool {
+        if self.status == status {
+            return false;
+        }
+        let in_world = |s: Status| matches!(s, Status::World { .. });
+        if !in_world(status) {
+            self.since = None;
+        } else if !in_world(self.status) {
+            self.since = Some(now);
+        }
+        self.status = status;
+        true
+    }
+}
+
+struct Shared {
+    wanted: Wanted,
+    stop: bool,
+    stopped: bool,
+}
+static SHARED: Mutex<Shared> = Mutex::new(Shared {
+    wanted: Wanted {
+        status: Status::Menus,
+        since: None,
+    },
+    stop: false,
+    stopped: false,
+});
+static STOPPED: Condvar = Condvar::new();
+static THREAD: OnceLock<Thread> = OnceLock::new();
+
+/// Starts the presence thread, once: when the game starts, never for a dedicated server.
+/// `automated` runs (offscreen, benchmarks) only talk to a test's fake Discord.
+pub fn start(enabled: bool, automated: bool) {
+    let fake_discord = std::env::var_os(IPC_DIR_ENV).is_some();
+    if THREAD.get().is_some()
+        || std::env::var_os("HORIZON_NO_DISCORD").is_some_and(|v| v != "0")
+        || (automated && !fake_discord)
+    {
+        return;
+    }
+    if !enabled {
+        lock().wanted.status = Status::Off;
+    }
+    match std::thread::Builder::new()
+        .name("Discord presence".into())
+        .spawn(run)
+    {
+        Ok(handle) => {
+            let _ = THREAD.set(handle.thread().clone());
+        }
+        Err(e) => log::warn!("Horizon: no Discord presence: {e}"),
+    }
+}
+
+/// What the player does now; only a change wakes the thread. Free without [`start`].
+pub fn set(status: Status) {
+    let Some(thread) = THREAD.get() else {
+        return;
+    };
+    if lock().wanted.update(status, unix_now()) {
+        thread.unpark();
+    }
+}
+
+/// On quit: clears the activity, waiting at most a moment for Discord.
+pub fn stop() {
+    let Some(thread) = THREAD.get() else {
+        return;
+    };
+    let mut shared = lock();
+    shared.stop = true;
+    thread.unpark();
+    let _ = STOPPED.wait_timeout_while(shared, Duration::from_millis(300), |s| !s.stopped);
+}
+
+fn lock() -> std::sync::MutexGuard<'static, Shared> {
+    SHARED.lock().unwrap_or_else(|e| e.into_inner())
+}
+
+fn unix_now() -> u64 {
+    SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .map_or(0, |d| d.as_secs())
+}
+
+fn run() {
+    let mut client: Option<Client> = None;
+    let mut sent: Option<(Wanted, Instant)> = None;
+    let mut last_try: Option<Instant> = None;
+    let mut limit = RateLimit::default();
+    loop {
+        let (wanted, stop) = {
+            let s = lock();
+            (s.wanted, s.stop)
+        };
+        if stop || wanted.status == Status::Off {
+            if let Some(mut c) = client.take() {
+                let _ = c.set_activity(None);
+                c.close();
+            }
+            sent = None;
+            if stop {
+                lock().stopped = true;
+                STOPPED.notify_all();
+                return;
+            }
+            std::thread::park();
+            continue;
+        }
+        let now = Instant::now();
+        if client.is_none() {
+            if let Some(wait) = last_try.and_then(|t| RETRY.checked_sub(now - t)) {
+                std::thread::park_timeout(wait);
+                continue;
+            }
+            last_try = Some(now);
+            client = Client::connect();
+            if client.is_none() {
+                continue;
+            }
+        }
+        let due = sent.is_none_or(|(w, at)| w != wanted || now - at >= REFRESH);
+        if !due {
+            let (_, at) = sent.expect("sent");
+            std::thread::park_timeout(REFRESH - (now - at));
+            continue;
+        }
+        let wait = limit.wait(now);
+        if !wait.is_zero() {
+            std::thread::park_timeout(wait);
+            continue;
+        }
+        limit.record(now);
+        let c = client.as_mut().expect("connected");
+        match c.set_activity(activity(wanted.status, wanted.since)) {
+            Ok(()) => sent = Some((wanted, now)),
+            Err(e) => {
+                log::info!("Horizon: Discord presence disconnected ({e})");
+                client = None;
+                sent = None;
+            }
+        }
+    }
+}
+
+/// The activity Discord shows for `status`; `None` clears it.
+fn activity(status: Status, since: Option<u64>) -> Option<Value> {
+    let mut assets = json!({"large_image": "horizon", "large_text": "Horizon"});
+    let (details, state, party) = match status {
+        Status::Off => return None,
+        Status::Menus => ("In the menus", None, None),
+        Status::World {
+            play,
+            dimension,
+            mode,
+        } => {
+            if MODE_IMAGES {
+                let (key, text) = match mode {
+                    GameMode::Survival => ("survival", "Survival"),
+                    GameMode::Creative => ("creative", "Creative"),
+                    GameMode::Adventure => ("adventure", "Adventure"),
+                    GameMode::Spectator => ("spectator", "Spectator"),
+                };
+                assets["small_image"] = key.into();
+                assets["small_text"] = text.into();
+            }
+            let place = match dimension {
+                Dimension::Overworld => "In the Overworld",
+                Dimension::Nether => "In the Nether",
+                Dimension::End => "In the End",
+            };
+            let (details, party) = match play {
+                Play::Singleplayer => ("Singleplayer", None),
+                Play::Multiplayer => ("Multiplayer", None),
+                Play::Hosting { players } => ("Hosting a world", Some(players)),
+            };
+            (details, Some(place), party)
+        }
+    };
+    let mut a = json!({"details": details, "assets": assets});
+    if let Some(state) = state {
+        a["state"] = state.into();
+    }
+    if let Some(start) = since {
+        a["timestamps"] = json!({"start": start});
+    }
+    if let Some(players) = party {
+        let max = crate::lan::MAX_PLAYERS;
+        a["party"] = json!({
+            "id": format!("horizon-{}", std::process::id()),
+            "size": [players.clamp(1, max), max],
+        });
+    }
+    Some(a)
+}
+
+/// At most [`BURST`] updates in any [`WINDOW`].
+#[derive(Default)]
+struct RateLimit {
+    sent: VecDeque<Instant>,
+}
+impl RateLimit {
+    /// How long until the next update may go.
+    fn wait(&self, now: Instant) -> Duration {
+        if self.sent.len() < BURST {
+            return Duration::ZERO;
+        }
+        (self.sent[0] + WINDOW).saturating_duration_since(now)
+    }
+    fn record(&mut self, now: Instant) {
+        if self.sent.len() == BURST {
+            self.sent.pop_front();
+        }
+        self.sent.push_back(now);
+    }
+}
+
+fn encode(op: u32, payload: &Value) -> Vec<u8> {
+    let body = payload.to_string();
+    let mut frame = Vec::with_capacity(8 + body.len());
+    frame.extend_from_slice(&op.to_le_bytes());
+    frame.extend_from_slice(&(body.len() as u32).to_le_bytes());
+    frame.extend_from_slice(body.as_bytes());
+    frame
+}
+
+fn read_frame(r: &mut impl Read) -> io::Result<(u32, Value)> {
+    let mut header = [0; 8];
+    r.read_exact(&mut header)?;
+    let op = u32::from_le_bytes(header[..4].try_into().expect("4 bytes"));
+    let len = u32::from_le_bytes(header[4..].try_into().expect("4 bytes")) as usize;
+    if len > 1 << 20 {
+        return Err(io::Error::new(
+            io::ErrorKind::InvalidData,
+            "frame too large",
+        ));
+    }
+    let mut body = vec![0; len];
+    r.read_exact(&mut body)?;
+    Ok((op, serde_json::from_slice(&body)?))
+}
+
+trait Pipe: Read + Write + Send {}
+impl<T: Read + Write + Send> Pipe for T {}
+
+struct Client {
+    pipe: Box<dyn Pipe>,
+    nonce: u64,
+}
+impl Client {
+    /// The first Discord socket that answers the handshake with READY.
+    fn connect() -> Option<Self> {
+        sockets().into_iter().find_map(|path| {
+            let mut client = Client {
+                pipe: open(&path).ok()?,
+                nonce: 0,
+            };
+            match client.handshake() {
+                Ok(()) => {
+                    log::info!("Horizon: connected to Discord for Rich Presence");
+                    Some(client)
+                }
+                Err(e) => {
+                    log::debug!("Horizon: Discord at {} refused: {e}", path.display());
+                    None
+                }
+            }
+        })
+    }
+    fn handshake(&mut self) -> io::Result<()> {
+        let hello = json!({"v": 1, "client_id": DISCORD_APP_ID});
+        self.pipe.write_all(&encode(HANDSHAKE, &hello))?;
+        self.reply(|frame| frame["evt"] == "READY")
+    }
+    fn set_activity(&mut self, activity: Option<Value>) -> io::Result<()> {
+        self.nonce += 1;
+        let nonce = self.nonce.to_string();
+        let command = json!({
+            "cmd": "SET_ACTIVITY",
+            "args": {"pid": std::process::id(), "activity": activity},
+            "nonce": nonce,
+        });
+        self.pipe.write_all(&encode(FRAME, &command))?;
+        self.reply(|frame| frame["nonce"] == nonce.as_str())
+    }
+    /// Reads until the frame `ours` picks, answering pings; an ERROR is logged, not fatal.
+    fn reply(&mut self, ours: impl Fn(&Value) -> bool) -> io::Result<()> {
+        loop {
+            match read_frame(&mut self.pipe)? {
+                (FRAME, frame) if ours(&frame) => {
+                    if frame["evt"] == "ERROR" {
+                        log::info!("Horizon: Discord presence: {}", frame["data"]["message"]);
+                    }
+                    return Ok(());
+                }
+                (PING, frame) => self.pipe.write_all(&encode(PONG, &frame))?,
+                (CLOSE, frame) => {
+                    return Err(io::Error::new(
+                        io::ErrorKind::ConnectionAborted,
+                        frame["message"].as_str().unwrap_or("closed").to_owned(),
+                    ));
+                }
+                _ => {}
+            }
+        }
+    }
+    fn close(mut self) {
+        let _ = self.pipe.write_all(&encode(CLOSE, &json!({})));
+    }
+}
+
+/// Where Discord listens: `discord-ipc-0..9` in the temporary folders (and Flatpak's and
+/// Snap's subfolders) on Linux and macOS, named pipes on Windows.
+fn sockets() -> Vec<PathBuf> {
+    sockets_with(|key| std::env::var_os(key), cfg!(windows))
+}
+
+fn sockets_with(var: impl Fn(&str) -> Option<std::ffi::OsString>, windows: bool) -> Vec<PathBuf> {
+    let names = (0..10).map(|n| format!("discord-ipc-{n}"));
+    if let Some(dir) = var(IPC_DIR_ENV) {
+        return names.map(|n| PathBuf::from(&dir).join(n)).collect();
+    }
+    if windows {
+        return names.map(|n| PathBuf::from(r"\\?\pipe\").join(n)).collect();
+    }
+    let mut dirs: Vec<PathBuf> = ["XDG_RUNTIME_DIR", "TMPDIR", "TMP", "TEMP"]
+        .into_iter()
+        .filter_map(&var)
+        .map(PathBuf::from)
+        .collect();
+    dirs.push("/tmp".into());
+    dirs.dedup();
+    let mut paths = Vec::new();
+    for dir in dirs {
+        for sub in ["", "app/com.discordapp.Discord", "snap.discord"] {
+            paths.extend(names.clone().map(|n| dir.join(sub).join(n)));
+        }
+    }
+    paths
+}
+
+#[cfg(unix)]
+fn open(path: &std::path::Path) -> io::Result<Box<dyn Pipe>> {
+    let stream = std::os::unix::net::UnixStream::connect(path)?;
+    // A Discord that stops answering costs this thread a few seconds, never the game.
+    stream.set_read_timeout(Some(Duration::from_secs(5)))?;
+    Ok(Box::new(stream))
+}
+
+#[cfg(windows)]
+fn open(path: &std::path::Path) -> io::Result<Box<dyn Pipe>> {
+    let pipe = std::fs::OpenOptions::new()
+        .read(true)
+        .write(true)
+        .open(path)?;
+    Ok(Box::new(pipe))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn world(play: Play, dimension: Dimension) -> Status {
+        Status::World {
+            play,
+            dimension,
+            mode: GameMode::Survival,
+        }
+    }
+
+    /// The folders a real Discord listens in: `$TMPDIR` on macOS, `$XDG_RUNTIME_DIR` on Linux (and its
+    /// Flatpak and Snap subfolders), named pipes on Windows.
+    #[test]
+    fn sockets_cover_where_discord_listens() {
+        let env = |pairs: &'static [(&'static str, &'static str)]| {
+            move |key: &str| {
+                pairs
+                    .iter()
+                    .find(|(k, _)| *k == key)
+                    .map(|(_, v)| std::ffi::OsString::from(v))
+            }
+        };
+        let macos = sockets_with(env(&[("TMPDIR", "/var/folders/xy/abc/T/")]), false);
+        assert_eq!(
+            macos[0],
+            PathBuf::from("/var/folders/xy/abc/T/discord-ipc-0")
+        );
+        assert!(macos.contains(&PathBuf::from("/var/folders/xy/abc/T/discord-ipc-9")));
+        assert!(macos.contains(&PathBuf::from("/tmp/discord-ipc-0")));
+
+        let linux = sockets_with(
+            env(&[("XDG_RUNTIME_DIR", "/run/user/1000"), ("TMPDIR", "/tmp")]),
+            false,
+        );
+        assert_eq!(linux[0], PathBuf::from("/run/user/1000/discord-ipc-0"));
+        for path in [
+            "/run/user/1000/app/com.discordapp.Discord/discord-ipc-0",
+            "/run/user/1000/snap.discord/discord-ipc-0",
+            "/tmp/discord-ipc-0",
+        ] {
+            assert!(linux.contains(&PathBuf::from(path)), "{path}");
+        }
+        assert_eq!(linux.len(), 2 * 3 * 10, "/tmp is listed once");
+
+        let bare = sockets_with(env(&[]), false);
+        assert_eq!(bare[0], PathBuf::from("/tmp/discord-ipc-0"));
+
+        let windows = sockets_with(env(&[("TEMP", r"C:\Temp")]), true);
+        assert_eq!(windows.len(), 10);
+        // `Path::join` only uses `\` as the separator on Windows itself.
+        #[cfg(windows)]
+        assert_eq!(windows[0], PathBuf::from(r"\\?\pipe\discord-ipc-0"));
+
+        let fake = sockets_with(
+            env(&[("HORIZON_DISCORD_IPC_DIR", "/tmp/hz"), ("TMPDIR", "/x")]),
+            false,
+        );
+        assert_eq!(fake.len(), 10);
+        assert_eq!(fake[0], PathBuf::from("/tmp/hz/discord-ipc-0"));
+    }
+
+    #[test]
+    fn frames_round_trip() {
+        let frame = encode(FRAME, &json!({"cmd": "SET_ACTIVITY"}));
+        assert_eq!(&frame[..4], &[1, 0, 0, 0]);
+        assert_eq!(frame[4..8], (frame.len() as u32 - 8).to_le_bytes());
+        let (op, value) = read_frame(&mut frame.as_slice()).unwrap();
+        assert_eq!((op, value), (FRAME, json!({"cmd": "SET_ACTIVITY"})));
+        assert!(read_frame(&mut &frame[..6]).is_err());
+        let huge = [1, 0, 0, 0, 0, 0, 0, 2];
+        assert!(read_frame(&mut huge.as_slice()).is_err());
+    }
+
+    #[test]
+    fn activities_say_what_the_player_does_and_nothing_private() {
+        assert_eq!(activity(Status::Off, None), None);
+        let menus = activity(Status::Menus, None).unwrap();
+        assert_eq!(menus["details"], "In the menus");
+        assert!(menus.get("state").is_none() && menus.get("timestamps").is_none());
+        assert_eq!(menus["assets"]["large_image"], "horizon");
+
+        let single = activity(world(Play::Singleplayer, Dimension::Nether), Some(1000)).unwrap();
+        assert_eq!(single["details"], "Singleplayer");
+        assert_eq!(single["state"], "In the Nether");
+        assert_eq!(single["timestamps"]["start"], 1000);
+        assert!(single.get("party").is_none());
+        assert!(single["assets"].get("small_image").is_none());
+
+        let multi = activity(world(Play::Multiplayer, Dimension::End), Some(5)).unwrap();
+        assert_eq!(multi["details"], "Multiplayer");
+        assert_eq!(multi["state"], "In the End");
+
+        let host = world(Play::Hosting { players: 3 }, Dimension::Overworld);
+        let host = activity(host, Some(5)).unwrap();
+        assert_eq!(host["details"], "Hosting a world");
+        assert_eq!(host["state"], "In the Overworld");
+        assert_eq!(host["party"]["size"], json!([3, 8]));
+    }
+
+    #[test]
+    fn time_counts_from_entering_the_world() {
+        let mut w = Wanted {
+            status: Status::Menus,
+            since: None,
+        };
+        assert!(!w.update(Status::Menus, 10));
+        assert!(w.update(world(Play::Singleplayer, Dimension::Overworld), 20));
+        assert_eq!(w.since, Some(20));
+        // Another dimension, opening to LAN: the same visit.
+        assert!(w.update(world(Play::Singleplayer, Dimension::Nether), 30));
+        assert!(w.update(world(Play::Hosting { players: 1 }, Dimension::Nether), 40));
+        assert_eq!(w.since, Some(20));
+        assert!(w.update(Status::Menus, 50));
+        assert_eq!(w.since, None);
+        assert!(w.update(world(Play::Multiplayer, Dimension::Overworld), 60));
+        assert_eq!(w.since, Some(60));
+        assert!(w.update(Status::Off, 70));
+        assert_eq!(w.since, None);
+    }
+
+    #[test]
+    fn at_most_five_updates_in_twenty_seconds() {
+        let t = Instant::now();
+        let mut limit = RateLimit::default();
+        for i in 0..5 {
+            let now = t + Duration::from_secs(i);
+            assert_eq!(limit.wait(now), Duration::ZERO);
+            limit.record(now);
+        }
+        assert_eq!(
+            limit.wait(t + Duration::from_secs(5)),
+            Duration::from_secs(15)
+        );
+        assert_eq!(limit.wait(t + WINDOW), Duration::ZERO);
+        limit.record(t + WINDOW);
+        assert_eq!(limit.wait(t + WINDOW), Duration::from_secs(1));
+    }
+
+    /// A fake Discord: answers the handshake with READY, each command with its nonce, after a ping.
+    #[cfg(unix)]
+    #[test]
+    fn talks_to_discord_over_its_socket() {
+        let dir = std::env::temp_dir().join(format!("horizon-discord-{}", std::process::id()));
+        std::fs::create_dir_all(&dir).unwrap();
+        let path = dir.join("discord-ipc-0");
+        let _ = std::fs::remove_file(&path);
+        let listener = std::os::unix::net::UnixListener::bind(&path).unwrap();
+        let server = std::thread::spawn(move || {
+            let (mut s, _) = listener.accept().unwrap();
+            let (op, hello) = read_frame(&mut s).unwrap();
+            assert_eq!((op, &hello["v"]), (HANDSHAKE, &json!(1)));
+            let ready = json!({"cmd": "DISPATCH", "evt": "READY", "data": {"v": 1}});
+            s.write_all(&encode(FRAME, &ready)).unwrap();
+            let mut got = Vec::new();
+            for _ in 0..2 {
+                let (op, cmd) = read_frame(&mut s).unwrap();
+                assert_eq!(op, FRAME);
+                s.write_all(&encode(PING, &json!({"n": 1}))).unwrap();
+                assert_eq!(read_frame(&mut s).unwrap(), (PONG, json!({"n": 1})));
+                let reply = json!({"cmd": "SET_ACTIVITY", "nonce": cmd["nonce"], "data": null});
+                s.write_all(&encode(FRAME, &reply)).unwrap();
+                got.push(cmd);
+            }
+            got
+        });
+        let mut client = Client {
+            pipe: open(&path).unwrap(),
+            nonce: 0,
+        };
+        client.handshake().unwrap();
+        let shown = activity(world(Play::Singleplayer, Dimension::End), Some(7));
+        client.set_activity(shown.clone()).unwrap();
+        client.set_activity(None).unwrap();
+        let got = server.join().unwrap();
+        assert_eq!(got[0]["cmd"], "SET_ACTIVITY");
+        assert_eq!(got[0]["args"]["pid"], std::process::id());
+        assert_eq!(got[0]["args"]["activity"], shown.unwrap());
+        assert_eq!(got[1]["args"]["activity"], Value::Null);
+        assert_ne!(got[0]["nonce"], got[1]["nonce"]);
+        let _ = std::fs::remove_dir_all(dir);
+    }
+}

crates/horizon-client/src/entity_nbt.rs

@@ -1155,6 +1155,72 @@ pub fn arrow_from_nbt(
     Some((p, tag.get("inBlockState").cloned()))
 }
 
+/// `LargeFireball` and `SmallFireball`: `AbstractHurtingProjectile`'s
+/// `acceleration_power`, `Projectile`'s owner and flags, `ExplosionPower`.
+pub fn fireball_to_nbt(
+    p: &Projectile,
+    uuid: [i32; 4],
+    owner: Option<[i32; 4]>,
+    raw: Option<&Tag>,
+) -> Option<Tag> {
+    let power = match p.kind {
+        ProjectileKind::LargeFireball { power } => Some(power),
+        ProjectileKind::SmallFireball => None,
+        _ => return None,
+    };
+    let base = Base {
+        id: p.kind.id(),
+        uuid,
+        position: p.position,
+        motion: p.velocity,
+        rotation: [p.yaw, p.pitch],
+        on_ground: false,
+        fall_distance: 0.0,
+    };
+    let mut tag = base.tag(raw);
+    put(
+        &mut tag,
+        "acceleration_power",
+        Tag::Double(p.acceleration.to_bits()),
+    );
+    // Projectile: LeftOwner only when set; HasBeenShot once it has ticked
+    // (a fireball saved before its first tick keeps what it was loaded with).
+    if let Tag::Compound(map) = &mut tag {
+        map.remove(&"LeftOwner".into());
+    }
+    if p.left_owner {
+        put(&mut tag, "LeftOwner", Tag::Byte(1));
+    }
+    if p.age > 0 || tag.get("HasBeenShot").is_none() {
+        put(&mut tag, "HasBeenShot", Tag::Byte(i8::from(p.age > 0)));
+    }
+    if let Some(power) = power {
+        put(&mut tag, "ExplosionPower", Tag::Byte(power as i8));
+    }
+    if let Some(owner) = owner {
+        put(&mut tag, "Owner", Tag::IntArray(owner.to_vec()));
+    }
+    Some(tag)
+}
+
+pub fn fireball_from_nbt(tag: &Tag, player: Option<[i32; 4]>) -> Option<Projectile> {
+    let kind = match kind(tag)?.as_str() {
+        "minecraft:fireball" => ProjectileKind::LargeFireball {
+            power: number(tag.get("ExplosionPower")).unwrap_or(1) as i32,
+        },
+        "minecraft:small_fireball" => ProjectileKind::SmallFireball,
+        _ => return None,
+    };
+    let owner = uuid_from_tag(tag.get("Owner"));
+    let from_player = player.is_some() && owner == player;
+    let mut p = Projectile::new(kind, position(tag)?, from_player.then_some(Who::Player));
+    p.velocity = motion(tag);
+    [p.yaw, p.pitch] = rotation(tag);
+    p.left_owner = flag(tag, "LeftOwner");
+    p.acceleration = float(tag.get("acceleration_power")).unwrap_or(0.1);
+    Some(p)
+}
+
 /// `FallingBlockEntity`: BlockState, Time, DropItem, HurtEntities.
 #[allow(clippy::too_many_arguments)]
 pub fn falling_block_to_nbt(
@@ -2139,3 +2205,41 @@ mod sheep_nbt_tests {
         assert_eq!((back.extra.color, back.extra.sheared), (14, true));
     }
 }
+
+#[cfg(test)]
+mod fireball_nbt_tests {
+    use super::*;
+    #[test]
+    fn a_fireball_round_trips_its_flight() {
+        let raw = Tag::compound([
+            ("id", Tag::String("minecraft:fireball".into())),
+            ("Pos", doubles(&[1.0, 70.0, -2.5])),
+            ("Motion", doubles(&[0.0, -0.5, 1.0])),
+            ("ExplosionPower", Tag::Byte(4)),
+            ("acceleration_power", Tag::Double(0.0f64.to_bits())),
+        ]);
+        let p = fireball_from_nbt(&raw, None).unwrap();
+        assert_eq!(p.kind, ProjectileKind::LargeFireball { power: 4 });
+        assert_eq!((p.velocity.z, p.acceleration), (1.0, 0.0));
+        let back = fireball_to_nbt(&p, [1, 2, 3, 4], None, None).unwrap();
+        assert_eq!(number(back.get("ExplosionPower")), Some(4));
+        assert_eq!(float(back.get("acceleration_power")), Some(0.0));
+        // Projectile.addAdditionalSaveData: no LeftOwner unless set, HasBeenShot always.
+        assert!(back.get("LeftOwner").is_none());
+        assert_eq!(number(back.get("HasBeenShot")), Some(0));
+        assert_eq!(
+            read_doubles::<3>(back.get("Motion")),
+            Some([0.0, -0.5, 1.0])
+        );
+        // A default fireball keeps vanilla's power and acceleration.
+        let plain = Tag::compound([
+            ("id", Tag::String("minecraft:fireball".into())),
+            ("Pos", doubles(&[0.0, 0.0, 0.0])),
+        ]);
+        let p = fireball_from_nbt(&plain, None).unwrap();
+        assert_eq!(
+            (p.kind, p.acceleration),
+            (ProjectileKind::LargeFireball { power: 1 }, 0.1)
+        );
+    }
+}

crates/horizon-client/src/extras.rs

@@ -1,7 +1,8 @@
 //! Horizon's optional extras (zoom, FPS counter, keystroke overlay): their
 //! settings, kept in `horizon-extras.txt` next to `options.txt` so that file
 //! stays exactly vanilla's, and the logic behind them. Every extra is off by
-//! default; see `docs/extras.md`.
+//! default; see `docs/extras.md`. Horizon's own switches outside the Extras page
+//! (No AI, Agent Control, Discord Rich Presence) are kept here too.
 use std::{collections::VecDeque, fs, path::Path};
 
 pub const FILE: &str = "horizon-extras.txt";
@@ -112,6 +113,8 @@ pub struct Extras {
     /// Agents may control the game the player starts: it opens its control socket for
     /// horizon-ctl and MCP clients (off by default; an agent's own launch always opens it).
     pub agent_control: bool,
+    /// "Playing Horizon" on the player's Discord profile (`discord_presence`; on by default).
+    pub discord_presence: bool,
 }
 impl Default for Extras {
     fn default() -> Self {
@@ -142,6 +145,7 @@ impl Default for Extras {
             sort_key: "key.keyboard.unknown".into(),
             no_ai: false,
             agent_control: false,
+            discord_presence: true,
         }
     }
 }
@@ -207,6 +211,7 @@ impl Extras {
                 "sortKey" if value.starts_with("key.") => e.sort_key = value.to_owned(),
                 horizon_core::no_ai::KEY => e.no_ai = flag(e.no_ai),
                 "agentControl" => e.agent_control = flag(e.agent_control),
+                "discordPresence" => e.discord_presence = flag(e.discord_presence),
                 _ => {}
             }
         }
@@ -214,7 +219,7 @@ impl Extras {
     }
     pub fn serialize(&self) -> String {
         format!(
-            "fullbright:{}\ndynamicLights:{}\nzoom:{}\nzoomKey:{}\nzoomLevel:{}\nzoomSmooth:{}\nzoomSensitivity:{}\nfps:{}\nfpsCorner:{}\nfpsLows:{}\nkeystrokes:{}\nkeystrokesCorner:{}\nkeystrokesCps:{}\nminimap:{}\nminimapCorner:{}\nminimapSize:{}\nminimapShape:{}\nminimapZoom:{}\nminimapRotate:{}\nautoReconnect:{}\nmouseTweaks:{}\nmouseTweaksWheel:{}\nsort:{}\nsortKey:{}\n{}:{}\nagentControl:{}\n",
+            "fullbright:{}\ndynamicLights:{}\nzoom:{}\nzoomKey:{}\nzoomLevel:{}\nzoomSmooth:{}\nzoomSensitivity:{}\nfps:{}\nfpsCorner:{}\nfpsLows:{}\nkeystrokes:{}\nkeystrokesCorner:{}\nkeystrokesCps:{}\nminimap:{}\nminimapCorner:{}\nminimapSize:{}\nminimapShape:{}\nminimapZoom:{}\nminimapRotate:{}\nautoReconnect:{}\nmouseTweaks:{}\nmouseTweaksWheel:{}\nsort:{}\nsortKey:{}\n{}:{}\nagentControl:{}\ndiscordPresence:{}\n",
             bool_text(self.fullbright),
             bool_text(self.dynamic_lights),
             bool_text(self.zoom),
@@ -246,6 +251,7 @@ impl Extras {
             horizon_core::no_ai::KEY,
             bool_text(self.no_ai),
             bool_text(self.agent_control),
+            bool_text(self.discord_presence),
         )
     }
     /// Binds the extra key `name` (`ZOOM_KEY`, `SORT_KEY`); false for
@@ -466,6 +472,8 @@ pub enum Item {
     /// Not on the Extras page: Horizon Settings shows No AI, its AI Agent page Agent Control.
     NoAi,
     AgentControl,
+    /// On the Horizon Settings page.
+    DiscordPresence,
 }
 /// The Extras page: headers and items.
 pub fn rows() -> Vec<Result<Item, &'static str>> {
@@ -546,6 +554,7 @@ impl Item {
             Item::KeystrokesCps => "Clicks per second",
             Item::NoAi => "No AI",
             Item::AgentControl => "Agent Control",
+            Item::DiscordPresence => "Discord Rich Presence",
         }
     }
     /// The switch this setting belongs to: it does nothing while that is off.
@@ -559,7 +568,7 @@ impl Item {
             MouseTweaksWheel => MouseTweaks,
             SortKey => Sort,
             Fullbright | DynamicLights | Zoom | Minimap | Fps | Keystrokes | MouseTweaks | Sort
-            | AutoReconnect | NoAi | AgentControl => {
+            | AutoReconnect | NoAi | AgentControl | DiscordPresence => {
                 return None;
             }
         })
@@ -606,6 +615,9 @@ impl Item {
             Item::NoAi => {
                 "Hides and turns off every AI feature: agent control, horizon-ctl and the MCP servers. The launcher's switch too."
             }
+            Item::DiscordPresence => {
+                "Shows Playing Horizon on your Discord profile while Discord runs: menus, single player or multiplayer, the dimension and the time played. Never a world's name or a server's address."
+            }
             Item::AgentControl => {
                 "Your own AI agent can play this game through horizon-ctl or an MCP client, on this computer only."
             }
@@ -641,6 +653,7 @@ impl Item {
             Item::Sort => e.sort,
             Item::NoAi => e.no_ai,
             Item::AgentControl => e.agent_control,
+            Item::DiscordPresence => e.discord_presence,
             _ => return None,
         })
     }
@@ -698,6 +711,7 @@ impl Item {
             Item::MinimapZoom => e.minimap_zoom = next(&MINIMAP_ZOOMS, e.minimap_zoom, back),
             Item::NoAi => e.no_ai = !e.no_ai,
             Item::AgentControl => e.agent_control = !e.agent_control,
+            Item::DiscordPresence => e.discord_presence = !e.discord_presence,
             Item::ZoomKey | Item::SortKey => {}
         }
     }
@@ -721,6 +735,7 @@ mod tests {
         assert!(!d.fullbright && !d.dynamic_lights);
         assert!(!d.zoom && !d.fps && !d.keystrokes && !d.minimap && !d.auto_reconnect);
         assert!(!d.mouse_tweaks && !d.sort);
+        assert!(d.discord_presence);
         assert_eq!(Extras::parse(""), d);
         assert_eq!(Extras::parse(&d.serialize()), d);
         let mut e = d.clone();
@@ -746,6 +761,7 @@ mod tests {
         e.mouse_tweaks_wheel = false;
         e.sort = true;
         e.sort_key = "key.keyboard.r".into();
+        e.discord_presence = false;
         assert_eq!(Extras::parse(&e.serialize()), e);
     }
 

crates/horizon-client/src/fog.rs

@@ -198,6 +198,8 @@ pub struct FogInputs<'a> {
     pub blindness: Option<(i32, bool)>,
     /// The darkness effect's blend factor, while the effect is on.
     pub darkness: Option<f32>,
+    /// `GameRenderer.bossOverlayWorldDarkening`: a wither's bar dims the fog.
+    pub darken_world: f32,
     /// `BossHealthOverlay.shouldCreateWorldFog`: a boss bar with
     /// `createWorldFog` is shown (the Ender Dragon's).
     pub boss_world_fog: bool,
@@ -263,6 +265,13 @@ pub fn setup_fog(tables: &FogTables, state: &FogState, input: &FogInputs) -> Fog
         let brightness = (1.0 - darkness) * (1.0 - darkness);
         color = color.map(|c| c * brightness);
     }
+    // FogRenderer.computeFogColor: a boss bar's world darkening.
+    if input.darken_world > 0.0 {
+        let t = input.darken_world;
+        color[0] += (color[0] * 0.7 - color[0]) * t;
+        color[1] += (color[1] * 0.6 - color[1]) * t;
+        color[2] += (color[2] * 0.6 - color[2]) * t;
+    }
     let brighten = if eye_in_water { water_vision } else { 0.0 };
     if color.iter().all(|&c| c != 0.0) {
         let scale = 1.0 / color[0].max(color[1]).max(color[2]);
@@ -394,6 +403,7 @@ mod tests {
             skybox: true,
             blindness: None,
             darkness: None,
+            darken_world: 0.0,
             boss_world_fog: false,
         }
     }
@@ -422,6 +432,25 @@ mod tests {
         assert_eq!(water.environmental_start, -8.0);
     }
     #[test]
+    fn boss_darkening_dims_fog_color() {
+        // FogRenderer.computeFogColor: lerp toward 70/60/60% of each channel.
+        let sky = Sky {
+            fog_color: [1.0, 1.0, 1.0],
+            sky_color: [1.0, 1.0, 1.0],
+            ..Sky::default()
+        };
+        let tables = FogTables {
+            water_fog_end: vec![1.0],
+        };
+        let mut input = inputs(&sky);
+        input.skybox = false;
+        input.darken_world = 1.0;
+        let fog = setup_fog(&tables, &FogState::default(), &input);
+        assert!((fog.color[0] - 0.7).abs() < 1.0e-5);
+        assert!((fog.color[1] - 0.6).abs() < 1.0e-5);
+        assert!((fog.color[2] - 0.6).abs() < 1.0e-5);
+    }
+    #[test]
     fn void_darkness_starts_32_above_the_floor() {
         let sky = Sky {
             fog_end: 1024.0,

crates/horizon-client/src/game.rs

@@ -13,6 +13,7 @@ mod block_entity_anims;
 mod block_entity_ticks;
 mod block_items;
 mod blockctl;
+mod boat_passengers;
 mod boats;
 mod books;
 mod bossbars;
@@ -35,6 +36,7 @@ mod debug_keys;
 mod decorated_pot;
 mod dedicated;
 mod deflect;
+mod discord;
 mod dispense_fixture;
 mod dispenser;
 mod dragon;
@@ -43,6 +45,7 @@ mod enchant_effects;
 mod end;
 mod entity_culling;
 mod events;
+mod execution_role;
 mod explosion;
 mod extras;
 mod falling_damage;
@@ -137,6 +140,7 @@ mod scoreboard;
 mod screens;
 mod sculk;
 mod sculk_fixture;
+mod server_packs;
 mod server_travel;
 mod shader_packs;
 mod shield;
@@ -153,6 +157,7 @@ mod storage;
 mod structures;
 mod subtitle_hud;
 mod sulfur_cubes;
+mod text_displays;
 mod titles;
 mod tnt;
 mod totem;
@@ -289,8 +294,8 @@ struct Options {
     /// as vanilla's does: the default. `--in-frame` (or `--no-server-thread`,
     /// or `HORIZON_SERVER_THREAD=0`) runs the world in the frame instead.
     server_thread: bool,
-    /// Set on the integrated server's own options: it draws nothing, so it skips meshing.
-    integrated: bool,
+    /// What this Game executes; independent of its current server connection.
+    execution_role: execution_role::ExecutionRole,
 }
 impl Options {
     /// The name to join servers with: the one given, else the offline name kept
@@ -347,7 +352,7 @@ impl Options {
             // itself, without the event loop: it stays in the frame.
             server_thread: std::env::var("HORIZON_SERVER_THREAD").map_or(true, |v| v != "0")
                 && std::env::var_os("HORIZON_COMMAND_SCRIPT").is_none(),
-            integrated: false,
+            execution_role: execution_role::ExecutionRole::Client,
         };
         let mut session_file = std::env::var("HORIZON_SESSION_FILE").ok();
         let mut args = std::env::args().skip(1);
@@ -361,6 +366,7 @@ impl Options {
                     return Ok(None);
                 }
                 "--dedicated" => {
+                    o.execution_role = execution_role::ExecutionRole::DedicatedServer;
                     o.dedicated = Some(args.by_ref().collect());
                     break;
                 }
@@ -1127,6 +1133,8 @@ struct Game<'a> {
     pending_entry: Option<PendingWorldEntry>,
     world_loader: Option<world_loading::WorldLoader>,
     pending_pack_reload: bool,
+    /// A server's resource packs (game/server_packs.rs).
+    server_packs: server_packs::ServerPackState,
     world_renderer_ready: bool,
     collision: &'a BlockCollisionRegistry<'a>,
     motion: &'a MotionResources,
@@ -1199,8 +1207,6 @@ struct Game<'a> {
     modifiers: winit::keyboard::ModifiersState,
     /// The window's fullscreen request and reported state.
     fullscreen: horizon_client::window::FullscreenState,
-    /// The selected Horizon shader pack (`game/shader_packs.rs`).
-    shader_packs: shader_packs::ShaderPacks,
     /// MouseHandler's accumulated look and wheel state.
     mouse: MouseLook,
     /// An agent moved the mouse (`mouse-move`) since the pointer was last
@@ -1421,6 +1427,8 @@ struct Game<'a> {
     dragon_model: Option<horizon_client::mobs::Part>,
     /// Map textures waiting for the next HUD batch to upload them.
     map_patches: Vec<horizon_client::font::Patch>,
+    text_displays: std::collections::HashMap<i32, text_displays::RemoteTextDisplay>,
+    text_display_vertices: usize,
     /// Player skin downloads, and which skin each atlas skin slot holds
     /// (least recently shown first).
     skin_downloads: RefCell<horizon_client::skins::Downloader>,
@@ -1565,6 +1573,8 @@ struct Game<'a> {
     score: scoreboard::ScoreState,
     fns: functions::FnState,
     bosses: bossbars::BossState,
+    /// `Hud.bossOverlay`: the bars this window is showing.
+    boss_overlay: horizon_client::boss_overlay::BossOverlay,
     exec: commands::execute::ExecState,
     rand_sequences: horizon_client::random_sequences::RandomSequences,
     border: horizon_client::worldborder::WorldBorder,
@@ -1741,10 +1751,10 @@ impl Game<'_> {
             let state = self.world.block(pos[0], pos[1], pos[2]);
             let f = self.res.facts().get(state);
             if !self.res.facts().is_air(state)
-                && !(f.fluid != Fluid::None
-                    && !f.waterlogged
-                    && &*f.name != "minecraft:kelp"
-                    && f.render_shape != horizon_client::blocks::RenderShape::Model)
+                && (f.fluid == Fluid::None
+                    || f.waterlogged
+                    || &*f.name == "minecraft:kelp"
+                    || f.render_shape == horizon_client::blocks::RenderShape::Model)
                 && !matches!(
                     &*f.name,
                     "minecraft:water" | "minecraft:lava" | "minecraft:bubble_column"
@@ -3510,7 +3520,7 @@ impl Game<'_> {
             return Ok(true);
         }
         // Block foods attempt placement before starting consumption.
-        if !on_block && !(info.block.is_some() && block_hit.is_some()) && self.start_eating(&info) {
+        if !on_block && (info.block.is_none() || block_hit.is_none()) && self.start_eating(&info) {
             return Ok(true);
         }
         // BoatItem.use also performs its own fluid/block raycast.
@@ -4045,6 +4055,20 @@ impl Game<'_> {
         self.capture_loaded_world();
         Ok(())
     }
+    /// Landing rules (farmland trampling, turtle eggs) wrote or removed the block
+    /// raw: finish `Level.setBlock`'s neighbour updates, so a crop on trampled
+    /// farmland breaks. The local player's and every server player's landings.
+    fn landing_block_updates(&mut self, event: &horizon_client::landing::FallEvent) {
+        use horizon_client::landing::FallEvent;
+        let (position, flags) = match *event {
+            FallEvent::Write {
+                position, flags, ..
+            } => (position, flags as i32),
+            FallEvent::Destroy { position, .. } => (position, level_flags::UPDATE_ALL),
+            _ => return,
+        };
+        self.with_level(|b, level, ticks| b.notify_written(level, ticks, position, flags));
+    }
     fn tick(&mut self) -> Result<()> {
         self.tick_debug_keys()?;
         self.tick_debug_charts();
@@ -4063,6 +4087,8 @@ impl Game<'_> {
         self.track_experience_display();
         // `/tick freeze` stops the world but not the player.
         let running = self.clock.world_runs();
+        // GameRenderer.tick: a wither's bar darkens the world, then fades.
+        self.boss_overlay.tick_darken(running);
         if running {
             self.world.game_time += 1;
             if self.ui.rules.bool("advance_weather") {
@@ -4102,7 +4128,7 @@ impl Game<'_> {
             self.tick_riding(keys)?;
         }
         let riding = self.riding.is_some();
-        let ghast_collisions = self.happy_ghast_player_collisions();
+        let entity_collisions = self.player_entity_collisions();
         let spin_targets = self.spin_targets();
         self.sync_player_body();
         let Some(player) = self.player.as_mut() else {
@@ -4149,7 +4175,7 @@ impl Game<'_> {
         );
         if !riding {
             MotionWorld {
-                entities: &ghast_collisions,
+                entities: &entity_collisions,
                 player,
                 scene: &mut self.world,
                 assets: &self.pack.assets,
@@ -4259,23 +4285,7 @@ impl Game<'_> {
                     };
                     self.audio.play(name, Some(feet), volume, pitch);
                 }
-                MotionEvent::Fall(horizon_client::landing::FallEvent::Write {
-                    position,
-                    flags,
-                    ..
-                }) => {
-                    // Landing rules (farmland trampling, turtle eggs) wrote the block raw.
-                    self.with_level(|b, level, ticks| {
-                        b.notify_written(level, ticks, position, flags as i32)
-                    });
-                }
-                MotionEvent::Fall(horizon_client::landing::FallEvent::Destroy {
-                    position, ..
-                }) => {
-                    self.with_level(|b, level, ticks| {
-                        b.notify_written(level, ticks, position, level_flags::UPDATE_ALL)
-                    });
-                }
+                MotionEvent::Fall(event) => self.landing_block_updates(&event),
                 MotionEvent::Snowflake { position, velocity } => self.snowflake(position, velocity),
                 MotionEvent::EnterBlock { state } => self.trigger_enter_block(state),
                 MotionEvent::InsidePortal { pos } => self.player_inside_nether_portal(pos),
@@ -4413,7 +4423,7 @@ impl Game<'_> {
                 self.resolve_arrivals();
             });
         }
-        horizon_client::spans::time("tick_lan", || self.tick_lan());
+        horizon_client::spans::time("tick_lan", || self.tick_lan(false));
         self.tick_friends();
         horizon_client::spans::time("tick_hand", || self.tick_hand());
         horizon_client::spans::time("tick_sleep", || self.tick_sleep());
@@ -4438,6 +4448,8 @@ impl Game<'_> {
             });
             horizon_client::spans::time("tick_particles", || self.tick_particles());
         }
+        // ServerBossEvent broadcasts, after this level's entities have ticked.
+        self.publish_boss_bars();
         // Minecraft.handleKeybinds: held use repeats only while no item is in
         // use (a raised shield or a drawn bow places and uses nothing).
         if self.right
@@ -4774,7 +4786,14 @@ impl Game<'_> {
         hud_layout::paint(batch, &self.gui.atlas, &draws);
     }
     fn hud(&mut self, size: [u32; 2]) -> HudBatch {
-        let mut batch = self.hud_layers(size);
+        // The pack prompt replaces the connecting screen (setScreen), but
+        // in game it opens over the world.
+        let mut batch = if self.server_packs.prompt.is_some() && self.player.is_none() {
+            HudBatch::new(size)
+        } else {
+            self.hud_layers(size)
+        };
+        self.draw_pack_prompt(&mut batch);
         // Gui.extractRenderState: the debug overlay comes after the screen
         // and the toasts, so it is over everything, menus included.
         self.draw_debug_overlay(&mut batch, size);
@@ -4811,11 +4830,15 @@ impl Game<'_> {
         }
         let atlas_ptr: *const HudAtlas = &self.gui.atlas;
         let _ = atlas_ptr;
+        // The ToastManager draws over every screen: a server's packs
+        // download while the connection screen shows.
         if self.remote_overlay(&mut batch) {
+            self.draw_pack_toasts(&mut batch);
             return batch;
         }
         if let Some(reason) = self.loading_reason() {
             self.draw_level_loading(&mut batch, reason);
+            self.draw_pack_toasts(&mut batch);
             return batch;
         }
         // Hud.extractRenderState: F1 (keyToggleGui) hides camera overlays, the
@@ -5027,6 +5050,7 @@ impl Game<'_> {
             Screen::Playing | Screen::Options | Screen::Win => {}
         }
         self.draw_toasts(&mut batch);
+        self.draw_pack_toasts(&mut batch);
         self.remote_hud(&mut batch);
         self.draw_sign_editor(&mut batch);
         self.draw_book(&mut batch);
@@ -6764,6 +6788,7 @@ impl Game<'_> {
         let mut see_through = std::mem::take(&mut self.see_through_vertices);
         see_through.clear();
         self.name_tag_geometry(camera, alpha, &mut out, &mut see_through);
+        self.text_display_geometry(camera, alpha, &mut out, &mut see_through);
         self.see_through_vertices = see_through;
         // Entity shadows (EntityRenderer.extractShadow).
         if let Some(sprite) = self.gui.atlas.sprites.get("misc/shadow").copied() {
@@ -7434,30 +7459,17 @@ impl Game<'_> {
         self.tick_player_model();
         Ok(())
     }
-    /// What the loaded Java shader pack changes in this dimension's vanilla
-    /// sky (`sunPathRotation`, `clouds`, `sun`, `moon`); `None` without one.
-    fn java_sky(&self) -> Option<(f32, horizon_shaderpack::properties::SkyDirectives)> {
-        self.shader_packs.java_sky(match self.dim {
-            Dim::Overworld => 0,
-            Dim::Nether => -1,
-            Dim::End => 1,
-        })
-    }
     /// SkyRenderer.renderSunMoonAndStars: bodies on a frame rotated Y -90 then X by angle.
-    /// A Java pack's `sunPathRotation` tilts it about Z in between, and its
-    /// `sun = false` / `moon = false` leave those out, as Iris does. Returns
-    /// the sun and moon quads, and the stars' frame and brightness (the
-    /// renderer keeps their geometry, built once).
+    /// Returns the sun and moon quads, and the stars' frame and brightness
+    /// (the renderer keeps their geometry, built once).
     fn celestial_geometry(
         &self,
         sky: &horizon_client::environment::Sky,
     ) -> (Vec<Vertex>, Option<(glam::Mat4, f32)>) {
         let mut out = Vec::new();
         let atlas = &self.gui.atlas;
-        let (tilt, keep) = self.java_sky().unwrap_or_default();
         let frame = |angle: f32| {
             glam::Mat4::from_rotation_y((-90.0f32).to_radians())
-                * glam::Mat4::from_rotation_z(tilt.to_radians())
                 * glam::Mat4::from_rotation_x(angle.to_radians())
         };
         let mut body = |name: &str, angle: f32, size: f32, color: u32| {
@@ -7479,14 +7491,12 @@ impl Game<'_> {
                 });
             }
         };
-        if keep.sun {
-            body(
-                "environment/celestial/sun",
-                sky.sun_angle,
-                30.0,
-                0xFFFF_FFFF,
-            );
-        }
+        body(
+            "environment/celestial/sun",
+            sky.sun_angle,
+            30.0,
+            0xFFFF_FFFF,
+        );
         let phases = [
             "full_moon",
             "waning_gibbous",
@@ -7498,20 +7508,18 @@ impl Game<'_> {
             "waxing_gibbous",
         ];
         let phase = phases[(self.world.day_time / 24000).rem_euclid(8) as usize];
-        if keep.moon {
-            body(
-                &format!("environment/celestial/moon/{phase}"),
-                sky.moon_angle,
-                20.0,
-                0xFFFF_FFFF,
-            );
-        }
+        body(
+            &format!("environment/celestial/moon/{phase}"),
+            sky.moon_angle,
+            20.0,
+            0xFFFF_FFFF,
+        );
         // SkyRenderer.renderStars: the static star buffer on the same frame.
         let stars =
             (sky.star_brightness > 0.0).then(|| (frame(sky.star_angle), sky.star_brightness));
         (out, stars)
     }
-    /// Load (or create) a world folder under saves/ and start streaming it.
+    /// Enter a local world from the client, selecting its simulation mode.
     fn open_world(
         &mut self,
         folder: &str,
@@ -7530,20 +7538,16 @@ impl Game<'_> {
             return Ok(());
         }
         self.join_world_rest()?;
-        let save_root = std::env::current_dir()?.join("saves").join(folder);
-        if integrated::wanted(&self.options, &save_root) {
+        if self
+            .options
+            .execution_role
+            .starts_integrated_server(self.options.server_thread)
+        {
             return self.open_integrated(folder, name, seed, creative, create);
         }
-        self.perf.world_opening();
-        let request = world_loading::WorldRequest {
-            save_root,
-            folder: folder.to_owned(),
-            name: name.map(str::to_owned),
-            seed,
-            creative,
-            create: create.cloned(),
-        };
+        let request = world_loading::WorldRequest::new(folder, name, seed, creative, create)?;
         if self.window.is_some() {
+            self.perf.world_opening();
             if self.title.is_none() {
                 self.title = Some(Title::new(
                     std::env::current_dir()?.join("saves"),
@@ -7559,6 +7563,14 @@ impl Game<'_> {
             )?);
             return Ok(());
         }
+        self.load_world(request)
+    }
+
+    /// Load authoritative world state synchronously, without client entry or
+    /// integrated-server selection. Server startup must use this entry point.
+    fn load_world(&mut self, request: world_loading::WorldRequest) -> Result<()> {
+        self.join_world_rest()?;
+        self.perf.world_opening();
         let prepared = request.prepare(&self.res, &self.pack, &self.options, &self.settings)?;
         self.finish_open_world(prepared)
     }
@@ -7972,6 +7984,8 @@ impl Game<'_> {
         self.session_lock = None;
         horizon_client::crash::clear_detail("World");
         self.debug_charts.reset();
+        self.boss_overlay.reset();
+        self.bosses = Default::default();
         self.streaming.paused = true;
         self.world = World::new(self.res.facts().air, 0);
         self.player = None;
@@ -9100,21 +9114,11 @@ impl Game<'_> {
         // Options.biomeBlendRadius, ambientOcclusion and cutoutLeaves:
         // LevelExtractor.allChanged when they change.
         let (s, st) = (&self.settings, &self.streaming);
-        let remesh = (
-            s.biome_blend,
-            s.smooth_lighting,
-            s.cutout_leaves,
-            s.horizon.cull_leaves,
-        ) != (
-            st.biome_blend,
-            st.smooth_lighting,
-            st.cutout_leaves,
-            st.cull_leaves,
-        );
+        let remesh = (s.biome_blend, s.smooth_lighting, s.cutout_leaves)
+            != (st.biome_blend, st.smooth_lighting, st.cutout_leaves);
         self.streaming.biome_blend = self.settings.biome_blend;
         self.streaming.smooth_lighting = self.settings.smooth_lighting;
         self.streaming.cutout_leaves = self.settings.cutout_leaves;
-        self.streaming.cull_leaves = self.settings.horizon.cull_leaves;
         if remesh {
             self.all_sections_changed();
         }
@@ -9560,13 +9564,13 @@ impl Game<'_> {
                 let (x, y) = (ox + 9.0 + c as f32 * 18.0, oy + 112.0);
                 let stack = self.inventory[c].clone();
                 self.draw_slot_item(batch, drag.as_ref(), c, stack.clone(), x, y);
-                if let Some(stack) = stack
-                    && self.cursor.0 >= x
+                if self.cursor.0 >= x
                     && self.cursor.0 < x + 16.0
                     && self.cursor.1 >= y
                     && self.cursor.1 < y + 16.0
                 {
-                    hovered = Some(stack);
+                    batch.fill(&self.gui.atlas, x, y, 16.0, 16.0, rgba(255, 255, 255, 128));
+                    hovered = stack;
                 }
             }
             let scrollable = self.creative_screen.rows(&self.pack.names) > 5;
@@ -9831,7 +9835,6 @@ impl Game<'_> {
             }
             return Ok(false);
         }
-        self.poll_shader_pack();
         let Some(size) = self
             .renderer
             .as_ref()
@@ -10044,18 +10047,6 @@ impl Game<'_> {
             self.dragon_fireball_geometry(camera, alpha, &mut dragon);
             entities.extend(dragon);
         }
-        // A Java pack's `clouds` replaces the cloud option (`renderClouds`:
-        // "false", "fast", "true"), as Iris overrides `getCloudsType`.
-        let clouds_mode = {
-            use horizon_shaderpack::properties::CloudSetting;
-            match self.java_sky().and_then(|(_, sky)| sky.clouds) {
-                Some(CloudSetting::Off) => "false",
-                Some(CloudSetting::Fast) => "fast",
-                Some(CloudSetting::Fancy) => "true",
-                None => self.settings.clouds.as_str(),
-            }
-            .to_owned()
-        };
         let (celestial, stars) = if title {
             (Vec::new(), None)
         } else if self.dim == Dim::Overworld
@@ -10096,10 +10087,14 @@ impl Game<'_> {
         } else {
             self.gather_dynamic_lights(camera, alpha);
         }
+        let pack_inputs = if title {
+            Default::default()
+        } else {
+            self.shader_pack_inputs(camera, alpha as f32)
+        };
         let frame = Frame {
             weather: &weather,
             weather_time: horizon_client::weather::Time::new(self.world.game_time, alpha as f32),
-            shader: self.shader_inputs(camera, alpha as f32),
             nether_lighting: self.dim == Dim::Nether,
             camera,
             yaw,
@@ -10129,7 +10124,7 @@ impl Game<'_> {
                 if !self.settings.horizon.fog
                     && !underwater
                     && self.darkness_fog().is_none()
-                    && !self.dragon_bar_shown()
+                    && !self.boss_overlay.should_create_world_fog()
                     && self.potions.effects.get("blindness").is_none()
                     && fog.environmental_end >= (self.streaming.radius * 16) as f32
                 {
@@ -10147,7 +10142,7 @@ impl Game<'_> {
             hud: &hud,
             clouds: (!title
                 && self.dim == Dim::Overworld
-                && horizon_client::clouds::visible(&clouds_mode, sky.cloud_color[3]))
+                && horizon_client::clouds::visible(&self.settings.clouds, sky.cloud_color[3]))
             .then(|| self.gui.atlas.sprites.get("horizon/white"))
             .flatten()
             .map(|white| horizon_client::clouds::Input {
@@ -10157,7 +10152,7 @@ impl Game<'_> {
                 time: self.world.game_time,
                 partial_tick: alpha,
                 range: self.settings.cloud_range,
-                fast: clouds_mode == "fast",
+                fast: self.settings.clouds == "fast",
                 color: sky.cloud_color,
             }),
             entities: &entities,
@@ -10180,6 +10175,7 @@ impl Game<'_> {
             hand: &hand,
             hand_fov_degrees: self.hud_fov_degrees(camera_alpha as f32, camera.to_array()),
             screen: &screen,
+            pack: pack_inputs,
             border,
             game_time: self.world.game_time as f32,
             shader_game_time: ((self.world.game_time % 24000) as f32 + alpha as f32) / 24000.0,
@@ -10200,6 +10196,9 @@ impl Game<'_> {
             darkness: self.darkness_lighting(alpha as f32),
             night_vision: self.night_vision_intensity(),
             block_flicker: self.fog.block_light_flicker,
+            boss_darken: self
+                .boss_overlay
+                .darken_amount(self.clock.fraction() as f32),
             menu_blur: self.menu_blur(),
         };
         let result = match self.renderer.as_mut() {
@@ -10590,7 +10589,7 @@ impl Game<'_> {
         }
         // The loading screen's chunk map fills ring by ring, as vanilla's.
         self.streaming.loading =
-            self.options.dedicated.is_none() && self.loading_reason().is_some();
+            self.options.execution_role.is_client() && self.loading_reason().is_some();
         let (uploads, unloaded) =
             horizon_client::spans::time("streaming", || self.streaming.update(&mut self.world));
         if let Some(lod) = &mut self.lod {
@@ -10875,9 +10874,6 @@ impl ApplicationHandler for Game<'_> {
                 WindowEvent::CloseRequested => {
                     self.pending_save.as_mut().unwrap().quit = true;
                 }
-                WindowEvent::DroppedFile(path) => {
-                    self.drop_shader_pack(&path);
-                }
                 WindowEvent::Focused(focused) => {
                     self.focused = focused;
                     if !focused {
@@ -11032,6 +11028,13 @@ impl ApplicationHandler for Game<'_> {
                         self.advancements_scroll(scaled(raw_x) as f32, d);
                     }
                 }
+                WindowEvent::MouseInput { state, button, .. }
+                    if self.server_packs.prompt.is_some() =>
+                {
+                    if state == ElementState::Pressed && button == MouseButton::Left {
+                        self.pack_prompt_click()?;
+                    }
+                }
                 WindowEvent::MouseInput { .. } if self.screen == Screen::Win => {}
                 WindowEvent::MouseInput { state, button, .. } if self.screen == Screen::Options => {
                     if self.options_waiting_for_key() && state == ElementState::Pressed {
@@ -11231,6 +11234,14 @@ impl ApplicationHandler for Game<'_> {
                         _ => {}
                     }
                 }
+                // ConfirmScreen.keyPressed: Escape answers no.
+                WindowEvent::KeyboardInput { event, .. } if self.server_packs.prompt.is_some() => {
+                    if event.state == ElementState::Pressed
+                        && event.physical_key == PhysicalKey::Code(KeyCode::Escape)
+                    {
+                        self.answer_pack_prompt(false)?;
+                    }
+                }
                 WindowEvent::KeyboardInput { event, .. }
                     if self.screen == Screen::Chat && self.title.is_none() =>
                 {
@@ -11415,6 +11426,7 @@ impl ApplicationHandler for Game<'_> {
                     self.track_toggle_screens();
                     // For the "I'm playing" ping: an atomic, sent on when it changes.
                     horizon_client::heartbeat::set_lan(self.is_published());
+                    self.update_discord_presence();
                     let steps = self.clock.advance(elapsed);
                     // The world ticking in the frame: once its ticks took a
                     // tick's length, the rest are dropped (`FixedStep::tick_fits`).
@@ -11609,6 +11621,7 @@ impl ApplicationHandler for Game<'_> {
             event_loop.exit();
             return;
         }
+        self.tick_server_packs();
         self.poll_control(event_loop);
         if self.pending_save.is_some() {
             return;
@@ -11703,6 +11716,7 @@ impl<'a> Game<'a> {
             pending_entry: None,
             world_loader: None,
             pending_pack_reload: false,
+            server_packs: Default::default(),
             world_renderer_ready: false,
             collision: res.collision(),
             motion: res.motion(),
@@ -11760,7 +11774,6 @@ impl<'a> Game<'a> {
             focused: true,
             modifiers: winit::keyboard::ModifiersState::empty(),
             fullscreen: horizon_client::window::FullscreenState::new(false),
-            shader_packs: Default::default(),
             mouse: MouseLook::default(),
             agent_pointer: false,
             smooth_camera: false,
@@ -11904,6 +11917,8 @@ impl<'a> Game<'a> {
             breath_clouds: Vec::new(),
             dragon_model: prepared.dragon_model,
             map_patches: Vec::new(),
+            text_displays: Default::default(),
+            text_display_vertices: 0,
             skin_downloads: RefCell::new(horizon_client::skins::Downloader::new(
                 std::env::current_dir()
                     .unwrap_or_default()
@@ -11991,6 +12006,7 @@ impl<'a> Game<'a> {
             score: Default::default(),
             fns: Default::default(),
             bosses: Default::default(),
+            boss_overlay: Default::default(),
             exec: Default::default(),
             rand_sequences: Default::default(),
             border: Default::default(),
@@ -12082,6 +12098,8 @@ enum PendingWorldEntry {
     Server {
         address: String,
         name: String,
+        /// A transfer's carried-over server cookies (`TransferState`).
+        cookies: Option<horizon_client::net::Cookies>,
     },
 }
 
@@ -12156,8 +12174,12 @@ impl Game<'_> {
             }) => {
                 self.open_world(&folder, name.as_deref(), seed, creative, create.as_deref())?;
             }
-            Some(PendingWorldEntry::Server { address, name }) => {
-                self.connect_server(&address, &name)?;
+            Some(PendingWorldEntry::Server {
+                address,
+                name,
+                cookies,
+            }) => {
+                self.connect_server_with_cookies(&address, &name, cookies)?;
             }
             None => {}
         }
@@ -12264,7 +12286,7 @@ fn synchronous_startup(options: &Options) -> bool {
         || options.world_frames.is_some()
         || options.benchmark.is_some()
         || options.control.is_some()
-        || options.dedicated.is_some()
+        || !options.execution_role.is_client()
         || std::env::var_os("HORIZON_DISPENSE_FIXTURE").is_some()
         || std::env::var_os("HORIZON_SCULK_FIXTURE").is_some()
         || std::env::var_os("HORIZON_COMMAND_SCRIPT").is_some()
@@ -12709,6 +12731,7 @@ fn loading_frame(hud: &HudBatch) -> Frame<'_> {
         hand: &[],
         hand_fov_degrees: 70.0,
         screen: &[],
+        pack: Default::default(),
         border: None,
         game_time: 0.0,
         shader_game_time: 0.0,
@@ -12718,8 +12741,8 @@ fn loading_frame(hud: &HudBatch) -> Frame<'_> {
         darkness: (0.0, 0.0),
         night_vision: 0.0,
         block_flicker: 0.0,
+        boss_darken: 0.0,
         menu_blur: None,
-        shader: Default::default(),
     }
 }
 
@@ -12806,7 +12829,7 @@ fn start_game<'a>(
         game.sculk_fixture(&spec)?;
         return Ok(None);
     }
-    if game.options.dedicated.is_some() {
+    if game.options.execution_role == execution_role::ExecutionRole::DedicatedServer {
         game.run_dedicated()?;
         return Ok(None);
     }
@@ -12881,6 +12904,7 @@ fn write_report(game: &Game<'_>) -> Result<()> {
 
 fn run_event_loop(mut game: Game<'_>) -> Result<()> {
     EventLoop::new()?.run_app(&mut game)?;
+    horizon_client::discord_presence::stop();
     write_report(&game)?;
     if let Some(e) = game.error.take() {
         return Err(e);
@@ -13083,7 +13107,7 @@ impl Loading {
         );
         let renderer_ms = renderer_at.elapsed().as_millis();
         // Audio is created on the main thread, after the core is ready.
-        let audio = if options.dedicated.is_some() {
+        let audio = if !options.execution_role.is_client() {
             Audio::silent(&options.resources)
         } else {
             Audio::new(&options.resources)
@@ -13238,6 +13262,7 @@ fn run_loading(
     };
     let mut app = App::Loading(Box::new(loading));
     EventLoop::new()?.run_app(&mut app)?;
+    horizon_client::discord_presence::stop();
     match app {
         App::Ready(mut game) => {
             write_report(&game)?;
@@ -13258,13 +13283,15 @@ pub fn run() -> Result<()> {
     let Some(mut options) = Options::read()? else {
         return Ok(());
     };
-    if options.dedicated.is_some() && !dedicated::preflight(&mut options)? {
+    if options.execution_role == execution_role::ExecutionRole::DedicatedServer
+        && !dedicated::preflight(&mut options)?
+    {
         return Ok(());
     }
     // Before any worker starts: on Linux they go behind the server thread
     // and the render thread.
     horizon_threads::put_helpers_behind();
-    if options.dedicated.is_none() {
+    if options.execution_role.is_client() {
         // The render thread, like the server thread, ahead of the workers on
         // macOS and Windows. While terrain loads, the worker pools (two with
         // single player's server thread) and other programs outnumber the
@@ -13274,7 +13301,7 @@ pub fn run() -> Result<()> {
     }
     // Someone is playing: the anonymous ping behind the launcher's "N playing now". Not for a
     // server, a benchmark or a run that quits by itself.
-    if options.dedicated.is_none()
+    if options.execution_role.is_client()
         && options.benchmark.is_none()
         && !options.offscreen
         && options.frames.is_none()
@@ -13286,6 +13313,14 @@ pub fn run() -> Result<()> {
     horizon_client::spans::enable(options.spikes.is_some());
     let vanilla_root = options.resources.clone();
     let early_settings = Settings::load(&std::env::current_dir()?.join("options.txt"));
+    // "Playing Horizon" on Discord: never for a server; an automated run only talks to a test's fake Discord.
+    if options.dedicated.is_none() {
+        let automated = options.benchmark.is_some()
+            || options.offscreen
+            || options.frames.is_some()
+            || options.world_frames.is_some();
+        horizon_client::discord_presence::start(early_settings.extras.discord_presence, automated);
+    }
     // Snapshots of derived tables live in the game folder, never beside the
     // shared resources.
     Behaviours::set_cache_dir(std::env::current_dir()?.join(".horizon-cache"));
@@ -13293,7 +13328,7 @@ pub fn run() -> Result<()> {
         return run_loading(options, early_settings, vanilla_root, None, started);
     }
     let mut pack_error = None;
-    options.resources = packs::startup_root(&vanilla_root, &early_settings.resource_packs)
+    options.resources = packs::startup_root(&vanilla_root, &early_settings.resource_packs, &[])
         .unwrap_or_else(|e| {
             log::warn!("Horizon: resource packs not applied: {e}");
             pack_error = Some(e.to_string());
@@ -13315,7 +13350,7 @@ pub fn run() -> Result<()> {
     )?;
     let gui = loaded.gui.ok_or("missing menu bundle")?;
     options.resources = loaded.root.clone();
-    let audio = if options.dedicated.is_some() {
+    let audio = if !options.execution_role.is_client() {
         Audio::silent(&options.resources)
     } else {
         Audio::new(&options.resources)

crates/horizon-client/src/game/advancements.rs

@@ -881,30 +881,40 @@ pub(super) fn adv_name(a: &adv::Advancement) -> Text {
     let Some(d) = &a.display else {
         return Text::literal(a.id.clone());
     };
-    let color = match d.frame {
-        Frame::Challenge => text::DARK_PURPLE,
-        _ => text::GREEN,
-    };
-    // Advancement.decorateName: the title in the frame's colour (styles
-    // merged into it), a new line and the description.
-    let coloured = text_of(&d.title).with_color(color);
-    let mut component = coloured.component();
-    if let Some(o) = component.as_object_mut() {
-        o.insert(
-            "extra".into(),
-            serde_json::json!(["\n", text_of(&d.description).component()]),
-        );
-    }
-    let tooltip = coloured
-        .append("\n")
-        .append(text_of(&d.description))
-        .with_component(component);
+    let color = frame_color(d.frame);
     let title = text_of(&d.title).with_style(&Style {
-        hover: Some(Box::new(tooltip)),
+        hover: Some(Box::new(decorate_name(d))),
         ..Style::default()
     });
     Text::translate("chat.square_brackets", &[title]).with_color(color)
 }
+fn frame_color(frame: Frame) -> u32 {
+    match frame {
+        Frame::Challenge => text::DARK_PURPLE,
+        _ => text::GREEN,
+    }
+}
+/// `Advancement.decorateName`: a copy of the title with the frame's colour
+/// under its own style (mergeStyles), then a new line and the description
+/// after the title's own siblings, so both inherit the title's root style.
+/// Built on the title's JSON (a list as its first element with the rest as
+/// siblings): a parsed Text moves a styled root's style down a level once it
+/// has siblings.
+fn decorate_name(d: &adv::Display) -> Text {
+    let mut component = match horizon_client::scoreboard::canonical_component(&d.title) {
+        Value::String(s) => serde_json::json!({ "text": s }),
+        c => c,
+    };
+    if let Some(o) = component.as_object_mut() {
+        let frame = Text::empty().with_color(frame_color(d.frame)).component();
+        o.entry("color").or_insert_with(|| frame["color"].clone());
+        let extra = o.entry("extra").or_insert_with(|| serde_json::json!([]));
+        if let Some(extra) = extra.as_array_mut() {
+            extra.extend(["\n".into(), d.description.clone()]);
+        }
+    }
+    text_of(&component).with_component(component)
+}
 impl Game<'_> {
     /// `AdvancementCommands.Action.GRANT` on one advancement (or one of
     /// its criteria): false when nothing changed.
@@ -1051,17 +1061,10 @@ impl Game<'_> {
         }
     }
 }
-/// A text component from advancement JSON (`translate` or `text`).
+/// An advancement's title or description: a whole component (ComponentSerialization.CODEC),
+/// with its siblings and styles, as a plugin's `{"text":"","extra":[...]}` needs.
 pub(super) fn text_of(v: &Value) -> Text {
-    if let Some(key) = v["translate"].as_str() {
-        Text::translate(key, &[])
-    } else if let Some(s) = v["text"].as_str() {
-        Text::literal(s)
-    } else if let Some(s) = v.as_str() {
-        Text::literal(s)
-    } else {
-        Text::empty()
-    }
+    horizon_client::scoreboard::comp_text(v)
 }
 
 #[cfg(test)]
@@ -1095,6 +1098,105 @@ mod tests {
         (seen, None)
     }
 
+    #[test]
+    fn titles_keep_their_siblings_and_styles() {
+        let title = text_of(&serde_json::json!({
+            "text": "",
+            "extra": [{"text": "Quest ", "color": "gold"}, "Board"],
+        }));
+        assert_eq!(title.plain(), "Quest Board");
+        assert_eq!(title.spans[0].style.color, Some(text::GOLD));
+        assert_eq!(title.spans[1].style.color, None);
+        let vanilla = text_of(&serde_json::json!({"translate": "advancements.story.root.title"}));
+        assert_eq!(
+            vanilla,
+            Text::translate("advancements.story.root.title", &[])
+        );
+        assert_eq!(
+            vanilla.translation_key(),
+            Some("advancements.story.root.title")
+        );
+    }
+
+    fn announced(title: Value, description: Value) -> adv::Advancement {
+        adv::Advancement {
+            id: "quests:board".into(),
+            parent: None,
+            display: Some(adv::Display {
+                icon: "minecraft:book".into(),
+                title,
+                description,
+                frame: Frame::Task,
+                background: None,
+                show_toast: true,
+                announce: true,
+                hidden: false,
+            }),
+            criteria: Vec::new(),
+            requirements: Vec::new(),
+            rewards: adv::Rewards::default(),
+        }
+    }
+    /// The chat hover: the JSON a client receives, and the spans drawn here.
+    fn hover(a: &adv::Advancement) -> (Value, Text) {
+        let local = decorate_name(a.display.as_ref().unwrap());
+        let sent = adv_name(a).component()["with"][0]["hover_event"]["value"].clone();
+        (sent, local)
+    }
+
+    #[test]
+    fn chat_hover_keeps_the_titles_siblings_before_the_description() {
+        let a = announced(
+            serde_json::json!({"text": "", "extra": [{"text": "Quest ", "color": "gold"}, "Board"]}),
+            serde_json::json!("Open the board"),
+        );
+        let (sent, local) = hover(&a);
+        let sent = horizon_client::scoreboard::comp_text(&sent);
+        assert_eq!(sent.plain(), "Quest Board\nOpen the board");
+        let colors = |t: &Text| t.spans.iter().map(|s| s.style.color).collect::<Vec<_>>();
+        let (gold, green) = (Some(text::GOLD), Some(text::GREEN));
+        assert_eq!(colors(&sent), [gold, green, green, green]);
+        // The spans drawn here come from the same JSON a client receives.
+        assert_eq!(colors(&local), colors(&sent));
+    }
+
+    #[test]
+    fn chat_hover_description_takes_a_styled_titles_own_style() {
+        // mergeStyles keeps the title's gold; the description inherits it.
+        let object = announced(
+            serde_json::json!({"text": "Quest", "color": "gold", "bold": true, "extra": [" Board"]}),
+            serde_json::json!("Open the board"),
+        );
+        let list = announced(
+            serde_json::json!([{"text": "Quest", "color": "gold", "bold": true}, " Board"]),
+            serde_json::json!("Open the board"),
+        );
+        for a in [object, list] {
+            let (sent, local) = hover(&a);
+            let sent = horizon_client::scoreboard::comp_text(&sent);
+            assert_eq!(sent.plain(), "Quest Board\nOpen the board");
+            let last = &sent.spans.last().unwrap().style;
+            assert_eq!((last.color, last.bold), (Some(text::GOLD), Some(true)));
+            assert_eq!(local.spans.last().unwrap().style, *last);
+        }
+    }
+
+    #[test]
+    fn chat_hover_of_a_vanilla_advancement() {
+        let a = announced(
+            serde_json::json!({"translate": "advancements.story.root.title"}),
+            serde_json::json!({"translate": "advancements.story.root.description"}),
+        );
+        assert_eq!(
+            hover(&a).0,
+            serde_json::json!({
+                "translate": "advancements.story.root.title",
+                "color": "green",
+                "extra": ["\n", {"translate": "advancements.story.root.description"}],
+            })
+        );
+    }
+
     #[test]
     fn toasts_slide_in_squared_and_out_after_five_seconds() {
         let mut toast = recipes(1);

crates/horizon-client/src/game/agent.rs

@@ -9,6 +9,10 @@ use horizon_client::{
     block_entity_anim::Ticker,
     chunk::{MIN_Y, SECTIONS},
     items::ItemStack,
+    mobs::{
+        Species,
+        render::{PROFESSIONS, VILLAGER_TYPES},
+    },
     widgets,
 };
 use horizon_core::geometry::Vec3;
@@ -465,9 +469,12 @@ impl Game<'_> {
                 "flying": p.flying,
                 "fall_flying": p.fall_flying,
                 "sneaking": self.keys.contains(&KeyCode::ShiftLeft),
-                "sprinting": self.keys.contains(&KeyCode::ControlLeft),
+                "sprinting": p.sprinting,
+                "fov_modifier": self.view.fov_modifier,
                 "health": p.health.health(),
                 "absorption": p.health.absorption(),
+                // The hurt animation's ticks left (the camera's hurt tilt).
+                "hurt_time": p.health.hurt_animation_time,
                 "air": p.air,
                 "food": p.health.food.food,
                 "saturation": p.health.food.saturation,
@@ -592,10 +599,20 @@ impl Game<'_> {
             }
         };
         for m in self.mobs.iter().filter(|m| m.alive()) {
+            let mut v = json!({ "id": m.id, "kind": "mob", "health": m.health, "baby": m.is_baby(), "hurt_time": m.hurt_time });
+            // VillagerData as this game knows it: on a client, what the
+            // server's synched data says.
+            if matches!(m.species(), Species::Villager | Species::ZombieVillager) {
+                v["villager"] = json!({
+                    "type": VILLAGER_TYPES[m.extra.variant as usize % VILLAGER_TYPES.len()],
+                    "profession": PROFESSIONS[m.extra.variant2 as usize % PROFESSIONS.len()],
+                    "level": m.extra.variant3,
+                });
+            }
             push(
                 [m.position.x, m.position.y, m.position.z],
                 m.kind.id.as_ref(),
-                json!({ "id": m.id, "kind": "mob", "health": m.health, "baby": m.is_baby(), "hurt_time": m.hurt_time }),
+                v,
             );
         }
         for item in &self.dropped {

crates/horizon-client/src/game/blockctl.rs

@@ -59,6 +59,30 @@ impl Game<'_> {
     }
     /// Block commands; None when `words[0]` is not one of them.
     pub(super) fn block_command(&mut self, words: &[&str]) -> Result<Option<Value>> {
+        let ours = matches!(
+            words.first(),
+            Some(&("setblock" | "fill" | "getblock" | "container"))
+        );
+        // Single player on its server thread: the world is the server's, so
+        // the command runs there, in the owner's level, and the client hears
+        // of it like any change.
+        if ours && let Some(server) = &self.integrated {
+            let owned: Vec<String> = words.iter().map(|w| (*w).to_owned()).collect();
+            return server
+                .call(move |g| {
+                    let words: Vec<&str> = owned.iter().map(String::as_str).collect();
+                    g.in_owner_level(|g| g.block_command(&words).map_err(|e| e.to_string()))
+                })
+                .ok_or("the integrated server stopped")?
+                .map_err(Into::into);
+        }
+        // Another server's world changes only through its own commands, which
+        // it checks as the player's; `getblock` and `container` read what this
+        // client has of it.
+        if self.remote.is_some() && matches!(words.first(), Some(&("setblock" | "fill"))) {
+            self.send_chat(&format!("/{}", words.join(" ")));
+            return Ok(Some(json!({ "ok": true, "sent": true })));
+        }
         let int = |i: usize| -> Result<i32> {
             Ok(words
                 .get(i)

crates/horizon-client/src/game/boat_passengers.rs

@@ -0,0 +1,453 @@
+//! Boats and the entities around them: what a boat runs into
+//! (`AbstractBoat.canVehicleCollide`), the pushes between a boat and what
+//! touches it (`AbstractBoat.push`, `LivingEntity.pushEntities`), the mobs
+//! it picks up (the end of `AbstractBoat.tick`), where they sit
+//! (`positionRider`, `clampRotation`) and how they get out.
+//! Saving them under the boat's `Passengers` lives in `persist.rs`.
+use super::{Game, boats::Boat, lan_mobs::guest_bounds};
+use horizon_client::{
+    camera::wrap_degrees,
+    mobs::{Mob, Species, Who, drops::is_animal, equine, riders},
+    scoreboard::pushable_by,
+};
+use horizon_core::geometry::{Aabb, Vec3};
+
+/// `Entity.boardingCooldown` once a mob leaves its boat.
+const BOARDING_COOLDOWN: i32 = 60;
+/// `Player.DEFAULT_VEHICLE_ATTACHMENT`: how far below the seat a player's
+/// feet are.
+const PLAYER_RIDING_OFFSET: f64 = 0.6;
+
+/// `Entity.isVehicle`: a player or a mob rides it.
+fn carries(m: &Mob) -> bool {
+    m.rider.is_some() || m.extra.rider.is_some()
+}
+/// `isPushable`, as `pushableBy` and `canVehicleCollide` ask it:
+/// `Mob::pushable` plus the shulkers it leaves out (they take no push, but
+/// count), less a ridden horse (`AbstractHorse.isPushable`).
+fn pushable(m: &Mob) -> bool {
+    !m.removed
+        && (m.pushable() || m.species() == Species::Shulker && m.alive())
+        && !(equine::is_equine(m.species()) && carries(m))
+}
+/// Whether `Entity.push` moves the mob: it is pushable and carries no one.
+fn moved_by_push(m: &Mob) -> bool {
+    !m.removed && m.pushable() && !carries(m)
+}
+/// `Entity.push(Entity)`: the push `other` gets from `this` (which takes the
+/// opposite one), or None when they stand on nearly the same spot.
+pub(super) fn push_impulse(this: Vec3, other: Vec3) -> Option<Vec3> {
+    let (mut xa, mut za) = (other.x - this.x, other.z - this.z);
+    let mut dd = xa.abs().max(za.abs());
+    if dd < f64::from(0.01_f32) {
+        return None;
+    }
+    dd = dd.sqrt();
+    xa /= dd;
+    za /= dd;
+    let pow = (1.0 / dd).min(1.0);
+    let k = f64::from(0.05_f32);
+    Some(Vec3::new(xa * pow * k, 0.0, za * pow * k))
+}
+/// `AbstractBoat.push`: another boat is pushed while it is lower than this
+/// boat's top, anything else while its feet are no higher than the boat's.
+pub(super) fn boat_pushes(boat: Aabb, other: Aabb, other_is_boat: bool) -> bool {
+    if other_is_boat {
+        other.min_position().y < boat.max_position().y
+    } else {
+        other.min_position().y <= boat.min_position().y
+    }
+}
+
+impl Game<'_> {
+    /// The players in boat `id`: the window's player (or the server player
+    /// acting as it) and the server's other players.
+    pub(super) fn boat_players(&self, id: u32) -> usize {
+        let guests = self.lan.as_ref().map_or(0, |h| {
+            h.hub
+                .guests
+                .iter()
+                .filter(|g| Some(g.conn) != self.lan_acting && g.vehicle == Some(id))
+                .count()
+        });
+        usize::from(self.riding == Some(id)) + guests
+    }
+    /// The mobs in boat `id`, in their seat order after the players
+    /// (`Entity.addPassenger` puts a player first).
+    pub(super) fn boat_mobs(&self, id: u32) -> Vec<usize> {
+        (0..self.mobs.len())
+            .filter(|&j| {
+                let m = &self.mobs[j];
+                m.extra.mount == Some(id) && !m.removed && m.alive()
+            })
+            .collect()
+    }
+    /// `getPassengers().size()` of boat `id`.
+    pub(super) fn boat_passengers(&self, id: u32) -> usize {
+        self.boat_players(id) + self.boat_mobs(id).len()
+    }
+    /// `AbstractBoat.canAddPassenger`: a seat is free and the boat is not
+    /// under water.
+    pub(super) fn boat_has_room(&self, i: usize) -> bool {
+        let b = &self.boats[i];
+        self.boat_passengers(b.id) < b.max_passengers() && !b.under_water()
+    }
+    /// Where the player in boat `i` sits: in the middle alone, in front of a
+    /// mob.
+    pub(super) fn player_boat_seat(&self, i: usize) -> Vec3 {
+        let b = &self.boats[i];
+        let count = self.boat_players(b.id).max(1) + self.boat_mobs(b.id).len();
+        b.seat(0, count, false, PLAYER_RIDING_OFFSET, false)
+    }
+    /// `getRootVehicle` of mob `j`: the mob or boat at the bottom of what it
+    /// rides, None when it rides nothing.
+    fn mob_root_vehicle(&self, mut j: usize) -> Option<u32> {
+        let mut root = None;
+        for _ in 0..8 {
+            let Some(v) = self.mobs[j].extra.mount else {
+                break;
+            };
+            root = Some(v);
+            match self.mobs.iter().position(|m| m.id == v) {
+                Some(k) => j = k,
+                None => break,
+            }
+        }
+        root
+    }
+    /// The players outside boat `id` that push and block it (living, not
+    /// spectators), with the window player's team.
+    fn players_outside(&self, id: u32) -> Vec<(Aabb, bool)> {
+        let mut out = Vec::new();
+        if let Some(p) = self.player.as_ref()
+            && self.riding != Some(id)
+            && !self.spectator()
+            && !p.health.dead_or_dying()
+        {
+            out.push((p.bounds(), true));
+        }
+        if let Some(host) = self.lan.as_ref() {
+            for g in host.hub.guests.iter().filter(|g| {
+                Some(g.conn) != self.lan_acting
+                    && host.hub.here(g)
+                    && g.loaded
+                    && !g.dead
+                    && !g.spectator()
+                    && g.vehicle != Some(id)
+            }) {
+                out.push((guest_bounds(g), false));
+            }
+        }
+        out
+    }
+    /// `getEntityCollisions` of boat `id` within `area`, with
+    /// `AbstractBoat.canVehicleCollide`: the other boats, minecarts,
+    /// shulkers and pushable mobs and players, but not its own passengers.
+    pub(super) fn boat_obstacles(&self, id: u32, area: Aabb) -> Vec<Aabb> {
+        let mut out: Vec<Aabb> = (0..self.mobs.len())
+            .filter(|&j| {
+                let m = &self.mobs[j];
+                pushable(m)
+                    && m.bounds().intersects(area)
+                    && (m.extra.mount.is_none() || self.mob_root_vehicle(j) != Some(id))
+            })
+            .map(|j| self.mobs[j].bounds())
+            .collect();
+        out.extend(
+            self.boats
+                .iter()
+                .filter(|b| b.id != id)
+                .map(Boat::bounds)
+                .chain(self.carts.iter().map(|c| c.bounds()))
+                .chain(self.players_outside(id).into_iter().map(|(bb, _)| bb))
+                .filter(|bb| bb.intersects(area)),
+        );
+        out
+    }
+    /// What boat `b` may run into this tick.
+    pub(super) fn boat_move_obstacles(&self, b: &Boat) -> Vec<Aabb> {
+        let reach = b.velocity.length() + 1.0;
+        self.boat_obstacles(b.id, b.bounds().inflate(Vec3::new(reach, reach, reach)))
+    }
+    /// `noEntityCollision(boat, box)` for a new boat (`BoatItem.use`).
+    pub(super) fn boat_entity_collision(&self, bb: Aabb) -> bool {
+        // EntityGetter.getEntityCollisions: the box grown by 1e-7.
+        let area = bb.inflate(Vec3::new(1.0e-7, 1.0e-7, 1.0e-7));
+        !self.boat_obstacles(u32::MAX, area).is_empty()
+    }
+
+    /// The end of `AbstractBoat.tick` on the server for boat `i`: each
+    /// entity it touches gets in (a mob, while no player steers) or is
+    /// pushed apart from it, and `LivingEntity.pushEntities` of each mob and
+    /// player touching it pushes the two apart once more. Only the window's
+    /// own player is moved here: a server's players are pushed by their
+    /// clients, which tick the boats near them (`remote_pushes`).
+    pub(super) fn boat_contacts(&mut self, i: usize) {
+        let (id, bb, max) = {
+            let b = &self.boats[i];
+            (b.id, b.bounds(), b.max_passengers())
+        };
+        let area = bb.inflate(Vec3::new(
+            f64::from(0.2_f32),
+            f64::from(-0.01_f32),
+            f64::from(0.2_f32),
+        ));
+        let mut count = self.boat_passengers(id);
+        // getControllingPassenger is a player: one rides it (players sit first).
+        let pick_up = self.boat_players(id) == 0;
+        // canAddPassenger, which startRiding asks after the checks below.
+        let room = !self.boats[i].under_water();
+        // (mob, touched by the boat's sweep, its own pushEntities reaches the boat)
+        let teams = self.mob_teams();
+        let mobs: Vec<(usize, bool, bool)> = (0..self.mobs.len())
+            .filter_map(|j| {
+                let m = &self.mobs[j];
+                if !pushable(m) || m.extra.mount.is_some() && self.mob_root_vehicle(j) == Some(id) {
+                    return None;
+                }
+                let mb = m.bounds();
+                let team = teams.of(Who::Mob(m.id));
+                let touched = mb.intersects(area) && pushable_by(None, team, true);
+                // Bats push nothing (Bat.pushEntities).
+                let pushes = m.species() != Species::Bat
+                    && mb.intersects(bb)
+                    && pushable_by(team, None, true);
+                (touched || pushes).then_some((j, touched, pushes))
+            })
+            .collect();
+        let player_team = teams.of(Who::Player);
+        let players: Vec<(Aabb, bool, bool, bool)> = self
+            .players_outside(id)
+            .into_iter()
+            .map(|(pb, own)| {
+                let team = if own { player_team } else { None };
+                (
+                    pb,
+                    own,
+                    pb.intersects(area) && pushable_by(None, team, true),
+                    pb.intersects(bb) && pushable_by(team, None, true),
+                )
+            })
+            .collect();
+        drop(teams);
+        for (j, touched, pushes) in mobs {
+            if touched {
+                let m = &self.mobs[j];
+                let boards = pick_up
+                    && count < max
+                    && m.extra.mount.is_none()
+                    && m.width() < super::boats::WIDTH as f32
+                    && !self
+                        .res
+                        .mob_data()
+                        .entity_has("minecraft:cannot_be_pushed_onto_boats", &m.kind.id);
+                if boards {
+                    // startRiding fails quietly (no push) while the mob's
+                    // boarding cooldown runs (Entity.canRide) or the boat
+                    // is under water.
+                    if room && m.extra.boarding_cooldown <= 0 {
+                        let m = &mut self.mobs[j];
+                        m.extra.mount = Some(id);
+                        m.extra.passenger = true;
+                        m.ai.nav.stop();
+                        let mob = m.id;
+                        count += 1;
+                        // Mob.startRiding drops its lead.
+                        self.break_leash(mob, true, false);
+                    }
+                    continue;
+                }
+                self.boat_push_mob(i, j, count);
+            }
+            if pushes {
+                self.boat_push_mob(i, j, count);
+            }
+        }
+        for (pb, own, touched, pushes) in players {
+            let Some(v) = push_impulse(self.boats[i].position, pb.center())
+                .filter(|_| boat_pushes(bb, pb, false))
+            else {
+                continue;
+            };
+            for _ in 0..usize::from(touched) + usize::from(pushes) {
+                if count == 0 {
+                    let b = &mut self.boats[i];
+                    b.velocity = b.velocity.subtract(v);
+                }
+                if own && let Some(p) = self.player.as_mut() {
+                    p.velocity = p.velocity.add_vector(v);
+                }
+            }
+        }
+        for k in 0..self.boats.len() {
+            let ob = self.boats[k].bounds();
+            if k == i || !ob.intersects(area) || !boat_pushes(bb, ob, true) {
+                continue;
+            }
+            let Some(v) = push_impulse(self.boats[i].position, self.boats[k].position) else {
+                continue;
+            };
+            if count == 0 {
+                self.boats[i].velocity = self.boats[i].velocity.subtract(v);
+            }
+            if self.boat_passengers(self.boats[k].id) == 0 {
+                self.boats[k].velocity = self.boats[k].velocity.add_vector(v);
+            }
+        }
+        let guest_carts = self.guest_vehicles();
+        for c in 0..self.carts.len() {
+            let cb = self.carts[c].bounds();
+            if !cb.intersects(area) || !boat_pushes(bb, cb, false) {
+                continue;
+            }
+            let Some(v) = push_impulse(self.boats[i].position, self.carts[c].position) else {
+                continue;
+            };
+            if count == 0 {
+                self.boats[i].velocity = self.boats[i].velocity.subtract(v);
+            }
+            let cid = self.carts[c].id;
+            let ridden = self.riding == Some(cid)
+                || guest_carts.contains(&cid)
+                || self.mobs.iter().any(|m| m.extra.mount == Some(cid));
+            if !ridden {
+                self.carts[c].velocity = self.carts[c].velocity.add_vector(v);
+            }
+        }
+    }
+    /// `AbstractBoat.push(mob)` from boat `i`, which has `count` passengers.
+    fn boat_push_mob(&mut self, i: usize, j: usize, count: usize) {
+        let (b, m) = (&self.boats[i], &self.mobs[j]);
+        if !boat_pushes(b.bounds(), m.bounds(), false) {
+            return;
+        }
+        let Some(v) = push_impulse(b.position, m.position) else {
+            return;
+        };
+        if count == 0 {
+            let b = &mut self.boats[i];
+            b.velocity = b.velocity.subtract(v);
+        }
+        let m = &mut self.mobs[j];
+        if moved_by_push(m) {
+            m.velocity = m.velocity.add_vector(v);
+            m.needs_sync = true;
+        }
+    }
+
+    /// `positionRider` and `clampRotation` for the mobs in boats: each sits
+    /// in its seat facing the way the boat does, an animal in a full boat
+    /// sideways, its head kept within its reach of its body.
+    pub(super) fn seat_boat_mobs(&mut self) {
+        for i in 0..self.boats.len() {
+            let id = self.boats[i].id;
+            let mobs = self.boat_mobs(id);
+            if mobs.is_empty() {
+                continue;
+            }
+            let players = self.boat_players(id);
+            let count = players + mobs.len();
+            let b = &self.boats[i];
+            let full = count == b.max_passengers();
+            let delta = b.delta_rotation;
+            let seats: Vec<_> = mobs
+                .iter()
+                .enumerate()
+                .map(|(n, &j)| {
+                    let m = &self.mobs[j];
+                    let animal = is_animal(m.species());
+                    // Another player, on a server's client.
+                    let offset = if &*m.kind.id == "minecraft:player" {
+                        PLAYER_RIDING_OFFSET
+                    } else {
+                        riders::vehicle_attachment(m)
+                    };
+                    let index = players + n;
+                    // calculatePassengerBodyYRot.
+                    let turn = match (animal && full, m.id.is_multiple_of(2)) {
+                        (false, _) => 0.0,
+                        (true, true) => 90.0,
+                        (true, false) => 270.0,
+                    };
+                    let turns = !self
+                        .res
+                        .mob_data()
+                        .entity_has("minecraft:can_turn_in_boats", &m.kind.id);
+                    (
+                        j,
+                        b.seat(index, count, animal, offset, false),
+                        b.seat(index, count, animal, offset, true),
+                        turns.then_some((b.yaw + turn, b.previous_yaw + turn)),
+                    )
+                })
+                .collect();
+            for (j, at, previous, facing) in seats {
+                let m = &mut self.mobs[j];
+                m.position = at;
+                m.previous = previous;
+                m.velocity = Vec3::ZERO;
+                m.fall_distance = 0.0;
+                m.on_ground = false;
+                m.extra.passenger = true;
+                m.ai.nav.stop();
+                let Some((body, previous_body)) = facing else {
+                    continue;
+                };
+                m.head_yaw += delta;
+                m.body_yaw = body;
+                m.previous_body_yaw = previous_body;
+                m.yaw = body;
+                m.previous_yaw = previous_body;
+                // Mob.clampHeadRotationToBody.
+                let limit = m.kind.max_head_y_rot;
+                let d = wrap_degrees(body - m.head_yaw);
+                m.head_yaw += d - d.clamp(-limit, limit);
+            }
+        }
+    }
+    /// `ejectPassengers` for the mobs in boat `i`: each gets out where
+    /// `getDismountLocationForPassenger` puts it (beside the boat when it
+    /// broke: `LivingEntity.dismountVehicle`) and can't board for a while.
+    pub(super) fn eject_boat_mobs(&mut self, i: usize, broken: bool) {
+        let b = &self.boats[i];
+        let (id, y) = (b.id, b.position.y);
+        for j in self.boat_mobs(id) {
+            let m = &self.mobs[j];
+            let at = if broken {
+                Vec3::new(m.position.x, m.position.y.max(y), m.position.z)
+            } else {
+                self.boat_dismount_target(i, f64::from(m.width()), m.yaw)
+            };
+            let m = &mut self.mobs[j];
+            m.extra.mount = None;
+            m.extra.passenger = false;
+            m.extra.boarding_cooldown = BOARDING_COOLDOWN;
+            m.position = at;
+            m.previous = at;
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn push_is_capped_and_scaled() {
+        // One block apart on x: the full 0.05 along x.
+        let v = push_impulse(Vec3::ZERO, Vec3::new(1.0, 0.0, 0.0)).unwrap();
+        assert!((v.x - f64::from(0.05_f32)).abs() < 1e-12 && v.z == 0.0);
+        // Almost on the same spot: no push.
+        assert!(push_impulse(Vec3::ZERO, Vec3::new(0.005, 0.0, 0.0)).is_none());
+    }
+
+    #[test]
+    fn boats_push_by_height() {
+        let boat = Aabb::new(Vec3::new(0.0, 64.0, 0.0), Vec3::new(1.0, 64.5625, 1.0));
+        let at = |y: f64| Aabb::new(Vec3::new(0.0, y, 0.0), Vec3::new(1.0, y + 1.0, 1.0));
+        assert!(boat_pushes(boat, at(64.0), false));
+        assert!(!boat_pushes(boat, at(64.1), false));
+        assert!(boat_pushes(boat, at(64.5), true));
+        assert!(!boat_pushes(boat, at(64.5625), true));
+    }
+}

crates/horizon-client/src/game/boats.rs

@@ -5,10 +5,10 @@
 use super::{Game, Keys, entity_culling::at, view_vector};
 use horizon_client::{
     blocks::Fluid,
-    collisions::SceneCollisions,
+    collisions::{EntityCollisions, SceneCollisions},
     items::ItemStack,
     mesher::Vertex,
-    mobs::{Part, anim::Poses},
+    mobs::{Part, anim::Poses, riders},
 };
 use horizon_core::{
     geometry::{Aabb, Vec3},
@@ -54,10 +54,8 @@ pub(super) struct Boat {
 }
 /// `ChestBoat.CONTAINER_SIZE`.
 pub(super) const CHEST_SLOTS: usize = 27;
-const WIDTH: f64 = 1.375;
+pub(super) const WIDTH: f64 = 1.375;
 const HEIGHT: f64 = 0.5625;
-/// Player.DEFAULT_VEHICLE_ATTACHMENT minus the boat's passenger attachment.
-pub(super) const SEAT: f64 = 0.1875 - 0.6;
 impl Boat {
     pub fn new(id: u32, wood: Arc<str>, position: Vec3, yaw: f32) -> Self {
         Self {
@@ -98,6 +96,54 @@ impl Boat {
             Vec3::new(p.x + w, p.y + HEIGHT, p.z + w),
         )
     }
+    /// `isUnderWater`; it stands in for `canAddPassenger`'s
+    /// `isEyeInFluid(WATER)` too.
+    pub fn under_water(&self) -> bool {
+        matches!(self.status, Status::UnderWater | Status::UnderFlowingWater)
+    }
+    /// `getMaxPassengers`: two, one beside a chest.
+    pub fn max_passengers(&self) -> usize {
+        if self.chest { 1 } else { 2 }
+    }
+    /// `rideHeight`: a third of a boat's height, 8/9 of a raft's.
+    fn ride_height(&self) -> f64 {
+        let height = HEIGHT as f32;
+        f64::from(if &*self.wood == "bamboo" {
+            height * 0.888_888_9
+        } else {
+            height / 3.0
+        })
+    }
+    /// Where the passenger at `index` of `count` stands, at the boat's current
+    /// (or, with `previous`, last) place: `getPassengerAttachmentPoint`
+    /// turned with the boat, less the passenger's `rider_offset`.
+    pub fn seat(
+        &self,
+        index: usize,
+        count: usize,
+        animal: bool,
+        rider_offset: f64,
+        previous: bool,
+    ) -> Vec3 {
+        let mut z = if self.chest { 0.15f32 } else { 0.0 };
+        if count > 1 {
+            z = if index == 0 { 0.2 } else { -0.6 };
+            if animal {
+                z += 0.2;
+            }
+        }
+        let (at, yaw) = if previous {
+            (self.previous, self.previous_yaw)
+        } else {
+            (self.position, self.yaw)
+        };
+        riders::seat(
+            [0.0, self.ride_height(), f64::from(z)],
+            rider_offset,
+            at,
+            yaw,
+        )
+    }
     /// `getRowingTime`.
     pub fn rowing_time(&self, side: usize, a: f32) -> f32 {
         if self.paddling[side] {
@@ -183,13 +229,18 @@ impl BoatModels {
 }
 impl Game<'_> {
     fn fluid_height(&self, x: i32, y: i32, z: i32) -> Option<(f32, bool)> {
+        self.fluid_height_of(x, y, z, Some(Fluid::Water))
+    }
+    /// `FluidState.getHeight` and whether it is a source, for `fluid` or,
+    /// with `None`, any fluid (`ClipContext.Fluid.ANY`).
+    fn fluid_height_of(&self, x: i32, y: i32, z: i32, fluid: Option<Fluid>) -> Option<(f32, bool)> {
         let f = self.res.facts().get(self.world.block(x, y, z));
-        if f.fluid != Fluid::Water {
+        if f.fluid == Fluid::None || fluid.is_some_and(|want| f.fluid != want) {
             return None;
         }
         let above = self.res.facts().get(self.world.block(x, y + 1, z));
         // FluidState.getHeight: 1 under the same fluid, else amount / 9.
-        let height = if above.fluid == Fluid::Water {
+        let height = if above.fluid == f.fluid {
             1.0
         } else {
             f32::from(f.fluid_level) / 9.0
@@ -315,6 +366,7 @@ impl Game<'_> {
         let mut vspeed = -0.04;
         let mut buoyancy = 0.0;
         let inv_friction: f32;
+        let obstacles = self.boat_move_obstacles(&b);
         let mut scene = SceneCollisions {
             world: &self.world,
             binding: self.collision,
@@ -396,6 +448,11 @@ impl Game<'_> {
             b.paddling = [right && !left || up, left && !right || up];
         }
         // Entity.move: collisions zero the blocked components.
+        let mut scene = EntityCollisions {
+            blocks: scene,
+            entities: &obstacles,
+            border: None,
+        };
         if let Ok(moved) = scene.resolve(b.bounds(), b.velocity, 0.0, b.on_ground) {
             b.position = Vec3::new(
                 b.position.x + moved.x,
@@ -461,6 +518,72 @@ impl Game<'_> {
             let b = self.boats[i].clone();
             self.boats[i] = self.tick_boat(b, false);
         }
+        // AbstractBoat.tick's applyEffectsFromBlocks, on the server for every
+        // boat, the client-driven ones too.
+        let mut i = 0;
+        while i < self.boats.len() {
+            let p = self.boats[i].position;
+            let skip = Some(self.boats[i].id) == self.riding
+                || !ticking(p.x.floor() as i32, p.z.floor() as i32);
+            if skip || !self.boat_lava_tick(i) {
+                i += 1;
+            }
+        }
+        // The rest of AbstractBoat.tick on the server, for every boat: the
+        // passengers of one under water too long get out, and it picks up or
+        // pushes what it touches.
+        for i in 0..self.boats.len() {
+            let p = self.boats[i].position;
+            if !ticking(p.x.floor() as i32, p.z.floor() as i32) {
+                continue;
+            }
+            if self.boats[i].out_of_control >= 60.0 {
+                self.eject_boat_mobs(i, false);
+            }
+            self.boat_contacts(i);
+        }
+    }
+    /// `LavaFluid.entityInside` (`lavaHurt`) from the two
+    /// `applyEffectsFromBlocks` calls in `AbstractBoat.tick`: twice 40
+    /// damage, so lava breaks a boat on its first tick inside, and the fire
+    /// `lavaIgnite` lights never gets to burn it. True when the boat broke.
+    fn boat_lava_tick(&mut self, i: usize) -> bool {
+        if !self.in_lava(self.boats[i].bounds()) {
+            return false;
+        }
+        for _ in 0..2 {
+            let p = self.boats[i].position;
+            let broke = self.hurt_boat(i, 4.0, false);
+            self.lava_hurt_sound([p.x, p.y, p.z]);
+            if broke {
+                return true;
+            }
+        }
+        false
+    }
+    /// `Entity.lavaHurt`'s sound once the hurt went through.
+    pub(super) fn lava_hurt_sound(&mut self, at: [f64; 3]) {
+        let pitch = 2.0 + self.world.random.next_float() * 0.4;
+        self.audio
+            .play("minecraft:entity.generic.burn", Some(at), 0.4, pitch);
+    }
+    /// Whether a vehicle's box, deflated by 1e-5, reaches into lava below its
+    /// surface (`Entity.collidedWithFluid`).
+    pub(super) fn in_lava(&self, bb: Aabb) -> bool {
+        let (lo, hi) = (bb.min_position(), bb.max_position());
+        let e = 1.0e-5;
+        for x in (lo.x + e).floor() as i32..=(hi.x - e).floor() as i32 {
+            for y in (lo.y + e).floor() as i32..=(hi.y - e).floor() as i32 {
+                for z in (lo.z + e).floor() as i32..=(hi.z - e).floor() as i32 {
+                    if let Some((height, _)) = self.fluid_height_of(x, y, z, Some(Fluid::Lava))
+                        && lo.y + e < f64::from(y) + f64::from(height)
+                    {
+                        return true;
+                    }
+                }
+            }
+        }
+        false
     }
     /// The player's tick while riding: steer, tick the boat, sit in it.
     pub(super) fn tick_riding(&mut self, keys: Keys) -> horizon_client::Result<()> {
@@ -482,22 +605,35 @@ impl Game<'_> {
         self.yaw += b.delta_rotation;
         let delta = (self.yaw - b.yaw + 180.0).rem_euclid(360.0) - 180.0;
         self.yaw += delta.clamp(-105.0, 105.0) - delta;
+        self.boats[i] = b;
+        let seat = self.player_boat_seat(i);
         if let Some(p) = self.player.as_mut() {
             self.previous_position = p.position;
-            p.position = Vec3::new(b.position.x, b.position.y + SEAT, b.position.z);
+            p.position = seat;
             p.velocity = Vec3::ZERO;
             p.fall_distance = 0.0;
         }
-        self.boats[i] = b;
+        if self.boat_lava_tick(i) {
+            self.riding = None;
+        }
         Ok(())
     }
     /// `getDismountLocationForPassenger`: in front of the player if there is
     /// floor there, else on top of the boat.
     pub(super) fn dismount(&mut self, i: usize) {
         self.riding = None;
+        let target = self.boat_dismount_target(i, 0.6, self.yaw);
+        if let Some(p) = self.player.as_mut() {
+            p.position = target;
+            p.velocity = Vec3::ZERO;
+        }
+    }
+    /// `getDismountLocationForPassenger` for a passenger `width` wide
+    /// facing `yaw`.
+    pub(super) fn boat_dismount_target(&self, i: usize, width: f64, yaw: f32) -> Vec3 {
         let b = &self.boats[i];
-        let r = self.yaw.to_radians();
-        let distance = (WIDTH * std::f64::consts::SQRT_2 + 0.6 + 1.0e-5) / 2.0;
+        let r = yaw.to_radians();
+        let distance = (WIDTH * std::f64::consts::SQRT_2 + width + 1.0e-5) / 2.0;
         let (s, c) = (-(r.sin()) as f64, r.cos() as f64);
         let m = s.abs().max(c.abs());
         let (x, z) = (
@@ -508,17 +644,13 @@ impl Game<'_> {
         let (bx, by, bz) = (x.floor() as i32, top.floor() as i32, z.floor() as i32);
         let below = self.res.facts().get(self.world.block(bx, by - 1, bz));
         let here = self.res.facts().get(self.world.block(bx, by, bz));
-        let target = if below.fluid != Fluid::Water
+        if below.fluid != Fluid::Water
             && !here.full_collision
             && (below.full_collision || below.legacy_solid)
         {
             Vec3::new(x, f64::from(by), z)
         } else {
             Vec3::new(b.position.x, top, b.position.z)
-        };
-        if let Some(p) = self.player.as_mut() {
-            p.position = target;
-            p.velocity = Vec3::ZERO;
         }
     }
     /// `BoatItem.use`: aim at a block or the water surface.
@@ -534,7 +666,8 @@ impl Game<'_> {
         };
         let dir = view_vector(self.yaw, self.pitch);
         let reach = self.reach();
-        // ClipContext.Fluid.ANY: the first water surface or block along the ray.
+        // ClipContext.Fluid.ANY: the first fluid surface (water or lava) or
+        // block along the ray.
         let block = self.pick().map(|h| {
             (
                 h.point,
@@ -544,7 +677,7 @@ impl Game<'_> {
                     .sqrt(),
             )
         });
-        let mut water = None;
+        let mut fluid = None;
         let mut t = 0.0;
         while t < reach {
             let p: [f64; 3] = std::array::from_fn(|a| eye[a] + dir[a] * t);
@@ -553,15 +686,15 @@ impl Game<'_> {
                 p[1].floor() as i32,
                 p[2].floor() as i32,
             );
-            if let Some((h, _)) = self.fluid_height(x, y, z)
+            if let Some((h, _)) = self.fluid_height_of(x, y, z, None)
                 && p[1] <= f64::from(y) + f64::from(h)
             {
-                water = Some(([p[0], f64::from(y) + f64::from(h), p[2]], t));
+                fluid = Some(([p[0], f64::from(y) + f64::from(h), p[2]], t));
                 break;
             }
             t += 0.05;
         }
-        let hit = match (block, water) {
+        let hit = match (block, fluid) {
             (Some(b), Some(w)) => {
                 if w.1 < b.1 {
                     w.0
@@ -594,7 +727,7 @@ impl Game<'_> {
             binding: self.collision,
             subject: None,
         };
-        if !scene.unobstructed(inner).unwrap_or(false) {
+        if !scene.unobstructed(inner).unwrap_or(false) || self.boat_entity_collision(bb) {
             return false;
         }
         self.next_entity += 1;
@@ -649,7 +782,7 @@ impl Game<'_> {
             return false;
         }
         // ChestBoat.interact: sneaking (or a full seat) opens the chest.
-        if self.boats[i].chest && (sneaking || self.riding.is_some()) {
+        if self.boats[i].chest && (sneaking || self.riding.is_some() || !self.boat_has_room(i)) {
             let b = &self.boats[i];
             let key = (i32::MAX - 15, super::minecarts::CART_KEY_Y, b.id as i32);
             self.world.block_entities.insert(
@@ -666,6 +799,7 @@ impl Game<'_> {
             || self.boats[i].out_of_control >= 60.0
             || self.riding.is_some()
             || self.ridden_by_guest(self.boats[i].id)
+            || !self.boat_has_room(i)
         {
             return false;
         }
@@ -682,15 +816,24 @@ impl Game<'_> {
             return false;
         }
         self.vehicle_attack_sounds();
+        self.hurt_boat(i, damage, self.creative);
+        self.swing_arm();
+        true
+    }
+    /// `VehicleEntity.hurtServer`: wobble, add the damage and break past 40
+    /// (`creative`: a creative player's hit removes it without drops).
+    /// True when the boat was removed.
+    pub(super) fn hurt_boat(&mut self, i: usize, damage: f32, creative: bool) -> bool {
         let b = &mut self.boats[i];
         b.hurt_dir = -b.hurt_dir;
         b.hurt_time = 10;
         b.damage += damage * 10.0;
-        let destroyed = self.creative || b.damage > 40.0;
+        let destroyed = creative || b.damage > 40.0;
         if destroyed {
+            self.eject_boat_mobs(i, true);
             let b = self.boats.remove(i);
             let at = [b.position.x, b.position.y, b.position.z];
-            if !self.creative && self.ui.rules.bool("entity_drops") {
+            if !creative && self.ui.rules.bool("entity_drops") {
                 // ChestBoat.destroy: chestVehicleDestroyed spills the contents.
                 for stack in b.items.iter().flatten() {
                     self.spawn_item(stack.clone(), at, super::dispenser::new_item_motion(), 10);
@@ -709,8 +852,7 @@ impl Game<'_> {
                 );
             }
         }
-        self.swing_arm();
-        true
+        destroyed
     }
     /// AbstractBoatRenderer.
     pub(super) fn boat_geometry(&self, camera: glam::DVec3, alpha: f64, out: &mut Vec<Vertex>) {

crates/horizon-client/src/game/bossbars.rs

@@ -1,22 +1,29 @@
 //! `/bossbar` (BossBarCommands) and drawing the custom boss bars.
 use super::{
-    Game,
-    commands::{R, err},
+    Dim, Game,
+    commands::{R, Target, err},
 };
 use horizon_client::{
+    boss_overlay,
     bossbar::{self, BossBars},
     command::{Arg, Context},
-    hud_overlays, save,
-    scoreboard::{self as sb, Comp, comp_text},
+    mobs::Species,
+    save,
+    scoreboard::{self as sb, Comp, json_to_tag},
     scoreboard_cmd::format_list,
     text::Text,
 };
+use horizon_core::random::RandomSource;
+use horizon_protocol::packets::play::{self, BossAction, Clientbound as C};
 use horizon_world::nbt::Tag;
+use std::collections::{HashMap, HashSet};
 
 #[derive(Default)]
 pub(super) struct BossState {
     pub bars: BossBars,
     loaded: bool,
+    /// What each viewer was last sent, so a change becomes one packet.
+    sent: HashMap<u128, HashMap<u128, Offer>>,
 }
 
 fn num(n: impl std::fmt::Display) -> Text {
@@ -36,7 +43,7 @@ impl Game<'_> {
         if let Some(root) = save::read_dat(&self.bossbar_path())
             && let Some(data) = root.get("data")
         {
-            self.bosses.bars = BossBars::unpack(data, self.level.player_uuid);
+            self.bosses.bars = BossBars::unpack(data);
         }
         self.ui.registries.bossbars = self.bosses.bars.ids();
     }
@@ -47,13 +54,15 @@ impl Game<'_> {
         if self.bosses.bars.bars.is_empty() && !self.bossbar_path().exists() {
             return;
         }
-        let _ = save::write_dat(
+        if let Err(e) = save::write_dat(
             &self.bossbar_path(),
             Tag::compound([
-                ("data", self.bosses.bars.pack(self.level.player_uuid)),
+                ("data", self.bosses.bars.pack()),
                 ("DataVersion", Tag::Int(horizon_world::DATA_VERSION)),
             ]),
-        );
+        ) {
+            log::warn!("boss bars were not written: {e}");
+        }
     }
     pub(in crate::game) fn bossbar_exists(&self, id: &str) -> bool {
         self.bosses.bars.get(id).is_some()
@@ -68,6 +77,7 @@ impl Game<'_> {
                 b.value = b.value.min(b.max);
             }
         }
+        self.publish_boss_bars();
     }
     fn bar_id(ctx: &Context) -> String {
         match ctx.get("id") {
@@ -86,6 +96,7 @@ impl Game<'_> {
         self.load_bossbars();
         let result = self.bossbar_command(id, ctx);
         self.ui.registries.bossbars = self.bosses.bars.ids();
+        self.publish_boss_bars();
         result
     }
     fn bossbar_command(&mut self, id: &str, ctx: &Context) -> R<i32> {
@@ -97,6 +108,10 @@ impl Game<'_> {
                 }
                 let name = self.component_json(ctx, "name")?;
                 self.bosses.bars.add(&bar, name);
+                if let Some(b) = self.bosses.bars.get_mut(&bar) {
+                    // CustomBossEvents.create: Mth.createInsecureUUID(level.random).
+                    b.uuid = insecure_uuid(&mut self.world.random);
+                }
                 let shown = self
                     .bosses
                     .bars
@@ -173,19 +188,20 @@ impl Game<'_> {
                         i32::from(b.visible)
                     }
                     _ => {
-                        if b.player {
-                            let name = self.target_name(super::commands::Target::Player);
-                            self.feedback(Text::translate(
-                                "commands.bossbar.get.players.some",
-                                &[s, num(1), format_list(vec![name])],
-                            ));
-                        } else {
+                        let names = self.bossbar_player_names(&b.players);
+                        let n = names.len();
+                        if n == 0 {
                             self.feedback(Text::translate(
                                 "commands.bossbar.get.players.none",
                                 &[s],
                             ));
+                        } else {
+                            self.feedback(Text::translate(
+                                "commands.bossbar.get.players.some",
+                                &[s, num(n), format_list(names)],
+                            ));
                         }
-                        i32::from(b.player)
+                        n as i32
                     }
                 })
             }
@@ -295,31 +311,46 @@ impl Game<'_> {
                 Ok(0)
             }
             _ => {
-                // players [<targets>]
-                let include = if ctx.get("targets").is_some() {
-                    !self.entities(ctx, "targets", true)?.is_empty()
+                // players [<targets>]: replace the set. No argument clears it.
+                let targets = if ctx.get("targets").is_some() {
+                    self.entities(ctx, "targets", true)?
                 } else {
-                    false
+                    Vec::new()
                 };
+                let mut uuids = Vec::new();
+                let mut names = Vec::new();
+                for t in &targets {
+                    let Some(uuid) = self.player_target_uuid(*t) else {
+                        continue;
+                    };
+                    if !uuids.contains(&uuid) {
+                        uuids.push(uuid);
+                        names.push(self.target_name(*t));
+                    }
+                }
                 let b = self.bosses.bars.get_mut(bar).expect("checked");
-                if b.player == include {
+                let mut had = b.players.clone();
+                had.sort();
+                let mut next = uuids.clone();
+                next.sort();
+                if had == next {
                     return Err(err("commands.bossbar.set.players.unchanged", &[]));
                 }
-                b.player = include;
+                b.players = uuids;
+                let n = b.players.len();
                 let s = shown(self);
-                if include {
-                    let name = self.target_name(super::commands::Target::Player);
-                    self.feedback(Text::translate(
-                        "commands.bossbar.set.players.success.some",
-                        &[s, num(1), format_list(vec![name])],
-                    ));
-                } else {
+                if n == 0 {
                     self.feedback(Text::translate(
                         "commands.bossbar.set.players.success.none",
                         &[s],
                     ));
+                } else {
+                    self.feedback(Text::translate(
+                        "commands.bossbar.set.players.success.some",
+                        &[s, num(targets.len()), format_list(names)],
+                    ));
                 }
-                Ok(i32::from(include))
+                Ok(n as i32)
             }
         }
     }
@@ -333,29 +364,316 @@ impl Game<'_> {
         Ok(self.resolve_component(value))
     }
 
-    // ---- drawing ------------------------------------------------------------------
-
-    /// The visible custom bars (`/bossbar`), after the built-in ones.
-    pub(super) fn custom_bossbars(&self, bars: &mut Vec<hud_overlays::BossBar>) {
-        for b in self
-            .bosses
-            .bars
-            .bars
-            .iter()
-            .filter(|b| b.visible && b.player)
-        {
-            bars.push(hud_overlays::BossBar {
-                name: comp_text(&b.name),
-                progress: b.progress(),
-                color: bossbar::COLORS
+    /// Names of the online players in a boss bar's set, in join order.
+    fn bossbar_player_names(&self, players: &[[i32; 4]]) -> Vec<Text> {
+        self.known_boss_players()
+            .into_iter()
+            .filter(|(uuid, _)| players.contains(uuid))
+            .map(|(_, name)| name)
+            .collect()
+    }
+    /// The players who can be told about a bar: the one in place, then guests.
+    fn known_boss_players(&self) -> Vec<([i32; 4], Text)> {
+        let mut out = Vec::new();
+        if self.player.is_some() {
+            out.push((self.acting_uuid(), self.target_name(Target::Player)));
+        }
+        if let Some(host) = &self.lan {
+            for g in host.hub.guests.iter().filter(|g| g.placed) {
+                let ints = horizon_client::lan::playerdata::uuid_ints(g.uuid);
+                if out.iter().any(|(uuid, _)| *uuid == ints) {
+                    continue;
+                }
+                out.push((ints, Text::literal(g.name.clone())));
+            }
+        }
+        out
+    }
+    fn player_target_uuid(&self, target: Target) -> Option<[i32; 4]> {
+        match target {
+            Target::Player => Some(self.acting_uuid()),
+            Target::Guest(conn) => self.lan.as_ref().and_then(|h| {
+                h.hub
+                    .guests
                     .iter()
-                    .position(|c| *c == b.color)
-                    .unwrap_or(0),
-                overlay: bossbar::STYLES
-                    .iter()
-                    .position(|s| *s == b.style)
-                    .unwrap_or(0),
-            });
+                    .find(|g| g.conn == conn)
+                    .map(|g| horizon_client::lan::playerdata::uuid_ints(g.uuid))
+            }),
+            _ => None,
         }
     }
+
+    // ---- ServerBossEvent delivery ------------------------------------------------
+
+    /// Tell every viewer the boss events they should be seeing. The window
+    /// that simulates the world applies them to its own overlay; everyone
+    /// else gets `ClientboundBossEventPacket`s.
+    pub(super) fn publish_boss_bars(&mut self) {
+        if self.remote.is_some() {
+            return;
+        }
+        self.load_bossbars();
+        let now = boss_overlay::now_millis();
+        let viewers = self.boss_viewers();
+        let live: HashSet<u128> = viewers.iter().map(|v| v.uuid).collect();
+        self.bosses.sent.retain(|id, _| live.contains(id));
+        let mut packets = Vec::new();
+        for viewer in &viewers {
+            let desired = self.boss_events_for(viewer);
+            for event in self.diff_boss_events(viewer, desired) {
+                if viewer.local {
+                    self.boss_overlay.apply(&event, now);
+                } else if let Some(conn) = viewer.conn {
+                    packets.push((conn, C::BossEvent(event)));
+                }
+            }
+        }
+        if packets.is_empty() {
+            return;
+        }
+        let Some(host) = self.lan.as_ref() else {
+            return;
+        };
+        for (conn, packet) in &packets {
+            host.hub.send_to(*conn, packet);
+        }
+    }
+    fn boss_viewers(&self) -> Vec<Viewer> {
+        let mut out = Vec::new();
+        // While `as_guest` has swapped a guest in, the host's own position
+        // is not in place. Their overlay updates once the tick puts it back.
+        let local =
+            self.serving.is_none() && self.options.dedicated.is_none() && self.lan_acting.is_none();
+        if local && let Some(p) = &self.player {
+            let ints = self.level.player_uuid.unwrap_or_else(|| self.acting_uuid());
+            out.push(Viewer {
+                uuid: horizon_client::lan::playerdata::ints_uuid(ints),
+                ints,
+                at: [p.position.x, p.position.y, p.position.z],
+                alive: !p.health.dead_or_dying(),
+                here: true,
+                local: true,
+                conn: None,
+                view_chunks: self.settings.render_distance,
+            });
+        }
+        if let Some(host) = &self.lan {
+            for g in host.hub.guests.iter().filter(|g| g.placed) {
+                if out.iter().any(|v| v.uuid == g.uuid) {
+                    continue;
+                }
+                out.push(Viewer {
+                    uuid: g.uuid,
+                    ints: horizon_client::lan::playerdata::uuid_ints(g.uuid),
+                    at: g.position,
+                    alive: !g.dead,
+                    here: g.dimension == self.dim.id(),
+                    local: false,
+                    conn: Some(g.conn),
+                    view_chunks: g.view_distance,
+                });
+            }
+        }
+        out
+    }
+    /// Custom bars (`CustomBossEvents.onPlayerConnect` sends them as a player
+    /// joins), then the dragon, withers and the raid.
+    fn boss_events_for(&self, viewer: &Viewer) -> Vec<Offer> {
+        let mut out = Vec::new();
+        for b in &self.bosses.bars.bars {
+            if !b.visible || !b.players.contains(&viewer.ints) {
+                continue;
+            }
+            out.push(Offer {
+                id: b.uuid,
+                name: json_to_tag(&b.name),
+                progress: b.progress(),
+                color: color_index(&b.color),
+                overlay: style_index(&b.style),
+                darken: b.darken,
+                music: b.music,
+                fog: b.fog,
+                scope: Scope::Global,
+            });
+        }
+        if viewer.here
+            && let Some(progress) = self.dragon_boss_progress(viewer.at, viewer.alive)
+        {
+            out.push(Offer {
+                id: bossbar::stable_uuid("minecraft:ender_dragon"),
+                name: translate_tag("entity.minecraft.ender_dragon"),
+                progress,
+                color: 0,
+                overlay: 0,
+                darken: false,
+                music: true,
+                fog: true,
+                scope: Scope::Level(self.dim),
+            });
+        }
+        if viewer.here {
+            let range = f64::from(10.min(viewer.view_chunks.max(0)) * 16);
+            for m in self
+                .mobs
+                .iter()
+                .filter(|m| m.species() == Species::Wither && m.alive() && !m.removed)
+            {
+                let (dx, dz) = (m.position.x - viewer.at[0], m.position.z - viewer.at[2]);
+                if dx * dx + dz * dz > range * range {
+                    continue;
+                }
+                let progress = if m.extra.counter > 0 {
+                    1.0 - m.extra.counter as f32 / horizon_client::mobs::wither::INVULNERABLE as f32
+                } else {
+                    (m.health / m.attrs.max_health).clamp(0.0, 1.0)
+                };
+                let name = if let Some(text) = &m.custom_name_text {
+                    json_to_tag(&text.component())
+                } else if let Some(name) = &m.custom_name {
+                    Tag::String(name.as_str().into())
+                } else {
+                    translate_tag("entity.minecraft.wither")
+                };
+                out.push(Offer {
+                    id: super::lan::entity_uuid(m.id),
+                    name,
+                    progress,
+                    color: 5,
+                    overlay: 0,
+                    darken: true,
+                    music: false,
+                    fog: false,
+                    scope: Scope::Level(self.dim),
+                });
+            }
+        }
+        if viewer.here
+            && let Some((id, name, progress)) = self.raid_boss_at(viewer.at, viewer.alive)
+        {
+            out.push(Offer {
+                id: bossbar::stable_uuid(&format!("raid:{id}")),
+                name,
+                progress,
+                color: 2,
+                overlay: 2,
+                darken: false,
+                music: false,
+                fog: false,
+                scope: Scope::Level(self.dim),
+            });
+        }
+        out
+    }
+    /// The packets that take `viewer` from what it was last sent to `desired`
+    /// (`ServerBossEvent`'s broadcasts).
+    fn diff_boss_events(&mut self, viewer: &Viewer, desired: Vec<Offer>) -> Vec<play::BossEvent> {
+        let full = viewer.local;
+        let dim = self.dim;
+        let sent = self.bosses.sent.entry(viewer.uuid).or_default();
+        let mut out = Vec::new();
+        let event = |id, action| play::BossEvent { id, action };
+        sent.retain(|id, prev| {
+            let owned = full || prev.scope == Scope::Global || prev.scope == Scope::Level(dim);
+            let keep = !owned || desired.iter().any(|e| e.id == *id);
+            if !keep {
+                out.push(event(*id, BossAction::Remove));
+            }
+            keep
+        });
+        for offer in desired {
+            let Some(prev) = sent.get(&offer.id) else {
+                out.push(event(
+                    offer.id,
+                    BossAction::Add {
+                        name: offer.name.clone(),
+                        progress: offer.progress,
+                        color: offer.color,
+                        overlay: offer.overlay,
+                        darken: offer.darken,
+                        music: offer.music,
+                        fog: offer.fog,
+                    },
+                ));
+                sent.insert(offer.id, offer);
+                continue;
+            };
+            let id = offer.id;
+            if prev.progress != offer.progress {
+                let progress = offer.progress;
+                out.push(event(id, BossAction::UpdateProgress { progress }));
+            }
+            if prev.name != offer.name {
+                let name = offer.name.clone();
+                out.push(event(id, BossAction::UpdateName { name }));
+            }
+            if (prev.color, prev.overlay) != (offer.color, offer.overlay) {
+                let (color, overlay) = (offer.color, offer.overlay);
+                out.push(event(id, BossAction::UpdateStyle { color, overlay }));
+            }
+            if (prev.darken, prev.music, prev.fog) != (offer.darken, offer.music, offer.fog) {
+                let (darken, music, fog) = (offer.darken, offer.music, offer.fog);
+                out.push(event(
+                    id,
+                    BossAction::UpdateProperties { darken, music, fog },
+                ));
+            }
+            sent.insert(id, offer);
+        }
+        out
+    }
+    /// `ClientPacketListener.handleBossUpdate`.
+    pub(super) fn apply_boss_event(&mut self, packet: &play::BossEvent) {
+        self.boss_overlay.apply(packet, boss_overlay::now_millis());
+    }
+}
+
+/// `Mth.createInsecureUUID`.
+fn insecure_uuid(random: &mut impl RandomSource) -> u128 {
+    let most = random.next_long() & -61441 | 16384;
+    let least = random.next_long() & 4_611_686_018_427_387_903 | i64::MIN;
+    ((most as u64 as u128) << 64) | (least as u64 as u128)
+}
+fn translate_tag(key: &str) -> Tag {
+    Tag::compound([("translate", Tag::String(key.into()))])
+}
+fn color_index(color: &str) -> i32 {
+    bossbar::COLORS
+        .iter()
+        .position(|c| *c == color)
+        .unwrap_or(6) as i32
+}
+fn style_index(style: &str) -> i32 {
+    bossbar::STYLES
+        .iter()
+        .position(|s| *s == style)
+        .unwrap_or(0) as i32
+}
+
+#[derive(Clone, Copy, PartialEq, Eq)]
+enum Scope {
+    Global,
+    Level(Dim),
+}
+struct Viewer {
+    uuid: u128,
+    ints: [i32; 4],
+    at: [f64; 3],
+    alive: bool,
+    here: bool,
+    local: bool,
+    conn: Option<u32>,
+    view_chunks: i32,
+}
+/// A boss event as one viewer should see it, and as it was last sent.
+struct Offer {
+    id: u128,
+    name: Tag,
+    progress: f32,
+    /// `BossBarColor` and `BossBarOverlay` ordinals.
+    color: i32,
+    overlay: i32,
+    darken: bool,
+    music: bool,
+    fog: bool,
+    scope: Scope,
 }

crates/horizon-client/src/game/chat.rs

@@ -1,6 +1,6 @@
 //! Chat, the command registries and the per-world state behind commands
 //! (game rules, the world clock, difficulty), bound to the game.
-use super::{Dim, Game, Screen};
+use super::{Game, Screen};
 use horizon_client::{
     chat::{Chat, ChatAction, ChatScreen, Commands, SYSTEM_INDICATOR},
     command::Registries,
@@ -570,8 +570,14 @@ impl Game<'_> {
     /// ChatScreen.handleChatInput: history, then a command or a chat line.
     pub(super) fn handle_chat_input(&mut self, message: &str) {
         self.ui.chat.add_recent(message);
-        // On a server (single player's own included) the server runs it.
+        // On a server (single player's own included) the server runs it,
+        // unless a client mod owns the command.
         if self.remote.is_some() {
+            if let Some(command) = message.strip_prefix('/')
+                && self.mod_command(command)
+            {
+                return;
+            }
             self.send_chat(message);
             return;
         }
@@ -695,10 +701,7 @@ impl Game<'_> {
     /// Advance the overworld clock (ServerClockManager.tick) when
     /// `advance_time` allows it.
     pub(super) fn advance_clock(&mut self) {
-        if !self.ui.rules.bool("advance_time")
-            || self.ui.clock.paused
-            || self.dim == Dim::Nether && false
-        {
+        if !self.ui.rules.bool("advance_time") || self.ui.clock.paused {
             return;
         }
         let c = &mut self.ui.clock;
@@ -819,8 +822,12 @@ impl Game<'_> {
             ("data", data),
             ("DataVersion", Tag::Int(horizon_world::DATA_VERSION)),
         ]);
-        let _ = horizon_client::save::write_dat(&path, root);
-        let _ = write_difficulty(&self.world_root, self.ui.difficulty);
+        if let Err(e) = horizon_client::save::write_dat(&path, root) {
+            log::warn!("the world clocks were not written: {e}");
+        }
+        if let Err(e) = write_difficulty(&self.world_root, self.ui.difficulty) {
+            log::warn!("the difficulty was not written: {e}");
+        }
     }
     /// Death message in chat (CombatTracker.getDeathMessage, as far as the
     /// cause is known to the client).

crates/horizon-client/src/game/commands.rs

@@ -42,7 +42,8 @@ pub(super) enum Target {
     Mob(u32),
     Item(u32),
     Orb(usize),
-    Arrow(usize),
+    /// By index in `creatures.projectiles`.
+    Projectile(usize),
     Stand(u32),
     Frame(u32),
     Painting(u32),
@@ -327,7 +328,7 @@ impl Game<'_> {
                 .orbs
                 .get(i)
                 .map(|o| [o.position.x, o.position.y, o.position.z]),
-            Target::Arrow(i) => self
+            Target::Projectile(i) => self
                 .creatures
                 .projectiles
                 .get(i)
@@ -382,7 +383,11 @@ impl Game<'_> {
                 }),
             Target::Item(_) => "minecraft:item".into(),
             Target::Orb(_) => "minecraft:experience_orb".into(),
-            Target::Arrow(_) => "minecraft:arrow".into(),
+            Target::Projectile(i) => self
+                .creatures
+                .projectiles
+                .get(i)
+                .map_or_else(String::new, |p| p.kind.id().into()),
             Target::Stand(_) => "minecraft:armor_stand".into(),
             Target::Frame(id) => {
                 if self.item_frames.iter().any(|f| f.id == id && f.glow) {
@@ -503,6 +508,7 @@ impl Game<'_> {
             _ => {}
         }
         if s.kind != 's' {
+            use horizon_client::projectiles::ProjectileKind as K;
             candidates.extend(self.player_candidates(s));
             candidates.extend(
                 self.mobs
@@ -517,8 +523,12 @@ impl Game<'_> {
                     .projectiles
                     .iter()
                     .enumerate()
-                    .filter(|(_, p)| p.arrow.is_some())
-                    .map(|(i, _)| Target::Arrow(i)),
+                    // The kinds /data can write (entity_nbt).
+                    .filter(|(_, p)| {
+                        p.arrow.is_some()
+                            || matches!(p.kind, K::LargeFireball { .. } | K::SmallFireball)
+                    })
+                    .map(|(i, _)| Target::Projectile(i)),
             );
             candidates.extend(self.armor_stands.iter().map(|a| Target::Stand(a.id)));
             candidates.extend(self.item_frames.iter().map(|f| Target::Frame(f.id)));
@@ -1082,6 +1092,8 @@ impl Game<'_> {
                 self.for_player(t, |g| g.teleport_to(Target::Player, pos, rotation));
             }
             Target::Player => {
+                // ServerPlayer.teleport: removeVehicle before placing the player.
+                self.stop_riding();
                 if let Some(p) = self.player.as_mut() {
                     p.position = v;
                     p.velocity = Vec3::new(0.0, 0.0, 0.0);
@@ -1098,9 +1110,15 @@ impl Game<'_> {
                 if let Some(m) = self.mobs.iter_mut().find(|m| m.id == id) {
                     m.position = v;
                     m.previous = v;
-                    if let Some([yaw, _]) = rotation {
+                    // Entity.teleportSetPosition: setYRot, setYHeadRot, setXRot
+                    // (clamped to -90..90), then setOldRot.
+                    if let Some([yaw, pitch]) = rotation {
                         m.yaw = yaw;
                         m.body_yaw = yaw;
+                        m.head_yaw = yaw;
+                        m.head_pitch = pitch.clamp(-90.0, 90.0);
+                        m.previous_yaw = m.yaw;
+                        m.previous_head_pitch = m.head_pitch;
                     }
                 }
             }
@@ -1116,7 +1134,7 @@ impl Game<'_> {
                     o.previous = v;
                 }
             }
-            Target::Arrow(i) => {
+            Target::Projectile(i) => {
                 if let Some(a) = self.creatures.projectiles.get_mut(i) {
                     a.position = v;
                     a.previous = v;
@@ -1540,14 +1558,10 @@ impl Game<'_> {
                     self.orbs[i].age = u32::MAX / 2;
                 }
             }
-            Target::Arrow(i) => {
-                if let Some(a) = self
-                    .creatures
-                    .projectiles
-                    .get_mut(i)
-                    .and_then(|p| p.arrow.as_mut())
-                {
-                    a.removed = true;
+            // cmd_kill goes from the highest index down.
+            Target::Projectile(i) => {
+                if i < self.creatures.projectiles.len() {
+                    self.creatures.projectiles.remove(i);
                 }
             }
             Target::Stand(id) => self.armor_stands.retain(|a| a.id != id),
@@ -1569,7 +1583,7 @@ impl Game<'_> {
         let mut ordered = targets.clone();
         ordered.sort_by_key(|t| {
             std::cmp::Reverse(match t {
-                Target::Orb(i) | Target::Arrow(i) => *i,
+                Target::Orb(i) | Target::Projectile(i) => *i,
                 _ => 0,
             })
         });
@@ -1577,9 +1591,6 @@ impl Game<'_> {
             self.kill_target(t);
         }
         self.orbs.retain(|o| o.age < u32::MAX / 2);
-        self.creatures
-            .projectiles
-            .retain(|p| !p.arrow.as_ref().is_some_and(|a| a.removed));
         let message = if targets.len() == 1 {
             Text::translate("commands.kill.success.single", &[names[0].clone()])
         } else {
@@ -1783,8 +1794,11 @@ impl Game<'_> {
             self.level_set(pos, state)
                 .map_err(|e| CommandError::new(Text::literal(e.to_string())))?;
         }
+        // LevelChunk.setBlockState creates it when the block, not the state, is still
+        // there after onPlace: a powered hopper turns itself `enabled=false`.
+        let landed = self.world.block(pos[0], pos[1], pos[2]);
         if old != new
-            && self.world.block(pos[0], pos[1], pos[2]) == state
+            && self.res.facts().get(landed).name == new
             && let Some(entity) = horizon_client::containers::BlockEntity::for_block(&new)
         {
             self.world.block_entities.insert(key, entity);

crates/horizon-client/src/game/commands/data.rs

@@ -65,9 +65,10 @@ impl Game<'_> {
                 tag
             }
             Target::Mob(id) => {
-                let uuid = self.uuid_for(id);
-                let m = self.mobs.iter().find(|m| m.id == id)?;
-                entity_nbt::mob_to_nbt(m, uuid, self.persist.raw.get(&id))
+                // `saveWithoutId` writes the entity as saved, riders under
+                // `Passengers`: `/data get` reads the same tree persistence does (#1519).
+                let i = self.mobs.iter().position(|m| m.id == id)?;
+                self.mob_tree_nbt(i)
             }
             Target::Item(id) => {
                 let uuid = self.uuid_for(id);
@@ -113,7 +114,7 @@ impl Game<'_> {
                 self.other_to_nbt(&o, uuid)
             }
             Target::Orb(i) => entity_nbt::orb_to_nbt(self.orbs.get(i)?, random_uuid()),
-            Target::Arrow(i) => {
+            Target::Projectile(i) => {
                 let p = self.creatures.projectiles.get(i)?;
                 let owner = if p.owner == Some(horizon_client::mobs::Who::Player) {
                     player_uuid
@@ -125,7 +126,8 @@ impl Game<'_> {
                     .as_ref()
                     .and_then(|a| a.last_state)
                     .map(|s| self.state_to_nbt(s));
-                entity_nbt::arrow_to_nbt(p, random_uuid(), owner, in_block, None)?
+                entity_nbt::arrow_to_nbt(p, random_uuid(), owner, in_block, None)
+                    .or_else(|| entity_nbt::fireball_to_nbt(p, random_uuid(), owner, None))?
             }
         })
     }

crates/horizon-client/src/game/commands/world_cmds.rs

@@ -59,7 +59,15 @@ impl Game<'_> {
                 self.recipe_unlocked(&unlocked);
                 count as i32
             } else {
-                self.level.recipe_book.remove_recipes(index, &recipes) as i32
+                let removed = self.level.recipe_book.remove_recipes(index, &recipes);
+                let count = removed.len() as i32;
+                // A network player's client drops them from its book.
+                if self.lan_acting.is_some() && !removed.is_empty() {
+                    self.guest_packets.push(C::RecipeBookRemove(
+                        horizon_protocol::packets::recipes::RecipeBookRemove { ids: removed },
+                    ));
+                }
+                count
             };
             tracker.track(&h, n);
         }
@@ -345,7 +353,26 @@ impl Game<'_> {
             Some(Arg::Resource(s)) => Some(s.clone()),
             _ => None,
         };
-        self.audio.stop_sounds(sound.as_deref(), source);
+        // StopSoundCommand: each target's connection gets the packet; the
+        // window's own player stops its sounds.
+        let packet = C::StopSound(play::StopSound {
+            source: source.map(|s| s as i32),
+            sound: sound.clone(),
+        });
+        for &t in &targets {
+            match t {
+                Target::Player if self.lan_acting.is_some() => {
+                    self.guest_packets.push(packet.clone());
+                }
+                Target::Player => self.audio.stop_sounds(sound.as_deref(), source),
+                Target::Guest(conn) => {
+                    if let Some(host) = self.lan.as_ref() {
+                        host.hub.send_to(conn, &packet);
+                    }
+                }
+                _ => {}
+            }
+        }
         let key = match (source, &sound) {
             (Some(_), Some(_)) => "commands.stopsound.success.source.sound",
             (Some(_), None) => "commands.stopsound.success.source.any",

crates/horizon-client/src/game/consume.rs

@@ -128,7 +128,7 @@ impl Game<'_> {
         if self.state_in_tag(avoid, ground) {
             return false;
         }
-        let entities = self.happy_ghast_player_collisions();
+        let entities = self.player_entity_collisions();
         let Some(player) = self.player.as_mut() else {
             return false;
         };

crates/horizon-client/src/game/control.rs

@@ -226,6 +226,16 @@ impl Game<'_> {
                 }
                 Ok(Some(json!({ "ok": true, "cull": r.section_cull() })))
             }
+            "section-sides" => {
+                let r = self.renderer.as_mut().ok_or("no renderer")?;
+                match words.get(1).copied() {
+                    None => {}
+                    Some("on") => r.set_section_sides(true),
+                    Some("off") => r.set_section_sides(false),
+                    Some(other) => return Err(format!("unknown section sides mode {other}").into()),
+                }
+                Ok(Some(json!({ "ok": true, "sides": r.section_sides() })))
+            }
             "sculk" => Ok(Some(self.sculk_command(&words)?)),
             "status" => Ok(Some(self.control_status())),
             "pad" => Ok(Some(self.pad_command(&words)?)),
@@ -503,7 +513,10 @@ impl Game<'_> {
                 if self.pending_screenshot.is_some() {
                     return Err("a screenshot is already pending".into());
                 }
-                renderer.screenshot = Some(arg(1)?.into());
+                arg(1)?;
+                // The rest of the line: a path may hold spaces.
+                let path = line.trim_start().strip_prefix("screenshot").unwrap_or("");
+                renderer.screenshot = Some(path.trim().into());
                 self.pending_screenshot = Some(reply.clone());
                 Ok(None)
             }
@@ -589,7 +602,6 @@ impl Game<'_> {
                     "credits" => Page::Credits,
                     "horizon" => Page::Horizon,
                     "agent" => Page::Agent,
-                    "shader-packs" => Page::ShaderPacks,
                     other => return Err(format!("unknown options page {other}").into()),
                 };
                 if self.screen == Screen::Playing && self.title.is_none() {
@@ -982,6 +994,7 @@ impl Game<'_> {
         status["destroying"] = json!(destroying);
         status["physical_keys"] = json!(physical_keys);
         status["heard"] = json!(self.audio.heard);
+        status["stopped_sounds"] = json!(self.audio.stopped);
         // Boats, minecarts, armor stands, item frames and paintings.
         status["objects"] = json!(self.objects_status());
         status["lightning"] = json!({"bolts": self.bolts.len(), "struck": self.lightning_seen[0],

crates/horizon-client/src/game/creatures.rs

@@ -978,7 +978,9 @@ impl Game<'_> {
                         m.ai.target = Some(target);
                     }
                 }
-                MobEvent::Projectile(p) => {
+                MobEvent::Projectile(mut p) => {
+                    self.next_entity += 1;
+                    p.id = self.next_entity;
                     let (owner, at) = (p.owner, [p.position.x, p.position.y, p.position.z]);
                     self.creatures.projectiles.push(p);
                     self.projectile_event("minecraft:projectile_shoot", owner, at);
@@ -1496,12 +1498,16 @@ impl Game<'_> {
                 o.hurt
             }
         {
-            let (xd, zd) = (from[0] - player.position.x, from[2] - player.position.z);
-            self.knock_back_player(f64::from(0.4_f32), xd, zd);
-            if let Some(p) = self.player.as_mut()
-                && let Some(r) = p.hurt_log.last_mut()
-            {
-                r.knockback = Some([p.velocity.x, p.velocity.y, p.velocity.z]);
+            // LivingEntity.hurtServer's dealDefaultKnockback: not inside the
+            // hurt cooldown (a stronger hit there only adds its difference).
+            if o.knockback {
+                let (xd, zd) = (from[0] - player.position.x, from[2] - player.position.z);
+                self.knock_back_player(f64::from(0.4_f32), xd, zd);
+                if let Some(p) = self.player.as_mut()
+                    && let Some(r) = p.hurt_log.last_mut()
+                {
+                    r.knockback = Some([p.velocity.x, p.velocity.y, p.velocity.z]);
+                }
             }
             self.hurt_armor(amount);
             self.thorns(from);

crates/horizon-client/src/game/debug_keys.rs

@@ -38,7 +38,7 @@ impl DebugHost for Host<'_, '_> {
         // the menu as it always has (key_pressed).
         let g = &mut *self.game;
         if without_menu && g.screen == Screen::Playing {
-            g.pause_menu = !(g.has_singleplayer_server() && !g.is_published());
+            g.pause_menu = !g.has_singleplayer_server() || g.is_published();
             g.screen = Screen::Paused;
             g.capture(false);
             g.mining = None;
@@ -82,8 +82,10 @@ impl Game<'_> {
             }
             return true;
         }
-        // Screens with a text box take every key press first
-        // (EditBox.keyPressed); releases still reach KeyboardHandler.
+        // Vanilla types into a focused EditBox through charTyped, which no
+        // debug key can swallow. Here the character comes with the key press,
+        // so a screen with a focused text box takes every press first;
+        // releases still reach KeyboardHandler.
         let typing = matches!(
             self.screen,
             Screen::Chat | Screen::Options | Screen::WorldOptions | Screen::CommandBlock
@@ -91,7 +93,11 @@ impl Game<'_> {
             || self.book.is_some()
             || (self.screen == Screen::Creative && self.creative_screen.tab().search)
             || self.recipe_search_focused()
-            || self.station_typing();
+            || self.station_typing()
+            || self
+                .title
+                .as_mut()
+                .is_some_and(|t| t.focused_field().is_some());
         // Container screens use Escape, the inventory key and the hotbar and
         // drop keys first; any other screen closes on Escape.
         let screen_key = match self.screen {
@@ -179,7 +185,9 @@ impl Game<'_> {
                 // Minecraft.emergencySaveAndCrash: the world is saved, then the
                 // game stops; main writes the crash report.
                 let crash = horizon_client::crash::DebugCrash::new();
-                let _ = self.save_game();
+                if let Err(e) = self.save_game() {
+                    log::error!("the emergency save before the crash failed: {e}");
+                }
                 return Err(crash.into());
             }
         }
@@ -593,7 +601,6 @@ impl Game<'_> {
             DebugAction::ReloadResourcePacks => {
                 self.debug_translated("debug.reload_resourcepacks.message");
                 self.reload_packs();
-                self.load_shader_pack();
                 true
             }
             DebugAction::CopyLocation if player => {

crates/horizon-client/src/game/dedicated.rs

@@ -6,7 +6,7 @@
 //! its simulation and the play-state hub that LAN hosting uses, configured
 //! from server.properties, with the operator, whitelist and ban lists and a
 //! console on standard input.
-use super::{Game, Options, lan::LanSettings};
+use super::{Game, Options, lan::LanSettings, world_loading::WorldRequest};
 use horizon_client::{
     Result,
     lan::{LoginGate, NetConfig, NetLog, OnlineMode, hub::HubConfig},
@@ -218,21 +218,22 @@ impl Lists {
             use_whitelist: false,
             enforce_whitelist: false,
         };
+        // DedicatedPlayerList's constructor order and its LOGGER.warn lines.
         let warn = |what: &str, r: std::result::Result<(), String>| {
             if let Err(e) = r {
-                log("WARN", &format!("Failed to load {what}: {e}"));
+                log("WARN", &format!("Failed to {what}: {e}"));
             }
         };
-        // DedicatedPlayerList's constructor order.
-        warn("user banlist", l.bans.load());
-        let _ = l.bans.save();
-        warn("ip banlist", l.ip_bans.load());
-        let _ = l.ip_bans.save();
-        warn("operators list", l.ops.load());
-        warn("white-list", l.white.load());
-        let _ = l.ops.save();
+        let saved = |r: std::io::Result<()>| r.map_err(|e| e.to_string());
+        warn("load user banlist", l.bans.load());
+        warn("save user banlist", saved(l.bans.save()));
+        warn("load ip banlist", l.ip_bans.load());
+        warn("save ip banlist", saved(l.ip_bans.save()));
+        warn("load operators list", l.ops.load());
+        warn("load white-list", l.white.load());
+        warn("save operators list", saved(l.ops.save()));
         if !l.white.file.exists() {
-            let _ = l.white.save();
+            warn("save white-list", saved(l.white.save()));
         }
         l
     }
@@ -546,13 +547,13 @@ impl Game<'_> {
         let lists = Arc::new(Mutex::new(lists));
         log("INFO", &format!("Preparing level \"{level_name}\""));
         let folder = world_dir.to_string_lossy().into_owned();
-        self.open_world(
+        self.load_world(WorldRequest::new(
             &folder,
             Some(&level_name),
             Some(props.seed),
             game_mode == 1,
             None,
-        )?;
+        )?)?;
         if new_world {
             self.level.hardcore = props.hardcore;
         }
@@ -608,6 +609,7 @@ impl Game<'_> {
                 lang: Arc::new(horizon_client::net::load_language(&self.options.resources)),
                 log_ips: props.log_ips,
             }),
+            resource_pack: props.resource_pack.clone(),
         };
         let config = HubConfig {
             default_game_mode: game_mode,

crates/horizon-client/src/game/discord.rs

@@ -0,0 +1,43 @@
+//! What the player is doing, for Discord Rich Presence (`horizon_client::discord_presence`).
+use super::*;
+use horizon_client::discord_presence::{self as presence, Dimension, Play, Status};
+
+impl Game<'_> {
+    /// Each frame: only a change reaches the presence thread.
+    pub(super) fn update_discord_presence(&self) {
+        presence::set(self.discord_status());
+    }
+    fn discord_status(&self) -> Status {
+        if !self.settings.extras.discord_presence {
+            return Status::Off;
+        }
+        if self.title.is_some() {
+            return Status::Menus;
+        }
+        let play = if let Some(host) = &self.lan {
+            Play::Hosting {
+                players: 1 + host.hub.guests.len(),
+            }
+        } else if let Some(server) = &self.integrated {
+            match (server.published(), &self.remote) {
+                (Some(_), Some(remote)) => Play::Hosting {
+                    players: remote.player_count(),
+                },
+                _ => Play::Singleplayer,
+            }
+        } else if self.remote.is_some() {
+            Play::Multiplayer
+        } else {
+            Play::Singleplayer
+        };
+        Status::World {
+            play,
+            dimension: match self.dim {
+                Dim::Overworld => Dimension::Overworld,
+                Dim::Nether => Dimension::Nether,
+                Dim::End => Dimension::End,
+            },
+            mode: self.mode,
+        }
+    }
+}

crates/horizon-client/src/game/dragon.rs

@@ -12,7 +12,6 @@ use horizon_client::{
     hud_layout, hud_overlays,
     mesher::Vertex,
     particles::{ParticleOptions, ParticleType},
-    text::Text,
 };
 use horizon_core::{
     geometry::{Aabb, Vec3},
@@ -2157,23 +2156,12 @@ impl Game<'_> {
             });
         }
     }
-    /// `BossHealthOverlay`: the dragon's pink bar, then the withers', the
-    /// raids' and the custom bars, in that order.
+    /// `BossHealthOverlay.extractRenderState`: whatever `publish_boss_bars`
+    /// (or a server's packets) put on this client's overlay.
     pub(super) fn draw_boss_bars(&self, batch: &mut HudBatch) {
-        let mut bars = Vec::new();
-        if let Some(d) = self.dragon.as_ref().filter(|_| self.dragon_bar_shown()) {
-            bars.push(hud_overlays::BossBar {
-                name: Text::literal(
-                    self.translate("entity.minecraft.ender_dragon", "Ender Dragon"),
-                ),
-                progress: (d.health / MAX_HEALTH).clamp(0.0, 1.0),
-                color: 0,
-                overlay: 0,
-            });
-        }
-        self.wither_bars(&mut bars);
-        self.raid_bars(&mut bars);
-        self.custom_bossbars(&mut bars);
+        let bars = self
+            .boss_overlay
+            .bars(horizon_client::boss_overlay::now_millis());
         let draws = hud_overlays::boss_overlay(
             batch.width as i32,
             batch.height as i32,
@@ -2182,14 +2170,26 @@ impl Game<'_> {
         );
         hud_layout::paint(batch, &self.gui.atlas, &draws);
     }
-    /// The dragon fight's boss bar shows (`EnderDragonFight.dragonEvent`,
-    /// with `setCreateWorldFog`).
-    pub(super) fn dragon_bar_shown(&self) -> bool {
-        self.dim == Dim::End && self.dragon.is_some()
+    /// The dragon fight's bar for a player at `at`
+    /// (`EnderDragonFight.dragonEvent`, visible while the fight is not won
+    /// and the player is alive within 192 blocks of (0, 128, 0)).
+    pub(super) fn dragon_boss_progress(&self, at: [f64; 3], alive: bool) -> Option<f32> {
+        if self.dim != Dim::End || !alive || !self.fight.loaded || self.fight.killed {
+            return None;
+        }
+        let near = at[0].powi(2) + (at[1] - 128.0).powi(2) + at[2].powi(2) <= 192.0 * 192.0;
+        if !near {
+            return None;
+        }
+        Some(
+            self.dragon
+                .as_ref()
+                .map_or(1.0, |d| (d.health / MAX_HEALTH).clamp(0.0, 1.0)),
+        )
     }
-    /// `music.dragon` while the boss bar plays music.
+    /// `BossHealthOverlay.shouldPlayMusic`.
     pub(super) fn boss_music(&self) -> bool {
-        self.dim == Dim::End && self.dragon.is_some() || self.wither_near()
+        self.boss_overlay.should_play_music()
     }
 }
 pub(super) struct DragonFireball {

crates/horizon-client/src/game/execution_role.rs

@@ -0,0 +1,39 @@
+//! A Game's execution role is fixed at construction. Connecting or disconnecting
+//! changes `remote`, not this role. A client may simulate a world in-frame.
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub(super) enum ExecutionRole {
+    Client,
+    IntegratedServer,
+    DedicatedServer,
+}
+
+impl ExecutionRole {
+    /// Only a client owns presentation work (audio, loading UI, chunk meshes).
+    pub fn is_client(self) -> bool {
+        self == Self::Client
+    }
+
+    /// The optional in-frame simulation remains a client execution mode.
+    pub fn starts_integrated_server(self, server_thread: bool) -> bool {
+        self.is_client() && server_thread
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::ExecutionRole::*;
+
+    #[test]
+    fn world_loading_keeps_in_frame_clients_and_server_roles_separate() {
+        for (role, client, threaded) in [
+            (Client, true, true),
+            (IntegratedServer, false, false),
+            (DedicatedServer, false, false),
+        ] {
+            assert_eq!(role.is_client(), client);
+            assert_eq!(role.starts_integrated_server(true), threaded);
+            assert!(!role.starts_integrated_server(false));
+        }
+    }
+}

crates/horizon-client/src/game/fov.rs

@@ -74,7 +74,7 @@ impl Game<'_> {
         })
     }
     /// The fluid at the camera, as `Camera.getFluidInCamera` reports it.
-    fn camera_fluid(&self, camera: [f64; 3]) -> CameraFluid {
+    pub(super) fn camera_fluid(&self, camera: [f64; 3]) -> CameraFluid {
         match fog_type(&self.world, self.res.facts(), camera, self.forward()) {
             FogType::Water => CameraFluid::Water,
             FogType::Lava => CameraFluid::Lava,

crates/horizon-client/src/game/friends.rs

@@ -200,7 +200,7 @@ impl Game<'_> {
             }
             Action::Copy => self.friends_copy(),
             Action::Stop => self.friends_stop(),
-            // The system browser, as the Shader Packs page opens its folder.
+            // The system browser, as the folder buttons open their folders.
             Action::Help => {
                 if let Some(url) = &view.help {
                     super::packs::open_folder(std::path::Path::new(url));

crates/horizon-client/src/game/game_rules_screen.rs

@@ -3,6 +3,7 @@
 //! box each, and Done sending the changed ones (ServerboundSetGameRulePacket).
 //! Leaving with changes asks first (ConfirmScreen).
 use horizon_client::{
+    confirm_screen::Confirm,
     font::Font,
     gamerules::{self, GameRules, RULES, Rule, Value},
     hud::{HudAtlas, HudBatch},
@@ -66,9 +67,6 @@ fn parse(r: &Rule, s: &str) -> Option<i32> {
         .flatten()
         .filter(|v| (r.min..=r.max).contains(v))
 }
-fn widest(font: &Font, lines: &[Text]) -> f32 {
-    lines.iter().map(|l| font.width_text(l)).fold(0.0, f32::max)
-}
 fn lines(font: &Font, t: &Text, width: f32) -> Vec<Text> {
     font.split_lines(t, width)
         .into_iter()
@@ -95,38 +93,11 @@ fn yellow() -> u32 {
     named_color("yellow").unwrap_or(0xFFFF55)
 }
 
-/// ConfirmScreen: the title, the message (at most `width - 50` wide), and
-/// Yes / No 16 below, 4 apart, all centred.
-struct Confirm {
-    lines: Vec<(Text, f32, f32)>,
-    buttons: [(f32, f32); 2],
-}
-impl Confirm {
-    fn new(font: &Font, (w, h): (f32, f32)) -> Self {
-        let title = Text::translate("editGamerule.inGame.discardChanges.title", &[]);
-        let message = Text::translate("editGamerule.inGame.discardChanges.message", &[]);
-        let message: Vec<Text> = lines(font, &message, w - 50.0)
-            .into_iter()
-            .take(15)
-            .collect();
-        let (tw, mw) = (font.width_text(&title), widest(font, &message));
-        let mh = 9.0 * message.len() as f32;
-        let col = tw.max(mw).max(304.0);
-        let total = 9.0 + 8.0 + mh + 8.0 + 36.0;
-        let (lx, ly) = (((w - col) / 2.0).trunc(), ((h - total) / 2.0).trunc());
-        let cell = |cw: f32| lx + ((col - cw) / 2.0).trunc();
-        let mid = cell(mw) + (mw / 2.0).trunc();
-        let mut out = vec![(title, cell(tw), ly)];
-        for (i, line) in message.into_iter().enumerate() {
-            let x = mid - (font.width_text(&line) / 2.0).trunc();
-            out.push((line, x, ly + 17.0 + 9.0 * i as f32));
-        }
-        let (bx, by) = (cell(304.0), ly + 9.0 + 8.0 + mh + 8.0 + 16.0);
-        Self {
-            lines: out,
-            buttons: [(bx, by), (bx + 154.0, by)],
-        }
-    }
+/// ConfirmScreen "Game Rule Changes".
+fn confirm(font: &Font, size: (f32, f32)) -> Confirm {
+    let title = Text::translate("editGamerule.inGame.discardChanges.title", &[]);
+    let message = Text::translate("editGamerule.inGame.discardChanges.message", &[]);
+    Confirm::new(font, size, &title, &message)
 }
 
 impl RulesScreen {
@@ -301,13 +272,10 @@ impl RulesScreen {
         let (w, h) = size;
         let on = |x: f32, y: f32, bw: f32, bh: f32| ui::hovered(cursor, x, y, bw, bh);
         if self.confirm {
-            let c = Confirm::new(&atlas.font, size);
-            let [(yx, yy), (nx, ny)] = c.buttons;
-            if on(yx, yy, 150.0, 20.0) {
-                return Some(Exit::Discard);
-            }
-            if on(nx, ny, 150.0, 20.0) {
-                self.confirm = false;
+            match confirm(&atlas.font, size).answer_at(cursor) {
+                Some(true) => return Some(Exit::Discard),
+                Some(false) => self.confirm = false,
+                None => {}
             }
             return None;
         }
@@ -367,7 +335,7 @@ impl RulesScreen {
         let (w, h) = size;
         let on = |(x, y): (f32, f32)| ui::hovered(cursor, x, y, 150.0, 20.0);
         if self.confirm {
-            return Confirm::new(&atlas.font, size).buttons.into_iter().any(on);
+            return confirm(&atlas.font, size).answer_at(cursor).is_some();
         }
         let [done, cancel] = footer(w, h);
         if (on(done) && !self.invalid()) || on(cancel) {
@@ -384,15 +352,11 @@ impl RulesScreen {
         let (w, h) = (batch.width, batch.height);
         ui::menu_background(batch, atlas, 0.0, 0.0, w, h, true);
         if self.confirm {
-            let c = Confirm::new(&atlas.font, (w, h));
-            for (line, x, y) in &c.lines {
-                batch.text_styled(atlas, line, *x, *y, u32::MAX, true);
-            }
-            for ((bx, by), key) in c.buttons.into_iter().zip(["gui.yes", "gui.no"]) {
-                let hover = ui::hovered(cursor, bx, by, 150.0, 20.0);
-                let label = Text::translate(key, &[]);
-                ui::button(batch, atlas, bx, by, 150.0, 20.0, &label, true, hover);
-            }
+            let labels = [
+                Text::translate("gui.yes", &[]),
+                Text::translate("gui.no", &[]),
+            ];
+            confirm(&atlas.font, (w, h)).draw(batch, atlas, cursor, [&labels[0], &labels[1]]);
             return;
         }
         let rows = self.rows();

crates/horizon-client/src/game/ghasts.rs

@@ -10,9 +10,10 @@ use horizon_core::geometry::{Aabb, Vec3};
 use horizon_world::registry::BlockStateId;
 
 impl Game<'_> {
-    /// Client `EntityGetter.getEntityCollisions`: only solid happy ghasts,
-    /// excluding the player's own vehicle.
-    pub(super) fn happy_ghast_player_collisions(&self) -> Vec<Aabb> {
+    /// Client `EntityGetter.getEntityCollisions` for the player: the
+    /// entities that `canBeCollidedWith` it, solid happy ghasts and boats
+    /// (`AbstractBoat.canBeCollidedWith`), except the player's own vehicle.
+    pub(super) fn player_entity_collisions(&self) -> Vec<Aabb> {
         let Some(p) = &self.player else {
             return Vec::new();
         };
@@ -24,6 +25,12 @@ impl Game<'_> {
                     && happy_ghast::collides_with_player(m, p.position.y)
             })
             .map(|m| m.bounds())
+            .chain(
+                self.boats
+                    .iter()
+                    .filter(|b| Some(b.id) != self.riding)
+                    .map(super::boats::Boat::bounds),
+            )
             .collect()
     }
     /// `HappyGhast.mobInteract`. Returns whether the click was used.

crates/horizon-client/src/game/integrated.rs

@@ -12,7 +12,9 @@
 //! way.
 use super::{
     Game, Options, PackResources, Resources, UiResources,
+    execution_role::ExecutionRole,
     lan::{LanSettings, Owner},
+    world_loading::WorldRequest,
 };
 use horizon_client::{
     Result,
@@ -26,7 +28,6 @@ use horizon_protocol::connection::Pipe;
 use horizon_protocol::{crypto::offline_uuid, text::translatable};
 use std::{
     net::TcpListener,
-    path::Path,
     sync::{
         Arc, Mutex,
         atomic::{AtomicBool, AtomicI32, AtomicU16, AtomicU32, Ordering},
@@ -170,11 +171,6 @@ struct Launch {
     player: String,
 }
 
-/// Whether this world opens on a server thread: asked for.
-pub(super) fn wanted(options: &Options, _world: &Path) -> bool {
-    options.server_thread && options.dedicated.is_none()
-}
-
 impl Game<'_> {
     /// `Minecraft.hasSingleplayerServer`: a world of this window's own, run
     /// in the frame or on its server thread.
@@ -215,9 +211,10 @@ impl Game<'_> {
         };
         let mut options = self.options.clone();
         // A server without a console: no local player, no window, no control socket.
+        // Compatibility for gameplay checks outside startup/world loading.
         options.dedicated = Some(Vec::new());
         options.server_thread = false;
-        options.integrated = true;
+        options.execution_role = ExecutionRole::IntegratedServer;
         options.control = None;
         options.benchmark = None;
         options.frames = None;
@@ -287,13 +284,13 @@ impl Game<'_> {
         tasks: Receiver<Task>,
         ready: &Sender<Ready>,
     ) -> Result<()> {
-        self.open_world(
+        self.load_world(WorldRequest::new(
             &launch.folder,
             launch.name.as_deref(),
             launch.seed,
             launch.creative,
             launch.create.as_ref(),
-        )?;
+        )?)?;
         let saved = Box::new(self.level.clone());
         // Math.max(2, options.renderDistance): past vanilla's 32 when the
         // window's render distance is (Horizon's options go to 64).
@@ -496,6 +493,22 @@ impl Game<'_> {
         out
     }
 
+    /// Run `f` with the owner's level in place (the server holds one per
+    /// dimension), then put back the level that was.
+    pub(super) fn in_owner_level<T>(&mut self, f: impl FnOnce(&mut Self) -> T) -> T {
+        let owner = self.serving.as_ref().map(|s| s.owner);
+        let dim = self.lan.as_ref().and_then(|h| {
+            let g = h.hub.guests.iter().find(|g| Some(g.uuid) == owner)?;
+            Some(super::Dim::from_id(&g.dimension))
+        });
+        let back = dim.and_then(|d| self.enter_command_level(d));
+        let out = f(self);
+        if let Some(back) = back {
+            self.enter_command_level(back);
+        }
+        out
+    }
+
     /// The window's requests, between two ticks.
     fn run_tasks(&mut self) {
         let tasks: Vec<Task> = match &self.serving {

crates/horizon-client/src/game/lan.rs

@@ -834,8 +834,11 @@ impl Game<'_> {
         self.lan_object_states(host_entity, hub, out);
     }
 
-    /// Run the hub for this tick and apply what the guests did.
-    pub(super) fn tick_lan(&mut self) {
+    /// Run the hub for this tick and apply what the guests did. While the
+    /// single player game is `paused` only the connections run
+    /// (`IntegratedServer.tickPaused`): `ServerGamePacketListenerImpl.tick`
+    /// skips `tickPlayer`, so no player's air, hunger or damage moves on.
+    pub(super) fn tick_lan(&mut self, paused: bool) {
         let Some(mut host) = self.lan.take() else {
             return;
         };
@@ -1000,7 +1003,9 @@ impl Game<'_> {
             host.states = states;
         }
         self.lan_flush_effects(&mut host);
-        self.tick_guests(&mut host);
+        if !paused {
+            self.tick_guests(&mut host);
+        }
         self.lan_living_flags(&mut host);
         self.tick_server_travel(&mut host);
         self.lan_swings(&mut host);

crates/horizon-client/src/game/lan_actions.rs

@@ -1277,10 +1277,24 @@ impl Game<'_> {
         id: i32,
         location: Option<[f64; 3]>,
     ) -> Option<([f64; 3], [f64; 3])> {
+        let eye = {
+            let g = &host.hub.guests[gi];
+            [g.position[0], g.position[1] + g.eye_height(), g.position[2]]
+        };
         let object = || {
             let (lo, hi, origin) = self.object_target(id)?;
             let middle = [0, 1, 2].map(|k| (lo[k] + hi[k]) / 2.0);
             let Some(l) = location else {
+                // A boat's mobs sit over its middle: aim low at its near
+                // side, so the ray meets the boat before them (the server
+                // attacks the entity it is sent).
+                let carries = u32::try_from(id).is_ok_and(|v| {
+                    self.boats.iter().any(|b| b.id == v) && !self.boat_mobs(v).is_empty()
+                });
+                if carries {
+                    let near = |k: usize| eye[k].clamp(lo[k] + 0.01, hi[k] - 0.01);
+                    return Some([near(0), lo[1] + 0.05, near(2)]);
+                }
                 return Some(middle);
             };
             let point = [0, 1, 2].map(|k| origin[k] + l[k]);
@@ -1311,7 +1325,6 @@ impl Game<'_> {
             }
         };
         let g = &mut host.hub.guests[gi];
-        let eye = [g.position[0], g.position[1] + g.eye_height(), g.position[2]];
         let d = [centre[0] - eye[0], centre[1] - eye[1], centre[2] - eye[2]];
         let horizontal = (d[0] * d[0] + d[2] * d[2]).sqrt();
         g.yaw = (-d[0].atan2(d[2])).to_degrees() as f32;
@@ -1713,6 +1726,17 @@ impl Game<'_> {
                         g.use_delay -= 1;
                     }
                 });
+                // ServerPlayerGameMode.handleBlockBreakAction: a creative
+                // player's START breaks the block once (destroyAndAck) and
+                // leaves nothing being destroyed; its client sends no STOP.
+                // Kept, the dig broke whatever was put there next, every
+                // destroy delay, for as long as the player broke nothing else.
+                if digging.is_some()
+                    && host.hub.guests[gi].creative()
+                    && let Some(play) = host.play.get_mut(&conn)
+                {
+                    play.digging = None;
+                }
             }
             // Player.tick: a different main-hand item resets the attack
             // strength, and detectEquipmentUpdates gives the guest its modifiers.
@@ -1915,7 +1939,7 @@ impl Game<'_> {
         let in_wall = !g.sleeping && self.in_wall(g.position, g.eye_height());
         let at = g.position;
         let sneaking = g.sneaking;
-        let sounds = self.as_guest(host, conn, |game| {
+        let events = self.as_guest(host, conn, |game| {
             let (rules, motion) = (game.world.health_rules, game.motion);
             let health = &motion.health;
             let Some(player) = game.player.as_mut() else {
@@ -2012,20 +2036,17 @@ impl Game<'_> {
             // A hurt since the last tick marked the velocity (Entity.markHurt):
             // ServerEntity.sendChanges sends it as it is after this travel.
             let marked = std::mem::take(&mut player.health.sync_velocity);
-            let sounds = events
-                .into_iter()
-                .filter_map(|e| match e {
-                    MotionEvent::HurtSound(sound) => Some(sound),
-                    _ => None,
-                })
-                .collect::<Vec<_>>();
-            (sounds, marked.then_some(player.velocity))
+            (events, marked.then_some(player.velocity))
         });
-        let Some((sounds, marked)) = sounds else {
+        let Some((events, marked)) = events else {
             return;
         };
-        for sound in sounds {
-            self.player_hurt_sound(sound, at);
+        for event in events {
+            match event {
+                MotionEvent::HurtSound(sound) => self.player_hurt_sound(sound, at),
+                MotionEvent::Fall(event) => self.landing_block_updates(&event),
+                _ => {}
+            }
         }
         if let (Some(v), Some(g)) = (marked, host.hub.guest(conn)) {
             g.send(&C::SetEntityMotion(play::SetEntityMotion {
@@ -2428,6 +2449,32 @@ impl Game<'_> {
             .map_or(&[][..], |log| log.get(logged..).unwrap_or(&[]))
             .to_vec();
         let facts = self.res.facts();
+        // BlockItem.place: `playSound(player, ...)`, for the others only. The
+        // placer's client plays it as its block appears.
+        let placed: Vec<([f64; 3], String)> = changed
+            .iter()
+            .map(|&(x, y, z)| {
+                let at = [f64::from(x) + 0.5, f64::from(y) + 0.5, f64::from(z) + 0.5];
+                let name = &facts.get(self.world.block(x, y, z)).sounds.place;
+                (at, name.trim_start_matches("minecraft:").to_owned())
+            })
+            .collect();
+        if let Some(capture) = self.audio.capture.as_mut() {
+            let mut i = heard.min(capture.len());
+            while i < capture.len() {
+                let (name, at, ..) = &capture[i];
+                let place = placed
+                    .iter()
+                    .any(|(p, n)| p == at && name.trim_start_matches("minecraft:") == n.as_str());
+                if place {
+                    let (name, at, volume, pitch) = capture.remove(i);
+                    let source = horizon_client::settings::sound_source(&name) as i32;
+                    host.hub.sound(&name, at, volume, pitch, source, Some(conn));
+                } else {
+                    i += 1;
+                }
+            }
+        }
         if changed.is_empty()
             || !changed.iter().all(|&(x, y, z)| {
                 super::remote::hand_operated(&facts.get(self.world.block(x, y, z)).name)

crates/horizon-client/src/game/lan_entities.rs

@@ -321,20 +321,7 @@ impl Game<'_> {
         }
         for p in self.creatures.projectiles.iter().filter(|p| p.id != 0) {
             use horizon_client::projectiles::ProjectileKind as K;
-            let kind = match &p.kind {
-                K::Arrow { .. } => "minecraft:arrow",
-                K::Snowball => "minecraft:snowball",
-                K::Egg => "minecraft:egg",
-                K::EnderPearl => "minecraft:ender_pearl",
-                K::SmallFireball => "minecraft:small_fireball",
-                K::LargeFireball { .. } => "minecraft:fireball",
-                K::LlamaSpit => "minecraft:llama_spit",
-                K::WindCharge => "minecraft:wind_charge",
-                K::BreezeWindCharge => "minecraft:breeze_wind_charge",
-                K::ShulkerBullet { .. } => "minecraft:shulker_bullet",
-                K::WitherSkull { .. } => "minecraft:wither_skull",
-                K::Potion { .. } => "minecraft:splash_potion",
-            };
+            let kind = p.kind.id();
             let mut e = state(p.id, kind, at(p.position), p.yaw, false);
             e.pitch = p.pitch;
             e.velocity = at(p.velocity);

crates/horizon-client/src/game/lan_trading.rs

@@ -48,10 +48,9 @@ impl Game<'_> {
         if let Some(id) = state.mob
             && state.session.villager
         {
-            // startTrading with the guest's reputation (their effects are
-            // not modelled on the host: no Hero of the Village).
+            // startTrading with the guest's reputation. The session already
+            // captured their Hero effect while they acted as the player.
             state.session.reputation = self.villager_reputation_of(id, uuid);
-            state.session.hero = None;
             state.session.update_special_prices();
         }
         let title = self.merchant_display_name(&state);

crates/horizon-client/src/game/lan_vehicles.rs

@@ -9,7 +9,7 @@
 //! here with the rider's input (`ServerPlayer.getLastClientMoveIntent`).
 //! Sneaking gets out (`Player.rideTick`: `wantsToStopRiding`), and the client
 //! is teleported where the player lands (`ServerPlayer.dismountTo`).
-use super::{Game, Keys, boats::SEAT, lan::LanHost};
+use super::{Game, Keys, lan::LanHost, minecarts::SEAT};
 use horizon_client::collisions::SceneCollisions;
 use horizon_core::geometry::{Aabb, Vec3};
 use horizon_protocol::{
@@ -120,8 +120,8 @@ impl Game<'_> {
                     game.dismount(i);
                     return None;
                 }
-                let p = game.boats[i].position;
-                return Some([p.x, p.y + SEAT, p.z]);
+                let p = game.player_boat_seat(i);
+                return Some([p.x, p.y, p.z]);
             }
             // The minecart moves with the rider's input, and lets it out when
             // it sneaks or the cart breaks. An animal takes the rider's input
@@ -161,19 +161,19 @@ impl Game<'_> {
         let at = self
             .boats
             .iter()
-            .find(|b| b.id == vehicle)
-            .map(|b| b.position)
+            .position(|b| b.id == vehicle)
+            .map(|i| (self.boats[i].position, self.player_boat_seat(i)))
             .or_else(|| {
                 self.carts
                     .iter()
                     .find(|c| c.id == vehicle)
-                    .map(|c| c.position)
+                    .map(|c| (c.position, c.position.add_vector(Vec3::new(0.0, SEAT, 0.0))))
             });
-        if let Some(p) = at {
+        if let Some((p, seat)) = at {
             let g = &mut host.hub.guests[gi];
             g.vehicle_good = Some([p.x, p.y, p.z]);
             g.previous_position = g.position;
-            g.position = [p.x, p.y + SEAT, p.z];
+            g.position = [seat.x, seat.y, seat.z];
             g.on_ground = false;
             return;
         }
@@ -205,7 +205,9 @@ impl Game<'_> {
             return;
         };
         let [x, y, z] = p.position;
-        if !(x.is_finite() && y.is_finite() && z.is_finite())
+        if !x.is_finite()
+            || !y.is_finite()
+            || !z.is_finite()
             || !p.yaw.is_finite()
             || !p.pitch.is_finite()
         {
@@ -287,10 +289,11 @@ impl Game<'_> {
         b.previous_yaw = b.yaw;
         b.yaw = p.yaw;
         b.on_ground = p.on_ground;
+        let seat = self.player_boat_seat(i);
         let g = &mut host.hub.guests[gi];
         g.vehicle_good = Some([target.x, target.y, target.z]);
         g.previous_position = g.position;
-        g.position = [target.x, target.y + SEAT, target.z];
+        g.position = [seat.x, seat.y, seat.z];
     }
 
     /// `handlePaddleBoat`: the paddles of the boat the player drives.

crates/horizon-client/src/game/levels.rs

@@ -221,7 +221,7 @@ impl Game<'_> {
     /// holds it (`self.lan` is taken during the network tick).
     pub(super) fn enter_level(&mut self, host: Option<&mut LanHost>, target: Dim) -> Result<()> {
         // The in-frame game keeps its one level (`enter_dimension`).
-        if self.options.dedicated.is_none() {
+        if self.options.execution_role.is_client() {
             return Ok(());
         }
         if target != self.dim {
@@ -261,7 +261,7 @@ impl Game<'_> {
     /// nobody is in it; returns the level to put back afterwards. Only a
     /// server holds other levels.
     pub(super) fn enter_command_level(&mut self, dim: Dim) -> Option<Dim> {
-        if self.options.dedicated.is_none() || dim == self.dim {
+        if self.options.execution_role.is_client() || dim == self.dim {
             return None;
         }
         let back = self.dim;
@@ -296,7 +296,7 @@ impl Game<'_> {
             self.update_dedicated_streaming();
             self.update_world();
             result = if paused {
-                self.tick_lan();
+                self.tick_lan(true);
                 Ok(())
             } else if k == 0 {
                 self.tick()

crates/horizon-client/src/game/minecarts.rs

@@ -95,7 +95,7 @@ fn display_offset(kind: CartKind) -> f64 {
     if kind == CartKind::Hopper { 1.0 } else { 6.0 }
 }
 /// The minecart's passenger attachment minus Player.DEFAULT_VEHICLE_ATTACHMENT.
-const SEAT: f64 = 0.1875 - 0.6;
+pub(super) const SEAT: f64 = 0.1875 - 0.6;
 /// The placeholder container key under which an open cart's items live.
 pub(super) const CART_KEY_Y: i32 = -100_000;
 
@@ -686,40 +686,53 @@ impl Game<'_> {
             }
         }
     }
-    /// `AbstractMinecart.push(player)` when the player walks into a cart.
+    /// `AbstractMinecart.push` from each player walking into a cart
+    /// (`LivingEntity.pushEntities`): the window's player and every server
+    /// player (single player's own on its server thread, LAN guests). A
+    /// player in a vehicle pushes nothing here. The quarter push the player
+    /// gets back only moves the server's copy of it (`Entity.push` marks
+    /// `needsSync`, which `ServerEntity` sends to the other players only),
+    /// so no player feels it.
     fn push_carts(&mut self) {
-        let player = self.player.as_ref().map(|p| p.position);
-        let riding = self.riding;
-        for i in 0..self.carts.len() {
-            if Some(self.carts[i].id) == riding {
-                continue;
+        if self.carts.is_empty() {
+            return;
+        }
+        // (feet, box)
+        let mut pushers: Vec<(Vec3, Aabb)> = Vec::new();
+        if self.riding.is_none()
+            && let Some(p) = self.player.as_ref()
+        {
+            pushers.push((p.position, p.bounds()));
+        }
+        if let Some(host) = self.lan.as_ref() {
+            for g in host.hub.guests.iter().filter(|g| {
+                host.hub.here(g) && g.loaded && !g.dead && !g.spectator() && g.vehicle.is_none()
+            }) {
+                let [x, y, z] = g.position;
+                let height = if g.sneaking { 1.5 } else { 1.8 };
+                let bb = Aabb::new(
+                    Vec3::new(x - 0.3, y, z - 0.3),
+                    Vec3::new(x + 0.3, y + height, z + 0.3),
+                );
+                pushers.push((Vec3::new(x, y, z), bb));
             }
-            if let Some(pp) = player {
-                let bb = self.carts[i].bounds();
-                let (lo, hi) = (bb.min_position(), bb.max_position());
-                let touching = pp.x + 0.3 > lo.x
-                    && pp.x - 0.3 < hi.x
-                    && pp.z + 0.3 > lo.z
-                    && pp.z - 0.3 < hi.z
-                    && pp.y + 1.8 > lo.y
-                    && pp.y < hi.y;
-                if touching && riding.is_none() {
-                    let c = &mut self.carts[i];
-                    let (mut xa, mut za) = (pp.x - c.position.x, pp.z - c.position.z);
-                    let dd = xa * xa + za * za;
-                    if dd >= 1.0e-4 {
-                        let d = dd.sqrt();
-                        let pow = (1.0 / d).min(1.0);
-                        xa = xa / d * pow * f64::from(0.1f32) * 0.5;
-                        za = za / d * pow * f64::from(0.1f32) * 0.5;
-                        c.velocity.x -= xa;
-                        c.velocity.z -= za;
-                        if let Some(p) = self.player.as_mut() {
-                            p.velocity.x += xa / 4.0;
-                            p.velocity.z += za / 4.0;
-                        }
-                    }
+        }
+        for (feet, bb) in pushers {
+            for c in &mut self.carts {
+                if !bb.intersects(c.bounds()) {
+                    continue;
                 }
+                let (mut xa, mut za) = (feet.x - c.position.x, feet.z - c.position.z);
+                let dd = xa * xa + za * za;
+                if dd < f64::from(1.0e-4f32) {
+                    continue;
+                }
+                let d = dd.sqrt();
+                let pow = (1.0 / d).min(1.0);
+                xa = xa / d * pow * f64::from(0.1f32) * 0.5;
+                za = za / d * pow * f64::from(0.1f32) * 0.5;
+                c.velocity.x -= xa;
+                c.velocity.z -= za;
             }
         }
     }
@@ -797,7 +810,7 @@ impl Game<'_> {
         let ridden = self.guest_vehicles();
         // By id: an exploding cart can destroy or prime others mid-loop.
         let ids: Vec<u32> = self.carts.iter().map(|c| c.id).collect();
-        for id in ids {
+        for &id in &ids {
             let Some(i) = self.carts.iter().position(|c| c.id == id) else {
                 continue;
             };
@@ -823,6 +836,33 @@ impl Game<'_> {
                 self.carts.remove(i);
             }
         }
+        // On the server for every cart, the ridden ones too.
+        for id in ids {
+            if let Some(i) = self.carts.iter().position(|c| c.id == id) {
+                let p = self.carts[i].position;
+                if ticking(p.x.floor() as i32, p.z.floor() as i32) {
+                    self.cart_lava_tick(id);
+                }
+            }
+        }
+    }
+    /// `lavaHurt` twice a tick in lava: from `LavaFluid.entityInside` in the
+    /// behaviour's `applyEffectsFromBlocks`, then from `AbstractMinecart.tick`'s
+    /// own `isInLava`. The second breaks the cart, or primes a TNT minecart
+    /// (`MinecartTNT.destroy` for a fire source). A cart has no `baseTick`,
+    /// so the fire `lavaIgnite` lights never burns it.
+    fn cart_lava_tick(&mut self, id: u32) {
+        for _ in 0..2 {
+            let Some(i) = self.carts.iter().position(|c| c.id == id) else {
+                return;
+            };
+            if !self.in_lava(self.carts[i].bounds()) {
+                return;
+            }
+            let p = self.carts[i].position;
+            self.hurt_cart(i, 4.0, false, true);
+            self.lava_hurt_sound([p.x, p.y, p.z]);
+        }
     }
     /// `ClientPacketListener.postAddEntitySoundInstance` for the carts that
     /// joined the level since the last tick, and `LocalPlayer.startRiding`'s

crates/horizon-client/src/game/options.rs

@@ -237,15 +237,7 @@ impl Game<'_> {
                     let _ = std::fs::create_dir_all(&dir);
                     super::packs::open_folder(&dir);
                 }
-                Event::OpenShaderPackFolder => {
-                    let dir = horizon_client::shader_pack::folder();
-                    let _ = std::fs::create_dir_all(&dir);
-                    super::packs::open_folder(&dir);
-                }
                 Event::Credits => self.open_win_screen(false, super::win::Finish::Options),
-                Event::ReloadShaderPack => {
-                    self.load_shader_pack();
-                }
             }
         }
         Ok(())
@@ -294,14 +286,6 @@ impl Game<'_> {
             font.reset_cache();
             self.ui.chat.rescale(&self.gui.atlas);
         }
-        // A new renderer (resource reload, first window) takes the loaded pack.
-        let stale = self
-            .renderer
-            .as_ref()
-            .is_some_and(|r| r.shader_pack_id() != self.shader_packs.id());
-        if stale && let Err(e) = self.apply_shader_pack() {
-            log::warn!("Horizon: shader pack: {e}");
-        }
     }
     /// `Window.updateFullscreenState`: a fullscreen change made by the window
     /// system is adopted by the option (`Minecraft.fullscreenStateChanged`).

crates/horizon-client/src/game/packs.rs

@@ -4,7 +4,7 @@ use super::Game;
 use horizon_client::{
     hud::HudAtlas,
     lang,
-    pack_screen::{Compat, PackInfo, Source as PackSource},
+    pack_screen::{self, Compat, PackInfo, Source as PackSource},
     packs::{self, Pack, Position},
     text::{Style, Text},
 };
@@ -34,10 +34,16 @@ pub fn open_folder(dir: &Path) {
         log::warn!("Horizon: could not open {}: {e}", dir.display());
     }
 }
-/// The resource root to load from, given the vanilla root and the selection.
-pub fn startup_root(vanilla: &Path, selected: &[String]) -> std::io::Result<PathBuf> {
+/// The resource root to load from, given the vanilla root, the selection and
+/// a server's packs, which go on top (`Pack.Position.TOP`, fixed).
+pub fn startup_root(
+    vanilla: &Path,
+    selected: &[String],
+    server: &[Pack],
+) -> std::io::Result<PathBuf> {
     let all = packs::discover(vanilla, &packs_dir());
-    let enabled = packs::enabled(&all, selected);
+    let mut enabled = packs::enabled(&all, selected);
+    enabled.extend_from_slice(server);
     packs::resource_root(vanilla, &enabled, &cache_dir())
 }
 fn info(p: &Pack) -> PackInfo {
@@ -53,14 +59,15 @@ fn info(p: &Pack) -> PackInfo {
             PackSource::Default
         },
         compat: p.compatibility,
-        icon: p.icon,
+        icon: p.icon_png().as_deref().and_then(pack_screen::load_icon),
         required: false,
         position: Position::Top,
         fixed: false,
     }
 }
-/// The vanilla pack: required, at the bottom (`BuiltInPackSource`).
-fn vanilla_info() -> PackInfo {
+/// The vanilla pack: required, at the bottom (`BuiltInPackSource`), with the
+/// client JAR's `pack.png` that the prepared resources hold.
+fn vanilla_info(vanilla: &Path) -> PackInfo {
     PackInfo {
         id: "vanilla".into(),
         title: Text::translate("resourcePack.vanilla.name", &[]),
@@ -68,7 +75,10 @@ fn vanilla_info() -> PackInfo {
         description_style: Style::default(),
         source: PackSource::BuiltIn,
         compat: Compat::Compatible,
-        icon: true,
+        icon: std::fs::read(vanilla.join("pack.png"))
+            .ok()
+            .as_deref()
+            .and_then(pack_screen::load_icon),
         required: true,
         position: Position::Bottom,
         fixed: false,
@@ -80,7 +90,7 @@ pub(super) fn pack_infos(vanilla: &Path) -> Vec<PackInfo> {
         .iter()
         .map(info)
         .collect();
-    infos.push(vanilla_info());
+    infos.push(vanilla_info(vanilla));
     infos
 }
 impl Game<'_> {
@@ -113,14 +123,7 @@ impl Game<'_> {
             self.pending_pack_reload = true;
             return;
         }
-        let vanilla = self.vanilla_root();
-        if self.ui.vanilla_root.as_os_str().is_empty() {
-            self.ui.vanilla_root = vanilla.clone();
-        }
-        let result = startup_root(&vanilla, &self.settings.resource_packs)
-            .map_err(Into::into)
-            .and_then(|root| self.reload_resources(&root));
-        if let Err(e) = result {
+        if let Err(e) = self.reload_selected_packs() {
             log::warn!("Horizon: resource reload failed: {e}");
             if self.screen != super::Screen::Options {
                 self.open_options_at(
@@ -131,6 +134,16 @@ impl Game<'_> {
             self.ui.options.resource_error = Some(e.to_string());
         }
     }
+    /// Reload from the selected packs and the server's.
+    pub(super) fn reload_selected_packs(&mut self) -> horizon_client::Result<()> {
+        let vanilla = self.vanilla_root();
+        if self.ui.vanilla_root.as_os_str().is_empty() {
+            self.ui.vanilla_root = vanilla.clone();
+        }
+        let server = &self.server_packs.active;
+        let root = startup_root(&vanilla, &self.settings.resource_packs, server)?;
+        self.reload_resources(&root)
+    }
     fn reload_resources(&mut self, root: &Path) -> horizon_client::Result<()> {
         let render = std::sync::Arc::new(self.pack.assets.reload(root)?);
         let mut atlas = HudAtlas::build_over(root, &self.vanilla_root())?;

crates/horizon-client/src/game/passengers.rs

@@ -38,9 +38,16 @@ impl Game<'_> {
             m.extra.rider = Some(rider);
         }
     }
-    /// Riders sit on their vehicles (`Entity.positionRider`), and let go when
-    /// the vehicle dies or is gone.
+    /// Riders sit on their vehicles (`Entity.positionRider`), mobs or boats,
+    /// and let go when the vehicle dies or is gone.
     pub(super) fn sync_riders(&mut self) {
+        // Entity.baseTick.
+        for m in &mut self.mobs {
+            if m.extra.boarding_cooldown > 0 {
+                m.extra.boarding_cooldown -= 1;
+            }
+        }
+        let boats: std::collections::HashSet<u32> = self.boats.iter().map(|b| b.id).collect();
         let index: HashMap<u32, usize> = self
             .mobs
             .iter()
@@ -54,9 +61,10 @@ impl Game<'_> {
             };
             let valid = self.mobs[i].alive()
                 && !self.mobs[i].removed
-                && index
-                    .get(&v)
-                    .is_some_and(|&j| self.mobs[j].alive() && !self.mobs[j].removed);
+                && (boats.contains(&v)
+                    || index
+                        .get(&v)
+                        .is_some_and(|&j| self.mobs[j].alive() && !self.mobs[j].removed));
             if valid {
                 riding.insert(v, self.mobs[i].id);
             } else {
@@ -68,6 +76,19 @@ impl Game<'_> {
         for m in &mut self.mobs {
             m.extra.rider = riding.get(&m.id).copied();
         }
+        self.position_riders();
+    }
+    /// `Entity.positionRider` for every mob passenger: in its boat, then on
+    /// its mob. A server's client places them itself too, as the server sends
+    /// no passenger's position.
+    pub(super) fn position_riders(&mut self) {
+        self.seat_boat_mobs();
+        let index: HashMap<u32, usize> = self
+            .mobs
+            .iter()
+            .enumerate()
+            .map(|(i, m)| (m.id, i))
+            .collect();
         // Riders of riders settle over a few passes.
         for _ in 0..3 {
             for i in 0..self.mobs.len() {

crates/horizon-client/src/game/persist.rs

@@ -156,6 +156,8 @@ impl Game<'_> {
                     kind.as_str(),
                     "minecraft:experience_orb"
                         | "minecraft:arrow"
+                        | "minecraft:fireball"
+                        | "minecraft:small_fireball"
                         | "minecraft:falling_block"
                         | "minecraft:end_crystal"
                         | "minecraft:ender_dragon"
@@ -195,6 +197,11 @@ impl Game<'_> {
                             self.creatures.projectiles.push(p);
                         }
                     }
+                    "minecraft:fireball" | "minecraft:small_fireball" => {
+                        if let Some(p) = entity_nbt::fireball_from_nbt(&tag, player_uuid) {
+                            self.creatures.projectiles.push(p);
+                        }
+                    }
                     "minecraft:falling_block" => {
                         if let Some((state, position, velocity, age, fall_distance)) =
                             entity_nbt::falling_block_from_nbt(&tag)
@@ -243,6 +250,8 @@ impl Game<'_> {
                         .is_some_and(|(wood, chest)| self.boat_models.has(wood, chest)) =>
                     {
                         if let Some((position, velocity, yaw)) = entity_nbt::boat_from_nbt(&tag) {
+                            let mut tag = tag;
+                            let riders = self.take_mob_passengers(&mut tag);
                             self.next_entity += 1;
                             let id = self.next_entity;
                             let (wood, chest) =
@@ -263,6 +272,9 @@ impl Game<'_> {
                             b.velocity = velocity;
                             self.remember(id, uuid, tag);
                             self.boats.push(b);
+                            for rider in riders {
+                                self.load_mob(rider, Some(id));
+                            }
                         }
                     }
                     k if super::minecarts::CartKind::from_id(k).is_some() => {
@@ -341,25 +353,10 @@ impl Game<'_> {
         // Structure entities placed with finalizeEntities.
         let mut tag = tag;
         let mut finalize = false;
-        let mut riders = Vec::new();
-        let mut unknown = Vec::new();
         if let Tag::Compound(c) = &mut tag {
             finalize = c.remove(&"horizon:finalize".into()).is_some();
-            if let Some(Tag::List(list)) = c.remove(&"Passengers".into()) {
-                for p in list {
-                    let known =
-                        entity_nbt::kind(&p).is_some_and(|k| self.res.mob_types().contains_key(&k));
-                    if known {
-                        riders.push(p);
-                    } else {
-                        unknown.push(p);
-                    }
-                }
-            }
-            if !unknown.is_empty() {
-                c.insert("Passengers".into(), Tag::List(unknown));
-            }
         }
+        let riders = self.take_mob_passengers(&mut tag);
         let mut m = entity_nbt::mob_from_nbt(&tag, self.res.mob_types(), self.next_entity)?;
         m.extra.mount = mount;
         m.extra.passenger = mount.is_some();
@@ -401,6 +398,49 @@ impl Game<'_> {
         }
         Some(id)
     }
+    /// The mobs under an entity's `Passengers`, taken out of it; the
+    /// passengers Horizon doesn't simulate stay.
+    fn take_mob_passengers(&self, tag: &mut Tag) -> Vec<Tag> {
+        let mut riders = Vec::new();
+        if let Tag::Compound(c) = tag
+            && let Some(Tag::List(list)) = c.remove(&"Passengers".into())
+        {
+            let mut unknown = Vec::new();
+            for p in list {
+                let known =
+                    entity_nbt::kind(&p).is_some_and(|k| self.res.mob_types().contains_key(&k));
+                if known {
+                    riders.push(p);
+                } else {
+                    unknown.push(p);
+                }
+            }
+            if !unknown.is_empty() {
+                c.insert("Passengers".into(), Tag::List(unknown));
+            }
+        }
+        riders
+    }
+    /// The mobs riding entity `id` under `tag`'s `Passengers`, after the
+    /// passengers it kept from loading.
+    fn put_mob_passengers(&mut self, tag: &mut Tag, id: u32) {
+        let riders: Vec<usize> = (0..self.mobs.len())
+            .filter(|&j| self.mobs[j].extra.mount == Some(id) && self.mobs[j].alive())
+            .collect();
+        let riders: Vec<Tag> = riders.into_iter().map(|j| self.mob_tree_nbt(j)).collect();
+        if let Tag::Compound(c) = tag {
+            let mut list = match c.get(&"Passengers".into()) {
+                Some(Tag::List(l)) => l.clone(),
+                _ => Vec::new(),
+            };
+            list.extend(riders);
+            if list.is_empty() {
+                c.remove(&"Passengers".into());
+            } else {
+                c.insert("Passengers".into(), Tag::List(list));
+            }
+        }
+    }
     /// An entity of a type Horizon does not simulate, kept as its compound.
     fn load_other(&mut self, tag: Tag, kind: &str) -> Option<u32> {
         let position = entity_nbt::position(&tag)?;
@@ -476,22 +516,7 @@ impl Game<'_> {
         let uuid = self.uuid_for(id);
         let mut tag = entity_nbt::mob_to_nbt(&self.mobs[i], uuid, self.persist.raw.get(&id));
         self.write_leash(&mut tag, i);
-        let riders: Vec<usize> = (0..self.mobs.len())
-            .filter(|&j| self.mobs[j].extra.mount == Some(id) && self.mobs[j].alive())
-            .collect();
-        let riders: Vec<Tag> = riders.into_iter().map(|j| self.mob_tree_nbt(j)).collect();
-        if let Tag::Compound(c) = &mut tag {
-            let mut list = match c.get(&"Passengers".into()) {
-                Some(Tag::List(l)) => l.clone(),
-                _ => Vec::new(),
-            };
-            list.extend(riders);
-            if list.is_empty() {
-                c.remove(&"Passengers".into());
-            } else {
-                c.insert("Passengers".into(), Tag::List(list));
-            }
-        }
+        self.put_mob_passengers(&mut tag, id);
         tag
     }
     /// Forget an entity that left the world (its UUID and loaded compound).
@@ -569,10 +594,15 @@ impl Game<'_> {
         let mut out: HashMap<(i32, i32), Vec<Tag>> =
             keys.iter().map(|k| (*k, Vec::new())).collect();
         let player_uuid = self.level.player_uuid;
-        // A rider is saved inside its root vehicle, in the root's chunk.
+        // A rider is saved inside its root vehicle, in the root's chunk; a
+        // boat's passengers inside the boat.
         let mobs: Vec<usize> = (0..self.mobs.len())
             .filter(|&i| {
                 self.mob_root(i) == i
+                    && self.mobs[i]
+                        .extra
+                        .mount
+                        .is_none_or(|v| self.boats.iter().all(|b| b.id != v))
                     && keys.contains(&chunk_of(self.mobs[i].position))
                     && self.mobs[i].alive()
             })
@@ -619,13 +649,15 @@ impl Game<'_> {
             } else {
                 None
             };
-            let (uuid, raw) = anon(&self.persist, "minecraft:arrow", p.position);
+            let (uuid, raw) = anon(&self.persist, p.kind.id(), p.position);
             let in_block = p
                 .arrow
                 .as_ref()
                 .and_then(|a| a.last_state)
                 .map(|s| self.state_to_nbt(s));
-            if let Some(tag) = entity_nbt::arrow_to_nbt(p, uuid, owner, in_block, raw.as_ref()) {
+            let tag = entity_nbt::arrow_to_nbt(p, uuid, owner, in_block, raw.as_ref())
+                .or_else(|| entity_nbt::fireball_to_nbt(p, uuid, owner, raw.as_ref()));
+            if let Some(tag) = tag {
                 out.entry(chunk_of(p.position)).or_default().push(tag);
             }
         }
@@ -650,25 +682,29 @@ impl Game<'_> {
                     .push(with_raw(tag, raw.as_ref()));
             }
         }
-        for b in &self.boats {
-            if keys.contains(&chunk_of(b.position)) {
-                let uuid = self
-                    .persist
-                    .uuids
-                    .get(&b.id)
-                    .copied()
-                    .unwrap_or_else(random_uuid);
-                let tag = entity_nbt::boat_to_nbt(
-                    &b.entity_type(),
-                    b.position,
-                    b.velocity,
-                    b.yaw,
-                    uuid,
-                    self.persist.raw.get(&b.id),
-                    b.chest.then_some(&b.items[..]),
-                );
-                out.entry(chunk_of(b.position)).or_default().push(tag);
-            }
+        let boats: Vec<usize> = (0..self.boats.len())
+            .filter(|&i| keys.contains(&chunk_of(self.boats[i].position)))
+            .collect();
+        for i in boats {
+            let b = &self.boats[i];
+            let (id, at) = (b.id, b.position);
+            let uuid = self
+                .persist
+                .uuids
+                .get(&id)
+                .copied()
+                .unwrap_or_else(random_uuid);
+            let mut tag = entity_nbt::boat_to_nbt(
+                &b.entity_type(),
+                b.position,
+                b.velocity,
+                b.yaw,
+                uuid,
+                self.persist.raw.get(&id),
+                b.chest.then_some(&b.items[..]),
+            );
+            self.put_mob_passengers(&mut tag, id);
+            out.entry(chunk_of(at)).or_default().push(tag);
         }
         if let Some(d) = &self.dragon
             && keys.contains(&chunk_of(d.position))
@@ -833,9 +869,16 @@ impl Game<'_> {
                 }
                 keep
             });
-            // Riders leave with their root vehicle.
+            // Riders leave with their root vehicle, a boat's with the boat.
             let leaving: HashSet<u32> = (0..self.mobs.len())
-                .filter(|&i| gone(self.mobs[self.mob_root(i)].position))
+                .filter(|&i| {
+                    let r = self.mob_root(i);
+                    match self.mobs[r].extra.mount {
+                        Some(v) if removed.contains(&v) => true,
+                        Some(v) if self.boats.iter().any(|b| b.id == v) => false,
+                        _ => gone(self.mobs[r].position),
+                    }
+                })
                 .map(|i| self.mobs[i].id)
                 .collect();
             self.mobs.retain(|m| {

crates/horizon-client/src/game/raids.rs

@@ -6,7 +6,6 @@ use super::{Dim, Game};
 use horizon_client::mobs::villager as mobs_villager;
 use horizon_client::{
     effects::{EffectInstance, OmenTick},
-    hud_overlays,
     mobs::{
         Mob, Species, raider,
         spawn_rules::{self, SpawnLevel},
@@ -15,9 +14,9 @@ use horizon_client::{
     },
     patrol::{GameplayAttributes, Member, PatrolLevel, PatrolSpawner},
     raid::{self, Action, BarName, RaidLevel, RaidPlayer, RaiderInfo, RaiderType, Raids, Spawn},
-    text::Text,
 };
 use horizon_core::{geometry::Vec3, random::RandomSource};
+use horizon_world::nbt::Tag;
 use std::collections::{HashMap, HashSet};
 
 /// Patrol and raid state owned by the game.
@@ -1063,37 +1062,18 @@ impl Game<'_> {
         }
     }
 
-    /// The raid boss bars: red and notched in tens, with the raid's title.
-    pub(super) fn raid_bars(&self, bars: &mut Vec<hud_overlays::BossBar>) {
-        for raid in self.raiding.raids.map.values() {
-            if !raid.bar.visible || !raid.bar.player || raid.is_stopped() {
-                continue;
-            }
-            let title = self.translate("event.minecraft.raid", "Raid");
-            let name = match raid.bar.name {
-                BarName::Raid => title,
-                BarName::Remaining(n) => format!(
-                    "{title} - {}",
-                    self.translate(
-                        "event.minecraft.raid.raiders_remaining",
-                        "Raiders Remaining: %s"
-                    )
-                    .replace("%s", &n.to_string())
-                ),
-                BarName::Victory => {
-                    self.translate("event.minecraft.raid.victory.full", "Raid - Victory")
-                }
-                BarName::Defeat => {
-                    self.translate("event.minecraft.raid.defeat.full", "Raid - Defeat")
-                }
-            };
-            bars.push(hud_overlays::BossBar {
-                name: Text::literal(name),
-                progress: raid.bar.progress,
-                color: 2,
-                overlay: 2,
-            });
+    /// The raid bar a living player at `at` is in (`Raid.getPlayers`): red,
+    /// notched in tens. The name is the translate component the client draws.
+    pub(super) fn raid_boss_at(&self, at: [f64; 3], alive: bool) -> Option<(i32, Tag, f32)> {
+        if !alive || self.dim != Dim::Overworld {
+            return None;
         }
+        let block = block_of(Vec3::new(at[0], at[1], at[2]));
+        let (id, raid) = self.raiding.raids.nearby(block)?;
+        if !raid.bar.visible || raid.is_stopped() {
+            return None;
+        }
+        Some((id, raid_name_tag(raid.bar.name), raid.bar.progress))
     }
     /// A firework a villager launches to celebrate (`CelebrateVillagersSurvivedRaid`).
     pub(super) fn villager_firework(&mut self, at: [f64; 3], color: usize, flight: u8) {
@@ -1239,6 +1219,36 @@ impl Game<'_> {
     }
 }
 
+/// `Raid.raidEvent`'s name: the raid title, the remaining-raiders line, or
+/// the victory and defeat lines.
+fn raid_name_tag(name: BarName) -> Tag {
+    let key = |k: &str| Tag::compound([("translate", Tag::String(k.into()))]);
+    match name {
+        BarName::Raid => key("event.minecraft.raid"),
+        BarName::Victory => key("event.minecraft.raid.victory.full"),
+        BarName::Defeat => key("event.minecraft.raid.defeat.full"),
+        BarName::Remaining(n) => Tag::compound([
+            ("translate", Tag::String("event.minecraft.raid".into())),
+            (
+                "extra",
+                Tag::List(vec![
+                    Tag::String(" - ".into()),
+                    Tag::compound([
+                        (
+                            "translate",
+                            Tag::String("event.minecraft.raid.raiders_remaining".into()),
+                        ),
+                        (
+                            "with",
+                            Tag::List(vec![Tag::String(n.to_string().as_str().into())]),
+                        ),
+                    ]),
+                ]),
+            ),
+        ]),
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

crates/horizon-client/src/game/remote.rs

@@ -140,9 +140,13 @@ pub(super) struct Remote {
     stepped: HashMap<i32, SteppedInterpolation>,
     /// `LivingEntity.lerpHeadTo`: the head yaw and the ticks left to reach it.
     head_lerps: HashMap<i32, (f32, u32)>,
-    /// Item entities waiting for their item data.
-    pending_items: HashMap<i32, [f64; 3]>,
+    /// Item entities waiting for their item data: where they are and their
+    /// motion.
+    pending_items: HashMap<i32, ([f64; 3], Vec3)>,
     health: (f32, i32, f32),
+    /// `LocalPlayer.flashOnSetHealth`: set by the first health the server
+    /// sends; from then on a drop starts the hurt animation.
+    flash_on_set_health: bool,
     game_mode: i32,
     pub chat: Vec<(String, Instant)>,
     /// Lines received since joining, for the control socket's events.
@@ -189,6 +193,9 @@ pub(super) struct Remote {
     /// the oldest of them first waited (`poll_remote`).
     backlog: VecDeque<Event>,
     backlog_since: Option<Instant>,
+    /// `ClientboundTransferPacket`'s target: when the connection ends the
+    /// game connects here, the stored cookies carried over (`TransferState`).
+    transfer: Option<String>,
 }
 
 /// The time a frame spends on chunk packets before it leaves the rest of
@@ -253,14 +260,25 @@ fn number_format(f: &play::NumberFormat) -> horizon_client::scoreboard::NumberFo
 impl Game<'_> {
     /// Leave the title for a server (ConnectScreen): an empty world fed by the connection.
     pub(super) fn connect_server(&mut self, address: &str, name: &str) -> Result<()> {
+        self.connect_server_with_cookies(address, name, None)
+    }
+    /// `connect_server` carrying a transfer's stored server cookies
+    /// (`TransferState`); None on an ordinary join.
+    pub(super) fn connect_server_with_cookies(
+        &mut self,
+        address: &str,
+        name: &str,
+        cookies: Option<horizon_client::net::Cookies>,
+    ) -> Result<()> {
         if self.defer_world_entry(super::PendingWorldEntry::Server {
             address: address.to_owned(),
             name: name.to_owned(),
+            cookies: cookies.clone(),
         })? {
             return Ok(());
         }
         self.join_world_rest()?;
-        if let Err(error) = self.join_server(address, name, None) {
+        if let Err(error) = self.join_server(address, name, None, cookies) {
             log::warn!("Horizon: could not join server: {error}");
             if self.title.is_none() {
                 self.title = Some(horizon_client::title::Title::new(
@@ -281,13 +299,14 @@ impl Game<'_> {
         pipe: horizon_protocol::connection::Pipe,
         name: &str,
     ) -> Result<()> {
-        self.join_server("local", name, Some(pipe))
+        self.join_server("local", name, Some(pipe), None)
     }
     fn join_server(
         &mut self,
         address: &str,
         name: &str,
         local: Option<horizon_protocol::connection::Pipe>,
+        cookies: Option<horizon_client::net::Cookies>,
     ) -> Result<()> {
         self.perf.world_opening();
         let root = self.options.resources.clone();
@@ -305,11 +324,31 @@ impl Game<'_> {
         // A signed-in account always plays under its own name.
         let auth = horizon_client::auth::current();
         let name = auth.as_ref().map_or(name, |a| a.name.as_str());
+        let user = auth.as_ref().map_or_else(
+            || {
+                (
+                    name.to_owned(),
+                    horizon_protocol::crypto::offline_uuid(name),
+                )
+            },
+            |a| (a.name.clone(), a.uuid),
+        );
+        self.server_packs_connect(local.is_none().then_some(address), user);
         let session = match local {
             Some(pipe) => Session::connect_local(pipe, name, view, lang.clone()),
             None => {
                 self.extras_connecting(address, name);
-                Session::connect(address, name, auth.clone(), view, lang.clone())
+                match cookies {
+                    Some(cookies) => Session::connect_transferred(
+                        address,
+                        name,
+                        auth.clone(),
+                        view,
+                        lang.clone(),
+                        cookies,
+                    ),
+                    None => Session::connect(address, name, auth.clone(), view, lang.clone()),
+                }
             }
         };
         let player_type = super::perspective::player_type(&root);
@@ -369,6 +408,7 @@ impl Game<'_> {
         }
         self.apply_settings();
         self.clear_waypoints();
+        self.boss_overlay.reset();
         self.remote = Some(Remote {
             session,
             brand: "unknown".into(),
@@ -401,6 +441,7 @@ impl Game<'_> {
             head_lerps: HashMap::new(),
             pending_items: HashMap::new(),
             health: (20.0, 20, 5.0),
+            flash_on_set_health: false,
             game_mode: 0,
             chat: Vec::new(),
             chat_received: 0,
@@ -430,6 +471,7 @@ impl Game<'_> {
             chunk_center: (0, 0),
             backlog: VecDeque::new(),
             backlog_since: None,
+            transfer: None,
         });
         // The level's TickRateManager follows the server's ticking packets.
         self.clock = horizon_client::clock::FixedStep::client();
@@ -450,9 +492,11 @@ impl Game<'_> {
             self.extras_left();
         }
         self.clear_waypoints();
+        self.boss_overlay.reset();
         if let Some(mut r) = self.remote.take() {
             r.session.disconnect();
         }
+        self.server_packs_disconnect();
         // Single player's server thread saves the world before the title shows.
         let single_player = match self.integrated.take() {
             Some(server) => {
@@ -544,7 +588,7 @@ impl Game<'_> {
     /// (`LivingEntity.forceAddEffect`): the effect replaces any of its kind.
     /// Other entities' effects are not shown.
     fn remote_effect(&mut self, p: &play::UpdateMobEffect) {
-        if !self.remote.as_ref().is_some_and(|r| r.entity_id == p.id) {
+        if self.remote.as_ref().is_none_or(|r| r.entity_id != p.id) {
             return;
         }
         let Some(id) = self.remote_effect_id(p.effect) else {
@@ -596,6 +640,21 @@ impl Game<'_> {
                 continue;
             };
             let value = match c {
+                // Read past, not decoded: the item keeps its prototype's value.
+                Component::Raw(_) => continue,
+                // Trim materials and patterns are synced registries, as enchantments are.
+                Component::Trim { material, pattern } => {
+                    let (Some(material), Some(pattern)) = (
+                        r.registries.name("minecraft:trim_material", *material),
+                        r.registries.name("minecraft:trim_pattern", *pattern),
+                    ) else {
+                        continue;
+                    };
+                    Tag::compound([
+                        ("material", Tag::String(material.into())),
+                        ("pattern", Tag::String(pattern.into())),
+                    ])
+                }
                 Component::Int(v) if *kind == component::RARITY => {
                     let rarity = ["common", "uncommon", "rare", "epic"];
                     Tag::String(rarity.get(*v as usize).copied().unwrap_or("common").into())
@@ -722,6 +781,9 @@ impl Game<'_> {
             self.ticks,
             self.screen == Screen::Chat,
         );
+        if self.mods.running() {
+            self.mods_chat(&text);
+        }
         if let Some(r) = self.remote.as_mut() {
             r.chat.push((text, Instant::now()));
             r.chat_received += 1;
@@ -818,7 +880,11 @@ impl Game<'_> {
                         r.joined = true;
                         r.profile = uuid;
                         r.profile_name = name.clone();
-                        r.status = format!("Joined as {name}; loading terrain...");
+                        // LevelLoadingScreen's line: no player name.
+                        r.status = horizon_client::lang::get_or(
+                            "multiplayer.downloadingTerrain",
+                            "Loading terrain...",
+                        );
                     }
                 }
                 Event::Brand(brand) => {
@@ -827,6 +893,17 @@ impl Game<'_> {
                     }
                 }
                 Event::Reconfigured(registries) => self.set_registries(registries),
+                // handleTransfer: "Cannot transfer to server from
+                // singleplayer" (no ServerData), so the world just closes.
+                Event::Transfer { host, port } => {
+                    if let Some(r) = self.remote.as_mut()
+                        && r.session.address != "local"
+                    {
+                        r.transfer = Some(format!("{host}:{port}"));
+                    }
+                }
+                Event::PackPush(p) => self.handle_pack_push(p),
+                Event::PackPop(id) => self.handle_pack_pop(id),
                 Event::DecodeError(e) => {
                     if let Some(r) = self.remote.as_mut() {
                         r.decode_errors += 1;
@@ -840,6 +917,20 @@ impl Game<'_> {
                     from_server,
                 } => {
                     log::info!("Horizon: disconnected: {reason}");
+                    // ClientboundTransferPacket left a target: connect there
+                    // instead of showing the disconnect, the stored cookies
+                    // carried over (ClientCommonPacketListenerImpl.
+                    // handleTransfer → ConnectScreen.startConnecting).
+                    let transfer = self.remote.as_mut().and_then(|r| {
+                        r.transfer.take().map(|address| {
+                            (address, r.session.name.clone(), r.session.cookies.clone())
+                        })
+                    });
+                    if let Some((address, name, cookies)) = transfer {
+                        self.leave_server(None)?;
+                        self.connect_server_with_cookies(&address, &name, Some(cookies))?;
+                        return Ok(());
+                    }
                     let retry = self.reconnect_after(&reason, from_server);
                     self.leave_server(Some(reason))?;
                     self.offer_reconnect(retry);
@@ -973,6 +1064,9 @@ impl Game<'_> {
                 r.stepped.clear();
                 r.head_lerps.clear();
                 r.pending_items.clear();
+                // The entity ids are the old world's; the new dimension's
+                // player entities re-map to their profiles on AddEntity.
+                r.level_players.clear();
                 // A new ClientLevel: a new chunk storage, centred on 0, 0.
                 r.chunk_center = (0, 0);
             }
@@ -1369,7 +1463,7 @@ impl Game<'_> {
         }
         if let Some(r) = self.remote.as_mut() {
             if kind == "minecraft:item" {
-                r.pending_items.insert(id, position);
+                r.pending_items.insert(id, (position, Vec3::ZERO));
             }
             r.entities.insert(
                 id,
@@ -1448,6 +1542,23 @@ impl Game<'_> {
                 m.on_ground = on_ground;
                 return;
             }
+            if let Some(p) = r.pending_items.get_mut(&id) {
+                p.0 = position;
+            }
+            // ItemEntity and FallingBlockEntity keep Entity's NO_OP
+            // InterpolationHandler: moveOrInterpolateTo puts them there at
+            // once, and their own tick moves them on between the server's
+            // updates (`tick_remote_entities`).
+            let at = Vec3::new(position[0], position[1], position[2]);
+            if let Some(d) = self.dropped.iter_mut().find(|d| d.id == id as u32) {
+                d.position = at;
+                d.on_ground = on_ground;
+                return;
+            }
+            if let Some(f) = self.falling.iter_mut().find(|f| f.id == id as u32) {
+                f.position = at;
+                return;
+            }
             // AbstractInterpolationHandler.interpolateTo: without a rotation,
             // the one it was heading for.
             let rotation = rotation.or_else(|| r.lerps.get(&id).and_then(|l| l.rotation));
@@ -1459,11 +1570,9 @@ impl Game<'_> {
                     steps: 3,
                 },
             );
-            if let Some(p) = r.pending_items.get_mut(&id) {
-                *p = position;
-            }
         }
         self.turn_remote_object(id, rotation.map(|(yaw, _)| yaw), on_ground);
+        self.move_remote_text_display(id, position, rotation);
         self.turn_remote_projectile(id, rotation);
     }
     fn remove_entity(&mut self, id: i32) {
@@ -1569,6 +1678,12 @@ impl Game<'_> {
             }
         }
     }
+    /// Find a game slot in the menu's complete, contiguous slot mapping.
+    fn menu_slot_index(menu: &str, internal: usize) -> Option<usize> {
+        (0..)
+            .map_while(|slot| Self::menu_slot(menu, slot))
+            .position(|slot| slot == internal)
+    }
     /// The workstation screen of a menu type a server opens.
     pub(super) fn remote_station_kind(menu: &str) -> Option<super::stations::Kind> {
         use super::stations::Kind;
@@ -1773,6 +1888,9 @@ impl Game<'_> {
                     self.audio.play(&name, Some(at), p.volume, p.pitch);
                 }
             }
+            C::StopSound(p) => self
+                .audio
+                .stop_sounds(p.sound.as_deref(), p.source.map(|s| s as usize)),
             C::AddEntity(p) => {
                 let kind = self
                     .remote
@@ -1794,6 +1912,8 @@ impl Game<'_> {
                     }
                 }
                 self.spawn_entity(p.id, &kind, p.position, rotation);
+                // Entity.recreateFromPacket: setDeltaMovement(packet.getMovement()).
+                self.remote_motion(p.id, p.velocity);
                 if !self.spawn_remote_object(p.id, &kind, p.position, rotation[0], p.data) {
                     self.spawn_remote_projectile(
                         p.id,
@@ -1804,6 +1924,7 @@ impl Game<'_> {
                         p.data,
                     );
                 }
+                self.move_remote_text_display(p.id, p.position, Some((rotation[0], rotation[1])));
             }
             C::RemoveEntities(p) => {
                 for id in p.ids {
@@ -2112,17 +2233,29 @@ impl Game<'_> {
                     pl.velocity = Vec3::new(p.velocity[0], p.velocity[1], p.velocity[2]);
                 }
             }
+            // The same packet for another entity: Entity.lerpMotion.
+            C::SetEntityMotion(p) => self.remote_motion(p.id, p.velocity),
             // ClientPacketListener.handleDamageEvent: LivingEntity.handleDamageEvent
             // jolts the walk animation and restarts the hurt flash. Its hurt
             // sound comes as a sound from Horizon's host, which plays it itself.
+            // This player's own hurt tilt and flash come from the server too
+            // (sent to the player itself): its own moves never hurt it.
             C::DamageEvent(p) => {
-                if let Some(m) = self.mobs.iter_mut().find(|m| m.id == p.id as u32) {
+                if self.remote.as_ref().is_some_and(|r| r.entity_id == p.id) {
+                    if let Some(pl) = self.player.as_mut() {
+                        pl.health.animate_hurt();
+                    }
+                } else if let Some(m) = self.mobs.iter_mut().find(|m| m.id == p.id as u32) {
                     m.limb_speed = 1.5;
                     m.hurt_time = 10;
                 }
             }
             C::HurtAnimation(p) => {
-                if let Some(m) = self.mobs.iter_mut().find(|m| m.id == p.id as u32) {
+                if self.remote.as_ref().is_some_and(|r| r.entity_id == p.id) {
+                    if let Some(pl) = self.player.as_mut() {
+                        pl.health.animate_hurt();
+                    }
+                } else if let Some(m) = self.mobs.iter_mut().find(|m| m.id == p.id as u32) {
                     m.hurt_time = 10;
                 }
             }
@@ -2188,9 +2321,14 @@ impl Game<'_> {
                 self.remote_world_options_difficulty(self.ui.difficulty, p.locked);
             }
             C::GameRuleValues(p) => self.remote_world_options_rules(p.entries),
+            // ClientPacketListener.handleSetHealth: LocalPlayer.hurtTo.
             C::SetHealth(p) => {
-                if let Some(r) = self.remote.as_mut() {
+                let flash = self.remote.as_mut().is_some_and(|r| {
                     r.health = (p.health, p.food, p.saturation);
+                    std::mem::replace(&mut r.flash_on_set_health, true)
+                });
+                if flash && let Some(pl) = self.player.as_mut() {
+                    pl.health.flash_health_change(p.health);
                 }
                 self.apply_remote_health();
                 if p.health <= 0.0 && self.screen != Screen::Dead && self.player.is_some() {
@@ -2640,6 +2778,7 @@ impl Game<'_> {
             }
             // ClientPacketListener.setActionBarText, setTitleText,
             // setSubtitleText, setTitlesAnimation and handleTitlesClear.
+            C::BossEvent(p) => self.apply_boss_event(&p),
             C::SetActionBarText(p) => self.titles.set_overlay(remote_text(&p.text), false),
             C::SetTitleText(p) => self.titles.set_title(remote_text(&p.text)),
             C::SetSubtitleText(p) => self.titles.set_subtitle(remote_text(&p.text)),
@@ -2920,7 +3059,9 @@ impl Game<'_> {
             item.stack = stack;
             return;
         }
-        let Some(p) = position else { return };
+        let Some((p, velocity)) = position else {
+            return;
+        };
         let at = Vec3::new(p[0], p[1], p[2]);
         let bob_offset = self.world.random.next_float() * std::f32::consts::PI * 2.0;
         self.dropped.push(ItemEntity {
@@ -2931,7 +3072,7 @@ impl Game<'_> {
             stack,
             position: at,
             previous: at,
-            velocity: Vec3::ZERO,
+            velocity,
             on_ground: false,
             age: 0,
             pickup_delay: 0,
@@ -2939,6 +3080,23 @@ impl Game<'_> {
             ticks: 0,
         });
     }
+    /// `Entity.lerpMotion` (and `recreateFromPacket`'s motion) for the
+    /// entities whose own tick moves them on a client: dropped items and
+    /// falling blocks.
+    fn remote_motion(&mut self, id: i32, velocity: [f64; 3]) {
+        let v = Vec3::new(velocity[0], velocity[1], velocity[2]);
+        if let Some(d) = self.dropped.iter_mut().find(|d| d.id == id as u32) {
+            d.velocity = v;
+        } else if let Some(f) = self.falling.iter_mut().find(|f| f.id == id as u32) {
+            f.velocity = v;
+        } else if let Some(p) = self
+            .remote
+            .as_mut()
+            .and_then(|r| r.pending_items.get_mut(&id))
+        {
+            p.1 = v;
+        }
+    }
     fn apply_remote_health(&mut self) {
         let Some((health, food, saturation)) = self.remote.as_ref().map(|r| r.health) else {
             return;
@@ -2994,6 +3152,8 @@ impl Game<'_> {
             }
             None => {
                 let mut player = PlayerMotion::new(self.motion, position)?;
+                // Player.tick derives noPhysics from the current game mode.
+                player.spectator = self.spectator();
                 player.velocity = delta;
                 self.player = Some(player);
                 self.pad.player_replaced();
@@ -3028,6 +3188,8 @@ impl Game<'_> {
     /// One client tick while connected (Minecraft.tick with a ClientLevel).
     pub(super) fn tick_remote(&mut self) -> Result<()> {
         self.tick_remote_level()?;
+        // Client mods tick on any server, single player's own included.
+        self.tick_mods();
         // Minecraft.tick sends this even when the player cannot tick yet,
         // including while waiting for chunks. Keep it outside early returns.
         if self.remote.as_ref().is_some_and(|r| r.joined) {
@@ -3053,6 +3215,7 @@ impl Game<'_> {
         // Minecraft.tick: TickRateManager.tick; ClientLevel.tickTime advances
         // the time only while the level runs normally.
         let running = self.clock.world_runs();
+        self.boss_overlay.tick_darken(running);
         if running {
             self.world.game_time += 1;
             self.remote_clock_tick();
@@ -3081,7 +3244,7 @@ impl Game<'_> {
         self.sleep_timer = super::tick_sleep_timer(self.sleep_timer, self.sleeping.is_some());
         // Gui.tick: the titles, the action bar and the held item's name.
         self.tick_hud();
-        let ghast_collisions = self.happy_ghast_player_collisions();
+        let entity_collisions = self.player_entity_collisions();
         let pushed = self.remote_pushes();
         let Some(player) = self.player.as_mut() else {
             return Ok(());
@@ -3136,6 +3299,9 @@ impl Game<'_> {
             | u8::from(keys.sprint) << 6;
         // A passenger moves with its vehicle (Entity.rideTick), not by itself.
         let riding = self.screen != Screen::Dead && self.remote_ride(keys);
+        // The server sends no passenger's position: they sit where their
+        // vehicles are now.
+        self.position_riders();
         let Some(player) = self.player.as_mut() else {
             return Ok(());
         };
@@ -3163,9 +3329,10 @@ impl Game<'_> {
             );
             player.velocity = Vec3::ZERO;
         } else if !dead && !riding {
+            player.client_side = true;
             player.velocity = player.velocity.add_vector(pushed);
             MotionWorld {
-                entities: &ghast_collisions,
+                entities: &entity_collisions,
                 player,
                 scene: &mut self.world,
                 assets: &self.pack.assets,
@@ -3206,7 +3373,7 @@ impl Game<'_> {
                 _ => {}
             }
         }
-        // The server owns health and hunger: undo local food/fall changes.
+        // The server owns health and hunger.
         self.apply_remote_health();
         self.tick_avatar(before, false);
         // The player's own model (third person, the inventory's preview).
@@ -3246,9 +3413,10 @@ impl Game<'_> {
         player.flying_speed = a.flying_speed;
     }
     /// The local player's share of every touching entity's
-    /// `LivingEntity.pushEntities`: on a client `EntitySelector.pushableBy`
-    /// lets entities push only the local player, so the server never sends
-    /// these pushes. `doPush(player)` is `player.push(entity)`.
+    /// `LivingEntity.pushEntities`, and of the boats' pushes: on a client
+    /// `EntitySelector.pushableBy` lets entities push only the local player,
+    /// so the server never sends these pushes. `doPush(player)` is
+    /// `player.push(entity)`.
     fn remote_pushes(&self) -> Vec3 {
         let (Some(p), Some(r)) = (self.player.as_ref(), self.remote.as_ref()) else {
             return Vec3::ZERO;
@@ -3307,11 +3475,54 @@ impl Game<'_> {
             za *= f64::from(0.05_f32);
             push = Vec3::new(push.x - xa, push.y, push.z - za);
         }
+        // AbstractBoat.push(player) from the boat's own tick (its box grown
+        // by 0.2 sideways) and from the player's pushEntities (its box).
+        let player_team = teams.of(Who::Player);
+        let area = Vec3::new(f64::from(0.2_f32), f64::from(-0.01_f32), f64::from(0.2_f32));
+        for b in self.boats.iter().filter(|b| self.riding != Some(b.id)) {
+            let bb = b.bounds();
+            let times = usize::from(
+                bounds.intersects(bb.inflate(area))
+                    && horizon_client::scoreboard::pushable_by(None, player_team, true),
+            ) + usize::from(
+                bounds.intersects(bb)
+                    && horizon_client::scoreboard::pushable_by(player_team, None, true),
+            );
+            if times > 0
+                && super::boat_passengers::boat_pushes(bb, bounds, false)
+                && let Some(v) = super::boat_passengers::push_impulse(b.position, p.position)
+            {
+                push = push.add_vector(v.scale(times as f64));
+            }
+        }
         push
     }
     /// ClientLevel.tickEntities; a frozen level only ticks the players
     /// (`TickRateManager.isEntityFrozen`).
     fn tick_remote_entities(&mut self, running: bool) {
+        if running {
+            self.tick_text_displays();
+        }
+        // EntityFluidInteraction.update for the entities this window only displays: the
+        // server never sends the fluid contact, and the renderers read it (cod, salmon and
+        // tropical fish lie on their side without `in_water`, #1591).
+        // A frozen level ticks only the players, as below.
+        let fluids: Vec<_> = {
+            let w = self.mob_world_base(&[]);
+            let players = self.remote.as_ref().map(|r| &r.level_players);
+            self.mobs
+                .iter()
+                .map(|m| {
+                    (running || players.is_some_and(|p| p.contains_key(&(m.id as i32))))
+                        .then(|| w.fluids(m.bounds(), m.eye_y()))
+                })
+                .collect()
+        };
+        for (m, fluids) in self.mobs.iter_mut().zip(fluids) {
+            if let Some(fluids) = fluids {
+                m.fluids = fluids;
+            }
+        }
         let Some(r) = self.remote.as_mut() else {
             return;
         };
@@ -3414,20 +3625,12 @@ impl Game<'_> {
                 l.steps -= 1;
             }
         }
+        // ItemEntity.tick runs on a client too: gravity, collisions and
+        // friction move the item between the server's updates (every 20
+        // ticks), and only the server removes it.
+        let (world, facts, collision) = (&self.world, self.res.facts(), self.collision);
         for d in self.dropped.iter_mut().filter(|_| running) {
-            d.previous = d.position;
-            d.age += 1;
-            if let Some(l) = lerps.get_mut(&(d.id as i32))
-                && l.steps > 0
-            {
-                let n = f64::from(l.steps);
-                d.position = Vec3::new(
-                    d.position.x + (l.target[0] - d.position.x) / n,
-                    d.position.y + (l.target[1] - d.position.y) / n,
-                    d.position.z + (l.target[2] - d.position.z) / n,
-                );
-                l.steps -= 1;
-            }
+            d.tick(world, facts, collision, false);
         }
         head_lerps.retain(|_, (_, steps)| *steps > 0);
         for (item, ticks, at, eye, pitch, yaw) in using {
@@ -3776,7 +3979,7 @@ impl Game<'_> {
         let sneaking = self.keys.contains(&KeyCode::ShiftLeft);
         // A boat, minecart, item frame, armor stand or painting nearer than
         // any mob: the server uses it (AbstractBoat.interact boards it).
-        if let Some(hit) = self.remote_object_hit()
+        if let Some(hit) = self.remote_object_hit(false)
             && self.mob_hit().is_none_or(|(_, d)| hit.distance < d)
             && self.before_block(hit.distance)
         {
@@ -3862,11 +4065,17 @@ impl Game<'_> {
                 self.predict_item_on_block(stack, &hit);
             }
             if held_block {
-                if reacts
-                    || held
-                        .as_ref()
-                        .is_some_and(|stack| self.remote_can_place(&hit, stack))
-                {
+                let placed = if reacts {
+                    None
+                } else {
+                    held.as_ref()
+                        .and_then(|stack| self.remote_can_place(&hit, stack))
+                };
+                if let Some(placed) = &placed {
+                    self.predict_place(placed, seq);
+                    self.with_hand(hand, Game::consume_held);
+                }
+                if reacts || placed.is_some() {
                     self.with_hand(hand, Game::swing_arm);
                 }
                 // BlockItem.place returns FAIL when placement is rejected:
@@ -3926,18 +4135,7 @@ impl Game<'_> {
         {
             return;
         }
-        for &(p, state) in changes {
-            let pos = [p.x, p.y, p.z];
-            let before = self.world.block(p.x, p.y, p.z);
-            // BlockStatePredictionHandler.retainKnownServerState.
-            if let Some(r) = self.remote.as_mut() {
-                r.predictions
-                    .entry(pos)
-                    .and_modify(|e| e.0 = seq)
-                    .or_insert((seq, before.0 as i32));
-            }
-            self.set_block(pos, state.0 as i32);
-        }
+        self.predict_blocks(changes, seq);
         // `level.playSound(player, ...)`: the clicker hears it from its own use; the
         // server sends it to the others only.
         for (pos, sound, volume, pitch) in sounds {
@@ -3997,12 +4195,45 @@ impl Game<'_> {
         })
     }
 
-    /// Run BlockItem.place on a disposable level before predicting its swing.
-    /// The real level supplies collision shapes and building-blocking entities;
-    /// block writes, random draws, scheduled ticks and events stay in the preview.
-    fn remote_can_place(&mut self, hit: &super::Hit, stack: &ItemStack) -> bool {
+    /// MultiPlayerGameMode.useItemOn inside startPrediction, for a block item:
+    /// the blocks `BlockItem.place` set at `pos` are placed on this client's
+    /// level at once, so the next click of a fast bridge aims at them rather
+    /// than past them (the server would refuse it). Its place sound is the
+    /// placer's own (`playSound(player, ...)`: the server sends it to the
+    /// others only).
+    fn predict_place(&mut self, (pos, changes): &DryPlace, seq: i32) {
+        let ticks = self.ticks;
+        if let Some(r) = self.remote.as_mut() {
+            // set_block plays the place sound of the block at `placing`.
+            r.placing = Some(([pos.x, pos.y, pos.z], ticks));
+        }
+        self.predict_blocks(changes, seq);
+    }
+    /// The blocks a use changed, set on this client's level and kept as
+    /// predicted under the use's sequence until the server acknowledges it
+    /// (`BlockStatePredictionHandler.retainKnownServerState`): a use the
+    /// server refused goes back.
+    fn predict_blocks(&mut self, changes: &DryChanges, seq: i32) {
+        for &(p, state) in changes {
+            let pos = [p.x, p.y, p.z];
+            let before = self.world.block(p.x, p.y, p.z);
+            if let Some(r) = self.remote.as_mut() {
+                r.predictions
+                    .entry(pos)
+                    .and_modify(|e| e.0 = seq)
+                    .or_insert((seq, before.0 as i32));
+            }
+            self.set_block(pos, state.0 as i32);
+        }
+    }
+
+    /// Run BlockItem.place on a disposable level: where it placed and the
+    /// blocks it set. The real level supplies collision shapes and
+    /// building-blocking entities; random draws, scheduled ticks and events
+    /// stay in the preview.
+    fn remote_can_place(&mut self, hit: &super::Hit, stack: &ItemStack) -> Option<DryPlace> {
         if !self.may_build() {
-            return false;
+            return None;
         }
         let ctx = horizon_world::level::PlaceContext {
             clicked_pos: horizon_core::position::BlockPos::new(hit.pos[0], hit.pos[1], hit.pos[2]),
@@ -4017,14 +4248,16 @@ impl Game<'_> {
         };
         self.with_level(|b, level, _| {
             let mut level = DryLevel::new(level);
-            matches!(
-                b.place_block(
-                    &mut level,
-                    &mut horizon_world::level::Ticks::default(),
-                    &ctx
-                ),
-                horizon_world::level::PlaceOutcome::Placed { .. }
-            )
+            match b.place_block(
+                &mut level,
+                &mut horizon_world::level::Ticks::default(),
+                &ctx,
+            ) {
+                horizon_world::level::PlaceOutcome::Placed { pos, .. } => {
+                    Some((pos, level.changed.into_iter().collect()))
+                }
+                horizon_world::level::PlaceOutcome::Failed => None,
+            }
         })
     }
 
@@ -4126,11 +4359,13 @@ impl Game<'_> {
             return;
         };
         let stack = self.stack_in(slot).cloned();
+        // Another hotbar slot picked: LivingEntity.updatingUsingItem sees a
+        // different stack in the hand. The off hand keeps its item.
+        let in_hand = slot == self.selected || slot == super::shield::OFFHAND_SLOT;
         // A drawn bow, a charging crossbow, a raised shield...: held until
-        // the button lets go (or another slot is picked).
+        // the button lets go.
         if stack.as_ref().is_some_and(|s| self.held_until_released(s)) {
-            self.using = (slot == self.selected || slot == super::shield::OFFHAND_SLOT)
-                .then_some((slot, ticks + 1));
+            self.using = in_hand.then_some((slot, ticks + 1));
             return;
         }
         let consumable = stack
@@ -4144,7 +4379,7 @@ impl Game<'_> {
         // Button release belongs to the next handleKeybinds phase, which
         // sends RELEASE_USE_ITEM. Do not silently clear a use begun by a
         // quick press/release between ticks.
-        if slot != self.selected {
+        if !in_hand {
             self.using = None;
             return;
         }
@@ -4253,12 +4488,12 @@ impl Game<'_> {
                 id: self.creatures.projectiles[i].id as i32,
             }));
             self.reset_attack_strength();
-        } else if let Some(hit) = self.remote_object_hit()
+        } else if let Some(hit) = self.remote_object_hit(true)
             && self.mob_hit().is_none_or(|(_, d)| hit.distance < d)
             && self.before_block(hit.distance)
         {
             // VehicleEntity.hurtServer, ItemFrame and ArmorStand hurtServer,
-            // a painting broken: the server decides.
+            // a painting broken or an EndCrystal hurtServer: the server decides.
             self.send(S::Attack(play::Attack { id: hit.id }));
             self.reset_attack_strength();
         } else if let Some((i, distance)) = self.mob_hit()
@@ -4318,8 +4553,7 @@ impl Game<'_> {
     /// Keys with a multiplayer meaning; returns true when consumed.
     pub(super) fn remote_key(&mut self, key: KeyCode) -> Result<bool> {
         if self.screen != Screen::Playing {
-            if key == KeyCode::KeyE && self.screen == Screen::Inventory
-                || key == KeyCode::Escape && self.screen == Screen::Inventory
+            if (key == KeyCode::KeyE || key == KeyCode::Escape) && self.screen == Screen::Inventory
             {
                 self.remote_close_container();
                 self.screen = Screen::Playing;
@@ -4466,12 +4700,10 @@ impl Game<'_> {
         for &(slot, button, input) in ops {
             let slot = match slot {
                 None => -999,
-                Some(internal) => {
-                    match (0..64).find(|&s| Self::menu_slot(&menu, s) == Some(internal)) {
-                        Some(s) => s as i16,
-                        None => return false,
-                    }
-                }
+                Some(internal) => match Self::menu_slot_index(&menu, internal) {
+                    Some(s) => s as i16,
+                    None => return false,
+                },
             };
             clicks.push((slot, button, input));
         }
@@ -4540,7 +4772,7 @@ impl Game<'_> {
     /// such slot.
     pub(super) fn remote_slot_click(&mut self, internal: usize, button: i8, input: i32) -> bool {
         let (container, menu) = self.remote_menu();
-        let slot = (0..64).find(|&s| Self::menu_slot(&menu, s) == Some(internal));
+        let slot = Self::menu_slot_index(&menu, internal);
         let Some(slot) = slot else { return false };
         let carried = self.to_network(&self.carried).map(|s| Hashed::of(&s));
         let state = self.remote.as_ref().map_or(0, |r| r.state_id);
@@ -4616,6 +4848,11 @@ impl Game<'_> {
         self.mount_menu_reset();
         // The client's menu has no level access: what it holds is the server's.
         self.station = None;
+        // AbstractContainerMenu.removed: the server gives the grid and the
+        // carried stack back to the inventory and syncs it; the copies here
+        // are stale the moment the window closes.
+        self.craft_grid.fill(None);
+        self.carried = None;
         self.craft_size = 2;
         if let Some(key) = self.container.take() {
             // Server containers stay renderable but lose their copied slots.
@@ -4975,6 +5212,8 @@ impl Game<'_> {
                 .collect::<Vec<_>>(),
             // The player's own model exists (third person and the inventory draw it).
             "player_model": self.player_model.is_some(),
+            "text_display_vertices": self.text_display_vertices,
+            "text_displays": self.text_displays.len(),
             "health": r.health.0,
             "food": r.health.1,
             "decode_errors": r.decode_errors,
@@ -5074,11 +5313,12 @@ type DrySound = (
     f32,
     f32,
 );
+/// The blocks a use on the dry level set.
+type DryChanges = Vec<(horizon_core::position::BlockPos, BlockStateId)>;
 /// What a use on the dry level changed, and the sounds it played.
-type DryUse = (
-    Vec<(horizon_core::position::BlockPos, BlockStateId)>,
-    Vec<DrySound>,
-);
+type DryUse = (DryChanges, Vec<DrySound>);
+/// Where `BlockItem.place` on the dry level placed, and the blocks it set.
+type DryPlace = (horizon_core::position::BlockPos, DryChanges);
 
 /// The blocks a guest's hand flips that its use predicts (and hears at once): a wooden or
 /// copper door, trapdoor or fence gate, a lever or a button. An iron door or trapdoor has
@@ -5267,6 +5507,10 @@ impl horizon_client::interaction_input::InteractionWorld for RemoteInputWorld<'_
 }
 
 impl Remote {
+    /// Players in the server's player list, this one included.
+    pub(super) fn player_count(&self) -> usize {
+        self.players.len()
+    }
     /// The local player's profile UUID.
     pub(super) fn profile(&self) -> u128 {
         self.profile
@@ -5399,4 +5643,28 @@ mod tests {
         }
         assert_eq!(Game::menu_slot("inventory", 46), None);
     }
+
+    #[test]
+    fn remote_clicks_find_slots_past_the_old_large_chest_cutoff() {
+        for (menu, internal, index) in [
+            ("minecraft:generic_9x6", 18, 63),
+            ("minecraft:generic_9x6", 19, 64),
+            ("minecraft:generic_9x6", 0, 81),
+            ("minecraft:generic_9x6", 8, 89),
+            ("minecraft:generic_9x6", 353, 53),
+            ("minecraft:generic_9x5", 8, 80),
+            ("minecraft:generic_9x4", 8, 71),
+            ("minecraft:generic_9x3", 8, 62),
+            ("inventory", 504, 45),
+        ] {
+            assert_eq!(
+                Game::menu_slot_index(menu, internal),
+                Some(index),
+                "{menu}, game slot {internal}"
+            );
+        }
+        assert_eq!(Game::menu_slot_index("minecraft:generic_9x6", 354), None);
+        assert_eq!(Game::menu_slot_index("minecraft:generic_9x6", 504), None);
+        assert_eq!(Game::menu_slot_index("unknown", 0), None);
+    }
 }

crates/horizon-client/src/game/remote_mob_data.rs

@@ -3,12 +3,15 @@
 //! `onSyncedDataUpdated`): what a client draws from it rather than from its
 //! own simulation, which a client of a server doesn't run.
 use super::Game;
+use horizon_client::mobs::render::{PROFESSIONS, VILLAGER_TYPES};
 use horizon_client::mobs::{Mob, Species, tame};
 use horizon_protocol::entity_data::Value;
+use horizon_protocol::registry::Builtin;
 
 /// The values `apply` takes from one SetEntityData packet, by vanilla's entry
 /// indices (Entity 0..=7, LivingEntity 8..=14, Mob 15, then the subclasses).
-fn apply(m: &mut Mob, values: &[(u8, i32, Value)]) {
+/// `builtin` names the ids of built-in registries.
+fn apply(m: &mut Mob, values: &[(u8, i32, Value)], builtin: &Builtin) {
     let species = m.species();
     let baby = super::lan::baby_index(&m.kind.id);
     for (index, _, value) in values {
@@ -42,16 +45,45 @@ fn apply(m: &mut Mob, values: &[(u8, i32, Value)]) {
             (Species::Slime | Species::MagmaCube, 18, Value::Int(size)) => {
                 m.extra.size = (*size).clamp(1, 127);
             }
+            // Villager.DATA_VILLAGER_DATA and ZombieVillager's (after
+            // Zombie's three): what VillagerProfessionLayer draws.
+            (Species::Villager, 19, Value::Ids(data))
+            | (Species::ZombieVillager, 20, Value::Ids(data)) => villager_data(m, data, builtin),
             _ => {}
         }
     }
 }
 
+/// VillagerData as the network sends it: the type and the profession by
+/// their built-in registry ids, then the level.
+fn villager_data(m: &mut Mob, data: &[i32], builtin: &Builtin) {
+    let &[kind, profession, level] = data else {
+        return;
+    };
+    let index = |registry: &str, id: i32, names: &[&str]| {
+        let name = builtin
+            .get(registry)?
+            .name(id)?
+            .strip_prefix("minecraft:")?;
+        names.iter().position(|n| *n == name).map(|i| i as u8)
+    };
+    if let Some(t) = index("minecraft:villager_type", kind, &VILLAGER_TYPES) {
+        m.extra.variant = t;
+    }
+    if let Some(p) = index("minecraft:villager_profession", profession, &PROFESSIONS) {
+        m.extra.variant2 = p;
+    }
+    m.extra.variant3 = level.clamp(0, i32::from(u8::MAX)) as u8;
+}
+
 impl Game<'_> {
     /// SetEntityData for a mob of the server's.
     pub(super) fn remote_mob_data(&mut self, id: i32, values: &[(u8, i32, Value)]) {
+        let Some(r) = &self.remote else {
+            return;
+        };
         if let Some(m) = self.mobs.iter_mut().find(|m| m.id == id as u32) {
-            apply(m, values);
+            apply(m, values, &r.builtin);
         }
     }
 }
@@ -72,11 +104,23 @@ mod tests {
 
     /// A mob of the prepared resources' type `kind`, as a client spawns it
     /// (None without the resources).
-    fn mob(kind: &str) -> Option<Mob> {
-        let root = std::path::Path::new(env!("CARGO_MANIFEST_DIR"))
+    fn root() -> std::path::PathBuf {
+        std::path::Path::new(env!("CARGO_MANIFEST_DIR"))
             .join("../../.local/horizon-client")
-            .join(horizon_core::VANILLA_VERSION);
-        let types = horizon_client::mobs::MobTypes::load(&root).ok()?;
+            .join(horizon_core::VANILLA_VERSION)
+    }
+
+    /// The prepared resources' built-in registries (empty without them).
+    fn builtin() -> Builtin {
+        Builtin::load(&root().join("registries.json")).unwrap_or_default()
+    }
+
+    fn apply(m: &mut Mob, values: &[(u8, i32, Value)]) {
+        super::apply(m, values, &builtin());
+    }
+
+    fn mob(kind: &str) -> Option<Mob> {
+        let types = horizon_client::mobs::MobTypes::load(&root()).ok()?;
         let t = std::sync::Arc::new(types.types.get(kind)?.clone());
         let mut m = Mob::new(1, t, horizon_core::geometry::Vec3::ZERO, 0.0);
         client_defaults(&mut m);
@@ -133,4 +177,45 @@ mod tests {
         apply(&mut m, &[(0, s::BYTE, Value::Byte(0))]);
         assert_eq!(m.fire_ticks, 0);
     }
+
+    #[test]
+    fn a_villager_takes_its_type_profession_and_level() {
+        let Some(mut m) = mob("minecraft:villager") else {
+            return;
+        };
+        let registries = builtin();
+        let id = |registry: &str, name: &str| registries.get(registry)?.id(name);
+        let (Some(desert), Some(farmer), Some(librarian)) = (
+            id("minecraft:villager_type", "minecraft:desert"),
+            id("minecraft:villager_profession", "minecraft:farmer"),
+            id("minecraft:villager_profession", "minecraft:librarian"),
+        ) else {
+            return;
+        };
+        let name = |m: &Mob| {
+            (
+                VILLAGER_TYPES[m.extra.variant as usize],
+                PROFESSIONS[m.extra.variant2 as usize],
+                m.extra.variant3,
+            )
+        };
+        apply(
+            &mut m,
+            &[(19, s::VILLAGER_DATA, Value::Ids(vec![desert, farmer, 2]))],
+        );
+        assert_eq!(name(&m), ("desert", "farmer", 2));
+        // A job taken later: only the profession and the level change.
+        apply(
+            &mut m,
+            &[(19, s::VILLAGER_DATA, Value::Ids(vec![desert, librarian, 5]))],
+        );
+        assert_eq!(name(&m), ("desert", "librarian", 5));
+        // A zombie villager's data comes after Zombie's three entries.
+        let mut z = mob("minecraft:zombie_villager").unwrap();
+        apply(
+            &mut z,
+            &[(20, s::VILLAGER_DATA, Value::Ids(vec![desert, farmer, 3]))],
+        );
+        assert_eq!(name(&z), ("desert", "farmer", 3));
+    }
 }

crates/horizon-client/src/game/remote_objects.rs

@@ -24,7 +24,12 @@ impl Game<'_> {
         let at = Vec3::new(position[0], position[1], position[2]);
         let block = position.map(|v| v.floor() as i32);
         self.remove_remote_object(id);
-        if let Some(cart) = super::minecarts::CartKind::from_id(kind) {
+        if kind == "minecraft:text_display" {
+            self.text_displays.insert(
+                id as i32,
+                super::text_displays::RemoteTextDisplay::new(position, yaw),
+            );
+        } else if let Some(cart) = super::minecarts::CartKind::from_id(kind) {
             let mut c = super::minecarts::Minecart::new(id, cart, at);
             c.yaw = yaw;
             c.previous_yaw = yaw;
@@ -93,6 +98,10 @@ impl Game<'_> {
 
     /// `handleSetEntityData` for an object: what changes how it looks.
     pub(super) fn remote_object_data(&mut self, id: i32, values: &[(u8, i32, Value)]) {
+        if let Some(display) = self.text_displays.get_mut(&id) {
+            display.metadata(values);
+            return;
+        }
         let id = id as u32;
         for (index, _, value) in values {
             if self.item_frames.iter().any(|f| f.id == id) {
@@ -273,6 +282,7 @@ impl Game<'_> {
 
     /// Every object a server sent (a new connection, level or dimension).
     pub(super) fn clear_remote_objects(&mut self) {
+        self.text_displays.clear();
         self.carts.clear();
         self.boats.clear();
         self.armor_stands.clear();
@@ -281,6 +291,7 @@ impl Game<'_> {
     }
 
     pub(super) fn remove_remote_object(&mut self, id: u32) {
+        self.text_displays.remove(&(id as i32));
         self.carts.retain(|c| c.id != id);
         self.boats.retain(|b| b.id != id);
         self.armor_stands.retain(|a| a.id != id);

crates/horizon-client/src/game/remote_projectiles.rs

@@ -2,7 +2,7 @@
 //! end crystals on a server's client (`ClientPacketListener.handleAddEntity`
 //! and `handleSetEntityData`): the server simulates them, the client draws
 //! them where it says and interpolates their moves.
-use super::{FallingBlock, Game};
+use super::{FallStep, FallingBlock, Game};
 use horizon_client::projectiles::{Projectile, ProjectileKind};
 use horizon_core::{geometry::Vec3, position::BlockPos};
 use horizon_protocol::entity_data::Value;
@@ -24,6 +24,14 @@ fn projectile_kind(kind: &str) -> Option<ProjectileKind> {
         "minecraft:llama_spit" => ProjectileKind::LlamaSpit,
         "minecraft:wind_charge" => ProjectileKind::WindCharge,
         "minecraft:breeze_wind_charge" => ProjectileKind::BreezeWindCharge,
+        // Homing state stays on the server; the client interpolates its positions.
+        "minecraft:shulker_bullet" => ProjectileKind::ShulkerBullet {
+            target: horizon_client::mobs::Who::Player,
+            dir: None,
+            steps: 0,
+            delta: [0.0; 3],
+            seed: 0,
+        },
         "minecraft:wither_skull" => ProjectileKind::WitherSkull { dangerous: false },
         _ => return None,
     })
@@ -185,11 +193,17 @@ impl Game<'_> {
             t.previous = t.position;
             t.position = step(t.id, t.position);
         }
-        for f in &mut self.falling {
-            f.previous = f.position;
-            f.age += 1;
-            f.position = step(f.id, f.position);
+        // FallingBlockEntity.tick runs on a client too: the block falls by
+        // itself between the server's updates (every 20 ticks), then waits
+        // where it lands for the server to place it and remove it.
+        let mut falling = std::mem::take(&mut self.falling);
+        for f in &mut falling {
+            if let Ok(FallStep::Landed(_)) = self.fall_step(f, false) {
+                // Block.updateEntityMovementAfterFallOn, then the air drag.
+                f.velocity = Vec3::new(f.velocity.x * 0.98, 0.0, f.velocity.z * 0.98);
+            }
         }
+        self.falling = falling;
         for p in &mut self.creatures.projectiles {
             p.previous = p.position;
             p.age += 1;

crates/horizon-client/src/game/remote_vehicles.rs

@@ -9,8 +9,8 @@
 //! server (`LocalPlayer.tick`: `ServerboundMoveVehiclePacket`,
 //! `AbstractBoat.tick`: `ServerboundPaddleBoatPacket`). A minecart moves on
 //! the server with the rider's input, and the rider sits in it.
-use super::{Game, Keys, view_vector};
-use horizon_core::geometry::Vec3;
+use super::{Game, Keys, ray_box, view_vector};
+use horizon_core::geometry::{Aabb, Vec3};
 use horizon_protocol::packets::play::{self, Serverbound as S};
 
 /// An object under the crosshair: its entity id, how far along the view it
@@ -24,8 +24,8 @@ pub(super) struct ObjectHit {
 
 impl Game<'_> {
     /// The nearest boat, minecart, item frame, armor stand or painting the
-    /// view hits within reach.
-    pub(super) fn remote_object_hit(&self) -> Option<ObjectHit> {
+    /// view hits within reach; also End crystals when attacking.
+    pub(super) fn remote_object_hit(&self, attacking: bool) -> Option<ObjectHit> {
         let eye = self.eye_position()?;
         let dir = view_vector(self.yaw, self.pitch);
         let at = |d: f64| {
@@ -64,6 +64,22 @@ impl Game<'_> {
             let p = self.carts[i].position;
             hits.push((self.carts[i].id as i32, d, [p.x, p.y, p.z]));
         }
+        if attacking {
+            // EndCrystal.isPickable: its 2 x 2 box, with the server's entity
+            // id, not special_targets' local projectile target id.
+            // Entity.interact passes on a crystal, so right clicks use the item.
+            let reach = if self.creative { 5.0 } else { 3.0 };
+            for c in self.crystals.iter().filter(|c| c.id != 0) {
+                let p = c.position;
+                let bounds = Aabb::new(
+                    Vec3::new(p.x - 1.0, p.y, p.z - 1.0),
+                    Vec3::new(p.x + 1.0, p.y + 2.0, p.z + 1.0),
+                );
+                if let Some(d) = ray_box(eye, dir, reach, bounds) {
+                    hits.push((c.id as i32, d, [p.x, p.y, p.z]));
+                }
+            }
+        }
         let (id, distance, origin) = hits.into_iter().min_by(|a, b| a.1.total_cmp(&b.1))?;
         let point = at(distance);
         Some(ObjectHit {
@@ -88,8 +104,10 @@ impl Game<'_> {
         for m in &mut self.mobs {
             if m.extra.mount == Some(vehicle_id) && !passengers.contains(&(m.id as i32)) {
                 m.extra.mount = None;
+                m.extra.passenger = false;
             } else if passengers.contains(&(m.id as i32)) {
                 m.extra.mount = Some(vehicle_id);
+                m.extra.passenger = true;
             }
         }
         if passengers.contains(&me) {
@@ -129,17 +147,20 @@ impl Game<'_> {
             self.yaw += b.delta_rotation;
             let delta = (self.yaw - b.yaw + 180.0).rem_euclid(360.0) - 180.0;
             self.yaw += delta.clamp(-105.0, 105.0) - delta;
-            let seat = b.position;
             self.boats[i] = b;
-            Some(seat)
+            // In front of a mob that shares the boat.
+            Some(self.player_boat_seat(i))
         } else {
             // A minecart: the server moves it, the rider sits in it.
-            self.carts.iter().find(|c| c.id == id).map(|c| c.position)
+            self.carts.iter().find(|c| c.id == id).map(|c| {
+                c.position
+                    .add_vector(Vec3::new(0.0, super::minecarts::SEAT, 0.0))
+            })
         };
         if let Some(p) = self.player.as_mut() {
             self.previous_position = p.position;
             if let Some(v) = seat {
-                p.position = Vec3::new(v.x, v.y + super::boats::SEAT, v.z);
+                p.position = v;
             }
             p.velocity = Vec3::ZERO;
             p.fall_distance = 0.0;

crates/horizon-client/src/game/render_control.rs

@@ -13,6 +13,7 @@ pub const HELP: &[&str] = &[
     "signedit X Y Z [front|back]    open the sign editor for the sign at X Y Z",
     "section-draws [flat|indirect]  how terrain sections are drawn (A/B checks); replies the mode",
     "section-cull [on|off]          occlusion culling of solid sections (A/B checks); replies the mode",
+    "section-sides [on|off]         leave out solid quads facing away from the eye (A/B checks); replies the mode",
 ];
 
 impl Game<'_> {

crates/horizon-client/src/game/render_tick.rs

@@ -100,49 +100,13 @@ impl Game<'_> {
                 skybox: self.dim == Dim::Overworld,
                 blindness: None,
                 darkness: self.darkness_fog(),
-                boss_world_fog: self.dragon_bar_shown(),
+                darken_world: self
+                    .boss_overlay
+                    .darken_amount(self.clock.fraction() as f32),
+                boss_world_fog: self.boss_overlay.should_create_world_fog(),
             },
         )
     }
-    /// What a shader pack's `Frame` uniform reads of the game this frame.
-    pub(super) fn shader_inputs(
-        &self,
-        camera: glam::DVec3,
-        partial_tick: f32,
-    ) -> horizon_client::gfx::ShaderInputs {
-        let (rain, thunder) = if self.dim == Dim::Overworld {
-            self.world.weather.levels(self.clock.fraction() as f32)
-        } else {
-            (0.0, 0.0)
-        };
-        let at = [camera.x, camera.y, camera.z];
-        let day = self.world.day_time;
-        let has_sky_light = self.dim == Dim::Overworld;
-        // CommonUniforms.getEyeBrightness: the camera entity's eye block.
-        let eye = self.eye_position().unwrap_or(at).map(|v| v.floor() as i32);
-        let light = self.world.light(eye[0], eye[1], eye[2]);
-        let eye_light = [light & 15, if has_sky_light { light >> 4 } else { 0 }];
-        horizon_client::gfx::ShaderInputs {
-            rain,
-            thunder,
-            submerged: match fog_type(&self.world, self.res.facts(), at, self.forward()) {
-                FogType::Atmospheric => 0,
-                FogType::Water => 1,
-                FogType::Lava => 2,
-                FogType::PowderSnow => 3,
-            },
-            dimension: match self.dim {
-                Dim::Overworld => 0,
-                Dim::Nether => -1,
-                Dim::End => 1,
-            },
-            has_sky_light,
-            moon_phase: day.div_euclid(24_000).rem_euclid(8) as u8,
-            day_fraction: (day.rem_euclid(24_000) as f32 + partial_tick) / 24_000.0,
-            partial_tick,
-            eye_light,
-        }
-    }
     /// `SkyRenderer.shouldRenderDarkDisc`: eye below the horizon (y 63) and not under water.
     pub(super) fn dark_disc(&self, camera: glam::DVec3) -> bool {
         camera.y < 63.0

crates/horizon-client/src/game/scoreboard.rs

@@ -180,7 +180,7 @@ impl Game<'_> {
             | Target::Cart(id)
             | Target::Other(id) => self.persist.raw.get(&id),
             Target::Player => self.level.player_extra.as_ref(),
-            Target::Guest(_) | Target::Orb(_) | Target::Arrow(_) => None,
+            Target::Guest(_) | Target::Orb(_) | Target::Projectile(_) => None,
         };
         match raw.and_then(|r| r.get("Tags")) {
             Some(Tag::List(l)) => l

crates/horizon-client/src/game/server_packs.rs

@@ -0,0 +1,559 @@
+//! A server's resource packs bound to the game (`ClientCommonPacketListenerImpl.
+//! handleResourcePackPush` and `handleResourcePackPop`, its `PackConfirmScreen`,
+//! and `DownloadedPackSource` as `Minecraft` drives it): the prompt, the
+//! server list's setting, downloads into `downloads/`, and a resource reload
+//! with the server's packs on top of the player's own.
+use super::Game;
+use horizon_client::{
+    Result,
+    confirm_screen::Confirm,
+    hud::{HudAtlas, HudBatch},
+    java_text, multiplayer, packs,
+    scoreboard::{comp_text, tag_to_json},
+    server_packs::{Prompt, ServerPacks, action, download, parse_sha1, valid_url},
+    text::{Text, named_color},
+    toasts::SystemToast,
+    ui,
+};
+use horizon_core::jmath;
+use horizon_protocol::{packets::configuration::ResourcePackPush, servers};
+use std::{
+    path::PathBuf,
+    sync::mpsc::{Receiver, TryRecvError},
+};
+
+/// `ClientCommonPacketListenerImpl.PackConfirmScreen`: the packs it asks
+/// about, whether the last one is required, and the server's message.
+pub(super) struct PackPrompt {
+    requests: Vec<(u128, String, String)>,
+    required: bool,
+    prompt: Option<Text>,
+}
+impl PackPrompt {
+    fn texts(&self) -> (Text, Text, [Text; 2]) {
+        let t = |key: &str| Text::translate(key, &[]);
+        let (title, line2) = if self.required {
+            let yellow = named_color("yellow").unwrap_or(0xFFFF55);
+            (
+                t("multiplayer.requiredTexturePrompt.line1"),
+                t("multiplayer.requiredTexturePrompt.line2")
+                    .with_color(yellow)
+                    .bold(),
+            )
+        } else {
+            (
+                t("multiplayer.texturePrompt.line1"),
+                t("multiplayer.texturePrompt.line2"),
+            )
+        };
+        // preparePackPrompt.
+        let message = match &self.prompt {
+            Some(prompt) => Text::translate(
+                "multiplayer.texturePrompt.serverPrompt",
+                &[line2, prompt.clone()],
+            ),
+            None => line2,
+        };
+        let buttons = if self.required {
+            [t("gui.proceed"), t("menu.disconnect")]
+        } else {
+            [t("gui.yes"), t("gui.no")]
+        };
+        (title, message, buttons)
+    }
+    fn layout(&self, atlas: &HudAtlas, size: (f32, f32)) -> Confirm {
+        let (title, message, _) = self.texts();
+        Confirm::new(&atlas.font, size, &title, &message)
+    }
+}
+
+/// The game's `DownloadedPackSource`.
+#[derive(Default)]
+pub(super) struct ServerPackState {
+    packs: ServerPacks,
+    /// `downloads/` in the game folder, opened at the first download.
+    queue: Option<download::Queue>,
+    pub(super) prompt: Option<PackPrompt>,
+    /// The server list entry the setting is saved to (none: a direct join).
+    address: Option<String>,
+    /// The account the downloads are made for (the download headers).
+    user: (String, u128),
+    /// The packs loaded on top of the player's own, bottom first.
+    pub(super) active: Vec<packs::Pack>,
+    /// The download batches' notifiers, oldest first.
+    notifiers: Vec<PackNotifier>,
+}
+/// `DownloadedPackSource.createDownloadNotifier`: one batch's progress in its
+/// own `SystemToast`.
+struct PackNotifier {
+    progress: Receiver<download::Progress>,
+    total: usize,
+    /// `count`: the requests started.
+    count: usize,
+    /// `failCount`.
+    failed: usize,
+    /// `totalBytes`: the Content-Length of the request in flight.
+    size: Option<u64>,
+    /// The bytes it has written so far: none before the first response.
+    bytes: Option<u64>,
+    /// The last request has finished.
+    done: bool,
+    toast: Option<SystemToast>,
+}
+impl PackNotifier {
+    fn new(progress: Receiver<download::Progress>, total: usize) -> Self {
+        Self {
+            progress,
+            total,
+            count: 0,
+            failed: 0,
+            size: None,
+            bytes: None,
+            done: false,
+            toast: None,
+        }
+    }
+    /// The batch's events since the last call, with the toast updated once
+    /// for all of them. False once the batch has ended and its toast is gone.
+    fn poll(&mut self) -> bool {
+        let (mut changed, mut hide) = (false, false);
+        let ended = loop {
+            let event = match self.progress.try_recv() {
+                Ok(event) => event,
+                Err(e) => break e == TryRecvError::Disconnected,
+            };
+            changed |= match event {
+                download::Progress::RequestStart => {
+                    self.count += 1;
+                    true
+                }
+                download::Progress::DownloadStart(size) => {
+                    self.size = size;
+                    self.bytes = Some(0);
+                    true
+                }
+                download::Progress::Bytes(bytes) => {
+                    self.bytes = Some(bytes);
+                    true
+                }
+                download::Progress::RequestFinished(ok) => {
+                    self.failed += usize::from(!ok);
+                    self.done = self.count == self.total;
+                    // Every pack came: forceHide; else the failure title.
+                    hide |= self.done && self.failed == 0;
+                    self.done && self.failed > 0
+                }
+            };
+        };
+        if changed {
+            let (title, message) = self.text();
+            let (title, message) = (title.plain(), message.map(|m| m.plain()));
+            // SystemToast.addOrUpdate.
+            match &mut self.toast {
+                Some(toast) => toast.reset(title, message),
+                None => self.toast = Some(SystemToast::new(title, message)),
+            }
+        }
+        if hide && let Some(toast) = &mut self.toast {
+            toast.force_hide();
+        }
+        !ended || self.toast.is_some()
+    }
+    /// The toast's title and message.
+    fn text(&self) -> (Text, Option<Text>) {
+        if self.done && self.failed > 0 {
+            let failed = Text::tr("download.pack.failed", &[&self.failed, &self.total]);
+            return (failed, None);
+        }
+        let title = Text::tr("download.pack.title", &[&self.count, &self.total]);
+        let message = self.bytes.map(|bytes| match self.size {
+            Some(size) if size > 0 => {
+                Text::tr("download.pack.progress.percent", &[&(bytes * 100 / size)])
+            }
+            _ => Text::tr("download.pack.progress.bytes", &[&human_readable(bytes)]),
+        });
+        (title, message)
+    }
+}
+/// `com.mojang.realmsclient.Unit.humanReadable`, for
+/// `download.pack.progress.bytes`.
+fn human_readable(bytes: u64) -> String {
+    if bytes < 1024 {
+        return format!("{bytes} B");
+    }
+    let exp = (jmath::log(bytes as f64) / jmath::log(1024.0)) as i32;
+    let prefix = &"KMGTPE"[exp as usize - 1..exp as usize];
+    let value = bytes as f64 / 1024f64.powi(exp);
+    format!("{} {prefix}B", java_text::format_fixed(value, 1))
+}
+
+fn saves() -> PathBuf {
+    std::env::current_dir().unwrap_or_default().join("saves")
+}
+
+impl Game<'_> {
+    /// `ConnectScreen`: the server's setting decides what its packs do
+    /// (`configureForServerControl`); single player's own server takes them
+    /// all, quietly (`configureForLocalWorld`).
+    pub(super) fn server_packs_connect(&mut self, address: Option<&str>, user: (String, u128)) {
+        let state = &mut self.server_packs;
+        state.user = user;
+        state.prompt = None;
+        state.notifiers.clear();
+        let Some(address) = address else {
+            state.address = None;
+            state.packs.local_world();
+            return;
+        };
+        let file = multiplayer::servers_file(&saves());
+        let entry = servers::load(&file).into_iter().find(|s| s.ip == address);
+        let setting = entry.as_ref().and_then(|e| e.accept_textures);
+        state.address = entry.map(|e| e.ip);
+        state.packs.connect(Prompt::for_server(setting));
+    }
+    /// `Minecraft.clearDownloadedResourcePacks`: every server pack goes at once.
+    pub(super) fn server_packs_disconnect(&mut self) {
+        self.server_packs.prompt = None;
+        self.server_packs.notifiers.clear();
+        self.server_packs.packs.disconnect();
+        self.tick_server_packs();
+    }
+
+    /// `handleResourcePackPush`.
+    pub(super) fn handle_pack_push(&mut self, p: ResourcePackPush) {
+        if !valid_url(&p.url) {
+            self.send_pack_status(p.id, action::INVALID_URL);
+            return;
+        }
+        let setting = self.server_setting();
+        let prompt = Prompt::for_server(setting);
+        if prompt != Prompt::Pending && (!p.required || prompt != Prompt::Declined) {
+            self.server_packs
+                .packs
+                .push(p.id, &p.url, parse_sha1(&p.hash));
+            return;
+        }
+        // addOrUpdatePackPrompt: one prompt for every pack pushed before it is answered.
+        let text = p.prompt.as_ref().map(|t| comp_text(&tag_to_json(t)));
+        let state = &mut self.server_packs;
+        let open = state.prompt.get_or_insert(PackPrompt {
+            requests: Vec::new(),
+            required: p.required,
+            prompt: None,
+        });
+        open.requests.push((p.id, p.url, p.hash));
+        open.required = p.required;
+        open.prompt = text;
+        self.capture(false);
+    }
+    /// `handleResourcePackPop`: one pack, or all of them.
+    pub(super) fn handle_pack_pop(&mut self, id: Option<u128>) {
+        match id {
+            Some(id) => self.server_packs.packs.pop(id),
+            None => self.server_packs.packs.pop_all(),
+        }
+    }
+    /// The joined server's entry in the server list: its `acceptTextures`.
+    fn server_setting(&self) -> Option<bool> {
+        let address = self.server_packs.address.as_deref()?;
+        servers::load(&multiplayer::servers_file(&saves()))
+            .into_iter()
+            .find(|s| s.ip == address)?
+            .accept_textures
+    }
+    fn send_pack_status(&self, id: u128, status: i32) {
+        if let Some(r) = &self.remote {
+            r.session.send_pack_status(id, status);
+        }
+    }
+
+    /// The prompt's answer (`PackConfirmScreen`'s callback): the server's
+    /// setting follows it, declining a required pack disconnects, and every
+    /// pack it asked about is pushed.
+    pub(super) fn answer_pack_prompt(&mut self, yes: bool) -> Result<()> {
+        let Some(prompt) = self.server_packs.prompt.take() else {
+            return Ok(());
+        };
+        if self.player.is_some() && self.screen == super::Screen::Playing {
+            self.capture(true);
+        }
+        let setting = if yes {
+            self.server_packs.packs.allow();
+            Some(true)
+        } else {
+            self.server_packs.packs.reject();
+            if prompt.required {
+                let reason = Text::translate("multiplayer.requiredTexturePrompt.disconnect", &[]);
+                return self.leave_server(Some(reason.plain()));
+            }
+            Some(false)
+        };
+        for (id, url, hash) in prompt.requests {
+            self.server_packs.packs.push(id, &url, parse_sha1(&hash));
+        }
+        // ServerList.saveSingleServer.
+        if let Some(address) = &self.server_packs.address {
+            let file = multiplayer::servers_file(&saves());
+            let mut list = servers::load(&file);
+            for entry in list.iter_mut().filter(|s| &s.ip == address) {
+                entry.accept_textures = setting;
+            }
+            if let Err(e) = servers::save(&file, &list) {
+                log::warn!("Horizon: could not save {}: {e}", file.display());
+            }
+        }
+        Ok(())
+    }
+
+    /// Runs what the packs need (`createUpdateScheduler`): the downloads
+    /// that finished, the ones to start, a resource reload when the active
+    /// packs change, and the statuses for the server.
+    pub(super) fn tick_server_packs(&mut self) {
+        self.server_packs.notifiers.retain_mut(PackNotifier::poll);
+        // A reload waits for the world's resources (`reload_packs`).
+        if self.rest_loader.is_some() || self.world_loader.is_some() {
+            return;
+        }
+        let finished = self
+            .server_packs
+            .queue
+            .as_ref()
+            .map(download::Queue::finished)
+            .unwrap_or_default();
+        for batch in finished {
+            self.server_packs.packs.downloaded(batch);
+        }
+        while self.server_packs.packs.wants_tick() {
+            let tick = self.server_packs.packs.tick();
+            if !tick.download.is_empty() {
+                self.start_pack_downloads(tick.download);
+            }
+            if let Some(mut load) = tick.reload {
+                while let Some(recovery) = {
+                    let ok = self.reload_server_packs(&load);
+                    self.server_packs.packs.reloaded(ok)
+                } {
+                    load = recovery;
+                }
+            }
+        }
+        for (id, status) in self.server_packs.packs.take_replies() {
+            self.send_pack_status(id, status);
+        }
+    }
+    fn start_pack_downloads(&mut self, requests: Vec<horizon_client::server_packs::Request>) {
+        let state = &mut self.server_packs;
+        if state.queue.is_none() {
+            let dir = std::env::current_dir()
+                .unwrap_or_default()
+                .join("downloads");
+            match download::Queue::open(dir) {
+                Ok(queue) => state.queue = Some(queue),
+                Err(e) => {
+                    log::error!("Horizon: failed to open the download queue: {e}");
+                    // Every request failed, as the notifier would hear it.
+                    let (progress, events) = std::sync::mpsc::channel();
+                    for _ in &requests {
+                        let _ = progress.send(download::Progress::RequestStart);
+                        let _ = progress.send(download::Progress::RequestFinished(false));
+                    }
+                    state
+                        .notifiers
+                        .push(PackNotifier::new(events, requests.len()));
+                    let failed = requests.iter().map(|r| r.id).collect();
+                    state.packs.downloaded(horizon_client::server_packs::Batch {
+                        downloaded: Vec::new(),
+                        failed,
+                    });
+                    return;
+                }
+            }
+        }
+        let headers = download::headers(&state.user.0, state.user.1);
+        let (progress, events) = std::sync::mpsc::channel();
+        state
+            .notifiers
+            .push(PackNotifier::new(events, requests.len()));
+        if let Some(queue) = &state.queue {
+            queue.download(requests, headers, progress);
+        }
+    }
+    /// `DownloadedPackSource.startReload`: the packs on top of the player's
+    /// own, then `Minecraft.reloadResourcePacks`. False when a pack has no
+    /// readable `pack.mcmeta` or the reload failed.
+    fn reload_server_packs(&mut self, load: &[(u128, PathBuf)]) -> bool {
+        let packs: Option<Vec<_>> = load
+            .iter()
+            .map(|(id, path)| packs::server_pack(*id, path))
+            .collect();
+        let Some(packs) = packs else {
+            log::warn!("Horizon: invalid pack metadata in a server pack, ignoring all");
+            return false;
+        };
+        self.server_packs.active = packs;
+        match self.reload_selected_packs() {
+            Ok(()) => true,
+            Err(e) => {
+                log::warn!("Horizon: server resource pack reload failed: {e}");
+                false
+            }
+        }
+    }
+
+    pub(super) fn draw_pack_prompt(&self, batch: &mut HudBatch) {
+        let Some(prompt) = &self.server_packs.prompt else {
+            return;
+        };
+        let atlas = &self.gui.atlas;
+        let (w, h) = (batch.width, batch.height);
+        if self.player.is_none() {
+            // In place of the connecting screen, on its background.
+            batch.fill(
+                atlas,
+                0.0,
+                0.0,
+                w,
+                h,
+                horizon_client::hud::rgba(20, 20, 20, 255),
+            );
+        }
+        ui::menu_background(batch, atlas, 0.0, 0.0, w, h, self.player.is_some());
+        let (_, _, [yes, no]) = prompt.texts();
+        prompt
+            .layout(atlas, (w, h))
+            .draw(batch, atlas, self.cursor, [&yes, &no]);
+    }
+    /// The download notifiers' toasts, each in the next 32-pixel slot
+    /// below an advancement or recipe toast (`ToastManager`).
+    pub(super) fn draw_pack_toasts(&mut self, batch: &mut HudBatch) {
+        let multiplier = f64::from(self.settings.notification_display_time);
+        let mut slot = usize::from(!self.adv.toasts.is_empty());
+        for notifier in &mut self.server_packs.notifiers {
+            let Some(toast) = &mut notifier.toast else {
+                continue;
+            };
+            let (sound, finished) = toast.update(multiplier);
+            if let Some(show) = sound {
+                let event = if show { "ui.toast.in" } else { "ui.toast.out" };
+                self.audio
+                    .play(&format!("minecraft:{event}"), None, 1.0, 1.0);
+            }
+            if finished {
+                notifier.toast = None;
+                continue;
+            }
+            toast.draw(&self.gui.atlas, batch, 32.0 * slot as f32);
+            slot += 1;
+        }
+    }
+    /// A left click on the prompt: its answer when it hit a button.
+    pub(super) fn pack_prompt_click(&mut self) -> Result<()> {
+        let Some(prompt) = &self.server_packs.prompt else {
+            return Ok(());
+        };
+        let answer = prompt
+            .layout(&self.gui.atlas, self.gui_size())
+            .answer_at(self.cursor);
+        match answer {
+            Some(yes) => {
+                self.audio.play_button_click();
+                self.answer_pack_prompt(yes)
+            }
+            None => Ok(()),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use download::Progress::*;
+
+    fn notifier(total: usize, events: &[download::Progress]) -> PackNotifier {
+        let (send, receive) = std::sync::mpsc::channel();
+        for event in events {
+            send.send(*event).unwrap();
+        }
+        let mut notifier = PackNotifier::new(receive, total);
+        assert!(notifier.poll());
+        notifier
+    }
+    fn texts(n: &PackNotifier) -> (serde_json::Value, Option<serde_json::Value>) {
+        let (title, message) = n.text();
+        (title.component(), message.map(|m| m.component()))
+    }
+
+    #[test]
+    fn the_toast_counts_requests_and_shows_progress() {
+        let n = notifier(2, &[RequestStart]);
+        let (title, message) = texts(&n);
+        assert_eq!(title["translate"], "download.pack.title");
+        assert_eq!(title["with"], serde_json::json!([1, 2]));
+        assert_eq!(message, None);
+        let n = notifier(2, &[RequestStart, DownloadStart(Some(400)), Bytes(100)]);
+        assert_eq!(
+            texts(&n).1.unwrap(),
+            serde_json::json!({"translate": "download.pack.progress.percent", "with": [25]})
+        );
+        let n = notifier(1, &[RequestStart, DownloadStart(None), Bytes(1280)]);
+        assert_eq!(
+            texts(&n).1.unwrap()["with"],
+            serde_json::json!([{"text": "1.3 KB"}])
+        );
+    }
+
+    #[test]
+    fn a_failed_pack_turns_the_toast_into_the_failure_count() {
+        let events = [
+            RequestStart,
+            RequestFinished(false),
+            RequestStart,
+            DownloadStart(Some(3)),
+            Bytes(3),
+        ];
+        let (send, receive) = std::sync::mpsc::channel();
+        for event in events {
+            send.send(event).unwrap();
+        }
+        let mut n = PackNotifier::new(receive, 2);
+        assert!(n.poll());
+        // Not the last request yet: still downloading.
+        assert_eq!(texts(&n).0["translate"], "download.pack.title");
+        send.send(RequestFinished(true)).unwrap();
+        drop(send);
+        assert!(n.poll(), "the failure toast stays until it slides out");
+        let (title, message) = texts(&n);
+        assert_eq!(
+            title,
+            serde_json::json!({"translate": "download.pack.failed", "with": [1, 2]})
+        );
+        assert_eq!(message, None);
+    }
+
+    #[test]
+    fn a_finished_batch_without_a_toast_is_dropped() {
+        let (send, receive) = std::sync::mpsc::channel::<download::Progress>();
+        drop(send);
+        assert!(!PackNotifier::new(receive, 1).poll());
+    }
+
+    #[test]
+    fn sizes_read_as_realms_unit_human_readable() {
+        // com.mojang.realmsclient.Unit.humanReadable, run on the 26.3 jar.
+        for (bytes, text) in [
+            (0, "0 B"),
+            (1023, "1023 B"),
+            (1024, "1.0 KB"),
+            (1280, "1.3 KB"),
+            (1535, "1.5 KB"),
+            (10_000, "9.8 KB"),
+            (1_048_575, "1024.0 KB"),
+            (1_048_576, "1.0 MB"),
+            (52_428_800, "50.0 MB"),
+            (262_144_000, "250.0 MB"),
+            (1_073_741_824, "1.0 GB"),
+        ] {
+            assert_eq!(human_readable(bytes), text, "{bytes}");
+        }
+    }
+}

crates/horizon-client/src/game/shader_packs.rs

@@ -1,131 +1,84 @@
-//! The selected Horizon shader pack (`shaderPack` in `horizon-graphics.txt`,
-//! docs/shader-packs.md): loaded from `shaderpacks/`, given to the renderer,
-//! and loaded again when the selection changes, on F3 + T, or when its files
-//! change (checked twice a second). A pack that fails leaves the last good
-//! one (or the vanilla picture) on and says why in chat.
-use super::Game;
-use horizon_client::shader_pack::{self, ShaderPack, Stamp};
-use horizon_client::text::Text;
-use horizon_shaderpack::properties::SkyDirectives;
-use std::{
-    path::PathBuf,
-    time::{Duration, Instant},
-};
+//! Shader packs, for development until the Shader Packs page exists: `HORIZON_SHADER_PACK=<name>`
+//! runs `shaderpacks/<name>` (a folder or a zip beside `options.txt`) over the world. The
+//! programs of the current dimension's folder are loaded when the dimension changes (spec 1.2).
 
-#[derive(Default)]
-pub(super) struct ShaderPacks {
-    /// The pack the renderer runs.
-    pack: Option<ShaderPack>,
-    /// The selection and its files at the last load, success or not.
-    selected: String,
-    stamp: Stamp,
-    checked: Option<Instant>,
-}
+use horizon_client::camera::CameraFluid;
+use horizon_client::gfx::pack_uniforms::PackInputs;
+use horizon_shaders::{Macros, Pack, Properties, dimension_folder, load_post};
 
-impl ShaderPacks {
-    /// The loaded pack's folder name.
-    pub(super) fn id(&self) -> Option<&str> {
-        self.pack.as_ref().map(|p| p.id.as_str())
-    }
-    /// What a loaded Java pack changes in the vanilla sky of `dimension`
-    /// (0 overworld, -1 the Nether, 1 the End): its `sunPathRotation`, and
-    /// whether it keeps the clouds, sun and moon (Iris's sky mixins).
-    pub(super) fn java_sky(&self, dimension: i8) -> Option<(f32, SkyDirectives)> {
-        let java = self.pack.as_ref()?.java.as_ref()?;
-        let folder = &java.folders[java.folder_for(dimension)?];
-        Some((folder.directives.sun_path_rotation, java.sky))
-    }
-}
-
-pub(super) fn dir() -> PathBuf {
-    shader_pack::folder()
-}
+use super::{Dim, Game};
 
 impl Game<'_> {
-    /// Load the selected pack and give it to the renderer.
-    pub(super) fn load_shader_pack(&mut self) {
-        let id = self.settings.horizon.shader_pack.clone();
-        let dir = dir();
-        let state = &mut self.shader_packs;
-        state.selected = id.clone();
-        state.checked = Some(Instant::now());
-        let pack = if id.is_empty() {
-            state.stamp = Stamp::default();
-            None
-        } else {
-            state.stamp = Stamp::of(&dir.join(&id));
-            // Java packs are told which GPU they run on.
-            let (vendor, renderer) = self.renderer.as_ref().map_or(("Unknown", ""), |r| {
-                let name = r.info.name.as_str();
-                (
-                    horizon_client::java_pack::vendor_name(r.info.vendor, name),
-                    name,
-                )
-            });
-            let values = shader_pack::load_values(&dir, &id);
-            match ShaderPack::load_any(&dir.join(&id), &values, vendor, renderer) {
-                Ok(pack) => Some(pack),
-                Err(e) => return self.shader_pack_error(&id, &e),
-            }
+    /// Loads the pack for the current dimension when it changed, and returns this frame's
+    /// inputs to the pack's uniforms.
+    pub(super) fn shader_pack_inputs(&mut self, camera: glam::DVec3, partial: f32) -> PackInputs {
+        let Some(name) = std::env::var_os("HORIZON_SHADER_PACK") else {
+            return PackInputs::default();
         };
-        if let Some(r) = self.renderer.as_mut()
-            && let Err(e) = r.set_shader_pack(pack.as_ref(), &self.pack.render.sprite_layers)
+        let dimension = match self.dim {
+            Dim::Overworld => 0,
+            Dim::Nether => -1,
+            Dim::End => 1,
+        };
+        if let Some(renderer) = &mut self.renderer
+            && renderer.shader_pack_dimension() != Some(dimension)
         {
-            return self.shader_pack_error(&id, &e.to_string());
-        }
-        self.shader_packs.pack = pack;
-        self.ui.options.shader_pack_error = None;
-    }
-    /// Give the loaded pack to the renderer (also after it is rebuilt).
-    pub(super) fn apply_shader_pack(&mut self) -> horizon_client::Result<()> {
-        match self.renderer.as_mut() {
-            Some(r) => r.set_shader_pack(
-                self.shader_packs.pack.as_ref(),
-                &self.pack.render.sprite_layers,
-            ),
-            None => Ok(()),
-        }
-    }
-    /// Every frame: a new selection or edited pack files load it again.
-    pub(super) fn poll_shader_pack(&mut self) {
-        let state = &mut self.shader_packs;
-        if self.settings.horizon.shader_pack != state.selected {
-            return self.load_shader_pack();
-        }
-        if state.selected.is_empty()
-            || state
-                .checked
-                .is_some_and(|t| t.elapsed() < Duration::from_millis(500))
-        {
-            return;
-        }
-        state.checked = Some(Instant::now());
-        if Stamp::of(&dir().join(&state.selected)) != state.stamp {
-            self.load_shader_pack();
-        }
-    }
-    /// A file dropped on the window: a shader pack while the Shader Packs
-    /// page shows (`OptionsUi::drop_shader_pack`).
-    pub(super) fn drop_shader_pack(&mut self, path: &std::path::Path) {
-        match self.ui.options.drop_shader_pack(&mut self.settings, path) {
-            Some(Ok(())) => {
-                self.settings.save(&Self::options_path());
-                self.load_shader_pack();
+            let name = name.to_string_lossy();
+            let started = std::time::Instant::now();
+            let path = std::env::current_dir()
+                .unwrap_or_default()
+                .join("shaderpacks")
+                .join(&*name);
+            match Pack::open(&path) {
+                Ok(pack) => {
+                    let macros = Macros::standard();
+                    let text = pack.read_text("shaders.properties").unwrap_or_default();
+                    let properties = Properties::parse(&text, &macros);
+                    for note in &properties.notes {
+                        log::warn!(
+                            "shader pack {name}: shaders.properties:{}: {}",
+                            note.line,
+                            note.message
+                        );
+                    }
+                    let folder = dimension_folder(&pack, dimension);
+                    let post = load_post(&pack, &folder, &properties, &macros, None);
+                    if let Some((programs, notes)) = renderer.set_shader_pack(dimension, Some(post))
+                    {
+                        for note in notes {
+                            log::warn!("shader pack {name}: {note}");
+                        }
+                        log::info!(
+                            "shader pack {name}: folder `{folder}`, {} programs ({}) in {} ms",
+                            programs.len(),
+                            programs.join(" "),
+                            started.elapsed().as_millis()
+                        );
+                    }
+                }
+                Err(e) => {
+                    log::warn!("shader pack {name}: {e}");
+                    renderer.set_shader_pack(dimension, None);
+                }
             }
-            Some(Err(e)) => {
-                log::warn!("Horizon: shader pack {}: {e}", path.display());
-                self.system_message(Text::literal(format!("Shader pack: {e}")));
-            }
-            None => {}
         }
-    }
-    fn shader_pack_error(&mut self, id: &str, error: &str) {
-        log::warn!("Horizon: shader pack {id}: {error}");
-        // The Shader Packs page says why on the pack's row: the first line,
-        // since translator errors go on with a drawn source excerpt.
-        let first = error.lines().map(str::trim).find(|l| !l.is_empty());
-        self.ui.options.shader_pack_error =
-            Some((id.to_owned(), first.unwrap_or(error).to_owned()));
-        self.system_message(Text::literal(format!("Shader pack {id}: {error}")));
+        let lerp = |(old, new): (f32, f32)| old + (new - old) * partial;
+        let at = camera.floor().as_ivec3();
+        let light = self.world.light(at.x, at.y, at.z);
+        PackInputs {
+            day_time: self.world.day_time,
+            rain: lerp(self.world.weather.rain_level),
+            thunder: lerp(self.world.weather.thunder_level),
+            eye_in: match self.camera_fluid(camera.to_array()) {
+                CameraFluid::None => 0,
+                CameraFluid::Water => 1,
+                CameraFluid::Lava => 2,
+                CameraFluid::PowderSnow => 3,
+            },
+            blindness: f32::from(u8::from(self.potions.effects.get("blindness").is_some())),
+            eye_light: [i32::from(light & 15), i32::from(light >> 4)],
+            hide_gui: self.ui.hide_gui,
+            brightness: self.settings.gamma,
+        }
     }
 }

crates/horizon-client/src/game/startup_menu.rs

@@ -33,6 +33,7 @@ impl StartupMenu {
             Some(PendingWorldEntry::Server {
                 address: address.clone(),
                 name: options.player_name(),
+                cookies: None,
             })
         } else {
             options
@@ -125,6 +126,7 @@ impl StartupMenu {
             Action::Connect { address } => PendingWorldEntry::Server {
                 address,
                 name: player_name,
+                cookies: None,
             },
             _ => return,
         };
@@ -219,12 +221,11 @@ pub(super) fn spawn_loader(
         .name("resource-loader".into())
         .spawn(move || {
             let mut pack_error = None;
-            let root = packs::startup_root(&vanilla_root, &settings.resource_packs).unwrap_or_else(
-                |error| {
+            let root = packs::startup_root(&vanilla_root, &settings.resource_packs, &[])
+                .unwrap_or_else(|error| {
                     pack_error = Some(error.to_string());
                     vanilla_root.clone()
-                },
-            );
+                });
             let root = mods::content_root(&root, &settings.mods.enabled, &dev_mods);
             let result = load_resources(
                 root,
@@ -367,11 +368,6 @@ impl Loading {
                     let _ = std::fs::create_dir_all(&dir);
                     packs::open_folder(&dir);
                 }
-                Event::OpenShaderPackFolder => {
-                    let dir = horizon_client::shader_pack::folder();
-                    let _ = std::fs::create_dir_all(&dir);
-                    packs::open_folder(&dir);
-                }
                 Event::Credits => {
                     if let Some(gui) = &self.gui {
                         let name = self.options.as_ref().map_or_else(
@@ -387,9 +383,6 @@ impl Loading {
                         self.menu.win = Some((screen, Instant::now()));
                     }
                 }
-                Event::ReloadShaderPack => {
-                    self.save_menu_settings();
-                }
                 // The startup menu runs before the game opens a control socket.
                 Event::ButtonClick | Event::CopyAgentDetails => {}
             }
@@ -455,17 +448,6 @@ impl Loading {
                 }
                 self.apply_menu_settings();
             }
-            WindowEvent::DroppedFile(path) => {
-                match self
-                    .menu
-                    .options
-                    .drop_shader_pack(&mut self.settings, &path)
-                {
-                    Some(Ok(())) => self.save_menu_settings(),
-                    Some(Err(e)) => log::warn!("Horizon: shader pack {}: {e}", path.display()),
-                    None => {}
-                }
-            }
             WindowEvent::RedrawRequested => self.draw(),
             WindowEvent::ModifiersChanged(modifiers) => self.menu.modifiers = modifiers.state(),
             WindowEvent::Focused(false) => {
@@ -782,7 +764,7 @@ mod tests {
             "Guest".into(),
         );
         assert!(
-            matches!(menu.pending.take(), Some(PendingWorldEntry::Server { address, name })
+            matches!(menu.pending.take(), Some(PendingWorldEntry::Server { address, name, .. })
             if address == "localhost:25565" && name == "Guest")
         );
         assert!(menu.pending.take().is_none(), "an entry is consumed once");

crates/horizon-client/src/game/text_displays.rs

@@ -0,0 +1,302 @@
+//! Server text displays: metadata, interpolation, billboard transforms and world text.
+use super::Game;
+use horizon_client::{
+    hud::{HudBatch, rgba},
+    mesher::Vertex,
+    text::Text,
+    text_display::{Align, TextDisplayData},
+};
+use horizon_protocol::entity_data::Value;
+
+pub(super) struct RemoteTextDisplay {
+    pub data: TextDisplayData,
+    from: TextDisplayData,
+    shown: TextDisplayData,
+    position: glam::DVec3,
+    previous: glam::DVec3,
+    target: glam::DVec3,
+    rotation: [f32; 2],
+    old_rotation: [f32; 2],
+    target_rotation: [f32; 2],
+    steps: i32,
+    age: i64,
+    start: i64,
+    duration: i32,
+    dirty: bool,
+    start_dirty: bool,
+    duration_dirty: bool,
+    initialized: bool,
+    /// `Display.lastProgress`: the progress the last frame drew, where a new
+    /// interpolation starts from.
+    last_progress: f32,
+    /// `TextDisplay.clientDisplayCache`: the split lines, until the render
+    /// state changes.
+    lines: Option<Lines>,
+}
+
+/// `TextDisplay.CachedInfo`: each line and its width, and the widest.
+struct Lines {
+    lines: Vec<(Text, f32)>,
+    width: f32,
+}
+
+/// `Display.RENDER_STATE_IDS` and `TextDisplay.TEXT_RENDER_STATE_IDS`: the
+/// data a render state is built from (not the view range, size or glow).
+fn renders(id: u8) -> bool {
+    matches!(id, 11..=16 | 18 | 19 | 23..=27)
+}
+
+impl RemoteTextDisplay {
+    pub fn new(position: [f64; 3], yaw: f32) -> Self {
+        Self {
+            data: Default::default(),
+            from: Default::default(),
+            shown: Default::default(),
+            position: position.into(),
+            previous: position.into(),
+            target: position.into(),
+            rotation: [yaw, 0.0],
+            old_rotation: [yaw, 0.0],
+            target_rotation: [yaw, 0.0],
+            steps: 0,
+            age: 0,
+            start: 0,
+            duration: 0,
+            dirty: true,
+            start_dirty: false,
+            duration_dirty: false,
+            initialized: false,
+            last_progress: 0.0,
+            lines: None,
+        }
+    }
+    fn progress(&self, partial: f32) -> f32 {
+        if self.duration <= 0 {
+            1.0
+        } else {
+            (((self.age - self.start) as f32 + partial) / self.duration as f32).clamp(0.0, 1.0)
+        }
+    }
+    pub fn metadata(&mut self, values: &[(u8, i32, Value)]) {
+        self.start_dirty |= values.iter().any(|v| v.0 == 8);
+        self.duration_dirty |= values.iter().any(|v| v.0 == 9);
+        self.dirty |= values.iter().any(|v| renders(v.0));
+        self.data.apply(values);
+    }
+    fn tick(&mut self) {
+        self.age += 1;
+        self.previous = self.position;
+        self.old_rotation = self.rotation;
+        if self.steps > 0 {
+            self.position += (self.target - self.position) / f64::from(self.steps);
+            for i in 0..2 {
+                self.rotation[i] +=
+                    angle(self.target_rotation[i] - self.rotation[i]) / self.steps as f32;
+            }
+            self.steps -= 1;
+        }
+        if self.start_dirty {
+            self.start = self.age + i64::from(self.data.interpolation_delay);
+        }
+        if self.duration_dirty {
+            self.duration = self.data.interpolation_duration;
+        }
+        if self.dirty {
+            self.from = if self.initialized && self.duration > 0 {
+                self.shown.blend(&self.from, self.last_progress)
+            } else {
+                self.data.clone()
+            };
+            self.shown = self.data.clone();
+            self.initialized = true;
+            self.lines = None;
+        }
+        self.dirty = false;
+        self.start_dirty = false;
+        self.duration_dirty = false;
+    }
+    fn move_to(&mut self, position: [f64; 3], rotation: Option<(f32, f32)>) {
+        self.target = position.into();
+        if let Some((yaw, pitch)) = rotation {
+            self.target_rotation = [yaw, pitch];
+        }
+        self.steps = self.data.teleport_duration.clamp(0, 59);
+        if self.steps == 0 {
+            self.position = self.target;
+            self.previous = self.target;
+            self.rotation = self.target_rotation;
+            self.old_rotation = self.rotation;
+        }
+    }
+}
+fn angle(d: f32) -> f32 {
+    (d + 180.0).rem_euclid(360.0) - 180.0
+}
+
+impl Game<'_> {
+    pub(super) fn move_remote_text_display(
+        &mut self,
+        id: i32,
+        position: [f64; 3],
+        rotation: Option<(f32, f32)>,
+    ) {
+        if let Some(d) = self.text_displays.get_mut(&id) {
+            d.move_to(position, rotation);
+        }
+    }
+    pub(super) fn tick_text_displays(&mut self) {
+        for display in self.text_displays.values_mut() {
+            display.tick();
+        }
+    }
+    pub(super) fn text_display_geometry(
+        &mut self,
+        camera: glam::DVec3,
+        partial: f64,
+        normal: &mut Vec<Vertex>,
+        see_through: &mut Vec<Vertex>,
+    ) {
+        self.text_display_vertices = 0;
+        let atlas = &self.gui.atlas;
+        let front = self.camera_type == super::perspective::CameraType::ThirdPersonFront;
+        let angles = if front {
+            [self.yaw + 180.0, -self.pitch]
+        } else {
+            [self.yaw, self.pitch]
+        };
+        for display in self.text_displays.values_mut() {
+            display.last_progress = display.progress(partial as f32);
+            let d = display.shown.blend(&display.from, display.last_progress);
+            let position = display.previous.lerp(display.position, partial);
+            let range = f64::from(d.view_range) * 64.0 * f64::from(self.settings.entity_distance);
+            if position.distance_squared(camera) >= range * range || d.text.is_empty() {
+                continue;
+            }
+            let rotation = std::array::from_fn(|i| {
+                display.old_rotation[i]
+                    + angle(display.rotation[i] - display.old_rotation[i]) * partial as f32
+            });
+            let mut matrix = glam::Mat4::from_translation((position - camera).as_vec3())
+                * d.matrix(rotation, angles)
+                * glam::Mat4::from_rotation_y(std::f32::consts::PI)
+                * glam::Mat4::from_scale(glam::Vec3::splat(-0.025));
+            if !matrix.is_finite() {
+                continue;
+            }
+            // TextDisplayRenderer.splitLines: Font.split, no indent on wrapped lines.
+            let Lines { lines, width } = display.lines.get_or_insert_with(|| {
+                let lines: Vec<_> = atlas
+                    .font
+                    .split(&d.text, d.line_width as f32)
+                    .into_iter()
+                    .map(|line| {
+                        let width = atlas.font.width_text(&line).ceil();
+                        (line, width)
+                    })
+                    .collect();
+                let width = lines.iter().map(|l| l.1).fold(0.0, f32::max);
+                Lines { lines, width }
+            });
+            let width = *width;
+            let height = lines.len() as f32 * 10.0 - 1.0;
+            matrix *=
+                glam::Mat4::from_translation(glam::Vec3::new(1.0 - width / 2.0, -height, 0.0));
+            let mut batch = HudBatch::new([1, 1]);
+            let bg = if d.flags & 4 != 0 {
+                self.settings.text_background(0.25)
+            } else {
+                d.background as u32
+            };
+            if bg != 0 {
+                batch.fill(
+                    atlas,
+                    -1.0,
+                    -1.0,
+                    width + 1.0,
+                    height + 1.0,
+                    rgba(
+                        (bg >> 16) as u8,
+                        (bg >> 8) as u8,
+                        bg as u8,
+                        (bg >> 24) as u8,
+                    ),
+                );
+            }
+            let align = d.align();
+            for (i, (line, line_width)) in lines.iter().enumerate() {
+                let x = match align {
+                    Align::Left => 0.0,
+                    Align::Right => width - line_width,
+                    Align::Center => (width - line_width) / 2.0,
+                };
+                batch.text_styled(
+                    atlas,
+                    line,
+                    x,
+                    i as f32 * 10.0,
+                    rgba(255, 255, 255, d.opacity as u8),
+                    d.flags & 1 != 0,
+                );
+            }
+            let world_light = self.world.light(
+                position.x.floor() as i32,
+                position.y.floor() as i32,
+                position.z.floor() as i32,
+            );
+            let light = if d.brightness == -1 {
+                horizon_client::block_entity_render::vertex_light(world_light)
+            } else {
+                ((d.brightness as u32 >> 20 & 15) * 16)
+                    | (((d.brightness as u32 >> 4 & 15) * 16) << 8)
+            };
+            let through = d.flags & 2 != 0;
+            let out = if through {
+                &mut *see_through
+            } else {
+                &mut *normal
+            };
+            for quad in batch.vertices.as_chunks::<6>().0 {
+                for i in [0, 1, 2, 5] {
+                    let v = quad[i];
+                    let point =
+                        matrix.transform_point3(glam::Vec3::new(v.pos[0], v.pos[1], v.depth));
+                    out.push(Vertex {
+                        pos: point.to_array(),
+                        uv: v.uv,
+                        color: v.color,
+                        light,
+                        layer: if through { 2 } else { 0 },
+                        normal: [0; 4],
+                    });
+                }
+            }
+            self.text_display_vertices += batch.vertices.len() / 6 * 4;
+            self.map_patches.extend(batch.patches);
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn metadata_and_position_interpolation_keep_their_separate_clocks() {
+        let mut d = RemoteTextDisplay::new([0.0; 3], 0.0);
+        d.tick();
+        d.metadata(&[
+            (8, 1, Value::Int(0)),
+            (9, 1, Value::Int(4)),
+            (10, 1, Value::Int(2)),
+            (11, 0, Value::Floats(vec![4.0, 0.0, 0.0])),
+        ]);
+        d.tick();
+        assert_eq!(d.shown.blend(&d.from, d.progress(0.5)).translation[0], 0.5);
+        d.move_to([2.0, 0.0, 0.0], Some((90.0, 0.0)));
+        d.tick();
+        assert_eq!(d.position.x, 1.0);
+        assert_eq!(d.rotation[0], 45.0);
+        d.tick();
+        assert_eq!(d.position.x, 2.0);
+        assert_eq!(d.shown.blend(&d.from, d.progress(0.0)).translation[0], 2.0);
+    }
+}

crates/horizon-client/src/game/wither.rs

@@ -2,10 +2,8 @@
 //! its boss bar, and its skulls hitting and exploding.
 use super::Game;
 use horizon_client::{
-    hud_overlays,
     mobs::{Damage, DamageKind, Species, Who},
     projectiles::{Projectile, ProjectileKind},
-    text::Text,
 };
 
 impl Game<'_> {
@@ -78,45 +76,6 @@ impl Game<'_> {
         }
         Ok(())
     }
-    /// The wither boss bars (purple), within range.
-    pub(super) fn wither_bars(&self, bars: &mut Vec<hud_overlays::BossBar>) {
-        let Some(p) = self.player.as_ref() else {
-            return;
-        };
-        for m in self
-            .mobs
-            .iter()
-            .filter(|m| m.species() == Species::Wither && m.alive())
-        {
-            if m.position.distance_squared(p.position) > 64.0 * 64.0 {
-                continue;
-            }
-            let progress = if m.extra.counter > 0 {
-                1.0 - m.extra.counter as f32 / horizon_client::mobs::wither::INVULNERABLE as f32
-            } else {
-                (m.health / m.attrs.max_health).clamp(0.0, 1.0)
-            };
-            let name = m
-                .custom_name
-                .clone()
-                .unwrap_or_else(|| self.translate("entity.minecraft.wither", "Wither"));
-            bars.push(hud_overlays::BossBar {
-                name: Text::literal(name),
-                progress,
-                color: 5,
-                overlay: 0,
-            });
-        }
-    }
-    pub(super) fn wither_near(&self) -> bool {
-        self.player.as_ref().is_some_and(|p| {
-            self.mobs.iter().any(|m| {
-                m.species() == Species::Wither
-                    && m.alive()
-                    && m.position.distance_squared(p.position) <= 64.0 * 64.0
-            })
-        })
-    }
     /// `WitherSkull.onHitEntity` / `onHit`: 8 damage (healing the wither 5
     /// when it kills), withering for 10 seconds, then a power 1 blast.
     pub(super) fn wither_skull_hit(