Merge pull request #8718 from TheApple05/feature/older-servers-1.21.8

Older servers: experimental native adapters for 1.20.2–1.21.8

AGENTS.md

@@ -51,7 +51,7 @@ Game workspace (root `Cargo.toml`); `launcher/` and `crates/horizon-telemetry-se
 | `horizon-command` | Command parsing (Brigadier): the vanilla tree, argument types, selectors, suggestions, the tree's network form. Re-exported as `horizon_client::command` |
 | `horizon-client-core` | The client lib's bottom layer: `text.rs`, `lang.rs`, `snbt.rs`, `nbt_path.rs`, `component.rs`, `scoreboard.rs`, `bossbar.rs`, `gamerules.rs`, `block_entity_nbt.rs`, registry/particle/sound tables. Re-exported under the old paths (`horizon_client::text`...) |
 | `horizon-client-input` | Key bindings and key names, toggle keys, mouse options, controller settings and glyphs, the clipboard, window options (`keybinds.rs`, `gamepad.rs`, `mouse.rs`, `window.rs`...). Re-exported under the old paths |
-| `horizon-client-render` | The client's world data, rendering and screens (chunks, meshing, light, streaming, `gfx`, HUD, menus, settings): ~80 modules that horizon-client re-exports under the same paths. Nothing in it reaches gameplay |
+| `horizon-client-render` | The client's world data, rendering and screens (chunks, meshing, light, streaming, `gfx`, HUD, menus, settings), modules that horizon-client re-exports under the same paths. Nothing in it reaches gameplay |
 | `horizon-world` | Vanilla world data with no gameplay loop: NBT, regions, chunks, `datafix/`, `worldgen/`, `level/` (server-side block behaviour, ticks, redstone), entity physics, items, effects, food, damage |
 | `horizon-core` | Simulation primitives: Java `Random`s, `jmath` (HotSpot-exact `Math`), positions, noise, density, paletted storage, `version.rs` (the pinned version) |
 | `horizon-protocol` | Network protocol 777: codecs, framing, encryption, `packets/{handshake,status,login,configuration,play}.rs`, `entity_data.rs` |
@@ -65,6 +65,7 @@ Game workspace (root `Cargo.toml`); `launcher/` and `crates/horizon-telemetry-se
 | `horizon-mods`, `cargo-horizon-mod` | Content mods (`.hmod`: manifest, content fence, no code), the registry index and `.hpack`, and `cargo horizon-mod` (`new`, `build`, `run`, `check`, `registry`) ([docs/mods.md](docs/mods.md)). Code mods are native, built by the launcher ([docs/native-mods.md](docs/native-mods.md)) |
 | `horizon-port-pack` | Porting Java modpacks ([docs/modpacks.md](docs/modpacks.md)) |
 | `horizon-optifine` | OptiFine-format pack files below every feature that reads them: `.properties`, the name/range/block matchers, paths and `optifine/` folders, and custom entity models (`cem/`: `.jem`/`.jpm` parsing and baking) |
+| `horizon-polytone` | Polytone-format pack files (`assets/*/polytone/`), read clean-room from the public wiki: targets, biome and dimension modifiers and their environment attribute layers (#11486) |
 | `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 |
@@ -92,8 +93,8 @@ reads `README.md`, `launcher/links.json`, `docs/api/`, `roadmap/roadmap.json` an
 ```sh
 python3 tools/pr_ready.py                  # the self-check: fmt, clippy -D warnings, touched crates' tests, harnesses; paste its block in the PR
 python3 tools/pr_ready.py --quick          # same without harnesses
-cargo test -p horizon-client -p horizon-client-lib --lib --bins --tests   # skips the 104 examples (pr_ready does this); `--doc` separately
-cargo test -p horizon-client-lib --lib mod_content::tests:: -- --ignored   # the 5 slow content-root tests, #[ignore]d; pr_ready runs them when mod content, assets, blocks or items change
+cargo test -p horizon-client -p horizon-client-lib --lib --bins --tests   # skips the examples (pr_ready does this); `--doc` separately
+cargo test -p horizon-client-lib --lib mod_content::tests:: -- --ignored   # the slow content-root tests, #[ignore]d; pr_ready runs them when mod content, assets, blocks or items change
 cargo build --profile fast -p horizon-client        # optimized, quick to link: use it to play or run lan_e2e
 python3 tools/parity.py --changed origin/main       # the harnesses your branch can affect (CI's parity job)
 python3 tools/parity.py --changed-files paths.txt --list   # which harnesses cover these files, without running them
@@ -105,8 +106,8 @@ python3 tools/agent_control_e2e.py         # horizon-ctl / MCP end to end
 - Harnesses and the game need the vanilla data in `.local/` (`minecraft/`, `horizon-client/26.3`, `datagen/`,
   `tools/`): see [docs/parity-workflow.md](docs/parity-workflow.md). Without it, pr_ready lists the
   harnesses for CI.
-- A harness = `tools/test_<name>_parity.py` (324 of them) + a Java oracle (`mods/horizon/src/test/java/dev/horizonlab/parity/Vanilla*Oracle.java`)
-  + a Rust probe: `crates/<crate>/examples/<name>_{probe,fixture}.rs` (horizon-world 175, horizon-client 104),
+- A harness = `tools/test_<name>_parity.py` + a Java oracle (`mods/horizon/src/test/java/dev/horizonlab/parity/Vanilla*Oracle.java`)
+  + a Rust probe: `crates/<crate>/examples/<name>_{probe,fixture}.rs` (mostly horizon-world and horizon-client),
   or the game binary with a fixture env var (`game/dispense_fixture.rs`, `game/sculk_fixture.rs`,
   `game/command_harness.rs`, `game/net_harness.rs`). Copy a nearby harness for a new one.
 - Developing a native mod? Run `horizon-launcher settings native-profile dev` once. `dev` builds the game crate
@@ -120,7 +121,7 @@ python3 tools/agent_control_e2e.py         # horizon-ctl / MCP end to end
   Source paths remain in `crates/horizon-client/`. Measure actual harness selection on refreshed
   records with `tools/parity.py --changed-files paths.txt --list`; historical counts are not a guarantee.
 - Rust integration tests: `crates/horizon-client/tests/` (`lan_bot.rs`, `generation_saves.rs`, `streaming_meshes.rs`).
-- Linux needs `libasound2-dev libudev-dev`; `--no-default-features` drops audio and controllers (the server build).
+- Linux needs `libasound2-dev libudev-dev`; `--no-default-features` drops audio, controllers, `discord`, `friends` and `heartbeat` (the server build).
 - Run and drive the game (starts the `horizon-client` beside `horizon-ctl`; other arguments go to the game):
   `target/fast/horizon-ctl --socket $PWD/ctl.sock launch --world W --creative --offscreen --wait --resources $PWD/.local/horizon-client/26.3`,
   then `horizon-ctl --socket … state|keys|turn|command|screenshot|quit`
@@ -151,23 +152,23 @@ state stays separate from the library tests. This compiles gameplay twice for ex
 
 | Subsystem | Files |
 |---|---|
-| Game loop, tick, frame | `game.rs`: `fn run`, `impl ApplicationHandler for Game` (`window_event`, `about_to_wait`), `fn tick`, `fn tick_world`, `fn render`; L: `clock.rs`, `spans.rs`; `horizon-client-input/src/window.rs` |
-| Rendering | L: `gfx.rs` (`Renderer::new`, `Renderer::render`), `gfx/` (cull, occlusion, translucency, upload, timing, lod, weather, stars, end_sky), `*.wgsl`, `particles.rs`, `block_entity_render.rs`, `item_render.rs`, `fog.rs`, `clouds.rs`, `camera.rs`, `first_person.rs`; G: `render_tick.rs`, `item_draw.rs` |
-| Chunks, streaming, light | L: `streaming.rs` (worker pool: generate, light, mesh), `world.rs`, `chunk.rs`, `chunk_map.rs`, `light.rs`, `mesher.rs` + `mesher/`, `vanillagen.rs` (binds horizon-world's generator), `lod.rs` + `lod/`, `server_terrain.rs` (a server's kept chunks), `bluemap.rs` + `bluemap_detect.rs` (far terrain from its web map), `ticket_levels.rs`; G: `world_loading.rs`, `postprocess.rs`; game.rs `fn update_world` |
+| Game loop, tick, frame | `game.rs`: `fn run`, `fn tick`, `fn tick_world`, `fn render`; G: `window_handler.rs` (`impl ApplicationHandler for Game`: `window_event`, `about_to_wait`); L: `clock.rs`, `spans.rs`; `horizon-client-input/src/window.rs` |
+| Rendering | L: `gfx.rs` (`Renderer::new`, `Renderer::render`), `gfx/` (cull, occlusion, translucency, upload, timing, lod, weather, stars, end_sky), `*.wgsl`, `particles.rs`, `block_entity_render.rs`, `item_render.rs`, `fog.rs`, `clouds.rs`, `camera.rs`, `first_person.rs`; G: `render_tick.rs`, `item_draw.rs`, `screen_backgrounds.rs` (panorama, menu blur, border wall) |
+| Chunks, streaming, light | L: `streaming.rs` (worker pool: generate, light, mesh), `world.rs`, `chunk.rs`, `chunk_map.rs`, `light.rs`, `mesher.rs` + `mesher/`, `vanillagen.rs` (binds horizon-world's generator), `lod.rs` + `lod/`, `server_terrain.rs` (a server's kept chunks), `bluemap.rs` + `bluemap_detect.rs` (far terrain from its web map), `ticket_levels.rs`; G: `world_loading.rs`, `world_entry.rs`, `postprocess.rs`; game.rs `fn update_world` |
 | World generation | `crates/horizon-world/src/worldgen/` (`generator*.rs`, `feature_graph.rs`, `structure/`, `carver/`) |
 | Block behaviour | `crates/horizon-world/src/level/` (`mod.rs`, `tick.rs`, `hooks.rs`, `redstone.rs`, `place.rs`, `interact.rs`); game.rs `fn tick_blocks`, `fn process_level_events` |
 | Mobs | L: `mobs.rs` (types), `mobs/` (`ai.rs`, `goals.rs`, `brain.rs`, `*_brain.rs`, `nav.rs`, `path.rs`, `species.rs`, `spawning.rs`, `render.rs`, `anim.rs`); G: `creatures.rs` (ticking, spawning, mob events), one file per mob family (`dragon.rs`, `wither.rs`, `villagers.rs`, `piglins.rs`, `golems.rs`...), `natural_spawning.rs` |
 | Other entities | L: `entities.rs`, `projectiles.rs`, `arrows.rs`; G: `boats.rs`, `minecarts.rs`, `mounts.rs`, `armor_stands.rs`, `paintings.rs`, `frames.rs`, `fireworks.rs`, `tnt.rs`, `explosion.rs` |
-| Player actions | game.rs (`fn use_hand`, `fn use_item`, `fn attack`, `fn tick_mining`, `fn break_block`); G: `hand.rs`, `combat.rs`, `consume.rs`, `potions.rs`, `shield.rs`, `crossbow.rs`, `trident.rs`, `fishing.rs`; L: `motion.rs` + `motion/` (movement), `collisions.rs`; crate `horizon-items`: `items.rs`, `item_data.rs`, `enchant.rs`, `blocks.rs` |
-| Inventory and containers | L: `menu.rs` (`AbstractContainerMenu.clicked`), `container_screen.rs`, `containers.rs`, `creative.rs`, `crafting.rs`, `recipe_book*.rs`, `stations.rs`, `merchant.rs`; game.rs `fn menu_ops`, `fn click_inventory`; G: `stations.rs`, `trading.rs`, `recipe_book.rs`, `machines.rs` |
+| Player actions | game.rs (`fn use_hand`, `fn tick_mining`, `fn break_block`); G: `item_actions.rs` (`fn use_item`), `melee.rs` (`fn attack`), `hand.rs`, `combat.rs`, `consume.rs`, `using_item.rs` (an item in use, tick by tick), `potions.rs`, `shield.rs`, `crossbow.rs`, `trident.rs`, `fishing.rs`; L: `motion.rs` + `motion/` (movement), `collisions.rs`; crate `horizon-items`: `items.rs`, `item_data.rs`, `enchant.rs`, `blocks.rs` |
+| Inventory and containers | L: `menu.rs` (`AbstractContainerMenu.clicked`), `container_screen.rs`, `containers.rs`, `creative.rs`, `crafting.rs`, `recipe_book*.rs`, `stations.rs`, `merchant.rs`; game.rs `fn menu_ops`, `fn click_inventory`; G: `stations.rs`, `trading.rs`, `recipe_book.rs`, `machines.rs`, `inventory_input.rs` (keys and clicks over a container), `inventory_slots.rs` (slot layout and drawing) |
 | Commands | parse: crate `horizon-command` (`args.rs`, `selector.rs`, `tree_*.rs`, `vanilla.rs`); run: G: `commands.rs` (dispatch) + `commands/*.rs` (`admin`, `execute`, `items`, `players`, `world_cmds`...); L: `scoreboard_cmd.rs`, `data_cmd.rs`; `horizon-client-core`: `nbt_path.rs`, `scoreboard.rs`; G: `functions.rs`, `command_blocks.rs` |
-| UI screens | `Screen` enum in game.rs; L: `title.rs` + `title/`, `options_ui.rs`, `multiplayer.rs`, `pack_screen.rs`, `graphics_ui.rs`, `screen_draw.rs`, `ui.rs` (widgets), `hud.rs`, `hud_layout.rs`, `hud_overlays.rs`, `chat.rs`, `tab_list.rs`; G: `startup_menu.rs`, `screens.rs` (pause, death), `options.rs`, `lan_screen.rs`, `chat.rs`, `sign_edit.rs`, `books.rs` |
+| UI screens | `Screen` enum in game.rs; L: `title.rs` + `title/`, `options_ui.rs`, `multiplayer.rs`, `pack_screen.rs`, `graphics_ui.rs`, `screen_draw.rs`, `ui.rs` (widgets), `hud.rs`, `hud_layout.rs`, `hud_overlays.rs`, `chat.rs`, `tab_list.rs`; G: `startup_menu.rs`, `loading_screen.rs` (the loading screen, the pre-game `App`), `screens.rs` (pause, death), `options.rs`, `lan_screen.rs`, `chat.rs`, `sign_edit.rs`, `books.rs`, `creative_screen.rs` |
 | Multiplayer client | L: `net.rs` (network thread); G: `remote.rs` (`fn handle_packet`, `fn tick_remote`), `remote_*.rs` (mob data, objects, projectiles, vehicles, stations) |
 | LAN host / server side | L: `lan/` (`conn.rs` handshake + login threads, `hub.rs` + `hub/` play state, `chunks.rs`, `entity.rs`, `tracking.rs`, `guest.rs`, `playerdata.rs`); G: `lan.rs` (`LanHost`), `lan_actions.rs` (`fn as_guest`, `fn tick_guests`), `lan_*.rs` per feature, `lan_entities.rs` (tracked entities) |
 | Integrated server | G: `integrated.rs` (the server thread), `levels.rs` (one level per dimension, `fn tick_server`), `server_travel.rs` |
 | Dedicated server | G: `dedicated.rs`, `dedicated/status.rs`; crates `horizon-server-files`, `horizon-server`, `horizon-anticheat` (L: `lan/anticheat.rs`) |
-| Save and load | L: `save.rs` (level.dat, regions, playerdata), `entity_nbt.rs`, `options_file.rs`; `horizon-client-core/src/block_entity_nbt.rs`; G: `saving.rs`, `persist.rs` (entities); `crates/horizon-world/src/{region.rs,nbt.rs,datafix/}` |
-| Input | game.rs `fn window_event`, `fn key_pressed`, `fn play_mouse`; crate `horizon-client-input` (`keybinds.rs`, `keymapping.rs`, `key_names.rs`, `mouse.rs`, `input.rs`, `interaction_input.rs`, `gamepad.rs`, `clipboard.rs`); L: `osk.rs`; G: `pad.rs`, `pad_menu.rs` |
+| Save and load | L: `save.rs` (level.dat, regions, playerdata), `entity_nbt.rs`, `options_file.rs`; `horizon-client-core/src/block_entity_nbt.rs`; G: `saving.rs`, `persist.rs` (entities), `world_session.rs` (opening and closing a world); `crates/horizon-world/src/{region.rs,nbt.rs,datafix/}` |
+| Input | game.rs `fn window_event`; G: `play_keys.rs` (`fn key_pressed`), `play_input.rs` (`fn play_mouse`, toggled keys, the hotbar wheel); crate `horizon-client-input` (`keybinds.rs`, `keymapping.rs`, `key_names.rs`, `mouse.rs`, `input.rs`, `interaction_input.rs`, `gamepad.rs`, `clipboard.rs`); L: `osk.rs`; G: `pad.rs`, `pad_menu.rs`, `pointer_capture.rs` (mouse look, pointer grab) |
 | 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`, `mobs/cem.rs` + `mobs/cem_anim.rs` (OptiFine/EMF entity models and their animations); `horizon-client-core/src/lang.rs`; crates `horizon-assets`, `horizon-optifine`; G: `packs.rs` |
 | Agent control | L: `control.rs` (socket), `bin/horizon-ctl/`; G: `control.rs`, `agent.rs`, `events.rs`, `ui_control.rs` ([docs/agent-control.md](docs/agent-control.md)) |
@@ -176,7 +177,7 @@ state stays separate from the library tests. This compiles gameplay twice for ex
 
 ## How `Game` is organised
 
-- `struct Game` (game.rs, ~290 fields) holds everything. Its methods are spread over ~180 files: game.rs keeps
+- `struct Game` (game.rs) holds everything. Its methods are spread over many files: game.rs keeps
   the core (tick, render, input, inventory, world open/close) and each `game/<feature>.rs` adds an
   `impl Game<'_>` block for one feature, with its own state types. Fields stay private to the gameplay module and its descendants. Gameplay tests run in the gameplay library, separate from reusable-library tests.
 - Find a feature's code: `grep -rn "fn tick_<thing>\|fn <verb>_<thing>" crates/horizon-client/src/game*`;
@@ -190,7 +191,7 @@ state stays separate from the library tests. This compiles gameplay twice for ex
   `levels.rs` swaps whole dimensions in the same way. Changes reach clients through the block log, level
   events and the entity tracker (`lan/tracking.rs`, `game/lan_entities.rs`).
 - Shared read-only data: `Resources` (`res`: blocks, items, recipes, mob types, biomes) and `PackResources`
-  (`pack`), both in game.rs.
+  (`pack`), both in game.rs, their methods in `game/resource_tables.rs`.
 
 ## Single player runs on a server thread
 

CONTRIBUTING.md

@@ -33,7 +33,7 @@ queue (the hub, or `/suggest` on Discord) rather than to issues, which are for b
 Wherever vanilla has a feature, vanilla is the specification, down to the order of random calls. "Parity" here means
 Horizon gives the same results as the pinned 26.3 client and server for the same inputs, checked by a **harness**: a
 `tools/test_*_parity.py` script that runs a small Java oracle against the real game and a Rust probe against Horizon,
-and compares their outputs. There are about 290 of them.
+and compares their outputs.
 
 - **Read the vanilla code before writing Horizon's.** `tools/rea_vanilla.py` queries the pinned game bytecode:
   `python3 tools/rea_vanilla.py method net.minecraft.world.level.block.DispenserBlock dispenseFrom`.
@@ -61,6 +61,10 @@ another project's source may also be read and used, **only when that project's l
   "source available" licenses, all rights reserved (OptiFine), and any project with no license or an unclear one.
   Don't read, copy, translate or paraphrase their source, and don't send code an AI tool wrote from it. Being able
   to download a mod or a pack does not give you the right to read its files.
+- **Java's own library is GPL too.** OpenJDK's source (`java.lang.Math`, `StrictMath`, `FdLibm`, `HashMap`, the
+  sorts, `Double.toString`, HotSpot's intrinsics...) is GPL-2.0, so it is off limits like the rest. Reproduce Java's
+  behaviour from its API documentation (the Javadoc) and from what a JVM returns, or from a permissive original such
+  as Sun's fdlibm C sources (see [THIRD_PARTY_NOTICES.md](THIRD_PARTY_NOTICES.md)); see #6741.
 - **Check the license yourself.** Read the LICENSE file at the commit you use and the header of each file you take:
   some repositories mix licenses, and a file under another license is off limits. A license that changed: the one at
   your commit counts. In doubt, don't: ask in #contributors first.

Cargo.lock

@@ -131,9 +131,9 @@ dependencies = [
 
 [[package]]
 name = "arboard"
-version = "3.6.1"
+version = "3.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0348a1c054491f4bfe6ab86a7b6ab1e44e45d899005de92f58b3df180b36ddaf"
+checksum = "aeb9553e62312c8756a5979254fc6d7da8bbeb5986a1e17037fab932f7037917"
 dependencies = [
  "clipboard-win",
  "log",
@@ -142,11 +142,20 @@ dependencies = [
  "objc2-foundation 0.3.2",
  "parking_lot",
  "percent-encoding",
- "windows-sys 0.60.2",
+ "windows-sys 0.61.2",
  "wl-clipboard-rs",
  "x11rb",
 ]
 
+[[package]]
+name = "arc-swap"
+version = "1.9.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "380962b3d93b99642e50b9febf72c071e97e8b32d86eae9cf4ef582bb960ae6e"
+dependencies = [
+ "rustversion",
+]
+
 [[package]]
 name = "arcstr"
 version = "1.2.0"
@@ -243,6 +252,12 @@ version = "0.22.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "72b3254f16251a8381aa12e40e3c4d2f0199f8c6508fbecb9d91f575e0fbb8c6"
 
+[[package]]
+name = "base64"
+version = "0.23.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ac07cdecf99051d9a5238b80f35af32cdeba5b336e55d957b318b50137e18da5"
+
 [[package]]
 name = "base64ct"
 version = "1.8.3"
@@ -1411,6 +1426,7 @@ dependencies = [
  "ab_glyph",
  "bytemuck",
  "chrono",
+ "crc32fast",
  "dunce",
  "flate2",
  "fs4",
@@ -1493,6 +1509,7 @@ dependencies = [
  "ab_glyph",
  "bytemuck",
  "chrono",
+ "crc32fast",
  "flate2",
  "fs4",
  "getrandom 0.3.4",
@@ -1552,7 +1569,7 @@ name = "horizon-client-render"
 version = "0.1.0"
 dependencies = [
  "ab_glyph",
- "base64",
+ "base64 0.22.1",
  "bytemuck",
  "chrono",
  "cpal",
@@ -1621,7 +1638,7 @@ dependencies = [
 name = "horizon-cosmetics"
 version = "0.1.0"
 dependencies = [
- "base64",
+ "base64 0.22.1",
  "glam",
  "png",
  "serde",
@@ -1649,7 +1666,7 @@ dependencies = [
  "serde",
  "serde_json",
  "sha2",
- "socket2 0.5.10",
+ "socket2 0.6.5",
  "spake2",
 ]
 
@@ -1754,6 +1771,14 @@ dependencies = [
  "regex",
 ]
 
+[[package]]
+name = "horizon-polytone"
+version = "0.1.0"
+dependencies = [
+ "regex",
+ "serde_json",
+]
+
 [[package]]
 name = "horizon-port-pack"
 version = "0.1.0"
@@ -1793,6 +1818,7 @@ dependencies = [
  "serde_json",
  "sha1",
  "sha2",
+ "socket2 0.5.10",
 ]
 
 [[package]]
@@ -1808,7 +1834,7 @@ dependencies = [
 name = "horizon-release-sign"
 version = "0.1.0"
 dependencies = [
- "base64",
+ "base64 0.22.1",
  "ring",
 ]
 
@@ -1817,7 +1843,7 @@ name = "horizon-server"
 version = "0.1.0"
 dependencies = [
  "ab_glyph",
- "base64",
+ "base64 0.22.1",
  "chrono",
  "getrandom 0.3.4",
  "horizon-anticheat",
@@ -1848,7 +1874,7 @@ dependencies = [
 name = "horizon-server-files"
 version = "0.1.0"
 dependencies = [
- "base64",
+ "base64 0.22.1",
  "horizon-core",
  "horizon-protocol",
  "horizon-world",
@@ -2052,12 +2078,12 @@ dependencies = [
 
 [[package]]
 name = "if-addrs"
-version = "0.13.4"
+version = "0.15.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "69b2eeee38fef3aa9b4cc5f1beea8a2444fc00e7377cafae396de3f5c2065e24"
+checksum = "c0a05c691e1fae256cf7013d99dad472dc52d5543322761f83ec8d47eab40d2b"
 dependencies = [
  "libc",
- "windows-sys 0.59.0",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -2381,9 +2407,9 @@ checksum = "f9f8bd3e56ce4dfc153cf470fffbfa98c7620958b312ca5c3a4b8d5181fd13c6"
 
 [[package]]
 name = "lru"
-version = "0.16.4"
+version = "0.18.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f66e8d5d03f609abc3a39e6f08e4164ebf1447a732906d39eb9b99b7919ef39"
+checksum = "ef9ac18847474e638e3702b76c65d4eb93428471a74778ef0f1be711717f89b5"
 
 [[package]]
 name = "lru-slab"
@@ -2482,10 +2508,11 @@ checksum = "743fb55ba31b18fb1ecef6bdc9aa2743314978ac084044301a7eee33fb99a20d"
 
 [[package]]
 name = "mysql"
-version = "27.0.0"
+version = "28.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "090068bc0a24762663338da78414148333d1ee246a7293c10a517ddf1548b291"
+checksum = "ca3de8a73b7c70f76dbcdd4b6abc9b53bbb6c4f7bd6c79d8e8a7ea2157c02487"
 dependencies = [
+ "arc-swap",
  "bufstream",
  "bytes",
  "crossbeam-queue",
@@ -2509,11 +2536,11 @@ dependencies = [
 
 [[package]]
 name = "mysql_common"
-version = "0.36.2"
+version = "0.37.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "20e7f6a15265801679ddf1ddb38fd74b4555a677a78378d4561fbe5f0b1d4d72"
+checksum = "0f27695f286b461da077b8c2f72f47feaa04ce3c3f9c0976257410e90e21208a"
 dependencies = [
- "base64",
+ "base64 0.22.1",
  "bitflags 2.13.2",
  "btoi",
  "byteorder",
@@ -3129,7 +3156,7 @@ version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ffb9bf5222606eb712d3bb30e01bc9420545b00859970897e70c682353a034f2"
 dependencies = [
- "base64",
+ "base64 0.22.1",
  "cbc",
  "cms",
  "der",
@@ -3181,11 +3208,11 @@ dependencies = [
 
 [[package]]
 name = "pem"
-version = "3.0.6"
+version = "4.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1d30c53c26bc5b31a98cd02d20f25a7c8567146caf63ed593a9d87b2775291be"
+checksum = "d354a98a3d1251555de99e8fdd8afda05573c31b82f59063a7b0a29b5527f120"
 dependencies = [
- "base64",
+ "base64 0.23.1",
  "serde_core",
 ]
 
@@ -4367,9 +4394,9 @@ checksum = "fd3ca314f692efd6c868f8408f53fe444634a845f96c028b97d35f6a1f79f0ee"
 
 [[package]]
 name = "tokio"
-version = "1.53.2"
+version = "1.53.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e95f91fcc7a621e8b030f6aa23c71fe9838ae2fb4d8118b75602a328f5144044"
+checksum = "ce3335fa71841cda333a58d7615b03901380ecf09d59b3296d21f8bbac0dde4e"
 dependencies = [
  "libc",
  "mio",
@@ -4548,7 +4575,7 @@ version = "2.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "02d1a66277ed75f640d608235660df48c8e3c19f3b4edb6a263315626cc3c01d"
 dependencies = [
- "base64",
+ "base64 0.22.1",
  "log",
  "once_cell",
  "rustls",
@@ -5237,15 +5264,6 @@ dependencies = [
  "windows-targets 0.52.6",
 ]
 
-[[package]]
-name = "windows-sys"
-version = "0.60.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f2f500e4d28234f72040990ec9d39e3a6b950f9f22d3dba18416c35882612bcb"
-dependencies = [
- "windows-targets 0.53.5",
-]
-
 [[package]]
 name = "windows-sys"
 version = "0.61.2"
@@ -5279,30 +5297,13 @@ dependencies = [
  "windows_aarch64_gnullvm 0.52.6",
  "windows_aarch64_msvc 0.52.6",
  "windows_i686_gnu 0.52.6",
- "windows_i686_gnullvm 0.52.6",
+ "windows_i686_gnullvm",
  "windows_i686_msvc 0.52.6",
  "windows_x86_64_gnu 0.52.6",
  "windows_x86_64_gnullvm 0.52.6",
  "windows_x86_64_msvc 0.52.6",
 ]
 
-[[package]]
-name = "windows-targets"
-version = "0.53.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4945f9f551b88e0d65f3db0bc25c33b8acea4d9e41163edf90dcd0b19f9069f3"
-dependencies = [
- "windows-link",
- "windows_aarch64_gnullvm 0.53.1",
- "windows_aarch64_msvc 0.53.1",
- "windows_i686_gnu 0.53.1",
- "windows_i686_gnullvm 0.53.1",
- "windows_i686_msvc 0.53.1",
- "windows_x86_64_gnu 0.53.1",
- "windows_x86_64_gnullvm 0.53.1",
- "windows_x86_64_msvc 0.53.1",
-]
-
 [[package]]
 name = "windows-threading"
 version = "0.2.1"
@@ -5324,12 +5325,6 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "32a4622180e7a0ec044bb555404c800bc9fd9ec262ec147edd5989ccd0c02cd3"
 
-[[package]]
-name = "windows_aarch64_gnullvm"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a9d8416fa8b42f5c947f8482c43e7d89e73a173cead56d044f6a56104a6d1b53"
-
 [[package]]
 name = "windows_aarch64_msvc"
 version = "0.42.2"
@@ -5342,12 +5337,6 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "09ec2a7bb152e2252b53fa7803150007879548bc709c039df7627cabbd05d469"
 
-[[package]]
-name = "windows_aarch64_msvc"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b9d782e804c2f632e395708e99a94275910eb9100b2114651e04744e9b125006"
-
 [[package]]
 name = "windows_i686_gnu"
 version = "0.42.2"
@@ -5360,24 +5349,12 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8e9b5ad5ab802e97eb8e295ac6720e509ee4c243f69d781394014ebfe8bbfa0b"
 
-[[package]]
-name = "windows_i686_gnu"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "960e6da069d81e09becb0ca57a65220ddff016ff2d6af6a223cf372a506593a3"
-
 [[package]]
 name = "windows_i686_gnullvm"
 version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0eee52d38c090b3caa76c563b86c3a4bd71ef1a819287c19d586d7334ae8ed66"
 
-[[package]]
-name = "windows_i686_gnullvm"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fa7359d10048f68ab8b09fa71c3daccfb0e9b559aed648a8f95469c27057180c"
-
 [[package]]
 name = "windows_i686_msvc"
 version = "0.42.2"
@@ -5390,12 +5367,6 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "240948bc05c5e7c6dabba28bf89d89ffce3e303022809e73deaefe4f6ec56c66"
 
-[[package]]
-name = "windows_i686_msvc"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e7ac75179f18232fe9c285163565a57ef8d3c89254a30685b57d83a38d326c2"
-
 [[package]]
 name = "windows_x86_64_gnu"
 version = "0.42.2"
@@ -5408,12 +5379,6 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "147a5c80aabfbf0c7d901cb5895d1de30ef2907eb21fbbab29ca94c5b08b1a78"
 
-[[package]]
-name = "windows_x86_64_gnu"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9c3842cdd74a865a8066ab39c8a7a473c0778a3f29370b5fd6b4b9aa7df4a499"
-
 [[package]]
 name = "windows_x86_64_gnullvm"
 version = "0.42.2"
@@ -5426,12 +5391,6 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "24d5b23dc417412679681396f2b49f3de8c1473deb516bd34410872eff51ed0d"
 
-[[package]]
-name = "windows_x86_64_gnullvm"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0ffa179e2d07eee8ad8f57493436566c7cc30ac536a3379fdf008f47f6bb7ae1"
-
 [[package]]
 name = "windows_x86_64_msvc"
 version = "0.42.2"
@@ -5444,12 +5403,6 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"
 
-[[package]]
-name = "windows_x86_64_msvc"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d6bbff5f0aada427a1e5a6da5f1f98158182f26556f345ac9e04d36d0ebed650"
-
 [[package]]
 name = "winit"
 version = "0.30.13"

Cargo.toml

@@ -37,6 +37,7 @@ members = [
     "crates/horizon-port-pack",
     "crates/horizon-shaders",
     "crates/horizon-optifine",
+    "crates/horizon-polytone",
     "crates/horizon-shader-api",
     "crates/horizon-release-sign",
     "crates/horizon-mod-deps",
@@ -47,7 +48,7 @@ resolver = "2"
 [workspace.package]
 edition = "2024"
 license = "MIT"
-rust-version = "1.85"
+rust-version = "1.95"
 
 # Ports mirror vanilla's Java signatures, index loops and nested generic types
 # one to one so they can be checked against the decompiled sources.
@@ -81,6 +82,21 @@ libmimalloc-sys = { path = "third_party/libmimalloc-sys" }
 [profile.dev]
 debug = "line-tables-only"
 
+# The native mod API is generated by a build script that parses every file of game/ with syn on
+# each gameplay edit; unoptimized that took ~6 s of every rebuild, optimized ~1.5 s.
+[profile.dev.package.horizon-mod-api-gen]
+opt-level = 3
+[profile.dev.package.syn]
+opt-level = 3
+[profile.dev.package.proc-macro2]
+opt-level = 3
+[profile.release.package.horizon-mod-api-gen]
+opt-level = 3
+[profile.release.package.syn]
+opt-level = 3
+[profile.release.package.proc-macro2]
+opt-level = 3
+
 [profile.release]
 lto = "thin"
 codegen-units = 1

README.md

@@ -49,6 +49,18 @@ Everything below is in the current release.
 
 <sub>Nightly 2026-11-05 on a Mac mini (Apple M4 Pro, Metal): vanilla's textures, no mods or shader packs, render distance 32 with distant terrain on.</sub>
 
+## Performance
+
+**Horizon draws more frames per second than Java Edition, and loads faster, on the same machine, world and path.** `tools/perf_bench.py` runs each game in turn, from a fresh world (seed 1234), waiting for the terrain and then flying it over a village, a forest, an ocean and a mountain. Measured on 2026-10-29/30 on an idle Windows 11 machine (Ryzen 7 9800X3D, RTX 5080), Horizon v0.2.97 as the launcher installs it, 1280x720 in a window, VSync off, three games per figure. Frames per second, mean of the four scenes, with the slowest 1% of frames in brackets:
+
+| Render distance | Horizon v0.2.97 | Vanilla 26.3 | Vanilla + mods |
+| --- | --- | --- | --- |
+| 8 chunks | 3,289 (1,327) | 2,437 (640) | 2,375 (709) |
+| 16 chunks | 2,074 (598) | 1,661 (375) | 1,586 (432) |
+| 32 chunks | 1,207 (333) | 1,031 (176) | 879 (264) |
+
+"Vanilla + mods" is Sodium, Lithium, FerriteCore and ImmediatelyFast. Horizon reaches the title screen in 2.9–3.2 s against vanilla's 7.5–7.7 s (the modded client's 10.8–11.1 s), loads a scene's chunks 2.9–3.8 times faster, and playing holds a steady working set of 1.1–1.7 GB against 1.9–2.9 GB. Every scene with its confidence interval and the run's load log: [the 2026-10-29 reports](benchmarks/perf/windows-9800x3d-5080-2026-10-29.md). Method, and how to measure your own machine: [docs/benchmark.md](docs/benchmark.md). [playhorizon.dev/benchmarks](https://playhorizon.dev/benchmarks) puts these runs beside a 2016 laptop, a Mac mini and a gaming desktop.
+
 ## Download
 
 Get **the Horizon launcher** from [playhorizon.dev](https://playhorizon.dev), or from [the launcher releases](https://github.com/horizon-rust/horizon/releases?q=launcher&expanded=true):

ROADMAP.md

@@ -410,16 +410,6 @@ The panel's later features (bans, worlds, server.properties import, logs and cra
 
 </details>
 
-#### Ely.by and other sign-in providers
-
-Sign in with other account providers, such as Ely.by or any Yggdrasil-compatible one, beside Microsoft.
-
-<details><summary>Technical</summary>
-
-Issue [#1270](https://github.com/horizon-rust/horizon/issues/1270) asks for Ely.by and Yggdrasil-compatible servers with an account selector in the launcher. It builds on the Microsoft sign-in ([docs/microsoft-account.md](docs/microsoft-account.md)).
-
-</details>
-
 #### Join servers on older versions
 
 Join servers that run older Minecraft versions, such as 1.21 or 1.8 PvP servers, from Horizon.

THIRD_PARTY_NOTICES.md

@@ -1,5 +1,46 @@
 # Third-party notices
 
+## Code removed for its license
+
+Horizon once shipped three pieces of code under MIT that came from projects whose licenses don't allow that. All
+three are gone from main. They are listed here for anyone who holds an older commit, tag or release: in those
+versions, that code is not covered by Horizon's MIT license. It stays under its authors' copyright and its original
+license.
+
+- **Shader packs written from Iris's source.** `crates/horizon-shaderpack` and the render stages that used it were
+  written from the source of [Iris](https://github.com/IrisShaders/Iris) (LGPL-3.0, copyright the Iris contributors).
+  They were added from 15 October 2026 (`b22583d057`), shipped in the game releases `v2026.10.16.02` to `v0.2.46`,
+  and were removed on 24 October 2026 ([#1561](https://github.com/horizon-rust/horizon/pull/1561)) after a developer
+  of Iris showed us. Shader packs came back in `crates/horizon-shaders`, first written from a description of the
+  pack format.
+- **Math functions translated from OpenJDK.** In `crates/horizon-core/src/jmath.rs`, `fdlibm::{log, log10, cbrt,
+  hypot}` were translated from OpenJDK's `java/lang/FdLibm.java` and `round_f32` from its `java/lang/Math.java`
+  (GPL-2.0 with the Classpath Exception), and `aarch64::{sin, cos}` from HotSpot's `macroAssembler_aarch64_trig.cpp`
+  (GPL-2.0); copyright Oracle and/or its affiliates, and Cavium for that file. The `fdlibm` and `aarch64` functions
+  were added on 13 October 2026 (`558d140fca`, first released in `v2026.10.13`). `round_f32` was added on 14 October
+  2026 as `java_round` in `crates/horizon-client/src/mipmap.rs` (`95db0fce9d`) and moved into `jmath.rs` on 3
+  November ([#7770](https://github.com/horizon-rust/horizon/pull/7770)). All of them were replaced in
+  [#11944](https://github.com/horizon-rust/horizon/pull/11944) by code written without OpenJDK's sources, from Sun's
+  fdlibm C sources, the Java SE API documentation and a description of the behaviour, and checked against a JVM
+  ([#6741](https://github.com/horizon-rust/horizon/issues/6741)).
+- **Java's `HashMap` translated from OpenJDK.** `crates/horizon-world/src/java_hash_map.rs`, which reproduces the
+  iteration order of `java.util.HashMap`, was translated from OpenJDK's `java/util/HashMap.java` (GPL-2.0 with the
+  Classpath Exception; copyright Oracle and/or its affiliates). It was added on 7 October 2026 (`118e93ea51` and
+  `194db0dbb4`, first released in `v2026.10.12`). It was replaced in
+  [#12043](https://github.com/horizon-rust/horizon/pull/12043) by code written without OpenJDK's sources, from a
+  description of the behaviour, the Java SE API documentation and the textbook red-black tree, and checked against a
+  JVM ([#6741](https://github.com/horizon-rust/horizon/issues/6741)).
+
+## Catnip / Ponder
+
+`crates/horizon-client-render/src/fluid_render.rs` translates the still-fluid face tiling and
+UV rules of Catnip's `FluidRenderHelper` from Ponder 1.0.82 for Minecraft 1.21.1
+(`net.createmod.ponder:ponder-neoforge:1.0.82+mc1.21.1`). Copyright (c) 2022 The Create Team,
+licensed under MIT (`LICENSE_Ponder` in that artifact); the full license heads the Rust file.
+The native renderer uses Horizon's own block-sprite arrays, pose and light packing. The
+development-only oracle calls the unchanged helper from the player's local artifact. No
+original classes, game shaders, textures or prepared resources are distributed here.
+
 ## wgpu-hal
 
 `third_party/wgpu-hal` is [wgpu-hal](https://github.com/gfx-rs/wgpu) 30.0.1 by the gfx-rs
@@ -212,3 +253,56 @@ 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.
 ```
+
+## Just Enough Items
+
+The Recipes GUI sprites and settings icon under `crates/horizon-client-render/src/jei_recipes` are from
+[Just Enough Items 31.17.0.108](https://github.com/mezz/JustEnoughItems/tree/0371fa6fafa14635a356019e4604f5580b26a34f)
+by mezz and contributors, under the MIT license in that directory (`LICENSE.txt`).
+
+## Flywheel native model directional shading
+
+The two-light diffuse expression and transformed-normal policy in
+`terrain.wgsl`'s native model entries follow Flywheel 1.0.6
+(`internal/diffuse.glsl`, `instance/transformed.vert`, `internal/common.vert`).
+No Flywheel classes, compiled shaders or original model/texture assets are bundled.
+
+Copyright (c) 2021-2024 Jozufozu
+
+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.
+
+## fdlibm
+
+`crates/horizon-core/src/jmath/fdlibm.rs` and the `fdlibm_asin`, `fdlibm_atan` and
+`fdlibm_atan2` functions in `crates/horizon-core/src/geometry/trig.rs` are Rust ports of
+[fdlibm](https://www.netlib.org/fdlibm/) 5.3, Sun's freely distributable math library, whose
+results the Java SE API specifies for `StrictMath`. `fdlibm.rs` ports `e_log.c`, `e_log10.c`,
+`s_cbrt.c` and `e_hypot.c`, and, with fused multiply-adds, `s_sin.c`, `s_cos.c`, `k_sin.c`,
+`k_cos.c` and `e_rem_pio2.c`; `trig.rs` ports `e_asin.c`, `s_atan.c` and `e_atan2.c`. This
+notice also heads both files:
+
+```
+Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+
+Developed at SunSoft, a Sun Microsystems, Inc. business.
+Permission to use, copy, modify, and distribute this
+software is freely granted, provided that this notice
+is preserved.
+```

crates/cargo-horizon-mod/Cargo.toml

@@ -3,7 +3,7 @@ name = "cargo-horizon-mod"
 version = "0.1.0"
 edition.workspace = true
 license.workspace = true
-rust-version = "1.86"
+rust-version.workspace = true
 description = "cargo horizon-mod new/build/run/check: make Horizon content mods (docs/mods.md)"
 
 # `cargo binstall --git https://github.com/horizon-rust/horizon cargo-horizon-mod` (#2120) reads this: the archive

crates/horizon-anticheat/Cargo.toml

@@ -3,7 +3,7 @@ name = "horizon-anticheat"
 version = "0.1.0"
 edition.workspace = true
 license.workspace = true
-rust-version = "1.85"
+rust-version.workspace = true
 description = "The dedicated server's anticheat: its [anticheat] settings, violation levels and the checks' rules, with no game state (docs/anticheat.md)"
 
 [dependencies]

crates/horizon-assets/examples/support/mod.rs

@@ -34,7 +34,10 @@ pub fn element(v: &Element) -> Value {
         .collect();
     json!({"from":bits(v.from),"to":bits(v.to),"faces":faces,"rotation":v.rotation.as_ref().map(rotation),"shade":v.shade_direction_override.map(Direction::name),"light":v.light_emission})
 }
-#[allow(dead_code)] // Shared by fixtures which normalize different model stages.
+#[allow(
+    dead_code,
+    reason = "shared by fixtures which normalize different model stages"
+)]
 pub fn model(v: &CuboidModel) -> Value {
     let textures: BTreeMap<_, _> = v
         .textures

crates/horizon-assets/src/bake.rs

@@ -34,6 +34,8 @@ pub struct ModelQuad {
 /// NeoForge's `render_type` names.
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub enum RenderType {
+    /// A declared render type unknown to this baker; distinct from an absent default.
+    Unsupported,
     Solid,
     Cutout,
     CutoutMipped,
@@ -234,7 +236,10 @@ fn bake_into(
     skip_flat: bool,
     output: &mut Vec<ModelQuad>,
 ) -> Result<()> {
-    let render_type = model.render_type.as_deref().and_then(RenderType::by_name);
+    let render_type = model
+        .render_type
+        .as_deref()
+        .map(|name| RenderType::by_name(name).unwrap_or(RenderType::Unsupported));
     for element in model.elements() {
         let element = element
             .as_ref()
@@ -292,7 +297,10 @@ fn bake_obj(
     transform: BlockModelTransform,
     output: &mut Vec<ModelQuad>,
 ) -> Result<()> {
-    let render_type = model.render_type.as_deref().and_then(RenderType::by_name);
+    let render_type = model
+        .render_type
+        .as_deref()
+        .map(|name| RenderType::by_name(name).unwrap_or(RenderType::Unsupported));
     for face in obj.faces.iter().filter(|f| !hidden.contains(&f.object)) {
         let slot = match obj.materials.get(&face.material) {
             Some(MtlTexture::Sprite(sprite)) => {

crates/horizon-assets/src/blockstate.rs

@@ -179,19 +179,19 @@ impl Condition {
         let fields = object(raw)?;
         if fields.len() == 1 {
             for name in ["OR", "AND"] {
-                if let Some(raw) = fields.get(name) {
-                    if let Ok(values) = array(raw).and_then(|values| {
+                if let Some(raw) = fields.get(name)
+                    && let Ok(values) = array(raw).and_then(|values| {
                         values
                             .into_iter()
                             .map(Self::decode)
                             .collect::<Result<Vec<_>>>()
-                    }) {
-                        return Ok(if name == "OR" {
-                            Self::Or(values)
-                        } else {
-                            Self::And(values)
-                        });
-                    }
+                    })
+                {
+                    return Ok(if name == "OR" {
+                        Self::Or(values)
+                    } else {
+                        Self::And(values)
+                    });
                 }
             }
         }

crates/horizon-assets/src/item_model.rs

@@ -917,6 +917,46 @@ impl NumericProperty {
 /// (`None` removes a prototype component).
 pub type Components = BTreeMap<String, Value>;
 
+/// A stack's components read in place: its patch first, then its item's defaults. Reading one copies
+/// nothing, where [`ItemModels::components`] clones the defaults for a stack with a patch (an enchanted
+/// sword's are a few dozen JSON values, on every draw of it).
+#[derive(Clone, Copy)]
+pub struct ComponentsView<'a> {
+    prototype: &'a Components,
+    patch: &'a BTreeMap<String, Option<Value>>,
+}
+
+impl<'a> ComponentsView<'a> {
+    pub fn get(&self, key: &str) -> Option<&'a Value> {
+        match self.patch.get(key) {
+            Some(patched) => patched.as_ref(),
+            None => self.prototype.get(key),
+        }
+    }
+    pub fn contains_key(&self, key: &str) -> bool {
+        self.get(key).is_some()
+    }
+    /// Components with no patch: `components` as they are.
+    pub fn of(components: &'a Components) -> Self {
+        static NO_PATCH: BTreeMap<String, Option<Value>> = BTreeMap::new();
+        Self {
+            prototype: components,
+            patch: &NO_PATCH,
+        }
+    }
+    /// The merged map, for what needs one whole.
+    pub fn to_map(&self) -> Components {
+        let mut out = self.prototype.clone();
+        for (key, value) in self.patch {
+            match value {
+                Some(v) => out.insert(key.clone(), v.clone()),
+                None => out.remove(key),
+            };
+        }
+        out
+    }
+}
+
 /// An item stack as the resolver reads it.
 #[derive(Clone, Debug, Default, PartialEq)]
 pub struct StackView {
@@ -1087,14 +1127,15 @@ impl ItemModels {
         if stack.patch.is_empty() {
             return std::borrow::Cow::Borrowed(prototype);
         }
-        let mut out = prototype.clone();
-        for (key, value) in &stack.patch {
-            match value {
-                Some(v) => out.insert(key.clone(), v.clone()),
-                None => out.remove(key),
-            };
+        std::borrow::Cow::Owned(self.components_view(stack).to_map())
+    }
+    /// The stack's components, read in place (see [`ComponentsView`]).
+    pub fn components_view<'a>(&'a self, stack: &'a StackView) -> ComponentsView<'a> {
+        static NONE: Components = BTreeMap::new();
+        ComponentsView {
+            prototype: self.prototypes.get(&stack.item).unwrap_or(&NONE),
+            patch: &stack.patch,
         }
-        std::borrow::Cow::Owned(out)
     }
     /// `ItemModelResolver.updateForTopItem`.
     pub fn resolve(&self, stack: &StackView, ctx: &Context, env: &dyn ItemEnv) -> ResolvedItem {
@@ -1112,7 +1153,7 @@ impl ItemModels {
         ctx: &Context,
         env: &dyn ItemEnv,
     ) {
-        let components = self.components(stack);
+        let components = self.components_view(stack);
         let Some(Value::String(model_id)) = components.get("minecraft:item_model") else {
             return;
         };
@@ -1122,7 +1163,7 @@ impl ItemModels {
         let mut state = Resolve {
             models: self,
             stack,
-            components: &components,
+            components,
             ctx,
             env,
         };
@@ -1140,7 +1181,7 @@ impl ItemModels {
         self.properties(stack).2
     }
     fn properties(&self, stack: &StackView) -> (bool, bool, f32) {
-        match self.components(stack).get("minecraft:item_model") {
+        match self.components_view(stack).get("minecraft:item_model") {
             Some(Value::String(id)) => identifier(id)
                 .ok()
                 .and_then(|id| self.definitions.get(&id))
@@ -1159,7 +1200,7 @@ impl ItemModels {
 struct Resolve<'a> {
     models: &'a ItemModels,
     stack: &'a StackView,
-    components: &'a Components,
+    components: ComponentsView<'a>,
     ctx: &'a Context<'a>,
     env: &'a dyn ItemEnv,
 }
@@ -1455,9 +1496,9 @@ impl Resolve<'_> {
     fn numeric(&self, property: &NumericProperty) -> f32 {
         let owner = self.ctx.owner;
         match property {
-            NumericProperty::BundleFullness => {
-                self.env.bundle_fullness(self.stack, self.components)
-            }
+            NumericProperty::BundleFullness => self
+                .env
+                .bundle_fullness(self.stack, &self.components.to_map()),
             NumericProperty::Compass {
                 wobble,
                 target,

crates/horizon-assets/src/item_model/component_predicate.rs

@@ -63,7 +63,7 @@ pub(super) fn decode(m: &Map<String, Value>) -> Result<Value> {
 /// with a matching level. An empty predicate list still needs the component.
 pub(super) fn matches(
     predicate: &Value,
-    components: &Components,
+    components: ComponentsView<'_>,
     env: &dyn ItemEnv,
 ) -> Option<bool> {
     let (id, expected) = predicate.as_object()?.iter().next()?;
@@ -143,13 +143,17 @@ mod tests {
             json!({"minecraft:density":0}),
         )]);
         assert_eq!(
-            matches(&json!({"minecraft:enchantments":[{}]}), &components, &NoEnv),
+            matches(
+                &json!({"minecraft:enchantments":[{}]}),
+                ComponentsView::of(&components),
+                &NoEnv
+            ),
             Some(true)
         );
         assert_eq!(
             matches(
                 &json!({"minecraft:enchantments":[{"enchantments":"minecraft:density"}]}),
-                &components,
+                ComponentsView::of(&components),
                 &NoEnv
             ),
             Some(false)
@@ -166,12 +170,21 @@ mod tests {
             "minecraft:enchantments".into(),
             json!({"minecraft:density":3}),
         )]);
-        assert_eq!(matches(&predicate, &components, &Tags), Some(true));
-        assert_eq!(matches(&predicate, &components, &NoEnv), Some(false));
+        assert_eq!(
+            matches(&predicate, ComponentsView::of(&components), &Tags),
+            Some(true)
+        );
+        assert_eq!(
+            matches(&predicate, ComponentsView::of(&components), &NoEnv),
+            Some(false)
+        );
         components.insert(
             "minecraft:enchantments".into(),
             json!({"minecraft:density":2}),
         );
-        assert_eq!(matches(&predicate, &components, &Tags), Some(false));
+        assert_eq!(
+            matches(&predicate, ComponentsView::of(&components), &Tags),
+            Some(false)
+        );
     }
 }

crates/horizon-assets/src/item_model/tests.rs

@@ -1,4 +1,5 @@
 use super::*;
+use serde_json::json;
 
 #[test]
 fn identifier_adds_default_namespace() {
@@ -111,3 +112,49 @@ fn custom_condition_validates_its_name_and_both_branches() {
     assert!(matches!(node("example:charged", empty).unwrap(),
         ItemModelNode::Condition { property: ConditionProperty::Custom(name), .. } if name == "example:charged"));
 }
+
+#[test]
+fn a_patched_stack_reads_its_patch_over_its_items_defaults() {
+    let mut models = ItemModels::default();
+    models.prototypes.insert(
+        "minecraft:diamond_sword".into(),
+        Components::from_iter([
+            (
+                "minecraft:item_model".into(),
+                json!("minecraft:diamond_sword"),
+            ),
+            ("minecraft:max_damage".into(), json!(1561)),
+            ("minecraft:rarity".into(), json!("common")),
+        ]),
+    );
+    let mut stack = StackView::new("minecraft:diamond_sword", 1);
+    stack.patch.insert(
+        "minecraft:enchantments".into(),
+        Some(json!({"minecraft:sharpness": 5})),
+    );
+    stack
+        .patch
+        .insert("minecraft:rarity".into(), Some(json!("rare")));
+    stack.patch.insert("minecraft:max_damage".into(), None);
+    let view = models.components_view(&stack);
+    assert_eq!(view.get("minecraft:rarity"), Some(&json!("rare")));
+    assert_eq!(view.get("minecraft:max_damage"), None, "a removed default");
+    assert_eq!(
+        view.get("minecraft:item_model"),
+        Some(&json!("minecraft:diamond_sword"))
+    );
+    assert!(view.contains_key("minecraft:enchantments"));
+    assert!(!view.contains_key("minecraft:custom_name"));
+    // Every key reads as the merged map has it.
+    let merged = models.components(&stack);
+    for key in [
+        "minecraft:rarity",
+        "minecraft:max_damage",
+        "minecraft:item_model",
+        "minecraft:enchantments",
+        "minecraft:custom_name",
+    ] {
+        assert_eq!(view.get(key), merged.get(key), "{key}");
+    }
+    assert_eq!(view.to_map(), *merged);
+}

crates/horizon-assets/src/resolve.rs

@@ -777,6 +777,23 @@ mod tests {
         );
     }
     #[test]
+    fn an_unknown_declared_render_type_remains_distinct_from_absent() {
+        let json = LIGHTS.replace("minecraft:cutout", "fixture:custom_material");
+        let library = library(&[("block/custom", &json)]);
+        let model = library.resolve("block/custom").unwrap();
+        let quads = crate::bake::bake_block_model(
+            &model,
+            crate::bake::BlockModelTransform::new([0; 3], false),
+        )
+        .unwrap();
+        assert!(!quads.is_empty());
+        assert!(
+            quads
+                .iter()
+                .all(|q| q.render_type == Some(crate::bake::RenderType::Unsupported))
+        );
+    }
+    #[test]
     fn render_type_comes_from_the_leaf_most_model_and_loses_its_prefix() {
         let library = library(&[
             ("block/base", r#"{"render_type":"translucent"}"#),

crates/horizon-bench/Cargo.toml

@@ -2,6 +2,7 @@
 name = "horizon-bench"
 version = "0.1.0"
 edition = "2021"
+rust-version.workspace = true
 license = "MIT"
 description = "The benchmark report format (docs/benchmark-report.md), shared by the game, the launcher and the upload"
 

crates/horizon-bots/src/main.rs

@@ -694,7 +694,7 @@ fn costly(
         Behaviour::FloodUse => {
             // A block within reach: place stone there, or break what is there.
             let at = [0, 1, 2].map(|k| block[k] + (random.unit() * 7.0) as i32 - 3);
-            if i % 2 == 0 {
+            if i.is_multiple_of(2) {
                 play::Serverbound::UseItemOn(play::UseItemOn {
                     hand: 0,
                     pos: at,
@@ -723,7 +723,7 @@ fn costly(
             carried: None,
         }),
         Behaviour::FloodSuggest => {
-            let text = if i % 2 == 0 {
+            let text = if i.is_multiple_of(2) {
                 "/"
             } else {
                 LONG_COMMAND.as_str()
@@ -1555,10 +1555,10 @@ fn main() {
     });
     if o.report.as_deref() == Some("-") {
         println!("{summary:#}");
-    } else if let Some(path) = &o.report {
-        if let Err(e) = std::fs::write(path, format!("{summary:#}\n")) {
-            eprintln!("horizon-bots: {path}: {e}");
-        }
+    } else if let Some(path) = &o.report
+        && let Err(e) = std::fs::write(path, format!("{summary:#}\n"))
+    {
+        eprintln!("horizon-bots: {path}: {e}");
     }
     let errors: Vec<String> = bots
         .iter()

crates/horizon-chat-filter/Cargo.toml

@@ -3,7 +3,7 @@ name = "horizon-chat-filter"
 version = "0.1.0"
 edition.workspace = true
 license.workspace = true
-rust-version = "1.88"
+rust-version.workspace = true
 description = "The dedicated server's chat filter: its [chat_filter] settings, the slur list's matcher and the mutes, with no game state (docs/chat-filter.md)"
 
 [dependencies]

crates/horizon-client-core/Cargo.toml

@@ -3,7 +3,7 @@ name = "horizon-client-core"
 version = "0.1.0"
 edition.workspace = true
 license.workspace = true
-rust-version = "1.90"
+rust-version.workspace = true
 description = "The client's lowest layer: chat text and translations, SNBT and NBT paths, the scoreboard, boss bars, game rules and the registry and particle tables commands name"
 
 [dependencies]

crates/horizon-client-core/src/registries.rs

@@ -275,6 +275,25 @@ impl Registries {
                 .clone_from(&e.advancement_criteria);
         }
     }
+    /// Add the damage catalog's types ([`Self::damage_types`]: content mods'
+    /// and the world's packs' with vanilla's) to the commands'
+    /// `minecraft:damage_type` ids, which the export lists for vanilla alone.
+    /// `ResourceArgument` looks a type up in the server's registries, so
+    /// `/damage` takes every type the world has. The export's tags stay. The
+    /// ids are replaced, not extended: `by_registry` outlives a world, and a
+    /// pack's type must not stay accepted in the next world opened.
+    pub fn sync_damage_type_ids(&mut self) {
+        if self.damage_types.is_empty() {
+            return;
+        }
+        let mut ids = self.damage_types.clone();
+        ids.sort();
+        ids.dedup();
+        self.by_registry
+            .entry("minecraft:damage_type".into())
+            .or_default()
+            .ids = ids;
+    }
     /// The element ids of a registry (sorted).
     pub fn ids(&self, registry: &str) -> &[String] {
         if let Some(r) = self.by_registry.get(registry) {
@@ -312,3 +331,49 @@ impl Registries {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::Registries;
+
+    /// A content mod's damage type joins vanilla's in the commands' ids, the
+    /// export's tags stay, and a second world open lists each type once.
+    #[test]
+    fn damage_type_ids_take_the_catalogs_types() {
+        let export = Registries::from_export(&serde_json::json!({
+            "by_registry": {"minecraft:damage_type": {
+                "ids": ["minecraft:fall", "minecraft:magic"],
+                "tags": ["minecraft:is_fall"],
+            }},
+        }));
+        let mut reg = Registries {
+            damage_types: vec![
+                "minecraft:magic".into(),
+                "example:test".into(),
+                "minecraft:fall".into(),
+            ],
+            ..Registries::default()
+        };
+        reg.fill_from_exported(&export);
+        assert_eq!(
+            reg.ids("minecraft:damage_type"),
+            ["minecraft:fall", "minecraft:magic"],
+            "the export alone lists vanilla's types"
+        );
+        for _ in 0..2 {
+            reg.sync_damage_type_ids();
+            assert_eq!(
+                reg.ids("minecraft:damage_type"),
+                ["example:test", "minecraft:fall", "minecraft:magic"]
+            );
+            assert_eq!(reg.tags("minecraft:damage_type"), ["minecraft:is_fall"]);
+        }
+        // The next world, without the pack: its type is no longer accepted.
+        reg.damage_types = vec!["minecraft:fall".into(), "minecraft:magic".into()];
+        reg.sync_damage_type_ids();
+        assert_eq!(
+            reg.ids("minecraft:damage_type"),
+            ["minecraft:fall", "minecraft:magic"]
+        );
+    }
+}

crates/horizon-client-input/Cargo.toml

@@ -3,7 +3,7 @@ name = "horizon-client-input"
 version = "0.1.0"
 edition.workspace = true
 license.workspace = true
-rust-version = "1.90"
+rust-version.workspace = true
 description = "The client's input layer: key bindings and their names, mouse, controllers, clipboard and window options"
 
 [dependencies]

crates/horizon-client-input/src/gamepad.rs

@@ -490,6 +490,37 @@ impl GlyphStyle {
     }
 }
 
+/// How much the gameplay guide says.
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Default)]
+pub enum GuideDetail {
+    #[default]
+    Full,
+    /// Only what can be done to what's in front of the player or under the crosshair.
+    Basic,
+    Off,
+}
+impl GuideDetail {
+    pub const ALL: [GuideDetail; 3] = [GuideDetail::Full, GuideDetail::Basic, GuideDetail::Off];
+
+    /// The name in `horizon-controller.txt`.
+    pub fn name(self) -> &'static str {
+        match self {
+            GuideDetail::Full => "full",
+            GuideDetail::Basic => "basic",
+            GuideDetail::Off => "off",
+        }
+    }
+
+    /// Reads a name, or the `true` and `false` this option first saved. Anything else is full.
+    pub fn parse(value: &str) -> Self {
+        match value {
+            "basic" => GuideDetail::Basic,
+            "off" | "false" => GuideDetail::Off,
+            _ => GuideDetail::Full,
+        }
+    }
+}
+
 /// The on-screen keyboard A opens on a text field in focus mode.
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Default)]
 pub enum TextKeyboard {
@@ -537,6 +568,8 @@ pub fn steam_keyboard(choice: TextKeyboard) -> bool {
 pub struct PadSettings {
     pub enabled: bool,
     pub vibration: bool,
+    /// The pad keeps driving the game while its window has no focus.
+    pub play_in_background: bool,
     /// A DualSense's triggers push back (Horizon's; docs/controllers.md).
     pub adaptive_triggers: bool,
     pub lightbar: Lightbar,
@@ -556,6 +589,8 @@ pub struct PadSettings {
     /// by default on the Switch only.
     pub nintendo_letters: bool,
     pub keyboard: TextKeyboard,
+    /// The gameplay guide: what the buttons do now, in the HUD's corners while the pad plays.
+    pub guide_detail: GuideDetail,
     /// Menu pointer multiplier, scroll lines/second, and repeat times in seconds.
     pub pointer_speed: f32,
     pub scroll_speed: f32,
@@ -569,6 +604,7 @@ impl Default for PadSettings {
         Self {
             enabled: true,
             vibration: true,
+            play_in_background: false,
             adaptive_triggers: true,
             lightbar: Lightbar::Health,
             look_sensitivity: 0.5,
@@ -581,6 +617,7 @@ impl Default for PadSettings {
             glyphs: GlyphStyle::Auto,
             nintendo_letters: cfg!(target_os = "horizon"),
             keyboard: TextKeyboard::Auto,
+            guide_detail: GuideDetail::Full,
             pointer_speed: 1.0,
             scroll_speed: 12.0,
             repeat_delay: 0.35,
@@ -635,6 +672,7 @@ impl PadSettings {
             match key.trim() {
                 "enabled" => s.enabled = flag(s.enabled),
                 "vibration" => s.vibration = flag(s.vibration),
+                "playInBackground" => s.play_in_background = flag(s.play_in_background),
                 "adaptiveTriggers" => s.adaptive_triggers = flag(s.adaptive_triggers),
                 "lightbar" => s.lightbar = Lightbar::parse(value),
                 "lookSensitivity" => s.look_sensitivity = unit(s.look_sensitivity),
@@ -649,6 +687,7 @@ impl PadSettings {
                 "glyphs" => s.glyphs = GlyphStyle::parse(value),
                 "nintendoLetters" => s.nintendo_letters = flag(s.nintendo_letters),
                 "keyboard" => s.keyboard = TextKeyboard::parse(value),
+                "gameplayGuide" => s.guide_detail = GuideDetail::parse(value),
                 "pointerSpeed" => s.pointer_speed = bounded(s.pointer_speed, 0.25, 3.0),
                 "scrollSpeed" => s.scroll_speed = bounded(s.scroll_speed, 1.0, 36.0),
                 "repeatDelay" => s.repeat_delay = bounded(s.repeat_delay, 0.1, 1.0),
@@ -706,7 +745,8 @@ impl PadSettings {
             self.keyboard.name(),
         );
         text.push_str(&format!(
-            "pointerSpeed:{}\nscrollSpeed:{}\nrepeatDelay:{}\nrepeatInterval:{}\n",
+            "gameplayGuide:{}\npointerSpeed:{}\nscrollSpeed:{}\nrepeatDelay:{}\nrepeatInterval:{}\n",
+            self.guide_detail.name(),
             self.pointer_speed, self.scroll_speed, self.repeat_delay, self.repeat_interval,
         ));
         for (action, button) in &self.bindings {
@@ -715,6 +755,10 @@ impl PadSettings {
                 button.map_or("none", Button::name)
             ));
         }
+        text.push_str(&format!(
+            "playInBackground:{}\n",
+            bool_text(self.play_in_background)
+        ));
         text.push_str("bindLayout:1\n");
         text
     }
@@ -786,7 +830,8 @@ pub fn stick_axes(
     {
         // Default map: RightStickX is the stick's Y, LeftZ its X; RightStickY
         // is the right trigger and must not drive look.
-        (left, [left_z, right[0]])
+        // gilrs turns over only the axes it calls Y, and this Y is on one it doesn't.
+        (left, [left_z, -right[0]])
     } else {
         (left, right)
     }
@@ -1752,6 +1797,15 @@ bind_key.hotbar.2:north
         }
     }
 
+    #[test]
+    fn playing_in_the_background_is_off_until_saved_on() {
+        assert!(!PadSettings::parse("vibration:false\n").play_in_background);
+        let mut on = PadSettings::default();
+        assert!(!on.play_in_background);
+        on.play_in_background = true;
+        assert!(PadSettings::parse(&on.serialize()).play_in_background);
+    }
+
     #[test]
     fn a_file_from_before_these_defaults_keeps_its_buttons() {
         // Saved settings that never bound D-pad down: it stays on the advancements.
@@ -1793,6 +1847,7 @@ bind_key.hotbar.2:north
         s.look_sensitivity = 0.75;
         s.glyphs = GlyphStyle::PlayStation;
         s.nintendo_letters = !s.nintendo_letters;
+        s.guide_detail = GuideDetail::Basic;
         let text = s.serialize();
         assert!(text.contains(&format!("nintendoLetters:{}\n", s.nintendo_letters)));
         assert!(text.contains("bind_key.jump:east\n"));
@@ -1820,7 +1875,11 @@ bind_key.hotbar.2:north
             false,
         );
         assert_eq!(left, [0.2, 0.3]);
-        assert_eq!(right, [-0.5, 0.7], "X from LeftZ, Y from RightStickX");
+        assert_eq!(
+            right,
+            [-0.5, -0.7],
+            "X from LeftZ, Y from RightStickX, turned over"
+        );
         let kept = stick_axes(
             [0.2, 0.3],
             [0.7, -0.9],

crates/horizon-client-input/src/gameplay_guide.rs

@@ -0,0 +1,962 @@
+//! The gameplay guide: what the buttons do right now, in the corners of the HUD while a pad plays
+//! and of an inventory it drives (Horizon's; vanilla has no gamepad input). The game reads the facts
+//! from its own hit results and capabilities (`game/pad/guide.rs`); this turns them into rows, and
+//! places the rows around what was drawn.
+use crate::gamepad::{Button, GuideDetail, PadSettings, Rect};
+
+/// What a use does, by what takes it.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum Verb {
+    Use,
+    Open,
+    Ride,
+    Trade,
+    Feed,
+    Place,
+    Eat,
+    Drink,
+    Shoot,
+    Load,
+    Throw,
+    Raise,
+    Equip,
+    Fish,
+    Zoom,
+    Boost,
+}
+impl Verb {
+    fn caption(self) -> &'static str {
+        match self {
+            Verb::Use => "horizon.controller.guide.use",
+            Verb::Open => "horizon.controller.guide.open",
+            Verb::Ride => "horizon.controller.guide.ride",
+            Verb::Trade => "horizon.controller.guide.trade",
+            Verb::Feed => "horizon.controller.guide.feed",
+            Verb::Place => "horizon.controller.guide.place",
+            Verb::Eat => "horizon.controller.guide.eat",
+            Verb::Drink => "horizon.controller.guide.drink",
+            Verb::Shoot => "horizon.controller.guide.shoot",
+            Verb::Load => "horizon.controller.guide.load",
+            Verb::Throw => "horizon.controller.guide.throw",
+            Verb::Raise => "horizon.controller.guide.raise",
+            Verb::Equip => "horizon.controller.guide.equip",
+            Verb::Fish => "horizon.controller.guide.fish",
+            Verb::Zoom => "horizon.controller.guide.zoom",
+            Verb::Boost => "horizon.controller.guide.boost",
+        }
+    }
+}
+
+/// `Minecraft.hitResult`, with what each button would do to it.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
+pub enum Target {
+    #[default]
+    None,
+    Block {
+        breakable: bool,
+        /// The block takes the use before the held item gets its turn.
+        takes: Option<Verb>,
+    },
+    Entity {
+        attackable: bool,
+        takes: Option<Verb>,
+    },
+}
+
+/// An item in use, by what letting go of it does.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum Active {
+    Shoot,
+    Throw,
+    Stop,
+}
+
+/// What the guide knows of the player this moment.
+#[derive(Clone, Copy, Debug, Default, PartialEq)]
+pub struct Facts {
+    pub spectator: bool,
+    pub target: Target,
+    /// What `Item.use` does on the target or in the air: the main hand's, else the off hand's.
+    pub item_use: Option<Verb>,
+    /// Pick Block finds something it can select or, in creative, add.
+    pub can_pick: bool,
+    pub using: Option<Active>,
+    /// `LocalPlayer.isHandsBusy`: paddling a boat.
+    pub hands_busy: bool,
+    pub riding: bool,
+    /// The vehicle jumps when told (a saddled horse).
+    pub vehicle_jumps: bool,
+    pub on_ground: bool,
+    pub in_water: bool,
+    pub flying: bool,
+    pub may_fly: bool,
+    pub gliding: bool,
+    /// In the air with a glider on: a jump would start gliding.
+    pub can_glide: bool,
+    /// Sneaking that the button latched, so the next press stands up.
+    pub sneak_latched: bool,
+    pub can_sprint: bool,
+    pub main_hand_item: bool,
+    pub off_hand_item: bool,
+}
+
+/// One button's line: the button and the translation key of what it does.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub struct Row {
+    /// Shown before `button`: held with it, or its other half (LB and RB for pages).
+    pub with: Option<Button>,
+    pub button: Button,
+    pub caption: &'static str,
+}
+impl Row {
+    fn new(button: Button, caption: &'static str) -> Self {
+        Row {
+            with: None,
+            button,
+            caption,
+        }
+    }
+    fn pair(with: Button, button: Button, caption: &'static str) -> Self {
+        Row {
+            with: Some(with),
+            button,
+            caption,
+        }
+    }
+}
+
+/// The two columns, most useful row first.
+#[derive(Clone, Debug, Default, PartialEq, Eq)]
+pub struct Guide {
+    /// Top left: movement and the player's own actions.
+    pub left: Vec<Row>,
+    /// Top right: break, use and pick block.
+    pub right: Vec<Row>,
+}
+
+impl Guide {
+    /// The rows this detail keeps. Basic is the right column: what the buttons do to what's in
+    /// front of the player, or the plain face buttons in an inventory.
+    pub fn at_detail(self, detail: GuideDetail) -> Self {
+        match detail {
+            GuideDetail::Full => self,
+            GuideDetail::Basic => Guide {
+                left: Vec::new(),
+                right: self.right,
+            },
+            GuideDetail::Off => Guide {
+                left: Vec::new(),
+                right: Vec::new(),
+            },
+        }
+    }
+}
+
+/// The rows for these facts on these bindings. An unbound action has no row, and neither has one
+/// on Start, which is always pause.
+pub fn resolve(facts: &Facts, settings: &PadSettings) -> Guide {
+    let row = |action: &str, caption: Option<&'static str>| {
+        let button = settings
+            .binding(action)
+            .filter(|button| *button != Button::Start)?;
+        Some(Row::new(button, caption?))
+    };
+    let player = !facts.spectator;
+    let any_item = facts.main_hand_item || facts.off_hand_item;
+    Guide {
+        left: [
+            row("key.jump", jump_caption(facts)),
+            row("key.sneak", sneak_caption(facts)),
+            row("key.sprint", facts.can_sprint.then_some("key.sprint")),
+            row("key.inventory", player.then_some("key.inventory")),
+            row(
+                "key.drop",
+                (player && facts.main_hand_item).then_some("horizon.controller.guide.drop"),
+            ),
+            row(
+                "key.swapOffhand",
+                (player && any_item).then_some("horizon.controller.guide.swap"),
+            ),
+        ]
+        .into_iter()
+        .flatten()
+        .collect(),
+        right: [
+            row("key.attack", attack_caption(facts)),
+            row("key.use", use_caption(facts)),
+            row("key.pickItem", pick_caption(facts)),
+        ]
+        .into_iter()
+        .flatten()
+        .collect(),
+    }
+}
+
+fn jump_caption(f: &Facts) -> Option<&'static str> {
+    if f.riding {
+        f.vehicle_jumps.then_some("key.jump")
+    } else if f.flying {
+        Some("horizon.controller.guide.fly_up")
+    } else if f.gliding {
+        None
+    } else if f.in_water {
+        Some("horizon.controller.guide.swim_up")
+    } else if f.on_ground {
+        Some("key.jump")
+    } else if f.can_glide {
+        Some("horizon.controller.guide.glide")
+    } else {
+        f.may_fly.then_some("horizon.controller.guide.fly")
+    }
+}
+
+fn sneak_caption(f: &Facts) -> Option<&'static str> {
+    if f.riding {
+        Some("horizon.controller.guide.dismount")
+    } else if f.flying {
+        Some("horizon.controller.guide.fly_down")
+    } else if f.gliding {
+        None
+    } else if f.in_water && !f.on_ground {
+        Some("horizon.controller.guide.swim_down")
+    } else if f.sneak_latched {
+        Some("horizon.controller.guide.stand")
+    } else {
+        Some("key.sneak")
+    }
+}
+
+/// `Minecraft.handleKeybinds` spends attack clicks while an item is in use, and
+/// `startAttack` does nothing with busy hands.
+fn attack_caption(f: &Facts) -> Option<&'static str> {
+    if f.using.is_some() || f.hands_busy {
+        return None;
+    }
+    match f.target {
+        Target::Entity {
+            attackable: true, ..
+        } if f.spectator => Some("horizon.controller.guide.spectate"),
+        Target::Entity {
+            attackable: true, ..
+        } => Some("horizon.controller.guide.attack"),
+        Target::Block {
+            breakable: true, ..
+        } => Some("horizon.controller.guide.break"),
+        _ => None,
+    }
+}
+
+/// `Minecraft.startUseItem`: what is aimed at first, then the item.
+fn use_caption(f: &Facts) -> Option<&'static str> {
+    match f.using {
+        Some(Active::Shoot) => return Some("horizon.controller.guide.release_shoot"),
+        Some(Active::Throw) => return Some("horizon.controller.guide.release_throw"),
+        Some(Active::Stop) => return Some("horizon.controller.guide.release_stop"),
+        None => {}
+    }
+    if f.hands_busy {
+        return None;
+    }
+    let takes = match f.target {
+        Target::Block { takes, .. } | Target::Entity { takes, .. } => takes,
+        Target::None => None,
+    };
+    takes.or(f.item_use).map(Verb::caption)
+}
+
+fn pick_caption(f: &Facts) -> Option<&'static str> {
+    if f.spectator {
+        // key.spectatorHotbar is this button: it opens the teleport menu.
+        return Some("horizon.controller.guide.spectator_menu");
+    }
+    (f.can_pick && f.using.is_none()).then_some("key.pickItem")
+}
+
+/// What the crosshair is on in an inventory.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
+pub enum Under {
+    #[default]
+    Nothing,
+    /// A slot. `same` is the carried stack being its kind; `result` a crafting result, which is
+    /// only ever taken whole.
+    Slot {
+        item: bool,
+        same: bool,
+        result: bool,
+        /// The carried stack can go here.
+        accepts: bool,
+    },
+    Recipe {
+        direct_craft: bool,
+        alternatives: bool,
+    },
+    /// One of the recipe book's other controls.
+    Control,
+}
+
+/// What an inventory's rows are resolved from.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
+pub struct MenuFacts {
+    pub under: Under,
+    pub carrying: bool,
+    /// The recipe book is showing: the bumpers turn its pages, the triggers its categories.
+    pub book: bool,
+    /// The bumpers switch tabs.
+    pub tabs: bool,
+}
+
+/// An inventory's rows, by what they ask of the player: at the bottom right one face button, at the
+/// bottom left anything else (a trigger held with a button, the bumpers, View, a stick click). What
+/// the crosshair is on comes first in its column, the screen's own rows after, except Close, which
+/// stays lowest so the rest don't move it. Menu buttons aren't rebindable, so these name them.
+pub fn resolve_menu(f: &MenuFacts) -> Guide {
+    use Button::{East, LeftBumper, LeftStick, LeftTrigger, North, RightBumper, RightTrigger};
+    use Button::{Select, South, West};
+    const TAKE: &str = "horizon.controller.guide.take";
+    const MOVE: &str = "horizon.controller.guide.quick_move";
+    let under = match f.under {
+        // A result takes only into empty hands or the same stack.
+        Under::Slot {
+            item: true,
+            result: true,
+            same,
+            ..
+        } if !f.carrying || same => vec![Row::new(South, TAKE), Row::new(North, MOVE)],
+        Under::Slot { result: true, .. } => Vec::new(),
+        Under::Slot { accepts: false, .. } if f.carrying => Vec::new(),
+        Under::Slot { item, same, .. } if f.carrying => vec![
+            Row::new(
+                South,
+                if item && !same {
+                    "horizon.controller.guide.swap_stack"
+                } else {
+                    "horizon.controller.guide.put"
+                },
+            ),
+            Row::new(West, "horizon.controller.guide.put_one"),
+        ],
+        Under::Slot { item: true, .. } => vec![
+            Row::new(South, TAKE),
+            Row::new(West, "horizon.controller.guide.take_half"),
+            Row::new(North, MOVE),
+            Row::new(Select, "horizon.controller.guide.drop"),
+            Row::new(LeftStick, "horizon.controller.guide.drop_stack"),
+        ],
+        Under::Nothing | Under::Slot { .. } => Vec::new(),
+        Under::Recipe {
+            direct_craft,
+            alternatives,
+        } => [
+            Some(Row::new(South, "horizon.controller.guide.place_recipe")),
+            direct_craft.then_some(Row::pair(
+                LeftTrigger,
+                South,
+                "horizon.controller.direct_craft",
+            )),
+            Some(Row::new(North, "horizon.controller.guide.place_recipe_all")),
+            alternatives.then_some(Row::new(West, "horizon.controller.guide.alternatives")),
+        ]
+        .into_iter()
+        .flatten()
+        .collect(),
+        Under::Control => vec![Row::new(South, "horizon.controller.guide.select")],
+    };
+    let screen = [
+        f.book.then_some(Row::pair(
+            LeftBumper,
+            RightBumper,
+            "horizon.controller.guide.pages",
+        )),
+        f.book.then_some(Row::pair(
+            LeftTrigger,
+            RightTrigger,
+            "horizon.controller.guide.categories",
+        )),
+        (f.tabs && !f.book).then_some(Row::pair(
+            LeftBumper,
+            RightBumper,
+            "horizon.controller.guide.tabs",
+        )),
+    ];
+    let close = Row::new(East, "horizon.controller.guide.close");
+    let rows = std::iter::once(close)
+        .chain(under)
+        .chain(screen.into_iter().flatten());
+    let (right, left) =
+        rows.partition(|r| r.with.is_none() && matches!(r.button, South | East | West | North));
+    Guide { left, right }
+}
+
+/// A row's height and the view's margin, in GUI pixels.
+pub const ROW_HEIGHT: f32 = 11.0;
+const MARGIN: f32 = 2.0;
+
+fn overlap(a: &Rect, b: &Rect) -> bool {
+    a[0] < b[0] + b[2] && b[0] < a[0] + a[2] && a[1] < b[1] + b[3] && b[1] < a[1] + a[3]
+}
+
+/// Where a column's rows go, down from a top corner of the `[width, height]` view: under whatever
+/// a row would overlap in `taken`, or nowhere when that leaves the view's upper three quarters (the
+/// row is dropped: the rows come in the order they matter). The placed rows join `taken`.
+pub fn place_column(
+    view: [f32; 2],
+    left: bool,
+    widths: &[f32],
+    taken: &mut Vec<Rect>,
+) -> Vec<Option<Rect>> {
+    place(view, left, false, widths, taken)
+}
+
+/// `place_column`'s rows up from a bottom corner, over what they would overlap, within the view's
+/// lower quarter: the first row is the lowest.
+pub fn place_column_up(
+    view: [f32; 2],
+    left: bool,
+    widths: &[f32],
+    taken: &mut Vec<Rect>,
+) -> Vec<Option<Rect>> {
+    place(view, left, true, widths, taken)
+}
+
+fn place(
+    view: [f32; 2],
+    left: bool,
+    up: bool,
+    widths: &[f32],
+    taken: &mut Vec<Rect>,
+) -> Vec<Option<Rect>> {
+    let mut y = if up {
+        view[1] - MARGIN - ROW_HEIGHT
+    } else {
+        MARGIN
+    };
+    widths
+        .iter()
+        .map(|&width| {
+            if width > view[0] - 2.0 * MARGIN {
+                return None;
+            }
+            let x = if left {
+                MARGIN
+            } else {
+                view[0] - MARGIN - width
+            };
+            let mut at = y;
+            loop {
+                let outside = if up {
+                    at < view[1] * 0.75
+                } else {
+                    at + ROW_HEIGHT > view[1] * 0.75
+                };
+                if outside {
+                    return None;
+                }
+                let rect = [x, at, width, ROW_HEIGHT];
+                let hit = taken.iter().filter(|t| overlap(&rect, t));
+                let past = if up {
+                    hit.map(|t| t[1]).fold(f32::INFINITY, f32::min)
+                } else {
+                    hit.map(|t| t[1] + t[3]).fold(f32::NEG_INFINITY, f32::max)
+                };
+                if past.is_infinite() {
+                    taken.push(rect);
+                    y = if up {
+                        at - ROW_HEIGHT - 1.0
+                    } else {
+                        at + ROW_HEIGHT + 1.0
+                    };
+                    return Some(rect);
+                }
+                at = if up {
+                    past.floor() - ROW_HEIGHT - 1.0
+                } else {
+                    past.ceil() + 1.0
+                };
+            }
+        })
+        .collect()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn walking() -> Facts {
+        Facts {
+            on_ground: true,
+            can_sprint: true,
+            main_hand_item: true,
+            ..Facts::default()
+        }
+    }
+    fn on_block(f: Facts, breakable: bool, takes: Option<Verb>) -> Facts {
+        Facts {
+            target: Target::Block { breakable, takes },
+            ..f
+        }
+    }
+    fn rows(rows: &[Row]) -> Vec<(Button, &'static str)> {
+        rows.iter().map(|r| (r.button, r.caption)).collect()
+    }
+    fn captions(rows: &[Row]) -> Vec<&'static str> {
+        rows.iter().map(|r| r.caption).collect()
+    }
+
+    #[test]
+    fn survival_on_a_block_shows_break_use_and_pick_on_the_default_buttons() {
+        let facts = Facts {
+            can_pick: true,
+            item_use: Some(Verb::Place),
+            ..on_block(walking(), true, None)
+        };
+        let guide = resolve(&facts, &PadSettings::default());
+        assert_eq!(
+            rows(&guide.right),
+            [
+                (Button::RightTrigger, "horizon.controller.guide.break"),
+                (Button::LeftTrigger, "horizon.controller.guide.place"),
+                (Button::DPadLeft, "key.pickItem"),
+            ]
+        );
+        assert_eq!(
+            rows(&guide.left),
+            [
+                (Button::South, "key.jump"),
+                (Button::RightStick, "key.sneak"),
+                (Button::LeftStick, "key.sprint"),
+                (Button::North, "key.inventory"),
+                (Button::DPadDown, "horizon.controller.guide.drop"),
+                (Button::West, "horizon.controller.guide.swap"),
+            ]
+        );
+    }
+
+    #[test]
+    fn a_rebound_action_moves_its_row_and_an_unbound_one_loses_it() {
+        let mut settings = PadSettings::default();
+        settings.bind("key.attack", Some(Button::North));
+        settings.bind("key.pickItem", None);
+        settings.bind("key.jump", Some(Button::Start));
+        let facts = Facts {
+            can_pick: true,
+            ..on_block(walking(), true, None)
+        };
+        let guide = resolve(&facts, &settings);
+        assert_eq!(
+            rows(&guide.right),
+            [(Button::North, "horizon.controller.guide.break")]
+        );
+        // Start only ever pauses.
+        assert!(!captions(&guide.left).contains(&"key.jump"));
+    }
+
+    #[test]
+    fn what_a_block_or_entity_takes_comes_before_the_held_item() {
+        let settings = PadSettings::default();
+        let chest = Facts {
+            item_use: Some(Verb::Place),
+            ..on_block(walking(), true, Some(Verb::Open))
+        };
+        assert_eq!(
+            captions(&resolve(&chest, &settings).right),
+            [
+                "horizon.controller.guide.break",
+                "horizon.controller.guide.open"
+            ]
+        );
+        let villager = Facts {
+            item_use: Some(Verb::Eat),
+            target: Target::Entity {
+                attackable: true,
+                takes: Some(Verb::Trade),
+            },
+            ..walking()
+        };
+        assert_eq!(
+            captions(&resolve(&villager, &settings).right),
+            [
+                "horizon.controller.guide.attack",
+                "horizon.controller.guide.trade"
+            ]
+        );
+        // A mob the item means nothing to: the item is used on.
+        let cow = Facts {
+            target: Target::Entity {
+                attackable: true,
+                takes: None,
+            },
+            ..villager
+        };
+        assert_eq!(
+            captions(&resolve(&cow, &settings).right)[1],
+            "horizon.controller.guide.eat"
+        );
+    }
+
+    #[test]
+    fn nothing_to_do_leaves_the_right_column_empty() {
+        let settings = PadSettings::default();
+        assert!(resolve(&walking(), &settings).right.is_empty());
+        // An unbreakable block too (bedrock, a creative sword, adventure without can_break).
+        assert!(
+            resolve(&on_block(walking(), false, None), &settings)
+                .right
+                .is_empty()
+        );
+    }
+
+    #[test]
+    fn an_item_in_use_leaves_only_letting_go() {
+        let facts = Facts {
+            using: Some(Active::Shoot),
+            can_pick: true,
+            ..on_block(walking(), true, Some(Verb::Open))
+        };
+        assert_eq!(
+            captions(&resolve(&facts, &PadSettings::default()).right),
+            ["horizon.controller.guide.release_shoot"]
+        );
+    }
+
+    #[test]
+    fn busy_hands_neither_attack_nor_use() {
+        let facts = Facts {
+            hands_busy: true,
+            riding: true,
+            item_use: Some(Verb::Eat),
+            ..on_block(Facts::default(), true, None)
+        };
+        assert!(resolve(&facts, &PadSettings::default()).right.is_empty());
+    }
+
+    #[test]
+    fn movement_follows_what_the_player_is_doing() {
+        let settings = PadSettings::default();
+        let first_two = |f: Facts| {
+            let left = resolve(&f, &settings).left;
+            captions(&left).into_iter().take(2).collect::<Vec<_>>()
+        };
+        assert_eq!(
+            first_two(Facts {
+                flying: true,
+                may_fly: true,
+                ..Facts::default()
+            }),
+            [
+                "horizon.controller.guide.fly_up",
+                "horizon.controller.guide.fly_down"
+            ]
+        );
+        assert_eq!(
+            first_two(Facts {
+                in_water: true,
+                ..Facts::default()
+            }),
+            [
+                "horizon.controller.guide.swim_up",
+                "horizon.controller.guide.swim_down"
+            ]
+        );
+        // In the air, only a glider or creative flight makes a jump do anything.
+        assert_eq!(first_two(Facts::default()), ["key.sneak", "key.inventory"]);
+        assert_eq!(
+            first_two(Facts {
+                can_glide: true,
+                ..Facts::default()
+            })[0],
+            "horizon.controller.guide.glide"
+        );
+        assert_eq!(
+            first_two(Facts {
+                sneak_latched: true,
+                on_ground: true,
+                ..Facts::default()
+            })[1],
+            "horizon.controller.guide.stand"
+        );
+        // A boat can't jump; a saddled horse can; both dismount.
+        assert_eq!(
+            first_two(Facts {
+                riding: true,
+                on_ground: true,
+                ..Facts::default()
+            })[0],
+            "horizon.controller.guide.dismount"
+        );
+        assert_eq!(
+            first_two(Facts {
+                riding: true,
+                vehicle_jumps: true,
+                ..Facts::default()
+            }),
+            ["key.jump", "horizon.controller.guide.dismount"]
+        );
+        // Gliding: neither jump nor sneak does anything.
+        assert_eq!(
+            first_two(Facts {
+                gliding: true,
+                ..Facts::default()
+            }),
+            ["key.inventory"]
+        );
+    }
+
+    #[test]
+    fn a_spectator_only_flies_opens_spectates_and_has_its_menu() {
+        let facts = Facts {
+            spectator: true,
+            flying: true,
+            may_fly: true,
+            main_hand_item: true,
+            target: Target::Entity {
+                attackable: true,
+                takes: None,
+            },
+            ..Facts::default()
+        };
+        let guide = resolve(&facts, &PadSettings::default());
+        assert_eq!(
+            captions(&guide.right),
+            [
+                "horizon.controller.guide.spectate",
+                "horizon.controller.guide.spectator_menu"
+            ]
+        );
+        assert_eq!(
+            captions(&guide.left),
+            [
+                "horizon.controller.guide.fly_up",
+                "horizon.controller.guide.fly_down"
+            ]
+        );
+    }
+
+    #[test]
+    fn rows_stack_from_their_corner() {
+        let mut taken = Vec::new();
+        let left = place_column([200.0, 200.0], true, &[50.0, 30.0], &mut taken);
+        assert_eq!(left[0], Some([2.0, 2.0, 50.0, 11.0]));
+        assert_eq!(left[1], Some([2.0, 14.0, 30.0, 11.0]));
+        let right = place_column([200.0, 200.0], false, &[40.0], &mut taken);
+        assert_eq!(right[0], Some([158.0, 2.0, 40.0, 11.0]));
+    }
+
+    #[test]
+    fn a_row_goes_under_what_it_would_overlap() {
+        // The effect icons in the top right corner.
+        let mut taken = vec![[150.0, 1.0, 50.0, 24.0]];
+        let right = place_column([200.0, 200.0], false, &[40.0, 40.0], &mut taken);
+        assert_eq!(right[0], Some([158.0, 26.0, 40.0, 11.0]));
+        assert_eq!(right[1], Some([158.0, 38.0, 40.0, 11.0]));
+    }
+
+    #[test]
+    fn the_columns_of_a_narrow_view_never_overlap_and_late_rows_drop() {
+        // One quarter of a small window, a boss bar across its top: the rows have 31..67 left.
+        let view = [160.0, 90.0];
+        let bar = [0.0, 12.0, 160.0, 19.0];
+        let mut taken = vec![bar];
+        let right = place_column(view, false, &[90.0, 90.0, 90.0], &mut taken);
+        let left = place_column(view, true, &[90.0; 6], &mut taken);
+        let placed: Vec<Rect> = right.iter().chain(&left).flatten().copied().collect();
+        for (i, a) in placed.iter().enumerate() {
+            assert!(a[1] + a[3] <= 67.5 && a[0] >= 0.0 && a[0] + a[2] <= 160.0);
+            assert!(!overlap(a, &bar));
+            for b in &placed[i + 1..] {
+                assert!(!overlap(a, b), "{a:?} overlaps {b:?}");
+            }
+        }
+        // Three rows' worth of room, and the right column came first.
+        assert_eq!(right.iter().flatten().count(), 3);
+        assert_eq!(left.iter().flatten().count(), 0);
+    }
+
+    #[test]
+    fn rows_stack_up_from_a_bottom_corner_and_drop_above_its_quarter() {
+        let view = [200.0, 100.0];
+        let mut taken = vec![[0.0, 80.0, 60.0, 5.0]];
+        let left = place_column_up(view, true, &[50.0, 50.0], &mut taken);
+        assert_eq!(left[0], Some([2.0, 87.0, 50.0, 11.0]));
+        // Over the panel at 80 would be 68, under the lower quarter's 75.
+        assert_eq!(left[1], None);
+        let right = place_column_up(view, false, &[40.0], &mut taken);
+        assert_eq!(right[0], Some([158.0, 87.0, 40.0, 11.0]));
+    }
+
+    fn short(rows: &[Row]) -> Vec<&str> {
+        rows.iter()
+            .map(|r| r.caption.rsplit('.').next().unwrap_or(""))
+            .collect()
+    }
+
+    #[test]
+    fn an_inventorys_face_buttons_go_right_and_the_rest_left() {
+        let on = |under, carrying| {
+            resolve_menu(&MenuFacts {
+                under,
+                carrying,
+                ..MenuFacts::default()
+            })
+        };
+        let slot = |item, same, result| Under::Slot {
+            item,
+            same,
+            result,
+            accepts: true,
+        };
+        let close_only = ["close"];
+        let empty: [&str; 0] = [];
+        for quiet in [Under::Nothing, slot(false, false, false)] {
+            let guide = on(quiet, false);
+            assert_eq!(short(&guide.right), close_only);
+            assert_eq!(short(&guide.left), empty);
+        }
+        let item = on(slot(true, false, false), false);
+        assert_eq!(
+            short(&item.right),
+            ["close", "take", "take_half", "quick_move"]
+        );
+        assert_eq!(short(&item.left), ["drop", "drop_stack"]);
+        assert_eq!(
+            short(&on(slot(false, false, false), true).right),
+            ["close", "put", "put_one"]
+        );
+        assert_eq!(
+            short(&on(slot(true, false, false), true).right),
+            ["close", "swap_stack", "put_one"]
+        );
+        assert_eq!(
+            short(&on(slot(true, true, false), true).right),
+            ["close", "put", "put_one"]
+        );
+        assert_eq!(
+            short(&on(slot(true, false, true), false).right),
+            ["close", "take", "quick_move"]
+        );
+        let recipe = on(
+            Under::Recipe {
+                direct_craft: true,
+                alternatives: true,
+            },
+            false,
+        );
+        assert_eq!(
+            short(&recipe.right),
+            ["close", "place_recipe", "place_recipe_all", "alternatives"]
+        );
+        assert_eq!(recipe.left.len(), 1);
+        assert_eq!(recipe.left[0].with, Some(Button::LeftTrigger));
+        assert_eq!(recipe.left[0].button, Button::South);
+        let plain = on(
+            Under::Recipe {
+                direct_craft: false,
+                alternatives: false,
+            },
+            false,
+        );
+        assert_eq!(
+            short(&plain.right),
+            ["close", "place_recipe", "place_recipe_all"]
+        );
+        assert!(plain.left.is_empty());
+    }
+
+    #[test]
+    fn an_inventorys_screen_rows_follow_its_book_and_tabs() {
+        let left = |book, tabs| {
+            resolve_menu(&MenuFacts {
+                book,
+                tabs,
+                ..MenuFacts::default()
+            })
+            .left
+        };
+        assert!(left(false, false).is_empty());
+        assert_eq!(short(&left(true, false)), ["pages", "categories"]);
+        assert_eq!(short(&left(false, true)), ["tabs"]);
+    }
+
+    #[test]
+    fn a_row_wider_than_the_view_is_dropped() {
+        let mut taken = Vec::new();
+        assert_eq!(
+            place_column([50.0, 200.0], true, &[60.0, 20.0], &mut taken),
+            [None, Some([2.0, 2.0, 20.0, 11.0])]
+        );
+    }
+}
+
+#[cfg(test)]
+mod detail_tests {
+    use super::*;
+
+    fn rows() -> Guide {
+        Guide {
+            left: vec![Row::new(Button::South, "left")],
+            right: vec![Row::new(Button::East, "right")],
+        }
+    }
+
+    #[test]
+    fn full_keeps_both_columns() {
+        let guide = rows().at_detail(GuideDetail::Full);
+        assert_eq!((guide.left.len(), guide.right.len()), (1, 1));
+    }
+
+    #[test]
+    fn basic_keeps_the_right_column() {
+        let guide = rows().at_detail(GuideDetail::Basic);
+        assert_eq!((guide.left.len(), guide.right.len()), (0, 1));
+    }
+
+    #[test]
+    fn off_keeps_nothing() {
+        let guide = rows().at_detail(GuideDetail::Off);
+        assert_eq!((guide.left.len(), guide.right.len()), (0, 0));
+    }
+
+    #[test]
+    fn a_file_saved_with_the_old_switch_keeps_its_meaning() {
+        assert_eq!(GuideDetail::parse("true"), GuideDetail::Full);
+        assert_eq!(GuideDetail::parse("false"), GuideDetail::Off);
+        assert_eq!(GuideDetail::parse("basic"), GuideDetail::Basic);
+    }
+}
+
+#[cfg(test)]
+mod slot_tests {
+    use super::*;
+
+    /// The rows for the slot: South or West, whichever column they're in.
+    fn rows(item: bool, same: bool, result: bool, accepts: bool, carrying: bool) -> usize {
+        let guide = resolve_menu(&MenuFacts {
+            under: Under::Slot {
+                item,
+                same,
+                result,
+                accepts,
+            },
+            carrying,
+            ..MenuFacts::default()
+        });
+        [guide.left, guide.right]
+            .iter()
+            .flatten()
+            .filter(|row| matches!(row.button, Button::South | Button::West))
+            .count()
+    }
+
+    #[test]
+    fn a_slot_that_refuses_the_carried_stack_offers_nothing() {
+        assert_eq!(rows(false, false, false, false, true), 0);
+        assert_eq!(rows(true, true, false, false, true), 0);
+        assert!(rows(false, false, false, true, true) > 0);
+    }
+
+    #[test]
+    fn a_result_is_taken_only_into_empty_hands_or_the_same_stack() {
+        assert!(rows(true, false, true, true, false) > 0);
+        assert!(rows(true, true, true, true, true) > 0);
+        assert_eq!(rows(true, false, true, true, true), 0);
+    }
+}

crates/horizon-client-input/src/lib.rs

@@ -6,6 +6,7 @@
 pub mod actions;
 pub mod clipboard;
 pub mod gamepad;
+pub mod gameplay_guide;
 pub mod held;
 pub mod input;
 pub mod interaction_input;

crates/horizon-client-input/src/window.rs

@@ -393,38 +393,17 @@ impl FullscreenState {
         let reapply = self.set_exclusive(exclusive);
         self.set_preferred_mode(preferred);
         let mode_change = !in_video_screen && self.take_mode_change();
-        if wanted && window.is_maximized() {
-            window.set_maximized(false);
-            window.set_fullscreen(Some(fullscreen_request(
+        match request {
+            Some(false) => window.set_fullscreen(None),
+            Some(true) => enter_fullscreen(
                 window,
-                exclusive,
-                preferred.as_ref(),
-            )));
-        } else {
-            match request {
-                Some(false) => window.set_fullscreen(None),
-                Some(true) => {
-                    if window.is_maximized() {
-                        window.set_maximized(false);
-                    }
-                    window.set_fullscreen(Some(fullscreen_request(
-                        window,
-                        exclusive,
-                        preferred.as_ref(),
-                    )));
-                }
-                None if reapply || mode_change => {
-                    if window.is_maximized() {
-                        window.set_maximized(false);
-                    }
-                    window.set_fullscreen(Some(fullscreen_request(
-                        window,
-                        exclusive,
-                        preferred.as_ref(),
-                    )));
-                }
-                None => {}
-            }
+                fullscreen_request(window, exclusive, preferred.as_ref()),
+            ),
+            None if reapply || mode_change => enter_fullscreen(
+                window,
+                fullscreen_request(window, exclusive, preferred.as_ref()),
+            ),
+            None => {}
         }
     }
 
@@ -602,6 +581,34 @@ fn monitor_current_mode(
         .max_by_key(|m| (m.refresh_rate_millihertz(), m.bit_depth()))
 }
 
+/// `window.set_fullscreen(Some(fullscreen))`. On Windows a maximized window leaves its maximized
+/// state first: winit keeps a maximized window's client area inside the work area, so a
+/// borderless fullscreen kept the taskbar over its bottom and pushed its top off screen (#9984).
+pub fn enter_fullscreen(window: &winit::window::Window, fullscreen: winit::window::Fullscreen) {
+    #[cfg(target_os = "windows")]
+    if window.is_maximized() {
+        window.set_maximized(false);
+    }
+    window.set_fullscreen(Some(fullscreen));
+}
+
+/// Borderless fullscreen on the window's own monitor (the primary one when it has none).
+pub fn borderless_fullscreen(window: &winit::window::Window) -> winit::window::Fullscreen {
+    winit::window::Fullscreen::Borderless(
+        window
+            .current_monitor()
+            .or_else(|| window.primary_monitor()),
+    )
+}
+
+/// A window created fullscreen that the system also marked maximized enters it again
+/// unmaximized ([`enter_fullscreen`]); only Windows does that.
+pub fn settle_created_fullscreen(window: &winit::window::Window, fullscreen: bool) {
+    if cfg!(target_os = "windows") && fullscreen && window.is_maximized() {
+        enter_fullscreen(window, borderless_fullscreen(window));
+    }
+}
+
 /// `Window.applyFullscreen`: the fullscreen the window asks for. Exclusive fullscreen takes
 /// `Monitor.getPreferredVideoMode` (the preferred mode if the monitor has it, else the desktop
 /// mode); a monitor with no usable mode falls back to borderless, as vanilla does.

crates/horizon-client-lib/Cargo.toml

@@ -6,7 +6,7 @@ autotests = false
 version = "0.1.0"
 edition.workspace = true
 license.workspace = true
-rust-version = "1.90"
+rust-version.workspace = true
 description = "Reusable client systems, control tool and parity probes"
 
 [lib]
@@ -42,7 +42,8 @@ horizon-chat-filter = { path = "../horizon-chat-filter" }
 horizon-shaders = { path = "../horizon-shaders" }
 # Horizon's own shader packs: the format, the stages and the check (docs/shaders.md).
 horizon-shader-api = { path = "../horizon-shader-api" }
-horizon-friends = { path = "../horizon-friends" }
+# Play with Friends: invite codes and their tunnel; the `friends` feature.
+horizon-friends = { path = "../horizon-friends", optional = true }
 # The narrator (GameNarrator): text-to-speech of chat, system messages and screens.
 horizon-narrator = { path = "../horizon-narrator" }
 # Horizon mods: sandboxed WebAssembly components, off unless installed and turned on (docs/mods.md).
@@ -73,9 +74,10 @@ mio = { version = "1.2.4", features = ["os-poll", "net"] }
 xxhash-rust = { version = "0.8.19", features = ["xxh3"] }
 horizon-theme = { path = "../horizon-theme" }
 # Opt-in data collection: the game keeps, the launcher sends (docs/telemetry.md); `live` is
-# the anonymous "I'm playing" ping the game sends itself (`heartbeat.rs`).
-horizon-telemetry = { path = "../horizon-telemetry", default-features = false, features = ["live"] }
+# the anonymous "I'm playing" ping the game sends itself (`heartbeat.rs`), the `heartbeat` feature.
+horizon-telemetry = { path = "../horizon-telemetry", default-features = false }
 horizon-bench = { path = "../horizon-bench" }
+crc32fast = "1"
 zip = { version = "9.1.3", default-features = false, features = ["deflate"] }
 # Controllers (evdev + libudev on Linux, IOKit on macOS, Windows.Gaming.Input); the `controllers` feature.
 gilrs = { version = "0.11", optional = true }
@@ -112,12 +114,18 @@ objc2-foundation = { version = "0.3", default-features = false, features = ["std
 wgpu = { version = "30.0.1", default-features = false, features = ["gles"] }
 
 [features]
-default = ["audio", "controllers"]
+default = ["audio", "controllers", "discord", "friends", "heartbeat"]
 # Sound output. Without it (and `controllers`) the program links neither libasound nor libudev on
 # Linux: the server build (`--no-default-features`, released as horizon-engine; docs/server.md).
 audio = ["horizon-client-render/audio"]
 # Controllers: gilrs, and the DualSense's own output. Without it only `horizon-ctl pad`'s virtual pad.
 controllers = ["dep:gilrs", "dep:horizon-dualsense", "horizon-client-input/controllers"]
+# "Playing Horizon" on the player's Discord profile (`discord_presence`).
+discord = []
+# Play with Friends, joining side (`net.rs`): without it no invite code joins.
+friends = ["dep:horizon-friends"]
+# The anonymous "I'm playing" ping (`heartbeat.rs`, docs/telemetry.md).
+heartbeat = ["horizon-telemetry/live"]
 # Records the call sites of mob random draws (`mob_ai_probe` traces).
 rng-trace = ["horizon-core/rng-trace"]
 # Compatibility with earlier experiment commands: main already uses mimalloc.

crates/horizon-client-render/Cargo.toml

@@ -3,7 +3,7 @@ name = "horizon-client-render"
 version = "0.1.0"
 edition.workspace = true
 license.workspace = true
-rust-version = "1.90"
+rust-version.workspace = true
 description = "The client's world data, rendering and screens: chunks, meshing, light, streaming, the renderer, the HUD, menus and settings; no gameplay"
 
 [dependencies]
@@ -26,7 +26,7 @@ horizon-optifine = { path = "../horizon-optifine" }
 horizon-protocol = { path = "../horizon-protocol" }
 horizon-shader-api = { path = "../horizon-shader-api" }
 horizon-shaders = { path = "../horizon-shaders" }
-horizon-telemetry = { path = "../horizon-telemetry", default-features = false, features = ["live"] }
+horizon-telemetry = { path = "../horizon-telemetry", default-features = false }
 horizon-theme = { path = "../horizon-theme" }
 horizon-threads = { path = "../horizon-threads" }
 horizon-world = { path = "../horizon-world" }

crates/horizon-client-render/examples/brewing_fuel_probe.rs

@@ -0,0 +1,55 @@
+//! Headless production brewing-fuel component fixture.
+use horizon_client_render::{
+    brewing::{Brewing, BrewingStand, brewing_fuel},
+    providers::Providers,
+};
+use horizon_items::{
+    item_data::decode_components,
+    items::{ItemStack, Items},
+};
+use horizon_world::loot::PackOverlay;
+use std::{
+    io::{BufRead, Write},
+    path::Path,
+};
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let args: Vec<_> = std::env::args().collect();
+    let root = Path::new(&args[1]);
+    let items = Items::catalog(root, &PackOverlay::NONE)?;
+    let providers = Providers::load(root);
+    let brewing = Brewing {
+        recipes: vec![],
+        reagents: Default::default(),
+        inputs: Default::default(),
+    };
+    let mut out = std::io::BufWriter::new(std::fs::File::create(&args[3])?);
+    for line in std::io::BufReader::new(std::fs::File::open(&args[2])?).lines() {
+        let input: serde_json::Value = serde_json::from_str(&line?)?;
+        let mut stack = ItemStack::new(
+            input["item"].as_str().unwrap(),
+            input["count"].as_u64().unwrap() as u32,
+        );
+        let components = horizon_client_core::scoreboard::json_to_tag(&input["components"]);
+        let (_, extra) = decode_components(Some(&components));
+        stack.extra = extra;
+        let accepted = brewing_fuel(&items, &stack).is_some();
+        let mut stand = BrewingStand::new();
+        // A newly constructed vanilla block entity has no saved total yet.
+        stand.total_fuel = 0;
+        stand.items[4] = Some(stack);
+        for _ in 0..2 {
+            stand.tick(&brewing, &items, &providers);
+            writeln!(
+                out,
+                "{} {} {} {} {}",
+                accepted,
+                stand.fuel,
+                stand.total_fuel,
+                stand.speed.to_bits(),
+                stand.items[4].as_ref().map_or(0, |s| s.count)
+            )?;
+        }
+    }
+    Ok(())
+}

crates/horizon-client-render/examples/entity_shadow_ownership.rs

@@ -67,6 +67,7 @@ fn fixture(window: Arc<Window>) -> Result<(), Box<dyn std::error::Error>> {
         false,
         true,
         false,
+        false,
     ))?;
     assert!(!renderer.pack_entity_shadows(), "no selected pack");
     renderer.set_shader_pack(0, None, &[]).unwrap();

crates/horizon-client-render/examples/scene_replay.rs

@@ -225,6 +225,7 @@ fn replay(window: Arc<Window>) -> Result<(), Box<dyn std::error::Error>> {
         false,
         false,
         false,
+        false,
     ))?;
     drop(pixels);
     render.pixels.pack();

crates/horizon-client-render/examples/standard_pack_gpu_entities.rs

@@ -127,6 +127,7 @@ fn fixture(window: Arc<Window>) -> Result<(), Box<dyn std::error::Error>> {
         false,
         true,
         false,
+        false,
     ))?;
     renderer.resize(320, 180);
     assert!(
@@ -349,6 +350,7 @@ fn fixture_frame(hud: &HudBatch) -> Frame<'_> {
         skybox: false,
         end_sky: false,
         end_sky_sprite: None,
+        boss_world_fog: false,
         environment_fog: None,
         water_fog: [0.0; 3],
         fog: None,

crates/horizon-client-render/src/audio.rs

@@ -261,6 +261,40 @@ pub struct Audio {
     /// Ticks since the output devices were last looked at (`DeviceTracker.tick`).
     #[cfg(feature = "audio")]
     device_ticks: u32,
+    /// The look at the output devices running on its own thread, until a tick
+    /// takes its answer: listing them can take 100 ms (#11490).
+    #[cfg(feature = "audio")]
+    device_probe: Option<PendingProbe>,
+}
+/// What one look at the output devices found: the system default, the
+/// fingerprint, and the device list when those say it may have changed.
+#[cfg(feature = "audio")]
+struct DeviceProbe {
+    default: Option<String>,
+    cards: Option<String>,
+    devices: Option<Vec<String>>,
+}
+#[cfg(feature = "audio")]
+type PendingProbe = Arc<Mutex<Option<DeviceProbe>>>;
+/// Looks at the output devices as `should_change_device` did on the render
+/// thread: the device list only when the default or the fingerprint moved.
+#[cfg(feature = "audio")]
+fn probe_devices(default_seen: Option<String>, cards_seen: Option<String>) -> DeviceProbe {
+    let default = default_output_name();
+    let cards = card_fingerprint();
+    // Listing the devices probes every one (on Linux every built-in PCM,
+    // printing ALSA's errors for the plugins this system lacks; on macOS
+    // every Core Audio device, about 90 ms with twenty of them; on Windows
+    // every endpoint, with no fingerprint to skip it); only the fingerprint's
+    // devices can change the list, and it is cheap.
+    let devices = (default != default_seen
+        || cards_changed(cards_seen.as_deref(), cards.as_deref()))
+    .then(output_devices);
+    DeviceProbe {
+        default,
+        cards,
+        devices,
+    }
 }
 fn decode(path: &Path) -> Option<(Vec<f32>, u32, u16)> {
     use symphonia::core::{
@@ -1051,6 +1085,8 @@ impl Audio {
             devices_seen: devices,
             #[cfg(feature = "audio")]
             device_ticks: 0,
+            #[cfg(feature = "audio")]
+            device_probe: None,
         }
     }
     #[cfg(not(feature = "audio"))]
@@ -1211,6 +1247,8 @@ impl Audio {
             devices_seen: self.devices_seen.clone(),
             #[cfg(feature = "audio")]
             device_ticks: 0,
+            #[cfg(feature = "audio")]
+            device_probe: None,
         }
     }
     /// Sync the volume options, refreshing the categories that changed
@@ -1232,7 +1270,8 @@ impl Audio {
     /// `SoundEngine.shouldChangeDevice`: the open device was lost, the system
     /// default changed (with no device chosen in the options), or the chosen
     /// device came back; the output is then opened again. The devices are looked
-    /// at once a second.
+    /// at once a second, on a thread of their own: a later tick reads what it
+    /// found.
     #[cfg(feature = "audio")]
     fn should_change_device(&mut self) -> bool {
         // A splitscreen share plays through the first player's output: it leaves the device,
@@ -1246,29 +1285,54 @@ impl Audio {
         };
         if lost {
             log::info!("Horizon: audio device was lost");
+            self.device_probe = None;
             self.default_seen = default_output_name();
             self.cards_seen = card_fingerprint();
             self.devices_seen = output_devices();
             return true;
         }
+        if let Some(pending) = &self.device_probe {
+            let Some(probe) = pending.lock().ok().and_then(|mut found| found.take()) else {
+                return false;
+            };
+            self.device_probe = None;
+            return self.devices_changed(probe, current);
+        }
         self.device_ticks += 1;
         if self._stream.is_none() || self.device_ticks < 20 {
             return false;
         }
         self.device_ticks = 0;
-        let default = default_output_name();
-        let cards = card_fingerprint();
-        // Listing the devices probes every one (on Linux every built-in PCM,
-        // printing ALSA's errors for the plugins this system lacks; on macOS
-        // every Core Audio device, about 90 ms with twenty of them); only the
-        // fingerprint's devices can change the list, and it is cheap.
-        if default == self.default_seen
-            && !cards_changed(self.cards_seen.as_deref(), cards.as_deref())
-        {
-            return false;
+        let pending = PendingProbe::default();
+        let out = Arc::clone(&pending);
+        let seen = (self.default_seen.clone(), self.cards_seen.clone());
+        let started = std::thread::Builder::new()
+            .name("audio-devices".into())
+            .spawn(move || {
+                let probe = probe_devices(seen.0, seen.1);
+                if let Ok(mut found) = out.lock() {
+                    *found = Some(probe);
+                }
+            });
+        match started {
+            Ok(_) => self.device_probe = Some(pending),
+            Err(e) => log::warn!("Horizon: could not look at the audio devices: {e}"),
         }
+        false
+    }
+    /// The rest of `shouldChangeDevice` with what a look at the devices found,
+    /// `current` being the device playing now.
+    #[cfg(feature = "audio")]
+    fn devices_changed(&mut self, probe: DeviceProbe, current: String) -> bool {
+        let DeviceProbe {
+            default,
+            cards,
+            devices,
+        } = probe;
+        let Some(devices) = devices else {
+            return false;
+        };
         self.cards_seen = cards;
-        let devices = output_devices();
         // Only a change in the device lists is looked at, as in vanilla: a
         // preferred device that is listed but cannot open is not retried.
         if default == self.default_seen && devices == self.devices_seen {

crates/horizon-client-render/src/breaking.rs

@@ -114,12 +114,8 @@ mod tests {
             ambient_occlusion: true,
             particle: None,
             cube: None,
-            faces: vec![BakedFace {
-                layer: 0,
-                opaque: true,
-                translucent: false,
-                fusion: None,
-                quad: ModelQuad {
+            faces: vec![BakedFace::new(
+                ModelQuad {
                     positions: [
                         [0.0, 0.5, 0.0],
                         [0.0, 0.5, 1.0],
@@ -142,7 +138,11 @@ mod tests {
                     render_type: None,
                     shade: true,
                 },
-            }],
+                0,
+                true,
+                false,
+                None,
+            )],
         }
     }
     #[test]

crates/horizon-client-render/src/brewing.rs

@@ -387,8 +387,21 @@ impl BrewingStand {
         out.brewed = true;
     }
 }
-/// The `minecraft:brewing_fuel` providers of an item: (uses, speed_multiplier).
+/// `ItemStack.get(BREWING_FUEL)`: the stack's providers (uses, speed_multiplier),
+/// respecting component patches before falling back to the item's defaults.
 pub fn brewing_fuel(items: &Items, stack: &ItemStack) -> Option<(Value, Value)> {
+    if let Some(data) = stack.data() {
+        if data.other("!minecraft:brewing_fuel").is_some() {
+            return None;
+        }
+        if let Some(own) = data.other("minecraft:brewing_fuel") {
+            let component = horizon_client_core::scoreboard::tag_to_json(own);
+            return Some((
+                component["uses"].clone(),
+                component["speed_multiplier"].clone(),
+            ));
+        }
+    }
     items.get(&stack.item).and_then(|i| i.brewing_fuel.clone())
 }
 
@@ -396,6 +409,50 @@ pub fn brewing_fuel(items: &Items, stack: &ItemStack) -> Option<(Value, Value)>
 mod tests {
     use super::*;
 
+    #[test]
+    fn stack_fuel_controls_brew_duration_and_consumption() {
+        let items = Items::for_tests(Default::default());
+        let brewing = Brewing {
+            reagents: ["minecraft:nether_wart".to_owned()].into_iter().collect(),
+            inputs: HashSet::new(),
+            recipes: vec![BrewingRecipe {
+                id: "awkward".into(),
+                input: PotionIngredient {
+                    items: ["minecraft:potion".to_owned()].into_iter().collect(),
+                    potions: Some(["minecraft:water".to_owned()].into_iter().collect()),
+                },
+                reagent: PotionIngredient {
+                    items: ["minecraft:nether_wart".to_owned()].into_iter().collect(),
+                    potions: None,
+                },
+                output: ItemStack::new("minecraft:potion", 1).with_potion("minecraft:awkward"),
+            }],
+        };
+        let mut fuel = ItemStack::new("minecraft:stone", 2);
+        fuel.data_mut().set_loot_component(
+            "minecraft:brewing_fuel",
+            &serde_json::json!({"uses": 7, "speed_multiplier": 2.5}),
+        );
+        let mut stand = BrewingStand::new();
+        stand.items[0] = Some(ItemStack::new("minecraft:potion", 1).with_potion("minecraft:water"));
+        stand.items[3] = Some(ItemStack::new("minecraft:nether_wart", 1));
+        stand.items[4] = Some(fuel);
+        let providers = Providers::empty();
+        stand.tick(&brewing, &items, &providers);
+        assert_eq!((stand.brew_time, stand.fuel, stand.total_fuel), (160, 6, 7));
+        assert_eq!(stand.items[4].as_ref().unwrap().count, 1);
+        for _ in 1..160 {
+            assert!(!stand.tick(&brewing, &items, &providers).brewed);
+        }
+        assert!(stand.tick(&brewing, &items, &providers).brewed);
+        assert_eq!(
+            stand.items[0].as_ref().unwrap().potion(),
+            Some("minecraft:awkward")
+        );
+        assert_eq!(stand.fuel, 6);
+        assert_eq!(stand.items[4].as_ref().unwrap().count, 1);
+    }
+
     #[test]
     fn potion_colours_and_names() {
         // Swiftness: speed colour 3402751 = 0x33EBFF.

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

@@ -1188,6 +1188,18 @@ impl SuggestLayout {
     };
 }
 
+/// A suggestion accepted by Tab or a click (`SuggestionsList.useSuggestion`).
+#[derive(Debug, PartialEq, Eq)]
+pub struct SuggestionCompletion {
+    /// The suggestion list's original input, also when cycling with Tab.
+    pub original: String,
+    /// The replaced range in `original`, as Java UTF-16 start/end offsets.
+    pub range: (usize, usize),
+    pub text: String,
+    /// The resulting input, after the text field's length limit.
+    pub input: String,
+}
+
 /// The open chat screen: vanilla's `ChatScreen` with its `EditBox` and
 /// `CommandSuggestions` (argument colouring, usage lines, parse errors,
 /// the suggestion list, Tab completion, history).
@@ -1211,6 +1223,7 @@ pub struct ChatScreen {
     /// the command up to the cursor.
     request: Option<(i32, String)>,
     suggestions: Option<SuggestionList>,
+    completion: Option<SuggestionCompletion>,
     usage: Vec<Text>,
     usage_position: i32,
     usage_width: i32,
@@ -1333,6 +1346,7 @@ impl ChatScreen {
             awaiting: None,
             request: None,
             suggestions: None,
+            completion: None,
             usage: Vec::new(),
             usage_position: 0,
             usage_width: 0,
@@ -1370,6 +1384,7 @@ impl ChatScreen {
             awaiting: None,
             request: None,
             suggestions: None,
+            completion: None,
             usage: Vec::new(),
             usage_position: 0,
             usage_width: 0,
@@ -1385,6 +1400,11 @@ impl ChatScreen {
     pub fn value(&self) -> &str {
         &self.input.value
     }
+    /// Take the most recently accepted suggestion, at most once. Call after
+    /// each key or click to observe every acceptance, including Tab cycling.
+    pub fn take_suggestion_completion(&mut self) -> Option<SuggestionCompletion> {
+        self.completion.take()
+    }
     /// Replace the input for a suggest-command link and refresh completions.
     pub fn suggest_command(&mut self, m: &Measure, c: &Commands, command: &str) {
         self.input.set_value(m, command);
@@ -1434,6 +1454,24 @@ impl ChatScreen {
             self.edited(m, c);
         }
     }
+    /// Edit the existing input and refresh its command responder when it changes.
+    pub fn edit_input(&mut self, m: &Measure, c: &Commands, f: impl FnOnce(&mut TextField)) {
+        let before = (
+            self.input.value.clone(),
+            self.input.cursor,
+            self.input.highlight,
+        );
+        f(&mut self.input);
+        if before
+            != (
+                self.input.value.clone(),
+                self.input.cursor,
+                self.input.highlight,
+            )
+        {
+            self.edited(m, c);
+        }
+    }
     /// Typed text (`charTyped` per character).
     pub fn type_text(&mut self, m: &Measure, c: &Commands, text: &str) {
         for ch in text.chars() {
@@ -1733,6 +1771,17 @@ impl ChatScreen {
         self.select(l, l.current as isize);
         self.keep_suggestions = false;
         l.tab_cycles = true;
+        let units = |byte: usize| {
+            l.original[..byte.min(l.original.len())]
+                .encode_utf16()
+                .count()
+        };
+        self.completion = Some(SuggestionCompletion {
+            original: l.original.clone(),
+            range: (units(s.range.0), units(s.range.1)),
+            text: s.text,
+            input: self.input.value.clone(),
+        });
     }
     /// `ChatScreen.keyPressed`.
     pub fn key(
@@ -2022,6 +2071,11 @@ impl ChatScreen {
         for i in 0..limit {
             let y = ry + 12 * i as i32;
             d::fill(out, rx, y, rx + rw, y + 12, self.layout.fill);
+            // A row for the pad: nothing else can pick a suggestion without Tab.
+            crate::widgets::target_as(
+                [rx as f32, y as f32, rw as f32, 12.0],
+                crate::widgets::Kind::Row,
+            );
             if mouse.0 > rx && mouse.0 < rx + rw && mouse.1 > y && mouse.1 < y + 12 {
                 if moved {
                     self.select(l, (i + l.offset) as isize);

crates/horizon-client-render/src/chat_tests.rs

@@ -7,6 +7,85 @@ fn full() -> ChatAbilities {
     ChatAbilities::new(ChatVisibility::Full)
 }
 
+#[test]
+fn accepted_suggestions_report_utf16_ranges_and_tab_cycles() {
+    use winit::keyboard::KeyCode as K;
+    let font = font();
+    let m = Measure(&font);
+    let registries = Registries {
+        players: vec!["Steve".into(), "Steven".into()],
+        ..Registries::default()
+    };
+    let c = Commands {
+        dispatcher: crate::command::vanilla::game_dispatcher(),
+        registries: &registries,
+    };
+    let mut screen = ChatScreen::new(&m, &c, "", false, 0, 640, 360, full());
+    screen.type_text(&m, &c, "😀 hi st");
+    assert!(screen.take_suggestion_completion().is_none());
+    screen.key(&m, &c, &[], K::Tab, false, false);
+    assert!(
+        screen.take_suggestion_completion().is_none(),
+        "opening is not accepting"
+    );
+    for (shift, text) in [(false, "Steve"), (false, "Steven"), (true, "Steve")] {
+        screen.key(&m, &c, &[], K::Tab, shift, false);
+        assert_eq!(screen.value(), format!("😀 hi {text}"));
+        assert_eq!(
+            screen.take_suggestion_completion(),
+            Some(SuggestionCompletion {
+                original: "😀 hi st".into(),
+                range: (6, 8),
+                text: text.into(),
+                input: format!("😀 hi {text}"),
+            })
+        );
+        assert!(
+            screen.take_suggestion_completion().is_none(),
+            "reported once"
+        );
+    }
+    screen.key(&m, &c, &[], K::ArrowDown, false, false);
+    assert!(
+        screen.take_suggestion_completion().is_none(),
+        "selection is not accepting"
+    );
+    screen.key(&m, &c, &[], K::Escape, false, false);
+    assert!(screen.take_suggestion_completion().is_none());
+}
+
+#[test]
+fn clicked_suggestion_reports_the_actual_length_limited_input() {
+    use winit::keyboard::KeyCode as K;
+    let font = font();
+    let m = Measure(&font);
+    let registries = Registries {
+        players: vec!["Steve".into()],
+        ..Registries::default()
+    };
+    let c = Commands {
+        dispatcher: crate::command::vanilla::game_dispatcher(),
+        registries: &registries,
+    };
+    let mut screen = ChatScreen::new(&m, &c, "", false, 0, 640, 360, full());
+    screen.input.max_length = 6;
+    screen.type_text(&m, &c, "hi st");
+    screen.key(&m, &c, &[], K::Tab, false, false);
+    let [x, y, _, _] = screen.suggestions.as_ref().unwrap().rect;
+    assert!(screen.click(&m, &c, f64::from(x + 1), f64::from(y + 1)));
+    assert_eq!(screen.value(), "hi Ste");
+    assert_eq!(
+        screen.take_suggestion_completion(),
+        Some(SuggestionCompletion {
+            original: "hi st".into(),
+            range: (3, 5),
+            text: "Steve".into(),
+            input: "hi Ste".into(),
+        })
+    );
+    assert!(screen.take_suggestion_completion().is_none());
+}
+
 fn font() -> Font {
     // The missing-glyph metrics let these tests run without game assets.
     Font::load(
@@ -483,8 +562,18 @@ fn ask_server_nodes_wait_for_the_servers_completions() {
     tab(&mut screen);
     assert_eq!(screen.value(), "/bossbar get pt");
     screen.server_suggestions(&m, &c, request, (13, 2), reply("pt6:check"));
+    assert!(screen.take_suggestion_completion().is_none());
     tab(&mut screen);
     assert_eq!(screen.value(), "/bossbar get pt6:check");
+    assert_eq!(
+        screen.take_suggestion_completion(),
+        Some(SuggestionCompletion {
+            original: "/bossbar get pt".into(),
+            range: (13, 15),
+            text: "pt6:check".into(),
+            input: "/bossbar get pt6:check".into(),
+        })
+    );
     // Without the server's provider the local list is done at once.
     let local = crate::command::vanilla::game_dispatcher();
     let c = Commands {

crates/horizon-client-render/src/chunk/block_entity.rs

@@ -11,7 +11,7 @@ use horizon_world::{
 use std::{
     collections::HashMap,
     sync::{
-        Arc,
+        Arc, Mutex, OnceLock, PoisonError,
         atomic::{AtomicU64, Ordering},
     },
 };
@@ -108,6 +108,9 @@ pub enum BlockEntity {
 pub struct ModBlockEntity {
     fields: ModBlockEntityFields,
     revision: ModRevision,
+    // A client update can consume transient effects without changing saved
+    // fields. Most entities never use this; do not allocate their queue.
+    client_update_fields: OnceLock<Mutex<Compound>>,
 }
 /// What a `ModBlockEntity` holds: its type id (`mymod:machine`), its saved
 /// compound without `id`, `x`, `y`, `z` and `Items`, its item slots
@@ -138,11 +141,55 @@ impl ModBlockEntity {
                 born: MOD_BLOCK_ENTITIES_MADE.fetch_add(1, Ordering::Relaxed),
                 changes: 0,
             },
+            client_update_fields: OnceLock::new(),
         }
     }
     pub fn revision(&self) -> ModRevision {
         self.revision
     }
+    /// Replace the owner's pending, one-shot client update fields. These
+    /// fields are not saved, cloned, compared or retained for drawing, and
+    /// changing them does not change this entity's revision. The owner must
+    /// explicitly take and merge them into its update tag. Calling this does
+    /// not schedule a block update.
+    ///
+    /// An empty batch clears a pending batch without allocating an idle queue.
+    pub fn set_client_update_fields(&mut self, fields: Compound) {
+        if fields.is_empty() {
+            self.clear_client_update_fields();
+            return;
+        }
+        *self
+            .client_update_fields
+            .get_or_init(|| Mutex::new(Compound::new()))
+            .lock()
+            .unwrap_or_else(PoisonError::into_inner) = fields;
+    }
+    /// Discard the owner's pending client update fields, without changing
+    /// saved data, revision or a queue that has never been used.
+    pub fn clear_client_update_fields(&mut self) {
+        if let Some(fields) = self.client_update_fields.get() {
+            fields
+                .lock()
+                .unwrap_or_else(PoisonError::into_inner)
+                .clear();
+        }
+    }
+    /// Atomically take the owner's pending fields at update-tag construction.
+    /// A loaded chunk and a block change use this same boundary. Construct a
+    /// tag once, then send that tag to every recipient; another construction
+    /// sees an empty batch. A save or a clone does not consume this batch.
+    ///
+    /// This is safe for an update-tag hook receiving only a shared reference,
+    /// including a saved chunk encoded by a worker thread. If a previous lock
+    /// holder panicked, preserve its pending data instead of dropping it.
+    pub fn take_client_update_fields(&self) -> Compound {
+        self.client_update_fields
+            .get()
+            .map_or_else(Compound::new, |fields| {
+                std::mem::take(&mut *fields.lock().unwrap_or_else(PoisonError::into_inner))
+            })
+    }
     /// A client's copy loads the tag the server sent (`loadWithComponents`
     /// in `ClientPacketListener.handleBlockEntityData`): `tag`'s fields
     /// replace its own of the same names. One it already has as sent is
@@ -706,6 +753,85 @@ pub struct CommandBlock {
 mod tests {
     use super::*;
 
+    #[test]
+    fn transient_client_update_fields_are_lazy_replaceable_and_drained_once() {
+        let mut machine = ModBlockEntity::new(ModBlockEntityFields {
+            id: "test:machine".into(),
+            nbt: Compound::from([("progress".into(), Tag::Int(7))]),
+            ..Default::default()
+        });
+        let revision = machine.revision();
+        let saved = machine.fields.clone();
+        let debug = format!("{machine:?}");
+        machine.clear_client_update_fields();
+        machine.set_client_update_fields(Compound::new());
+        assert!(machine.take_client_update_fields().is_empty());
+        assert!(machine.client_update_fields.get().is_none());
+
+        machine.set_client_update_fields(Compound::from([("discarded".into(), Tag::Int(1))]));
+        let expected = Compound::from([("effects".into(), Tag::List(vec![Tag::Int(2)]))]);
+        machine.set_client_update_fields(expected.clone());
+        assert_eq!(machine.take_client_update_fields(), expected);
+        assert!(machine.take_client_update_fields().is_empty());
+
+        machine.set_client_update_fields(expected.clone());
+        let copy = machine.clone();
+        assert_eq!(machine, copy, "transient fields are not retained contents");
+        assert_ne!(machine.revision(), copy.revision());
+        assert!(copy.client_update_fields.get().is_none());
+        assert!(copy.take_client_update_fields().is_empty());
+        assert_eq!(machine.take_client_update_fields(), expected);
+        machine.set_client_update_fields(expected);
+        machine.clear_client_update_fields();
+        assert!(machine.take_client_update_fields().is_empty());
+        assert_eq!(machine.fields, saved);
+        assert_eq!(machine.revision(), revision);
+        assert_eq!(format!("{machine:?}"), debug);
+    }
+
+    #[test]
+    fn concurrent_client_update_constructions_consume_one_batch() {
+        let mut machine = ModBlockEntity::default();
+        let expected = Compound::from([("effects".into(), Tag::Int(23))]);
+        machine.set_client_update_fields(expected.clone());
+        let received = std::thread::scope(|scope| {
+            let handles = (0..16)
+                .map(|_| scope.spawn(|| machine.take_client_update_fields()))
+                .collect::<Vec<_>>();
+            handles
+                .into_iter()
+                .map(|h| h.join().unwrap())
+                .collect::<Vec<_>>()
+        });
+        let nonempty = received
+            .into_iter()
+            .filter(|c| !c.is_empty())
+            .collect::<Vec<_>>();
+        assert_eq!(nonempty, [expected]);
+    }
+
+    #[test]
+    fn a_poisoned_client_update_lock_preserves_its_pending_batch() {
+        let mut machine = ModBlockEntity::default();
+        let expected = Compound::from([("effects".into(), Tag::Int(23))]);
+        machine.set_client_update_fields(expected.clone());
+        std::thread::scope(|scope| {
+            assert!(
+                scope
+                    .spawn(|| {
+                        let _held = machine.client_update_fields.get().unwrap().lock().unwrap();
+                        panic!("interrupt before consuming the queued batch");
+                    })
+                    .join()
+                    .is_err()
+            );
+        });
+        assert_eq!(machine.take_client_update_fields(), expected);
+        assert!(machine.take_client_update_fields().is_empty());
+        machine.set_client_update_fields(expected.clone());
+        assert_eq!(machine.take_client_update_fields(), expected);
+    }
+
     #[test]
     fn a_mod_block_entitys_revision_moves_with_each_change_and_only_then() {
         let mut machine = ModBlockEntity::new(ModBlockEntityFields {

crates/horizon-client-render/src/controller_ui.rs

@@ -65,6 +65,44 @@ pub struct Setting {
     pub item: Item,
     pub text: &'static str,
 }
+/// What the chosen value does, for a setting whose values each do something different.
+fn choice_description(opt: Opt, pad: &PadSettings) -> Option<&'static str> {
+    Some(match opt {
+        Opt::PadGameplayGuide => match pad.guide_detail {
+            gamepad::GuideDetail::Full => {
+                "Shows what your buttons do right now, in play and in inventories."
+            }
+            gamepad::GuideDetail::Basic => {
+                "Shows only what you can do with what you're looking at, and the main inventory buttons."
+            }
+            gamepad::GuideDetail::Off => "Doesn't show what your buttons do.",
+        },
+        Opt::PadGlyphs => match pad.glyphs {
+            GlyphStyle::Auto => "Shows the buttons of the controller you're using.",
+            GlyphStyle::Xbox => "Always shows Xbox buttons.",
+            GlyphStyle::PlayStation => "Always shows PlayStation buttons.",
+            GlyphStyle::Nintendo => "Always shows Nintendo buttons.",
+        },
+        Opt::PadKeyboard => match pad.keyboard {
+            gamepad::TextKeyboard::Auto => {
+                "Opens Steam's keyboard on a Steam Deck under Steam, and Horizon's otherwise."
+            }
+            gamepad::TextKeyboard::Horizon => "Always opens Horizon's keyboard.",
+            gamepad::TextKeyboard::Steam => "Always opens Steam's keyboard.",
+        },
+        Opt::PadLightbar => match pad.lightbar {
+            gamepad::Lightbar::Health => {
+                "A DualSense's light shows your health, from green through amber to red."
+            }
+            gamepad::Lightbar::Dimension => {
+                "A DualSense's light changes with the dimension you're in."
+            }
+            gamepad::Lightbar::Off => "A DualSense keeps its own light.",
+        },
+        _ => return None,
+    })
+}
+
 fn option(opt: Opt, text: &'static str) -> Setting {
     Setting {
         item: Item::Option(opt),
@@ -97,10 +135,16 @@ pub fn rows() -> Vec<(Page, Vec<(&'static str, Vec<Setting>)>)> {
             vec![
                 (
                     "Controller",
-                    vec![option(
-                        Opt::PadEnabled,
-                        "Off, the game ignores every controller for this player.",
-                    )],
+                    vec![
+                        option(
+                            Opt::PadEnabled,
+                            "Off, the game ignores every controller for this player.",
+                        ),
+                        option(
+                            Opt::PadPlayInBackground,
+                            "The controller keeps playing while this window isn't focused, and losing focus won't pause.",
+                        ),
+                    ],
                 ),
                 (
                     "Look",
@@ -135,10 +179,16 @@ pub fn rows() -> Vec<(Page, Vec<(&'static str, Vec<Setting>)>)> {
                 ),
                 (
                     "Play",
-                    vec![option(
-                        Opt::PadTriggerThreshold,
-                        "How far a trigger is pulled before it counts as pressed.",
-                    )],
+                    vec![
+                        option(
+                            Opt::PadGameplayGuide,
+                            "Show the buttons for what you can do, while you play with a controller.",
+                        ),
+                        option(
+                            Opt::PadTriggerThreshold,
+                            "How far a trigger is pulled before it counts as pressed.",
+                        ),
+                    ],
                 ),
                 (
                     "Menus",
@@ -279,6 +329,7 @@ impl Item {
         match self {
             Item::Option(Opt::PadEnabled) => Some(c.enabled),
             Item::Option(Opt::PadVibration) => Some(c.vibration),
+            Item::Option(Opt::PadPlayInBackground) => Some(c.play_in_background),
             Item::Option(Opt::PadAdaptiveTriggers) => Some(c.adaptive_triggers),
             Item::Option(Opt::PadInvertX) => Some(c.invert_x),
             Item::Option(Opt::PadInvertY) => Some(c.invert_y),
@@ -604,6 +655,7 @@ impl ControllerUi {
                             hover,
                             focused,
                             held: self.dragging == Some(item),
+                            key: None,
                         };
                         shell::row(batch, atlas, &cols, y, &view);
                     }
@@ -818,8 +870,12 @@ impl ControllerUi {
     /// What a row does. A binding names the controller's own buttons, and what else its button
     /// does when it shares it.
     fn description(&self, setting: Setting, s: &Settings) -> String {
-        let Item::Bind(action) = setting.item else {
-            return lang::get(setting.text);
+        let action = match setting.item {
+            Item::Bind(action) => action,
+            Item::Option(opt) => {
+                return lang::get(choice_description(opt, &s.controller).unwrap_or(setting.text));
+            }
+            _ => return lang::get(setting.text),
         };
         let pad = &s.controller;
         let style = self.context.style;
@@ -1265,6 +1321,7 @@ mod tests {
         for opt in [
             Opt::PadEnabled,
             Opt::PadVibration,
+            Opt::PadPlayInBackground,
             Opt::PadAdaptiveTriggers,
             Opt::PadLightbar,
             Opt::PadLookSensitivity,
@@ -1372,6 +1429,30 @@ mod tests {
         assert!((s.controller.move_deadzone - before - 0.01).abs() < 0.001);
     }
 
+    /// What the screen draws at the bottom of the page changes with the choice, in every one of
+    /// these settings.
+    #[test]
+    fn each_choice_describes_itself() {
+        let ui = ControllerUi::default();
+        let mut s = Settings::default();
+        for (opt, choices) in [
+            (Opt::PadGameplayGuide, 3),
+            (Opt::PadGlyphs, 4),
+            (Opt::PadKeyboard, 3),
+            (Opt::PadLightbar, 3),
+        ] {
+            let setting = option(opt, "the fixed sentence");
+            let mut seen = Vec::new();
+            for _ in 0..choices {
+                let text = ui.description(setting, &s);
+                assert_ne!(text, "the fixed sentence", "{opt:?}");
+                assert!(!seen.contains(&text), "{opt:?} repeats {text}");
+                seen.push(text);
+                opt.cycle(&mut s, false, FB);
+            }
+        }
+    }
+
     #[test]
     fn every_text_is_in_the_language_table() {
         let (_, missed) = lang::scoped(lang::Language::load(&[], "de_de"), || {
@@ -1385,6 +1466,18 @@ mod tests {
                     }
                 }
             }
+            let mut settings = Settings::default();
+            for opt in [
+                Opt::PadGameplayGuide,
+                Opt::PadGlyphs,
+                Opt::PadKeyboard,
+                Opt::PadLightbar,
+            ] {
+                for _ in 0..4 {
+                    lang::get(choice_description(opt, &settings.controller).unwrap());
+                    opt.cycle(&mut settings, false, FB);
+                }
+            }
             for text in [
                 "Controller",
                 "Player profile",

crates/horizon-client-render/src/custom_sky.rs

@@ -0,0 +1,243 @@
+//! OptiFine custom skies (`horizon_optifine::sky`) as the game draws them: a pack's layers with
+//! their decoded textures, read once with the pack, and each frame's choice of layers, their
+//! brightness and rotation ([`CustomSky::draws`]), which `gfx::custom_sky` draws over the
+//! vanilla sky. A pack without `optifine/sky` gives an empty [`CustomSky`] and the sky stays
+//! vanilla.
+
+use std::path::Path;
+
+use glam::{Mat4, Vec3};
+use horizon_optifine::sky::{Blend, Conditions, Skies, SkyLayer, Transition};
+
+/// A layer's texture, RGBA8.
+pub struct Image {
+    pub width: u32,
+    pub height: u32,
+    pub rgba: Vec<u8>,
+}
+
+/// The pack's layers, by world, with one texture per layer (`images[i]` for the `i`th layer
+/// over all worlds, in `worlds` order).
+#[derive(Default)]
+pub struct CustomSky {
+    worlds: Vec<(i32, Vec<SkyLayer>)>,
+    pub images: Vec<Image>,
+}
+
+/// One layer of a frame: which texture, with which blend, how bright and turned how.
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub struct Draw {
+    pub image: u16,
+    pub blend: Blend,
+    pub brightness: f32,
+    /// Camera-relative world from the skybox's space.
+    pub rotation: Mat4,
+}
+
+/// The eased brightness of each layer, kept by the game between frames.
+#[derive(Default)]
+pub struct State {
+    world: Option<i32>,
+    eased: Vec<Transition>,
+}
+
+/// Textures past this many texels in all are left out (a skybox is a few megapixels at most).
+const TEXEL_BUDGET: u64 = 64 << 20;
+
+impl CustomSky {
+    /// The custom skies of the overlay at `root`. A layer whose texture does not decode is
+    /// dropped with a warning.
+    pub fn load(root: &Path) -> Self {
+        let skies = Skies::scan(root);
+        let mut out = Self::default();
+        let mut texels = 0u64;
+        for (world, sky) in skies.worlds {
+            let mut layers = Vec::new();
+            for layer in sky.layers {
+                match crate::hud::decode(&root.join(&layer.source)) {
+                    Ok((width, height, rgba))
+                        if texels + u64::from(width) * u64::from(height) <= TEXEL_BUDGET =>
+                    {
+                        texels += u64::from(width) * u64::from(height);
+                        out.images.push(Image {
+                            width,
+                            height,
+                            rgba,
+                        });
+                        layers.push(layer);
+                    }
+                    Ok(_) => log::warn!("{}: past the custom sky's texture budget", layer.source),
+                    Err(e) => log::warn!("{}: {e:#}", layer.source),
+                }
+            }
+            if !layers.is_empty() {
+                out.worlds.push((world, layers));
+            }
+        }
+        out
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.worlds.is_empty()
+    }
+
+    /// Whether `world` has layers (`0` the Overworld, `1` the End).
+    pub fn has(&self, world: i32) -> bool {
+        self.worlds.iter().any(|(w, _)| *w == world)
+    }
+
+    /// This frame's layers of `world` into `out` (cleared first), in drawing order: those whose
+    /// conditions hold, eased over their `transition` by `seconds` since the last frame, at the
+    /// brightness of their fade times. `sun_turns` is the sun's angle over 360° (`0` at noon).
+    pub fn draws(
+        &self,
+        world: i32,
+        conditions: &Conditions,
+        sun_turns: f32,
+        seconds: f32,
+        state: &mut State,
+        out: &mut Vec<Draw>,
+    ) {
+        out.clear();
+        let mut first = 0;
+        let mut found = None;
+        for (w, layers) in &self.worlds {
+            if *w == world {
+                found = Some(layers);
+                break;
+            }
+            first += layers.len();
+        }
+        let Some(layers) = found else {
+            state.world = None;
+            return;
+        };
+        // A new world (or pack) starts each layer where its conditions put it: no fade in.
+        let snap = state.world != Some(world) || state.eased.len() != layers.len();
+        if snap {
+            state.world = Some(world);
+            state.eased.clear();
+            state.eased.resize(layers.len(), Transition::default());
+        }
+        for (i, (layer, eased)) in layers.iter().zip(&mut state.eased).enumerate() {
+            let target = if layer.shows(conditions) { 1.0 } else { 0.0 };
+            let shown = if snap {
+                eased.value = target;
+                target
+            } else {
+                eased.step(target, seconds, layer.transition)
+            };
+            let brightness = shown * layer.brightness(conditions.day_time);
+            if brightness <= 0.0 {
+                continue;
+            }
+            let turns = layer.turns(conditions.day_time, sun_turns);
+            let rotation = if turns == 0.0 {
+                Mat4::IDENTITY
+            } else {
+                Mat4::from_axis_angle(Vec3::from_array(layer.axis), turns * std::f32::consts::TAU)
+            };
+            out.push(Draw {
+                image: (first + i) as u16,
+                blend: layer.blend,
+                brightness,
+                rotation,
+            });
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use horizon_optifine::sky::Now;
+
+    fn pack(files: &[(&str, &str)]) -> (std::path::PathBuf, CustomSky) {
+        let root = std::env::temp_dir().join(format!(
+            "horizon-custom-sky-{}-{}",
+            std::process::id(),
+            files.len()
+        ));
+        let _ = std::fs::remove_dir_all(&root);
+        let dir = root.join("assets/minecraft/optifine/sky/world0");
+        std::fs::create_dir_all(&dir).unwrap();
+        let png = {
+            let mut bytes = Vec::new();
+            let mut encoder = png::Encoder::new(&mut bytes, 6, 4);
+            encoder.set_color(png::ColorType::Rgba);
+            encoder.set_depth(png::BitDepth::Eight);
+            let mut writer = encoder.write_header().unwrap();
+            writer
+                .write_image_data(&[255, 0, 0, 255].repeat(24))
+                .unwrap();
+            writer.finish().unwrap();
+            bytes
+        };
+        for (name, text) in files {
+            std::fs::write(dir.join(format!("{name}.properties")), text).unwrap();
+            std::fs::write(dir.join(format!("{name}.png")), &png).unwrap();
+        }
+        let sky = CustomSky::load(&root);
+        (root, sky)
+    }
+
+    fn noon(biome: &str) -> Conditions<'_> {
+        Conditions {
+            day_time: 6000,
+            weather: Now::Clear,
+            biome,
+            y: 64,
+        }
+    }
+
+    #[test]
+    fn layers_ease_in_at_a_biome_border_but_not_on_arrival() {
+        let (root, sky) = pack(&[
+            ("sky1", "biomes=desert\ntransition=2"),
+            ("sky2", "blend=alpha\nrotate=false"),
+        ]);
+        let _ = std::fs::remove_dir_all(root);
+        assert!(sky.has(0) && !sky.has(1));
+        assert_eq!(sky.images[0].width, 6);
+        let (mut state, mut out) = (State::default(), Vec::new());
+        sky.draws(
+            0,
+            &noon("minecraft:desert"),
+            0.0,
+            0.05,
+            &mut state,
+            &mut out,
+        );
+        assert_eq!(
+            out.iter().map(|d| d.brightness).collect::<Vec<_>>(),
+            [1.0, 1.0]
+        );
+        // Out of the desert: the first layer fades over its two seconds.
+        sky.draws(0, &noon("minecraft:plains"), 0.0, 0.5, &mut state, &mut out);
+        assert_eq!(out[0].brightness, 0.75);
+        assert_eq!(out[1].blend, Blend::Alpha);
+        sky.draws(0, &noon("minecraft:plains"), 0.0, 2.0, &mut state, &mut out);
+        assert_eq!(out.len(), 1, "a dark layer is not drawn");
+        assert_eq!(out[0].image, 1);
+        // Into the End, which has no layers, and back: no fade.
+        sky.draws(1, &noon("minecraft:desert"), 0.0, 0.0, &mut state, &mut out);
+        assert!(out.is_empty());
+        sky.draws(0, &noon("minecraft:desert"), 0.0, 0.0, &mut state, &mut out);
+        assert_eq!(out.len(), 2);
+    }
+
+    #[test]
+    fn a_layer_turns_west_like_the_sun() {
+        let (root, sky) = pack(&[("sky1", "")]);
+        let _ = std::fs::remove_dir_all(root);
+        let (mut state, mut out) = (State::default(), Vec::new());
+        // A quarter turn after noon (sunset): the skybox's zenith has gone down to the west.
+        let c = Conditions {
+            day_time: 12000,
+            ..noon("minecraft:plains")
+        };
+        sky.draws(0, &c, 0.25, 0.0, &mut state, &mut out);
+        let up = out[0].rotation.transform_vector3(Vec3::Y);
+        assert!((up - Vec3::NEG_X).length() < 1e-5, "{up}");
+    }
+}

crates/horizon-client-render/src/effects.rs

@@ -14,6 +14,8 @@ pub struct EffectInstance {
     pub amplifier: i32,
     pub ambient: bool,
     pub visible: bool,
+    /// `MobEffectInstance.showIcon`: whether the HUD and inventory list it.
+    pub show_icon: bool,
     pub hidden: Option<Box<EffectInstance>>,
 }
 impl EffectInstance {
@@ -24,9 +26,18 @@ impl EffectInstance {
             amplifier: amplifier.clamp(0, 255),
             ambient: false,
             visible: true,
+            show_icon: true,
             hidden: None,
         }
     }
+    /// `new MobEffectInstance(effect, duration, amplifier, ambient, visible)`:
+    /// the icon shows exactly when the particles do.
+    pub fn with_flags(mut self, ambient: bool, visible: bool) -> Self {
+        self.ambient = ambient;
+        self.visible = visible;
+        self.show_icon = visible;
+        self
+    }
     fn infinite(&self) -> bool {
         self.duration == -1
     }
@@ -71,6 +82,10 @@ impl EffectInstance {
             self.visible = take.visible;
             changed = true;
         }
+        if take.show_icon != self.show_icon {
+            self.show_icon = take.show_icon;
+            changed = true;
+        }
         changed
     }
     /// `MobEffectInstance.tickClient`: a client counts its effects down
@@ -98,6 +113,7 @@ impl EffectInstance {
             self.amplifier = h.amplifier;
             self.ambient = h.ambient;
             self.visible = h.visible;
+            self.show_icon = h.show_icon;
             self.hidden = h.hidden;
         }
     }
@@ -171,6 +187,57 @@ pub enum OmenTick {
     /// It added this effect, then returned false.
     Add(EffectInstance),
 }
+/// A saved player's effect: `MobEffectInstance.Details` under its `id`.
+#[derive(Clone, Debug, PartialEq)]
+pub struct SavedEffect {
+    pub id: String,
+    pub duration: i32,
+    pub amplifier: i32,
+    pub ambient: bool,
+    /// `show_particles`.
+    pub particles: bool,
+    /// `show_icon`.
+    pub icon: bool,
+    /// `hidden_effect`: the weaker, longer instance of the same effect that
+    /// comes back when this one ends.
+    pub hidden: Option<Box<SavedEffect>>,
+}
+impl SavedEffect {
+    /// Ambient off, particles and icon shown, nothing hidden: the codec's
+    /// defaults.
+    pub fn new(id: impl Into<String>, duration: i32, amplifier: i32) -> Self {
+        Self {
+            id: id.into(),
+            duration,
+            amplifier,
+            ambient: false,
+            particles: true,
+            icon: true,
+            hidden: None,
+        }
+    }
+    fn of(e: &EffectInstance) -> Self {
+        Self {
+            id: potions::namespaced(e.id).to_owned(),
+            duration: e.duration,
+            amplifier: e.amplifier,
+            ambient: e.ambient,
+            particles: e.visible,
+            icon: e.show_icon,
+            hidden: e.hidden.as_deref().map(|h| Box::new(Self::of(h))),
+        }
+    }
+    /// `new MobEffectInstance(effect, details)`: the hidden chain comes back
+    /// with it.
+    fn instance(&self, id: &'static str) -> EffectInstance {
+        let mut e = EffectInstance::new(id, self.duration, self.amplifier);
+        e.ambient = self.ambient;
+        e.visible = self.particles;
+        e.show_icon = self.icon;
+        e.hidden = self.hidden.as_deref().map(|h| Box::new(h.instance(id)));
+        e
+    }
+}
 #[derive(Clone, Debug, Default)]
 pub struct PlayerEffects {
     pub list: Vec<EffectInstance>,
@@ -203,39 +270,25 @@ impl PlayerEffects {
     pub fn clear(&mut self) {
         self.list.clear();
     }
-    /// The effects of a saved player (`Player.active_effects`: id,
-    /// duration, amplifier, ambient, particles visible).
-    pub fn from_saved(saved: &[(String, i32, i32, bool, bool)]) -> Self {
+    /// The effects of a saved player (`Player.active_effects`), each with
+    /// the instances it hides.
+    pub fn from_saved(saved: &[SavedEffect]) -> Self {
         let mut effects = Self::default();
-        for (id, duration, amplifier, ambient, particles) in saved {
-            if let Some(def) = potions::effect(id) {
-                let mut e = EffectInstance::new(def.id, *duration, *amplifier);
-                e.ambient = *ambient;
-                e.visible = *particles;
-                effects.add(e);
+        for s in saved {
+            if let Some(def) = potions::effect(&s.id) {
+                effects.add(s.instance(def.id));
             }
         }
         effects
     }
     /// `Player.active_effects` for the save.
-    pub fn saved(&self) -> Vec<(String, i32, i32, bool, bool)> {
-        self.list
-            .iter()
-            .map(|e| {
-                (
-                    potions::namespaced(e.id).to_owned(),
-                    e.duration,
-                    e.amplifier,
-                    e.ambient,
-                    e.visible,
-                )
-            })
-            .collect()
+    pub fn saved(&self) -> Vec<SavedEffect> {
+        self.list.iter().map(SavedEffect::of).collect()
     }
     /// ClientboundUpdateMobEffectPacket's flags without blending: ambient,
-    /// particles visible and the icon shown (always, for these effects).
+    /// particles visible and the icon shown.
     pub fn flags(e: &EffectInstance) -> i8 {
-        i8::from(e.ambient) | i8::from(e.visible) << 1 | 4
+        i8::from(e.ambient) | i8::from(e.visible) << 1 | i8::from(e.show_icon) << 2
     }
     /// `LivingEntity.tickEffects` (server part) with the omens' effect ticks:
     /// `omen` answers `BadOmenMobEffect` (every tick), `RaidOmenMobEffect`
@@ -536,6 +589,36 @@ mod tests {
         );
     }
 
+    /// Warden darkness (`new MobEffectInstance(DARKNESS, 260, 0, false,
+    /// false)`) shows neither particles nor its icon; a renewal that shows the
+    /// icon turns it back on (`MobEffectInstance.update`).
+    #[test]
+    fn an_effect_without_particles_hides_its_icon() {
+        let mut fx = PlayerEffects::default();
+        fx.add(EffectInstance::new("darkness", 260, 0).with_flags(false, false));
+        let darkness = fx.get("darkness").unwrap();
+        // ClientboundUpdateMobEffectPacket: no ambient, particles or icon bit.
+        assert_eq!(PlayerEffects::flags(darkness), 0);
+        assert!(!crate::hud_overlays::EffectIcon::from(darkness).show_icon);
+        assert!(fx.add(EffectInstance::new("darkness", 100, 0)));
+        assert_eq!(PlayerEffects::flags(fx.get("darkness").unwrap()), 2 | 4);
+
+        // Details keeps show_icon apart from show_particles.
+        let mut speed = EffectInstance::new("speed", 100, 0);
+        speed.show_icon = false;
+        let mut fx = PlayerEffects::default();
+        fx.add(speed);
+        let saved = fx.saved();
+        assert_eq!(
+            saved,
+            [SavedEffect {
+                icon: false,
+                ..SavedEffect::new("minecraft:speed", 100, 0)
+            }]
+        );
+        let loaded = PlayerEffects::from_saved(&saved);
+        assert_eq!(PlayerEffects::flags(loaded.get("speed").unwrap()), 2);
+    }
     #[test]
     fn adding_counts_a_change_only_when_the_effect_changed() {
         let mut fx = PlayerEffects::default();
@@ -572,6 +655,21 @@ mod tests {
         assert_eq!(fx.get("speed").unwrap().duration, 49);
         assert_eq!(fx.get("raid_omen").unwrap().amplifier, 1);
     }
+    #[test]
+    fn a_reloaded_effect_falls_back_to_the_one_it_hid() {
+        // /effect give poison 6 s level II over poison 30 s level I, saved
+        // and loaded: when level II runs out, level I resumes with what is
+        // left of its 30 s.
+        let mut fx = PlayerEffects::default();
+        fx.add(EffectInstance::new("poison", 600, 0));
+        fx.add(EffectInstance::new("poison", 120, 1));
+        let mut loaded = PlayerEffects::from_saved(&fx.saved());
+        for _ in 0..120 {
+            loaded.tick();
+        }
+        let poison = loaded.get("poison").expect("level I resumed");
+        assert_eq!((poison.amplifier, poison.duration), (0, 480));
+    }
     /// The only test here that registers mod effects (once per process).
     #[test]
     fn a_mod_effect_saves_under_its_namespace() {
@@ -587,11 +685,11 @@ mod tests {
             1,
         ));
         let saved = fx.saved();
-        assert_eq!(saved, [("ruby:glow".to_owned(), 600, 1, false, true)]);
+        assert_eq!(saved, [SavedEffect::new("ruby:glow", 600, 1)]);
         assert_eq!(PlayerEffects::from_saved(&saved).list, fx.list);
         // Without its mod the saved effect is dropped, as an unknown id is.
         assert!(
-            PlayerEffects::from_saved(&[("gone:glow".into(), 600, 1, false, true)])
+            PlayerEffects::from_saved(&[SavedEffect::new("gone:glow", 600, 1)])
                 .list
                 .is_empty()
         );

crates/horizon-client-render/src/extras_ui.rs

@@ -0,0 +1,231 @@
+//! The Horizon Extras page, on the settings shell (`settings_shell`): which rows it has and what
+//! pressing them does. Each one's value and what it does stay in `extras::Item`.
+use crate::{
+    extras::{self, Item},
+    lang,
+    options_ui::{Event, Page},
+    settings::Settings,
+    settings_shell::{Group, Output, Row, Screen, Sheet, Value},
+};
+
+const TITLE: &str = "horizon.pages.extras";
+const ABOUT: &str = "horizon.pages.extras.tooltip";
+/// The group of the mod that replaced an extra.
+const MODS: &str = "horizon.pages.mods";
+const ZOOM: &str = "horizon.extras.zoom";
+const ZOOM_INSTALL: &str = "horizon.extras.zoom_mod_install";
+const MOD_SETTINGS: &str = "horizon.mods.settings";
+/// Its descriptions run long, as tooltips they were: most need more than two lines.
+const NOTE_LINES: usize = 5;
+/// The official native mod that took over from the Zoom extra (#8713).
+const ZOOM_ID: &str = "zoom";
+
+/// A row of the page.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub(crate) enum ExtraRow {
+    Item(Item),
+    /// The Zoom mod, at this place among the installed ones, on or off.
+    Zoom(usize),
+    /// Its own settings page.
+    ZoomSettings(usize),
+    /// It isn't installed: where to get it. A note, not a button: Options > Mods already has the
+    /// one way into the Mods page (`every_setting_and_page_is_reached_from_one_place`).
+    ZoomInstall,
+}
+
+fn item_row(item: Item, s: &Settings) -> Row<ExtraRow> {
+    let e = &s.extras;
+    let value = match (item.key_name(), item.switch(e)) {
+        (Some(key), _) => Value::Key(key, item.value(e)),
+        (None, Some(on)) => Value::Switch(on),
+        (None, None) => Value::Choice(item.value(e)),
+    };
+    // A setting of a switch that is off does nothing, so it is greyed out.
+    let live = item
+        .parent()
+        .is_none_or(|parent| parent.switch(e) != Some(false));
+    Row::new(ExtraRow::Item(item), item.caption_text(), value)
+        .about(item.description_text())
+        .live(live)
+}
+
+/// Zoom, the FPS counter, Keystrokes and the Minimap are official mods now; Extras keeps a way to
+/// the one players look for here.
+fn zoom_rows(s: &Settings) -> Vec<Row<ExtraRow>> {
+    let installed = &s.mods.installed;
+    let found = installed
+        .iter()
+        .position(|m| m.id == ZOOM_ID && m.native.is_some());
+    let Some(i) = found else {
+        let note = Row::new(ExtraRow::ZoomInstall, lang::get(ZOOM_INSTALL), Value::Note);
+        return vec![note.live(false)];
+    };
+    let about = installed[i].problem.as_ref();
+    let about = about.unwrap_or(&installed[i].description).clone();
+    let on = Value::Switch(s.mods.is_on(i));
+    let mut rows = vec![Row::new(ExtraRow::Zoom(i), lang::get(ZOOM), on).about(about)];
+    let page = installed[i].native.as_ref();
+    if page.is_some_and(|page| !page.keys.is_empty() || !page.buttons.is_empty()) {
+        let name = lang::get(MOD_SETTINGS);
+        rows.push(Row::new(ExtraRow::ZoomSettings(i), name, Value::Press));
+    }
+    rows
+}
+
+/// The page itself holds nothing: everything it shows is in the settings.
+#[derive(Default)]
+pub(crate) struct ExtrasScreen;
+
+impl Screen for ExtrasScreen {
+    type Page = ();
+    type Row = ExtraRow;
+    fn title(&self) -> &'static str {
+        TITLE
+    }
+    fn note_lines(&self) -> usize {
+        NOTE_LINES
+    }
+    fn sheets(&self, s: &Settings) -> Vec<Sheet<(), ExtraRow>> {
+        let mut groups = vec![Group {
+            name: MODS,
+            rows: zoom_rows(s),
+        }];
+        for row in extras::rows() {
+            match row {
+                Err(name) => groups.push(Group {
+                    name,
+                    rows: Vec::new(),
+                }),
+                Ok(item) => {
+                    if let Some(group) = groups.last_mut() {
+                        group.rows.push(item_row(item, s));
+                    }
+                }
+            }
+        }
+        vec![Sheet {
+            id: (),
+            name: lang::get(TITLE),
+            about: lang::get(ABOUT),
+            groups,
+        }]
+    }
+    fn press(&mut self, s: &mut Settings, row: ExtraRow, back: bool) -> Vec<Output> {
+        match row {
+            ExtraRow::Item(item) => match item.key_name() {
+                Some(key) => vec![Output::BindKey(key)],
+                None => {
+                    item.cycle(&mut s.extras, back);
+                    vec![Output::Event(Event::Changed)]
+                }
+            },
+            ExtraRow::Zoom(i) => {
+                s.mods.toggle(i);
+                vec![Output::Event(Event::Changed)]
+            }
+            ExtraRow::ZoomSettings(i) => vec![
+                Output::Event(Event::ButtonClick),
+                Output::Push(Page::NativeMod(i)),
+                Output::Event(Event::NativeSettings(i)),
+            ],
+            ExtraRow::ZoomInstall => Vec::new(),
+        }
+    }
+    /// With the wheel extra on, the wheel over an item changes it, without a click; the mod's rows
+    /// let the list scroll.
+    fn wheel_step(&mut self, s: &mut Settings, row: ExtraRow, back: bool) -> Option<Vec<Output>> {
+        let ExtraRow::Item(item) = row else {
+            return None;
+        };
+        item.cycle(&mut s.extras, back);
+        Some(vec![Output::Event(Event::Changed)])
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::settings_shell::{Hosted, Shell};
+
+    const SIZE: (f32, f32) = (854.0, 480.0);
+
+    fn rows_of(s: &Settings) -> Vec<Row<ExtraRow>> {
+        let sheets = ExtrasScreen.sheets(s);
+        let groups = sheets.into_iter().flat_map(|sheet| sheet.groups);
+        groups.flat_map(|group| group.rows).collect()
+    }
+
+    /// Greyed exactly while its own switch is off, so it takes no press then.
+    #[test]
+    fn a_setting_of_a_switch_that_is_off_is_greyed_and_takes_no_press() {
+        let mut s = Settings::default();
+        let live = |s: &Settings| {
+            let wheel = ExtraRow::Item(Item::MouseTweaksWheel);
+            rows_of(s).iter().find(|r| r.id == wheel).unwrap().live
+        };
+        s.extras.mouse_tweaks = false;
+        assert!(!live(&s));
+        let mut shell = Shell::<ExtrasScreen>::default();
+        let row = ExtraRow::Item(Item::MouseTweaksWheel);
+        let at = shell.point_at(&s, SIZE, row);
+        let before = s.extras.mouse_tweaks_wheel;
+        assert!(
+            shell
+                .click(&mut s, at, SIZE, false, false, false)
+                .is_empty()
+        );
+        assert_eq!(s.extras.mouse_tweaks_wheel, before);
+        s.extras.mouse_tweaks = true;
+        assert!(live(&s));
+        assert!(
+            !shell
+                .click(&mut s, at, SIZE, false, false, false)
+                .is_empty()
+        );
+        assert_ne!(s.extras.mouse_tweaks_wheel, before);
+    }
+
+    #[test]
+    fn the_three_way_cosmetics_row_turns_both_ways() {
+        use horizon_cosmetics::prefs::Others;
+        let mut s = Settings::default();
+        let mut screen = ExtrasScreen;
+        let row = ExtraRow::Item(Item::CosmeticsOthers);
+        // Not chosen, nothing owned: it shows Hidden, and forward wraps to Shown.
+        assert_eq!(s.extras.effective_others(), Others::Hidden);
+        screen.press(&mut s, row, false);
+        assert_eq!(s.extras.cosmetics_others, Some(Others::Shown));
+        screen.press(&mut s, row, true);
+        assert_eq!(s.extras.cosmetics_others, Some(Others::Hidden));
+        screen.press(&mut s, row, true);
+        assert_eq!(s.extras.cosmetics_others, Some(Others::NameTags));
+    }
+
+    /// The sort key binds instead of cycling; the wheel leaves it be.
+    #[test]
+    fn the_key_row_waits_for_a_key() {
+        let mut s = Settings::default();
+        let mut screen = ExtrasScreen;
+        let row = ExtraRow::Item(Item::SortKey);
+        let key = s.extras.sort_key.clone();
+        assert_eq!(
+            screen.press(&mut s, row, false),
+            vec![Output::BindKey(extras::SORT_KEY)]
+        );
+        screen.wheel_step(&mut s, row, true);
+        assert_eq!(s.extras.sort_key, key);
+    }
+
+    #[test]
+    fn the_wheel_flips_a_switch_and_leaves_the_mod_to_scroll() {
+        let mut s = Settings::default();
+        let mut screen = ExtrasScreen;
+        let row = ExtraRow::Item(Item::Sort);
+        assert_eq!(
+            screen.wheel_step(&mut s, row, true),
+            Some(vec![Output::Event(Event::Changed)])
+        );
+        assert!(s.extras.sort);
+        assert_eq!(screen.wheel_step(&mut s, ExtraRow::Zoom(0), true), None);
+    }
+}

crates/horizon-client-render/src/fluid_render.rs

@@ -0,0 +1,210 @@
+// Still-fluid tiling follows Catnip/Ponder 1.0.82 FluidRenderHelper.renderTiledFace.
+// Copyright (c) 2022 The Create Team
+//
+// 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.
+
+use horizon_core::geometry::Direction;
+
+/// Controls a still-fluid box. The tint is stack ARGB, independent of biome tint.
+#[derive(Clone, Copy, Debug)]
+pub struct NativeFluidRenderOptions {
+    pub argb: Option<u32>,
+    pub render_bottom: bool,
+    /// TextureAtlasSprite.uvShrinkRatio: 4 / the largest stitched atlas dimension.
+    /// Explicit because Horizon's block sprites occupy arrays rather than a stitched atlas.
+    pub uv_shrink_ratio: f32,
+}
+
+/// A corner before the caller's pose, with UVs within the still sprite, and its outward normal.
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub struct FluidVertex {
+    pub pos: [f32; 3],
+    pub uv: [f32; 2],
+    pub normal: [i8; 3],
+}
+
+/// Preserve sky light and increase block light to the fluid's luminosity (native light packing).
+pub fn fluid_light(light: u32, luminosity: u8) -> u32 {
+    (light & 0xf0) | (((light >> 8 & 0xf0).max(u32::from(luminosity.min(15)) * 16)) << 8)
+}
+
+/// Emit whole tiled quads, or refuse invalid/unreasonably large geometry before emitting anything.
+/// Negative coordinates and exact integer boundaries retain the source's local UV fractions.
+pub fn fluid_box(
+    bounds: [f32; 6],
+    options: NativeFluidRenderOptions,
+    mut emit: impl FnMut(FluidVertex),
+) -> bool {
+    if !options.uv_shrink_ratio.is_finite()
+        || !(0.0..=1.0).contains(&options.uv_shrink_ratio)
+        || bounds
+            .iter()
+            .any(|x| !x.is_finite() || x.abs() > 1_048_576.0)
+        || (0..3).any(|i| bounds[i] > bounds[i + 3])
+    {
+        return false;
+    }
+    let tiles =
+        std::array::from_fn::<_, 3, _>(|i| (bounds[i + 3].ceil() - bounds[i].floor()) as u64);
+    let quads = tiles[0] * tiles[1] * 2
+        + tiles[1] * tiles[2] * 2
+        + tiles[0] * tiles[2] * if options.render_bottom { 2 } else { 1 };
+    if quads > 65_536 {
+        return false;
+    }
+    let [x0, y0, z0, x1, y1, z1] = bounds;
+    for (side, face) in [
+        (Direction::Down, [x0, z0, x1, z1, y0]),
+        (Direction::Up, [x0, z0, x1, z1, y1]),
+        (Direction::North, [x0, y0, x1, y1, z0]),
+        (Direction::South, [x0, y0, x1, y1, z1]),
+        (Direction::West, [z0, y0, z1, y1, x0]),
+        (Direction::East, [z0, y0, z1, y1, x1]),
+    ] {
+        if side != Direction::Down || options.render_bottom {
+            tiled_face(&mut emit, side, face, options.uv_shrink_ratio);
+        }
+    }
+    true
+}
+
+fn tiled_face(out: &mut impl FnMut(FluidVertex), side: Direction, face: [f32; 5], ratio: f32) {
+    let [a0, b0, a1, b1, plane] = face;
+    let positive = matches!(side, Direction::Up | Direction::South | Direction::East);
+    let shrink = ratio * 0.25;
+    let lerp = |v| v + shrink * (0.5 - v);
+    let mut a = a0;
+    while a < a1 {
+        let end_a = (a.floor() + 1.0).min(a1);
+        let (u0, u1) = if matches!(side, Direction::North | Direction::East) {
+            (end_a.ceil() - end_a, end_a.ceil() - a)
+        } else {
+            (a - a.floor(), end_a - a.floor())
+        };
+        let (u0, u1) = (lerp(u0), lerp(u1));
+        let mut b = b0;
+        while b < b1 {
+            let end_b = (b.floor() + 1.0).min(b1);
+            let (v0, v1) = if side == Direction::Up {
+                (b - b.floor(), end_b - b.floor())
+            } else {
+                (end_b.ceil() - end_b, end_b.ceil() - b)
+            };
+            let (v0, v1) = (lerp(v0), lerp(v1));
+            let positions = match side {
+                Direction::West | Direction::East => {
+                    let (near, far) = if positive { (end_a, a) } else { (a, end_a) };
+                    [
+                        [plane, end_b, near],
+                        [plane, b, near],
+                        [plane, b, far],
+                        [plane, end_b, far],
+                    ]
+                }
+                Direction::North | Direction::South => {
+                    let (near, far) = if positive { (a, end_a) } else { (end_a, a) };
+                    [
+                        [near, end_b, plane],
+                        [near, b, plane],
+                        [far, b, plane],
+                        [far, end_b, plane],
+                    ]
+                }
+                Direction::Down | Direction::Up => {
+                    let (near, far) = if positive { (b, end_b) } else { (end_b, b) };
+                    [
+                        [a, plane, near],
+                        [a, plane, far],
+                        [end_a, plane, far],
+                        [end_a, plane, near],
+                    ]
+                }
+            };
+            let normal = match side {
+                Direction::Down => [0, -1, 0],
+                Direction::Up => [0, 1, 0],
+                Direction::North => [0, 0, -1],
+                Direction::South => [0, 0, 1],
+                Direction::West => [-1, 0, 0],
+                Direction::East => [1, 0, 0],
+            };
+            for (pos, uv) in positions
+                .into_iter()
+                .zip([[u0, v0], [u0, v1], [u1, v1], [u1, v0]])
+            {
+                out(FluidVertex { pos, uv, normal });
+            }
+            b = end_b;
+        }
+        a = end_a;
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn source_tiling_is_outward_and_does_not_inset_geometry() {
+        let bounds = [-1.25, 0.125, -0.25, 1.5, 1.125, 0.75];
+        let mut result = Vec::new();
+        assert!(fluid_box(
+            bounds,
+            NativeFluidRenderOptions {
+                argb: None,
+                render_bottom: false,
+                uv_shrink_ratio: 4.0 / 2048.0,
+            },
+            |v| result.push(v),
+        ));
+        assert_eq!(result.len(), (4 * 2 * 2 + 2 * 2 * 2 + 4 * 2) * 4);
+        for quad in result.as_chunks::<4>().0 {
+            let [a, b, c, _] = quad.map(|v| glam::Vec3::from_array(v.pos));
+            assert!(
+                (b - a)
+                    .cross(c - a)
+                    .dot(glam::Vec3::from_array(quad[0].normal.map(f32::from)))
+                    > 0.0
+            );
+            assert!(
+                quad.iter()
+                    .all(|v| (0..3).all(|i| v.pos[i] >= bounds[i] && v.pos[i] <= bounds[i + 3]))
+            );
+        }
+        assert!(
+            result
+                .iter()
+                .any(|v| v.pos == [bounds[0], bounds[4], bounds[2]])
+        );
+        assert!(!fluid_box(
+            [0.0, 0.0, 0.0, 1_000.0, 1_000.0, 1_000.0],
+            NativeFluidRenderOptions {
+                argb: None,
+                render_bottom: true,
+                uv_shrink_ratio: 0.0,
+            },
+            |_| panic!("invalid geometry must fail before emitting"),
+        ));
+    }
+    #[test]
+    fn luminosity_changes_only_block_light() {
+        assert_eq!(fluid_light(0x20a0, 15), 0xf0a0);
+        assert_eq!(fluid_light(0x25a5, 15), 0xf0a0);
+        assert_eq!(fluid_light(0xe030, 3), 0xe030);
+    }
+}

crates/horizon-client-render/src/fog.rs

@@ -413,6 +413,12 @@ pub fn clear_distance_fog(fog: &mut FogData, input: &FogInputs) {
         (fog.environmental_start, fog.environmental_end) = (1e9, 2e9);
     }
 }
+/// What `AtmosphericFogEnvironment.updateRainFogState` eases the rain fog toward: the rain, where
+/// the sky reaches the eye, halved in a biome without precipitation.
+pub fn rain_fog_target(rain: f32, sky_light: u8, biome_rains: bool) -> f32 {
+    let sky = ((f32::from(sky_light) - 8.0) / 7.0).clamp(0.0, 1.0);
+    rain * sky * if biome_rains { 1.0 } else { 0.5 }
+}
 /// Whether the frame draws no sky, only the clear to the fog colour: `LevelRenderer.addSkyPass`
 /// leaves the sky out in lava and powder snow and while blindness or darkness is on (`Camera`'s
 /// `doesMobEffectBlockSky`), and `GameRenderer.renderLevel` gives `LevelRenderer.render`
@@ -428,10 +434,14 @@ pub fn update_rain_fog(
     biome_rains: bool,
     delta_ticks: f32,
 ) {
-    let sky = ((f32::from(sky_light) - 8.0) / 7.0).clamp(0.0, 1.0);
-    let target = rain * sky * if biome_rains { 1.0 } else { 0.5 };
+    let target = rain_fog_target(rain, sky_light, biome_rains);
     state.rain_fog_multiplier += (target - state.rain_fog_multiplier) * delta_ticks * 0.2;
 }
+/// The rain fog at its target at once: a frozen world under `HORIZON_STILL`, where the rain sits
+/// at its level and easing would wait for ticks that do not come.
+pub fn settle_rain_fog(state: &mut FogState, rain: f32, sky_light: u8, biome_rains: bool) {
+    state.rain_fog_multiplier = rain_fog_target(rain, sky_light, biome_rains);
+}
 fn rgb(c: u32) -> [f32; 3] {
     [
         (c >> 16 & 255) as f32 / 255.0,
@@ -726,6 +736,30 @@ mod tests {
         assert_eq!(clear.environmental_end, settled.environmental_end);
         assert_eq!(clear.color, settled.color);
     }
+    /// Settling puts the rain fog at its target exactly, where a tick of easing moves it a fifth
+    /// of the way, as before.
+    #[test]
+    fn settled_rain_fog_is_its_target_and_easing_is_unchanged() {
+        assert_eq!(
+            rain_fog_target(1.0, 15, false),
+            0.5,
+            "a dry biome halves it"
+        );
+        assert_eq!(rain_fog_target(1.0, 8, true), 0.0, "no sky, no rain fog");
+        let start = FogState {
+            rain_fog_multiplier: 0.1,
+            ..FogState::default()
+        };
+        let mut settled = start;
+        settle_rain_fog(&mut settled, 0.5, 15, true);
+        assert_eq!(settled.rain_fog_multiplier, 0.5);
+        let mut eased = start;
+        update_rain_fog(&mut eased, 0.5, 15, true, 1.0);
+        assert_eq!(
+            eased.rain_fog_multiplier.to_bits(),
+            (0.1f32 + (0.5f32 - 0.1) * 1.0 * 0.2).to_bits()
+        );
+    }
     #[test]
     fn rain_fog_pulls_fog_in() {
         let sky = Sky {

crates/horizon-client-render/src/gfx.rs

@@ -45,18 +45,21 @@ fn static_entity_shader() -> String {
 mod crumbling_tests;
 mod entity_batch;
 mod entity_outline;
+mod fluid;
 #[cfg(test)]
 mod inter_stage_tests;
+mod terrain_model;
 #[cfg(test)]
 pub(crate) mod test_gpu;
 mod weather;
 mod world_text;
 use entity_batch::EntityBatch;
 pub use entity_batch::{
-    DISSOLVE_OVERLAY, DRAGON_RAYS_OVERLAY, ENERGY_SWIRL_OVERLAY, OIT_ENTITY, SHADOW_OVERLAY,
-    TEXT_POLYGON_OFFSET_OVERLAY, TRANSLUCENT_GLINT_ITEM_OVERLAY, TRANSLUCENT_ITEM_OVERLAY,
-    TRANSLUCENT_PARTICLE_OVERLAY, WATER_MASK_OVERLAY, WORLD_TEXT_OVERLAY,
-    WORLD_TEXT_POLYGON_OFFSET_OVERLAY, mark_oit,
+    DISSOLVE_OVERLAY, DRAGON_RAYS_OVERLAY, ENERGY_SWIRL_OVERLAY, FLUID_OVERLAY, OIT_ENTITY,
+    SHADOW_OVERLAY, TERRAIN_MODEL_CUTOUT_MIPPED_OVERLAY, TERRAIN_MODEL_CUTOUT_OVERLAY,
+    TERRAIN_MODEL_SOLID_OVERLAY, TEXT_POLYGON_OFFSET_OVERLAY, TRANSLUCENT_GLINT_ITEM_OVERLAY,
+    TRANSLUCENT_ITEM_OVERLAY, TRANSLUCENT_PARTICLE_OVERLAY, WATER_MASK_OVERLAY, WORLD_TEXT_OVERLAY,
+    WORLD_TEXT_POLYGON_OFFSET_OVERLAY, is_native_terrain, mark_oit,
 };
 pub use view::{View, ViewSet};
 
@@ -170,6 +173,7 @@ mod hdr_icc;
 mod hdr_stats;
 pub use hdr::Calibration as HdrCalibration;
 pub mod block_light;
+mod custom_sky;
 mod displace;
 pub mod lightning;
 mod lod;
@@ -227,6 +231,13 @@ fn sky_visible(frame: &Frame) -> bool {
     !frame.title && frame.skybox && sky_open(frame)
 }
 
+/// The End during the dragon fight, whose world fog leaves out vanilla's sky: a shader pack's
+/// `gbuffers_skybasic` still draws a fan around the horizon (`pack_sky`), as our probe packs read
+/// it in Iris 1.11.7.
+fn end_fog_sky(frame: &Frame) -> bool {
+    !frame.title && frame.end_sky && frame.boss_world_fog
+}
+
 /// The world pass's part that draws a shader pack's solid terrain: the world's colour and
 /// depth loaded, and its `surface` target, cleared on the first of these passes.
 fn surface_pass<'e>(
@@ -469,9 +480,9 @@ struct SectionGpu {
     /// while its instance carries a fade (`drawn_faded`), and GPU culling's
     /// pass leaves it out.
     gpu_fading: bool,
-    /// When it began to fade in over the far terrain it replaces, which
-    /// stays whole behind it until then: a section new where far tiles are
-    /// drawn. Meshed again, it stays as it was.
+    /// When it came in over the far terrain it replaces (drawn whole at once,
+    /// `fade`): a section new where far tiles are drawn, which skips vanilla's
+    /// fade-in. Meshed again, it stays as it was.
     fading: Option<std::time::Instant>,
     /// When it began to fade out, its column gone over far terrain that
     /// stays behind it (`Renderer::leave_section`); released once it has.
@@ -493,17 +504,19 @@ pub(crate) fn collect_animated_layers(
 }
 
 impl SectionGpu {
-    /// Its fade code this frame (`lod::fade_code`), 0 once whole. `retiring`:
-    /// its column has left the render distance, far terrain is coming in
-    /// under it (`lod::HELD`).
-    fn fade(&self, now: std::time::Instant, retiring: bool) -> u32 {
-        match self.leaving {
-            Some(since) => lod::fade_out_code(since, 0, now),
-            None if retiring => lod::HELD,
-            None => self
-                .fading
-                .and_then(|since| lod::fade_code(Some(since), 0, now))
-                .unwrap_or(0),
+    /// Its fade code this frame: 0, drawn whole, or `lod::HELD` (whole, in
+    /// front of far terrain) while it leaves (`leaving`) or its column has left
+    /// the render distance and far terrain is coming in under it (`retiring`).
+    /// A near section never dithers over far terrain: the holes of its pattern
+    /// showed its own inside (cave walls, the stone under the grass), nearer
+    /// than the tile behind, an x-ray of each column coming in or going out.
+    /// It comes in whole over the tile it replaces, which stays behind it until
+    /// `fading` is `lod::FADE` old, and leaves whole after as long.
+    fn fade(&self, retiring: bool) -> u32 {
+        if self.leaving.is_some() || retiring {
+            lod::HELD
+        } else {
+            0
         }
     }
     /// Its vertices in `arena`, and in `translucent_arena` when `split` (there
@@ -569,23 +582,21 @@ impl SectionGpu {
     /// once false, this stays false until the section is meshed again, leaves,
     /// is held (`lod_retiring`), or the chunk fade-in time changes.
     fn drawn_faded(&self, key: SectionKey, f: FadeInputs<'_>) -> bool {
-        let fade = self.fade(f.now, f.retiring.contains(&key));
+        let fade = self.fade(f.retiring.contains(&key));
         let visibility = section_visibility(f.uploaded.get(&key), f.fade_ms, f.now);
         section_instance([0.0; 3], fade, visibility)[3].to_bits()
             != section_instance([0.0; 3], 0, 1.0)[3].to_bits()
     }
-    /// When its fade is over at the latest (`drawn_faded`): the later of the
-    /// ends of its fade-in over far terrain (`fading` and `lod::FADE`, a few
-    /// milliseconds after `fade` reaches 0) and of vanilla's (its first upload
-    /// and `f.fade_ms`). None while it leaves or is held, which ends only when
-    /// it goes or is meshed again, and without either fade-in.
+    /// When its fade is over at the latest (`drawn_faded`): the end of
+    /// vanilla's fade-in (its first upload and `f.fade_ms`; one coming in over
+    /// far terrain is whole at once, `fade`). None while it leaves or is held,
+    /// which ends only when it goes or is meshed again, and without a fade-in.
     fn fade_end(&self, key: SectionKey, f: FadeInputs<'_>) -> Option<Instant> {
         if self.leaving.is_some() || f.retiring.contains(&key) {
             return None;
         }
         let vanilla = f.uploaded.get(&key).filter(|_| f.fade_ms > 0);
-        let vanilla = vanilla.map(|&t| t + std::time::Duration::from_millis(f.fade_ms));
-        vanilla.max(self.fading.map(|t| t + lod::FADE))
+        vanilla.map(|&t| t + std::time::Duration::from_millis(f.fade_ms))
     }
 }
 /// Which of a mesh's ranges `move_off_page` moves: what it holds in the section
@@ -883,6 +894,8 @@ pub struct Frame<'a> {
     pub end_sky: bool,
     /// End sky atlas bounds (u0, v0, u1, v1); absent when the sprite is missing.
     pub end_sky_sprite: Option<[f32; 4]>,
+    /// A boss bar makes world fog (`BossHealthOverlay.shouldCreateWorldFog`: the Ender Dragon's).
+    pub boss_world_fog: bool,
     /// Environmental fog start/end (Nether 10..96), if any.
     pub environment_fog: Option<(f32, f32)>,
     pub water_fog: [f32; 3],
@@ -1204,10 +1217,15 @@ pub struct Renderer {
     world_primitives: world_primitives::WorldPrimitives,
     text_polygon_offset_pipeline: wgpu::RenderPipeline,
     world_text_pipeline: wgpu::RenderPipeline,
+    fluid_pipeline: wgpu::RenderPipeline,
+    terrain_model_pipelines: [wgpu::RenderPipeline; 3],
     celestial_pipeline: wgpu::RenderPipeline,
     celestial_buffer: wgpu::Buffer,
     end_sky: end_sky::EndSky,
     stars: stars::Stars,
+    /// OptiFine custom sky layers (`crate::custom_sky`), and the frame's from the game.
+    custom_sky: custom_sky::CustomSky,
+    custom_sky_draws: Vec<crate::custom_sky::Draw>,
     /// The glowing entities' outline (`LevelRenderer.entityOutlineTarget`).
     entity_outline: entity_outline::EntityOutline,
     panorama: panorama::Panorama,
@@ -1236,6 +1254,10 @@ pub struct Renderer {
     /// Ordinary entity models posed on the GPU; `None` without compute shaders.
     entity_skin: Option<entity_skin::EntitySkin>,
     group: wgpu::BindGroup,
+    fluid_group: wgpu::BindGroup,
+    fluid_sampler: wgpu::Sampler,
+    terrain_model_group: wgpu::BindGroup,
+    terrain_model_sampler: wgpu::Sampler,
     globals: wgpu::Buffer,
     /// Resource-pack normal/specular maps, split like the colour sprite arrays.
     pbr_maps: Option<Vec<[wgpu::Texture; 2]>>,
@@ -1471,6 +1493,8 @@ pub struct Renderer {
     pub screenshot: Option<ScreenshotRequest>,
     /// Outcome of the last screenshot: frame size, or the error.
     pub screenshot_result: Option<std::result::Result<[u32; 2], String>>,
+    /// The HDR copy the last screenshot wrote beside it, if it wrote one.
+    pub screenshot_hdr: Option<std::path::PathBuf>,
     /// Screenshot Quality (Horizon setting): a `scaled` screenshot's frame is this many
     /// times the game's resolution (1, 2, 4 or 8).
     pub screenshot_quality: u32,
@@ -2022,24 +2046,26 @@ fn draws_frame(format: wgpu::TextureFormatFeatures) -> bool {
     )
 }
 
-/// The frame of a renderer made with a shader API 0.2 pack picked under
-/// `HORIZON_HDR_FRAME=float` (docs/design/hdr-linear-light.md): float, so values over 1
-/// survive from the world to the tonemap.
+/// The frame of a renderer made under `HORIZON_HDR_FRAME=float` (docs/design/hdr-linear-light.md)
+/// with a shader API 0.2 pack picked, or with HDR on and no pack: float, so values over 1
+/// survive from the world to the tonemap and the HDR pass.
 const LINEAR_FRAME: wgpu::TextureFormat = wgpu::TextureFormat::Rgba16Float;
 
-/// What a renderer's frame is drawn in: `LINEAR_FRAME` for a 0.2 pack under the switch
-/// (`linear`: `(picked, the device draws it)`); else `WIDE_FRAME` when it is made with HDR on
-/// and Smooth Gradients (`wide_frame`, `Graphics::wide_frame`), the surface offering HDR output
-/// (`hdr_offered`) and the device drawing it (`draws_wide_frame`): an 8-bit frame's steps band
-/// in dark gradients, and HDR shows them. Else the swapchain's 8-bit format, as without HDR.
+/// What a renderer's frame is drawn in: `LINEAR_FRAME` under the switch where the device draws
+/// it, for a 0.2 pack, or for HDR on without a pack where the surface offers HDR output
+/// (`linear`: `(a 0.2 pack picked, HDR on without a pack, the device draws it)`); else
+/// `WIDE_FRAME` when it is made with HDR on and Smooth Gradients (`wide_frame`,
+/// `Graphics::wide_frame`), the surface offering HDR output (`hdr_offered`) and the device
+/// drawing it (`draws_wide_frame`): an 8-bit frame's steps band in dark gradients, and HDR
+/// shows them. Else the swapchain's 8-bit format, as without HDR.
 fn frame_format(
     wide_frame: bool,
     hdr_offered: bool,
     device_draws_it: bool,
     swapchain: wgpu::TextureFormat,
-    linear: (bool, bool),
+    linear: (bool, bool, bool),
 ) -> wgpu::TextureFormat {
-    if linear.0 && linear.1 {
+    if linear.2 && (linear.0 || linear.1 && hdr_offered) {
         LINEAR_FRAME
     } else if wide_frame && hdr_offered && device_draws_it {
         WIDE_FRAME
@@ -2516,6 +2542,7 @@ impl Renderer {
         wide_frame: bool,
         shader_pack: bool,
         linear_pack: bool,
+        hdr_float: bool,
     ) -> Result<Self> {
         let Opened {
             instance,
@@ -2651,9 +2678,10 @@ impl Renderer {
         crate::graphics::offer_smooth_gradients(wide_ok);
         let linear = (
             linear_pack,
+            hdr_float,
             draws_frame(adapter.get_texture_format_features(LINEAR_FRAME)),
         );
-        if linear == (true, false) {
+        if linear.0 && !linear.2 {
             log::warn!(
                 "Horizon renderer: the device can't draw a float frame; the shader API 0.2 pack runs on the 8-bit one"
             );
@@ -2763,6 +2791,20 @@ impl Renderer {
             bind_group_layouts: &[Some(&bindings)],
             ..Default::default()
         });
+        let fluid_pipeline = fluid::pipeline(
+            &device,
+            Some(&layout),
+            &shader,
+            config.format.remove_srgb_suffix(),
+            &sprite_constants,
+        );
+        let terrain_model_pipelines = terrain_model::pipelines(
+            &device,
+            Some(&layout),
+            &shader,
+            config.format.remove_srgb_suffix(),
+            &sprite_constants,
+        );
         let instance_attributes = wgpu::vertex_attr_array![5=>Float32x4];
         let terrain_buffers = [
             Some(wgpu::VertexBufferLayout {
@@ -3321,6 +3363,34 @@ impl Renderer {
             &lightmap_sampler,
             &emission_stats.view,
         );
+        let fluid_sampler = device.create_sampler(&fluid::SAMPLER);
+        let fluid_group = terrain_group(
+            &device,
+            "Still fluid resources",
+            &bindings,
+            &globals,
+            &sprite_views,
+            &fluid_sampler,
+            &lightmap_view,
+            &lightmap_sampler,
+            &emission_stats.view,
+        );
+        let terrain_model_sampler = device.create_sampler(&wgpu::SamplerDescriptor {
+            label: Some("Native cutout model (unmipped)"),
+            lod_max_clamp: 0.0,
+            ..fluid::SAMPLER
+        });
+        let terrain_model_group = terrain_group(
+            &device,
+            "Native cutout model resources",
+            &bindings,
+            &globals,
+            &sprite_views,
+            &terrain_model_sampler,
+            &lightmap_view,
+            &lightmap_sampler,
+            &emission_stats.view,
+        );
         let crosshair_group = terrain_group(
             &device,
             "Debug crosshair resources",
@@ -3888,12 +3958,8 @@ impl Renderer {
             alpha_blend,
             false,
         );
-        let world_text_pipeline = world_text::pipeline(
-            &device,
-            Some(&entity_layout),
-            &entity_shader,
-            config.format.remove_srgb_suffix(),
-        );
+        let world_text_pipeline =
+            world_text::pipeline(&device, Some(&entity_layout), &entity_shader, frame_format);
         // RenderPipelines.ENTITY_SOLID: a surface of an entity that is coplanar with
         // terrain wins the tie in vanilla (the boat's floor over the trapdoor on the
         // ground it is stopped by, #5950). Terrain and entities are separate draw
@@ -4595,6 +4661,7 @@ impl Renderer {
         let uploads = upload::Uploads::new(&device);
         let section_uploads = upload::Uploads::with_chunk(&device, SECTION_UPLOAD_CHUNK);
         let stars = stars::Stars::new(&device, frame_format);
+        let custom_sky = custom_sky::CustomSky::new(&device, frame_format);
         let entity_outline = entity_outline::EntityOutline::new(
             &device,
             (&entity_shader, &entity_layout, &entity_vertex),
@@ -4713,10 +4780,14 @@ impl Renderer {
             world_primitives,
             text_polygon_offset_pipeline,
             world_text_pipeline,
+            fluid_pipeline,
+            terrain_model_pipelines,
             celestial_pipeline,
             celestial_buffer,
             end_sky: end_sky::EndSky::default(),
             stars,
+            custom_sky,
+            custom_sky_draws: Vec::new(),
             entity_outline,
             panorama,
             border_pipeline,
@@ -4743,6 +4814,10 @@ impl Renderer {
             entity_batch: EntityBatch::default(),
             entity_skin,
             group,
+            fluid_group,
+            fluid_sampler,
+            terrain_model_group,
+            terrain_model_sampler,
             globals,
             pbr_maps,
             lightmap,
@@ -4863,6 +4938,7 @@ impl Renderer {
             started: Instant::now(),
             screenshot: None,
             screenshot_result: None,
+            screenshot_hdr: None,
             screenshot_quality: 1,
             screenshot_halvings: 0,
             gamma: 0.5,
@@ -4933,6 +5009,15 @@ impl Renderer {
         }
         pass.set_index_buffer(self.indices.slice(..), wgpu::IndexFormat::Uint32);
     }
+    /// The pack's OptiFine custom sky layer textures (`crate::custom_sky::CustomSky::load`).
+    pub fn set_custom_sky(&mut self, pack: &crate::custom_sky::CustomSky) {
+        self.custom_sky.set_pack(&self.device, &self.queue, pack);
+    }
+    /// The custom sky layers the next frame draws (`CustomSky::draws`): the game refills it each
+    /// frame, empty when the world's sky has none.
+    pub fn custom_sky_draws(&mut self) -> &mut Vec<crate::custom_sky::Draw> {
+        &mut self.custom_sky_draws
+    }
     /// The resource packs' `core/rendertype_lines` (`HudAtlas::lines_shader`) for the block
     /// outline, or the built-in one.
     pub fn set_lines_shader(&mut self, program: Option<&horizon_shaders::CoreProgram>) {
@@ -6584,6 +6669,7 @@ impl Renderer {
                 post,
                 self.frame_format,
                 world,
+                &std::sync::atomic::AtomicBool::new(false),
             )
         });
         self.pack_loading = None;
@@ -6615,6 +6701,50 @@ impl Renderer {
         }
         Ok(report)
     }
+    /// Makes the running shader pack, of either kind, forget what it kept from earlier frames:
+    /// the next frame draws as a freshly loaded pack's first. Nothing to do without a pack.
+    pub fn reset_shader_pack_history(&mut self) {
+        // A frame still on the submit thread uses the targets and readbacks replaced
+        // here.
+        self.land_frame();
+        if let Some((_, Some(post))) = &mut self.pack_post {
+            post.reset_history(&self.device);
+        }
+        if let Some(native) = &mut self.native {
+            native.frame.reset_history();
+            if let Some(post) = &mut native.post {
+                post.reset_history();
+            }
+        }
+    }
+    /// The running shader pack's kind: `iris` (a `shaders/` pack) or `native` (one of
+    /// Horizon's own).
+    pub fn shader_pack_kind(&self) -> Option<&'static str> {
+        match (&self.pack_post, &self.native) {
+            (Some((_, Some(_))), _) => Some("iris"),
+            (_, Some(_)) => Some("native"),
+            _ => None,
+        }
+    }
+    /// `screenshot-sequence`: waits (30 seconds at most) for the frame just drawn to finish on
+    /// the GPU, and takes the centre depth a `shaders/` pack copied in it, which its next frame
+    /// reads: that frame's, or an error, never an older one. The last frame's PNG has already
+    /// waited for it, without a limit, as `screenshot` does.
+    pub fn finish_sequence_frame(&mut self) -> Result<()> {
+        self.device
+            .poll(wgpu::PollType::Wait {
+                submission_index: None,
+                timeout: Some(std::time::Duration::from_secs(30)),
+            })
+            .map_err(|e| format!("the frame didn't finish on the GPU: {e}"))?;
+        if self.device_lost() {
+            return Err("the graphics device was lost".into());
+        }
+        if let Some((_, Some(post))) = &mut self.pack_post {
+            post.take_center_depth(&self.device)?;
+        }
+        Ok(())
+    }
     /// As `set_shader_pack` with a pack, but its pipelines build on a thread of their own while
     /// the game keeps drawing without one: the driver compiles a big pack's programs for seconds.
     /// `poll_shader_pack` runs it once they are built. `label` and `started` come back with it.
@@ -6656,6 +6786,8 @@ impl Renderer {
             .map(|f| f.draw_layout.clone());
         let terrain = self.pack_atlas.is_some();
         let clouds = self.cloud_bindings.clone();
+        let cancel = std::sync::Arc::new(std::sync::atomic::AtomicBool::new(false));
+        let cancelled = cancel.clone();
         let build = move || {
             let instance = wgpu::vertex_attr_array![5=>Float32x4];
             let vertex = wgpu::VertexBufferLayout {
@@ -6690,7 +6822,7 @@ impl Renderer {
                 weather: true,
                 hand: true,
             };
-            pack_post::PackPost::new(&device, &queue, &adapter, pack, format, world)
+            pack_post::PackPost::new(&device, &queue, &adapter, pack, format, world, &cancelled)
         };
         // A pack is not the game's code: a panic building it turns the pack off (#3525).
         let thread = std::thread::Builder::new()
@@ -6705,9 +6837,15 @@ impl Renderer {
                     thread,
                     label,
                     started,
+                    _cancel: CancelOnDrop(cancel),
                 });
             }
-            Err(e) => log::error!("shader pack {label}: no thread to build it on: {e}"),
+            Err(e) => {
+                log::error!("shader pack {label}: no thread to build it on: {e}");
+                // Off for this dimension, as a pack that fails, not tried again every frame.
+                self.pack_loading = None;
+                self.pack_post = Some((dimension, None));
+            }
         }
     }
     /// The pack `load_shader_pack` builds, once its thread is done: it runs from now on, as
@@ -6786,7 +6924,7 @@ impl Renderer {
             && !std::mem::replace(&mut self.frame_kept_logged, true)
         {
             log::info!(
-                "Horizon renderer: the {:?} frame stays until the renderer is made again; a shader API 0.2 pack picked or dropped since runs on it",
+                "Horizon renderer: the {:?} frame stays until the renderer is made again; a shader pack picked or dropped since runs on it",
                 self.frame_format
             );
         }
@@ -7035,6 +7173,28 @@ impl Renderer {
             &self.lightmap_sampler,
             &self.emission_stats.view,
         );
+        self.fluid_group = terrain_group(
+            &self.device,
+            "Still fluid resources",
+            &self.terrain_layout,
+            &self.globals,
+            &self.sprite_views,
+            &self.fluid_sampler,
+            &self.lightmap_view,
+            &self.lightmap_sampler,
+            &self.emission_stats.view,
+        );
+        self.terrain_model_group = terrain_group(
+            &self.device,
+            "Native cutout model resources",
+            &self.terrain_layout,
+            &self.globals,
+            &self.sprite_views,
+            &self.terrain_model_sampler,
+            &self.lightmap_view,
+            &self.lightmap_sampler,
+            &self.emission_stats.view,
+        );
     }
     /// Block sprite layers per array on this device: a sprite's array is its layer over it, its
     /// layer in that array the rest (`block_sprites::Lookup`).
@@ -7081,6 +7241,24 @@ impl Renderer {
             planes: frustum(views.cull().view_proj(bob)),
         }
     }
+    /// A conservative view for geometry built before TAA chooses this frame's
+    /// jitter. Cover a whole rendered pixel on each side, at the configured
+    /// resolution scale/upscale, rather than borrowing the previous frame's size.
+    pub fn camera_frustum_with_jitter(
+        &self,
+        fov_degrees: f32,
+        yaw: f32,
+        pitch: f32,
+        bob: Mat4,
+        depth_far: f32,
+    ) -> Frustum {
+        let views = ViewSet::single(self.screen_view(fov_degrees, yaw, pitch, depth_far));
+        taa_frustum(
+            views.cull().view_proj(bob),
+            self.world_post
+                .taa_render_size([self.config.width, self.config.height]),
+        )
+    }
     fn screen_view(&self, fov_degrees: f32, yaw: f32, pitch: f32, far: f32) -> View {
         let aspect = self.config.width as f32 / self.config.height.max(1) as f32;
         View::screen(yaw, pitch, fov_degrees, aspect, far)
@@ -8055,7 +8233,7 @@ impl Renderer {
         let fading_over_lods = self.sections_fading_over_lods(now);
         let fade_code = move |section: &SectionGpu, key: &SectionKey| {
             if fading_over_lods {
-                section.fade(now, retiring.contains(key))
+                section.fade(retiring.contains(key))
             } else {
                 0
             }
@@ -8676,8 +8854,12 @@ impl Renderer {
             translucent_particle_quads,
             translucent_item_quads,
             oit_entity_quads,
+            fluid_quads,
             world_text_quads,
             world_text_offset_quads,
+            native_solid_quads,
+            native_cutout_quads,
+            native_cutout_mipped_quads,
         ] = self.entity_batch.update(
             entities,
             frame.additive,
@@ -8704,13 +8886,23 @@ impl Renderer {
             + translucent_particle_quads
             + translucent_item_quads
             + oit_entity_quads
+            + fluid_quads
             + world_text_quads
-            + world_text_offset_quads;
+            + world_text_offset_quads
+            + native_solid_quads
+            + native_cutout_quads
+            + native_cutout_mipped_quads;
         laps.lap("r_draw_lists");
         // Where the tail of materials the classic and the improved passes
         // both draw ends: the shadows, particles and items count back from it.
-        let base_quads =
-            world_quads - oit_entity_quads - world_text_quads - world_text_offset_quads;
+        let base_quads = world_quads
+            - oit_entity_quads
+            - fluid_quads
+            - world_text_quads
+            - world_text_offset_quads
+            - native_solid_quads
+            - native_cutout_quads
+            - native_cutout_mipped_quads;
         let native_clouds = self.native.as_ref().is_none_or(|n| n.vanilla_clouds);
         let cloud_quads = if let Some(input) = frame.clouds.as_ref().filter(|_| native_clouds) {
             let (rebuilt, uniform) =
@@ -8954,6 +9146,12 @@ impl Renderer {
                 brightness,
             );
         }
+        self.custom_sky.prepare(
+            &mut self.uploads,
+            &mut encoder,
+            jittered,
+            &self.custom_sky_draws,
+        );
         let celestial_vertices = frame.celestial.len().min(2048 * 4);
         if frame.end_sky && !frame.title {
             self.end_sky.prepare(&self.device, frame.end_sky_sprite);
@@ -9697,6 +9895,12 @@ impl Renderer {
                                 pass.set_vertex_buffer(0, self.sunrise_buffer.slice(..));
                                 pass.draw(0..sunrise_fan::VERTICES as u32, 0..1);
                             }
+                            // OptiFine custom sky layers, over the disc and sunrise and under the
+                            // sun, moon and stars.
+                            if self.custom_sky.is_drawing() {
+                                self.custom_sky.draw(&mut pass);
+                                pass.set_bind_group(0, &self.group, &[]);
+                            }
                         }
                     }
                 }
@@ -9709,6 +9913,13 @@ impl Renderer {
                     pass.set_index_buffer(self.indices.slice(..), wgpu::IndexFormat::Uint32);
                     if frame.end_sky {
                         self.end_sky.draw(&mut pass);
+                        // The End's custom sky layers go over its sky box.
+                        if self.custom_sky.is_drawing() && !pack_draws_sky && self.native.is_none()
+                        {
+                            self.custom_sky.draw(&mut pass);
+                            pass.set_pipeline(&self.celestial_pipeline);
+                            pass.set_bind_group(0, &self.entity_group, &[]);
+                        }
                     }
                     if celestial_vertices > 0 && !pack_draws_celestial {
                         // The Overworld's bodies start with the sun's quad
@@ -10123,6 +10334,50 @@ impl Renderer {
                 }
                 pass.set_bind_group(0, &self.group, &[]);
             }
+            // Native terrain models use the block sprite arrays with their own
+            // alpha/mipmap policies and ordinary opaque depth. Storage follows
+            // the existing materials without moving their indices or frame tails.
+            let mut first =
+                world_quads - native_solid_quads - native_cutout_quads - native_cutout_mipped_quads;
+            for (i, count) in [
+                native_solid_quads,
+                native_cutout_quads,
+                native_cutout_mipped_quads,
+            ]
+            .into_iter()
+            .enumerate()
+            {
+                if count > 0 {
+                    pass.set_pipeline(&self.terrain_model_pipelines[i]);
+                    pass.set_bind_group(
+                        0,
+                        if i == 1 {
+                            &self.terrain_model_group
+                        } else {
+                            &self.fluid_group
+                        },
+                        &[],
+                    );
+                    pass.set_vertex_buffer(0, self.entity_buffer.slice(..));
+                    pass.draw_indexed(0..count * 6, (first * 4) as i32, 0..1);
+                }
+                first += count;
+            }
+            pass.set_bind_group(0, &self.group, &[]);
+            // Still-fluid block entities draw as their own ordinary sorted
+            // translucent material, before terrain transparency. This material
+            // always writes depth and never joins the improved-transparency queues.
+            if fluid_quads > 0 {
+                pass.set_pipeline(&self.fluid_pipeline);
+                pass.set_bind_group(0, &self.fluid_group, &[]);
+                pass.set_vertex_buffer(0, self.entity_buffer.slice(..));
+                pass.draw_indexed(
+                    0..fluid_quads * 6,
+                    ((base_quads + oit_entity_quads) * 4) as i32,
+                    0..1,
+                );
+                pass.set_bind_group(0, &self.group, &[]);
+            }
             if crumbling_quads > 0 && !oit_on {
                 pass.set_pipeline(&self.crumbling_pipeline);
                 pass.set_bind_group(0, &self.entity_group, &[]);
@@ -10509,7 +10764,7 @@ impl Renderer {
                 pass.set_bind_group(0, &self.entity_group, &[]);
                 pass.set_index_buffer(self.indices.slice(..), wgpu::IndexFormat::Uint32);
                 pass.set_vertex_buffer(0, self.entity_buffer.slice(..));
-                let first = base_quads + oit_entity_quads;
+                let first = base_quads + oit_entity_quads + fluid_quads;
                 for (pipeline, count, offset) in [
                     (&self.world_text_pipeline, world_text_quads, first),
                     (
@@ -10903,7 +11158,10 @@ impl Renderer {
         // submission needs this one: screenshots' readbacks, the error scopes (one per
         // thread), the first frame's startup log, VSync's frame callback, a reconfigure.
         // Frame generation presents its own frames (`frame_gen.present` below).
+        // A `screenshot-sequence` frame is submitted here, so it can wait for it to
+        // finish.
         let (encoder, surface_frame, after) = if readback.is_none()
+            && frame.pack.frame_timing.is_none()
             && fg_frames.is_none()
             && hdr_readback.is_none()
             && checks.is_none()
@@ -10988,10 +11246,14 @@ impl Renderer {
                 self.screenshot = Some(request);
             } else {
                 self.screenshot_halvings = 0;
+                self.screenshot_hdr = None;
                 if let Some(hdr_buffer) = hdr_readback {
                     let hdr_path = hdr_screenshot_path(&request.path);
                     match self.write_hdr_screenshot(&hdr_path, &hdr_buffer) {
-                        Ok(()) => log::info!("Saved HDR screenshot to {}", hdr_path.display()),
+                        Ok(()) => {
+                            log::info!("Saved HDR screenshot to {}", hdr_path.display());
+                            self.screenshot_hdr = Some(hdr_path);
+                        }
                         Err(e) => log::warn!(
                             "Horizon renderer: HDR screenshot {}: {e}",
                             hdr_path.display()
@@ -12026,6 +12288,16 @@ fn shadow_casters(view_proj: Mat4, light: Vec3) -> [Frustum; 2] {
     });
     [a, b]
 }
+fn taa_frustum(view_proj: Mat4, rendered_size: [u32; 2]) -> Frustum {
+    // TAA shifts clip x/y by at most half a rendered pixel times clip w.
+    // Widen x/y before extracting the planes: this includes every such shifted
+    // view, including a posed camera, without changing the near/far planes.
+    let [x, y] = rendered_size.map(|size| 1.0 / (1.0 + 2.0 / size.max(1) as f32));
+    Frustum {
+        planes: frustum(Mat4::from_scale(Vec3::new(x, y, 1.0)) * view_proj),
+    }
+}
+
 fn frustum(m: Mat4) -> [Vec4; 6] {
     let r = |i| m.row(i);
     let planes = [
@@ -12041,6 +12313,57 @@ fn frustum(m: Mat4) -> [Vec4; 6] {
 
 #[cfg(test)]
 mod tests {
+    #[test]
+    fn taa_culling_covers_jittered_view_edges_but_still_rejects_behind_the_camera() {
+        use super::*;
+
+        let mut outside_unjittered = 0;
+        for size in [[1, 1], [320, 180], [1280, 720], [3840, 2160]] {
+            for (yaw, pitch) in [(0.0, 0.0), (73.0, -35.0), (-142.0, 79.0)] {
+                let pose = Mat4::from_translation(Vec3::new(0.03, -0.02, 0.01))
+                    * Mat4::from_scale(Vec3::new(1.1, 0.9, 1.0))
+                    * crate::camera::view_matrix(yaw, pitch);
+                let matrix = world_projection(70.0, 16.0 / 9.0, 512.0) * pose;
+                let guarded = taa_frustum(matrix, size);
+                let ordinary = Frustum {
+                    planes: frustum(matrix),
+                };
+                for x in [-1.0, 1.0] {
+                    for y in [-1.0, 1.0] {
+                        let jitter = Mat4::from_translation(Vec3::new(
+                            x / size[0] as f32,
+                            y / size[1] as f32,
+                            0.0,
+                        ));
+                        let inverse = (jitter * matrix).inverse();
+                        for clip_x in [-1.0, 0.0, 1.0] {
+                            for clip_y in [-1.0, 0.0, 1.0] {
+                                for depth in [0.001, 0.5, 0.999] {
+                                    // Independent oracle: a point on an actual jittered
+                                    // viewport edge, transformed back into world space.
+                                    let point = inverse * Vec4::new(clip_x, clip_y, depth, 1.0);
+                                    let point = point.truncate() / point.w;
+                                    assert!(guarded.intersects_sphere(point, 1.0e-4));
+                                    let slack = Vec3::splat(1.0e-4);
+                                    assert!(guarded.intersects(point - slack, point + slack));
+                                    if !ordinary.intersects_sphere(point, 0.0) {
+                                        outside_unjittered += 1;
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+                let behind = pose.inverse().transform_point3(Vec3::new(0.0, 0.0, 10.0));
+                assert!(!guarded.intersects_sphere(behind, 0.3));
+            }
+        }
+        assert!(
+            outside_unjittered > 0,
+            "the test must need the jitter guard"
+        );
+    }
+
     #[test]
     fn depth_culling_keeps_jittered_edges_and_depth_crossing_models() {
         use super::*;
@@ -12424,8 +12747,14 @@ mod tests {
     fn the_frame_is_16_bit_only_with_hdr_and_a_device_that_draws_it() {
         use super::frame_format;
         use wgpu::TextureFormat::{Bgra8Unorm, Bgra8UnormSrgb, Rgba8Unorm, Rgba16Unorm};
-        // No 0.2 pack (or a device without the float frame) leaves it as before.
-        for linear in [(false, false), (false, true), (true, false)] {
+        // No float frame asked for (or a device without it) leaves it as before.
+        for linear in [
+            (false, false, false),
+            (false, false, true),
+            (true, false, false),
+            (false, true, false),
+            (true, true, false),
+        ] {
             assert_eq!(
                 frame_format(true, true, true, Bgra8Unorm, linear),
                 Rgba16Unorm
@@ -12455,11 +12784,41 @@ mod tests {
         use wgpu::TextureFormat::Bgra8UnormSrgb;
         for (wide_frame, hdr_offered, draws) in [(true, true, true), (false, false, false)] {
             assert_eq!(
-                frame_format(wide_frame, hdr_offered, draws, Bgra8UnormSrgb, (true, true)),
+                frame_format(
+                    wide_frame,
+                    hdr_offered,
+                    draws,
+                    Bgra8UnormSrgb,
+                    (true, false, true)
+                ),
                 LINEAR_FRAME
             );
         }
     }
+    /// HDR on without a pack under `HORIZON_HDR_FRAME=float` gets the float frame where the
+    /// surface offers HDR output, Smooth Gradients or not; where it doesn't, the frame is as
+    /// without the switch.
+    #[test]
+    fn hdr_without_a_pack_gets_the_float_frame_where_hdr_output_is_offered() {
+        use super::{LINEAR_FRAME, frame_format};
+        use wgpu::TextureFormat::{Bgra8Unorm, Bgra8UnormSrgb};
+        for (wide_frame, draws) in [(true, true), (false, false)] {
+            assert_eq!(
+                frame_format(wide_frame, true, draws, Bgra8UnormSrgb, (false, true, true)),
+                LINEAR_FRAME
+            );
+            assert_eq!(
+                frame_format(
+                    wide_frame,
+                    false,
+                    draws,
+                    Bgra8UnormSrgb,
+                    (false, true, true)
+                ),
+                Bgra8Unorm
+            );
+        }
+    }
     /// What `draws_wide_frame` needs of a device: both features, and the usages and flags
     /// every pass takes of the frame. Missing any one of them keeps the 8-bit frame.
     #[test]
@@ -12533,7 +12892,7 @@ mod tests {
         let mut batch = super::EntityBatch::default();
         let counts = batch.update(&entities, &quad(3, 5), &quad(0, 6), &quad(0, 8), false);
         let vertices = &batch.combined;
-        assert_eq!(counts, [4, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0]);
+        assert_eq!(counts, [4, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0]);
         assert_eq!(
             vertices
                 .as_chunks::<4>()
@@ -13292,7 +13651,8 @@ mod tests {
             last = now;
         }
         assert!(set_by.iter().all(|&n| n > 20), "flags set {set_by:?}");
-        assert!(handed_back > 2_000, "{handed_back} handed back");
+        // Over a thousand: the half of the uploads over far terrain come in whole.
+        assert!(handed_back > 1_000, "{handed_back} handed back");
         // Switched off with sections still flagged: none keeps a record or a
         // flag, and each is marked as while GPU culling is off.
         assert!(sim.records.fading() > 0, "none flagged at the end");
@@ -14212,8 +14572,12 @@ mod shadow_caster_tests {
 
 /// A `shaders/` pack building on its own thread (`Renderer::load_shader_pack`): the dimension it
 /// is for, the thread (a panic in it contained), and what the game named it with and when.
+/// Dropping it (another pack, none, or another dimension) cancels the build: the thread stops at
+/// the next program instead of compiling the rest for nothing.
 struct PackLoading {
     dimension: i32,
+    /// Held to be dropped with it: that cancels the build.
+    _cancel: CancelOnDrop,
     #[allow(clippy::type_complexity)]
     thread: std::thread::JoinHandle<
         std::result::Result<std::result::Result<pack_post::PackPost, pack_post::Refused>, String>,
@@ -14221,3 +14585,12 @@ struct PackLoading {
     label: String,
     started: std::time::Instant,
 }
+
+/// Sets its flag when dropped: `PackLoading`'s cancel, which `PackPost::new` checks per program.
+struct CancelOnDrop(std::sync::Arc<std::sync::atomic::AtomicBool>);
+
+impl Drop for CancelOnDrop {
+    fn drop(&mut self) {
+        self.0.store(true, std::sync::atomic::Ordering::Relaxed);
+    }
+}

crates/horizon-client-render/src/gfx/capture.rs

@@ -199,6 +199,8 @@ pub struct FrameInputs {
     pub skybox: bool,
     pub end_sky: bool,
     pub end_sky_sprite: Option<[f32; 4]>,
+    #[serde(default)]
+    pub boss_world_fog: bool,
     pub environment_fog: Option<(f32, f32)>,
     pub water_fog: [f32; 3],
     pub fog: Option<FogData>,
@@ -414,6 +416,7 @@ impl Renderer {
                 skybox: frame.skybox,
                 end_sky: frame.end_sky,
                 end_sky_sprite: frame.end_sky_sprite,
+                boss_world_fog: frame.boss_world_fog,
                 environment_fog: frame.environment_fog,
                 water_fog: frame.water_fog,
                 fog: frame.fog,
@@ -510,6 +513,7 @@ impl Scene {
             skybox: f.skybox,
             end_sky: f.end_sky,
             end_sky_sprite: f.end_sky_sprite,
+            boss_world_fog: f.boss_world_fog,
             environment_fog: f.environment_fog,
             water_fog: f.water_fog,
             fog: f.fog,

crates/horizon-client-render/src/gfx/custom_sky.rs

@@ -0,0 +1,416 @@
+//! OptiFine custom sky layers on the GPU: one texture per layer, kept with the renderer (its pack),
+//! a static skybox mesh of the 3x2 grid's six faces, and one pipeline per blend mode. A frame
+//! uploads one small uniform per drawn layer ([`crate::custom_sky::Draw`]) and draws 36 vertices
+//! each, after the vanilla sky's disc and sunrise and before the sun, moon and stars.
+use glam::Mat4;
+use horizon_optifine::sky::{Blend, Face};
+use wgpu::util::DeviceExt;
+
+use crate::custom_sky::{CustomSky as Pack, Draw};
+
+/// The blend modes in the shader's `mode` order (custom_sky.wgsl).
+const MODES: [Blend; 9] = [
+    Blend::Add,
+    Blend::Subtract,
+    Blend::Multiply,
+    Blend::Dodge,
+    Blend::Burn,
+    Blend::Screen,
+    Blend::Replace,
+    Blend::Overlay,
+    Blend::Alpha,
+];
+
+/// Layers drawn in a frame at most; a pack's later ones wait for a frame with fewer.
+const MAX_DRAWS: usize = 32;
+/// Dynamic uniform offsets are 256-byte aligned on every backend.
+const STRIDE: u64 = 256;
+
+#[repr(C)]
+#[derive(Clone, Copy, bytemuck::Pod, bytemuck::Zeroable)]
+struct Uniform {
+    clip_from_sky: [[f32; 4]; 4],
+    brightness: f32,
+    mode: u32,
+    pad: [u32; 2],
+}
+
+#[repr(C)]
+#[derive(Clone, Copy, bytemuck::Pod, bytemuck::Zeroable)]
+struct Vertex {
+    position: [f32; 3],
+    uv: [f32; 2],
+    cell: [f32; 4],
+}
+
+pub(super) struct CustomSky {
+    pipelines: Vec<wgpu::RenderPipeline>,
+    layout: wgpu::BindGroupLayout,
+    sampler: wgpu::Sampler,
+    uniform: wgpu::Buffer,
+    vertices: wgpu::Buffer,
+    /// One bind group per layer texture of the pack.
+    groups: Vec<wgpu::BindGroup>,
+    /// This frame's layers: bind group and pipeline indices.
+    frame: Vec<(u16, u8)>,
+}
+
+/// The fragment's output for each mode is in custom_sky.wgsl; these factors finish it.
+fn blend(mode: Blend) -> wgpu::BlendComponent {
+    use wgpu::BlendFactor as F;
+    let (src_factor, dst_factor, operation) = match mode {
+        Blend::Add => (F::One, F::One, wgpu::BlendOperation::Add),
+        Blend::Subtract => (F::One, F::One, wgpu::BlendOperation::ReverseSubtract),
+        Blend::Multiply => (F::Zero, F::Src, wgpu::BlendOperation::Add),
+        // dst + dst * src: lightens.
+        Blend::Dodge => (F::Dst, F::One, wgpu::BlendOperation::Add),
+        // dst * (1 - src): darkens.
+        Blend::Burn => (F::Zero, F::OneMinusSrc, wgpu::BlendOperation::Add),
+        // src + dst * (1 - src) = 1 - (1 - src)(1 - dst).
+        Blend::Screen => (F::One, F::OneMinusSrc, wgpu::BlendOperation::Add),
+        Blend::Replace => (F::One, F::Zero, wgpu::BlendOperation::Add),
+        // dst * src + src * dst.
+        Blend::Overlay => (F::Dst, F::Src, wgpu::BlendOperation::Add),
+        Blend::Alpha => (F::SrcAlpha, F::OneMinusSrcAlpha, wgpu::BlendOperation::Add),
+    };
+    wgpu::BlendComponent {
+        src_factor,
+        dst_factor,
+        operation,
+    }
+}
+
+/// The skybox's 36 vertices: two triangles per face, each corner with its cell's UV.
+fn mesh() -> Vec<Vertex> {
+    let mut out = Vec::with_capacity(36);
+    for face in Face::ALL {
+        let cell = face.cell();
+        let [u0, v0, u1, v1] = cell;
+        let uv = [[u0, v0], [u1, v0], [u1, v1], [u0, v1]];
+        let corners = face.corners();
+        for i in [0, 1, 2, 0, 2, 3] {
+            out.push(Vertex {
+                position: corners[i],
+                uv: uv[i],
+                cell,
+            });
+        }
+    }
+    out
+}
+
+impl CustomSky {
+    pub(super) fn new(device: &wgpu::Device, format: wgpu::TextureFormat) -> Self {
+        let layout = device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
+            label: Some("Custom sky bindings"),
+            entries: &[
+                wgpu::BindGroupLayoutEntry {
+                    binding: 0,
+                    visibility: wgpu::ShaderStages::VERTEX_FRAGMENT,
+                    ty: wgpu::BindingType::Buffer {
+                        ty: wgpu::BufferBindingType::Uniform,
+                        has_dynamic_offset: true,
+                        min_binding_size: wgpu::BufferSize::new(
+                            std::mem::size_of::<Uniform>() as u64
+                        ),
+                    },
+                    count: None,
+                },
+                wgpu::BindGroupLayoutEntry {
+                    binding: 1,
+                    visibility: wgpu::ShaderStages::FRAGMENT,
+                    ty: wgpu::BindingType::Texture {
+                        sample_type: wgpu::TextureSampleType::Float { filterable: true },
+                        view_dimension: wgpu::TextureViewDimension::D2,
+                        multisampled: false,
+                    },
+                    count: None,
+                },
+                wgpu::BindGroupLayoutEntry {
+                    binding: 2,
+                    visibility: wgpu::ShaderStages::FRAGMENT,
+                    ty: wgpu::BindingType::Sampler(wgpu::SamplerBindingType::Filtering),
+                    count: None,
+                },
+            ],
+        });
+        let shader = device.create_shader_module(wgpu::ShaderModuleDescriptor {
+            label: Some("Custom sky shader"),
+            source: wgpu::ShaderSource::Wgsl(include_str!("custom_sky.wgsl").into()),
+        });
+        let pipeline_layout = device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
+            label: Some("Custom sky layout"),
+            bind_group_layouts: &[Some(&layout)],
+            ..Default::default()
+        });
+        let attributes = wgpu::vertex_attr_array![0 => Float32x3, 1 => Float32x2, 2 => Float32x4];
+        let pipelines = MODES
+            .iter()
+            .map(|&mode| {
+                device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
+                    label: Some("Custom sky layer"),
+                    layout: Some(&pipeline_layout),
+                    vertex: wgpu::VertexState {
+                        module: &shader,
+                        entry_point: Some("vs_custom_sky"),
+                        compilation_options: Default::default(),
+                        buffers: &[Some(wgpu::VertexBufferLayout {
+                            array_stride: std::mem::size_of::<Vertex>() as u64,
+                            step_mode: wgpu::VertexStepMode::Vertex,
+                            attributes: &attributes,
+                        })],
+                    },
+                    primitive: wgpu::PrimitiveState {
+                        cull_mode: None,
+                        ..Default::default()
+                    },
+                    depth_stencil: Some(wgpu::DepthStencilState {
+                        format: wgpu::TextureFormat::Depth32Float,
+                        depth_write_enabled: Some(false),
+                        depth_compare: Some(wgpu::CompareFunction::Always),
+                        stencil: Default::default(),
+                        bias: Default::default(),
+                    }),
+                    multisample: Default::default(),
+                    fragment: Some(wgpu::FragmentState {
+                        module: &shader,
+                        entry_point: Some("fs_custom_sky"),
+                        compilation_options: Default::default(),
+                        targets: &[Some(wgpu::ColorTargetState {
+                            format,
+                            // The frame's alpha is HDR output's mark (hdr.wgsl): the sky
+                            // under the layers keeps its own.
+                            blend: Some(wgpu::BlendState {
+                                color: blend(mode),
+                                alpha: wgpu::BlendComponent {
+                                    src_factor: wgpu::BlendFactor::Zero,
+                                    dst_factor: wgpu::BlendFactor::One,
+                                    operation: wgpu::BlendOperation::Add,
+                                },
+                            }),
+                            write_mask: wgpu::ColorWrites::ALL,
+                        })],
+                    }),
+                    multiview_mask: None,
+                    cache: None,
+                })
+            })
+            .collect();
+        let sampler = device.create_sampler(&wgpu::SamplerDescriptor {
+            label: Some("Custom sky"),
+            min_filter: wgpu::FilterMode::Linear,
+            mag_filter: wgpu::FilterMode::Linear,
+            ..Default::default()
+        });
+        let uniform = device.create_buffer(&wgpu::BufferDescriptor {
+            label: Some("Custom sky layers"),
+            size: STRIDE * MAX_DRAWS as u64,
+            usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
+            mapped_at_creation: false,
+        });
+        let vertices = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
+            label: Some("Custom sky box"),
+            contents: bytemuck::cast_slice(&mesh()),
+            usage: wgpu::BufferUsages::VERTEX,
+        });
+        Self {
+            pipelines,
+            layout,
+            sampler,
+            uniform,
+            vertices,
+            groups: Vec::new(),
+            frame: Vec::new(),
+        }
+    }
+
+    /// The pack's layer textures, replacing any before.
+    pub(super) fn set_pack(&mut self, device: &wgpu::Device, queue: &wgpu::Queue, pack: &Pack) {
+        let limit = device.limits().max_texture_dimension_2d;
+        self.groups = pack
+            .images
+            .iter()
+            .map(|image| {
+                // Too large for this GPU: a 1x1 transparent texel, so the layer draws nothing.
+                let (width, height, rgba) = if image.width <= limit && image.height <= limit {
+                    (image.width, image.height, &image.rgba[..])
+                } else {
+                    log::warn!(
+                        "custom sky texture of {}x{} too large",
+                        image.width,
+                        image.height
+                    );
+                    (1, 1, &[0u8; 4][..])
+                };
+                let texture = device.create_texture_with_data(
+                    queue,
+                    &wgpu::TextureDescriptor {
+                        label: Some("Custom sky layer"),
+                        size: wgpu::Extent3d {
+                            width,
+                            height,
+                            depth_or_array_layers: 1,
+                        },
+                        mip_level_count: 1,
+                        sample_count: 1,
+                        dimension: wgpu::TextureDimension::D2,
+                        format: wgpu::TextureFormat::Rgba8Unorm,
+                        usage: wgpu::TextureUsages::TEXTURE_BINDING | wgpu::TextureUsages::COPY_DST,
+                        view_formats: &[],
+                    },
+                    wgpu::util::TextureDataOrder::LayerMajor,
+                    rgba,
+                );
+                let view = texture.create_view(&Default::default());
+                device.create_bind_group(&wgpu::BindGroupDescriptor {
+                    label: Some("Custom sky layer"),
+                    layout: &self.layout,
+                    entries: &[
+                        wgpu::BindGroupEntry {
+                            binding: 0,
+                            resource: wgpu::BindingResource::Buffer(wgpu::BufferBinding {
+                                buffer: &self.uniform,
+                                offset: 0,
+                                size: wgpu::BufferSize::new(std::mem::size_of::<Uniform>() as u64),
+                            }),
+                        },
+                        wgpu::BindGroupEntry {
+                            binding: 1,
+                            resource: wgpu::BindingResource::TextureView(&view),
+                        },
+                        wgpu::BindGroupEntry {
+                            binding: 2,
+                            resource: wgpu::BindingResource::Sampler(&self.sampler),
+                        },
+                    ],
+                })
+            })
+            .collect();
+    }
+
+    /// Upload this frame's layers; `clip` is clip space from camera-relative world.
+    pub(super) fn prepare(
+        &mut self,
+        uploads: &mut super::upload::Uploads,
+        encoder: &mut wgpu::CommandEncoder,
+        clip: Mat4,
+        draws: &[Draw],
+    ) {
+        self.frame.clear();
+        for draw in draws.iter().take(MAX_DRAWS) {
+            if usize::from(draw.image) >= self.groups.len() {
+                continue;
+            }
+            let mode = MODES.iter().position(|m| *m == draw.blend).unwrap_or(0);
+            let uniform = Uniform {
+                clip_from_sky: (clip * draw.rotation).to_cols_array_2d(),
+                brightness: draw.brightness.clamp(0.0, 1.0),
+                mode: mode as u32,
+                pad: [0; 2],
+            };
+            let offset = STRIDE * self.frame.len() as u64;
+            uploads.buffer(encoder, &self.uniform, offset, bytemuck::bytes_of(&uniform));
+            self.frame.push((draw.image, mode as u8));
+        }
+    }
+
+    pub(super) fn is_drawing(&self) -> bool {
+        !self.frame.is_empty()
+    }
+
+    /// The layers [`CustomSky::prepare`] uploaded. Leaves the pass's pipeline and bind group 0
+    /// changed.
+    pub(super) fn draw(&self, pass: &mut wgpu::RenderPass<'_>) {
+        pass.set_vertex_buffer(0, self.vertices.slice(..));
+        for (i, &(image, mode)) in self.frame.iter().enumerate() {
+            pass.set_pipeline(&self.pipelines[usize::from(mode)]);
+            pass.set_bind_group(
+                0,
+                &self.groups[usize::from(image)],
+                &[(STRIDE * i as u64) as u32],
+            );
+            pass.draw(0..36, 0..1);
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// What a blend leaves a sky texel of `dst` with when the shader outputs `src`
+    /// (custom_sky.wgsl) for a layer texel `t` at brightness `b`, per channel.
+    fn mix(mode: Blend, dst: f32, t: f32, a: f32, b: f32) -> f32 {
+        let k = a * b;
+        let src = match mode {
+            Blend::Multiply => 1.0 + (t - 1.0) * k,
+            Blend::Overlay => 0.5 + (t - 0.5) * k,
+            Blend::Replace | Blend::Alpha => t,
+            _ => t * k,
+        };
+        let c = blend(mode);
+        let f = |factor: wgpu::BlendFactor| match factor {
+            wgpu::BlendFactor::One => 1.0,
+            wgpu::BlendFactor::Zero => 0.0,
+            wgpu::BlendFactor::Src => src,
+            wgpu::BlendFactor::OneMinusSrc => 1.0 - src,
+            wgpu::BlendFactor::Dst => dst,
+            wgpu::BlendFactor::SrcAlpha => k,
+            wgpu::BlendFactor::OneMinusSrcAlpha => 1.0 - k,
+            other => panic!("{other:?}"),
+        };
+        let (s, d) = (src * f(c.src_factor), dst * f(c.dst_factor));
+        match c.operation {
+            wgpu::BlendOperation::Add => s + d,
+            wgpu::BlendOperation::ReverseSubtract => d - s,
+            other => panic!("{other:?}"),
+        }
+    }
+
+    #[test]
+    fn every_mode_gives_its_documented_result() {
+        let close = |a: f32, b: f32| assert!((a - b).abs() < 1e-6, "{a} != {b}");
+        // Full brightness and alpha, a sky texel of 0.4 under a layer texel of 0.8.
+        let (d, t) = (0.4, 0.8);
+        close(mix(Blend::Add, d, t, 1.0, 1.0), 1.2);
+        close(mix(Blend::Subtract, d, t, 1.0, 1.0), -0.4);
+        close(mix(Blend::Multiply, d, t, 1.0, 1.0), 0.32);
+        close(mix(Blend::Screen, d, t, 1.0, 1.0), 1.0 - 0.6 * 0.2);
+        close(mix(Blend::Replace, d, t, 1.0, 1.0), 0.8);
+        close(mix(Blend::Overlay, d, t, 1.0, 1.0), 0.64);
+        close(mix(Blend::Overlay, d, 0.2, 1.0, 1.0), 0.16);
+        close(mix(Blend::Alpha, d, t, 0.25, 1.0), 0.4 * 0.75 + 0.8 * 0.25);
+        assert!(mix(Blend::Dodge, d, t, 1.0, 1.0) > d);
+        assert!(mix(Blend::Burn, d, t, 1.0, 1.0) < d);
+        // Faded out, every mode but replace (drawn only when bright) leaves the sky alone.
+        for mode in MODES {
+            if mode != Blend::Replace {
+                close(mix(mode, d, t, 1.0, 0.0), d);
+            }
+        }
+        // Half faded: add adds half.
+        close(mix(Blend::Add, d, t, 1.0, 0.5), 0.8);
+    }
+
+    #[test]
+    fn the_shader_validates() {
+        let module = naga::front::wgsl::parse_str(include_str!("custom_sky.wgsl")).unwrap();
+        naga::valid::Validator::new(
+            naga::valid::ValidationFlags::all(),
+            naga::valid::Capabilities::all(),
+        )
+        .validate(&module)
+        .unwrap();
+    }
+
+    #[test]
+    fn the_box_covers_every_face_with_its_cell() {
+        let mesh = mesh();
+        assert_eq!(mesh.len(), 36);
+        for v in &mesh {
+            let [u0, v0, u1, v1] = v.cell;
+            assert!((u0..=u1).contains(&v.uv[0]) && (v0..=v1).contains(&v.uv[1]));
+            assert_eq!(v.position.iter().filter(|c| c.abs() == 1.0).count(), 3);
+        }
+    }
+}

crates/horizon-client-render/src/gfx/custom_sky.wgsl

@@ -0,0 +1,61 @@
+// OptiFine custom sky layers (gfx/custom_sky.rs): one skybox per draw, its six faces cut from a
+// 3x2 texture, mixed with the sky under it by the pipeline's blend. The fragment's output is
+// chosen so that blend gives the layer's documented mode at its brightness, and a layer at
+// brightness 0 leaves the sky as it was.
+struct Layer {
+    // Projection * view (camera-relative) * the layer's rotation.
+    clip_from_sky: mat4x4<f32>,
+    brightness: f32,
+    // horizon_optifine::sky::Blend, in gfx/custom_sky.rs's MODES order.
+    mode: u32,
+}
+@group(0) @binding(0) var<uniform> layer: Layer;
+@group(0) @binding(1) var sky_texture: texture_2d<f32>;
+@group(0) @binding(2) var sky_sampler: sampler;
+
+struct Out {
+    @builtin(position) clip: vec4<f32>,
+    @location(0) uv: vec2<f32>,
+    // The face's cell (u0, v0, u1, v1): sampling stays half a texel inside it.
+    @location(1) @interpolate(flat) cell: vec4<f32>,
+}
+
+@vertex fn vs_custom_sky(
+    @location(0) position: vec3<f32>,
+    @location(1) uv: vec2<f32>,
+    @location(2) cell: vec4<f32>,
+) -> Out {
+    var out: Out;
+    out.clip = layer.clip_from_sky * vec4(position * 100.0, 1.0);
+    out.uv = uv;
+    out.cell = cell;
+    return out;
+}
+
+const ADD: u32 = 0u;
+const SUBTRACT: u32 = 1u;
+const MULTIPLY: u32 = 2u;
+const DODGE: u32 = 3u;
+const BURN: u32 = 4u;
+const SCREEN: u32 = 5u;
+const REPLACE: u32 = 6u;
+const OVERLAY: u32 = 7u;
+const ALPHA: u32 = 8u;
+
+@fragment fn fs_custom_sky(in: Out) -> @location(0) vec4<f32> {
+    let half = 0.5 / vec2<f32>(textureDimensions(sky_texture));
+    let uv = clamp(in.uv, in.cell.xy + half, in.cell.zw - half);
+    let t = textureSample(sky_texture, sky_sampler, uv);
+    let k = t.a * layer.brightness;
+    switch layer.mode {
+        // dst * src: white leaves the sky alone.
+        case MULTIPLY: { return vec4(mix(vec3(1.0), t.rgb, k), 1.0); }
+        // 2 * dst * src: grey leaves it alone.
+        case OVERLAY: { return vec4(mix(vec3(0.5), t.rgb, k), 1.0); }
+        case REPLACE: { return vec4(t.rgb, 1.0); }
+        // mix(dst, src, alpha).
+        case ALPHA: { return vec4(t.rgb, k); }
+        // add, subtract, dodge, burn, screen: the layer premultiplied, black leaves it alone.
+        default: { return vec4(t.rgb * k, 1.0); }
+    }
+}

crates/horizon-client-render/src/gfx/entity_batch.rs

@@ -14,8 +14,24 @@ use super::Vertex;
 /// material at the end: the render types vanilla gives an `OitPipelineSet`
 /// (translucent, emissive, eyes and breeze wind entity models). Off, the tag is
 /// ignored and they stay in the first one, in their order.
-/// Two native world-canvas text materials follow it, NORMAL then POLYGON_OFFSET.
-const MATERIALS: usize = 12;
+/// Sorted still-fluid geometry follows, then the two native world-canvas text materials,
+/// NORMAL and POLYGON_OFFSET. Material storage order is independent of their draw stages.
+const MATERIALS: usize = 16;
+pub const TERRAIN_MODEL_SOLID_OVERLAY: u32 = 42;
+pub const TERRAIN_MODEL_CUTOUT_OVERLAY: u32 = 43;
+pub const TERRAIN_MODEL_CUTOUT_MIPPED_OVERLAY: u32 = 44;
+/// Native terrain-array UV/payloads must never enter a shared-atlas shader-pack pass.
+pub fn is_native_terrain(layer: u32) -> bool {
+    matches!(
+        layer & 0xffff,
+        FLUID_OVERLAY
+            | TERRAIN_MODEL_SOLID_OVERLAY
+            | TERRAIN_MODEL_CUTOUT_OVERLAY
+            | TERRAIN_MODEL_CUTOUT_MIPPED_OVERLAY
+    )
+}
+/// Sorted depth-writing still fluid, sampling terrain sprite arrays rather than the shared atlas.
+pub const FLUID_OVERLAY: u32 = 41;
 /// A bit of `Vertex::layer`, above the overlay (low 16 bits) and the HDR tier
 /// (bits 16 to 23): the quad's render type has an `OitPipelineSet`
 /// (`RenderTypes.entityTranslucent`, `entityTranslucentEmissive`, `eyes`,
@@ -31,7 +47,9 @@ pub const DISSOLVE_OVERLAY: u32 = 38;
 /// (`OIT_ENTITY`): improved transparency draws them in its stages.
 pub fn mark_oit(quads: &mut [Vertex]) {
     for vertex in quads {
-        vertex.layer |= OIT_ENTITY;
+        if !is_native_terrain(vertex.layer) {
+            vertex.layer |= OIT_ENTITY;
+        }
     }
 }
 /// The overlay of depth-only quads that hide water (`RenderTypes.waterMask`).
@@ -60,12 +78,21 @@ pub const WORLD_TEXT_POLYGON_OFFSET_OVERLAY: u32 = 40;
 /// The material of a quad by its overlay (`MATERIALS` order): the overlay is the layer's low 16
 /// bits, as entity.wgsl reads it; HDR output's tier rides in the high ones.
 fn material(layer: u32, oit: bool) -> usize {
+    match layer & 0xffff {
+        TERRAIN_MODEL_SOLID_OVERLAY => return 13,
+        TERRAIN_MODEL_CUTOUT_OVERLAY => return 14,
+        TERRAIN_MODEL_CUTOUT_MIPPED_OVERLAY => return 15,
+        _ => {}
+    }
+    if layer & 0xffff == FLUID_OVERLAY {
+        return 10;
+    }
     if oit && layer & OIT_ENTITY != 0 {
         return 9;
     }
     match layer & 0xffff {
-        WORLD_TEXT_OVERLAY => 10,
-        WORLD_TEXT_POLYGON_OFFSET_OVERLAY => 11,
+        WORLD_TEXT_OVERLAY => 11,
+        WORLD_TEXT_POLYGON_OFFSET_OVERLAY => 12,
         TEXT_POLYGON_OFFSET_OVERLAY => 1,
         11 => 2,
         12 => 3,
@@ -148,10 +175,10 @@ impl EntityBatch {
                 }
             }
         }
-        // RenderType.text sorts alpha-blended quads from far to near. Keep
-        // both world-canvas layers after existing materials (including eyes
-        // moved out of additive); front text uses polygon offset.
-        for runs in &self.runs[10..] {
+        // Fluid and RenderType.text sort their own alpha-blended quads far to
+        // near. Fluid precedes both world-canvas layers, after existing materials
+        // (including eyes moved out of additive).
+        for runs in &self.runs[10..13] {
             let start = self.combined.len();
             for &(first, count) in runs {
                 self.combined
@@ -169,6 +196,13 @@ impl EntityBatch {
                     distance(b).total_cmp(&distance(a))
                 });
         }
+        // Native solid/cutout models are depth writing and keep their submission order.
+        for runs in &self.runs[13..] {
+            for &(first, count) in runs {
+                self.combined
+                    .extend_from_slice(&entities[first * 4..(first + count) * 4]);
+            }
+        }
         if self.moved_additive == 0 {
             self.combined.extend_from_slice(additive);
         } else {
@@ -189,7 +223,57 @@ mod tests {
     use super::*;
     use std::{hint::black_box, time::Instant};
     #[test]
-    fn world_canvas_sorts_after_oit_eyes_before_frame_tails() {
+    fn native_models_keep_opaque_order_and_do_not_move_existing_materials_or_tails() {
+        let quad = |layer, x| {
+            [Vertex {
+                layer,
+                pos: [x, 0.0, 0.0],
+                ..geometry(1, false)[0]
+            }; 4]
+        };
+        let entities: Vec<_> = [
+            (FLUID_OVERLAY, 10.0),
+            (WORLD_TEXT_OVERLAY, 11.0),
+            (TERRAIN_MODEL_SOLID_OVERLAY | 279 << 16, 3.0),
+            (TERRAIN_MODEL_SOLID_OVERLAY, 1.0),
+            (TERRAIN_MODEL_CUTOUT_OVERLAY, 4.0),
+            (TERRAIN_MODEL_CUTOUT_MIPPED_OVERLAY, 5.0),
+            (OIT_ENTITY, 6.0),
+            (0, 7.0),
+        ]
+        .into_iter()
+        .flat_map(|(layer, x)| quad(layer, x))
+        .collect();
+        let mut batch = EntityBatch::default();
+        let counts = batch.update(
+            &entities,
+            &quad(0, 8.0),
+            &quad(0, 9.0),
+            &quad(0, 12.0),
+            true,
+        );
+        assert_eq!(counts, [1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 2, 1, 1]);
+        let xs: Vec<_> = batch.combined.iter().step_by(4).map(|v| v.pos[0]).collect();
+        assert_eq!(
+            xs,
+            [7.0, 6.0, 10.0, 11.0, 3.0, 1.0, 4.0, 5.0, 8.0, 9.0, 12.0]
+        );
+        assert_eq!(
+            batch.combined[16].layer,
+            TERRAIN_MODEL_SOLID_OVERLAY | 279 << 16
+        );
+    }
+    #[test]
+    fn tagging_oit_does_not_corrupt_a_native_models_sprite_index() {
+        let mut vertices = [geometry(1, false)[0]; 2];
+        vertices[0].layer = TERRAIN_MODEL_CUTOUT_OVERLAY | 17 << 16;
+        vertices[1].layer = 3;
+        mark_oit(&mut vertices);
+        assert_eq!(vertices[0].layer, TERRAIN_MODEL_CUTOUT_OVERLAY | 17 << 16);
+        assert_eq!(vertices[1].layer, 3 | OIT_ENTITY);
+    }
+    #[test]
+    fn fluid_and_world_canvas_sort_after_oit_eyes_before_frame_tails() {
         let quad = |layer, x| {
             [Vertex {
                 layer,
@@ -204,6 +288,8 @@ mod tests {
             (WORLD_TEXT_OVERLAY, 4.0),
             (WORLD_TEXT_OVERLAY, 5.0),
             (WORLD_TEXT_POLYGON_OFFSET_OVERLAY, 6.0),
+            (FLUID_OVERLAY, 11.0),
+            (FLUID_OVERLAY | OIT_ENTITY, 12.0),
         ]
         .into_iter()
         .flat_map(|(layer, x)| quad(layer, x))
@@ -215,12 +301,14 @@ mod tests {
         let mut batch = EntityBatch::default();
         assert_eq!(
             batch.update(&entities, &additive, &quad(0, 9.0), &quad(0, 10.0), true),
-            [1, 1, 0, 0, 0, 0, 0, 0, 0, 2, 2, 1]
+            [1, 1, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 1, 0, 0, 0]
         );
         let positions: Vec<_> = batch.combined.iter().step_by(4).map(|v| v.pos[0]).collect();
         assert_eq!(
             positions,
-            [1.0, 2.0, 3.0, 7.0, 5.0, 4.0, 6.0, 8.0, 9.0, 10.0]
+            [
+                1.0, 2.0, 3.0, 7.0, 12.0, 11.0, 5.0, 4.0, 6.0, 8.0, 9.0, 10.0
+            ]
         );
     }
 
@@ -320,12 +408,12 @@ mod tests {
         let mut batch = EntityBatch::default();
         // Off: the tag changes nothing, the quads keep their place.
         let counts = batch.update(&entities, &[], &[], &[], false);
-        assert_eq!(counts, [4, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0]);
+        assert_eq!(counts, [4, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0]);
         let xs: Vec<f32> = batch.combined.iter().step_by(4).map(|v| v.pos[0]).collect();
         assert_eq!(xs, [0.0, 1.0, 2.0, 4.0, 3.0]);
         // On: the tagged quads come last, in order.
         let counts = batch.update(&entities, &[], &[], &[], true);
-        assert_eq!(counts, [2, 0, 0, 0, 0, 0, 1, 0, 0, 2, 0, 0]);
+        assert_eq!(counts, [2, 0, 0, 0, 0, 0, 1, 0, 0, 2, 0, 0, 0, 0, 0, 0]);
         let xs: Vec<f32> = batch.combined.iter().step_by(4).map(|v| v.pos[0]).collect();
         assert_eq!(xs, [0.0, 2.0, 3.0, 1.0, 4.0]);
     }

crates/horizon-client-render/src/gfx/fluid.rs

@@ -0,0 +1,69 @@
+//! Sorted still-fluid material: ordinary back culling, alpha blend and color/depth writes.
+pub(super) const SAMPLER: wgpu::SamplerDescriptor<'static> = wgpu::SamplerDescriptor {
+    label: Some("Still fluid (nearest texels, linear mipmaps)"),
+    address_mode_u: wgpu::AddressMode::ClampToEdge,
+    address_mode_v: wgpu::AddressMode::ClampToEdge,
+    address_mode_w: wgpu::AddressMode::ClampToEdge,
+    mag_filter: wgpu::FilterMode::Nearest,
+    min_filter: wgpu::FilterMode::Nearest,
+    mipmap_filter: wgpu::MipmapFilterMode::Linear,
+    lod_min_clamp: 0.0,
+    lod_max_clamp: 32.0,
+    compare: None,
+    anisotropy_clamp: 1,
+    border_color: None,
+};
+
+pub(super) fn pipeline(
+    device: &wgpu::Device,
+    layout: Option<&wgpu::PipelineLayout>,
+    shader: &wgpu::ShaderModule,
+    format: wgpu::TextureFormat,
+    constants: &[(&str, f64)],
+) -> wgpu::RenderPipeline {
+    let attributes = wgpu::vertex_attr_array![0=>Float32x3,1=>Float32x2,2=>Uint32,3=>Unorm8x4,4=>Uint8x4,5=>Snorm8x4,6=>Float32x2];
+    device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
+        label: Some("Still fluid"),
+        layout,
+        vertex: wgpu::VertexState {
+            module: shader,
+            entry_point: Some("vs_native_fluid"),
+            compilation_options: wgpu::PipelineCompilationOptions {
+                constants,
+                ..Default::default()
+            },
+            buffers: &[Some(wgpu::VertexBufferLayout {
+                array_stride: std::mem::size_of::<super::Vertex>() as u64,
+                step_mode: wgpu::VertexStepMode::Vertex,
+                attributes: &attributes,
+            })],
+        },
+        primitive: wgpu::PrimitiveState {
+            cull_mode: Some(wgpu::Face::Back),
+            ..Default::default()
+        },
+        depth_stencil: Some(wgpu::DepthStencilState {
+            format: wgpu::TextureFormat::Depth32Float,
+            depth_write_enabled: Some(true),
+            depth_compare: Some(wgpu::CompareFunction::GreaterEqual),
+            stencil: Default::default(),
+            bias: Default::default(),
+        }),
+        multisample: Default::default(),
+        fragment: Some(wgpu::FragmentState {
+            module: shader,
+            entry_point: Some("fs_native_fluid"),
+            compilation_options: wgpu::PipelineCompilationOptions {
+                constants,
+                ..Default::default()
+            },
+            targets: &[Some(wgpu::ColorTargetState {
+                format,
+                blend: Some(wgpu::BlendState::ALPHA_BLENDING),
+                write_mask: wgpu::ColorWrites::ALL,
+            })],
+        }),
+        multiview_mask: None,
+        cache: None,
+    })
+}

crates/horizon-client-render/src/gfx/native_post.rs

@@ -849,6 +849,15 @@ impl NativeFrame {
         inputs
     }
 
+    /// Forgets the frames before, as a freshly loaded pack: the post stage's next `history` is
+    /// black, eased values start at their targets, wetness dry, the frame count at 0.
+    pub(super) fn reset_history(&mut self) {
+        self.last = None;
+        self.frames = 0;
+        self.wetness = (0.0, None);
+        self.start = std::time::Instant::now();
+    }
+
     /// Takes the post stage's pending history reset. It stays pending if post rendering is
     /// skipped for a frame, so the first frame it does render still sees black history.
     pub(super) fn take_history_reset(&mut self) -> bool {
@@ -1119,6 +1128,13 @@ impl NativePost {
             .collect()
     }
 
+    /// Forgets the pack's own targets (`[[post]] output`): made again, blank, on the next frame,
+    /// as for a pack just made. Its pipelines stay.
+    pub(super) fn reset_history(&mut self) {
+        self.named = None;
+        self.groups = None;
+    }
+
     fn prepare(
         &mut self,
         device: &wgpu::Device,
@@ -1737,6 +1753,152 @@ mod tests {
         assert!(!native.take_history_reset());
     }
 
+    /// After a reset, the same frames give the same inputs, to the bit, as a pack just made,
+    /// however the frames before moved the eased values, wetness and the frame count.
+    #[test]
+    fn a_reset_frame_gives_a_fresh_pack_s_inputs() {
+        use crate::gfx::pack_uniforms::FrameTiming;
+        let Some((device, _)) = device() else {
+            return;
+        };
+        let hud = crate::hud::HudBatch::new([4, 4]);
+        let mut frame = crate::gfx::pack_uniforms::initial_history_tests::frame(&hud);
+        let new = || {
+            NativeFrame::new(
+                &device,
+                None,
+                Vec::new(),
+                Default::default(),
+                None,
+                Api::V0_1,
+            )
+        };
+        let (mut used, mut fresh) = (new(), new());
+        frame.pack.rain = 1.0;
+        frame.pack.eye_light = [12, 3];
+        frame.pack.eye_in = 1;
+        for n in 1..=5 {
+            frame.pack.frame_timing = Some(FrameTiming::nth(n, 700.0));
+            used.next_inputs(&frame, [4, 4]);
+        }
+        used.reset_history();
+        frame.pack.eye_light = [2, 15];
+        frame.pack.eye_in = 0;
+        for n in 1..=3 {
+            frame.pack.frame_timing = Some(FrameTiming::nth(n, 50.0));
+            let inputs = [&mut used, &mut fresh].map(|f| f.next_inputs(&frame, [4, 4]));
+            assert_eq!(
+                bytemuck::bytes_of(&inputs[0]),
+                bytemuck::bytes_of(&inputs[1]),
+                "frame {n}"
+            );
+            assert_eq!(used.take_history_reset(), fresh.take_history_reset());
+        }
+    }
+
+    /// After a reset a pass reads its pack's own targets blank, as in a pack just made: here
+    /// `fb`, which a pass reads before the pass that writes it, so it holds last frame's.
+    #[test]
+    fn a_reset_post_reads_its_own_targets_blank() {
+        let Some((device, queue)) = device() else {
+            return;
+        };
+        let manifest = "schema = 1
+id = \"t\"
+name = \"T\"
+version = \"1\"
+api = \"0.1\"
+            [[post]]
+file = \"a.wgsl\"
+[[post]]
+file = \"b.wgsl\"
+output = \"fb\"
+            [[post]]
+file = \"c.wgsl\"
+";
+        let a = "fn post(input: PostInput) -> vec4<f32> { return vec4<f32>(textureLoad(fb, vec2<i32>(input.pixel), 0).rgb + 0.25, 1.0); }
+";
+        let pass = "fn post(input: PostInput) -> vec4<f32> { return input.color; }
+";
+        let files = [
+            (MANIFEST, manifest),
+            ("a.wgsl", a),
+            ("b.wgsl", pass),
+            ("c.wgsl", pass),
+        ]
+        .map(|(n, t)| (n.to_owned(), t.as_bytes().to_vec()))
+        .into();
+        let report = check(&Pack::from_files(files).unwrap()).unwrap();
+        let format = wgpu::TextureFormat::Rgba8Unorm;
+        let frame = NativeFrame::new(
+            &device,
+            None,
+            Vec::new(),
+            Default::default(),
+            None,
+            Api::V0_1,
+        );
+        let mut post = NativePost::new(
+            &device,
+            report.stages,
+            &report.manifest,
+            &[],
+            format,
+            &frame,
+            None,
+        )
+        .unwrap();
+        let usage = wgpu::TextureUsages::RENDER_ATTACHMENT | wgpu::TextureUsages::TEXTURE_BINDING;
+        let color = texture(&device, format, usage).create_view(&Default::default());
+        let depth = texture(&device, wgpu::TextureFormat::Depth32Float, usage)
+            .create_view(&Default::default());
+        let screen = texture(
+            &device,
+            format,
+            wgpu::TextureUsages::RENDER_ATTACHMENT | wgpu::TextureUsages::COPY_SRC,
+        );
+        let view = screen.create_view(&Default::default());
+        let buffer = device.create_buffer(&wgpu::BufferDescriptor {
+            label: None,
+            size: u64::from(wgpu::COPY_BYTES_PER_ROW_ALIGNMENT * 4),
+            usage: wgpu::BufferUsages::MAP_READ | wgpu::BufferUsages::COPY_DST,
+            mapped_at_creation: false,
+        });
+        let red = |post: &mut NativePost| {
+            let mut encoder = device.create_command_encoder(&Default::default());
+            let world = (&color, &depth, &frame.surface_view);
+            post.run(&device, &mut encoder, world, &view, [4, 4], false, None);
+            encoder.copy_texture_to_buffer(
+                screen.as_image_copy(),
+                wgpu::TexelCopyBufferInfo {
+                    buffer: &buffer,
+                    layout: wgpu::TexelCopyBufferLayout {
+                        offset: 0,
+                        bytes_per_row: Some(wgpu::COPY_BYTES_PER_ROW_ALIGNMENT),
+                        rows_per_image: Some(4),
+                    },
+                },
+                screen.size(),
+            );
+            queue.submit([encoder.finish()]);
+            buffer
+                .slice(..)
+                .map_async(wgpu::MapMode::Read, |r| r.unwrap());
+            device.poll(wgpu::PollType::wait_indefinitely()).unwrap();
+            let red = buffer.slice(..).get_mapped_range().unwrap()[0];
+            buffer.unmap();
+            red
+        };
+        let near = |got: u8, want: u8| got.abs_diff(want) <= 1;
+        for want in [64, 128, 191] {
+            let got = red(&mut post);
+            assert!(near(got, want), "{got} before the reset, {want} expected");
+        }
+        post.reset_history();
+        let got = red(&mut post);
+        assert!(near(got, 64), "{got} after the reset: fb kept last frame's");
+    }
+
     fn device() -> Option<(wgpu::Device, wgpu::Queue)> {
         let instance = crate::gfx::test_gpu::instance();
         let adapter = pollster::block_on(instance.request_adapter(&Default::default())).ok()?;

crates/horizon-client-render/src/gfx/pack_center_depth.rs

@@ -217,6 +217,41 @@ impl CenterDepth {
         })
     }
 
+    /// Once the GPU has finished the frame (`screenshot-sequence`), the depth it copied, as
+    /// the next frame reads it: an error unless exactly that one sample was read back, never
+    /// an older one.
+    pub fn take_completed(&mut self, device: &wgpu::Device) -> Result<f32, String> {
+        device
+            .poll(wgpu::PollType::Poll)
+            .map_err(|e| e.to_string())?;
+        let state = |s: &Slot| s.state.load(Ordering::Acquire);
+        let mut mapped = self.slots.iter().filter(|s| state(s) == MAPPED);
+        let (Some(slot), None) = (mapped.next(), mapped.next()) else {
+            return Err("the frame's centre depth wasn't read back alone".into());
+        };
+        if self
+            .slots
+            .iter()
+            .any(|s| !matches!(state(s), FREE | MAPPED))
+        {
+            return Err("the frame's centre depth wasn't read back alone".into());
+        }
+        let depth = slot
+            .buffer
+            .slice(..4)
+            .get_mapped_range()
+            .map(|bytes| bytemuck::pod_read_unaligned::<f32>(&bytes[..4]))
+            .map_err(|e| e.to_string());
+        slot.buffer.unmap();
+        slot.state.store(FREE, Ordering::Release);
+        let depth = depth?;
+        if !depth.is_finite() {
+            return Err("the centre depth isn't finite".into());
+        }
+        self.latest = Some(depth.clamp(0.0, 1.0));
+        Ok(depth.clamp(0.0, 1.0))
+    }
+
     /// The newest depth read back so far, `None` before the first arrives.
     pub fn collect(&mut self, device: &wgpu::Device) -> Option<f32> {
         let _ = device.poll(wgpu::PollType::Poll);
@@ -265,6 +300,76 @@ mod tests {
         });
     }
 
+    /// Inline and on the submit thread: each finished frame's depth, then none left to
+    /// take; several outstanding samples are refused.
+    #[test]
+    #[ignore = "requires a host GPU"]
+    fn a_finished_frame_s_depth_is_taken_alone_never_an_older_one() {
+        let (device, raw) = test_device().expect("host GPU required");
+        let depth = device.create_texture(&wgpu::TextureDescriptor {
+            label: None,
+            size: wgpu::Extent3d {
+                width: 3,
+                height: 3,
+                depth_or_array_layers: 1,
+            },
+            mip_level_count: 1,
+            sample_count: 1,
+            dimension: wgpu::TextureDimension::D2,
+            format: wgpu::TextureFormat::Depth32Float,
+            usage: wgpu::TextureUsages::RENDER_ATTACHMENT | wgpu::TextureUsages::TEXTURE_BINDING,
+            view_formats: &[],
+        });
+        let view = depth.create_view(&Default::default());
+        for threaded in [false, true] {
+            let queue = super::super::submit::Queue::new(raw.clone(), threaded);
+            if threaded {
+                assert!(queue.threaded(), "deferred submit unavailable");
+            }
+            let mut center = CenterDepth::new(&device);
+            assert!(center.take_completed(&device).is_err());
+            for value in [0.125, 0.75, 0.25] {
+                let mut encoder = device.create_command_encoder(&Default::default());
+                clear(&mut encoder, &view, value);
+                center.copy(&device, &mut encoder, &depth);
+                let after = center.submitted().expect("one copied sample");
+                if threaded {
+                    let job = super::super::submit::Job {
+                        encoder,
+                        surface: None,
+                        after: Some(Box::new(after)),
+                    };
+                    assert!(queue.submit_later(job).is_ok());
+                    queue.wait();
+                } else {
+                    queue.submit([encoder.finish()]);
+                    after();
+                }
+                device
+                    .poll(wgpu::PollType::Wait {
+                        submission_index: None,
+                        timeout: Some(std::time::Duration::from_secs(30)),
+                    })
+                    .unwrap();
+                assert_eq!(center.take_completed(&device).unwrap(), value);
+                assert_eq!(center.collect(&device), Some(value));
+                assert!(
+                    center.take_completed(&device).is_err(),
+                    "no stale latest fallback"
+                );
+            }
+            // Several outstanding copies are ambiguous, even after they all map.
+            let mut encoder = device.create_command_encoder(&Default::default());
+            for _ in 0..SLOTS {
+                center.copy(&device, &mut encoder, &depth);
+            }
+            queue.submit([encoder.finish()]);
+            center.submitted().unwrap()();
+            device.poll(wgpu::PollType::wait_indefinitely()).unwrap();
+            assert!(center.take_completed(&device).is_err());
+        }
+    }
+
     /// Frames that go to the submit thread start their readback there: the centre depth
     /// follows the frames instead of keeping the first ones' depth.
     #[test]

crates/horizon-client-render/src/gfx/pack_entities.rs

@@ -454,9 +454,31 @@ impl PackEntities {
         let first = spans.first().map_or(entities.len(), |s| s.start as usize);
         extend_without_portals(rest, &entities[..first.min(entities.len())]);
         let (mut other, mut portal_faces, mut beam_faces) = (Vec::new(), Vec::new(), Vec::new());
+        let mut without_fluids = Vec::new();
         for (span, range) in runs(entities.len(), spans) {
             let run_start = range.start as u32;
             let whole = &entities[range];
+            // A native fluid carries sprite-array UVs, not shared-atlas UVs.
+            // Keep it in its own material even when a shader pack draws the
+            // model in the same block-entity run. Do not corrupt either UV space.
+            let whole: &[Vertex] = if whole
+                .chunks(4)
+                .any(|q| super::is_native_terrain(q[0].layer))
+            {
+                without_fluids.clear();
+                for quad in whole.chunks(4) {
+                    if super::is_native_terrain(quad[0].layer) {
+                        if !span.hidden {
+                            rest.extend_from_slice(quad);
+                        }
+                    } else {
+                        without_fluids.extend_from_slice(quad);
+                    }
+                }
+                &without_fluids
+            } else {
+                whole
+            };
             // A block entity's run can hold End portal faces and beams beside plain parts (an End
             // gateway: its cube and its beam): each goes to its own program.
             // Beacon beams come in a run of their own, at stage NONE (game.rs: no stage of 5.4
@@ -1141,6 +1163,83 @@ fn skin_runs(skin: &super::entity_skin::SkinFrame) -> Vec<(EntitySpan, Range<u32
 mod gpu_span_tests {
     use super::*;
     use crate::gfx::entity_skin::{SkinFrame, SkinJob};
+    #[test]
+    #[ignore = "requires a Vulkan/Metal/DX12 adapter"]
+    fn native_fluid_stays_native_while_model_uses_pack() {
+        let instance = crate::gfx::test_gpu::instance();
+        let adapter = pollster::block_on(instance.request_adapter(&Default::default())).unwrap();
+        let (device, queue) =
+            pollster::block_on(adapter.request_device(&Default::default())).unwrap();
+        let layout = super::super::pack_draw::DrawUniforms::new(&device);
+        let mut geometry = PackEntities::new(&device, &layout.layout);
+        for overlay in [
+            super::super::FLUID_OVERLAY,
+            super::super::TERRAIN_MODEL_SOLID_OVERLAY,
+            super::super::TERRAIN_MODEL_CUTOUT_OVERLAY,
+            super::super::TERRAIN_MODEL_CUTOUT_MIPPED_OVERLAY,
+        ] {
+            let mut mixed = vec![
+                Vertex {
+                    layer: 0,
+                    ..bytemuck::Zeroable::zeroed()
+                };
+                8
+            ];
+            for v in &mut mixed[4..] {
+                v.layer = overlay | 279 << 16;
+                v.uv = [0.25, 0.75];
+                v.glint_uv = [17.0, 0.0];
+            }
+            let mut rest = Vec::new();
+            for hidden in [false, true] {
+                geometry.prepare(
+                    &device,
+                    &queue,
+                    &layout.layout,
+                    &mixed,
+                    &[EntitySpan {
+                        start: 0,
+                        id: 77,
+                        stage: render_stage("BLOCK_ENTITIES"),
+                        hidden,
+                        ..Default::default()
+                    }],
+                    [true; PROGRAMS],
+                    ([0.; 4], [1; 2]),
+                    Casters {
+                        blocks: true,
+                        ..Default::default()
+                    },
+                    &mut rest,
+                    None,
+                    (&[], &[]),
+                );
+                assert_eq!(
+                    geometry.scratch.len(),
+                    4,
+                    "the model still uses the shader pack"
+                );
+                assert_eq!(geometry.draws.len(), 1);
+                assert_eq!(
+                    (geometry.draws[0].pack, geometry.draws[0].shadow),
+                    (!hidden, true)
+                );
+                if hidden {
+                    assert!(
+                        rest.is_empty(),
+                        "hidden native fluid must not leak into the visible pass"
+                    );
+                } else {
+                    assert_eq!(
+                        bytemuck::cast_slice::<_, u8>(&rest),
+                        bytemuck::cast_slice::<_, u8>(&mixed[4..]),
+                        "fluid UV/layer payload cannot be sampled from the entity atlas"
+                    );
+                }
+            }
+        }
+    }
+
     #[test]
     fn posed_draws_preserve_subject_ids_overlays_and_hidden_shadow_casters() {
         let mut skin = SkinFrame {

crates/horizon-client-render/src/gfx/pack_images.rs

@@ -23,6 +23,13 @@ pub(super) struct PackImage {
 }
 
 impl PackImage {
+    pub(super) fn reset_history(&mut self) {
+        self.view = None;
+        self.copy = None;
+        self.before = None;
+        self.made_for = [0; 2];
+    }
+
     pub(super) fn sample_type(&self, features: wgpu::Features) -> wgpu::TextureSampleType {
         self.format
             .sample_type(None, Some(features))
@@ -316,6 +323,11 @@ impl StandIn {
     }
 }
 
+pub(super) fn reset_stand_ins(device: &wgpu::Device, images: &mut Vec<StandIn>) {
+    let wanted = images.iter().map(|i| (i.format, i.dimension)).collect();
+    *images = stand_ins(device, wanted);
+}
+
 /// One stand-in for each format and dimension of `wanted`.
 pub(super) fn stand_ins(
     device: &wgpu::Device,
@@ -392,6 +404,12 @@ pub(super) struct Buffers {
 }
 
 impl Buffers {
+    pub(super) fn reset_history(&mut self) {
+        self.group = None;
+        self.buffers.clear();
+        self.made_for = [0; 2];
+    }
+
     /// The layout of `objects`, bound in `stages`; each buffer is at least its entry in
     /// `minimums` long.
     pub(super) fn new(

crates/horizon-client-render/src/gfx/pack_material_tests.rs

@@ -149,6 +149,7 @@ void main() {
         post,
         wgpu::TextureFormat::Rgba8Unorm,
         world,
+        &Default::default(),
     )
     .expect("the pack runs");
     let mut pass = post

crates/horizon-client-render/src/gfx/pack_post.rs

@@ -31,6 +31,9 @@ const BUFFERS: usize = horizon_shaders::BUFFERS;
 
 mod packed;
 
+#[cfg(test)]
+mod history_reset_tests;
+
 #[cfg(test)]
 mod world_target_tests;
 
@@ -73,6 +76,9 @@ mod custom_type_tests;
 #[cfg(test)]
 mod sky_depth_tests;
 
+#[cfg(test)]
+mod end_fan_tests;
+
 #[cfg(test)]
 mod runtime_length_tests;
 
@@ -375,12 +381,13 @@ impl Gpu {
     }
 }
 
-/// A pass's pipeline: a draw, or a compute dispatch.
+/// A pass's pipeline: a draw, or a compute dispatch. Its slot is filled when the pack's
+/// pipelines are compiled (`compile`), all of them at once once the pack is laid out.
 #[derive(Clone)]
 enum Pipeline {
-    Render(wgpu::RenderPipeline),
+    Render(Slot<wgpu::RenderPipeline>),
     Compute {
-        pipeline: wgpu::ComputePipeline,
+        pipeline: Slot<wgpu::ComputePipeline>,
         /// `workGroups`, else `workGroupsRender` and the local size.
         groups: Option<[u32; 3]>,
         render: [f32; 2],
@@ -395,10 +402,12 @@ struct Pass {
     pipeline: Pipeline,
     /// The same program as vanilla blends the sky's parts (`PostProgram::vanilla_sky_blends`):
     /// without blending for the disc and the void, then with `STARS_BLEND` for the stars.
-    sky_parts: Option<[wgpu::RenderPipeline; 2]>,
+    sky_parts: Option<[Slot<wgpu::RenderPipeline>; 2]>,
     layout: wgpu::BindGroupLayout,
     ubo: wgpu::Buffer,
     block: Vec<u8>,
+    /// Shader-declared defaults must survive a reset of the mutable upload block.
+    initial_block: Vec<u8>,
     /// (index into `pack_uniforms::NAMES`, declared type, offset).
     uniforms: Vec<(Option<usize>, String, u32)>,
     samplers: Vec<Binding>,
@@ -452,9 +461,19 @@ struct Pass {
 }
 
 impl Pass {
+    /// Back to the uniform values the pass was made with, and no bind groups.
+    fn reset_history(&mut self) {
+        self.block.clone_from(&self.initial_block);
+        self.groups.clear();
+        self.portal_groups.clear();
+        for compute in &mut self.compute {
+            compute.reset_history();
+        }
+    }
+
     fn render(&self) -> &wgpu::RenderPipeline {
         match &self.pipeline {
-            Pipeline::Render(p) => p,
+            Pipeline::Render(p) => p.get().expect("compiled with its pack"),
             Pipeline::Compute { .. } => unreachable!("a compute pass draws nothing"),
         }
     }
@@ -497,6 +516,7 @@ struct Targets {
 }
 
 /// What a pack's gbuffers programs read and draw from the game's world.
+#[derive(Clone)]
 pub(super) struct World<'a> {
     /// The block atlas and its size.
     pub atlas: Option<(wgpu::TextureView, [u32; 2])>,
@@ -1225,6 +1245,7 @@ fn block_ids(
 
 /// The game's geometry a gbuffers program draws: its vertex buffers and, for flat draws
 /// (flat.rs), the layout of their bind group 1.
+#[derive(Clone)]
 pub(super) struct Geometry<'a> {
     pub buffers: &'a [Option<wgpu::VertexBufferLayout<'a>>],
     pub table: Option<&'a wgpu::BindGroupLayout>,
@@ -1268,6 +1289,177 @@ struct Resources<'a> {
     /// Bit n: shadowtex n read through a plain sampler filters linearly (`shadowtexNNearest`
     /// unset): the translator's helpers blend a gather of it (`hz_depth_linear`).
     shadow_linear: u8,
+    /// While the pack is laid out for `compile`: the pipelines its programs need. `None`
+    /// compiles each as its program is built.
+    jobs: Option<std::cell::RefCell<Vec<Job>>>,
+}
+
+impl Resources<'_> {
+    /// The slot of the render pipeline `job` makes: filled now, or by `compile` when the pack
+    /// is laid out.
+    fn render_pipeline(&self, device: &wgpu::Device, job: RenderJob) -> Slot<wgpu::RenderPipeline> {
+        let slot = Slot::default();
+        let job = Job::Render(slot.clone(), job);
+        match &self.jobs {
+            Some(jobs) => jobs.borrow_mut().push(job),
+            None => job.create(device),
+        }
+        slot
+    }
+    /// As `render_pipeline`, for a compute pipeline.
+    fn compute_pipeline(
+        &self,
+        device: &wgpu::Device,
+        job: ComputeJob,
+    ) -> Slot<wgpu::ComputePipeline> {
+        let slot = Slot::default();
+        let job = Job::Compute(slot.clone(), job);
+        match &self.jobs {
+            Some(jobs) => jobs.borrow_mut().push(job),
+            None => job.create(device),
+        }
+        slot
+    }
+}
+
+/// A pipeline, made once: `Pipeline`'s, filled by its `Job`.
+type Slot<T> = std::sync::Arc<std::sync::OnceLock<T>>;
+
+/// What a render pipeline of a pack's program is made of, kept to make it later.
+#[derive(Clone)]
+struct RenderJob {
+    label: String,
+    layout: wgpu::PipelineLayout,
+    vs: wgpu::ShaderModule,
+    fs: wgpu::ShaderModule,
+    /// The vertex buffers: stride, step mode and attributes.
+    buffers: Vec<Option<(u64, wgpu::VertexStepMode, Vec<wgpu::VertexAttribute>)>>,
+    primitive: wgpu::PrimitiveState,
+    depth_stencil: Option<wgpu::DepthStencilState>,
+    targets: Vec<Option<wgpu::ColorTargetState>>,
+}
+
+/// What a compute pipeline of a pack's program is made of.
+struct ComputeJob {
+    label: String,
+    layout: wgpu::PipelineLayout,
+    module: wgpu::ShaderModule,
+}
+
+/// A pipeline to make, and the slot it goes in.
+enum Job {
+    Render(Slot<wgpu::RenderPipeline>, RenderJob),
+    Compute(Slot<wgpu::ComputePipeline>, ComputeJob),
+}
+
+impl Job {
+    /// Makes the pipeline (the driver compiles its shaders here) into its slot.
+    fn create(&self, device: &wgpu::Device) {
+        match self {
+            Job::Render(slot, j) => {
+                let buffers: Vec<Option<wgpu::VertexBufferLayout>> = j
+                    .buffers
+                    .iter()
+                    .map(|b| {
+                        b.as_ref()
+                            .map(|(stride, step, attributes)| wgpu::VertexBufferLayout {
+                                array_stride: *stride,
+                                step_mode: *step,
+                                attributes,
+                            })
+                    })
+                    .collect();
+                let pipeline = device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
+                    label: Some(&j.label),
+                    layout: Some(&j.layout),
+                    vertex: wgpu::VertexState {
+                        module: &j.vs,
+                        entry_point: Some("main"),
+                        compilation_options: Default::default(),
+                        buffers: &buffers,
+                    },
+                    primitive: j.primitive,
+                    depth_stencil: j.depth_stencil.clone(),
+                    multisample: Default::default(),
+                    fragment: Some(wgpu::FragmentState {
+                        module: &j.fs,
+                        entry_point: Some("main"),
+                        compilation_options: Default::default(),
+                        targets: &j.targets,
+                    }),
+                    multiview_mask: None,
+                    cache: None,
+                });
+                let _ = slot.set(pipeline);
+            }
+            Job::Compute(slot, j) => {
+                let pipeline = device.create_compute_pipeline(&wgpu::ComputePipelineDescriptor {
+                    label: Some(&j.label),
+                    layout: Some(&j.layout),
+                    module: &j.module,
+                    entry_point: Some("main"),
+                    compilation_options: Default::default(),
+                    cache: None,
+                });
+                let _ = slot.set(pipeline);
+            }
+        }
+    }
+    fn label(&self) -> &str {
+        match self {
+            Job::Render(_, j) => &j.label,
+            Job::Compute(_, j) => &j.label,
+        }
+    }
+}
+
+/// Makes the pipelines of `jobs` on as many threads as the machine has cores (up to 8): the
+/// driver compiles a big pack's programs for tens of seconds one at a time, on one core. The
+/// first one wgpu or the driver refuses, with why; `None` when all are made.
+///
+/// A refusal doesn't stop the others: every job is made, so that the serial rebuild `new` then
+/// runs finds the driver's shader cache warm instead of compiling the rest cold, one at a time.
+/// `cancel` set stops handing out jobs: the caller then drops the pack (`PackPost::new`).
+fn compile(
+    device: &wgpu::Device,
+    jobs: &[Job],
+    cancel: &std::sync::atomic::AtomicBool,
+) -> Option<(String, String)> {
+    use std::sync::atomic::{AtomicUsize, Ordering};
+    let threads = std::thread::available_parallelism()
+        .map_or(1, |n| n.get())
+        .clamp(1, 8)
+        .min(jobs.len().max(1));
+    let next = AtomicUsize::new(0);
+    let refused = std::sync::Mutex::new(None);
+    std::thread::scope(|scope| {
+        for _ in 0..threads {
+            scope.spawn(|| {
+                while !cancel.load(Ordering::Relaxed)
+                    && let Some(job) = jobs.get(next.fetch_add(1, Ordering::Relaxed))
+                {
+                    if let Err(e) = checked(device, || job.create(device)) {
+                        let mut refused = refused.lock().unwrap_or_else(|e| e.into_inner());
+                        refused.get_or_insert((job.label().to_owned(), e));
+                    }
+                }
+            });
+        }
+    });
+    refused.into_inner().unwrap_or_else(|e| e.into_inner())
+}
+
+/// Vertex buffer layouts owned, for a `RenderJob`.
+fn owned_buffers(
+    buffers: &[Option<wgpu::VertexBufferLayout<'_>>],
+) -> Vec<Option<(u64, wgpu::VertexStepMode, Vec<wgpu::VertexAttribute>)>> {
+    buffers
+        .iter()
+        .map(|b| {
+            b.as_ref()
+                .map(|b| (b.array_stride, b.step_mode, b.attributes.to_vec()))
+        })
+        .collect()
 }
 
 /// A program's bind group layout (its uniform block, samplers and images) and how each sampler
@@ -1876,60 +2068,47 @@ fn build_pass(
         packed::quantise_outputs(&mut fragment, &packed_outputs);
         packed::bitcast_outputs(&mut fragment, &int_outputs);
         let (vs, fs) = (module(program.vertex), module(fragment));
-        let descriptor = |targets: &[Option<wgpu::ColorTargetState>]| {
-            device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
-                label: Some(&p.name),
-                layout: Some(&pipeline_layout),
-                vertex: wgpu::VertexState {
-                    module: &vs,
-                    entry_point: Some("main"),
-                    compilation_options: Default::default(),
-                    // A geometry stage reads its vertices itself.
-                    buffers: geometry
-                        .filter(|_| p.geometry_triangles == 0)
-                        .map_or(&[], |g| g.buffers),
+        let job = RenderJob {
+            label: p.name.clone(),
+            layout: pipeline_layout,
+            vs,
+            fs,
+            // A geometry stage reads its vertices itself.
+            buffers: geometry
+                .filter(|_| p.geometry_triangles == 0)
+                .map_or_else(Vec::new, |g| owned_buffers(g.buffers)),
+            // Rows flipped to GL's turn front faces clockwise.
+            primitive: wgpu::PrimitiveState {
+                front_face: wgpu::FrontFace::Cw,
+                cull_mode: geometry
+                    .filter(|g| g.cull && p.geometry_triangles == 0)
+                    .map(|_| wgpu::Face::Back),
+                ..Default::default()
+            },
+            depth_stencil: geometry.map(|g| wgpu::DepthStencilState {
+                format: wgpu::TextureFormat::Depth32Float,
+                depth_write_enabled: Some(g.depth_write),
+                depth_compare: Some(wgpu::CompareFunction::LessEqual),
+                stencil: Default::default(),
+                bias: if p.name == "gbuffers_damagedblock" {
+                    wgpu::DepthBiasState {
+                        constant: -10,
+                        slope_scale: -1.0,
+                        clamp: 0.0,
+                    }
+                } else {
+                    Default::default()
                 },
-                // Rows flipped to GL's turn front faces clockwise.
-                primitive: wgpu::PrimitiveState {
-                    front_face: wgpu::FrontFace::Cw,
-                    cull_mode: geometry
-                        .filter(|g| g.cull && p.geometry_triangles == 0)
-                        .map(|_| wgpu::Face::Back),
-                    ..Default::default()
-                },
-                depth_stencil: geometry.map(|g| wgpu::DepthStencilState {
-                    format: wgpu::TextureFormat::Depth32Float,
-                    depth_write_enabled: Some(g.depth_write),
-                    depth_compare: Some(wgpu::CompareFunction::LessEqual),
-                    stencil: Default::default(),
-                    bias: if p.name == "gbuffers_damagedblock" {
-                        wgpu::DepthBiasState {
-                            constant: -10,
-                            slope_scale: -1.0,
-                            clamp: 0.0,
-                        }
-                    } else {
-                        Default::default()
-                    },
-                }),
-                multisample: Default::default(),
-                fragment: Some(wgpu::FragmentState {
-                    module: &fs,
-                    entry_point: Some("main"),
-                    compilation_options: Default::default(),
-                    targets,
-                }),
-                multiview_mask: None,
-                cache: None,
-            })
+            }),
+            targets: targets.to_vec(),
         };
-        let pipeline = descriptor(&targets);
         // The program's own blend replaced by vanilla's for the part; a buffer's own
         // `blend.<program>.<buffer>` still applies (Iris 1.11.7 blended the sky disc into that
-        // buffer only, with a probe pack of ours).
+        // buffer only, with a probe pack of ours). Two more pipelines of the program, made
+        // with the others (`compile`).
         let sky_parts = p.vanilla_sky_blends.then(|| {
             [None, Some(blend_state(horizon_shaders::STARS_BLEND))].map(|part| {
-                let targets: Vec<_> = (targets.iter().enumerate())
+                let targets: Vec<_> = (job.targets.iter().enumerate())
                     .map(|(l, t)| {
                         let (own, blendable) = own_blends.get(l).copied().unwrap_or((None, false));
                         t.clone().map(|t| wgpu::ColorTargetState {
@@ -1938,10 +2117,16 @@ fn build_pass(
                         })
                     })
                     .collect();
-                descriptor(&targets)
+                pack.render_pipeline(
+                    device,
+                    RenderJob {
+                        targets,
+                        ..job.clone()
+                    },
+                )
             })
         });
-        (layout, pipeline, sky_parts)
+        (layout, pack.render_pipeline(device, job), sky_parts)
     });
     let (layout, pipeline, sky_parts) = match created {
         Ok(created) => created,
@@ -1973,6 +2158,7 @@ fn build_pass(
             mapped_at_creation: false,
         }),
         block: interface.initial_values.clone(),
+        initial_block: interface.initial_values.clone(),
         uniforms: interface
             .uniforms
             .iter()
@@ -2080,15 +2266,12 @@ fn build_compute(
             label: Some(&name),
             source: wgpu::ShaderSource::Naga(std::borrow::Cow::Owned(module)),
         });
-        let pipeline = device.create_compute_pipeline(&wgpu::ComputePipelineDescriptor {
-            label: Some(&name),
-            layout: Some(&pipeline_layout),
-            module: &module,
-            entry_point: Some("main"),
-            compilation_options: Default::default(),
-            cache: None,
-        });
-        (layout, pipeline)
+        let job = ComputeJob {
+            label: name.clone(),
+            layout: pipeline_layout,
+            module,
+        };
+        (layout, pack.compute_pipeline(device, job))
     });
     let (layout, pipeline) = match created {
         Ok(created) => created,
@@ -2108,6 +2291,7 @@ fn build_compute(
             mapped_at_creation: false,
         }),
         block: interface.initial_values.clone(),
+        initial_block: interface.initial_values.clone(),
         uniforms: interface
             .uniforms
             .iter()
@@ -2156,17 +2340,73 @@ pub struct Refused {
     pub notes: Vec<String>,
 }
 
+impl Refused {
+    /// The reason of a build stopped by its `cancel` flag (`PackPost::new`).
+    const CANCELLED: &str = "cancelled";
+    fn cancelled(notes: Vec<String>) -> Self {
+        Self {
+            reason: Self::CANCELLED.into(),
+            notes,
+        }
+    }
+    /// Whether the build was cancelled (another pack or dimension asked for): not the pack's
+    /// fault, so nothing to report to the player.
+    pub fn is_cancelled(&self) -> bool {
+        self.reason == Self::CANCELLED
+    }
+}
+
 impl PackPost {
     /// Builds the pipelines of `post` for a screen of `screen` format. An error when the pack
     /// can't show anything on the screen: the game turns it off, as a pack that fails to load.
+    ///
+    /// The pack is laid out first and its pipelines are made after, all at once (`compile`).
+    /// When wgpu or the driver refuses one, the pack is built again a program at a time, so that
+    /// the program is skipped with its note as it always was.
+    ///
+    /// `cancel` set (the pack isn't wanted any more) stops the build between programs: a refusal
+    /// whose `is_cancelled` is true.
     pub fn new(
+        device: &wgpu::Device,
+        queue: &wgpu::Queue,
+        adapter: &wgpu::Adapter,
+        post: Post,
+        screen: wgpu::TextureFormat,
+        world: World<'_>,
+        cancel: &std::sync::atomic::AtomicBool,
+    ) -> Result<Self, Refused> {
+        use std::sync::atomic::Ordering;
+        let spare = (post.clone(), world.clone());
+        let (built, jobs) = Self::build(device, queue, adapter, post, screen, world, true, cancel)?;
+        let refused = compile(device, &jobs, cancel);
+        // Some pipelines may be left unmade: the pack can't draw.
+        if cancel.load(Ordering::Relaxed) {
+            return Err(Refused::cancelled(built.notes));
+        }
+        let Some((program, refused)) = refused else {
+            return Ok(built);
+        };
+        log::warn!(
+            "shader pack: {program} was refused ({refused}): building it again a program at a time"
+        );
+        drop((built, jobs));
+        let (post, world) = spare;
+        Self::build(device, queue, adapter, post, screen, world, false, cancel)
+            .map(|(built, _)| built)
+    }
+
+    /// `new`'s work: with `defer`, the pipelines are left to make (the jobs returned).
+    #[allow(clippy::too_many_arguments)]
+    fn build(
         device: &wgpu::Device,
         queue: &wgpu::Queue,
         adapter: &wgpu::Adapter,
         mut post: Post,
         screen: wgpu::TextureFormat,
         world: World<'_>,
-    ) -> Result<Self, Refused> {
+        defer: bool,
+        cancel: &std::sync::atomic::AtomicBool,
+    ) -> Result<(Self, Vec<Job>), Refused> {
         // What the pack's shaders need of its storage buffers, before its parts move out.
         let minimums = post.buffer_minimums();
         let features = device.features();
@@ -2318,8 +2558,13 @@ impl PackPost {
             shadow_linear: (0..2)
                 .filter(|&n| !shadow_config.nearest[n])
                 .fold(0, |m, n| m | 1 << n),
+            jobs: defer.then(Default::default),
         };
         let mut build = |mut p: horizon_shaders::PostProgram, geometry: Option<&Geometry<'_>>| {
+            // Not wanted any more: the rest is skipped and the build refused below.
+            if cancel.load(std::sync::atomic::Ordering::Relaxed) {
+                return None;
+            }
             let in_shadow = p.group.shadow();
             let mut compute = std::mem::take(&mut p.compute);
             if !gpu.compute {
@@ -2668,6 +2913,9 @@ impl PackPost {
             .filter(|p| !skip.split(',').any(|s| s == p.name))
             .filter_map(|p| build(p, None))
             .collect();
+        if cancel.load(std::sync::atomic::Ordering::Relaxed) {
+            return Err(Refused::cancelled(notes));
+        }
         let stand_ins = pack_images::stand_ins(device, stand_ins.take());
         // Terrain in two parts draws both or neither: one alone would leave the other part's
         // terrain undrawn. Without either, the game draws all terrain, as when the terrain
@@ -3001,7 +3249,10 @@ impl PackPost {
         let white = [255u8; 4];
         let black = [0u8; 4];
         let flat_normal = [128u8, 128, 255, 255];
-        Ok(Self {
+        let jobs = (pack.jobs.as_ref())
+            .map(std::cell::RefCell::take)
+            .unwrap_or_default();
+        let built = Self {
             notes,
             setup_pending: true,
             passes,
@@ -3124,23 +3375,7 @@ impl PackPost {
                 .create_view(&Default::default()),
             textures,
             shadow: (
-                device
-                    .create_texture(&wgpu::TextureDescriptor {
-                        label: Some("Shader pack shadow stand-in"),
-                        size: wgpu::Extent3d {
-                            width: 1,
-                            height: 1,
-                            depth_or_array_layers: 1,
-                        },
-                        mip_level_count: 1,
-                        sample_count: 1,
-                        dimension: wgpu::TextureDimension::D2,
-                        format: wgpu::TextureFormat::Depth32Float,
-                        usage: wgpu::TextureUsages::TEXTURE_BINDING
-                            | wgpu::TextureUsages::RENDER_ATTACHMENT,
-                        view_formats: &[],
-                    })
-                    .create_view(&Default::default()),
+                super::pack_shadow::stand_in(device),
                 device.create_sampler(&wgpu::SamplerDescriptor {
                     label: Some("Shader pack shadow"),
                     compare: Some(wgpu::CompareFunction::LessEqual),
@@ -3186,7 +3421,76 @@ impl PackPost {
                 u
             },
             shadow_cache: Default::default(),
-        })
+        };
+        Ok((built, jobs))
+    }
+
+    /// `Renderer::finish_sequence_frame`: the centre depth the finished frame copied.
+    pub fn take_center_depth(&mut self, device: &wgpu::Device) -> Result<(), String> {
+        self.center_depth
+            .as_mut()
+            .ok_or("the shader pack copied no centre depth")?
+            .take_completed(device)
+            .map(|_| ())
+    }
+
+    /// Forgets what the pack kept from earlier frames, so the next frame draws as a freshly
+    /// loaded pack's first: buffers, images, storage buffers and shadow maps start over (made
+    /// again at their sizes when next drawn), the frame uniforms' history, the custom uniforms
+    /// and the centre depth too. Compiled programs and the pack's textures stay.
+    pub fn reset_history(&mut self, device: &wgpu::Device) {
+        self.uniforms.reset_history();
+        // A parsed pack's custom uniforms start at tick 0's seed, before any frame of the world.
+        self.custom.restart_at(0);
+        self.custom.forget_world();
+        self.center_depth = None;
+        self.targets = None;
+        self.main = 0;
+        self.mips_valid = 0;
+        self.rgb_unset = true;
+        self.final_target = None;
+        self.blit_group = None;
+        self.page_groups.clear();
+        for image in &mut self.images {
+            image.reset_history();
+        }
+        self.buffers.reset_history();
+        pack_images::reset_stand_ins(device, &mut self.stand_ins);
+        if let Some(shadow) = &mut self.shadow_targets {
+            shadow.reset_history(device, &self.uniforms.shadow);
+        }
+        self.shadow.0 = super::pack_shadow::stand_in(device);
+        self.shadow_cleared = false;
+        self.shadow_cache = Default::default();
+        self.setup_pending = true;
+        self.portal_texture = None;
+        self.portal_rect = [0.0; 4];
+        let sky = self
+            .sky
+            .iter_mut()
+            .flat_map(|s| s.basic.iter_mut().chain(&mut s.textured));
+        let entities = self
+            .entities
+            .iter_mut()
+            .flat_map(|e| e.passes.iter_mut().chain(&mut e.shadow).flatten());
+        for pass in self
+            .passes
+            .iter_mut()
+            .chain(&mut self.terrain)
+            .chain(&mut self.terrain_cutout)
+            .chain(&mut self.water)
+            .chain(sky)
+            .chain(entities)
+            .chain(&mut self.clouds)
+            .chain(&mut self.lines)
+            .chain(self.weather.iter_mut().flatten())
+            .chain(self.hand.iter_mut().map(|h| &mut h.0))
+            .chain(&mut self.shadow_terrain)
+            .chain(&mut self.shadow_water)
+            .chain(&mut self.shadow_comp)
+        {
+            pass.reset_history();
+        }
     }
 
     /// Writes `pass`'s uniforms for a target of `out` pixels; its bind group for the buffers'
@@ -3446,6 +3750,7 @@ impl PackPost {
         else {
             return;
         };
+        let pipeline = pipeline.get().expect("compiled with its pack");
         let groups = groups.unwrap_or_else(|| {
             let n = |k: usize| (size[k] as f32 * render[k] / local[k] as f32).ceil() as u32;
             [n(0), n(1), 1]
@@ -3660,8 +3965,8 @@ impl PackPost {
                 pass.sky_parts
                     .as_ref()
                     .and_then(|[plain, stars]| match part.stage {
-                        "SKY" | "VOID" => Some(plain),
-                        "STARS" => Some(stars),
+                        "SKY" | "VOID" => plain.get(),
+                        "STARS" => stars.get(),
                         _ => None,
                     });
             rp.set_pipeline(part_pipeline.unwrap_or(pass.render()));
@@ -3940,7 +4245,7 @@ impl PackPost {
         frame: &super::Frame,
         terrain: &mut TerrainDraw<'_>,
     ) {
-        if super::sky_visible(frame) {
+        if super::sky_visible(frame) || super::end_fog_sky(frame) {
             self.draw_sky(device, queue, encoder, size, frame);
         }
         self.draw_terrain(device, queue, encoder, size, TerrainList::Solid, terrain);
@@ -5346,6 +5651,57 @@ mod tests {
         assert_eq!(used, [1, 2, 3]);
     }
 
+    /// A pack's pipelines are made together on several threads: each lands in its pass's slot,
+    /// and one wgpu refuses comes back by name (the pack is then built a program at a time).
+    #[test]
+    fn pipelines_compile_together_and_a_refused_one_is_named() {
+        let instance = crate::gfx::test_gpu::instance();
+        let Ok(adapter) = pollster::block_on(instance.request_adapter(&Default::default())) else {
+            return;
+        };
+        let Ok((device, _queue)) = pollster::block_on(adapter.request_device(&Default::default()))
+        else {
+            return;
+        };
+        let layout = device.create_pipeline_layout(&Default::default());
+        let module = |source: &str| {
+            device.create_shader_module(wgpu::ShaderModuleDescriptor {
+                label: None,
+                source: wgpu::ShaderSource::Wgsl(source.into()),
+            })
+        };
+        let job = |label: &str, module: wgpu::ShaderModule| {
+            let slot = Slot::default();
+            let job = ComputeJob {
+                label: label.into(),
+                layout: layout.clone(),
+                module,
+            };
+            (slot.clone(), Job::Compute(slot, job))
+        };
+        let plain = "@compute @workgroup_size(1) fn main() {}";
+        let go = std::sync::atomic::AtomicBool::new(false);
+        let (slots, jobs): (Vec<_>, Vec<_>) = (0..12)
+            .map(|i| job(&format!("composite{i}"), module(plain)))
+            .unzip();
+        // Cancelled before it starts: nothing is made (`new` then drops the pack).
+        assert_eq!(compile(&device, &jobs, &true.into()), None);
+        assert!(slots.iter().all(|s| s.get().is_none()));
+        assert_eq!(compile(&device, &jobs, &go), None);
+        assert!(slots.iter().all(|s| s.get().is_some()));
+        // A binding the layout doesn't have: wgpu refuses the pipeline.
+        let bound = "@group(0) @binding(0) var<storage, read_write> b: array<u32>;\n\
+                     @compute @workgroup_size(1) fn main() { b[0] = 1u; }";
+        let (_, bad) = job("deferred3", module(bound));
+        let (slots, mut jobs): (Vec<_>, Vec<_>) =
+            (0..4).map(|i| job(&format!("c{i}"), module(plain))).unzip();
+        jobs.insert(2, bad);
+        let (program, _why) = compile(&device, &jobs, &go).expect("the pipeline is refused");
+        assert_eq!(program, "deferred3");
+        // The refusal stops none of the others: they are all made.
+        assert!(slots.iter().all(|s| s.get().is_some()));
+    }
+
     /// #3525: naga's SPIR-V writer panicked on Photon's gbuffers programs as the pipeline was
     /// made. Such a panic skips the pass, as a validation error does, and the device goes on.
     #[test]
@@ -5435,6 +5791,7 @@ mod tests {
             released: std::cell::Cell::new(("", 0)),
             stand_ins: &stand_ins,
             shadow_linear: 0,
+            jobs: None,
         };
         let reads = |group: Group| {
             let (_, samplers, ..) = bindings(
@@ -5529,6 +5886,7 @@ mod tests {
             released: std::cell::Cell::new(("", 0)),
             stand_ins: &stand_ins,
             shadow_linear: 0,
+            jobs: None,
             packed: [None; BUFFERS],
         };
         let (_, samplers, ..) = bindings(
@@ -5612,6 +5970,7 @@ mod tests {
             released: std::cell::Cell::new(("", 0)),
             stand_ins: &stand_ins,
             shadow_linear: 0,
+            jobs: None,
         };
         let mut notes = Vec::new();
         let (.., images) = bindings(
@@ -5754,6 +6113,7 @@ mod tests {
             released: std::cell::Cell::new(("", 0)),
             stand_ins: &stand_ins,
             shadow_linear: 0,
+            jobs: None,
         };
         let draws = DrawUniforms::new(&device);
         let mut notes = Vec::new();

crates/horizon-client-render/src/gfx/pack_post/atlas_mip_tests.rs

@@ -99,6 +99,7 @@ fn the_atlas_blends_its_two_nearest_levels() {
             weather: false,
             hand: false,
         },
+        &Default::default(),
     )
     .expect("the pack runs");
     for p in gpu.render(&mut post, [4, 4]) {

crates/horizon-client-render/src/gfx/pack_post/depth_test.rs

@@ -83,6 +83,7 @@ impl Gpu {
             post,
             T::Rgba8Unorm,
             world,
+            &Default::default(),
         )
         .expect("the pack runs");
         assert!(
@@ -593,6 +594,7 @@ pub(super) fn fixture_frame(hud: &HudBatch) -> Frame<'_> {
         skybox: false,
         end_sky: false,
         end_sky_sprite: None,
+        boss_world_fog: false,
         environment_fog: None,
         water_fog: [0.0; 3],
         fog: None,

crates/horizon-client-render/src/gfx/pack_post/destination_tests.rs

@@ -244,6 +244,7 @@ impl Fixture {
                 weather: false,
                 hand: false,
             },
+            &Default::default(),
         )
     }
 
@@ -431,6 +432,7 @@ fn fixture_frame(hud: &HudBatch) -> Frame<'_> {
         skybox: false,
         end_sky: false,
         end_sky_sprite: None,
+        boss_world_fog: false,
         environment_fog: None,
         water_fog: [0.0; 3],
         fog: None,

crates/horizon-client-render/src/gfx/pack_post/end_fan_tests.rs

@@ -0,0 +1,151 @@
+//! In the End, while the dragon fight's world fog leaves out vanilla's sky, a pack's
+//! `gbuffers_skybasic` draws a fan in the fog colour, as our probe packs read it in Iris 1.11.7.
+//! Original fixture, no pack files.
+use super::depth_test::{Gpu, SIZE, VERTEX, fixture_frame};
+use super::*;
+use crate::hud::HudBatch;
+use wgpu::TextureFormat as T;
+
+/// `gbuffers_skybasic` writes its vertex colour into colortex0 and `gl_Vertex` into colortex1
+/// (32-bit floats). final shows, on the picture's top half, `gl_Vertex.y` of the view's lower
+/// half as a 24-bit integer ((y + 64) * 65536), and on its bottom half colortex0 of the view's
+/// upper half.
+fn files() -> Vec<(String, String)> {
+    vec![
+        ("shaders.properties".into(), "blend.gbuffers_skybasic=off\n".into()),
+        (
+            "gbuffers_skybasic.vsh".into(),
+            "#version 120\nvarying vec4 color;\nvarying vec3 at;\nvoid main() {\n\
+             \x20   gl_Position = ftransform();\n    color = gl_Color;\n    at = gl_Vertex.xyz;\n}\n"
+                .into(),
+        ),
+        (
+            "gbuffers_skybasic.fsh".into(),
+            "#version 120\nvarying vec4 color;\nvarying vec3 at;\n/* DRAWBUFFERS:01 */\n\
+             void main() {\n    gl_FragData[0] = color;\n    gl_FragData[1] = vec4(at, 1.0);\n}\n"
+                .into(),
+        ),
+        ("final.vsh".into(), VERTEX.into()),
+        (
+            "final.fsh".into(),
+            "#version 130\n/*\nconst int colortex1Format = RGBA32F;\n*/\n\
+             uniform sampler2D colortex0;\nuniform sampler2D colortex1;\nvarying vec2 uv;\n\
+             void main() {\n\
+             \x20   float y = texelFetch(colortex1, ivec2(gl_FragCoord.xy) - ivec2(0, 8), 0).y;\n\
+             \x20   uint n = min(uint((y + 64.0) * 65536.0 + 0.5), 16777215u);\n\
+             \x20   vec4 at = vec4(uvec4(n >> 16u, (n >> 8u) & 255u, n & 255u, 255u)) / 255.0;\n\
+             \x20   gl_FragColor = uv.y > 0.5 ? at : texelFetch(colortex0, ivec2(gl_FragCoord.xy) + ivec2(0, 8), 0);\n}\n"
+                .into(),
+        ),
+    ]
+}
+
+/// The pack's picture of the fixture's frame (16 pixels square, 90° field of view, looking level
+/// toward +Z) in the End, the world having left the far plane everywhere.
+fn picture(gpu: &Gpu, boss_world_fog: bool) -> Vec<[u8; 4]> {
+    let color = gpu.texture(T::Rgba8Unorm);
+    let depth = gpu.texture(T::Depth32Float);
+    gpu.clear(&color, &depth, 0.0);
+    let mut post = gpu.load(
+        files(),
+        World {
+            atlas: None,
+            material_maps: None,
+            lightmap: color.clone(),
+            terrain: None,
+            block_ids: &[],
+            sprite_rects: &[],
+            celestial: None,
+            gui_size: SIZE,
+            clouds: None,
+            weather: false,
+            hand: false,
+        },
+        horizon_shaders::GameInputs {
+            sky: Some(super::super::pack_sky::inputs()),
+            ..Default::default()
+        },
+    );
+    assert!(post.sky.is_some(), "{:?}", post.notes);
+    let hud = HudBatch::new(SIZE);
+    let mut frame = fixture_frame(&hud);
+    frame.title = false;
+    frame.end_sky = true;
+    frame.boss_world_fog = boss_world_fog;
+    frame.detail_distance = 192.0;
+    frame.fog = Some(crate::fog::FogData {
+        color: [0.2, 0.4, 0.6, 1.0],
+        environmental_start: 0.0,
+        environmental_end: 96.0,
+        render_distance_start: 172.8,
+        render_distance_end: 192.0,
+        sky_end: 96.0,
+        cloud_end: 96.0,
+    });
+    gpu.render(&mut post, &color, &depth, &frame, &mut |_, _, _, _| {})
+}
+
+/// Where the view ray through pixel (`column`, `row`) meets the fan: from (0, -16, 0) to eight
+/// points 16 above the eye at radius 192, every 45° from +Z. None when it passes above the rim.
+fn fan_height(column: usize, row: usize) -> Option<f64> {
+    let side = |i: usize| (i as f64 + 0.5) / 8.0 - 1.0;
+    // The fan is mirrored across x = 0, so either sign of the view's x does.
+    let ray = glam::DVec3::new(side(column), -side(row), 1.0);
+    let azimuth = ray.x.atan2(ray.z).to_degrees();
+    let edge = (azimuth / 45.0).floor();
+    let rim = |k: f64| {
+        let a = (k * 45.0).to_radians();
+        glam::DVec3::new(192.0 * a.sin(), 16.0, 192.0 * a.cos())
+    };
+    let apex = glam::DVec3::new(0.0, -16.0, 0.0);
+    let normal = (rim(edge) - apex).cross(rim(edge + 1.0) - apex);
+    let along = apex.dot(normal) / ray.dot(normal);
+    let hit = ray * along;
+    (along > 0.0 && hit.y <= 16.0).then_some(hit.y)
+}
+
+#[test]
+fn the_end_under_the_dragons_fog_has_the_packs_fan() {
+    let Some(gpu) = Gpu::new() else { return };
+    let pixels = picture(&gpu, true);
+    let width = SIZE[0] as usize;
+    // Below the horizon: every pixel sees the fan, at the height the planes give (to 0.02:
+    // the GPU interpolates `gl_Vertex` across triangles 192 blocks wide; it came within 0.008).
+    for row in 8..16 {
+        for column in 0..width {
+            let p = pixels[(row - 8) * width + column];
+            let got = f64::from(u32::from(p[0]) << 16 | u32::from(p[1]) << 8 | u32::from(p[2]))
+                / 65536.0
+                - 64.0;
+            let expected = fan_height(column, row).expect("below the horizon");
+            assert!(
+                (got - expected).abs() < 0.02,
+                "row {row}, column {column}: gl_Vertex.y {got}, expected {expected}"
+            );
+        }
+    }
+    // Above it: only the row just over the horizon reaches the fan (the rim stands 4.8° up),
+    // drawn in the fog colour; above that, the world's grey stays.
+    for row in 0..8 {
+        for column in 0..width {
+            let p = pixels[(row + 8) * width + column];
+            let expected = match fan_height(column, row) {
+                Some(_) => [51, 102, 153, 255],
+                None => [16, 16, 16, 255],
+            };
+            assert_eq!(p, expected, "row {row}, column {column}");
+        }
+        assert_eq!(fan_height(0, row).is_some(), row == 7, "row {row}");
+    }
+}
+
+/// The End without the fog: vanilla's End sky, which no `gbuffers_skybasic` draws.
+#[test]
+fn the_end_without_the_fog_has_no_fan() {
+    let Some(gpu) = Gpu::new() else { return };
+    let pixels = picture(&gpu, false);
+    let width = SIZE[0] as usize;
+    for (i, p) in pixels[8 * width..].iter().enumerate() {
+        assert_eq!(*p, [16, 16, 16, 255], "pixel {i}");
+    }
+}

crates/horizon-client-render/src/gfx/pack_post/history_reset_tests.rs

@@ -0,0 +1,109 @@
+//! `PackPost::reset_history`: a pack reset after some frames draws as a freshly loaded one.
+use super::destination_tests::Fixture;
+use std::io::{Cursor, Write};
+
+#[test]
+#[ignore = "requires a host GPU with compute and fragment storage"]
+fn a_reset_pack_draws_its_buffers_images_storage_and_shadow_from_the_start() {
+    let gpu = Fixture::new().expect("a GPU is required for this reset regression");
+    let mut zip = zip::ZipWriter::new(Cursor::new(Vec::new()));
+    let mut add = |name: &str, source: &str| {
+        zip.start_file(
+            format!("shaders/{name}"),
+            zip::write::SimpleFileOptions::default(),
+        )
+        .unwrap();
+        zip.write_all(source.as_bytes()).unwrap();
+    };
+    let vertex = "#version 120\nvarying vec2 uv;\nvoid main(){uv=gl_MultiTexCoord0.xy;gl_Position=ftransform();}\n";
+    let state = "layout(std430,binding=0) buffer State { uint setups; uint frames; } state;\n";
+    let compute = "#version 430\nlayout(local_size_x=1) in;\nconst ivec3 workGroups=ivec3(1);\n";
+    add(
+        "setup.csh",
+        &format!("{compute}{state}void main(){{state.setups+=1u;}}\n"),
+    );
+    add(
+        "begin.csh",
+        &format!(
+            "{compute}{state}layout(r32ui) uniform uimage2D imgCounter;\n\
+        void main(){{state.frames+=1u;imageStore(imgCounter,ivec2(0),uvec4(imageLoad(imgCounter,ivec2(0)).r+1u));}}\n"
+        ),
+    );
+    for name in ["composite", "shadowcomp"] {
+        add(&format!("{name}.vsh"), vertex);
+        let target = if name == "composite" { 2 } else { 0 };
+        let (declarations, value) = if name == "composite" {
+            ("", "vec4(0.125)")
+        } else {
+            (
+                "uniform sampler2D shadowcolor0;varying vec2 uv;",
+                "texture2D(shadowcolor0,uv)+vec4(0.125)",
+            )
+        };
+        add(
+            &format!("{name}.fsh"),
+            &format!(
+                "#version 120\n/* RENDERTARGETS:{target} */\n\
+            {declarations}\nvoid main(){{gl_FragData[0]={value};}}\n"
+            ),
+        );
+    }
+    add("final.vsh", vertex);
+    add(
+        "final.fsh",
+        &format!(
+            "#version 430 compatibility\n{state}\
+        uniform sampler2D colortex2;uniform sampler2D shadowcolor0;uniform usampler2D texCounter;\n\
+        const bool colortex2Clear=false;const bool shadowcolor0Clear=false;\n\
+        const int shadowMapResolution=16;uniform float baseline=0.375;varying vec2 uv;\n\
+        void main(){{gl_FragColor=gl_FragCoord.x<8.0?\
+        vec4(texture(colortex2,uv).r,float(texelFetch(texCounter,ivec2(0),0).r)/8.0,float(state.frames)/8.0,1):\
+        vec4(texture(shadowcolor0,uv).r,float(state.setups)/8.0,baseline,1);}}\n"
+        ),
+    );
+    add(
+        "shaders.properties",
+        "shadow.enabled=true\nbufferObject.0=8\n\
+        image.imgCounter=texCounter RED_INTEGER R32UI UNSIGNED_INT false false 1 1\n\
+        blend.composite=ONE ONE ONE ONE\n",
+    );
+    let pack =
+        horizon_shaders::Pack::from_zip_bytes("original-reset", zip.finish().unwrap().into_inner())
+            .unwrap();
+    let mut macros = horizon_shaders::Macros::standard();
+    let (properties, _) = horizon_shaders::read_properties(&pack, &mut macros);
+    let load = || horizon_shaders::load_post(&pack, "", &properties, &macros, &Default::default());
+    let mut post = gpu.try_build(load()).expect("reset fixture compiles");
+    let mut fresh = gpu.try_build(load()).expect("fresh control compiles");
+    let check = |pixels: &[[u8; 4]], frame: u8| {
+        let counter = 32 * frame;
+        for (i, pixel) in pixels.iter().enumerate() {
+            let expected = if i % 16 < 8 {
+                [counter, counter, counter, 255]
+            } else {
+                [counter, 32, 96, 255]
+            };
+            assert!(
+                pixel.iter().zip(expected).all(|(a, b)| a.abs_diff(b) <= 1),
+                "frame {frame}, pixel {i}: {pixel:?} != {expected:?}"
+            );
+        }
+    };
+    for frame in 1..=3 {
+        check(&gpu.render(&mut post, [16, 16]), frame);
+    }
+    // At the same size too: the retained colortex2 and shadowcolor0, the image and
+    // the storage buffer start over, and setup runs once again. The control is a pack never
+    // reset.
+    for _ in 0..2 {
+        post.reset_history(&gpu.device);
+        for frame in 1..=2 {
+            let pixels = gpu.render(&mut post, [16, 16]);
+            check(&pixels, frame);
+            if frame == 1 {
+                assert_eq!(pixels, gpu.render(&mut fresh, [16, 16]));
+            }
+        }
+        fresh.reset_history(&gpu.device);
+    }
+}

crates/horizon-client-render/src/gfx/pack_post/weather_depth_tests.rs

@@ -187,6 +187,7 @@ fn pack(
             weather: true,
             hand: false,
         },
+        &Default::default(),
     )
     .expect("weather pack runs");
     assert!(

crates/horizon-client-render/src/gfx/pack_post/world_target_tests.rs

@@ -304,6 +304,7 @@ fn pack_with(
             weather: false,
             hand: false,
         },
+        &Default::default(),
     )
     .expect("the pack runs");
     assert!(post.notes.is_empty(), "{:?}", post.notes);
@@ -400,6 +401,7 @@ fn frame(hud: &HudBatch) -> Frame<'_> {
         skybox: false,
         end_sky: false,
         end_sky_sprite: None,
+        boss_world_fog: false,
         environment_fog: None,
         water_fog: [0.0; 3],
         fog: None,

crates/horizon-client-render/src/gfx/pack_shadow.rs

@@ -76,7 +76,50 @@ fn target(
     (texture, view)
 }
 
+/// The depth stand-in is initialized to no shadow on the next pack render.
+pub(super) fn stand_in(device: &wgpu::Device) -> wgpu::TextureView {
+    device
+        .create_texture(&wgpu::TextureDescriptor {
+            label: Some("Shader pack shadow stand-in"),
+            size: wgpu::Extent3d {
+                width: 1,
+                height: 1,
+                depth_or_array_layers: 1,
+            },
+            mip_level_count: 1,
+            sample_count: 1,
+            dimension: wgpu::TextureDimension::D2,
+            format: wgpu::TextureFormat::Depth32Float,
+            usage: wgpu::TextureUsages::TEXTURE_BINDING | wgpu::TextureUsages::RENDER_ATTACHMENT,
+            view_formats: &[],
+        })
+        .create_view(&Default::default())
+}
+
 impl ShadowTargets {
+    pub fn reset_history(&mut self, device: &wgpu::Device, shadow: &horizon_shaders::Shadow) {
+        let mut colors = 0;
+        let mut doubled = 0;
+        let formats = std::array::from_fn(|n| match &self.color[n] {
+            Some([a, b]) => {
+                colors |= 1 << n;
+                if a.texture() != b.texture() {
+                    doubled |= 1 << n;
+                }
+                a.texture().format()
+            }
+            None => wgpu::TextureFormat::Rgba8Unorm,
+        });
+        *self = Self::new(
+            device,
+            shadow,
+            formats,
+            colors,
+            doubled,
+            self.depth1.is_some(),
+        );
+    }
+
     /// The buffers of `shadow` the pack uses: `colors` (bit n: shadowcolor n), `depth1` when
     /// some program reads `shadowtex1`, `doubled` (bit n: shadowcolor n needs a B texture). The
     /// resolution is kept within the device's limit.

crates/horizon-client-render/src/gfx/pack_sky.rs

@@ -22,6 +22,8 @@ const SUNSET_APEX: u32 = 1;
 const SUNSET_RIM: u32 = 2;
 const STAR: u32 = 3;
 const VOID: u32 = 4;
+/// The End's fan (`fan`): `pos.xz` of a rim vertex is its direction, scaled by the radius.
+const FAN: u32 = 5;
 
 /// The frame's sky (std140).
 #[repr(C)]
@@ -33,7 +35,7 @@ struct Uniform {
     color: [f32; 4],
     /// Sunset colour and alpha.
     sunrise: [f32; 4],
-    /// cos and sin of the sunset fan's turn, star brightness.
+    /// cos and sin of the sunset fan's turn, star brightness, the End fan's radius.
     sun: [f32; 4],
 }
 
@@ -77,6 +79,8 @@ pub fn inputs() -> horizon_shaders::GbuffersInputs {
          }} else if (hz_v_kind == {STAR}u) {{\n        \
              hz_p = (hz_sky_stars * vec4(hz_v_pos, 1.0)).xyz;\n        \
              hz_Color = vec4(hz_sky_sun.z);\n    \
+         }} else if (hz_v_kind == {FAN}u) {{\n        \
+             hz_p = vec3(hz_v_pos.x * hz_sky_sun.w, hz_v_pos.y, hz_v_pos.z * hz_sky_sun.w);\n    \
          }} else if (hz_v_kind == {VOID}u) {{\n        \
              hz_Color = vec4(0.0, 0.0, 0.0, 1.0);\n    \
          }}\n    \
@@ -188,14 +192,37 @@ fn horizon(out: &mut Vec<Vertex>) {
     }
 }
 
+/// The fan a pack's `gbuffers_skybasic` draws in the End while the dragon fight's fog leaves out
+/// vanilla's sky (`super::end_fog_sky`): from (0, -16, 0) under the eye to eight rim vertices 16
+/// above it, every 45° from +Z, at the render distance (the `far` uniform; scaled in the vertex
+/// stage). Fitted to the `gl_Vertex` our probe packs' fragments read in Iris 1.11.7 at render
+/// distances 12 and 8: 289 of 291 samples lie within 0.05 block of these eight planes (one of
+/// the other two, checked, sat on a terrain edge), and nothing drew above the rim.
+fn fan(out: &mut Vec<Vertex>) {
+    let rim = |i: i32| {
+        let a = (i as f32 * 45.0).to_radians();
+        Vertex {
+            pos: [a.sin(), 16.0, a.cos()],
+            kind: FAN,
+        }
+    };
+    let apex = Vertex {
+        pos: [0.0, -16.0, 0.0],
+        kind: FAN,
+    };
+    for i in 0..8 {
+        out.extend([apex, rim(i), rim(i + 1)]);
+    }
+}
+
 pub(super) struct PackSky {
     vertices: wgpu::Buffer,
     celestial: wgpu::Buffer,
     uniform: wgpu::Buffer,
     pub layout: wgpu::BindGroupLayout,
     group: wgpu::BindGroup,
-    /// Vertex ranges of the sky disc, the sunset fan, the stars and the void.
-    ranges: [Range<u32>; 4],
+    /// Vertex ranges of the sky disc, the sunset fan, the stars, the void and the End's fan.
+    ranges: [Range<u32>; 5],
 }
 
 impl PackSky {
@@ -227,6 +254,8 @@ impl PackSky {
         let stars = sunset.end..v.len() as u32;
         disc(-4.0, VOID, &mut v);
         let void = stars.end..v.len() as u32;
+        fan(&mut v);
+        let end_fan = void.end..v.len() as u32;
         let vertices = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
             label: Some("Shader pack sky"),
             contents: bytemuck::cast_slice(&v),
@@ -271,7 +300,7 @@ impl PackSky {
             uniform,
             layout,
             group,
-            ranges: [sky, sunset, stars, void],
+            ranges: [sky, sunset, stars, void, end_fan],
         }
     }
 
@@ -294,7 +323,8 @@ impl PackSky {
     /// Writes the frame's sky and returns its draws in vanilla's order: the disc, the sunset
     /// fan while the sun is near the horizon, the sun and the moon, the stars and, with the
     /// camera low, the void. `tilt` is the pack's `sunPathRotation` (degrees): the sun, moon
-    /// and stars turn with it (7.1).
+    /// and stars turn with it (7.1). In the End under the dragon fight's fog, only the End's fan,
+    /// in the fog colour (`fogColor`), as stage SKY.
     pub fn prepare(&self, queue: &wgpu::Queue, frame: &super::Frame, tilt: f32) -> Vec<Part> {
         let turn = super::pack_uniforms::tilt_matrix(tilt);
         let sun_angle = frame.sky.sun_angle.to_radians();
@@ -302,12 +332,22 @@ impl PackSky {
         let flip = if sun_angle.sin() < 0.0 { 180f32 } else { 0.0 };
         let theta = (flip + 90.0).to_radians();
         let (rotation, brightness) = frame.stars.unwrap_or_default();
-        let [r, g, b] = frame.sky.sky_color;
+        let end_fan = super::end_fog_sky(frame);
+        let [r, g, b] = match &frame.fog {
+            Some(f) if end_fan => [f.color[0], f.color[1], f.color[2]],
+            None if end_fan => frame.sky.fog_color,
+            _ => frame.sky.sky_color,
+        };
         let uniform = Uniform {
             stars: (turn * rotation).to_cols_array_2d(),
             color: [r, g, b, 1.0],
             sunrise: frame.sky.sunrise_color,
-            sun: [theta.cos(), theta.sin(), brightness.clamp(0.0, 1.0), 0.0],
+            sun: [
+                theta.cos(),
+                theta.sin(),
+                brightness.clamp(0.0, 1.0),
+                frame.detail_distance,
+            ],
         };
         queue.write_buffer(&self.uniform, 0, bytemuck::bytes_of(&uniform));
         // The sun's quad, then the moon's (Game::celestial_geometry), as triangles.
@@ -327,12 +367,15 @@ impl PackSky {
             })
             .collect();
         queue.write_buffer(&self.celestial, 0, bytemuck::cast_slice(&triangles));
-        let [sky, sunset, stars, void] = self.ranges.clone();
+        let [sky, sunset, stars, void, fan] = self.ranges.clone();
         let part = |stage, textured, range| Part {
             stage,
             textured,
             range,
         };
+        if end_fan {
+            return vec![part("SKY", false, fan)];
+        }
         let mut parts = vec![part("SKY", false, sky)];
         if frame.sky.sunrise_color[3] > 0.001 {
             parts.push(part("SUNSET", false, sunset));

crates/horizon-client-render/src/gfx/pack_uniforms.rs

@@ -709,6 +709,16 @@ fn smooth(value: f32, target: f32, half_life: f32, dt: f32) -> f32 {
 }
 
 impl FrameUniforms {
+    /// Forgets the frames before (the previous camera, smoothed values, the clock and the
+    /// centre depth), keeping the pack's atlas size and shadow settings.
+    pub(super) fn reset_history(&mut self) {
+        *self = Self {
+            atlas: self.atlas,
+            shadow: std::mem::take(&mut self.shadow),
+            ..Self::default()
+        };
+    }
+
     /// This frame's values for a render size of `size` pixels.
     pub fn update(&mut self, frame: &Frame, inputs: &PackInputs, size: [u32; 2]) {
         let now = std::time::Instant::now();
@@ -2367,6 +2377,61 @@ pub(super) mod initial_history_tests {
         assert_eq!((sixty.elapsed, sixty.delta), (1.0, 1.0 / 60.0));
     }
 
+    /// A reset pack draws its next frame as its first: no previous camera, smoothed values
+    /// at their targets, the clock from 0; the atlas size it was given stays.
+    #[test]
+    fn a_reset_forgets_the_uniforms_history_and_keeps_the_pack_s_settings() {
+        let hud = HudBatch::new([16, 16]);
+        let mut f = frame(&hud);
+        let mut uniforms = FrameUniforms {
+            atlas: [256, 128],
+            ..Default::default()
+        };
+        let mut inputs = PackInputs {
+            rain: 1.0,
+            eye_light: [15, 15],
+            frame_timing: Some(FrameTiming {
+                counter: 800,
+                elapsed: 99.0,
+                delta: 1.0,
+            }),
+            ..Default::default()
+        };
+        uniforms.center_depth_raw = Some(0.25);
+        uniforms.update(&f, &inputs, [16, 16]);
+        f.camera = glam::DVec3::new(7.0, 12.0, -30.0);
+        f.yaw = 77.0;
+        inputs.rain = 0.25;
+        inputs.eye_light = [3, 8];
+        inputs.frame_timing = None;
+        uniforms.reset_history();
+        uniforms.update(&f, &inputs, [16, 16]);
+        let float = |name| match uniforms.values[index(name).unwrap()] {
+            Value::F(v) => v,
+            _ => panic!("float uniform expected"),
+        };
+        let int = |name| match uniforms.values[index(name).unwrap()] {
+            Value::I(v) => v,
+            _ => panic!("integer uniform expected"),
+        };
+        assert_eq!(int("frameCounter")[0], 0);
+        assert_eq!(float("frameTime")[0], 0.0);
+        assert_eq!(int("atlasSize")[..2], [256, 128]);
+        assert_eq!(float("wetness")[0], 0.25);
+        assert_eq!(int("eyeBrightnessSmooth")[..2], [48, 128]);
+        assert_eq!(float("centerDepthSmooth")[0], 1.0);
+        for (previous, current) in [
+            ("previousCameraPosition", "cameraPosition"),
+            ("gbufferPreviousModelView", "gbufferModelView"),
+            ("gbufferPreviousProjection", "gbufferProjection"),
+        ] {
+            assert_eq!(
+                float(previous).map(f32::to_bits),
+                float(current).map(f32::to_bits)
+            );
+        }
+    }
+
     /// Iris 1.11.7 (probe pack): `ambientLight` is the dimension type's (0.1 in the Nether,
     /// 0.25 in the End), and `playerMood` and `constantMood` both the cave mood.
     #[test]
@@ -2411,6 +2476,7 @@ pub(super) mod initial_history_tests {
             skybox: false,
             end_sky: false,
             end_sky_sprite: None,
+            boss_world_fog: false,
             environment_fog: None,
             water_fog: [0.0; 3],
             fog: None,

crates/horizon-client-render/src/gfx/readback.rs

@@ -324,8 +324,9 @@ mod tests {
         reaches_an_8_bit_swapchain(&device, &queue, unorm, color, [0, 51, 255, 255]);
     }
 
-    /// `Rgba16Float`, the frame of a shader API 0.2 pack under `HORIZON_HDR_FRAME=float`
-    /// (`Renderer::frame_format`): what the tonemap left over 1 is clipped on the way.
+    /// `Rgba16Float`, the frame of a shader API 0.2 pack, or of HDR on without a pack, under
+    /// `HORIZON_HDR_FRAME=float` (`Renderer::frame_format`): what is left over 1 is clipped on
+    /// the way.
     #[test]
     fn a_float_frame_reaches_an_8_bit_swapchain() {
         let instance = crate::gfx::test_gpu::instance();

crates/horizon-client-render/src/gfx/terrain_model.rs

@@ -0,0 +1,66 @@
+//! Opaque/cutout terrain-sheet native models, with ordinary culling and depth writes.
+pub(super) fn pipelines(
+    device: &wgpu::Device,
+    layout: Option<&wgpu::PipelineLayout>,
+    shader: &wgpu::ShaderModule,
+    format: wgpu::TextureFormat,
+    sprite_constants: &[(&str, f64)],
+) -> [wgpu::RenderPipeline; 3] {
+    std::array::from_fn(|i| {
+        let mut constants = sprite_constants.to_vec();
+        constants.push(("NATIVE_MODEL_ALPHA_CUTOFF", [0.0, 0.1, 0.5][i]));
+        // The ordinary Vertex ABI is unchanged. This material's private payload uses
+        // normal's four bytes for a float z, and glint UV for float normal x/y.
+        let attributes = wgpu::vertex_attr_array![0=>Float32x3,1=>Float32x2,2=>Uint32,3=>Unorm8x4,4=>Uint8x4,5=>Uint32,6=>Float32x2];
+        device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
+            label: Some(
+                [
+                    "Native model solid",
+                    "Native model cutout",
+                    "Native model cutout mipmapped",
+                ][i],
+            ),
+            layout,
+            vertex: wgpu::VertexState {
+                module: shader,
+                entry_point: Some("vs_native_model"),
+                compilation_options: wgpu::PipelineCompilationOptions {
+                    constants: &constants,
+                    ..Default::default()
+                },
+                buffers: &[Some(wgpu::VertexBufferLayout {
+                    array_stride: std::mem::size_of::<super::Vertex>() as u64,
+                    step_mode: wgpu::VertexStepMode::Vertex,
+                    attributes: &attributes,
+                })],
+            },
+            primitive: wgpu::PrimitiveState {
+                cull_mode: Some(wgpu::Face::Back),
+                ..Default::default()
+            },
+            depth_stencil: Some(wgpu::DepthStencilState {
+                format: wgpu::TextureFormat::Depth32Float,
+                depth_write_enabled: Some(true),
+                depth_compare: Some(wgpu::CompareFunction::GreaterEqual),
+                stencil: Default::default(),
+                bias: Default::default(),
+            }),
+            multisample: Default::default(),
+            fragment: Some(wgpu::FragmentState {
+                module: shader,
+                entry_point: Some("fs_native_model"),
+                compilation_options: wgpu::PipelineCompilationOptions {
+                    constants: &constants,
+                    ..Default::default()
+                },
+                targets: &[Some(wgpu::ColorTargetState {
+                    format,
+                    blend: None,
+                    write_mask: wgpu::ColorWrites::ALL,
+                })],
+            }),
+            multiview_mask: None,
+            cache: None,
+        })
+    })
+}

crates/horizon-client-render/src/gfx/world_post.rs

@@ -257,14 +257,23 @@ impl Post {
 
     /// The world's rendered size and the size it is shown at (TAA's history).
     fn sizes(&self, window: [u32; 2]) -> ([u32; 2], [u32; 2]) {
-        let output = window.map(|v| ((v as f32 * self.scale).round() as u32).clamp(1, 8192));
         let upscale = if self.taa_on { self.upscale } else { 1.0 };
+        self.sizes_with_upscale(window, upscale)
+    }
+
+    fn sizes_with_upscale(&self, window: [u32; 2], upscale: f32) -> ([u32; 2], [u32; 2]) {
+        let output = window.map(|v| ((v as f32 * self.scale).round() as u32).clamp(1, 8192));
         (
             output.map(|v| ((v as f32 / upscale).round() as u32).max(1)),
             output,
         )
     }
 
+    /// The next TAA frame's input size, even before its first jitter or resize.
+    pub(super) fn taa_render_size(&self, window: [u32; 2]) -> [u32; 2] {
+        self.sizes_with_upscale(window, self.upscale).0
+    }
+
     /// TAA's sub-pixel jitter this frame, as a clip-space matrix to multiply into the
     /// world's projection (identity while `on` is false); `view_proj` is the unjittered
     /// projection, relative to `camera`. Call it before `prepare`, once per frame.
@@ -604,7 +613,7 @@ mod tests {
 
     #[test]
     fn jitter_stays_inside_the_pixel() {
-        for i in 1..=8 {
+        for i in 1..=128 {
             let (x, y) = (halton(i, 2), halton(i, 3));
             assert!((0.0..1.0).contains(&x) && (0.0..1.0).contains(&y));
         }
@@ -614,6 +623,30 @@ mod tests {
         );
     }
 
+    #[test]
+    fn culling_uses_the_next_taa_size_before_the_first_jitter_or_resize() {
+        let Some((device, _)) = test_device() else {
+            return;
+        };
+        let mut post = Post::new(&device, wgpu::TextureFormat::Rgba8Unorm);
+        assert!(!post.taa_on);
+        assert!(post.size().is_none());
+        for (window, scale, upscale, expected) in [
+            ([1280, 720], 1.0, 1.0, [1280, 720]),
+            ([1281, 721], 0.5, 2.0, [321, 181]),
+            ([3840, 2160], 0.25, 4.0, [240, 135]),
+            ([10000, 10000], 2.0, 4.0, [2048, 2048]),
+            ([0, 0], 0.5, 4.0, [1, 1]),
+        ] {
+            post.scale = scale;
+            post.upscale = upscale;
+            post.taa_on = false;
+            assert_eq!(post.taa_render_size(window), expected);
+            post.taa_on = true;
+            assert_eq!(post.sizes(window).0, expected);
+        }
+    }
+
     fn test_device() -> Option<(wgpu::Device, wgpu::Queue)> {
         let instance = crate::gfx::test_gpu::instance();
         let adapter = pollster::block_on(instance.request_adapter(&Default::default())).ok()?;

crates/horizon-client-render/src/graphics.rs

@@ -1092,8 +1092,9 @@ impl Graphics {
         // (horizon_threads: niced on Linux; on macOS and Windows the server
         // and render threads are raised above four cores, where vanilla
         // raises its server thread). Leaving two idled a core of a 4-thread
-        // laptop while a world loaded: a teleport there took ~15% longer.
-        let auto = horizon_threads::worker_count().saturating_sub(1).max(1);
+        // laptop while a world loaded: a teleport there took ~15% longer. On Apple
+        // silicon only the performance cores count (horizon_threads::default_workers).
+        let auto = horizon_threads::jobs::default_threads();
         if self.battery { auto.div_ceil(2) } else { auto }
     }
     /// The frame cap battery mode adds: 60 in a world, 30 in menus without a
@@ -1476,7 +1477,10 @@ mod tests {
         let g = Graphics::default();
         assert_eq!(g.workers, 0);
         let cores = horizon_threads::worker_count();
-        assert_eq!(g.worker_threads(), cores.saturating_sub(1).max(1));
+        assert!((1..=cores.saturating_sub(1).max(1)).contains(&g.worker_threads()));
+        if !cfg!(target_vendor = "apple") {
+            assert_eq!(g.worker_threads(), cores.saturating_sub(1).max(1));
+        }
         // A manual count is the player's own choice, kept as asked.
         let manual = Graphics { workers: 3, ..g };
         assert_eq!(manual.worker_threads(), 3);

crates/horizon-client-render/src/graphics_ui.rs

@@ -1663,6 +1663,7 @@ impl GraphicsUi {
             hover,
             focused,
             held: self.dragging == Some(item),
+            key: None,
         };
         shell::row(batch, atlas, cols, y, &view);
     }

crates/horizon-client-render/src/hdr.wgsl

@@ -61,9 +61,10 @@ fn shows_world(c: vec3<f32>, w: vec3<f32>) -> bool {
 // A texel with its alpha as an 8-bit frame holds it. A 16-bit frame
 // (Renderer::frame_format) keeps alpha between 8-bit steps, where the marks below
 // would read differently (an alpha of 0.001 would count as the hand); its colour
-// keeps the gradients 8 bits would band. On an 8-bit frame nothing changes.
+// keeps the gradients 8 bits would band, and a float frame's (LINEAR_FRAME) the
+// light over 1 that blends added past white. On an 8-bit frame nothing changes.
 fn frame_texel(v: vec4<f32>) -> vec4<f32> {
-    return vec4(saturate(v.rgb), round(saturate(v.a) * 255.0) / 255.0);
+    return vec4(max(v.rgb, vec3(0.0)), round(saturate(v.a) * 255.0) / 255.0);
 }
 
 // Linear BT.709 to BT.2020 (ITU-R BT.2087), columns first.
@@ -161,15 +162,12 @@ fn calibration_nits(p: vec2<f32>, size: vec2<f32>) -> f32 {
         return vec4(nits / 80.0, 1.0);
     }
     let f = frame_texel(textureLoad(frame, at, 0));
-    let c = f.rgb;
     // What covers the world here (Hdr::keep_world): nothing at 0, the hand at
     // 1/255 (Hdr::mark_hand: drawn at the world's brightness), else the HUD or a
     // menu, by how much.
     let covered = f.a > 0.0;
     let hand = covered && f.a < 1.5 / 255.0;
     let ui = select(f.a, 0.0, hand);
-    // Gamma 2.2, as SDR displays and the compositors' SDR paths decode it.
-    var light = pow(max(c, vec3(0.0)), vec3(2.2));
     let w = frame_texel(textureLoad(world, at, 0));
     // The world's alpha is below 0.75 on light sources, the sun and the moon
     // (terrain.wgsl, entity.wgsl): only those shine, and only where nothing was
@@ -179,11 +177,19 @@ fn calibration_nits(p: vec2<f32>, size: vec2<f32>) -> f32 {
     // writes its own alpha there (Hdr::hand_light_view): 1, or a light source it holds.
     var lifted = false;
     let shows = params.world > 0.5 && params.peak > 1.0
-        && (hand || (!covered && shows_world(c, w.rgb)));
+        && (hand || (!covered && shows_world(f.rgb, w.rgb)));
+    // Light over 1 (a float frame's) shows only where the world does and carries
+    // no mark (alpha 1), up to the peak: light written as light. Marked pixels clip
+    // at white before their lift, as on a unorm frame, so light sources, the sun and
+    // HDR lighting look as they do there; so do the HUD, menus and HDR Lighting off.
+    let c = select(min(f.rgb, vec3(1.0)), f.rgb, shows && w.a == 1.0);
+    // Gamma 2.2, as SDR displays and the compositors' SDR paths decode it.
+    var light = pow(c, vec3(2.2));
     // HDR lighting: alpha between 0.76 and 1 is how much of it the surface gets. Vanilla's
     // light is albedo times lightmap, so this is the lightmap going past 1. It eases into the
-    // peak from 60% of it, so bright textures keep their detail.
-    if shows && w.a >= 0.75 {
+    // peak from 60% of it, so bright textures keep their detail. Unmarked light (alpha 1)
+    // gets no gain and no knee: the clamp to the peak below is all it needs here.
+    if shows && w.a >= 0.75 && w.a < 1.0 {
         let top = max(light.r, max(light.g, light.b));
         let gain = 1.0 + (params.scene - 1.0) * (1.0 - w.a) / 0.24;
         let v = top * gain;
@@ -214,6 +220,7 @@ fn calibration_nits(p: vec2<f32>, size: vec2<f32>) -> f32 {
             light = vec3(dot(light, vec3(0.2126, 0.7152, 0.0722)));
         }
     }
+    light = min(light, vec3(params.peak));
     // The HUD and menus at their own brightness, by how much they cover.
     light *= mix(1.0, params.ui, ui);
     let scrgb = light * params.paper;

crates/horizon-client-render/src/hud.rs

@@ -1333,6 +1333,36 @@ impl HudAtlas {
             }
         }
         if full {
+            // Official Recipes artwork from Just Enough Items, under MIT.
+            for (name, png) in [
+                (
+                    "button_enabled_v2",
+                    include_bytes!("jei_recipes/button_enabled_v2.png").as_slice(),
+                ),
+                (
+                    "button_disabled_v2",
+                    include_bytes!("jei_recipes/button_disabled_v2.png").as_slice(),
+                ),
+                (
+                    "button_highlight_v2",
+                    include_bytes!("jei_recipes/button_highlight_v2.png").as_slice(),
+                ),
+                (
+                    "icons/arrow_previous_v2",
+                    include_bytes!("jei_recipes/icons/arrow_previous_v2.png").as_slice(),
+                ),
+                (
+                    "icons/arrow_next_v2",
+                    include_bytes!("jei_recipes/icons/arrow_next_v2.png").as_slice(),
+                ),
+                (
+                    "search_background_v2",
+                    include_bytes!("jei_recipes/search_background_v2.png").as_slice(),
+                ),
+            ] {
+                let (width, height, rgba) = decode_bytes(png)?;
+                images.push((format!("horizon/jei/{name}"), width, height, rgba));
+            }
             Self::slots(&mut images, crate::trims::slot_size(root), mod_image);
             // MissingTextureAtlasSprite.generateMissingImage: 16x16, magenta
             // and black quarters.
@@ -1354,6 +1384,11 @@ impl HudAtlas {
                 bordered.insert(image.0.clone());
             }
         }
+        if full {
+            let (width, height, rgba) =
+                decode_bytes(include_bytes!("jei_recipes/config_button.png"))?;
+            images.push(("horizon/recipes/settings".to_owned(), width, height, rgba));
+        }
         images.sort_by(|a, b| b.2.cmp(&a.2).then(b.1.cmp(&a.1)));
         let (width, placements, glyph_region) =
             Self::layout_leaving_out(&mut images, &mut animated, &cit_names, MAX_ATLAS_SIZE)?;

crates/horizon-client-render/src/hud_overlays.rs

@@ -115,8 +115,7 @@ impl From<&crate::effects::EffectInstance> for EffectIcon {
             color: def.map_or(0, |d| d.color as i32),
             ambient: effect.ambient,
             duration: effect.duration,
-            // Horizon keeps no showIcon flag: every effect shows its icon.
-            show_icon: true,
+            show_icon: effect.show_icon,
         }
     }
 }

crates/horizon-client-render/src/jei_recipes/LICENSE.txt

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2014-2015 mezz
+
+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.

crates/horizon-client-render/src/lib.rs

@@ -36,12 +36,15 @@ pub mod connected;
 pub mod containers;
 pub mod controller_ui;
 pub mod crash;
+pub mod custom_sky;
 pub mod datapack;
 pub mod dynamic_light;
 pub mod effects;
 pub mod environment;
 pub mod extras;
+pub(crate) mod extras_ui;
 pub mod fast_hash;
+pub mod fluid_render;
 pub mod fog;
 pub mod font;
 pub mod fusion;
@@ -56,6 +59,7 @@ pub mod hud_overlays;
 pub mod inventory_effects;
 pub mod java_text;
 pub mod jigsaw_block;
+pub mod terrain_model;
 pub use horizon_world::json_folder;
 pub mod level_loading;
 pub mod light;

crates/horizon-client-render/src/mesher.rs

@@ -90,6 +90,11 @@ fn round_to_u16(v: f32) -> u16 {
 }
 /// Fixed-point steps per unit of `TerrainVertex` UVs, which span `[0, 2)`.
 pub const UV_STEPS: f32 = 32768.0;
+/// A model quad's own UVs in `TerrainVertex` fixed point, the packing
+/// `TerrainVertex::new` does, baked once per face (`BakedFace::uv_fixed`).
+pub(crate) fn baked_uv(uv: [[f32; 2]; 4]) -> [[u16; 2]; 4] {
+    uv.map(|uv| uv.map(|v| round_to_u16(v * UV_STEPS)))
+}
 /// Fixed-point steps per block of distant-terrain UVs (`TerrainVertex::tiled`),
 /// which span `[0, 2048)`: merged faces repeat their sprite once per block.
 pub const TILED_UV_STEPS: f32 = 32.0;
@@ -103,6 +108,23 @@ impl TerrainVertex {
             color,
         }
     }
+    /// A vertex whose UV is already in `UV_STEPS` fixed point (a model face's
+    /// own UVs, baked in `BakedFace::uv_fixed`).
+    pub(crate) fn packed_uv(
+        pos: [f32; 3],
+        uv: [u16; 2],
+        layer: u16,
+        color: u32,
+        light: u16,
+    ) -> Self {
+        Self {
+            pos,
+            uv,
+            layer,
+            light,
+            color,
+        }
+    }
     /// A vertex of a merged distant-terrain face, its UV in blocks from the
     /// face's corner. Drawn with an instance UV scale of `1 / TILED_UV_STEPS`.
     pub fn tiled(pos: [f32; 3], uv: [f32; 2], layer: u16, color: u32, light: u16) -> Self {
@@ -122,6 +144,63 @@ impl TerrainVertex {
 #[cfg(test)]
 mod vertex_tests {
     use super::TerrainVertex;
+
+    #[test]
+    fn baked_face_keeps_shape_bounds_and_fixed_point_uvs() {
+        use crate::models::catalog::BakedFace;
+        use horizon_assets::{
+            bake::ModelQuad,
+            model::{Direction, Material},
+        };
+
+        let face = BakedFace::new(
+            ModelQuad {
+                positions: [
+                    [-0.25, 0.5, 0.125],
+                    [-0.25, 0.5, 0.875],
+                    [0.625, 0.5, 0.875],
+                    [0.625, 0.5, 0.125],
+                ],
+                uv: [
+                    [-0.25, f32::NAN],
+                    [1.0 / 65536.0, 3.0 / 65536.0],
+                    [1.5, 2.0],
+                    [f32::INFINITY, f32::NEG_INFINITY],
+                ],
+                facing: Direction::Up,
+                cull: None,
+                material: Material {
+                    sprite: "test:face".into(),
+                    force_translucent: false,
+                },
+                tint_index: -1,
+                shade_direction_override: None,
+                light_emission: 0,
+                light: [0; 2],
+                color: None,
+                ambient_occlusion: None,
+                render_type: None,
+                shade: true,
+            },
+            0,
+            true,
+            false,
+            None,
+        );
+        // Literal expectations: axis-ordered extrema and complements, plus
+        // clamping and half-step rounding in 1/32768 UV units.
+        let bounds: [f32; 12] = [
+            0.5, 0.5, 0.125, 0.875, -0.25, 0.625, 0.5, 0.5, 0.875, 0.125, 1.25, 0.375,
+        ];
+        for shape in face.shapes {
+            assert_eq!(shape.bounds.map(f32::to_bits), bounds.map(f32::to_bits));
+            assert!(shape.partial);
+        }
+        assert!(!face.shapes[0].cubic);
+        assert!(face.shapes[1].cubic);
+        assert_eq!(face.uv_fixed, [[0, 0], [1, 2], [49152, 65535], [65535, 0]]);
+    }
+
     #[test]
     fn model_uvs_pack_exactly() {
         for i in 0..=32 {
@@ -957,6 +1036,12 @@ const P: usize = 16 + 2 * B as usize;
 fn pi(x: i32, y: i32, z: i32) -> usize {
     ((y + B) as usize * P + (z + B) as usize) * P + (x + B) as usize
 }
+/// `pi`'s index offset of a step `n`: `pi(p + n) - pi(p)`, so the samples
+/// around a cell are `base + step_index(n)` rather than another `pi`.
+#[inline]
+const fn step_index(n: [i32; 3]) -> isize {
+    (n[0] + P as i32 * n[2] + (P * P) as i32 * n[1]) as isize
+}
 /// Blocks and light of one section plus a `B`-block border.
 #[derive(Default)]
 struct Padded {
@@ -1079,6 +1164,17 @@ const DIRECTIONS: [(Direction, [i32; 3], u8); 6] = [
 const fn direction_info(d: Direction) -> (Direction, [i32; 3], u8) {
     (d, d.normal(), d.opposite() as u8)
 }
+/// `step_index` of each direction's normal, indexed like `DIRECTIONS`: the
+/// padded index of a block's neighbour is its own plus one of these.
+const OFFSETS: [isize; 6] = {
+    let mut out = [0isize; 6];
+    let mut i = 0;
+    while i < 6 {
+        out[i] = step_index(DIRECTIONS[i].1);
+        i += 1;
+    }
+    out
+};
 /// Per-worker temporary arrays. They never hold resource-pack references or
 /// geometry still owned by the renderer, and total about 150 KiB per worker
 /// (the leaf mask adds 8,000 cells, depths and a queue).
@@ -1540,8 +1636,12 @@ impl Mesher<'_> {
         let mut models = Vec::new();
         for y in 0..16 {
             for z in 0..16 {
+                // The padded index of the row's x = 0 cell: `pi(x, y, z)` is
+                // `row + x` and a neighbour adds `OFFSETS[d]`.
+                let row = pi(0, y, z);
                 for x in 0..16 {
-                    let id = pad.blocks[pi(x, y, z)];
+                    let cell = row + x as usize;
+                    let id = pad.blocks[cell];
                     if id == 0 {
                         continue;
                     }
@@ -1596,7 +1696,7 @@ impl Mesher<'_> {
                         && self.leaf_culling.is_interior()
                         && scratch.leaf.interior(self.leaf_culling, x, y, z);
                     for (d, [dx, dy, dz], opposite) in DIRECTIONS {
-                        let neighbor = pad.blocks[pi(x + dx, y + dy, z + dz)];
+                        let neighbor = pad.blocks[(cell as isize + OFFSETS[d as usize]) as usize];
                         // `should_render_face`'s first test, without its lookups: a
                         // full occlusion face toward this block hides the face.
                         if full_faces[neighbor as usize] >> opposite & 1 != 0 {
@@ -1656,7 +1756,8 @@ impl Mesher<'_> {
                                 let on_edge = p.iter().all(|v| (v[1] - plane).abs() < 1e-4);
                                 let centre =
                                     [0, 2].map(|k| p.iter().map(|v| v[k]).sum::<f32>() / 4.0);
-                                let other = pad.blocks[pi(x, y + dy, z)];
+                                let other =
+                                    pad.blocks[(cell as isize + step_index([0, dy, 0])) as usize];
                                 if on_edge && connected.stacked_pane_hides(id, other, centre) {
                                     continue;
                                 }
@@ -1666,6 +1767,7 @@ impl Mesher<'_> {
                                 &mut tints,
                                 &mut out,
                                 [x, y, z],
+                                cell,
                                 origin,
                                 face,
                                 ao,
@@ -1706,6 +1808,7 @@ impl Mesher<'_> {
         tints: &mut Tints,
         out: &mut SectionMesh,
         pos: [i32; 3],
+        cell: usize,
         origin: [f32; 3],
         face: &BakedFace,
         ao: bool,
@@ -1730,11 +1833,14 @@ impl Mesher<'_> {
         } else {
             lighting::cardinal(self.nether_shading, shade_face)
         };
+        // The quad's shape (bounds, partial, cubic), baked per face for full and
+        // non-full blocks: a pure function of the quad and the block's `full`.
+        let shape = &face.shapes[usize::from(state.full)];
         // Grey level per vertex before tinting, vanilla light coords, and ambient occlusion factor.
         let (gray, coords, ao_factor) = if ao {
             let info = &self.tables.info;
             let (brightness, coords) =
-                lighting::ambient_occlusion(pad, info, state, pos, &q.positions, q.facing);
+                lighting::ambient_occlusion(pad, info, state, pos, shape, q.facing);
             let gray = if self.separate_ao {
                 [lighting::gray(directional); 4]
             } else {
@@ -1744,7 +1850,7 @@ impl Mesher<'_> {
         } else {
             let coords = match q.cull {
                 Some(d) => lighting::coords(pad, state, lighting::step(pos, d)),
-                None => lighting::flat(pad, state, pos, &q.positions, q.facing),
+                None => lighting::flat_shaped(pad, state, pos, q.facing, shape),
             };
             ([lighting::gray(directional); 4], [coords; 4], [1.0f32; 4])
         };
@@ -1768,8 +1874,7 @@ impl Mesher<'_> {
                 count += 1;
             }
         };
-        let neighbour =
-            |[dx, dy, dz]: [i32; 3]| pad.blocks[pi(pos[0] + dx, pos[1] + dy, pos[2] + dz)];
+        let neighbour = |n: [i32; 3]| pad.blocks[(cell as isize + step_index(n)) as usize];
         let fused = face.fusion.and_then(|rule| {
             fusion.pick(
                 rule,
@@ -1810,44 +1915,41 @@ impl Mesher<'_> {
                 &mut push,
             )
         };
+        let vertex = |tint: Option<u32>, i: usize, uv: [u16; 2]| {
+            let g = gray[i] as u32;
+            let rgb = match tint {
+                Some(t) => [16, 8, 0].map(|shift| g * (t >> shift & 255) / 255),
+                None => [g; 3],
+            };
+            let p = q.positions[i];
+            let color = if self.separate_ao {
+                let ao_byte = (ao_factor[i] * 255.0).round().clamp(0.0, 255.0) as u32;
+                ao_byte << 24 | (pack_rgb(rgb) & 0x00FF_FFFF)
+            } else {
+                emitting(pack_rgb(rgb), tier)
+            };
+            TerrainVertex::packed_uv(
+                [p[0] + origin[0], p[1] + origin[1], p[2] + origin[2]],
+                uv,
+                0,
+                color,
+                pack_coords(lighting::with_min(coords[i], q.light)),
+            )
+        };
         let vertices = |tint: Option<u32>, uv: [[f32; 2]; 4]| {
-            std::array::from_fn::<_, 4, _>(|i| {
-                let g = gray[i] as u32;
-                let rgb = match tint {
-                    Some(t) => [16, 8, 0].map(|shift| g * (t >> shift & 255) / 255),
-                    None => [g; 3],
-                };
-                let p = q.positions[i];
-                let color = if self.separate_ao {
-                    let ao_byte = (ao_factor[i] * 255.0).round().clamp(0.0, 255.0) as u32;
-                    ao_byte << 24 | (pack_rgb(rgb) & 0x00FF_FFFF)
-                } else {
-                    emitting(pack_rgb(rgb), tier)
-                };
-                (
-                    TerrainVertex::new(
-                        [p[0] + origin[0], p[1] + origin[1], p[2] + origin[2]],
-                        uv[i],
-                        0,
-                        color,
-                        pack_coords(lighting::with_min(coords[i], q.light)),
-                    ),
-                    uv[i],
-                )
-            })
+            let fixed = uv.map(|uv| uv.map(|v| round_to_u16(v * UV_STEPS)));
+            std::array::from_fn::<_, 4, _>(|i| (vertex(tint, i, fixed[i]), uv[i]))
         };
         // Vanilla's pane models mirror some faces' textures; OptiFine's don't, so a tile's borders
         // land where the neighbours are: on a pane, tiles take the cube's own UVs.
         let standard = || q.positions.map(|p| standard_uv(q.facing, p));
         let tiled = !matches!(pick, Pick::Keep);
-        let corners = vertices(
-            tint,
-            if state.pane && tiled {
-                standard()
-            } else {
-                q.uv
-            },
-        );
+        let corners = if state.pane && tiled {
+            vertices(tint, standard())
+        } else {
+            // The face's own UVs, already packed: no per-vertex rounding.
+            std::array::from_fn(|i| (vertex(tint, i, face.uv_fixed[i]), q.uv[i]))
+        };
         // Opaque leaves (forceOpaque) and leaves a leaf-culling mode proved internal draw in the
         // solid layer whatever their sprite.
         let solid_leaves = !self.cutout_leaves && state.leaves || interior_leaf;

crates/horizon-client-render/src/mesher/fluid.rs

@@ -19,6 +19,11 @@ use std::{convert::Infallible, sync::OnceLock};
 /// `FluidRenderer.MAX_FLUID_HEIGHT`.
 const MAX_HEIGHT: f32 = 0.888_888_9;
 const EPSILON: f32 = 0.001;
+/// `super::step_index` of the unit steps of the padded index: one block east
+/// (+x), one south (+z), one up (+y).
+const X_STEP: isize = 1;
+const P_STEP: isize = super::P as isize;
+const UP: isize = super::step_index([0, 1, 0]);
 
 /// For the occlusion face toward `direction`: the height from the bottom over
 /// which its slice flush with the `direction` side covers the whole width
@@ -224,14 +229,14 @@ pub(super) fn tesselate(
         }
     };
     let info = &tables.info;
-    let at = |p: [i32; 3]| &info[pad.blocks[pi(p[0], p[1], p[2])] as usize];
-    let me = at([x, y, z]);
+    // The cell's own padded index: every other cell sampled here is a constant
+    // step from it (`super::step_index`), so no `pi` per sample.
+    let cell = pi(x, y, z) as isize;
+    let at = |step: isize| &info[pad.blocks[(cell + step) as usize] as usize];
+    let me = at(0);
     let kind = me.fluid.kind();
     let same = |s: &Info| s.fluid.kind().same_family(kind);
-    let neighbor = |d: Direction| {
-        let [dx, dy, dz] = super::DIRECTIONS[d as usize].1;
-        at([x + dx, y + dy, z + dz])
-    };
+    let neighbor = |d: Direction| at(super::OFFSETS[d as usize]);
     let (down, up) = (neighbor(Direction::Down), neighbor(Direction::Up));
     let should_render = |d: Direction| !same(neighbor(d)) && !occluded_by_self(me, d);
     let render_up = !same(up);
@@ -265,10 +270,10 @@ pub(super) fn tesselate(
             crate::mesher::emitting(pack_rgb(rgb), emission)
         }
     };
-    let height = |p: [i32; 3]| -> f32 {
-        let s = at(p);
+    let height = |step: isize| -> f32 {
+        let s = at(step);
         if same(s) {
-            if same(at([p[0], p[1] + 1, p[2]])) {
+            if same(at(step + UP)) {
                 1.0
             } else {
                 s.fluid.own_height()
@@ -279,15 +284,15 @@ pub(super) fn tesselate(
             -1.0
         }
     };
-    let own = height([x, y, z]);
+    let own = height(0);
     let (mut ne, mut nw, mut se, mut sw) = (1.0f32, 1.0f32, 1.0f32, 1.0f32);
     if own < 1.0 {
-        let n = height([x, y, z - 1]);
-        let s = height([x, y, z + 1]);
-        let e = height([x + 1, y, z]);
-        let w = height([x - 1, y, z]);
+        let n = height(-P_STEP);
+        let s = height(P_STEP);
+        let e = height(X_STEP);
+        let w = height(-X_STEP);
         // calculateAverageHeight(self, height2, height1, corner)
-        let average = |h2: f32, h1: f32, corner: [i32; 3]| -> f32 {
+        let average = |h2: f32, h1: f32, corner: isize| -> f32 {
             if h1 >= 1.0 || h2 >= 1.0 {
                 return 1.0;
             }
@@ -313,16 +318,17 @@ pub(super) fn tesselate(
             add(h2);
             sum[0] / sum[1]
         };
-        ne = average(n, e, [x + 1, y, z - 1]);
-        nw = average(n, w, [x - 1, y, z - 1]);
-        se = average(s, e, [x + 1, y, z + 1]);
-        sw = average(s, w, [x - 1, y, z + 1]);
+        ne = average(n, e, X_STEP - P_STEP);
+        nw = average(n, w, -X_STEP - P_STEP);
+        se = average(s, e, X_STEP + P_STEP);
+        sw = average(s, w, -X_STEP + P_STEP);
     }
-    let light = |p: [i32; 3]| {
-        let above = [p[0], p[1] + 1, p[2]];
+    let light = |step: isize| {
+        let i = (cell + step) as usize;
+        let above = (cell + step + UP) as usize;
         pack_coords(lighting::max_coords(
-            lighting::coords(pad, at(p), p),
-            lighting::coords(pad, at(above), above),
+            lighting::coords_at(pad, lighting::state_at(pad, info, i), i),
+            lighting::coords_at(pad, lighting::state_at(pad, info, above), above),
         ))
     };
     let (still, flow, overlay) = if water {
@@ -393,7 +399,7 @@ pub(super) fn tesselate(
         // FluidState.shouldRenderBackwardUpFace over the 3x3 cells above.
         let backward = (-1..=1).any(|ox| {
             (-1..=1).any(|oz| {
-                let s = at([x + ox, y + 1, z + oz]);
+                let s = at(UP + ox as isize * X_STEP + oz as isize * P_STEP);
                 !same(s) && !s.solid
             })
         });
@@ -412,7 +418,7 @@ pub(super) fn tesselate(
             corners,
             layer,
             color(cardinal(D::Up)),
-            light([x, y, z]),
+            light(0),
             backward,
             Direction::Up as usize,
         );
@@ -428,12 +434,12 @@ pub(super) fn tesselate(
             ],
             still,
             color(cardinal(D::Down)),
-            light([x, y - 1, z]),
+            light(-UP),
             false,
             Direction::Down as usize,
         );
     }
-    let side_light = light([x, y, z]);
+    let side_light = light(0);
     let up_shade = cardinal(D::Up);
     for (i, d) in [
         Direction::North,

crates/horizon-client-render/src/mesher/lighting.rs

@@ -3,6 +3,7 @@
 //! and `ModelBlockRenderer`'s integer colour arithmetic (`ARGB.gray`,
 //! `scaleRGB`, `multiply`).
 use super::{Info, Padded, pi};
+use crate::models::catalog::QuadShape;
 use horizon_assets::model::Direction as D;
 
 /// `LightCoordsUtil.FULL_BRIGHT`.
@@ -25,28 +26,37 @@ pub(super) fn cardinal(nether: bool, face: D) -> f32 {
 pub(super) fn pack_flat(nether: bool) -> f32 {
     cardinal(nether, D::Up)
 }
+/// The normals of `D`'s variants, in the order [`ADJACENCY`] is indexed by.
+const NORMALS: [[i32; 3]; 6] = [
+    [0, -1, 0],
+    [0, 1, 0],
+    [0, 0, -1],
+    [0, 0, 1],
+    [-1, 0, 0],
+    [1, 0, 0],
+];
 fn normal(face: D) -> [i32; 3] {
-    match face {
-        D::Down => [0, -1, 0],
-        D::Up => [0, 1, 0],
-        D::North => [0, 0, -1],
-        D::South => [0, 0, 1],
-        D::West => [-1, 0, 0],
-        D::East => [1, 0, 0],
-    }
+    NORMALS[face as usize]
 }
 pub(super) fn step(p: [i32; 3], face: D) -> [i32; 3] {
     let n = normal(face);
     [p[0] + n[0], p[1] + n[1], p[2] + n[2]]
 }
-fn state<'a>(pad: &Padded, info: &'a [Info], p: [i32; 3]) -> &'a Info {
-    &info[pad.blocks[pi(p[0], p[1], p[2])] as usize]
+/// The block state of the padded cell at index `i` (see `pi`, `step_index`).
+#[inline]
+pub(super) fn state_at<'a>(pad: &Padded, info: &'a [Info], i: usize) -> &'a Info {
+    &info[pad.blocks[i] as usize]
 }
 /// `LightCoordsUtil.getLightCoords`: light at `p` as seen through `state`
 /// (block level << 4 | sky level << 20).
 pub(super) fn coords(pad: &Padded, state: &Info, p: [i32; 3]) -> u32 {
     packed_coords(state, pad.light[pi(p[0], p[1], p[2])])
 }
+/// `coords` of the cell at index `i`, as seen through `state`.
+#[inline]
+pub(super) fn coords_at(pad: &Padded, state: &Info, i: usize) -> u32 {
+    packed_coords(state, pad.light[i])
+}
 /// `coords` of a stored light byte (sky level << 4 | block level).
 pub(super) fn packed_coords(state: &Info, packed: u8) -> u32 {
     if state.emissive {
@@ -238,64 +248,21 @@ const ADJACENCY: [Adjacency; 6] = [
     adjacency(D::West),
     adjacency(D::East),
 ];
-/// `prepareQuadShape`: the quad's bounds, whether it is partial (smaller than
-/// the block face) and whether it is cubic (flush with the block boundary, or
-/// flat on a full collision shape).
-struct Shape {
-    bounds: [f32; 12],
-    partial: bool,
-    cubic: bool,
-}
-fn shape(positions: &[[f32; 3]; 4], face: D, full: bool) -> Shape {
-    let (mut min, mut max) = ([32f32; 3], [-32f32; 3]);
-    for p in positions {
-        for i in 0..3 {
-            min[i] = min[i].min(p[i]);
-            max[i] = max[i].max(p[i]);
-        }
-    }
-    let mut bounds = [0f32; 12];
-    for (index, value) in [
-        (WEST, min[0]),
-        (EAST, max[0]),
-        (DOWN, min[1]),
-        (UP, max[1]),
-        (NORTH, min[2]),
-        (SOUTH, max[2]),
-    ] {
-        bounds[index as usize] = value;
-        bounds[index as usize + 6] = 1.0 - value;
-    }
-    let (lo, hi) = (1.0e-4f32, 0.9999f32);
-    let partial = |a: usize, b: usize| min[a] >= lo || min[b] >= lo || max[a] <= hi || max[b] <= hi;
-    let (partial, cubic) = match face {
-        D::Down => (partial(0, 2), min[1] == max[1] && (min[1] < lo || full)),
-        D::Up => (partial(0, 2), min[1] == max[1] && (max[1] > hi || full)),
-        D::North => (partial(0, 1), min[2] == max[2] && (min[2] < lo || full)),
-        D::South => (partial(0, 1), min[2] == max[2] && (max[2] > hi || full)),
-        D::West => (partial(1, 2), min[0] == max[0] && (min[0] < lo || full)),
-        D::East => (partial(1, 2), min[0] == max[0] && (max[0] > hi || full)),
-    };
-    Shape {
-        bounds,
-        partial,
-        cubic,
-    }
+fn shape(positions: &[[f32; 3]; 4], face: D, full: bool) -> QuadShape {
+    QuadShape::new(positions, face, full)
 }
 /// `prepareQuadFlat` for a quad without a cull face: light from the
-/// neighbour when the quad is flush with the face, else from the block itself.
-pub(super) fn flat(
+/// neighbour when the quad is flush with the face (cubic), else from the block
+/// itself. `shape` is the quad's baked [`QuadShape`].
+pub(super) fn flat_shaped(
     pad: &Padded,
     own: &Info,
     pos: [i32; 3],
-    positions: &[[f32; 3]; 4],
     face: D,
+    shape: &QuadShape,
 ) -> u32 {
-    coords(
-        pad,
-        own,
-        flat_position(pos, positions, face, None, own.full),
-    )
+    let at = if shape.cubic { step(pos, face) } else { pos };
+    coords(pad, own, at)
 }
 /// Where `tesselateFlat` reads the light of a quad of a block at `pos`: the
 /// neighbour on its cull face, else `prepareQuadFlat`'s choice (the neighbour
@@ -314,6 +281,51 @@ pub(super) fn flat_position(
         None => pos,
     }
 }
+/// A face's AO sample offsets from the sample base, in `pi` index space, so a
+/// sample is `base + offset` rather than a `pi` per coordinate triple.
+struct Samples {
+    /// The four corners (`adjacency`'s).
+    corners: [isize; 4],
+    /// Each corner stepped out of the face (the permeability sample).
+    out: [isize; 4],
+    /// Corner `a` stepped toward corner `b`.
+    diagonal: [[isize; 4]; 4],
+    /// `step(pos, face)` from the block's own cell.
+    step: isize,
+}
+const fn samples(face: D) -> Samples {
+    let mut corners = [0isize; 4];
+    let mut out = [0isize; 4];
+    let mut diagonal = [[0isize; 4]; 4];
+    let step = super::step_index(NORMALS[face as usize]);
+    let mut i = 0;
+    while i < 4 {
+        let c = super::step_index(NORMALS[ADJACENCY[face as usize].corners[i] as usize]);
+        corners[i] = c;
+        out[i] = c + step;
+        let mut j = 0;
+        while j < 4 {
+            diagonal[i][j] =
+                c + super::step_index(NORMALS[ADJACENCY[face as usize].corners[j] as usize]);
+            j += 1;
+        }
+        i += 1;
+    }
+    Samples {
+        corners,
+        out,
+        diagonal,
+        step,
+    }
+}
+const SAMPLES: [Samples; 6] = [
+    samples(D::Down),
+    samples(D::Up),
+    samples(D::North),
+    samples(D::South),
+    samples(D::West),
+    samples(D::East),
+];
 /// `prepareQuadAmbientOcclusion`: per-vertex AO brightness (before `ARGB.gray`)
 /// and smooth light coords, by vertex index.
 pub(super) fn ambient_occlusion(
@@ -321,26 +333,34 @@ pub(super) fn ambient_occlusion(
     info: &[Info],
     own: &Info,
     pos: [i32; 3],
-    positions: &[[f32; 3]; 4],
+    shape: &QuadShape,
     face: D,
 ) -> ([f32; 4], [u32; 4]) {
-    let shape = shape(positions, face, own.full);
-    let base = if shape.cubic { step(pos, face) } else { pos };
+    let samples = &SAMPLES[face as usize];
+    // The block's own cell and the sample base (the neighbour when the quad is
+    // cubic): every corner and diagonal is a constant step from it.
+    let cell = pi(pos[0], pos[1], pos[2]) as isize;
+    let base = if shape.cubic {
+        cell + samples.step
+    } else {
+        cell
+    };
     let adjacency = &ADJACENCY[face as usize];
-    let corner = |i: usize| step(base, adjacency.corners[i]);
-    let sample = |p: [i32; 3]| {
-        let s = state(pad, info, p);
-        (coords(pad, s, p), s.shade)
+    let corner = |i: usize| base + samples.corners[i];
+    let sample = |i: isize| {
+        let i = i as usize;
+        let s = state_at(pad, info, i);
+        (coords_at(pad, s, i), s.shade)
     };
     let (light0, shade0) = sample(corner(0));
     let (light1, shade1) = sample(corner(1));
     let (light2, shade2) = sample(corner(2));
     let (light3, shade3) = sample(corner(3));
-    let permeable = |i: usize| state(pad, info, step(corner(i), face)).permeable;
+    let permeable = |i: usize| state_at(pad, info, (base + samples.out[i]) as usize).permeable;
     let (p0, p1, p2, p3) = (permeable(0), permeable(1), permeable(2), permeable(3));
     let diagonal = |a: usize, b: usize, open: bool| {
         if open {
-            sample(step(corner(a), adjacency.corners[b]))
+            sample(base + samples.diagonal[a][b])
         } else {
             (light0, shade0)
         }
@@ -349,15 +369,15 @@ pub(super) fn ambient_occlusion(
     let (light03, shade03) = diagonal(0, 3, p3 || p0);
     let (light12, shade12) = diagonal(1, 2, p2 || p1);
     let (light13, shade13) = diagonal(1, 3, p3 || p1);
-    let next = step(pos, face);
-    let next_state = state(pad, info, next);
+    let next = (cell + samples.step) as usize;
+    let next_state = state_at(pad, info, next);
     let light_center = if shape.cubic || !next_state.solid {
-        coords(pad, next_state, next)
+        coords_at(pad, next_state, next)
     } else {
-        coords(pad, own, pos)
+        coords_at(pad, own, cell as usize)
     };
     let shade_center = if shape.cubic {
-        state(pad, info, base).shade
+        state_at(pad, info, base as usize).shade
     } else {
         own.shade
     };
@@ -393,6 +413,57 @@ pub(super) fn ambient_occlusion(
 #[cfg(test)]
 mod tests {
     use super::*;
+
+    #[test]
+    fn ao_offsets_match_coordinate_samples_at_section_edges() {
+        // Explicit coordinate directions, without NORMALS, ADJACENCY or step_index.
+        let (down, up, north, south, west, east) = (
+            [0, -1, 0],
+            [0, 1, 0],
+            [0, 0, -1],
+            [0, 0, 1],
+            [-1, 0, 0],
+            [1, 0, 0],
+        );
+        let faces = [
+            (D::Down, down, [west, east, north, south]),
+            (D::Up, up, [east, west, north, south]),
+            (D::North, north, [up, down, east, west]),
+            (D::South, south, [west, east, down, up]),
+            (D::West, west, [up, down, north, south]),
+            (D::East, east, [down, up, north, south]),
+        ];
+        let add = |a: [i32; 3], b: [i32; 3]| std::array::from_fn(|i| a[i] + b[i]);
+        let index = |p: [i32; 3]| pi(p[0], p[1], p[2]);
+        for x in [0, 1, 14, 15] {
+            for y in [0, 1, 14, 15] {
+                for z in [0, 1, 14, 15] {
+                    let pos = [x, y, z];
+                    for (face, normal, corners) in faces {
+                        let samples = &SAMPLES[face as usize];
+                        let cell = index(pos) as isize;
+                        assert_eq!((cell + samples.step) as usize, index(add(pos, normal)));
+                        for cubic in [false, true] {
+                            let base_pos = if cubic { add(pos, normal) } else { pos };
+                            let base = if cubic { cell + samples.step } else { cell };
+                            for (i, corner) in corners.into_iter().enumerate() {
+                                let p = add(base_pos, corner);
+                                assert_eq!((base + samples.corners[i]) as usize, index(p));
+                                assert_eq!((base + samples.out[i]) as usize, index(add(p, normal)));
+                            }
+                            for (a, b) in [(0, 2), (0, 3), (1, 2), (1, 3)] {
+                                assert_eq!(
+                                    (base + samples.diagonal[a][b]) as usize,
+                                    index(add(add(base_pos, corners[a]), corners[b]))
+                                );
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+
     const fn packed(block: u32, sky: u32) -> u32 {
         block << 4 | sky << 20
     }

crates/horizon-client-render/src/mesher/reuse_tests.rs

@@ -1,6 +1,44 @@
 use super::*;
 use crate::chunk::Light;
 
+#[test]
+fn padded_steps_match_coordinate_lookup_through_the_border() {
+    // Coordinate lookup is the old addressing path, independent of step_index
+    // and the direction table. Include every cell and the full two-cell halo.
+    let neighbors = [
+        (Direction::Down, [0, -1, 0]),
+        (Direction::Up, [0, 1, 0]),
+        (Direction::North, [0, 0, -1]),
+        (Direction::South, [0, 0, 1]),
+        (Direction::West, [-1, 0, 0]),
+        (Direction::East, [1, 0, 0]),
+    ];
+    for y in 0..16 {
+        for z in 0..16 {
+            for x in 0..16 {
+                let cell = (pi(0, y, z) + x as usize) as isize;
+                assert_eq!(cell as usize, pi(x, y, z));
+                for (face, [dx, dy, dz]) in neighbors {
+                    assert_eq!(
+                        (cell + OFFSETS[face as usize]) as usize,
+                        pi(x + dx, y + dy, z + dz)
+                    );
+                }
+                for dy in -2..=2 {
+                    for dz in -2..=2 {
+                        for dx in -2..=2 {
+                            assert_eq!(
+                                (cell + step_index([dx, dy, dz])) as usize,
+                                pi(x + dx, y + dy, z + dz)
+                            );
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
 #[test]
 fn padded_reuse_resets_missing_neighbors_and_matches_chunk_reads_across_layouts() {
     let mut pad = Padded::default();

crates/horizon-client-render/src/models/catalog.rs

@@ -9,6 +9,7 @@ use horizon_assets::{
         bind::{Properties, PropertySchema, PropertyValues, SelectedModels},
         choice::CompiledChoices,
     },
+    model::Direction,
 };
 use horizon_core::{
     position::BlockPos,
@@ -26,6 +27,65 @@ use std::{
     sync::OnceLock,
 };
 
+/// `prepareQuadShape`: the quad's bounds, whether it is partial (smaller than
+/// the block face) and whether it is cubic (flush with the block boundary, or
+/// flat on a full collision shape). A function of the quad's positions and the
+/// block's `isCollisionShapeFullBlock` only, so it is baked per face, once for
+/// each.
+#[derive(Clone, Copy)]
+pub struct QuadShape {
+    /// The quad's bounds by face index (`mesher::lighting`'s `SizeInfo`
+    /// order: down, up, north, south, west, east), and `1.0 - the bound`.
+    pub bounds: [f32; 12],
+    pub partial: bool,
+    pub cubic: bool,
+}
+impl QuadShape {
+    pub fn new(positions: &[[f32; 3]; 4], face: Direction, full: bool) -> Self {
+        // `SizeInfo` indices into the face shape.
+        const DOWN: usize = 0;
+        const UP: usize = 1;
+        const NORTH: usize = 2;
+        const SOUTH: usize = 3;
+        const WEST: usize = 4;
+        const EAST: usize = 5;
+        let (mut min, mut max) = ([32f32; 3], [-32f32; 3]);
+        for p in positions {
+            for i in 0..3 {
+                min[i] = min[i].min(p[i]);
+                max[i] = max[i].max(p[i]);
+            }
+        }
+        let mut bounds = [0f32; 12];
+        for (index, value) in [
+            (WEST, min[0]),
+            (EAST, max[0]),
+            (DOWN, min[1]),
+            (UP, max[1]),
+            (NORTH, min[2]),
+            (SOUTH, max[2]),
+        ] {
+            bounds[index] = value;
+            bounds[index + 6] = 1.0 - value;
+        }
+        let (lo, hi) = (1.0e-4f32, 0.9999f32);
+        let partial =
+            |a: usize, b: usize| min[a] >= lo || min[b] >= lo || max[a] <= hi || max[b] <= hi;
+        let (partial, cubic) = match face {
+            Direction::Down => (partial(0, 2), min[1] == max[1] && (min[1] < lo || full)),
+            Direction::Up => (partial(0, 2), min[1] == max[1] && (max[1] > hi || full)),
+            Direction::North => (partial(0, 1), min[2] == max[2] && (min[2] < lo || full)),
+            Direction::South => (partial(0, 1), min[2] == max[2] && (max[2] > hi || full)),
+            Direction::West => (partial(1, 2), min[0] == max[0] && (min[0] < lo || full)),
+            Direction::East => (partial(1, 2), min[0] == max[0] && (max[0] > hi || full)),
+        };
+        QuadShape {
+            bounds,
+            partial,
+            cubic,
+        }
+    }
+}
 pub struct BakedFace {
     pub quad: ModelQuad,
     pub layer: u32,
@@ -37,6 +97,33 @@ pub struct BakedFace {
     /// The Fusion connecting texture rule its sprite joins by ([`crate::fusion`]), plus one:
     /// two bytes, within the padding every face already has.
     pub fusion: Option<std::num::NonZeroU16>,
+    /// `prepareQuadShape` of the quad, indexed by the block's `full` flag: the
+    /// mesher would otherwise recompute it for every face of every block.
+    pub shapes: [QuadShape; 2],
+    /// The quad's own UVs in `TerrainVertex` fixed point, which the mesh
+    /// otherwise recomputes for every face of every block.
+    pub uv_fixed: [[u16; 2]; 4],
+}
+impl BakedFace {
+    pub fn new(
+        quad: ModelQuad,
+        layer: u32,
+        opaque: bool,
+        translucent: bool,
+        fusion: Option<std::num::NonZeroU16>,
+    ) -> Self {
+        let shapes = [false, true].map(|full| QuadShape::new(&quad.positions, quad.facing, full));
+        let uv_fixed = crate::mesher::baked_uv(quad.uv);
+        Self {
+            quad,
+            layer,
+            opaque,
+            translucent,
+            fusion,
+            shapes,
+            uv_fixed,
+        }
+    }
 }
 pub struct BakedModel {
     pub ambient_occlusion: bool,
@@ -97,18 +184,12 @@ fn bake_resolved(
                 Some(RenderType::Translucent | RenderType::Tripwire) => (true, false),
                 Some(RenderType::Solid) => (false, true),
                 Some(RenderType::Cutout | RenderType::CutoutMipped) => (false, false),
-                None => (
+                None | Some(RenderType::Unsupported) => (
                     quad.material.force_translucent || sprites.translucent[layer as usize],
                     sprites.region_opaque(layer, &quad.uv),
                 ),
             };
-            Ok(BakedFace {
-                translucent,
-                opaque,
-                quad,
-                layer,
-                fusion: None,
-            })
+            Ok(BakedFace::new(quad, layer, opaque, translucent, None))
         })
         .collect::<Result<_>>()?;
     let cube = super::cube::cube_styles(&faces);

crates/horizon-client-render/src/models/cube.rs

@@ -118,13 +118,7 @@ mod tests {
                         )
                         .unwrap()
                         .into_iter()
-                        .map(|quad| BakedFace {
-                            quad,
-                            layer: 7,
-                            opaque: true,
-                            translucent: false,
-                            fusion: None,
-                        })
+                        .map(|quad| BakedFace::new(quad, 7, true, false, None))
                         .collect();
                         let Some(styles) = cube_styles(&faces) else {
                             assert!(lock);
@@ -153,13 +147,7 @@ mod tests {
             bake_model_transformed(&model, BlockModelTransform::new([0; 3], false))
                 .unwrap()
                 .into_iter()
-                .map(|quad| BakedFace {
-                    quad,
-                    layer: 0,
-                    opaque: true,
-                    translucent: false,
-                    fusion: None,
-                })
+                .map(|quad| BakedFace::new(quad, 0, true, false, None))
                 .collect();
         faces[0].opaque = false;
         assert!(cube_styles(&faces).is_none());

crates/horizon-client-render/src/options_ui.rs

@@ -12,6 +12,7 @@ use crate::{
     keybinds::{self, CATEGORIES, KeyBinds, all_mappings},
     lang::{self, LanguageInfo},
     settings::{SOUND_SOURCES, Settings},
+    settings_shell as shell,
     text::{self, Style, Text},
     ui,
 };
@@ -19,6 +20,14 @@ use crate::{
 fn tr(key: &str) -> Text {
     Text::translate(key, &[])
 }
+
+/// False only in a game built without the `horizon-extras` feature (docs/forking.md), which says
+/// so once at startup: the Options screen then has vanilla's Telemetry Data slot instead of
+/// Horizon Settings and Mods, and Credits & Attribution names the official build.
+pub static HORIZON_EXTRAS: std::sync::atomic::AtomicBool = std::sync::atomic::AtomicBool::new(true);
+fn horizon_extras() -> bool {
+    HORIZON_EXTRAS.load(std::sync::atomic::Ordering::Relaxed)
+}
 fn generic(caption: &str, value: Text) -> Text {
     Text::translate("options.generic_value", &[tr(caption), value])
 }
@@ -293,6 +302,7 @@ impl Opt {
             // the namespace the client bundles (assets/horizon/lang).
             Opt::PadEnabled => "horizon.options.controller",
             Opt::PadVibration => "horizon.options.vibration",
+            Opt::PadPlayInBackground => "horizon.options.play_in_background",
             Opt::PadAdaptiveTriggers => "horizon.options.adaptive_triggers",
             Opt::PadLightbar => "horizon.options.lightbar",
             Opt::PadLookSensitivity => "horizon.options.look_sensitivity",
@@ -308,6 +318,7 @@ impl Opt {
             Opt::PadTriggerThreshold => "horizon.options.trigger_threshold",
             Opt::PadGlyphs => "horizon.options.button_glyphs",
             Opt::PadKeyboard => "horizon.options.on_screen_keyboard",
+            Opt::PadGameplayGuide => "horizon.options.gameplay_guide",
             Opt::ModelPart(i) => [
                 "options.modelPart.cape",
                 "options.modelPart.jacket",
@@ -828,7 +839,13 @@ impl Opt {
             Opt::JapaneseGlyphs => on_off(s.japanese_glyphs),
             Opt::PadEnabled => on_off(s.controller.enabled),
             Opt::PadVibration => on_off(s.controller.vibration),
+            Opt::PadPlayInBackground => on_off(s.controller.play_in_background),
             Opt::PadAdaptiveTriggers => on_off(s.controller.adaptive_triggers),
+            Opt::PadGameplayGuide => tr(match s.controller.guide_detail {
+                gamepad::GuideDetail::Full => "horizon.options.gameplay_guide.full",
+                gamepad::GuideDetail::Basic => "horizon.options.gameplay_guide.basic",
+                gamepad::GuideDetail::Off => "horizon.options.gameplay_guide.off",
+            }),
             Opt::PadInvertX => on_off(s.controller.invert_x),
             Opt::PadInvertY => on_off(s.controller.invert_y),
             Opt::PadToggleSneak => tr(if s.controller.toggle_sneak {
@@ -1125,6 +1142,9 @@ impl Opt {
             Opt::JapaneseGlyphs => s.japanese_glyphs = !s.japanese_glyphs,
             Opt::PadEnabled => s.controller.enabled = !s.controller.enabled,
             Opt::PadVibration => s.controller.vibration = !s.controller.vibration,
+            Opt::PadPlayInBackground => {
+                s.controller.play_in_background = !s.controller.play_in_background
+            }
             Opt::PadAdaptiveTriggers => {
                 s.controller.adaptive_triggers = !s.controller.adaptive_triggers
             }
@@ -1146,6 +1166,14 @@ impl Opt {
                     .unwrap_or(0) as u8;
                 s.controller.glyphs = GlyphStyle::ALL[usize::from(next(i, 4))];
             }
+            Opt::PadGameplayGuide => {
+                let all = gamepad::GuideDetail::ALL;
+                let i = all
+                    .iter()
+                    .position(|d| *d == s.controller.guide_detail)
+                    .unwrap_or(0) as u8;
+                s.controller.guide_detail = all[usize::from(next(i, 3))];
+            }
             Opt::PadKeyboard => {
                 let all = gamepad::TextKeyboard::ALL;
                 let i = all
@@ -1515,6 +1543,8 @@ pub enum Event {
     PlayMusicTrack(String, String),
     /// Open the recordings folder in the system file browser.
     OpenStudioFolder,
+    /// Start playback from the selected Studio recording.
+    OpenStudioReplay(std::path::PathBuf),
 }
 /// A row of the Music page: the track, and the pool it is played from.
 #[derive(Clone, Debug, Default, PartialEq)]
@@ -1617,6 +1647,8 @@ pub struct OptionsUi {
     center_language: bool,
     pub graphics: crate::graphics_ui::GraphicsUi,
     pub controller: crate::controller_ui::ControllerUi,
+    /// Horizon Extras, on the settings shell.
+    extras: shell::Shell<crate::extras_ui::ExtrasScreen>,
     pub shader: crate::shader_ui::ShaderUi,
     pub split_profiles: crate::split_profiles::SplitProfiles,
     /// HDR calibration while its page is open.
@@ -1649,7 +1681,7 @@ pub struct OptionsUi {
     /// The list's rows as last laid out: each row's top and bottom (GUI
     /// pixels), for the narration's row under the mouse.
     row_bands: Vec<[f32; 2]>,
-    /// The Extras or PvP & HUD items that take a whole row (`wide_extras`), measured
+    /// The PvP & HUD items that take a whole row (`wide_extras`), measured
     /// when the page is drawn.
     wide_extras: Vec<crate::extras::Item>,
 }
@@ -1695,6 +1727,7 @@ impl Default for OptionsUi {
             center_language: false,
             graphics: Default::default(),
             controller: Default::default(),
+            extras: Default::default(),
             shader: Default::default(),
             split_profiles: Default::default(),
             calibration: None,
@@ -1763,24 +1796,23 @@ fn option_widget(s: &Settings, opt: Opt, x: f32, y: f32, w: f32) -> Widget {
         Kind::Cycle => button(x, y, w, opt.label(s), Act::Cycle(opt)),
     }
 }
-/// The Extras or PvP & HUD page's rows: its items under their headers.
-fn extras_rows(page: Page) -> Vec<Result<crate::extras::Item, &'static str>> {
-    match page {
-        Page::Pvp => crate::pvp::rows()
-            .into_iter()
-            .map(|r| r.map(crate::extras::Item::Pvp))
-            .collect(),
-        _ => crate::extras::rows(),
-    }
+/// The least GUI size a shell screen lays its keys out for, before it has been drawn at its own.
+const MIN_KEY_GUI: (f32, f32) = (480.0, 240.0);
+/// The PvP & HUD page's rows: its items under their headers.
+fn pvp_rows() -> Vec<Result<crate::extras::Item, &'static str>> {
+    crate::pvp::rows()
+        .into_iter()
+        .map(|r| r.map(crate::extras::Item::Pvp))
+        .collect()
 }
-/// The items of `page`'s rows whose label, with any of their first values, is wider than a
+/// The items of PvP & HUD's rows whose label, with any of their first values, is wider than a
 /// half-width button holds (`width` measures text with the screen's font): those take the
 /// whole row, so no label slides past its edges, in any language.
-fn wide_extras(s: &Settings, page: Page, width: impl Fn(&str) -> f32) -> Vec<crate::extras::Item> {
+fn wide_extras(s: &Settings, width: impl Fn(&str) -> f32) -> Vec<crate::extras::Item> {
     // A button's label keeps 2 px off each edge (`AbstractButton.renderString`'s margin),
     // past which it slides back and forth.
     let room = 150.0 - 4.0;
-    extras_rows(page)
+    pvp_rows()
         .into_iter()
         .filter_map(Result::ok)
         .filter(|&item| {
@@ -2004,6 +2036,9 @@ impl OptionsUi {
         if !self.focus_from_keyboard {
             self.focus = None;
         }
+        if let Some(shell) = self.shell_mut() {
+            shell.blur_search();
+        }
     }
     /// A switch of `horizon-extras.txt` as the Extras page draws it: "Caption: On".
     fn extra_button(&self, s: &Settings, item: crate::extras::Item) -> Widget {
@@ -2056,7 +2091,10 @@ impl OptionsUi {
                 }
                 Page::Controller | Page::PadBinds => self.controller.typing(),
                 _ if Self::shader_page(self.page()).is_some() => self.shader.typing(),
-                _ => self.settings_search_active(),
+                _ => match self.shell() {
+                    Some(shell) => shell.typing(),
+                    None => self.settings_search_active(),
+                },
             }
     }
     /// Jump straight to a page (control socket / tests).
@@ -2172,6 +2210,9 @@ impl OptionsUi {
         if let Some(at) = Self::shader_page(page) {
             self.shader.open(at);
         }
+        if let Some(shell) = self.shell_mut() {
+            shell.open();
+        }
         if page == Page::SplitSetup {
             self.split_setup.reset();
         }
@@ -2182,6 +2223,34 @@ impl OptionsUi {
             self.studio.refresh();
         }
     }
+    /// The open page's screen on the settings shell. This, with `shell_mut`, is all a screen
+    /// needs here: drawing, clicks, the wheel, a stick's scrolling, keys and typing all go
+    /// through them, so no input path can miss one.
+    fn shell(&self) -> Option<&dyn shell::Hosted> {
+        match self.page() {
+            Page::Extras => Some(&self.extras),
+            _ => None,
+        }
+    }
+    fn shell_mut(&mut self) -> Option<&mut dyn shell::Hosted> {
+        match self.page() {
+            Page::Extras => Some(&mut self.extras),
+            _ => None,
+        }
+    }
+    /// What a shell screen's outputs do to these options.
+    fn shell_events(&mut self, s: &mut Settings, outputs: Vec<shell::Output>) -> Vec<Event> {
+        let mut events = Vec::new();
+        for output in outputs {
+            match output {
+                shell::Output::Event(event) => events.push(event),
+                shell::Output::BindKey(name) => self.selected_key = Some(name),
+                shell::Output::Push(page) => self.push(page),
+                shell::Output::Done => events.extend(self.back(s)),
+            }
+        }
+        events
+    }
     /// What the graphics screen's actions do to these options.
     fn graphics_events(
         &mut self,
@@ -2532,41 +2601,6 @@ impl OptionsUi {
         }
         rows
     }
-    /// The row that reaches the Zoom mod that replaced the extra: its switch and settings page
-    /// when it is built in, else a note saying where it is installed (Options > Mods). Zoom
-    /// became an official native mod, so Extras has no setting of its own for it (#8713).
-    fn zoom_mod_row(s: &Settings) -> Row {
-        let Some(i) = s
-            .mods
-            .installed
-            .iter()
-            .position(|m| m.id == "zoom" && m.native.is_some())
-        else {
-            // A note, not a button: Options > Mods already has the one way into the Mods page
-            // (`every_setting_and_page_is_reached_from_one_place`).
-            return Row::Note(lang::get("horizon.extras.zoom_mod_install"));
-        };
-        let label = || Text::option_name_value(tr("horizon.extras.zoom"), on_off(s.mods.is_on(i)));
-        let toggle = |width| button(0.0, 0.0, width, label(), Act::ToggleMod(i));
-        let settings = s.mods.installed[i]
-            .native
-            .as_ref()
-            .is_some_and(|page| !page.keys.is_empty() || !page.buttons.is_empty());
-        if settings {
-            Row::Buttons(
-                toggle(150.0),
-                Some(button(
-                    0.0,
-                    0.0,
-                    150.0,
-                    tr("horizon.mods.settings"),
-                    Act::ModSettings(i),
-                )),
-            )
-        } else {
-            Row::Buttons(toggle(310.0), None)
-        }
-    }
     /// A native mod's page: its name, its keys as Key Binds rows (the
     /// player's choice, else the default), then its buttons.
     fn native_rows(&self, s: &Settings, i: usize) -> Vec<Row> {
@@ -2607,7 +2641,7 @@ impl OptionsUi {
     fn list_rows(&self, s: &Settings) -> Vec<Row> {
         match self.page() {
             Page::SplitSetup => Vec::new(),
-            Page::Extras | Page::Pvp => {
+            Page::Pvp => {
                 // Each section's switches two to a row, as vanilla's
                 // OptionsList.addSmall lays out an options screen; one whose label would run
                 // past half a row in this language (`wide_extras`) gets the whole row.
@@ -2635,21 +2669,12 @@ impl OptionsUi {
                         widget
                     }
                 };
-                // PvP & HUD opens with its preset; Extras doesn't repeat it, nor the way there
-                // (Horizon Settings has it).
+                // PvP & HUD opens with its preset (Horizon Settings has the way there).
                 let preset = button(0.0, 0.0, 150.0, tr("horizon.pvp.preset"), Act::PvpPreset);
-                let mut rows = Vec::new();
-                if self.page() == Page::Extras {
-                    // Zoom, the FPS counter, Keystrokes and the Minimap are official mods now;
-                    // Extras keeps a way to the one players look for here (#8713).
-                    rows.push(Self::zoom_mod_row(s));
-                }
-                if self.page() == Page::Pvp {
-                    // The editor moves what the game shows: only from a world.
-                    let edit = button(0.0, 0.0, 150.0, tr("horizon.pvp.editor"), Act::HudEditor);
-                    let edit = if self.in_world { edit } else { inactive(edit) };
-                    rows.push(Row::Buttons(preset, Some(edit)));
-                }
+                // The editor moves what the game shows: only from a world.
+                let edit = button(0.0, 0.0, 150.0, tr("horizon.pvp.editor"), Act::HudEditor);
+                let edit = if self.in_world { edit } else { inactive(edit) };
+                let mut rows = vec![Row::Buttons(preset, Some(edit))];
                 let mut section = Vec::new();
                 let flush = |rows: &mut Vec<Row>, section: &mut Vec<crate::extras::Item>| {
                     let mut half = None;
@@ -2665,7 +2690,7 @@ impl OptionsUi {
                     }
                     rows.extend(half.map(|h| Row::Buttons(extra(h, 150.0), None)));
                 };
-                for row in extras_rows(self.page()) {
+                for row in pvp_rows() {
                     match row {
                         Err(header) => {
                             flush(&mut rows, &mut section);
@@ -3096,6 +3121,22 @@ impl OptionsUi {
                     ("horizon.pages.open.mods", Some(Page::Mods)),
                     ("options.credits_and_attribution", Some(Page::Credits)),
                 ];
+                // horizon-extras: without it, vanilla's last row instead of Horizon Settings and
+                // Mods: Telemetry Data (greyed: nothing is sent) and Credits & Attribution.
+                let plain;
+                let entries: &[_] = if horizon_extras() {
+                    &entries
+                } else {
+                    plain = [
+                        &entries[..entries.len() - 3],
+                        &[
+                            ("options.telemetry", None),
+                            ("options.credits_and_attribution", Some(Page::Credits)),
+                        ],
+                    ]
+                    .concat();
+                    &plain
+                };
                 let rows = entries.len().div_ceil(2) as f32;
                 let gy = (61.0 + 30.0f32).min(h - 33.0 - rows * 24.0);
                 for (i, (key, page)) in entries.iter().enumerate() {
@@ -3145,6 +3186,22 @@ impl OptionsUi {
                     let y = y + 28.0 * (i + 1) as f32;
                     out.push(inactive(button(x, y, 210.0, tr(key), Act::None)));
                 }
+                // horizon-extras: a build without them says where the official one is.
+                if !horizon_extras() {
+                    out.push(Widget {
+                        x: 0.0,
+                        y: (y + 92.0).min(h - 42.0),
+                        w,
+                        h: 9.0,
+                        kind: WKind::Text {
+                            text: tr("horizon.plain.official"),
+                            color: 0xFFA0A0A0,
+                            centered: true,
+                        },
+                        list: false,
+                        row: 0,
+                    });
+                }
                 out.push(done(h - 27.0));
                 top = 0.0;
                 bottom = 0.0;
@@ -3647,6 +3704,12 @@ impl OptionsUi {
             self.shader.draw(s, batch, atlas, cursor, self.in_world);
             return;
         }
+        let waiting = self.selected_key;
+        let in_world = self.in_world;
+        if let Some(shell) = self.shell_mut() {
+            shell.draw(s, batch, atlas, cursor, in_world, waiting);
+            return;
+        }
         if self.page() == Page::SplitSetup {
             self.split_setup.on = s.extras.splitscreen;
             // The controller picks a tile up between presses: the screen's size from the draw.
@@ -3675,8 +3738,8 @@ impl OptionsUi {
             crate::screen_draw::paint(batch, atlas, &draws);
             return;
         }
-        if matches!(self.page(), Page::Extras | Page::Pvp) {
-            self.wide_extras = wide_extras(s, self.page(), |t| atlas.font.width(t));
+        if self.page() == Page::Pvp {
+            self.wide_extras = wide_extras(s, |t| atlas.font.width(t));
         }
         let (widgets, top, bottom, content) = self.layout(s, w, h);
         self.size = (w, h);
@@ -3978,6 +4041,9 @@ impl OptionsUi {
             return match self.studio.click((x, y), size) {
                 StudioAction::None => Vec::new(),
                 StudioAction::Refresh => vec![Event::ButtonClick],
+                StudioAction::OpenReplay(path) => {
+                    vec![Event::ButtonClick, Event::OpenStudioReplay(path)]
+                }
                 StudioAction::OpenFolder => vec![Event::ButtonClick, Event::OpenStudioFolder],
                 StudioAction::Back => {
                     let mut events = vec![Event::ButtonClick];
@@ -4010,6 +4076,22 @@ impl OptionsUi {
                     .click(s, (x, y), size, framebuffer, drag, right, self.shift);
             return self.graphics_events(s, actions);
         }
+        if self.shell().is_some() {
+            // Waiting on a key: a mouse button binds, as on Key Binds.
+            if self.selected_key.is_some() && !drag {
+                let button = if right {
+                    winit::event::MouseButton::Right
+                } else {
+                    winit::event::MouseButton::Left
+                };
+                return self.bind_mouse(s, button);
+            }
+            let shift = self.shift;
+            let outputs = self.shell_mut().map_or_else(Vec::new, |shell| {
+                shell.click(s, (x, y), size, drag, right, shift)
+            });
+            return self.shell_events(s, outputs);
+        }
         if Self::controller_page(self.page()).is_some() {
             // Waiting on a button: a click cancels the wait.
             if !drag && self.selected_pad_action.take().is_some() {
@@ -4286,7 +4368,9 @@ impl OptionsUi {
         // release, even if the pointer has left the widget or its value stayed.
         let slider = self.dragging.take().is_some();
         let (shader_slider, shader_pack) = self.shader.release();
-        let graphics_slider = self.graphics.release() | self.controller.release() | shader_slider;
+        let shell_slider = self.shell_mut().is_some_and(|shell| shell.release());
+        let graphics_slider =
+            self.graphics.release() | self.controller.release() | shader_slider | shell_slider;
         let calibration_slider = self.calibration.as_mut().is_some_and(|c| c.release());
         let split_drop = self.split_setup.release();
         if slider || graphics_slider || calibration_slider {
@@ -4364,6 +4448,13 @@ impl OptionsUi {
     ) -> Vec<Event> {
         self.size = size;
         self.framebuffer = framebuffer;
+        if self.resource_error.is_some() {
+            return Vec::new();
+        }
+        if let Some(shell) = self.shell_mut() {
+            let outputs = shell.wheel(s, size, cursor, amount);
+            return self.shell_events(s, outputs);
+        }
         if Self::graphics_page(self.page()).is_some() {
             let actions = self.graphics.wheel(s, size, cursor, framebuffer, amount);
             return self.graphics_events(s, actions);
@@ -4455,10 +4546,18 @@ impl OptionsUi {
         if self.resource_error.is_some() {
             return;
         }
+        if let Some(shell) = self.shell_mut() {
+            shell.scroll(s, size, amount);
+            return;
+        }
         if Self::graphics_page(self.page()).is_some() {
             self.graphics.scroll(s, size, amount);
             return;
         }
+        if self.page() == Page::Studio {
+            self.studio.wheel(amount);
+            return;
+        }
         if Self::controller_page(self.page()).is_some() {
             self.controller.scroll(s, size, amount);
             return;
@@ -4647,6 +4746,10 @@ impl OptionsUi {
             self.scroll = 0.0;
         } else if self.page() == Page::SplitProfiles {
             self.split_profiles.type_text(text);
+        } else if let Some(shell) = self.shell_mut() {
+            if shell.typing() {
+                shell.type_text(text);
+            }
         } else if Self::graphics_page(self.page()).is_some() && self.graphics.typing() {
             self.graphics.type_text(text);
         } else if Self::controller_page(self.page()).is_some() && self.controller.typing() {
@@ -4684,6 +4787,9 @@ impl OptionsUi {
         if self.page() == Page::SplitProfiles {
             return self.split_profiles.shortcut(shortcut, clipboard);
         }
+        if let Some(shell) = self.shell_mut() {
+            return shell.shortcut(shortcut, clipboard);
+        }
         if Self::graphics_page(self.page()).is_some() {
             return self.graphics.shortcut(shortcut, clipboard);
         }
@@ -4817,6 +4923,14 @@ impl OptionsUi {
             }
             return events;
         }
+        let gui = (
+            self.size.0.max(MIN_KEY_GUI.0),
+            self.size.1.max(MIN_KEY_GUI.1),
+        );
+        if let Some(shell) = self.shell_mut() {
+            let outputs = shell.key(s, key, text, shift, gui);
+            return self.shell_events(s, outputs);
+        }
         if Self::controller_page(self.page()).is_some() {
             let size = (self.size.0.max(480.0), self.size.1.max(240.0));
             let fb = [self.framebuffer[0].max(480), self.framebuffer[1].max(240)];
@@ -5175,6 +5289,7 @@ impl OptionsUi {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::extras_ui::ExtraRow;
 
     /// The window allows the input method only while `typing` says a search
     /// box has the focus (`Game::text_field_focused`), so a page without one
@@ -5620,6 +5735,9 @@ mod tests {
                 if ui.controller_open() {
                     texts.extend(ui.controller.row_names(&s));
                 }
+                if ui.page() == Page::Extras {
+                    texts.extend(ui.extras.row_labels(&s));
+                }
             }
             texts
         })
@@ -5988,7 +6106,7 @@ mod tests {
         let atlas = atlas();
         let mut s = Settings::default();
         let mut ui = OptionsUi::default();
-        ui.show(Page::Extras);
+        ui.show(Page::Pvp);
         let (widgets, _, _, _) = ui.layout(&s, 480.0, 480.0);
         let extra = widgets
             .iter()
@@ -5998,7 +6116,7 @@ mod tests {
                     WKind::Button {
                         act: Act::Extra(item),
                         ..
-                    } if !matches!(item, crate::extras::Item::SortKey)
+                    } if item.key_name().is_none()
                 )
             })
             .unwrap();
@@ -6044,19 +6162,17 @@ mod tests {
 
     #[test]
     fn extras_reaches_the_zoom_mod_that_replaced_the_extra() {
+        let atlas = atlas();
         let mut s = Settings::default();
         let mut ui = OptionsUi::default();
         ui.show(Page::Extras);
         let english = || lang::Language::load(&[], "en_us");
         // Without the mod, Extras says where it is installed (a note, not a second way into
         // Options > Mods).
-        let (widgets, _, _, _) = lang::scoped(english(), || ui.layout(&s, 480.0, 4000.0)).0;
+        let labels = lang::scoped(english(), || ui.extras.row_labels(&s)).0;
         assert!(
-            widgets.iter().any(|w| matches!(
-                &w.kind,
-                WKind::Text { text, .. } if text.plain() == "Zoom: install from Mods"
-            )),
-            "Extras has no hint for the Zoom mod"
+            labels.iter().any(|l| l == "Zoom: install from Mods"),
+            "Extras has no hint for the Zoom mod: {labels:?}"
         );
         // Built in, Zoom's settings live on its page: Extras opens that page.
         s.mods.installed.push(crate::mod_list::Installed {
@@ -6070,30 +6186,28 @@ mod tests {
                 buttons: Vec::new(),
             }),
         });
-        let (widgets, _, _, _) = lang::scoped(english(), || ui.layout(&s, 480.0, 4000.0)).0;
-        assert!(
-            widgets.iter().any(|w| matches!(
-                &w.kind,
-                WKind::Button {
-                    act: Act::ModSettings(0),
-                    label,
-                    ..
-                } if label.plain() == "Settings"
-            )),
-            "Extras doesn't open the Zoom mod's settings"
+        let labels = lang::scoped(english(), || ui.extras.row_labels(&s)).0;
+        assert!(labels.iter().any(|l| l == "Settings"), "{labels:?}");
+        // The mod's switch is beside it, so Extras keeps the Zoom setting it had.
+        assert!(labels.iter().any(|l| l.starts_with("Zoom: ")), "{labels:?}");
+        let size = (480.0, 480.0);
+        let on = s.mods.is_on(0);
+        let at = ui.extras.point_at(&s, size, ExtraRow::Zoom(0));
+        assert_eq!(
+            ui.click(&mut s, &atlas, at.0, at.1, size, [960, 960], false, false),
+            vec![Event::ButtonClick, Event::Changed]
         );
-        // The mod's switch is on the same row, so Extras keeps the Zoom setting it had.
-        assert!(
-            widgets.iter().any(|w| matches!(
-                &w.kind,
-                WKind::Button {
-                    act: Act::ToggleMod(0),
-                    label,
-                    ..
-                } if label.plain().starts_with("Zoom")
-            )),
-            "Extras doesn't switch the Zoom mod"
+        assert_ne!(s.mods.is_on(0), on);
+        let at = ui.extras.point_at(&s, size, ExtraRow::ZoomSettings(0));
+        assert_eq!(
+            ui.click(&mut s, &atlas, at.0, at.1, size, [960, 960], false, false),
+            vec![
+                Event::ButtonClick,
+                Event::ButtonClick,
+                Event::NativeSettings(0)
+            ]
         );
+        assert_eq!(ui.page(), Page::NativeMod(0));
     }
 
     #[test]
@@ -6437,32 +6551,27 @@ mod tests {
             );
             assert_eq!(ui.page(), page);
         }
-        let (widgets, _, _, _) = ui.layout(&s, size.0, size.1);
         assert_eq!(
-            widgets
-                .iter()
-                .filter(|w| matches!(
-                    w.kind,
-                    WKind::Button {
-                        act: Act::Extra(_),
-                        ..
-                    }
-                ))
-                .count(),
-            crate::extras::rows().iter().filter(|r| r.is_ok()).count()
+            ui.extras.row_labels(&s).len(),
+            // And the note about the Zoom mod over them.
+            1 + crate::extras::rows().iter().filter(|r| r.is_ok()).count()
         );
+        let press = |ui: &mut OptionsUi, s: &mut Settings, item: crate::extras::Item| {
+            let at = ui.extras.point_at(s, size, ExtraRow::Item(item));
+            ui.click(s, &atlas, at.0, at.1, size, [960, 960], false, false)
+        };
         assert_eq!(
-            click(&mut ui, &mut s, Act::Extra(crate::extras::Item::Sort)),
+            press(&mut ui, &mut s, crate::extras::Item::Sort),
             vec![Event::ButtonClick, Event::Changed]
         );
         assert!(s.extras.sort);
         assert_eq!(
-            click(&mut ui, &mut s, Act::Extra(crate::extras::Item::Pregen)),
+            press(&mut ui, &mut s, crate::extras::Item::Pregen),
             vec![Event::ButtonClick, Event::Changed]
         );
         assert!(s.extras.pregen);
         assert_eq!(
-            click(&mut ui, &mut s, Act::Extra(crate::extras::Item::SortKey)),
+            press(&mut ui, &mut s, crate::extras::Item::SortKey),
             vec![Event::ButtonClick]
         );
         assert_eq!(ui.selected_key, Some(crate::extras::SORT_KEY));
@@ -6475,12 +6584,6 @@ mod tests {
             crate::extras::Extras::parse(&s.extras.serialize()),
             s.extras
         );
-        // In a window too short for the page, the wheel scrolls to its end.
-        let short = (480.0, 180.0);
-        ui.scroll(&s, short, -1000.0);
-        let (_, top, bottom, content) = ui.layout(&s, short.0, short.1);
-        assert!(content > bottom - top);
-        assert_eq!(ui.scroll, content - (bottom - top));
         assert_eq!(
             ui.key(&mut s, &atlas, winit::keyboard::KeyCode::Escape, None),
             vec![Event::Changed]
@@ -6488,6 +6591,24 @@ mod tests {
         assert_eq!(ui.page(), Page::Horizon);
     }
 
+    /// Every way a pad or a wheel scrolls a page on the shell moves the same list: Replay Studio's
+    /// took the wheel and missed `scroll_at`, so a stick couldn't scroll it.
+    #[test]
+    fn the_wheel_and_the_stick_scroll_a_page_on_the_shell_alike() {
+        let mut s = Settings::default();
+        let mut ui = OptionsUi::default();
+        ui.show(Page::Extras);
+        // Too short for the page.
+        let short = (480.0, 180.0);
+        ui.wheel(&mut s, short, (0.0, 0.0), [960, 360], -1.0);
+        let one = ui.extras.scroll_amount();
+        assert!(one > 0.0);
+        ui.scroll_at(&s, short, (0.0, 0.0), -1.0);
+        assert_eq!(ui.extras.scroll_amount(), 2.0 * one);
+        ui.scroll_at(&s, short, (0.0, 0.0), 2.0);
+        assert_eq!(ui.extras.scroll_amount(), 0.0);
+    }
+
     #[test]
     fn classic_graphics_presets_set_the_distances() {
         let atlas = atlas();
@@ -7318,7 +7439,7 @@ mod tests {
     /// An Extras or PvP & HUD label wider than half a row takes the whole row, so every label
     /// fits its button: "Keep channels for UI sounds: Off" did not.
     #[test]
-    fn extras_labels_fit_their_buttons() {
+    fn pvp_labels_fit_their_buttons() {
         // Vanilla's font: 6 px a glyph, a few narrower ones.
         let width = |t: &str| {
             t.chars()
@@ -7333,9 +7454,9 @@ mod tests {
         };
         let s = Settings::default();
         let mut ui = OptionsUi::default();
-        for page in [Page::Extras, Page::Pvp] {
-            ui.stack = vec![Page::Main, page];
-            ui.wide_extras = wide_extras(&s, page, width);
+        {
+            ui.stack = vec![Page::Main, Page::Pvp];
+            ui.wide_extras = wide_extras(&s, width);
             let rows = ui.list_rows(&s);
             let buttons: Vec<&Widget> = rows
                 .iter()
@@ -7349,20 +7470,11 @@ mod tests {
                     continue;
                 };
                 let label = label.plain();
-                assert!(width(&label) <= b.w - 4.0, "{page:?}: {label} on {}", b.w);
+                assert!(width(&label) <= b.w - 4.0, "{label} on {}", b.w);
             }
             // Short ones keep vanilla's two to a row.
-            assert!(buttons.iter().any(|b| b.w == 150.0), "{page:?}");
+            assert!(buttons.iter().any(|b| b.w == 150.0));
         }
-        ui.stack = vec![Page::Main, Page::Extras];
-        ui.wide_extras = wide_extras(&s, Page::Extras, width);
-        for item in [
-            crate::extras::Item::UiSoundReserve,
-            crate::extras::Item::WheelCyclesSettings,
-        ] {
-            assert!(ui.wide_extras.contains(&item), "{item:?}");
-        }
-        assert!(!ui.wide_extras.contains(&crate::extras::Item::AutoReconnect));
     }
 
     /// Every setting a player reaches, from the Options screen through every button that opens
@@ -7778,20 +7890,9 @@ mod tests {
         s.extras.wheel_cycles_settings = true;
         ui.show(Page::Extras);
         let size = (480.0, 600.0);
-        let (widgets, _, _, _) = ui.layout(&s, size.0, size.1);
-        let sort_wd = widgets
-            .iter()
-            .find(|w| {
-                matches!(
-                    w.kind,
-                    WKind::Button {
-                        act: Act::Extra(crate::extras::Item::Sort),
-                        ..
-                    }
-                )
-            })
-            .unwrap();
-        let cursor = (sort_wd.x + 5.0, sort_wd.y + 5.0);
+        let cursor = ui
+            .extras
+            .point_at(&s, size, ExtraRow::Item(crate::extras::Item::Sort));
         assert!(!s.extras.sort);
         ui.wheel(&mut s, size, cursor, [854, 480], 1.0);
         assert!(s.extras.sort);
@@ -8274,55 +8375,5 @@ mod tests {
         ui.click(&mut s, &atlas, px, py, size, [854, 480], false, false);
         assert_eq!(s.particles, 0);
         ui.shift = false;
-
-        // Also verify Act::Extra on Page::Extras
-        ui.show(Page::Extras);
-        let (widgets, top, _, _) = ui.layout(&s, size.0, size.1);
-        if let Some(extra_btn) = widgets.iter().find(|wd| {
-            matches!(
-                wd.kind,
-                WKind::Button {
-                    active: true,
-                    act: Act::Extra(crate::extras::Item::CosmeticsOthers),
-                    ..
-                }
-            )
-        }) {
-            // Extras has enough rows to scroll: click the cycle button inside
-            // the list's viewport, as a player would after scrolling to it.
-            ui.scroll = (extra_btn.y - top).max(0.0);
-            let (widgets, _, _, _) = ui.layout(&s, size.0, size.1);
-            let extra_btn = widgets
-                .iter()
-                .find(|wd| {
-                    matches!(
-                        wd.kind,
-                        WKind::Button {
-                            act: Act::Extra(crate::extras::Item::CosmeticsOthers),
-                            ..
-                        }
-                    )
-                })
-                .unwrap();
-            let (ex, ey) = (extra_btn.x + 1.0, extra_btn.y + 1.0);
-            use horizon_cosmetics::prefs::Others;
-            // Not chosen, nothing owned: shows Hidden.
-            assert_eq!(s.extras.cosmetics_others, None);
-            assert_eq!(s.extras.effective_others(), Others::Hidden);
-
-            // Forward (wraps to Shown), now a choice
-            ui.click(&mut s, &atlas, ex, ey, size, [854, 480], false, false);
-            assert_eq!(s.extras.cosmetics_others, Some(Others::Shown));
-
-            // Backward with shift
-            ui.shift = true;
-            ui.click(&mut s, &atlas, ex, ey, size, [854, 480], false, false);
-            assert_eq!(s.extras.cosmetics_others, Some(Others::Hidden));
-
-            // Backward again
-            ui.click(&mut s, &atlas, ex, ey, size, [854, 480], false, false);
-            assert_eq!(s.extras.cosmetics_others, Some(Others::NameTags));
-            ui.shift = false;
-        }
     }
 }

crates/horizon-client-render/src/particles.rs

@@ -58,6 +58,8 @@ pub struct ParticleOptions {
     /// A native mod's own particle type, by its namespaced name (`mymod:spark`):
     /// `SimpleParticleType` plus the provider `particles/<name>.json` names.
     pub mod_particle: Option<String>,
+    /// Pre-1.20.5 entity-effect providers use spawn velocity as RGB; true is the ambient provider.
+    pub legacy_entity_effect: Option<bool>,
 }
 impl ParticleOptions {
     pub fn simple(ty: ParticleType) -> Self {
@@ -72,6 +74,7 @@ impl ParticleOptions {
             geyser: None,
             vibration: None,
             mod_particle: None,
+            legacy_entity_effect: None,
         }
     }
     /// A native mod's `SimpleParticleType`: the sprite set of
@@ -3167,8 +3170,16 @@ impl ParticleEngine {
                         q.set_color(b, 0.0, b);
                     }
                     T::EntityEffect => {
-                        q.set_color(o.color[0], o.color[1], o.color[2]);
-                        q.rgba[3] = o.color[3];
+                        if let Some(ambient) = o.legacy_entity_effect {
+                            q.set_color(v[0] as f32, v[1] as f32, v[2] as f32);
+                            // AmbientMobProvider overrides constructor alpha; MobProvider only sets RGB.
+                            if ambient {
+                                q.rgba[3] = 0.15;
+                            }
+                        } else {
+                            q.set_color(o.color[0], o.color[1], o.color[2]);
+                            q.rgba[3] = o.color[3];
+                        }
                     }
                     T::Effect | T::InstantEffect => {
                         q.set_color(o.color[0], o.color[1], o.color[2]);
@@ -3177,7 +3188,12 @@ impl ParticleEngine {
                     _ => {}
                 }
                 q.behaviour = Behaviour::Spell {
-                    original_alpha: q.rgba[3],
+                    // The old SpellParticle.tick always eased back to 1, including ambient effects.
+                    original_alpha: if o.legacy_entity_effect.is_some() {
+                        1.0
+                    } else {
+                        q.rgba[3]
+                    },
                 };
                 q.set = set;
                 q
@@ -3469,7 +3485,13 @@ impl ParticleEngine {
                     scaled(o.color[2], jb),
                 );
                 q.size = 0.26;
-                q.lifetime = duration;
+                // The older-server adapter marks pre-1.21.4 TargetColorParticleOption with -1.
+                // Its TrailParticle.Provider chose nextInt(40) + 10 after constructing the particle.
+                q.lifetime = if duration == -1 {
+                    self.level_random.next_int_bound(40).unwrap_or(0) + 10
+                } else {
+                    duration
+                };
                 q.has_physics = false;
                 q.free_move = true;
                 q.light = Light::FullBright;
@@ -4941,6 +4963,45 @@ const CREEPER: [[f64; 2]; 12] = [
 mod tests {
     use super::*;
 
+    #[test]
+    fn legacy_spell_providers_use_velocity_rgb_and_their_original_alpha_rules() {
+        let mut engine = ParticleEngine::new(Path::new(""), &HashMap::new(), &HashSet::new());
+        let velocity = [0.25, 0.5, 0.75];
+        for scoped in [false, true] {
+            engine.set_scope_eye(scoped.then_some([0.0; 3]));
+            for ambient in [false, true] {
+                let mut options =
+                    ParticleOptions::colored(ParticleType::EntityEffect, [1.0, 0.0, 0.0, 0.8]);
+                options.legacy_entity_effect = Some(ambient);
+                let particle = engine.make(&options, [0.0; 3], velocity, 7).unwrap();
+                let alpha = if ambient {
+                    0.15
+                } else if scoped {
+                    0.0
+                } else {
+                    1.0
+                };
+                assert_eq!(particle.rgba, [0.25, 0.5, 0.75, alpha]);
+                assert_eq!(
+                    particle.behaviour,
+                    Behaviour::Spell {
+                        original_alpha: 1.0
+                    }
+                );
+            }
+            let options =
+                ParticleOptions::colored(ParticleType::EntityEffect, [1.0, 0.0, 0.0, 0.8]);
+            let current = engine.make(&options, [0.0; 3], velocity, 7).unwrap();
+            assert_eq!(current.rgba, options.color);
+            assert_eq!(
+                current.behaviour,
+                Behaviour::Spell {
+                    original_alpha: 0.8
+                }
+            );
+        }
+    }
+
     #[test]
     fn particle_light_cache_reuses_exact_blocks_and_fails_open_on_collisions() {
         let reads = std::cell::Cell::new(0);
@@ -5700,6 +5761,33 @@ mod tests {
         assert!((0.15 * 0.4 - 1e-6..=0.45 * 0.4 + 1e-6).contains(&s));
     }
     #[test]
+    fn legacy_trails_choose_a_lifetime_for_each_particle_from_the_level_random() {
+        let mut engine = ParticleEngine::new(Path::new(""), &HashMap::new(), &HashSet::new());
+        engine.seed_randoms(1, 42, 2);
+        for _ in 0..5 {
+            engine.create(
+                &ParticleOptions::trail([1.0, 2.0, 3.0], 0x7f3f1f, -1),
+                [0.0; 3],
+                [0.0; 3],
+            );
+        }
+        // java.util.Random(42).nextInt(40) + 10, as vanilla 1.21.3 TrailParticle.Provider does.
+        assert_eq!(
+            engine
+                .pending
+                .iter()
+                .map(|p| p.lifetime)
+                .collect::<Vec<_>>(),
+            [20, 13, 18, 14, 20]
+        );
+        engine.create(
+            &ParticleOptions::trail([1.0, 2.0, 3.0], 0x7f3f1f, 37),
+            [0.0; 3],
+            [0.0; 3],
+        );
+        assert_eq!(engine.pending.last().unwrap().lifetime, 37);
+    }
+    #[test]
     fn sizes_follow_vanilla_curves() {
         let mut r = LegacyRandom::new(2);
         let mut p = Particle::at(&mut r, ParticleType::Flame, [0.0; 3]);

crates/horizon-client-render/src/settings.rs

@@ -830,6 +830,7 @@ pub enum Opt {
     /// Horizon's controller settings (`horizon-controller.txt`).
     PadEnabled,
     PadVibration,
+    PadPlayInBackground,
     PadAdaptiveTriggers,
     PadLightbar,
     PadLookSensitivity,
@@ -845,6 +846,7 @@ pub enum Opt {
     PadTriggerThreshold,
     PadGlyphs,
     PadKeyboard,
+    PadGameplayGuide,
     /// `options.modelPart.*`: one skin layer (index into `options_file::MODEL_PARTS`).
     ModelPart(usize),
     /// 3D skin layers: the player's outer layer as extruded slabs.

crates/horizon-client-render/src/shader_ui.rs

@@ -644,6 +644,7 @@ impl ShaderUi {
                     hover,
                     focused,
                     held: self.dragging == Some(item),
+                    key: None,
                 };
                 shell::row(batch, atlas, &cols, y, &view);
             },

crates/horizon-client-render/src/streaming.rs

@@ -1126,18 +1126,29 @@ impl Streaming {
     pub fn lod_source(&self) -> Arc<dyn LodSource> {
         self.saves.clone()
     }
-    /// Resource packs reloaded (`LevelRenderer.allChanged`): mesh with the new
+    /// Resource packs reloaded (`LevelExtractor.allChanged`): mesh with the new
     /// models and sprites, and rebuild every loaded section. Meshes in flight
     /// were made with the old resources; their results are dropped.
     pub fn reload_resources(&mut self, world: &mut World, context: Arc<WorkerContext>) {
         *self.shared.context.write().unwrap() = context;
+        self.reload_sections(world);
+    }
+    /// `LevelExtractor.allChanged`: discard mesh work made before the reload and
+    /// rebuild every loaded, lit section.
+    pub fn reload_sections(&mut self, world: &mut World) {
         self.meshing.clear();
         self.compile_started.clear();
+        Self::mark_loaded_sections_dirty(world, &self.lit);
+    }
+    /// The resident sections `LevelExtractor.allChanged` queues again. An
+    /// unlit column will queue itself when its light job completes.
+    fn mark_loaded_sections_dirty(world: &mut World, lit: &FxHashSet<(i32, i32)>) {
         for &(x, z) in world.chunks.keys() {
-            if self.lit.contains(&(x, z)) {
-                for sy in 0..world.layout().sections() as i32 {
-                    world.dirty_sections.insert((x, sy, z));
-                }
+            if !lit.contains(&(x, z)) {
+                continue;
+            }
+            for sy in 0..world.layout().sections() as i32 {
+                world.dirty_sections.insert((x, sy, z));
             }
         }
     }
@@ -4462,3 +4473,38 @@ mod cover_tests {
         }
     }
 }
+
+#[cfg(test)]
+mod reload_tests {
+    use super::*;
+
+    #[test]
+    fn reload_marks_every_section_of_loaded_lit_columns() {
+        let mut world = World::new(horizon_world::registry::BlockStateId(0), 0);
+        world.chunks.insert((2, -3), Arc::new(Chunk::empty(2, -3)));
+        world.chunks.insert((4, 5), Arc::new(Chunk::empty(4, 5)));
+        let lit = FxHashSet::from_iter([(2, -3), (99, 99)]);
+
+        Streaming::mark_loaded_sections_dirty(&mut world, &lit);
+
+        let sections = world.layout().sections() as i32;
+        assert_eq!(world.dirty_sections.len(), sections as usize);
+        for sy in 0..sections {
+            assert!(world.dirty_sections.contains(&(2, sy, -3)));
+            assert!(!world.dirty_sections.contains(&(4, sy, 5)));
+        }
+    }
+
+    #[test]
+    fn reload_keeps_existing_work_and_ignores_unloaded_lit_columns() {
+        let mut world = World::new(horizon_world::registry::BlockStateId(0), 0);
+        world.chunks.insert((4, 5), Arc::new(Chunk::empty(4, 5)));
+        world.dirty_sections.insert((4, 3, 5));
+        let lit = FxHashSet::from_iter([(99, 99)]);
+
+        Streaming::mark_loaded_sections_dirty(&mut world, &lit);
+
+        assert_eq!(world.dirty_sections.len(), 1);
+        assert!(world.dirty_sections.contains(&(4, 3, 5)));
+    }
+}

crates/horizon-client-render/src/studio_ui.rs

@@ -88,6 +88,7 @@ impl SavedRecordingItem {
 #[derive(Clone, Debug, PartialEq)]
 pub enum StudioAction {
     None,
+    OpenReplay(PathBuf),
     OpenFolder,
     Refresh,
     Back,
@@ -103,6 +104,12 @@ pub struct StudioUi {
     pub record_dir: PathBuf,
 }
 
+/// A recording's row and the gap under it, in GUI pixels.
+const ROW_STEP: f32 = 40.0;
+const ROW_GAP: f32 = 4.0;
+/// The panel's margins above and below its rows.
+const LIST_MARGINS: f32 = 10.0;
+
 impl Default for StudioUi {
     fn default() -> Self {
         let dir = PathBuf::from("recordings");
@@ -270,18 +277,19 @@ impl StudioUi {
             );
         } else {
             // Render scrollable cards
-            let card_h = 36.0;
-            let card_gap = 4.0;
-            let row_step = card_h + card_gap;
-            let visible_cards = (panel_h / row_step).floor() as usize;
+            let card_h = ROW_STEP - ROW_GAP;
+            let row_step = ROW_STEP;
+            // Rows that fit whole between the panel's margins, as the loop below draws them.
+            let visible_cards = ((panel_h - LIST_MARGINS + ROW_GAP) / row_step).floor() as usize;
             let max_scroll =
                 (self.recordings.len().saturating_sub(visible_cards) as f32 * row_step).max(0.0);
             self.scroll = self.scroll.clamp(0.0, max_scroll);
 
             let card_w = panel_w - 12.0;
             let card_x = panel_x + 6.0;
-            let mut y = panel_y + 6.0 - (self.scroll % row_step);
-            let start_idx = (self.scroll / row_step) as usize;
+            // Whole rows: nothing here clips one that's partly scrolled off.
+            let mut y = panel_y + 6.0;
+            let start_idx = (self.scroll / row_step).round() as usize;
 
             for (idx, item) in self.recordings.iter().enumerate().skip(start_idx) {
                 if y + card_h > panel_y + panel_h - 4.0 {
@@ -289,6 +297,8 @@ impl StudioUi {
                 }
 
                 let rect = [card_x, y, card_w, card_h];
+                crate::widgets::record_as(&item.title, rect, true, crate::widgets::Kind::Row);
+                crate::widgets::target_as(rect, crate::widgets::Kind::Row);
                 let is_hovered = ui::hovered(cursor, card_x, y, card_w, card_h);
                 let is_selected = self.selected == Some(idx);
 
@@ -334,6 +344,12 @@ impl StudioUi {
                 y += row_step;
             }
 
+            crate::widgets::scroll_area(
+                [panel_x, panel_y, panel_w, panel_h],
+                self.scroll,
+                max_scroll,
+            );
+
             // Scrollbar track & thumb if scrollable
             if max_scroll > 0.0 {
                 let track_x = panel_x + panel_w - 4.0;
@@ -357,35 +373,35 @@ impl StudioUi {
         // Button 1: Open Folder (Left)
         let f_btn = [panel_x, btn_y, 130.0, btn_h];
         let f_hover = ui::hovered(cursor, f_btn[0], f_btn[1], f_btn[2], f_btn[3]);
-        style::button(
-            batch,
-            atlas,
-            f_btn,
-            &Text::tr("horizon.studio.open_folder", &[]),
-            (f_hover, true, false),
-        );
+        let label = Text::tr("horizon.studio.open_folder", &[]);
+        crate::widgets::record(&label.plain(), f_btn, true);
+        style::button(batch, atlas, f_btn, &label, (f_hover, true, false));
 
         // Button 2: Refresh (Center-Left)
         let r_btn = [panel_x + 136.0, btn_y, 65.0, btn_h];
         let r_hover = ui::hovered(cursor, r_btn[0], r_btn[1], r_btn[2], r_btn[3]);
+        let label = Text::tr("horizon.studio.refresh", &[]);
+        crate::widgets::record(&label.plain(), r_btn, true);
+        style::button(batch, atlas, r_btn, &label, (r_hover, true, false));
+
+        // Button 3: Open the selected recording for playback.
+        let e_btn = [panel_x + panel_w - 180.0, btn_y, 110.0, btn_h];
+        let e_hover = ui::hovered(cursor, e_btn[0], e_btn[1], e_btn[2], e_btn[3]);
         style::button(
             batch,
             atlas,
-            r_btn,
-            &Text::tr("horizon.studio.refresh", &[]),
-            (r_hover, true, false),
+            e_btn,
+            &Text::tr("horizon.studio.open_replay", &[]),
+            (e_hover, true, false),
         );
 
         // Button 3: Done / Back (Right)
         let d_btn = [panel_x + panel_w - 64.0, btn_y, 64.0, btn_h];
         let d_hover = ui::hovered(cursor, d_btn[0], d_btn[1], d_btn[2], d_btn[3]);
-        style::button(
-            batch,
-            atlas,
-            d_btn,
-            &Text::tr("gui.done", &[]),
-            (d_hover, true, false),
-        );
+        let label = Text::tr("gui.done", &[]);
+        crate::widgets::record(&label.plain(), d_btn, true);
+        style::button(batch, atlas, d_btn, &label, (d_hover, true, false));
+        crate::widgets::declare_action(crate::widgets::Action::Done, d_btn, true);
     }
 
     /// Process mouse click on the Studio Browser screen.
@@ -411,20 +427,32 @@ impl StudioUi {
             return StudioAction::Refresh;
         }
 
-        // Button 3: Done
+        // Button 3: Open Replay
+        let e_btn = [panel_x + panel_w - 180.0, btn_y, 110.0, btn_h];
+        if ui::hovered(cursor, e_btn[0], e_btn[1], e_btn[2], e_btn[3]) {
+            if let Some(idx) = self.selected
+                && let Some(item) = self.recordings.get(idx)
+            {
+                return StudioAction::OpenReplay(item.path.clone());
+            } else if let Some(item) = self.recordings.first() {
+                self.selected = Some(0);
+                return StudioAction::OpenReplay(item.path.clone());
+            }
+        }
+
+        // Button 4: Done
         let d_btn = [panel_x + panel_w - 64.0, btn_y, 64.0, btn_h];
         if ui::hovered(cursor, d_btn[0], d_btn[1], d_btn[2], d_btn[3]) {
             return StudioAction::Back;
         }
 
         // Card clicks
-        let card_h = 36.0;
-        let card_gap = 4.0;
-        let row_step = card_h + card_gap;
+        let card_h = ROW_STEP - ROW_GAP;
+        let row_step = ROW_STEP;
         let card_w = panel_w - 12.0;
         let card_x = panel_x + 6.0;
-        let start_idx = (self.scroll / row_step) as usize;
-        let mut y = panel_y + 6.0 - (self.scroll % row_step);
+        let start_idx = (self.scroll / row_step).round() as usize;
+        let mut y = panel_y + 6.0;
 
         for (idx, _) in self.recordings.iter().enumerate().skip(start_idx) {
             if y + card_h > panel_y + panel_h - 4.0 {
@@ -444,7 +472,8 @@ impl StudioUi {
 
     /// Scroll list by mouse wheel delta.
     pub fn wheel(&mut self, amount: f32) {
-        self.scroll = (self.scroll - amount * 24.0).max(0.0);
+        // A notch is a row, as a focus step needs (`gamepad::list_step`).
+        self.scroll = (self.scroll - amount * ROW_STEP).max(0.0);
     }
 }
 
@@ -516,6 +545,11 @@ mod tests {
         assert_eq!(action, StudioAction::None);
         assert_eq!(ui.selected, Some(0));
 
+        // Click the bottom-bar Open Replay button.
+        // Panel width = 387, panel_x = 20, button x = 227..337, y = 692..712.
+        let open_replay_action = ui.click((280.0, 700.0), (427.0, 720.0));
+        assert!(matches!(open_replay_action, StudioAction::OpenReplay(_)));
+
         // Clean up
         let _ = fs::remove_dir_all(&temp_dir);
     }
@@ -527,6 +561,6 @@ mod tests {
         assert_eq!(ui.scroll, 0.0); // clamped at 0
         ui.scroll = 100.0;
         ui.wheel(1.0);
-        assert_eq!(ui.scroll, 76.0);
+        assert_eq!(ui.scroll, 100.0 - ROW_STEP);
     }
 }

crates/horizon-client-render/src/terrain.wgsl

@@ -723,6 +723,72 @@ fn solid_finish_at(in: TerrainOut, texel: vec4<f32>, color: vec4<f32>, du: vec2<
     return apply_fog(color, in.spherical, in.cylindrical);
 }
 
+// Native still-fluid boxes use block sprites and lightmap without terrain AO/emission
+// packing or entity-model diffuse shading. The absolute sprite layer occupies glint UV x.
+struct NativeFluidOut {
+    @builtin(position) clip: vec4<f32>,
+    @location(0) uv: vec2<f32>,
+    @location(1) color: vec4<f32>,
+    @location(2) @interpolate(flat) sprite: u32,
+    @location(3) spherical: f32,
+    @location(4) cylindrical: f32,
+}
+@vertex fn vs_native_fluid(@location(0) position: vec3<f32>, @location(1) uv: vec2<f32>,
+    @location(3) color: vec4<f32>, @location(4) light: vec4<u32>,
+    @location(6) sprite: vec2<f32>) -> NativeFluidOut {
+    let block = max(f32(light.y), dynamic_block_light(position));
+    var lit = color * sample_lightmap(f32(light.x) / 16.0, block / 16.0);
+    if globals.colored_count.x > 0u {
+        lit = vec4(min(lit.rgb + color.rgb * native_colored_light(position), vec3(1.0)), lit.a);
+    }
+    return NativeFluidOut(globals.view_proj * vec4(position, 1.0), uv, lit, u32(sprite.x),
+        length(position), max(length(position.xz), abs(position.y)));
+}
+@fragment fn fs_native_fluid(in: NativeFluidOut) -> @location(0) vec4<f32> {
+    // The source translucent shader has no alpha discard; transparent texels write depth too.
+    let color = sprite_grad(in.uv, in.sprite, dpdx(in.uv), dpdy(in.uv)) * in.color;
+    return apply_fog(color, in.spherical, in.cylindrical);
+}
+
+// Native terrain models retain floating-point transformed normals. Fullbright still receives
+// entity directional shading; the material's alpha test and mip policy are independent.
+// Diffuse/normal policy: Flywheel 1.0.6, copyright2021-2024 Jozufozu (MIT);
+// full permission/warranty notice in THIRD_PARTY_NOTICES.md.
+override NATIVE_MODEL_ALPHA_CUTOFF: f32 = 0.0;
+struct NativeModelOut {
+    @builtin(position) clip: vec4<f32>,
+    @location(0) uv: vec2<f32>,
+    @location(1) color: vec4<f32>,
+    @location(2) @interpolate(flat) sprite: u32,
+    @location(3) spherical: f32,
+    @location(4) cylindrical: f32,
+    @location(5) normal: vec3<f32>,
+}
+@vertex fn vs_native_model(@location(0) position: vec3<f32>, @location(1) uv: vec2<f32>,
+    @location(2) layer: u32, @location(3) color: vec4<f32>, @location(4) light: vec4<u32>,
+    @location(5) normal_z: u32, @location(6) normal_xy: vec2<f32>) -> NativeModelOut {
+    let block = max(f32(light.y), dynamic_block_light(position));
+    var lit = color * sample_lightmap(f32(light.x) / 16.0, block / 16.0);
+    if globals.colored_count.x > 0u {
+        lit = vec4(min(lit.rgb + color.rgb * native_colored_light(position), vec3(1.0)), lit.a);
+    }
+    return NativeModelOut(globals.view_proj * vec4(position, 1.0), uv, lit, layer >> 16u,
+        length(position), max(length(position.xz), abs(position.y)),
+        vec3(normal_xy, bitcast<f32>(normal_z)));
+}
+@fragment fn fs_native_model(in: NativeModelOut) -> @location(0) vec4<f32> {
+    var color = sprite_grad(in.uv, in.sprite, dpdx(in.uv), dpdy(in.uv)) * in.color;
+    if NATIVE_MODEL_ALPHA_CUTOFF > 0.0 && color.a < NATIVE_MODEL_ALPHA_CUTOFF { discard; }
+    if any(in.normal != vec3(0.0)) {
+        let light0 = normalize(vec3(0.2, 1.0, -0.7));
+        let light1 = normalize(vec3(-0.2, select(1.0, -1.0, globals.time.y > 0.5), 0.7));
+        let shade = min(1.0, (max(0.0, dot(light0, in.normal))
+            + max(0.0, dot(light1, in.normal))) * 0.6 + 0.4);
+        color = vec4(color.rgb * shade, color.a);
+    }
+    return apply_fog(color, in.spherical, in.cylindrical);
+}
+
 // Sky (SkyRenderer): the 10-vertex sky disc fan at y = 16 (radius 512) in
 // the sky colour with sky fog (sky.fsh: fog 0..FogSkyEnd on the spherical
 // distance, a step at FogSkyEnd on the cylindrical one), evaluated per pixel

crates/horizon-client-render/src/terrain_model.rs

@@ -0,0 +1,215 @@
+//! Native terrain-sheet models with explicit material and UV policy.
+use crate::{gfx, mesher::Vertex, models::catalog::BakedFace};
+use glam::{Mat3, Mat4, Vec3};
+use horizon_assets::bake::RenderType;
+fn same_sprite(left: &str, right: &str) -> bool {
+    left.strip_prefix("minecraft:").unwrap_or(left)
+        == right.strip_prefix("minecraft:").unwrap_or(right)
+}
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
+pub enum NativeModelMaterial {
+    /// Use each baked quad's material; unsupported translucent/tripwire quads fail the whole call.
+    #[default]
+    Model,
+    Solid,
+    Cutout,
+    CutoutMipped,
+}
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
+pub enum NativeModelShade {
+    /// Respect the baked quad's directional-shading flag.
+    #[default]
+    Model,
+    Off,
+    /// The level's two entity light directions, even at full block/sky light.
+    Entity,
+}
+
+/// Transform UVs only on the explicitly named original sprite, in unit-sprite coordinates.
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub struct NativeModelUvShift<'a> {
+    pub source_sprite: &'a str,
+    pub target_sprite: &'a str,
+    pub scale: [f32; 2],
+    pub offset: [f32; 2],
+}
+
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub struct NativeModelRenderOptions<'a> {
+    pub material: NativeModelMaterial,
+    pub shade: NativeModelShade,
+    pub uv_shift: Option<NativeModelUvShift<'a>>,
+    /// Optional compatibility policy applied toward each face's UV bounds center before shifting.
+    /// Zero retains the baked UVs. For an older JSON FaceBakery use its actual atlas shrink ratio;
+    /// OBJ loaders that do not shrink UVs must keep zero.
+    pub uv_shrink_ratio: f32,
+    /// RGB multiplier on quads with a tint index; other quads keep their baked color.
+    pub tint: u32,
+}
+impl Default for NativeModelRenderOptions<'_> {
+    fn default() -> Self {
+        Self {
+            material: NativeModelMaterial::Model,
+            shade: NativeModelShade::Model,
+            uv_shift: None,
+            uv_shrink_ratio: 0.0,
+            tint: 0xff_ffff,
+        }
+    }
+}
+
+fn overlay(face: &BakedFace, policy: NativeModelMaterial) -> Option<u32> {
+    use NativeModelMaterial as M;
+    Some(match policy {
+        M::Solid => gfx::TERRAIN_MODEL_SOLID_OVERLAY,
+        M::Cutout => gfx::TERRAIN_MODEL_CUTOUT_OVERLAY,
+        M::CutoutMipped => gfx::TERRAIN_MODEL_CUTOUT_MIPPED_OVERLAY,
+        M::Model => match face.quad.render_type.unwrap_or(RenderType::Solid) {
+            RenderType::Solid if !face.quad.material.force_translucent => {
+                gfx::TERRAIN_MODEL_SOLID_OVERLAY
+            }
+            RenderType::Cutout => gfx::TERRAIN_MODEL_CUTOUT_OVERLAY,
+            RenderType::CutoutMipped => gfx::TERRAIN_MODEL_CUTOUT_MIPPED_OVERLAY,
+            _ => return None,
+        },
+    })
+}
+
+/// A whole draw validates before its first vertex. No temporary geometry allocation, resource
+/// scans, partial fallback or change to the ordinary native model helper.
+pub fn draw_model(
+    faces: &[BakedFace],
+    pose: Mat4,
+    light: u32,
+    options: NativeModelRenderOptions<'_>,
+    sprite: impl Fn(&str) -> Option<u32>,
+    mut emit: impl FnMut(Vertex),
+) -> bool {
+    if !pose.is_finite()
+        || !options.uv_shrink_ratio.is_finite()
+        || !(0.0..=1.0).contains(&options.uv_shrink_ratio)
+    {
+        return false;
+    }
+    let normal_pose = Mat3::from_mat4(pose).inverse().transpose();
+    if !normal_pose.is_finite() {
+        return false;
+    }
+    let shift = match options.uv_shift {
+        Some(shift) => {
+            if shift
+                .scale
+                .iter()
+                .chain(&shift.offset)
+                .any(|v| !v.is_finite())
+            {
+                return false;
+            }
+            let (Some(source), Some(target)) =
+                (sprite(shift.source_sprite), sprite(shift.target_sprite))
+            else {
+                return false;
+            };
+            if source > u16::MAX.into() || target > u16::MAX.into() {
+                return false;
+            }
+            if !faces
+                .iter()
+                .any(|face| same_sprite(&face.quad.material.sprite, shift.source_sprite))
+            {
+                return false;
+            }
+            Some((source, target, shift))
+        }
+        None => None,
+    };
+    let vertices = |face: &BakedFace| -> Option<[Vertex; 4]> {
+        let quad = &face.quad;
+        let overlay = overlay(face, options.material)?;
+        let mut layer = sprite(&quad.material.sprite)?;
+        if layer > u16::MAX.into() || layer != face.layer {
+            return None;
+        }
+        let mut uv = quad.uv;
+        if uv.iter().flatten().any(|v| !v.is_finite()) {
+            return None;
+        }
+        if options.uv_shrink_ratio != 0.0 {
+            let center = std::array::from_fn::<_, 2, _>(|i| {
+                let min = uv.iter().map(|p| p[i]).fold(f32::INFINITY, f32::min);
+                let max = uv.iter().map(|p| p[i]).fold(f32::NEG_INFINITY, f32::max);
+                (min + min + max + max) / 4.0
+            });
+            for p in &mut uv {
+                *p = std::array::from_fn(|i| p[i] + options.uv_shrink_ratio * (center[i] - p[i]));
+            }
+        }
+        if let Some((_, target, shift)) = shift
+            && same_sprite(&quad.material.sprite, shift.source_sprite)
+        {
+            layer = target;
+            for p in &mut uv {
+                *p = std::array::from_fn(|i| p[i] * shift.scale[i] + shift.offset[i]);
+            }
+        }
+        let shaded = match options.shade {
+            NativeModelShade::Model => quad.shade,
+            NativeModelShade::Off => false,
+            NativeModelShade::Entity => true,
+        };
+        let normal = if shaded {
+            let p = quad.positions.map(Vec3::from_array);
+            let n = (p[1] - p[0]).cross(p[2] - p[0]).normalize_or_zero();
+            // Baked model normals are signed bytes before the instance's normal matrix.
+            // Keep the transformed normal as floats; quantizing it again changes rotated faces.
+            let n = n.map(|v| ((v * 127.0) as i8) as f32 / 127.0);
+            (normal_pose * n).normalize_or_zero()
+        } else {
+            Vec3::ZERO
+        };
+        let normal_bits = normal.z.to_ne_bytes().map(|b| b as i8);
+        let argb = quad.color.map_or(u32::MAX, |v| v as u32);
+        let mut color = (argb & 0xff00_ff00) | (argb >> 16 & 0xff) | (argb & 0xff) << 16;
+        if quad.tint_index >= 0 {
+            let tint = options.tint;
+            let rgb = (tint >> 16 & 0xff) | (tint & 0xff00) | (tint & 0xff) << 16;
+            color = (color & 0xff00_0000)
+                | ((color & 0xff) * (rgb & 0xff) / 255)
+                | (((color >> 8 & 0xff) * (rgb >> 8 & 0xff) / 255) << 8)
+                | (((color >> 16 & 0xff) * (rgb >> 16 & 0xff) / 255) << 16);
+        }
+        let light = (light & 0xff).max(u32::from(quad.light[1]) * 16)
+            | ((light >> 8 & 0xff).max(u32::from(quad.light[0].max(quad.light_emission)) * 16)
+                << 8);
+        let positions = quad
+            .positions
+            .map(|p| pose.transform_point3(Vec3::from_array(p)));
+        if positions.iter().any(|p| !p.is_finite()) || uv.iter().flatten().any(|v| !v.is_finite()) {
+            return None;
+        }
+        Some(std::array::from_fn(|i| Vertex {
+            pos: positions[i].to_array(),
+            uv: uv[i],
+            layer: overlay | layer << 16,
+            color,
+            light,
+            normal: normal_bits,
+            glint_uv: [normal.x, normal.y],
+        }))
+    };
+    if faces.iter().any(|face| vertices(face).is_none()) {
+        return false;
+    }
+    for face in faces {
+        for vertex in vertices(face).expect("validated immutable model") {
+            emit(vertex);
+        }
+    }
+    true
+}
+
+#[cfg(test)]
+#[path = "terrain_model_tests.rs"]
+mod tests;

crates/horizon-client-render/src/terrain_model_tests.rs

@@ -0,0 +1,171 @@
+use super::*;
+use horizon_assets::{
+    bake::bake_flat_face,
+    model::{Direction, Material},
+};
+
+fn face() -> BakedFace {
+    BakedFace::new(
+        bake_flat_face(
+            [0.0; 3],
+            [16.0; 3],
+            [0.0, 0.0, 16.0, 16.0],
+            Direction::South,
+            Material {
+                sprite: "test:source".into(),
+                force_translucent: false,
+            },
+            -1,
+        )
+        .unwrap(),
+        7,
+        true,
+        false,
+        None,
+    )
+}
+fn sprite(name: &str) -> Option<u32> {
+    match name {
+        "test:source" => Some(7),
+        "test:target" => Some(11),
+        _ => None,
+    }
+}
+fn draw(
+    faces: &[BakedFace],
+    pose: Mat4,
+    options: NativeModelRenderOptions<'_>,
+) -> (bool, Vec<Vertex>) {
+    let mut output = Vec::new();
+    let accepted = draw_model(faces, pose, 0xf0f0, options, sprite, |v| output.push(v));
+    (accepted, output)
+}
+#[test]
+fn late_unknown_material_or_sprite_rejects_the_whole_model() {
+    let first = face();
+    let mut second = face();
+    second.quad.render_type = Some(RenderType::Unsupported);
+    let mut faces = [first, second];
+    let (accepted, output) = draw(&faces, Mat4::IDENTITY, Default::default());
+    assert!(!accepted);
+    assert!(output.is_empty());
+    let (accepted, output) = draw(
+        &faces,
+        Mat4::IDENTITY,
+        NativeModelRenderOptions {
+            material: NativeModelMaterial::Cutout,
+            ..Default::default()
+        },
+    );
+    assert!(accepted);
+    assert_eq!(output.len(), 8);
+    faces[1].quad.material.sprite = "test:missing".into();
+    let (accepted, output) = draw(&faces, Mat4::IDENTITY, Default::default());
+    assert!(!accepted);
+    assert!(output.is_empty());
+}
+#[test]
+fn exact_sprite_shift_and_explicit_json_shrink_precede_array_mapping() {
+    let options = NativeModelRenderOptions {
+        uv_shrink_ratio: 4.0 / 2048.0,
+        uv_shift: Some(NativeModelUvShift {
+            source_sprite: "test:source",
+            target_sprite: "test:target",
+            scale: [0.5; 2],
+            offset: [0.25, 0.125],
+        }),
+        ..Default::default()
+    };
+    let (accepted, output) = draw(&[face()], Mat4::IDENTITY, options);
+    assert!(accepted);
+    assert_eq!(output[0].uv, [0.25048828, 0.12548828]);
+    assert_eq!(output[2].uv, [0.7495117, 0.6245117]);
+    assert!(output.iter().all(|v| v.layer >> 16 == 11));
+    let (accepted, output) = draw(
+        &[face()],
+        Mat4::IDENTITY,
+        NativeModelRenderOptions {
+            uv_shift: Some(NativeModelUvShift {
+                source_sprite: "test:target",
+                target_sprite: "test:source",
+                ..options.uv_shift.unwrap()
+            }),
+            ..options
+        },
+    );
+    assert!(!accepted);
+    assert!(output.is_empty());
+}
+#[test]
+fn transformed_slope_normal_stays_float_and_fullbright_keeps_shading() {
+    let mut face = face();
+    face.quad.positions = [
+        [0.0, 0.0, 0.0],
+        [0.0, 1.0, 1.0],
+        [1.0, 1.0, 1.0],
+        [1.0, 0.0, 0.0],
+    ];
+    let pose = Mat4::from_rotation_y(0.372) * Mat4::from_scale(Vec3::new(-2.0, 3.0, 1.0));
+    let (accepted, output) = draw(&[face], pose, Default::default());
+    assert!(accepted);
+    let normal = Vec3::new(
+        output[0].glint_uv[0],
+        output[0].glint_uv[1],
+        f32::from_ne_bytes(output[0].normal.map(|v| v as u8)),
+    );
+    assert!((normal.length() - 1.0).abs() < 1e-6);
+    assert!((normal.y - 0.31622776).abs() < 1e-6);
+    assert!((normal.x + 0.3448316).abs() < 1e-5, "{normal:?}");
+    assert_eq!(output[0].light, 0xf0f0);
+    assert_eq!(output[0].color, u32::MAX);
+    // Float payload, not a second signed-byte normal quantization.
+    assert_ne!(normal.y, (normal.y * 127.0) as i8 as f32 / 127.0);
+}
+#[test]
+fn invalid_shift_and_singular_pose_emit_nothing() {
+    let options = NativeModelRenderOptions {
+        uv_shrink_ratio: f32::NAN,
+        ..Default::default()
+    };
+    let (ok, output) = draw(&[face()], Mat4::IDENTITY, options);
+    assert!(!ok);
+    assert!(output.is_empty());
+    let (ok, output) = draw(
+        &[face()],
+        Mat4::from_scale(Vec3::new(1.0, 0.0, 1.0)),
+        Default::default(),
+    );
+    assert!(!ok);
+    assert!(output.is_empty());
+}
+
+#[test]
+fn a_deduplicated_array_layer_is_not_the_same_named_source_sprite() {
+    let mut alias = face();
+    alias.quad.material.sprite = "test:alias".into();
+    let mut output = Vec::new();
+    assert!(draw_model(
+        &[face(), alias],
+        Mat4::IDENTITY,
+        0xf0f0,
+        NativeModelRenderOptions {
+            uv_shift: Some(NativeModelUvShift {
+                source_sprite: "test:source",
+                target_sprite: "test:target",
+                scale: [0.5; 2],
+                offset: [0.25; 2]
+            }),
+            ..Default::default()
+        },
+        |name| if name == "test:alias" {
+            Some(7)
+        } else {
+            sprite(name)
+        },
+        |v| output.push(v)
+    ));
+    assert_eq!(output[0].layer >> 16, 11);
+    assert_eq!(output[4].layer >> 16, 7);
+    assert_eq!(output[4].uv, [0.0, 0.0]);
+    assert_eq!(output[6].uv, [1.0, 1.0]);
+}

crates/horizon-client-render/src/ui.rs

@@ -134,6 +134,10 @@ fn scaling(sprite: &str, r: &Rect) -> NineSlice {
         width: r.w,
         height: r.h,
         border: match sprite {
+            "horizon/jei/button_enabled_v2"
+            | "horizon/jei/button_disabled_v2"
+            | "horizon/jei/button_highlight_v2" => [6; 4],
+            "horizon/jei/search_background_v2" => [6; 4],
             "gui/sprites/widget/button"
             | "gui/sprites/widget/button_highlighted"
             | "gui/sprites/widget/button_disabled" => [3; 4],
@@ -1636,10 +1640,19 @@ impl EditBox {
     }
     /// Draw the field; `format` styles the visible text (command colouring).
     pub fn draw(&mut self, batch: &mut HudBatch, atlas: &HudAtlas, format: Option<&Text>) {
+        self.draw_with_skin(batch, atlas, format, None);
+    }
+
+    pub fn draw_with_skin(
+        &mut self,
+        batch: &mut HudBatch,
+        atlas: &HudAtlas,
+        format: Option<&Text>,
+        skin: Option<&str>,
+    ) {
         self.layout(atlas);
         crate::widgets::target_as(
-            self.frame
-                .unwrap_or([self.x, self.y, self.width, self.height]),
+            [self.x, self.y, self.width, self.height],
             crate::widgets::Kind::Field,
         );
         crate::widgets::narratable(|| {
@@ -1651,11 +1664,11 @@ impl EditBox {
             .focused(self.focused)
         });
         if self.bordered {
-            let sprite = if self.focused {
+            let sprite = skin.unwrap_or(if self.focused {
                 "gui/sprites/widget/text_field_highlighted"
             } else {
                 "gui/sprites/widget/text_field"
-            };
+            });
             nine_slice(
                 batch,
                 atlas,