Merge remote-tracking branch 'origin/main' into layers/packs-entity

# Conflicts:
#	crates/horizon-client/src/client_lib.rs

.github/trusted-reviewers.txt

@@ -13,4 +13,3 @@
 87152661 rdbtCVS         # added by Ludovic, 2026-10-27
 84875247 Online5277      # added by Ludovic, 2026-10-27 (his top three by merged pull requests)
 86072227 levzzz5154      # added by Ludovic, 2026-10-28 (Horizon Team; author of horizon-mixins)
-169198624 itarqos5        # added by Ludovic, 2026-11-08 (Discord Literal; Horizon Team)

AGENTS.md

@@ -75,6 +75,7 @@ Game workspace (root `Cargo.toml`); `launcher/` and `crates/horizon-telemetry-se
 | `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-pack-options` | A resource pack's own options as the game lists and keeps them (entries, controls, values, presets), whatever pack format declares them; engine, no dependencies |
 | `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 |

CONTRIBUTING.md

@@ -198,3 +198,5 @@ new pushes, we add it again.
 
 [Discord](https://discord.gg/playhorizon) for questions and ideas, [issues](https://github.com/horizon-rust/horizon/issues)
 for bugs. To take something on, `/claim` its issue ([above](#claim-before-you-start)).
+
+How Horizon is run, and how people join the Team or lead a group: [GOVERNANCE.md](GOVERNANCE.md).

Cargo.lock

@@ -1590,6 +1590,7 @@ dependencies = [
  "horizon-items",
  "horizon-narrator",
  "horizon-optifine",
+ "horizon-pack-options",
  "horizon-polytone",
  "horizon-protocol",
  "horizon-shader-api",
@@ -1650,6 +1651,15 @@ dependencies = [
  "ureq",
 ]
 
+[[package]]
+name = "horizon-discord"
+version = "0.1.0"
+dependencies = [
+ "horizon-platform",
+ "log",
+ "serde_json",
+]
+
 [[package]]
 name = "horizon-dualsense"
 version = "0.1.0"
@@ -1793,14 +1803,25 @@ dependencies = [
 name = "horizon-official"
 version = "0.1.0"
 dependencies = [
+ "horizon-discord",
  "horizon-friends",
  "horizon-game",
  "horizon-heartbeat",
+ "horizon-official-servers",
  "horizon-platform",
  "log",
  "winresource",
 ]
 
+[[package]]
+name = "horizon-official-servers"
+version = "0.1.0"
+dependencies = [
+ "horizon-addresses",
+ "horizon-platform",
+ "log",
+]
+
 [[package]]
 name = "horizon-optifine"
 version = "0.1.0"
@@ -1811,6 +1832,10 @@ dependencies = [
  "regex",
 ]
 
+[[package]]
+name = "horizon-pack-options"
+version = "0.1.0"
+
 [[package]]
 name = "horizon-platform"
 version = "0.1.0"
@@ -1828,6 +1853,7 @@ dependencies = [
 name = "horizon-polytone"
 version = "0.1.0"
 dependencies = [
+ "horizon-pack-options",
  "log",
  "regex",
  "serde_json",

Cargo.toml

@@ -34,6 +34,8 @@ members = [
     "crates/horizon-game",
     "crates/horizon-official",
     "crates/horizon-heartbeat",
+    "crates/horizon-discord",
+    "crates/horizon-official-servers",
     "crates/horizon-bench",
     "crates/horizon-friends",
     "crates/horizon-relay",
@@ -45,6 +47,7 @@ members = [
     "crates/horizon-shaders",
     "crates/horizon-optifine",
     "crates/horizon-polytone",
+    "crates/horizon-pack-options",
     "crates/horizon-shader-api",
     "crates/horizon-release-sign",
     "crates/horizon-mod-deps",

GOVERNANCE.md

@@ -0,0 +1,483 @@
+# Horizon governance
+
+> Adopted 2026-11-09 by the founder as his last decision as head of the project. It takes effect when he
+> announces that he is stepping down. From then on only the council changes it, by a 2/3 poll (section 15).
+
+Horizon has no boss. A **council of equals** decides by polls. **Theme groups** do the work in their areas, each
+with a **lead**. The **Horizon Team** reviews and merges code. **Moderators** keep the Discord server and the
+official server safe. Every role of trust is earned with work the project can measure, and it ends when that work
+stops.
+
+## Contents
+
+1. [Principles](#1-principles)
+2. [The levels at a glance](#2-the-levels-at-a-glance)
+3. [Each level in detail](#3-each-level-in-detail)
+4. [The council and its polls](#4-the-council-and-its-polls)
+5. [The selection filter](#5-the-selection-filter)
+6. [Theme groups](#6-theme-groups)
+7. [Moderation and appeals](#7-moderation-and-appeals)
+8. [Conflicts and hard cases](#8-conflicts-and-hard-cases)
+9. [The age rule (18+)](#9-the-age-rule-18)
+10. [The agents](#10-the-agents)
+11. [Accounts and the handover path](#11-accounts-and-the-handover-path)
+12. [Money](#12-money)
+13. [Transparency](#13-transparency)
+14. [Rules that are never voted on](#14-rules-that-are-never-voted-on)
+15. [Changing this document](#15-changing-this-document)
+
+## 1. Principles
+
+- **Equals.** Every council member has one vote. Nobody, the founder included, stands above the others.
+- **The founder.** Ludovic keeps the title of **Founder**: his role stays at the top of the member list and he is
+  credited as Horizon's founder everywhere. The title is symbolic. It carries no extra vote or power: on the council
+  he counts exactly like every other member.
+- **Evidence, not popularity.** You get a role by doing the work first. Kira measures that work: merged pull
+  requests, reviews, triage, support answers and days active. A vote then confirms it.
+- **Small, clear powers.** Each role can do a short, written list of things. Anything else goes to the council.
+- **Roles are on loan.** Every role has a 30-day probation and an inactivity rule. Stepping down for inactivity is
+  not a sanction, and you can come back.
+- **Public by default.** Polls, results and rules are public. Only matters about a person stay private, and even then
+  the result is published.
+- **18+ for roles of trust** (section 9).
+- **Mojang's and Microsoft's rules come first.** They are never put to a vote (section 14).
+
+## 2. The levels at a glance
+
+From the most open level to the most trusted. A person can hold several levels at once: a group lead can also be on
+the Horizon Team, for example.
+
+| Level | What it can do | How you get in | How you leave | 18+ |
+| --- | --- | --- | --- | --- |
+| **Member** | Play, chat, report bugs, suggest ideas, open issues and pull requests, pick group roles | Join the Discord server or the GitHub repo | Leave, or get banned | No |
+| **Contributor** (⛏️ Iron, 🥇 Gold, 💎 Diamond, 🟪 Netherite ranks) | Write in #contributors; `/claim` issues; nominate people for group lead (if active in that group) | One merged pull request in a public horizon-rust repo, linked with `/link-github` and `/verify-github`. Ranks come from merged pull requests: 10, 40, 100 and 200 | Contributor status and ranks stay | No |
+| **Group member** | Read and write in the group's channel; get the group's pings; take part in the group's advisory poll on its lead | Pick the group's role in Channels & Roles, or with `/groups` | Remove the role | No |
+| **🤝 Support** | Answer and close posts in #horizon-support | `/apply`; vote of the mods and the Team (as today) | Resign, 30 days inactive, or removed by the Chief of Mods or the council | No |
+| **🛡️ Moderator** | Time out, delete messages, manage threads, quarantine. No bans | `/apply`, then the selection filter; mods' vote; the council may object within 24 h | Resign, 30 days inactive, suspended by the Chief of Mods, removed by a council poll (simple majority) | **Yes** |
+| **🛡️ Chief of Mods** | A moderator's powers, plus bans; leads the mods; suspends a mod at once pending the council | Council poll (simple majority), from the mods with at least 30 days | Resign, 30 days inactive, council poll (simple majority) | **Yes** |
+| **🧭 Group lead** | Decides inside the group's topic (section 6); manages the group's channel; triage on the group's GitHub issues | Nomination, the filter, a 24 h public discussion with an advisory group poll, then a council poll (simple majority); 30 days probation | Resign, 30 days inactive (automatic), council poll (simple majority); confirmed again every 6 months | **Yes** |
+| **🌌 Horizon Team** | Review and merge pull requests (GitHub `horizon-team`, write access); `/nightly` and triage commands (trusted reviewers); #horizon-team | Nomination, the filter, a 24 h public discussion, then a council poll (2/3); 30 days probation | Resign, 60 days without a merge or review (automatic), council poll (2/3, without the person) | **Yes** |
+| **🏛️ Council** | Decides everything else by poll (section 4); bans; emergency actions by any 2 members | Nominated by a council member, the filter, a 24 h public discussion, then a council poll (2/3); 30 days probation | Resign, inactivity (section 5.5), council poll (2/3, without the person) | **Yes** |
+
+**The account holder** isn't a level. The founder (Ludovic) still holds the project's accounts (GitHub organisation
+owner, Discord server owner, the Microsoft app approved by Mojang, the domains, Railway, money). He carries out the
+council's decisions on them and hands them over step by step (section 11). As a council member he has one vote,
+like everyone else.
+
+## 3. Each level in detail
+
+### Member
+
+Anyone in the Discord server or on GitHub. Members follow the server rules and Horizon's
+[contributing guide](CONTRIBUTING.md). They can propose anything: an idea in #horizon-ideas, a bug in #horizon-bugs,
+an issue or a pull request on GitHub, or a request for a council poll (any council member can pick it up).
+
+### Contributor
+
+- **Discord:** the 🛠️ Contributor role writes in #contributors and in the threads of #polls-and-decisions. A rank
+  role (⛏️ Iron at 10 merged pull requests, 🥇 Gold at 40, 💎 Diamond at 100, 🟪 Netherite at 200, counted over every
+  public horizon-rust repo) shows how much has been merged. Ranks only go up.
+- **GitHub:** no repository role. Anyone can `/claim` and `/unclaim` their own issues.
+- **Alone:** their own work.
+
+### Group member
+
+Each theme group (section 6) has a role that anyone can pick and drop. It opens the group's channel and receives the
+group's pings. Picking a role grants no power. A group member counts as **active in the group** when Kira has seen at
+least one counted action in the group's area (section 5.1) in the last 60 days. Only active group members can
+nominate a lead or vote in the group's advisory poll.
+
+### 🤝 Support
+
+Unchanged: Support members help players in #horizon-support. They answer every post there and mark posts solved.
+The role carries no permission, so it has no age rule. They join through `/apply`, and the mods and the Team vote.
+
+### 🛡️ Moderators and the Chief of Mods
+
+- **Discord:** time out members, delete messages, manage threads and nicknames, read the audit log, quarantine
+  through Kira, and see the staff channels. **Moderators don't ban.** Bans are done by council members and the Chief of
+  Mods. Kira's automatic actions (the honeypot, clear scams, illegal images) stay as they are.
+- **Official server:** server operators (ops) are moderators in game. They need the 18+ rule and are confirmed the
+  same way (section 6, Server and SMP).
+- **Alone:** a timeout, a deleted message, a quarantine, with a reason in the mod case.
+- **The Chief of Mods** is the first contact for moderation questions. They organise the mods, can ban, and can take a
+  moderator's role away at once when there is a problem. The council confirms or reverses that within 72 hours.
+
+### 🧭 Group leads
+
+Section 6 says what a lead decides alone and what goes to the council.
+
+- **Discord:** in their group's channel only, delete messages, manage and pin threads, and ping the group role. The
+  🧭 lead role carries no server-wide permission.
+- **GitHub:** triage on the issues and pull requests that carry their group's label (`/label`, `/unlabel`, `/close`,
+  `/reopen`, `/unclaim`), from a list of group leads that grants no repository role. Leads merge only if they are on
+  the Horizon Team too.
+
+### 🌌 Horizon Team
+
+The Horizon Team **merges pull requests**. Its rules are in [the release flow](docs/release-flow.md): read the whole
+diff, never merge your own pull request, and use `needs-proof` for anything risky.
+
+- **GitHub:** member of the `horizon-team` team (write access to the Horizon repos), on the trusted reviewers list
+  (`/nightly` and triage commands).
+- **Discord:** the 🌌 Horizon Team role, #horizon-team, and writing in #contributors and the read-only channels.
+  Moderation permissions belong to the moderators and the council: a Team member moderates only if they also hold
+  one of those roles.
+- **During the 30-day probation:** they merge only ordinary pull requests. They don't merge `needs-proof` pull
+  requests, don't approve files that CODEOWNERS guards, and don't use `/nightly`.
+
+### 🏛️ Council
+
+- **Discord:** the 🏛️ Council role: the moderators' permissions plus ban and mention @everyone; #council (private);
+  starting polls in #polls-and-decisions.
+- **GitHub:** the `council` team. Over time it takes over the founder's CODEOWNERS review and his owner powers in the
+  release tools (section 11).
+- **Alone (any one member):** start a poll; pick up a member's request for a poll; do anything their other roles
+  allow.
+- **Any two members together:** an emergency action (section 4.6).
+- **Everything else** is decided by poll.
+
+## 4. The council and its polls
+
+### 4.1 Founding council
+
+kacpherek, levzzz5154, rdbtCVS, Online5277, dezer-x and Ludovic: six members, one vote each. The founding members
+don't go through the filter or a probation. They do make the 18+ declaration (section 9). The council has at most
+**9** members. It adds a seat only when a 2/3 poll says it needs one.
+
+### 4.2 How a poll works
+
+| Rule | Value |
+| --- | --- |
+| Who starts one | Any council member, with `/poll` (Kira). Anyone else asks a council member to start it |
+| Where | #polls-and-decisions, in public. Polls about a person (removal, appeals, the age rule) run in #council, and only their result is public |
+| How long | 24 hours. It closes early only if every council member has voted |
+| Ballot | Yes, No or Abstain. You can change it until the poll closes |
+| Quorum | At least half of the council votes (Abstain counts). With 6 members, 3 votes |
+| Simple majority | More Yes than No |
+| Two-thirds | Yes is at least 2/3 of the Yes and No votes, **and at least 3 Yes votes** |
+| Tie | Nothing changes |
+| No quorum | Nothing changes. Kira reminds the members who haven't voted 12 hours and 2 hours before the end |
+| About yourself | You don't vote, and you don't count in the council's size for that poll |
+| Asking again | A poll that failed can't be asked again for 7 days, unless two members agree that new facts justify it |
+
+### 4.3 Which threshold applies
+
+| Simple majority | Two-thirds |
+| --- | --- |
+| Day-to-day project decisions: direction, priorities, settling disputes between groups, a public statement | Adding council members and Horizon Team members |
+| Group leads and co-leads: appointing, removing, confirming every 6 months | Removing a council member or a Team member (without the person concerned) |
+| Moderators, the Chief of Mods, Support: confirming, removing | Rules: this document, the server rules, the contributing policy, the licence |
+| Ending a probation early | Money (section 12) |
+| Confirming an emergency action | Account handover steps (section 11) |
+| Second-level moderation appeals | Waiving part of the selection filter (section 5.4) |
+| Bringing back someone who stepped down for inactivity, within 6 months | Changing the council's size |
+
+**When in doubt, two-thirds.** Any council member can say a poll needs 2/3, and Kira then counts it at 2/3.
+
+### 4.4 Discussion
+
+Polls that add someone to the council, the Team or a lead post start with a **24-hour public discussion** (section
+5.3). Other polls are discussed in their own thread while they run. A member who wants more time votes No and says
+why. A failed poll can come back after 7 days.
+
+### 4.5 Conflicts of interest
+
+A member doesn't vote on a poll about themselves: their own role, their own removal, an appeal of their own
+moderation action, or money paid to them. They say so in the poll's thread and Kira leaves them out of the count.
+
+### 4.6 Emergencies
+
+For **security** (a leaked secret, a malicious pull request or mod, a hijacked account), **Mojang or Microsoft** (a
+request from them, a risk to the approved sign-in) or **legal** matters (a takedown, the law), **any two council
+members act at once**. They may:
+
+- pause releases and the Nightly;
+- take a mod down from the registry;
+- remove someone's roles or access for now;
+- lock or hide channels and content;
+- ask the account holder to rotate a secret or a key.
+
+They record it with `/emergency` in Kira, and both of them confirm it there. Kira opens a council poll at once
+(simple majority) to confirm it. If the poll doesn't pass, the action is undone where it can be. An emergency never
+adds members, changes rules or spends money.
+
+### 4.7 Removing a council member
+
+A 2/3 poll of the other members, in #council. The person concerned doesn't vote and doesn't count in the quorum.
+Only the result is published, never the reasons. Other ways to leave: resigning, inactivity (section 5.5), or a
+false age declaration (section 9).
+
+### 4.8 When the council drops below a quorum
+
+- **Fewer than 5 members:** Kira opens nominations for the council at once. The council fills seats within 30 days.
+- **Fewer than 3 members, or fewer than 3 who voted in the last 30 days:** an **interim council** forms. It counts the
+  remaining council members, the Horizon Team and the group leads past probation. Its only task is adding council
+  members, by its own 2/3 poll with a quorum of half. Any two of its members can take emergency actions. All other
+  decisions wait. The Team keeps merging and the leads keep leading.
+- **Nobody left:** the Team and the group leads form the interim council in the same way.
+
+## 5. The selection filter
+
+Nobody becomes a lead, a Team member or a council member just because they are well liked or talk a lot. Kira
+measures the work, and only people above a floor can be nominated. The council then decides among them.
+
+### 5.1 What Kira measures
+
+| Signal | What counts | Source |
+| --- | --- | --- |
+| **Merged pull requests** | Pull requests merged in a public horizon-rust repo. For Modding, also in the mod API's fork (arismoko/horizon). Counted overall, and per group by label or by files touched | GitHub search, as the ranks are counted today |
+| **Reviews** | Others' pull requests you reviewed: approved, asked for changes, or left a review with comments. One per pull request | GitHub search `reviewed-by:` and Kira's GitHub webhook |
+| **Triage** | Triage commands run (`/label`, `/close`, duplicates), issues labelled or closed, bug posts routed on Discord | The triage workflow's comments and Kira's webhook |
+| **Support answers** | #horizon-support posts you answered that ended solved | Kira's support feature |
+| **Active days** | Distinct days with any of the above, or with messages in #contributors or a group's channel. Chat elsewhere doesn't count | Kira |
+| **Tenure** | Days since your first counted contribution (since you joined the server, for moderators) | GitHub, Discord |
+| **Clean record** | No timeout, quarantine or ban in the last 90 days | Kira's mod cases |
+| **Verified GitHub** | `/verify-github` done | Kira |
+| **18+ declaration** | Made (section 9) | Kira |
+
+Kira turns these into an **evidence card**: the person's numbers, overall and in the group's area, for the last 60
+days and in total. Anyone can see their own card with `/evidence`. A nomination shows the card publicly.
+
+### 5.2 The floors
+
+A nomination is refused below these floors.
+
+| Role | Floor |
+| --- | --- |
+| **Group lead** | Verified GitHub; tenure of 30 days or more; **in the group's area: 8 or more merged pull requests, or 20 or more reviews** (Translations: 5 or more merged translation pull requests; Server and SMP: 8 pull requests, or 30 days as an official server operator with activity); 15 or more active days in the last 60; clean record; 18+ |
+| **Moderator** | In the server for 30 days or more; Kira level 10 or more; 15 or more active days in the last 60; clean record; 18+ |
+| **Chief of Mods** | Moderator for 30 days or more, past probation; 18+ |
+| **Horizon Team** | 🥇 Gold rank (40 merged pull requests); 20 or more reviews of others' pull requests; tenure of 30 days or more; 20 or more active days in the last 60; clean record; verified GitHub; 18+ |
+| **Council** | Horizon Team member, group lead or Chief of Mods for 60 days or more, past probation; 20 or more active days in the last 60; clean record; 18+ |
+
+The numbers are checked again once a year (section 15). They should stay reachable for people who really work on
+Horizon and out of reach for people who don't.
+
+### 5.3 The path to a role
+
+1. **Nomination.** Run `/nominate member: role: [group:]` in Kira.
+   - A **group lead** can be nominated by an active member of that group or by a council member. A self-nomination
+     needs a second from another active group member or a council member.
+   - A **Team member** can be nominated by a council or Team member. Someone can also nominate themselves with
+     `/apply`, if a council or Team member sponsors them.
+   - A **council member** can only be nominated by a council member.
+   - **Moderators** apply with `/apply`.
+2. **The filter.** Kira checks the floor and the 18+ declaration. Below the floor, Kira refuses and says which line
+   is short.
+3. **Public discussion, 24 hours.** Kira posts the nomination and the evidence card in a thread of
+   #polls-and-decisions. Contributors and the council can comment. For a lead, Kira also runs an **advisory poll** in
+   the group's channel for the same 24 hours. Only active group members vote in it, and the council sees the result.
+4. **Council poll, 24 hours.** Simple majority for a lead, 2/3 for the Team and the council. For moderators, the mods'
+   vote replaces this step, and any two council members can object within 24 hours; the council then decides by poll.
+5. **Probation, 30 days.** The role is held in full, except for the Team limits in section 3. At day 25, Kira asks the
+   council in #council whether anything is wrong. Probation ends by itself at day 30, unless a council poll (simple
+   majority) ended it earlier.
+
+### 5.4 Exceptions
+
+Some valuable people don't show up in the numbers, such as a designer for the website. The council can **waive the
+tenure or the area floors** by a 2/3 poll that says why. The age rule and the clean record are never waived.
+
+### 5.5 Inactivity
+
+Kira checks every day. It warns the person in a DM and in #council, then posts the step-down in
+#polls-and-decisions with neutral wording ("stepped down: inactive"), and removes the Discord role. The account
+holder or an org owner removes GitHub access when the Team role ends.
+
+| Role | What counts as activity | Warning | Steps down |
+| --- | --- | --- | --- |
+| Group lead | A counted action in the group's area, or messages in the group's channel | Day 21 | Day 30 |
+| Horizon Team | A merge or a review | Day 45 | Day 60 |
+| Moderator, Chief of Mods | A moderation action, or messages in the staff channels | Day 21 | Day 30 |
+| Support | An answer in #horizon-support | Day 21 | Day 30 |
+| Council | A vote in a poll. At 30 days with no vote, while at least 2 polls were held | Day 23 | Day 30, or 45 days with no counted activity at all |
+
+- **Away.** Anyone can announce an absence with `/away` for up to 45 days, once every 6 months. Away days don't
+  count. A lead names someone from the group to cover for them.
+- **Coming back.** Within 6 months: a simple-majority poll, with no new probation. After 6 months: the normal path.
+
+### 5.6 Terms
+
+- **Group leads** are confirmed every 6 months by a simple-majority poll. If someone else in the group passes the
+  floor and is nominated, both go on the same poll.
+- **Council and Team** have no fixed term. They stay as long as they are active and keep the council's trust. Removal
+  is always possible (section 4.7).
+
+## 6. Theme groups
+
+### 6.1 The groups
+
+| Group | Covers | GitHub | Discord |
+| --- | --- | --- | --- |
+| **Modding** | The mod API, native and content mods, mixins, the mod registry, `cargo horizon-mod` | The mod API lives in Ari's fork **arismoko/horizon**. Its owner runs that repo by their own rules; the council governs only what is Horizon's: horizon-rust/horizon-mods, horizon-mixins, horizon-native-mod-template, the registry. Label `mods` | The 🧩 MODDING category (#modding, #horizon-modding-team); roles 🧩 Modder (picked) and 🧩 Horizon Modding Team (the lead gives it) |
+| **Shaders and rendering** | The renderer, shaders, shader packs, OptiFine and Polytone pack formats | Label `rendering`; `crates/horizon-client-render` (gfx), `*.wgsl`, `horizon-shaders`, `horizon-shader-api`, `horizon-optifine`, `horizon-polytone` | #shaders-rendering |
+| **Performance** | Frame rate, memory, server tick, benchmarks | Label `perf`; `horizon-bench`, the benchmark tools | #performance |
+| **Launcher** | The launcher: installs, updates, instances, its pages | Label `launcher`; `launcher/` | #launcher |
+| **Server and SMP** | Dedicated server, hosting, the anticheat, multiplayer, and the official SMP | Labels `server`, `multiplayer`; `horizon-server*`, `horizon-anticheat`, `lan/`, `dedicated*`; horizon-rust/horizon-server | #server-smp (plus #join-server, #server-chat) |
+| **Translations** | The game's and the launcher's languages | Label `roadmap:languages`; `launcher/lang/`, `crates/horizon-client/assets/horizon/lang/` | #translations and the 🌍 language channels |
+| **Website** | playhorizon.dev | horizon-rust/horizon-site; label `website`. The site's design stays as it is unless the council decides otherwise | #website |
+| **Vanilla accuracy** | Parity with vanilla 26.3: harnesses, oracles, the port ledger | Labels `parity`, `parity-regression`, `full-parity`; `tools/test_*_parity.py`, the Java oracles | #vanilla-accuracy |
+| **UI** | The game's menus, HUD, settings, controller navigation, the design system | Labels `ui`, `accessibility`; `title/`, `settings_shell.rs`, `hud*`, `ui.rs`, `docs/design-system.md`, `horizon-theme`. The launcher's look is shared with Launcher | #ui |
+
+A pull request can belong to two groups. Both leads can comment, and the Team merges as usual. If the leads disagree,
+the council decides.
+
+### 6.2 Leads per group
+
+- **One lead per group.** A group with 8 or more active members may also have **one co-lead**, chosen the same way.
+- A person leads **at most two groups**. Council members may lead a group, though a lead from outside the council is
+  preferred: it spreads the work.
+
+### 6.3 What a lead decides alone
+
+Inside their group's topic, and within this document, the contributing guide, the vanilla-first rule, the layers and
+the design system:
+
+- the group's priorities and the order of its roadmap items;
+- which issues are `good first issue`, and triage of the group's issues;
+- technical and design direction inside the area, when vanilla behaviour and the default look don't change;
+- accepting or declining an idea or a proposal in the area. Any two active group members or one council member can
+  take that decision to the council;
+- how the group organises itself (threads, meetings, the channel's rules on top of the server's);
+- asking the Team for reviews, adding `needs-proof`, and nominating people.
+
+### 6.4 What goes to the council
+
+- the rules, money, accounts and secrets;
+- who is on the council, the Team or the mods;
+- anything that changes vanilla behaviour or turns a Horizon-only feature on by default;
+- breaking a public promise: the mod API, server compatibility, save and file formats;
+- disputes between groups;
+- anything involving Mojang, Microsoft or the law;
+- speaking for the whole project outside the group's topic.
+
+### 6.5 A group without a lead
+
+The work goes on. The Team reviews and merges, and Kira still routes the group's issues and questions to its
+channel. Until a lead is chosen, any council member may take a lead's decision for that group and says so in the
+channel. Kira pins a "lead wanted" note with the floor. **No lead is better than a lead who doesn't do the work:**
+nobody is appointed just to fill the seat.
+
+## 7. Moderation and appeals
+
+- **The server rules** are in #rules. Moderators enforce them, the Chief of Mods leads the mods, and the council can
+  change the rules (2/3).
+- **Every action has a mod case**: who acted, what they did, and why. Kira keeps the cases.
+- **First appeal:** within 14 days, through #appeal (for a quarantine) or mod mail. A moderator who wasn't involved,
+  or the Chief of Mods, answers within 72 hours.
+- **Second appeal:** for bans, timeouts over 24 hours and quarantines, a council poll in #council (simple majority).
+  Members who were involved don't vote. The answer is final for 90 days.
+- **Not appealable here:** actions that Discord's rules or the law require. Those are reported where the law says.
+- **Removing a moderator:** the Chief of Mods can suspend a moderator at once, and the council decides within 72 hours
+  (simple majority). The council removes the Chief of Mods the same way.
+- **Staff are moderated like everyone.** When a council member is involved, the council decides without them.
+
+## 8. Conflicts and hard cases
+
+| Case | What happens |
+| --- | --- |
+| Two groups disagree | The leads talk first. If they still disagree, the council decides (simple majority) |
+| A lead's decision is contested | Any two active group members or one council member can bring it to the council |
+| A Team member merges against the rules | Any council member can revert the merge. The council can remove the member (2/3) |
+| A council member breaks the rules | The council decides without them. Removal takes 2/3 (section 4.7) |
+| Someone holds a role and is under 18 | Section 9 |
+| The council can't reach quorum | Section 4.8 |
+| The founder and the council disagree about one of his own accounts | Until a step of section 11 hands it over, the account stays his. He carries out the council's decisions on project matters, or he says publicly that he won't |
+
+## 9. The age rule (18+)
+
+**Who must be 18 or older:** members of the council and the Horizon Team, trusted reviewers, group leads and
+co-leads, the Chief of Mods and the moderators, official server operators, and anyone with admin rights anywhere in
+the project: Discord (Administrator, Manage Roles, Manage Channels, ban), GitHub (write, admin, organisation),
+server panels, Railway, or Kira's admin side. The same goes for anyone who holds a project secret.
+
+**Who doesn't have to be:** members, contributors (with any rank), group members and 🤝 Support. Contributors under
+18 are welcome and valued. They just can't hold the roles above.
+
+**How it's checked, without collecting ID:**
+
+- **A declaration.** Before taking such a role, and once at the start for everyone who holds one, the person presses
+  a button in Kira: "I confirm that I am 18 or older. I understand that a false declaration removes all my roles of
+  trust." Kira keeps only the Discord account, the date and the wording's version. It never stores a birth date, an
+  ID, a photo, or any outside age-checking service's result.
+- **No declaration, no role.** At the start, current role holders have 7 days to make it. Until they do, their role is
+  paused.
+- **When there's doubt** (the person says they are younger, or there is a credible private report), one council
+  member asks the person privately. If the doubt remains, any council member pauses the role, and the council decides
+  within 72 hours in #council.
+- **A false declaration** removes every role of trust at once, and the person can't hold one for 12 months.
+- **Privacy.** Age is never discussed in public. A role that ends for this reason ends with the same neutral line as
+  any other step-down.
+
+## 10. The agents
+
+Horizon uses AI agents: the founder's orchestrator, which runs coding agents, and Kira, the Discord bot.
+
+- **They obey council decisions only:** a passed poll recorded by Kira, a recorded emergency action of two council
+  members, and the standing rules in this document and the project's docs.
+- **The only exception is the founder's own things:** his spending, his machines (they run CI and the vanilla tests),
+  his personal accounts and his time. On those, his word decides. This list should get shorter over time (section 11).
+- **Role work isn't a decision.** A lead asking Kira to route issues, or a Team member asking an agent to prove a pull
+  request, is that person using their role. The agents help, within the role's powers.
+- **They check the source.** An agent acts on a decision only when it finds it in Kira's decisions log
+  (section 13). A message saying "the council decided", or a screenshot, is not enough.
+- **They post as agents.** Everything an agent posts says it comes from an agent, and states decisions as the
+  project's.
+
+## 11. Accounts and the handover path
+
+Today the founder holds every account. The aim is for him to hold fewer, in an order that never leaves the project
+unable to act, and never puts an account that is tied to a person into anyone else's hands.
+
+| Account | Today | Can it be shared? | Plan |
+| --- | --- | --- | --- |
+| **GitHub organisation** (horizon-rust) | One owner (the founder) | Yes: an organisation can have several owners | **Step 1:** a second owner from the council, chosen by a 2/3 poll in the council's first week, with two-factor authentication on. **Step 2:** a `council` team; CODEOWNERS reviews and the release tools' owner powers (`paused`, `/nightly remove`) move from the founder to that team |
+| **Discord server** | Owned by the founder | Partly: a server has exactly one owner; powers can be given through roles | **Step 1:** the 🏛️ Council role gets moderation and ban permissions; Kira applies the outcomes of passed polls, so nobody needs Manage Roles; two-factor authentication becomes required for moderation. Ownership itself stays with the founder until a legal entity exists |
+| **Kira** (bot application, Railway service) | The founder's Discord developer account and Railway | The bot: yes (a Discord developer team). Railway: adding members may need a paid plan | **Step 1:** a Discord developer team with two council members. Railway members once the council decides on money |
+| **Official server** (hosting panel) | The founder's account | Yes: panel sub-users | **Step 1:** sub-users for the Server and SMP lead and for one council member |
+| **Domains** (playhorizon.dev and the others) | The founder's registrar account | Not without moving it | Auto-renewal on, registered for several years ahead. They move only to a legal entity, if one is created |
+| **The Microsoft app approved by Mojang** (sign-in) | The founder's Azure app registration; Mojang approved it after his application | **No.** The approval was given on his application. Moving the app or adding owners would change who Mojang deals with, and we have found no documented way to transfer an approval | **Never moves** without Mojang's written agreement. The only change considered: a legal entity, if one is created, and only if Mojang agrees |
+| **Signing** (Apple developer certificate, release signing keys) | The founder's | The Apple certificate is in his legal name: no | The Apple certificate never moves. Release keys stay in GitHub's protected environments, and the council team approves their use from step 2 |
+| **Money** (sponsorship, donations) | Personal accounts of the founder | Through a fiscal host | Section 12 |
+| **The founder's machines, AI accounts and password vault** | His | No | His own things: they never move. The project should depend on them less over time |
+
+**Order:** first the safety nets that remove a single point of failure (a second organisation owner, the bot's
+developer team, panel sub-users). Then the day-to-day powers (CODEOWNERS and release tools to the council team). Last,
+whatever needs a legal entity: domains, money, and with Mojang's agreement the sign-in app. Each step is a 2/3 poll,
+and the founder carries it out.
+
+## 12. Money
+
+*Placeholder: the options (Open Collective and others) are being researched.*
+
+- The council approves every expense by a **2/3 poll**.
+- **Every income and every expense is public.**
+- Nobody votes on money paid to themselves.
+
+## 13. Transparency
+
+- **#polls-and-decisions:** every poll and every result, posted by Kira, and the 24-hour discussions of nominations.
+  For polls that aren't about a person, each member's vote is shown once the poll closes.
+- **The decisions log:** Kira keeps an append-only record of every poll, emergency action, appointment and
+  step-down, with its date and result. It is public and machine-readable, so the agents can check a decision there.
+- **This document** lives in horizon-rust/horizon as `GOVERNANCE.md`. A short summary is pinned in #rules and in
+  #polls-and-decisions.
+- **Who holds which role:** the people page of playhorizon.dev's hub shows the council, the Team, the group leads,
+  the Chief of Mods, the moderators and Support.
+- **#council** is private for discussion and for polls about people. Everything the council decides is published.
+
+## 14. Rules that are never voted on
+
+These are Horizon's conditions for existing, not choices. No poll can change them:
+
+- Playing needs a **Microsoft account that owns Minecraft: Java Edition**. There is no play without one.
+- **No Mojang files** in Horizon's repos or downloads. Players' own copies stay on their own machines.
+- **No gambling**, in any form, including with in-game currency.
+- **Mojang's and Microsoft's terms and Usage Guidelines** apply to everything Horizon does.
+- **The law**, and the terms of service of Discord and GitHub.
+
+## 15. Changing this document
+
+A 2/3 council poll, then a pull request that a Team member merges. The council reviews the floors' numbers
+(section 5.2) once a year, or sooner if they turn out wrong.

README.md

@@ -135,6 +135,8 @@ python3 tools/pr_ready.py
 
 It runs rustfmt, clippy, the touched crates' tests, the Python tests, the public-tree check and the vanilla harnesses your change affects. Never commit game files, decompiled source or prepared resources.
 
+How Horizon is run (the council, theme groups and their leads, the Horizon Team, moderation): [GOVERNANCE.md](GOVERNANCE.md).
+
 ## Project status
 
 **Player-visible gaps: 0 open** of the 833 the [port ledger](tools/port_ledger.py) found, reading every vanilla 26.3 method against Horizon's code: vanilla behaviour a player would notice that Horizon doesn't have yet. By area: Animals [0](https://github.com/horizon-rust/horizon/issues/3512); Monsters and bosses [0](https://github.com/horizon-rust/horizon/issues/3513); Entities, projectiles, vehicles and decorations [0](https://github.com/horizon-rust/horizon/issues/3514); Items, enchantments and inventories [0](https://github.com/horizon-rust/horizon/issues/3515); Blocks, redstone and fluids [0](https://github.com/horizon-rust/horizon/issues/3516); World, world generation and saves [0](https://github.com/horizon-rust/horizon/issues/3517); Screens, HUD and client packets [0](https://github.com/horizon-rust/horizon/issues/3518); Entity and block rendering, models [0](https://github.com/horizon-rust/horizon/issues/3519); Server and players on the server [0](https://github.com/horizon-rust/horizon/issues/3520); Mob AI, villagers and raids [0](https://github.com/horizon-rust/horizon/issues/3521). This number goes down as gaps close (`tools/parity_gaps.py`); the table below says what the harnesses compare.

crates/horizon-addresses/src/lib.rs

@@ -15,6 +15,10 @@ pub const OFFICIAL_SERVER: &str = "play.playhorizon.dev";
 /// `official_server_previous` in `launcher/links.json`).
 pub const OFFICIAL_SERVER_PREVIOUS: &[&str] = &["horizon.bunchy7s.dev"];
 
+/// Afri-Network, a partner server the game added once below the official server (#9299) until
+/// the partnership ended: kept so the game can take back out the entry it added.
+pub const WITHDRAWN_PARTNER_SERVER: &str = "afri-network.co.za";
+
 /// [`OFFICIAL_SERVER`] with the port its SRV record gives, for askers that don't look SRV up
 /// (the telemetry server's status checks).
 pub const OFFICIAL_SERVER_STATUS: &str = "play.playhorizon.dev:24454";

crates/horizon-client-input/Cargo.toml

@@ -9,11 +9,13 @@ description = "The client's input layer: key bindings and their names, mouse, co
 [dependencies]
 horizon-client-core = { path = "../horizon-client-core" }
 winit = "0.30.13"
-# The window icon.
-horizon-theme = { path = "../horizon-theme" }
 png = "0.18"
 arboard = { version = "3.6.1", default-features = false, features = ["wayland-data-control"] }
 
+[dev-dependencies]
+# The window icon test decodes Horizon's icon.
+horizon-theme = { path = "../horizon-theme" }
+
 [features]
 controllers = []
 

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

@@ -1441,6 +1441,16 @@ pub enum Rumble {
     },
     Totem,
 }
+impl From<crate::input_source::Feedback> for Rumble {
+    fn from(event: crate::input_source::Feedback) -> Self {
+        use crate::input_source::Feedback;
+        match event {
+            Feedback::BlockBroken => Rumble::BlockBroken,
+            Feedback::Explosion { distance, radius } => Rumble::Explosion { distance, radius },
+            Feedback::Totem => Rumble::Totem,
+        }
+    }
+}
 /// A vibration: the heavy (low-frequency) and light motors, 0..1, and how
 /// long it lasts.
 #[derive(Clone, Copy, Debug, PartialEq)]

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

@@ -0,0 +1,15 @@
+//! The engine's side of the input source (docs/layers.md, "Controllers, splitscreen, replays and
+//! UI pages"): what gameplay tells a device beyond the keyboard and mouse. Gameplay names these
+//! types, never a controller's; the controller code answers.
+
+/// Something that happened to the player that a device may let them feel (a controller's
+/// vibration). The device decides how, or whether.
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum Feedback {
+    /// The player broke a block.
+    BlockBroken,
+    /// An explosion this far away (blocks) with this power.
+    Explosion { distance: f64, radius: f32 },
+    /// A totem of undying saved the player.
+    Totem,
+}

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

@@ -9,6 +9,7 @@ pub mod gamepad;
 pub mod gameplay_guide;
 pub mod held;
 pub mod input;
+pub mod input_source;
 pub mod interaction_input;
 pub mod key_names;
 pub mod keybinds;

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

@@ -638,10 +638,30 @@ pub fn fullscreen_request(
     }
 }
 
-/// Horizon's icon for the window's title bar and the task bar (X11 and Windows; Wayland takes
-/// it from the `horizon.desktop` entry, macOS from the app bundle). `None` if it can't be read.
+/// The PNG the windows show as their icon, given once at startup by the layer that brands the
+/// game (the engine has none of its own).
+static ICON_PNG: std::sync::OnceLock<&'static [u8]> = std::sync::OnceLock::new();
+
+/// Give the windows their icon, a PNG: call it before the first window opens. A second call
+/// keeps the first icon.
+pub fn set_icon_png(png: &'static [u8]) {
+    let _ = ICON_PNG.set(png);
+}
+
+/// The icon given to [`set_icon_png`], if any.
+pub fn icon_png() -> Option<&'static [u8]> {
+    ICON_PNG.get().copied()
+}
+
+/// The icon for the window's title bar and the task bar (X11 and Windows; Wayland takes it from
+/// the `.desktop` entry, macOS from the app bundle). `None` with no icon given, or one that
+/// can't be read.
 pub fn icon() -> Option<winit::window::Icon> {
-    let mut decoder = png::Decoder::new(std::io::Cursor::new(horizon_theme::ICON_PNG));
+    decode_icon(icon_png()?)
+}
+
+fn decode_icon(png: &[u8]) -> Option<winit::window::Icon> {
+    let mut decoder = png::Decoder::new(std::io::Cursor::new(png));
     decoder.ignore_checksums(true);
     decoder.set_transformations(png::Transformations::EXPAND | png::Transformations::STRIP_16);
     let mut reader = decoder.read_info().ok()?;
@@ -654,14 +674,15 @@ pub fn icon() -> Option<winit::window::Icon> {
     winit::window::Icon::from_rgba(bytes, info.width, info.height).ok()
 }
 
-/// Apply Horizon's icon to every window. Windows has a separate taskbar icon slot from the small
-/// window icon; requiring the decoded icon there prevents a generic taskbar icon from appearing.
-pub fn with_horizon_icon(
-    attributes: winit::window::WindowAttributes,
-) -> winit::window::WindowAttributes {
+/// Apply the icon given to [`set_icon_png`] to a window. Windows has a separate taskbar icon slot
+/// from the small window icon; requiring a given icon to decode there prevents a generic taskbar
+/// icon from appearing.
+pub fn with_icon(attributes: winit::window::WindowAttributes) -> winit::window::WindowAttributes {
+    #[cfg(not(target_os = "windows"))]
     let icon = icon();
     #[cfg(target_os = "windows")]
-    let icon = Some(icon.expect("Horizon's icon must be available on Windows"));
+    let icon =
+        icon_png().map(|png| decode_icon(png).expect("the window icon must decode on Windows"));
 
     let attributes = attributes.with_window_icon(icon.clone());
     #[cfg(target_os = "windows")]
@@ -739,7 +760,8 @@ mod tests {
     }
     #[test]
     fn the_window_icon_decodes() {
-        assert!(icon().is_some());
+        assert!(decode_icon(horizon_theme::ICON_PNG).is_some());
+        assert!(decode_icon(b"not a png").is_none());
     }
 
     #[test]

crates/horizon-client-lib/Cargo.toml

@@ -70,7 +70,6 @@ flate2 = { version = "1.1.10", default-features = false, features = ["zlib-rs",
 mio = { version = "1.2.4", features = ["os-poll", "net"] }
 # Shared chunk frames are found by one keyed 128-bit hash of their body (lan/conn.rs SharedFrames).
 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).
 horizon-telemetry = { path = "../horizon-telemetry", default-features = false }
 horizon-bench = { path = "../horizon-bench" }
@@ -109,17 +108,12 @@ objc2-foundation = { version = "0.3", default-features = false, features = ["std
 wgpu = { version = "30.0.1", default-features = false, features = ["gles"] }
 
 [features]
-default = ["audio", "controllers", "horizon-extras"]
+default = ["audio", "controllers"]
 # 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", "horizon-client-input/controllers"]
-# Horizon's own parts (docs/forking.md, docs/layers.md): the features below, and the official
-# server in the list (`official_servers`).
-horizon-extras = ["discord"]
-# "Playing Horizon" on the player's Discord profile (`discord_presence`).
-discord = []
 # 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.
@@ -131,6 +125,8 @@ windows-segment-heap = []
 workspace = true
 
 [dev-dependencies]
+# ui_theme's unit tests draw text in the design system's fonts.
+horizon-theme = { path = "../horizon-theme" }
 horizon-client-render = { path = "../horizon-client-render", features = ["test-support"] }
 horizon-items = { path = "../horizon-items", features = ["test-support"] }
 # Every WGSL shader translated as wgpu's DirectX 12 backend does (gfx.rs tests).

crates/horizon-client-render/Cargo.toml

@@ -24,12 +24,12 @@ horizon-narrator = { path = "../horizon-narrator" }
 # OptiFine-format pack files: random entity textures (hud.rs), connected textures
 # (connected.rs) and custom item texture rules (cit.rs).
 horizon-optifine = { path = "../horizon-optifine" }
+horizon-pack-options = { path = "../horizon-pack-options" }
 horizon-polytone = { path = "../horizon-polytone" }
 horizon-protocol = { path = "../horizon-protocol" }
 horizon-shader-api = { path = "../horizon-shader-api" }
 horizon-shaders = { path = "../horizon-shaders" }
 horizon-system = { path = "../horizon-system" }
-horizon-theme = { path = "../horizon-theme" }
 horizon-threads = { path = "../horizon-threads" }
 horizon-world = { path = "../horizon-world" }
 ab_glyph = "0.2.32"
@@ -76,10 +76,16 @@ wgpu = { version = "30.0.1", default-features = false, features = ["gles"] }
 audio = ["dep:cpal"]
 # Helpers horizon-client's tests build their fixtures with.
 test-support = []
+# horizon-client's `horizon-extras`: asking the device for hardware ray tracing on request
+# (`gfx/ray_query.rs`, `HORIZON_RAY_TRACING=1`). Without it the device is requested as without
+# the variable.
+horizon-extras = []
 
 [lints]
 workspace = true
 
 [dev-dependencies]
+# Tests: a TrueType font to load, and the design system the menus' motion curves match.
+horizon-theme = { path = "../horizon-theme" }
 horizon-items = { path = "../horizon-items", features = ["test-support"] }
 naga = { version = "30.0.1", features = ["wgsl-in", "hlsl-out", "glsl-out", "msl-out", "spv-out"] }

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

@@ -0,0 +1,158 @@
+//! Audio occlusion, attenuation and mixing benchmark.
+//! Run with: `cargo run --profile fast -p horizon-client-render --example audio_bench`
+use horizon_client_render::{
+    audio::Audio,
+    sound_engine::{MobSound, SoundInstance, Sounds, TickContext},
+};
+use std::{path::Path, time::Instant};
+
+fn main() {
+    println!("=== Horizon Audio Attenuation & Mixing Benchmark ===");
+
+    let mut audio = Audio::silent(Path::new("/nonexistent"));
+    audio.engine.loaded = true;
+    audio.backend_live_for_bench();
+    audio.record_heard = false;
+
+    // Register a sound event with attenuation distance 16
+    audio.engine.registry.add_file(
+        "minecraft",
+        br#"{"bench.loop":{"attenuation_distance":16,"sounds":[{"name":"bench/loop","stream":false}]}}"#,
+        &|_, _| true,
+    );
+    // Insert 1 second of audio into cache (48000 mono samples)
+    let samples: Vec<f32> = (0..48_000)
+        .map(|i| ((i as f32) * 440.0 * 2.0 * std::f32::consts::PI / 48000.0).sin() * 0.5)
+        .collect();
+    audio.insert_cached_sound("minecraft:bench/loop", samples, 48_000, 1);
+
+    // 1. Benchmark set_listener (called every client render frame)
+    let listener_iterations = 200_000;
+    let start = Instant::now();
+    for i in 0..listener_iterations {
+        let angle = (i as f32) * 0.01;
+        audio.set_listener(
+            [
+                100.0 + (angle.cos() as f64) * 5.0,
+                64.0,
+                200.0 + (angle.sin() as f64) * 5.0,
+            ],
+            angle,
+            0.0,
+        );
+    }
+    let listener_elapsed = start.elapsed();
+    println!(
+        "1. set_listener moving (render frame): {:?} for {} calls ({:.2} ns/call)",
+        listener_elapsed,
+        listener_iterations,
+        (listener_elapsed.as_nanos() as f64) / (listener_iterations as f64)
+    );
+
+    // 1b. Benchmark set_listener stationary (lock elimination early-out)
+    let stationary_iterations = 200_000;
+    let start = Instant::now();
+    for _ in 0..stationary_iterations {
+        audio.set_listener([100.0, 64.0, 200.0], 0.0, 0.0);
+    }
+    let stationary_elapsed = start.elapsed();
+    println!(
+        "1b. set_listener stationary (lock early-out): {:?} for {} calls ({:.2} ns/call)",
+        stationary_elapsed,
+        stationary_iterations,
+        (stationary_elapsed.as_nanos() as f64) / (stationary_iterations as f64)
+    );
+
+    // 2. Play 128 sounds in the world at various distances from listener at [100.0, 64.0, 200.0]
+    // 64 sounds within attenuation distance (<16 blocks)
+    // 64 sounds outside attenuation distance (>16 blocks)
+    for i in 0..128 {
+        let dist = if i < 64 {
+            (i as f64) * 0.24 // 0 to 15.1 blocks (audible)
+        } else {
+            17.0 + ((i - 64) as f64) * 1.5 // 17 to 111.5 blocks (out of attenuation range)
+        };
+        let pos = [100.0 + dist, 64.0, 200.0];
+        let instance = SoundInstance::new(
+            "minecraft:bench.loop",
+            crate_sound_source(i),
+            1.0,
+            1.0,
+            horizon_core::random::LegacyRandom::new(i as i64),
+            true, // looping
+            0,
+            horizon_client_render::sound_engine::Attenuation::Linear,
+            pos,
+            false,
+        );
+        audio.play_instance(instance, false);
+    }
+
+    // 3. Benchmark mix_buffer (5000 buffers of 1024 stereo frames @ 48kHz = ~106 seconds of audio mixing)
+    let mut buffer = vec![0.0f32; 1024 * 2];
+    let mix_iterations = 5_000;
+    let start = Instant::now();
+    for _ in 0..mix_iterations {
+        audio.mix_buffer(&mut buffer, 2, 48_000);
+    }
+    let mix_elapsed = start.elapsed();
+    println!(
+        "2. mix_buffer (128 active channels, 1024 stereo frames): {:?} for {} buffers ({:.2} µs/buffer)",
+        mix_elapsed,
+        mix_iterations,
+        (mix_elapsed.as_micros() as f64) / (mix_iterations as f64)
+    );
+
+    // 4. Benchmark SoundEngine::tick with ticking mob sounds
+    let mut mobs = Vec::new();
+    for i in 0..64 {
+        mobs.push(MobSound {
+            id: 2000 + i,
+            position: [100.0 + (i as f64) * 0.5, 64.0, 200.0 + (i as f64) * 0.5],
+            speed: 0.25,
+            baby: false,
+            angry: i % 2 == 0,
+            silent: false,
+            attack_scale: 0.5,
+            sniffer_digging: false,
+        });
+    }
+
+    let tick_ctx = TickContext {
+        player_underwater: false,
+        player_removed: false,
+        vehicle: None,
+        carts: Vec::new(),
+        mobs: mobs.clone(),
+        frozen: false,
+        player_position: [100.0, 64.0, 200.0],
+        player_speed_sqr: 0.1,
+        player_fall_flying: false,
+        ridden: None,
+        camera_position: [100.0, 64.0, 200.0],
+    };
+
+    let tick_iterations = 10_000;
+    let start = Instant::now();
+    for _ in 0..tick_iterations {
+        audio.tick(false, &tick_ctx);
+    }
+    let tick_elapsed = start.elapsed();
+    println!(
+        "3. SoundEngine::tick (64 channels + ticking): {:?} for {} ticks ({:.2} µs/tick)",
+        tick_elapsed,
+        tick_iterations,
+        (tick_elapsed.as_micros() as f64) / (tick_iterations as f64)
+    );
+}
+
+fn crate_sound_source(i: u32) -> usize {
+    match i % 6 {
+        0 => 0, // master
+        1 => 1, // music
+        2 => 2, // records
+        3 => 3, // weather
+        4 => 4, // blocks
+        _ => 5, // hostile
+    }
+}

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

@@ -288,6 +288,8 @@ fn zip_pack(id: &str, path: PathBuf) -> Pack {
 }
 
 fn main() {
+    // The pack formats the game installs at startup, so their loading is measured too.
+    horizon_client_render::pack_formats::install();
     let args: Vec<String> = std::env::args().collect();
     let scale = args
         .iter()

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

@@ -386,6 +386,7 @@ fn replay(window: Arc<Window>) -> Result<(), Box<dyn std::error::Error>> {
                 path: path.clone(),
                 size: None,
                 scaled: false,
+                background: false,
             });
             for _ in 0..32 {
                 draw(&mut renderer)?;

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

@@ -207,6 +207,7 @@ fn fixture(window: Arc<Window>) -> Result<(), Box<dyn std::error::Error>> {
         path: out.join("cpu.png"),
         size: None,
         scaled: false,
+        background: false,
     });
     renderer.render(&frame)?;
     let expected = read(&out.join("cpu.png"));
@@ -251,6 +252,7 @@ fn fixture(window: Arc<Window>) -> Result<(), Box<dyn std::error::Error>> {
         path: out.join("gpu.png"),
         size: None,
         scaled: false,
+        background: false,
     });
     renderer.render(&frame)?;
     assert_eq!(

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

@@ -167,6 +167,7 @@ fn fixture(window: Arc<Window>) -> Result<(), Box<dyn std::error::Error>> {
             path: path.clone(),
             size: None,
             scaled: false,
+            background: false,
         });
         // twice: the first frame of a new warp builds it
         renderer.render(&frame).unwrap();
@@ -336,6 +337,7 @@ fn bench(renderer: &mut Renderer, out: &Path) -> Result<(), Box<dyn std::error::
             path: out.join("bench.png"),
             size: None,
             scaled: false,
+            background: false,
         });
         renderer.render(&frame).unwrap();
         renderer.render(&frame).unwrap();

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

@@ -99,10 +99,8 @@ pub struct RenderAssets {
     pub pbr_normals: Vec<u8>,
     pub pbr_specular: Vec<u8>,
     pub pbr_size: u32,
-    /// OptiFine connected textures (empty without `optifine/ctm` files).
-    pub connected: crate::connected::ConnectedTextures,
-    /// Fusion connected textures (empty without Fusion's connecting textures and models).
-    pub fusion: crate::fusion::FusionTextures,
+    /// The packs' connected textures (OptiFine's, Fusion's), when they have some.
+    pub connected: Option<crate::connected::Connected>,
     /// Counts up each time resources load, from 1: a native mod asks again where blocks'
     /// sprites are when it changes (`native_block_sprites_version`).
     pub generation: u64,
@@ -345,45 +343,32 @@ impl RenderAssets {
             sprites.insert(root, &format!("minecraft:block/destroy_stage_{stage}"))?;
             sprites.insert(root, &format!("minecraft:block/destroy_oit_stage_{stage}"))?;
         }
-        let fusion = if draws {
-            let _step = crate::spans::startup::step("core.fusion");
-            crate::fusion::FusionTextures::load(root, registry, &mut sprites, &mut models.catalog)
-        } else {
-            Default::default()
-        };
         let mut emissive = Vec::new();
         let connected = if draws {
-            crate::native_emissive::load(root, &mut sprites);
-            // A side's sprite, for rules that connect by tile: the first quad facing it.
-            let catalog = &models.catalog;
-            let mut found = Vec::new();
-            crate::connected::ConnectedTextures::load(
+            // Native mods' emissive textures go where the pack format puts them (after its
+            // models' tiles, before its rules' tiles), else after both.
+            let mut native_loaded = false;
+            let mut native = |sprites: &mut crate::sprites::Sprites| {
+                if !std::mem::replace(&mut native_loaded, true) {
+                    crate::native_emissive::load(root, sprites);
+                }
+            };
+            let connected = crate::pack_hooks::formats().connected_textures(
                 root,
                 registry,
                 &mut sprites,
-                |state, face| {
-                    let side = horizon_assets::model::Direction::ALL[face as usize];
-                    catalog
-                        .models_at(
-                            state,
-                            horizon_core::position::BlockPos::new(0, 0, 0),
-                            &mut found,
-                        )
-                        .ok()?;
-                    found
-                        .iter()
-                        .flat_map(|m| &m.faces)
-                        .find(|f| f.quad.facing == side)
-                        .map(|f| f.layer)
-                },
-            )
+                &mut models.catalog,
+                &mut native,
+            );
+            native(&mut sprites);
+            connected
         } else {
-            Default::default()
+            None
         };
         // After the connected tiles: a tile identical to a block shares its layer, and the
         // overlays skip shared layers.
-        if draws {
-            emissive = crate::native_emissive::load_optifine(root, &mut sprites);
+        if draws && let Some(suffix) = crate::pack_hooks::formats().emissive_suffix(root) {
+            emissive = crate::native_emissive::load_overlays(root, &suffix, &mut sprites);
         }
         sprites.save_disk_cache();
         if draws {
@@ -411,7 +396,6 @@ impl RenderAssets {
             pbr_specular: sprites.specular,
             pbr_size: sprites.pbr_size,
             connected,
-            fusion,
             generation: GENERATION.fetch_add(1, std::sync::atomic::Ordering::Relaxed) + 1,
         })
     }

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

@@ -233,11 +233,11 @@ pub fn texture_path(root: &Path, texture: &str, directory: &str) -> PathBuf {
     }
     let (namespace, path) = texture.split_once(':').unwrap_or(("minecraft", texture));
     let rel = format!("assets/{namespace}/{directory}/{path}.png");
-    root.join(if horizon_optifine::paths::valid(&rel) {
-        &rel
-    } else {
-        NOWHERE
-    })
+    // No `.`, `..` or empty segment, and no `\` (a separator on Windows, where `..\..` climbs).
+    let stays = rel
+        .split('/')
+        .all(|segment| !matches!(segment, "" | "." | "..") && !segment.contains('\\'));
+    root.join(if stays { &rel } else { NOWHERE })
 }
 
 /// `SpriteSourceList.list`: every sprite id of the atlas and its origin.

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

@@ -478,6 +478,7 @@ pub struct Audio {
     pub record_heard: bool,
     pub listener: [f64; 3],
     pub listener_yaw: f32,
+    pub listener_pitch: f32,
     pub master: f32,
     /// Seeds of positional plays (the client level random's `nextLong`).
     random: LegacyRandom,
@@ -722,6 +723,29 @@ impl Backend for MixerBackend {
     fn set_unmuffled(&mut self, channel: ChannelId, unmuffled: bool) {
         self.with(channel, |c| c.unmuffled = unmuffled);
     }
+    fn update_channel(&mut self, channel: ChannelId, volume: f32, pitch: f32, position: [f64; 3]) {
+        if let Ok(mut m) = self.mixer.lock()
+            && let Some(c) = m.channels.get_mut(&channel)
+        {
+            c.gain = volume;
+            c.pitch = pitch;
+            c.at = [position[0] as f32, position[1] as f32, position[2] as f32];
+        }
+    }
+    fn filter_stopped(&mut self, live: &[(u64, ChannelId)], stopped: &mut Vec<u64>) {
+        if let Ok(m) = self.mixer.lock() {
+            for &(h, c) in live {
+                if m.channels
+                    .get(&c)
+                    .is_none_or(|ch| ch.state == State::Stopped)
+                {
+                    stopped.push(h);
+                }
+            }
+        } else {
+            stopped.extend(live.iter().map(|&(h, _)| h));
+        }
+    }
     /// `getCompleteBuffer` (cached, else decoded on the decoder thread) or
     /// `getStream` (decoded on a thread of its own), then attach and
     /// `alSourcePlay`. A sound that cannot load leaves its source initial,
@@ -822,18 +846,24 @@ impl Backend for MixerBackend {
 /// pinned client's) rendered through `ALC_SOFT_loopback` within 1e-5.
 fn stereo_gains(right: f32, up: f32, forward: f32) -> [f32; 2] {
     let length = (right * right + up * up + forward * forward).sqrt();
+    stereo_gains_with_length(right, up, forward, length)
+}
+#[inline]
+fn stereo_gains_with_length(right: f32, up: f32, forward: f32, length: f32) -> [f32; 2] {
     if length <= f32::EPSILON {
-        return stereo_gains(0.0, 0.0, 1.0);
+        return stereo_gains_with_length(0.0, 0.0, 1.0, 1.0);
     }
-    let elevation = (up / length).clamp(-1.0, 1.0).asin();
+    let u = (up / length).clamp(-1.0, 1.0);
+    let cos_elev = (1.0 - u * u).max(0.0).sqrt();
     let mut azimuth = right.atan2(forward);
     if azimuth.abs() < std::f32::consts::FRAC_PI_2 {
         azimuth = (azimuth.abs() * 1.5)
             .min(std::f32::consts::FRAC_PI_2)
             .copysign(azimuth);
     }
-    let side = azimuth.sin() * elevation.cos();
-    let front = azimuth.cos() * elevation.cos() * 0.095_660_8;
+    let (sin_az, cos_az) = azimuth.sin_cos();
+    let side = sin_az * cos_elev;
+    let front = cos_az * cos_elev * 0.095_660_8;
     [0.5 - 0.5 * side + front, 0.5 + 0.5 * side + front]
 }
 /// The gain OpenAL applies for distance (`AL_LINEAR_DISTANCE` with reference
@@ -853,16 +883,10 @@ fn mix(mixer: &mut Mixer, data: &mut [f32], channels: usize, rate: u32) {
     // and OpenAL's right = forward x up.
     let basis = |yaw: f32, pitch: f32| {
         let (yaw, pitch) = (f64::from(yaw.to_radians()), f64::from(pitch.to_radians()));
-        let forward = [
-            -yaw.sin() * pitch.cos(),
-            -pitch.sin(),
-            yaw.cos() * pitch.cos(),
-        ];
-        let up = [
-            -yaw.sin() * pitch.sin(),
-            pitch.cos(),
-            yaw.cos() * pitch.sin(),
-        ];
+        let (yaw_sin, yaw_cos) = yaw.sin_cos();
+        let (pitch_sin, pitch_cos) = pitch.sin_cos();
+        let forward = [-yaw_sin * pitch_cos, -pitch_sin, yaw_cos * pitch_cos];
+        let up = [-yaw_sin * pitch_sin, pitch_cos, yaw_cos * pitch_sin];
         let right = [
             forward[1] * up[2] - forward[2] * up[1],
             forward[2] * up[0] - forward[0] * up[2],
@@ -896,7 +920,7 @@ fn mix(mixer: &mut Mixer, data: &mut [f32], channels: usize, rate: u32) {
     // Gains and pans per source for this buffer.
     let mut voices = std::mem::take(&mut mixer.voices);
     voices.clear();
-    for (id, c) in &mixer.channels {
+    for (id, c) in &mut mixer.channels {
         let Some((_, source_rate, source_channels)) = &c.samples else {
             continue;
         };
@@ -907,6 +931,7 @@ fn mix(mixer: &mut Mixer, data: &mut [f32], channels: usize, rate: u32) {
         if c.state != State::Playing {
             continue;
         }
+
         let at = [f64::from(c.at[0]), f64::from(c.at[1]), f64::from(c.at[2])];
         let away = |listener: [f64; 3]| {
             [
@@ -915,45 +940,56 @@ fn mix(mixer: &mut Mixer, data: &mut [f32], channels: usize, rate: u32) {
                 at[2] - listener[2],
             ]
         };
-        let length = |d: [f64; 3]| d[0] * d[0] + d[1] * d[1] + d[2] * d[2];
-        // The nearest camera hears it (one camera but in splitscreen).
-        let camera = mixer
-            .cameras
-            .iter()
-            .filter(|camera| c.relative || camera.2 == c.world)
-            .min_by(|a, b| length(away(a.0)).total_cmp(&length(away(b.0))))
-            .map(|camera| (camera.0, camera.1));
-        // Unheard sources still advance: returning to a world must not resume stale sounds.
+        let length_sq = |d: [f64; 3]| d[0] * d[0] + d[1] * d[1] + d[2] * d[2];
+        let camera = if !shared {
+            let cam = &mixer.cameras[0];
+            if c.relative || cam.2 == c.world {
+                Some((cam.0, cam.1))
+            } else {
+                None
+            }
+        } else {
+            mixer
+                .cameras
+                .iter()
+                .filter(|camera| c.relative || camera.2 == c.world)
+                .min_by(|a, b| length_sq(away(a.0)).total_cmp(&length_sq(away(b.0))))
+                .map(|camera| (camera.0, camera.1))
+        };
         let (listener, (forward, up, right)) = camera.unwrap_or(([0.0; 3], basis(0.0, 0.0)));
         let d = if c.relative { at } else { away(listener) };
-        let distance = (d[0] * d[0] + d[1] * d[1] + d[2] * d[2]).sqrt() as f32;
-        let gain = if camera.is_some() {
-            c.gain.clamp(0.0, 1.0)
-                * if direct {
-                    1.0
-                } else {
-                    distance_gain(c.linear, distance)
+        let d_sqr = length_sq(d);
+
+        let (gain, [left, right]) = if camera.is_none() {
+            (0.0, [0.0, 0.0])
+        } else if direct {
+            let gain = c.gain.clamp(0.0, 1.0);
+            (gain, [gain, gain])
+        } else {
+            let mut zero = false;
+            if let Some(max) = c.linear {
+                let max_d = max as f64;
+                if max <= 0.0 || (!c.relative && d_sqr >= max_d * max_d) {
+                    zero = true;
                 }
-        } else {
-            0.0
-        };
-        let [left, right] = if direct {
-            [gain, gain]
-        } else {
-            // Relative sources are already in OpenAL's listener space (-Z ahead).
-            let [mut left, mut right] = if c.relative {
-                stereo_gains(d[0] as f32, d[1] as f32, -d[2] as f32)
-            } else {
-                stereo_gains(dot(d, right), dot(d, up), dot(d, forward))
-            };
-            if shared {
-                // Several players on the speakers: half the stereo width, as left and right are
-                // nobody's in particular.
-                let middle = (left + right) / 2.0;
-                left = middle + (left - middle) / 2.0;
-                right = middle + (right - middle) / 2.0;
             }
-            [left * gain, right * gain]
+            if zero {
+                (0.0, [0.0, 0.0])
+            } else {
+                let distance = d_sqr.sqrt() as f32;
+                let gain = c.gain.clamp(0.0, 1.0) * distance_gain(c.linear, distance);
+                let [mut left, mut right] = if c.relative {
+                    stereo_gains_with_length(d[0] as f32, d[1] as f32, -d[2] as f32, distance)
+                } else {
+                    stereo_gains_with_length(dot(d, right), dot(d, up), dot(d, forward), distance)
+                };
+                if shared {
+                    let middle = (left + right) * 0.5;
+                    left = middle + (left - middle) * 0.5;
+                    right = middle + (right - middle) * 0.5;
+                }
+                (gain, [left * gain, right * gain])
+            }
         };
         let step = f64::from(*source_rate) / f64::from(rate) * f64::from(c.pitch.max(0.0));
         voices.push((*id, [left, right, gain], step));
@@ -974,6 +1010,40 @@ fn mix(mixer: &mut Mixer, data: &mut [f32], channels: usize, rate: u32) {
         };
         let source_channels = source_channels as usize;
         let frames = samples.len() / source_channels;
+        let inaudible = if channels >= 2 {
+            left == 0.0 && right == 0.0
+        } else {
+            gain == 0.0
+        };
+        if inaudible {
+            let buffer_frames = data.len() / channels;
+            // As the loop below: a sound of one frame or none stops, looping or not.
+            if !c.looping || frames <= 1 {
+                // `frames` may be 0: no `frames - 1` in usize. A step of 0 never
+                // reaches the end, as in the loop below.
+                let needed = frames as f64 - 1.0 - c.position;
+                if needed <= 0.0 {
+                    c.state = State::Stopped;
+                } else if step > 0.0 {
+                    let steps_to_stop = needed / step;
+                    if (buffer_frames as f64) >= steps_to_stop {
+                        c.state = State::Stopped;
+                    } else {
+                        c.position += step * (buffer_frames as f64);
+                    }
+                }
+            } else {
+                for _ in 0..buffer_frames {
+                    let i = c.position as usize;
+                    if i + 1 >= frames {
+                        c.position = 0.0;
+                    }
+                    c.position += step;
+                }
+            }
+            continue;
+        }
+
         let out: &mut [f32] = if muffling && !c.unmuffled {
             &mut bus
         } else {
@@ -992,8 +1062,8 @@ fn mix(mixer: &mut Mixer, data: &mut [f32], channels: usize, rate: u32) {
             }
             let t = (c.position - i as f64) as f32;
             if source_channels > 1 {
-                let l = samples[i * 2] * (1.0 - t) + samples[(i + 1) * 2] * t;
-                let r = samples[i * 2 + 1] * (1.0 - t) + samples[(i + 1) * 2 + 1] * t;
+                let l = samples[i * 2] + (samples[(i + 1) * 2] - samples[i * 2]) * t;
+                let r = samples[i * 2 + 1] + (samples[(i + 1) * 2 + 1] - samples[i * 2 + 1]) * t;
                 if channels >= 2 {
                     frame[0] += l * left;
                     frame[1] += r * right;
@@ -1001,7 +1071,7 @@ fn mix(mixer: &mut Mixer, data: &mut [f32], channels: usize, rate: u32) {
                     frame[0] += (l + r) * 0.5 * gain;
                 }
             } else {
-                let s = samples[i] * (1.0 - t) + samples[i + 1] * t;
+                let s = samples[i] + (samples[i + 1] - samples[i]) * t;
                 if channels >= 2 {
                     frame[0] += s * left;
                     frame[1] += s * right;
@@ -1412,6 +1482,7 @@ impl Audio {
             record_heard: false,
             listener: [0.0; 3],
             listener_yaw: 0.0,
+            listener_pitch: 0.0,
             master: 1.0,
             random: crate::random_source::create(),
             source_override: None,
@@ -1535,8 +1606,12 @@ impl Audio {
     /// `SoundManager.updateSource`: the camera position and rotation
     /// (`Listener.setTransform` takes its forward and up vectors).
     pub fn set_listener(&mut self, position: [f64; 3], yaw: f32, pitch: f32) {
+        if self.listener == position && self.listener_yaw == yaw && self.listener_pitch == pitch {
+            return;
+        }
         self.listener = position;
         self.listener_yaw = yaw;
+        self.listener_pitch = pitch;
         if let Ok(mut m) = self.backend.mixer.lock() {
             if self.backend.owner == 0 {
                 m.listener = position;
@@ -1576,6 +1651,7 @@ impl Audio {
             record_heard: false,
             listener: [0.0; 3],
             listener_yaw: 0.0,
+            listener_pitch: 0.0,
             master: self.master,
             random: crate::random_source::create(),
             source_override: None,
@@ -2109,6 +2185,25 @@ impl Audio {
             })
             .collect()
     }
+    /// Mixes one buffer of audio into `data` (channels: 1 or 2, rate in Hz).
+    pub fn mix_buffer(&mut self, data: &mut [f32], channels: usize, rate: u32) {
+        if let Ok(mut m) = self.backend.mixer.lock() {
+            mix(&mut m, data, channels, rate);
+        }
+    }
+    #[doc(hidden)]
+    pub fn insert_cached_sound(&mut self, key: &str, samples: Vec<f32>, rate: u32, channels: u16) {
+        if let Ok(mut c) = self.backend.cache.lock() {
+            c.insert(
+                key.to_owned(),
+                Some((std::sync::Arc::new(samples), rate, channels)),
+            );
+        }
+    }
+    #[doc(hidden)]
+    pub fn backend_live_for_bench(&mut self) {
+        self.backend.live = true;
+    }
 }
 impl Sounds for Audio {
     fn engine(&mut self) -> &mut SoundEngine {
@@ -2613,6 +2708,25 @@ mod tests {
         assert_eq!(data, [0.0; 4], "returning must not resume the old one-shot");
     }
 
+    /// A sound of one frame or none, heard or not, looping or not, stops at its first
+    /// buffer as the mixing loop stops it: none stays playing (and holds its channel).
+    #[test]
+    fn sounds_too_short_to_mix_stop_even_unheard() {
+        for (samples, looping) in [(vec![], false), (vec![1.0], false), (vec![1.0], true)] {
+            let mut mixer = Mixer::default();
+            let mut source = channel(samples.clone(), None, [0.0; 3], looping);
+            source.gain = 0.0;
+            mixer.channels.insert(1, source);
+            let mut data = [0.0; 4];
+            mix(&mut mixer, &mut data, 2, 48_000);
+            assert_eq!(
+                mixer.channels[&1].state,
+                State::Stopped,
+                "{samples:?} {looping}"
+            );
+        }
+    }
+
     #[test]
     fn variants_of_one_sound_are_the_same_sound() {
         assert_eq!(

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

@@ -960,7 +960,7 @@ pub struct Scene<'a> {
     pub world: &'a World,
     pub sprites: &'a HashMap<String, Rect>,
     /// The packs' OptiFine emissive overlays of the sprites.
-    pub emissive: &'a horizon_optifine::emissive::Emissive,
+    pub emissive: &'a crate::entity_textures::Emissive,
     /// Atlas sprites that contain a texel with fractional alpha. Static
     /// geometry stays on the cutout pipeline; these models keep the blended
     /// entity path so resource packs retain their alpha behavior.
@@ -1039,7 +1039,7 @@ impl CacheOptions {
     }
 }
 /// The block-entity models and what is baked from them: vanilla's, or the packs' custom entity
-/// models over them ([`crate::block_entity_cem`]).
+/// models over them ([`crate::pack_hooks::PackFormats::block_entity_models`]).
 #[derive(Default)]
 pub struct BlockEntityShapes {
     models: HashMap<&'static str, ModelPart>,
@@ -1555,7 +1555,7 @@ impl BlockEntityRenderer {
     /// The models the packs under `root` give, their `.jem` files over vanilla's, for
     /// [`Self::set_shapes`] (a pack reload): vanilla's own, shared, without any.
     pub fn shapes_for(&self, root: &Path) -> Arc<BlockEntityShapes> {
-        match crate::block_entity_cem::reshape(root, &self.vanilla.models) {
+        match crate::pack_hooks::formats().block_entity_models(root, &self.vanilla.models) {
             Some((models, textures)) => Arc::new(BlockEntityShapes::new(models, textures)),
             None => self.vanilla.clone(),
         }
@@ -4768,7 +4768,8 @@ mod tests {
 
     #[test]
     fn a_chest_jem_reshapes_the_closed_chest_and_paints_its_texture() {
-        use crate::block_entity_cem::tests::{BOX, chest, pack};
+        use crate::pack_formats::block_entity_cem::tests::{BOX, chest, pack};
+        crate::pack_formats::install();
         let vanilla = Arc::new(BlockEntityShapes::new(
             HashMap::from([("chest", chest())]),
             HashMap::new(),
@@ -4864,8 +4865,8 @@ mod tests {
         };
         // The chest's three faces become the bottom's, the lock's and the custom lid's six, in
         // the `.jem`'s texture. Ender and copper chests have no file of their own: vanilla's
-        // three faces in their own textures. (Trapped chests: `block_entity_cem`'s tests; their
-        // texture turns festive in late December.)
+        // three faces in their own textures. (Trapped chests: `block_entity_cem`'s tests in
+        // `pack_formats`; their texture turns festive in late December.)
         for (block, texture, u0, faces) in [
             ("chest", "entity/chest/normal", 0.4, 8),
             ("ender_chest", "entity/chest/ender", 0.2, 3),

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

@@ -1,116 +1,157 @@
-//! OptiFine's Custom Item Textures (and CIT Resewn's): the rules of the enabled packs'
-//! `optifine/cit/**/*.properties`, read from the overlay resource root. The rules themselves are
-//! `horizon_optifine::cit`'s.
+//! Custom item textures: rules a pack format vanilla doesn't read (OptiFine's and CIT Resewn's
+//! `cit/` folders) gives, which change a stack's texture, model, worn armour layers or
+//! enchantment glint. The platform's pack formats read and match them ([`crate::pack_hooks`]);
+//! the engine draws what the matching rule says ([`Rule`]).
 
-pub use horizon_optifine::cit::{Hand, Kind, Rule};
-
-use crate::cit_glint::{Global, StackGlint};
-use horizon_client_core::component::name_text;
-use horizon_client_core::scoreboard::comp_text;
-use horizon_items::item_data::{canon_tag, encode_components};
-use horizon_items::items::ItemStack;
-use horizon_optifine::cit::{ComponentTest, Source, ValueTest};
-use horizon_optifine::{Properties, properties_files_in};
-use horizon_world::nbt::{JavaString, Tag, parse_snbt};
-use std::borrow::Cow;
-use std::collections::HashMap;
-use std::fs;
-use std::hash::{DefaultHasher, Hash, Hasher};
 use std::path::Path;
-use std::sync::{Arc, Mutex};
+use std::sync::Arc;
 
-/// Every rule under the root's `optifine/cit/`, `mcpatcher/cit/` and CIT Resewn's
-/// `citresewn/cit/` folders, the one chosen first when several match first (`Rule::priority`).
-/// The pack's global `cit.properties` is not a rule.
-pub fn load_rules(root: &Path) -> Vec<Rule> {
-    let tops = ["optifine", "mcpatcher", "citresewn"];
-    let mut rules: Vec<Rule> = properties_files_in(root, &tops, "cit")
-        .into_iter()
-        .filter(|path| !path.ends_with("/cit.properties"))
-        .filter_map(|path| {
-            let props = read_properties(&root.join(&path))?;
-            let rule = Rule::parse(&path, &props, |p| root.join(p).is_file());
-            if rule.is_none() {
-                log::warn!("custom item textures: {path} is not a rule Horizon can read");
-            }
-            rule
-        })
-        .collect();
-    rules.sort_by(Rule::priority);
-    rules
+use horizon_items::items::ItemStack;
+
+use crate::cit_glint::StackGlint;
+
+/// What a rule changes.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum Kind {
+    Item,
+    Armor,
+    Elytra,
+    Enchantment,
 }
 
-/// A `.properties` file as CIT Resewn reads them (`Properties::parse_equals_first`): UTF-8,
-/// else Latin-1 as Java reads them, so a pack saved that way still loads. `None` when it can't
-/// be read.
-pub fn read_properties(path: &Path) -> Option<Properties> {
-    let bytes = fs::read(path).ok()?;
-    let text = String::from_utf8(bytes)
-        .unwrap_or_else(|e| e.into_bytes().iter().map(|&b| char::from(b)).collect());
-    Some(Properties::parse_equals_first(&text))
+/// The hand a stack is drawn in; GUI items count as the main hand. `Any` is a rule's "either".
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum Hand {
+    Any,
+    Main,
+    Off,
 }
 
-/// The rules with an index by item and a cache of what each stack matched.
-#[derive(Debug, Default)]
+/// An OpenGL blend factor (`GL_ONE`, `GL_SRC_ALPHA`...), as `glBlendFuncSeparate` takes them.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum Factor {
+    Zero,
+    One,
+    SrcColor,
+    OneMinusSrcColor,
+    SrcAlpha,
+    OneMinusSrcAlpha,
+    DstAlpha,
+    OneMinusDstAlpha,
+    DstColor,
+    OneMinusDstColor,
+    SrcAlphaSaturate,
+}
+
+/// A glint layer's blend factors for colour and alpha.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub struct Blend {
+    pub src: Factor,
+    pub dst: Factor,
+    pub src_alpha: Factor,
+    pub dst_alpha: Factor,
+}
+
+/// An enchantment rule's glint layer.
+#[derive(Clone, Debug, PartialEq)]
+pub struct Glint {
+    pub layer: i32,
+    /// `None` draws without blending (replace).
+    pub blend: Option<Blend>,
+    /// Scroll speed: the texture runs through vanilla's glint periods at `speed` times the
+    /// clock in milliseconds.
+    pub speed: f32,
+    /// Degrees the texture turns by.
+    pub rotation: f32,
+    /// Seconds on this layer when the layers take turns.
+    pub duration: f32,
+    /// Multipliers of the texture's colour, never negative.
+    pub rgba: [f32; 4],
+    /// Whether the default glint still draws under this layer.
+    pub use_glint: bool,
+    /// Linear filtering, else nearest.
+    pub blur: bool,
+}
+
+/// A rule as the engine draws it.
+#[derive(Clone, Debug, PartialEq)]
+pub struct Rule {
+    /// The rule's file, as a resource path.
+    pub path: String,
+    pub kind: Kind,
+    /// Its texture, as a resource path to a `.png`.
+    pub texture: Option<String>,
+    /// Its named textures: (name, resource path).
+    pub textures: Vec<(String, String)>,
+    /// Its model, as a resource path to a `.json`.
+    pub model: Option<String>,
+    /// Its named models.
+    pub models: Vec<(String, String)>,
+    /// What an Enchantment rule draws.
+    pub glint: Glint,
+}
+
+/// Which rules a stack matches: the pack format's own conditions.
+pub trait Matcher: Send + Sync {
+    /// The winning rule of `kind` (Item, Armor or Elytra) for this stack, as an index into
+    /// [`CitRules::rules`].
+    fn select(&self, kind: Kind, stack: &ItemStack, hand: Hand, max_damage: u32) -> Option<usize>;
+    /// Every matching Enchantment rule for the stack drawn in `hand`, in priority order.
+    fn enchantments(&self, stack: &ItemStack, hand: Hand, max_damage: u32) -> Vec<usize>;
+    /// The glint layers this stack draws in `hand`; `None` when the pack changes no glint.
+    /// `foil` is whether the stack draws a glint at all.
+    fn glint(
+        &self,
+        stack: &ItemStack,
+        hand: Hand,
+        max_damage: u32,
+        foil: bool,
+    ) -> Option<Arc<StackGlint>>;
+    /// Leave out the Enchantment rules `keep` refuses: they match no stack.
+    fn keep_glints(&mut self, keep: &dyn Fn(usize) -> bool);
+}
+
+/// The packs' custom item texture rules, the winner first, and their matcher.
 pub struct CitRules {
     pub rules: Vec<Rule>,
-    /// The pack's `cit.properties`.
-    pub global: Global,
-    /// Per kind (`Kind as usize`), the rules naming each item, in priority order.
-    by_item: [HashMap<String, Vec<u32>>; 4],
-    /// Enchantment rules without `items`, in priority order.
-    any_item: Vec<u32>,
-    /// Per rule, per component test: its literal read as SNBT and as a JSON text component.
-    literals: Vec<Vec<Prepared>>,
-    selected: Mutex<HashMap<u64, Option<u32>>>,
-    enchanted: Mutex<HashMap<u64, Vec<u32>>>,
-    glints: Mutex<HashMap<u64, Arc<StackGlint>>>,
+    /// Whether the default glint draws on items no enchantment rule matches.
+    pub use_glint: bool,
+    matcher: Option<Box<dyn Matcher>>,
 }
 
-#[derive(Debug, Default)]
-struct Prepared {
-    snbt: Option<Tag>,
-    json: Option<String>,
-}
-
-/// Cache entries kept before the cache starts over.
-const CACHE_LIMIT: usize = 4096;
-
-impl CitRules {
-    /// The enabled packs' rules under the overlay resource root.
-    pub fn load(root: &Path) -> Self {
+impl Default for CitRules {
+    fn default() -> Self {
         Self {
-            global: crate::cit_glint::load_global(root),
-            ..Self::new(load_rules(root))
+            rules: Vec::new(),
+            use_glint: true,
+            matcher: None,
         }
     }
+}
 
-    /// `rules` in priority order, the winner first.
-    pub fn new(rules: Vec<Rule>) -> Self {
-        let mut by_item: [HashMap<String, Vec<u32>>; 4] = Default::default();
-        let mut any_item = Vec::new();
-        for (i, rule) in rules.iter().enumerate() {
-            let i = i as u32;
-            if rule.kind == Kind::Enchantment && rule.items.is_empty() {
-                any_item.push(i);
-            }
-            for item in &rule.items {
-                let list = by_item[rule.kind as usize].entry(item.clone()).or_default();
-                if list.last() != Some(&i) {
-                    list.push(i);
-                }
-            }
-        }
-        let literals = rules
-            .iter()
-            .map(|r| r.components.iter().map(prepare).collect())
-            .collect();
+impl std::fmt::Debug for CitRules {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("CitRules")
+            .field("rules", &self.rules)
+            .field("use_glint", &self.use_glint)
+            .finish_non_exhaustive()
+    }
+}
+
+impl CitRules {
+    /// The rules of the overlay at `root`, from the installed pack formats.
+    pub fn load(root: &Path) -> Self {
+        crate::pack_hooks::formats()
+            .item_textures(root)
+            .unwrap_or_default()
+    }
+
+    /// `rules`, in priority order, matched by `matcher`.
+    pub fn new(rules: Vec<Rule>, use_glint: bool, matcher: Box<dyn Matcher>) -> Self {
         Self {
             rules,
-            by_item,
-            any_item,
-            literals,
-            ..Default::default()
+            use_glint,
+            matcher: Some(matcher),
         }
     }
 
@@ -121,17 +162,12 @@ impl CitRules {
     /// Leave out the Enchantment rules `keep` refuses (those without a drawable texture): they
     /// match no stack, so vanilla's glint and the other rules of their layer stay.
     pub fn keep_glints(&mut self, keep: impl Fn(usize) -> bool) {
-        self.any_item.retain(|&i| keep(i as usize));
-        let named = &mut self.by_item[Kind::Enchantment as usize];
-        for list in named.values_mut() {
-            list.retain(|&i| keep(i as usize));
+        if let Some(matcher) = &mut self.matcher {
+            matcher.keep_glints(&keep);
         }
-        named.retain(|_, list| !list.is_empty());
-        lock(&self.enchanted).clear();
-        lock(&self.glints).clear();
     }
 
-    /// The winning rule of `kind` (Item, Armor or Elytra) for this stack, as an index into `rules`.
+    /// [`Matcher::select`].
     pub fn select(
         &self,
         kind: Kind,
@@ -139,51 +175,17 @@ impl CitRules {
         hand: Hand,
         max_damage: u32,
     ) -> Option<usize> {
-        let candidates = self.by_item[kind as usize].get(&*stack.item)?;
-        let comps = encode_components(stack);
-        let key = cache_key((0, kind, hand), stack, max_damage, comps.as_ref());
-        if let Some(hit) = lock(&self.selected).get(&key) {
-            return hit.map(|i| i as usize);
-        }
-        let found = candidates
-            .iter()
-            .copied()
-            .find(|&i| self.matches(i, stack, hand, max_damage, comps.as_ref()));
-        remember(&self.selected, key, found);
-        found.map(|i| i as usize)
+        self.matcher.as_ref()?.select(kind, stack, hand, max_damage)
     }
 
-    /// Every matching Enchantment rule for the stack drawn in `hand` (`Hand::Main` for one in a
-    /// GUI), in priority order.
+    /// [`Matcher::enchantments`].
     pub fn enchantments(&self, stack: &ItemStack, hand: Hand, max_damage: u32) -> Vec<usize> {
-        let named = self.by_item[Kind::Enchantment as usize]
-            .get(&*stack.item)
-            .map_or(&[][..], Vec::as_slice);
-        if named.is_empty() && self.any_item.is_empty() {
-            return Vec::new();
-        }
-        let comps = encode_components(stack);
-        let key = cache_key(
-            (1, Kind::Enchantment, hand),
-            stack,
-            max_damage,
-            comps.as_ref(),
-        );
-        let hit = lock(&self.enchanted).get(&key).cloned();
-        let found = hit.unwrap_or_else(|| {
-            let mut all: Vec<u32> = named.iter().chain(&self.any_item).copied().collect();
-            all.sort_unstable();
-            all.retain(|&i| self.matches(i, stack, hand, max_damage, comps.as_ref()));
-            remember(&self.enchanted, key, all.clone());
-            all
-        });
-        found.into_iter().map(|i| i as usize).collect()
+        self.matcher
+            .as_ref()
+            .map_or_else(Vec::new, |m| m.enchantments(stack, hand, max_damage))
     }
 
-    /// The glint layers this stack draws in `hand` (`Hand::Main` in a GUI) and whether
-    /// vanilla's still does (`StackGlint`), worked out once per stack and hand; `None` when the
-    /// pack changes no glint. `foil` is whether the stack draws a glint at all
-    /// (`ItemStack::has_foil`): one that doesn't gets no layers.
+    /// [`Matcher::glint`].
     pub fn glint(
         &self,
         stack: &ItemStack,
@@ -191,659 +193,6 @@ impl CitRules {
         max_damage: u32,
         foil: bool,
     ) -> Option<Arc<StackGlint>> {
-        let no_rules =
-            self.any_item.is_empty() && self.by_item[Kind::Enchantment as usize].is_empty();
-        // Before the cache, which `foil` is not part of.
-        if !foil || (no_rules && self.global.use_glint) {
-            return None;
-        }
-        let comps = encode_components(stack);
-        let key = cache_key(
-            (2, Kind::Enchantment, hand),
-            stack,
-            max_damage,
-            comps.as_ref(),
-        );
-        if let Some(hit) = lock(&self.glints).get(&key) {
-            return Some(hit.clone());
-        }
-        let matched = self.enchantments(stack, hand, max_damage);
-        let glint = Arc::new(StackGlint::new(
-            &self.rules,
-            &matched,
-            stack.crafting_enchantments(),
-            &self.global,
-        ));
-        remember(&self.glints, key, glint.clone());
-        Some(glint)
-    }
-
-    /// Whether rule `i` matches the stack drawn in `hand`.
-    fn matches(
-        &self,
-        i: u32,
-        stack: &ItemStack,
-        hand: Hand,
-        max_damage: u32,
-        comps: Option<&Tag>,
-    ) -> bool {
-        let rule = &self.rules[i as usize];
-        if rule.hand != Hand::Any && rule.hand != hand {
-            return false;
-        }
-        let count = i32::try_from(stack.count).unwrap_or(i32::MAX);
-        if rule.stack_size.as_ref().is_some_and(|r| !r.contains(count)) {
-            return false;
-        }
-        // CIT Resewn: only damageable items have damage.
-        let damage = if max_damage > 0 { stack.damage } else { 0 };
-        if rule
-            .damage
-            .as_ref()
-            .is_some_and(|d| !d.matches(damage, max_damage))
-        {
-            return false;
-        }
-        let enchantments = stack.crafting_enchantments();
-        let listed = |id: &str| rule.enchantments.iter().any(|e| e == id);
-        if !rule.enchantments.is_empty() && !enchantments.iter().any(|(id, _)| listed(id)) {
-            return false;
-        }
-        if let Some(levels) = &rule.enchantment_levels {
-            let level_in_range = enchantments.iter().any(|(id, level)| {
-                (rule.enchantments.is_empty() || listed(id))
-                    && levels.contains(i32::try_from(*level).unwrap_or(i32::MAX))
-            });
-            if !level_in_range {
-                return false;
-            }
-        }
-        let literals = &self.literals[i as usize];
-        rule.components
-            .iter()
-            .zip(literals)
-            .all(|(test, lit)| component_test(test, lit, stack, comps) != test.negate)
-    }
-}
-
-fn lock<T>(m: &Mutex<T>) -> std::sync::MutexGuard<'_, T> {
-    m.lock().unwrap_or_else(|e| e.into_inner())
-}
-
-fn remember<V>(cache: &Mutex<HashMap<u64, V>>, key: u64, value: V) {
-    let mut cache = lock(cache);
-    if cache.len() >= CACHE_LIMIT {
-        cache.clear();
-    }
-    cache.insert(key, value);
-}
-
-/// What a cached answer depends on; `query` tells `select`, `enchantments` and `glint` apart.
-fn cache_key(query: (u8, Kind, Hand), stack: &ItemStack, max: u32, comps: Option<&Tag>) -> u64 {
-    let mut h = DefaultHasher::new();
-    (query.0, query.1 as u8, query.2 as u8, &*stack.item).hash(&mut h);
-    (stack.count, stack.damage, max, comps).hash(&mut h);
-    h.finish()
-}
-
-fn prepare(test: &ComponentTest) -> Prepared {
-    let ValueTest::Literal(lit) = &test.value else {
-        return Prepared::default();
-    };
-    let text = lit.text.trim();
-    let snbt = match parse_snbt(text) {
-        Ok((tag, read)) if read == text.len() && text.starts_with(['{', '[']) => Some(tag),
-        _ => None,
-    };
-    let json = json_plain(text);
-    Prepared { snbt, json }
-}
-
-/// The plain text of `s` read as a JSON text component.
-fn json_plain(s: &str) -> Option<String> {
-    if !s.starts_with(['{', '[', '"']) {
-        return None;
-    }
-    let value: serde_json::Value = serde_json::from_str(s).ok()?;
-    Some(comp_text(&value).plain())
-}
-
-/// Whether one test passes, before its `negate`.
-fn component_test(
-    test: &ComponentTest,
-    lit: &Prepared,
-    stack: &ItemStack,
-    comps: Option<&Tag>,
-) -> bool {
-    let legacy;
-    let (root, text_depth) = match &test.source {
-        Source::Component(id) => {
-            let depth = match id.as_str() {
-                "minecraft:custom_name" | "minecraft:item_name" => Some(0),
-                "minecraft:lore" => Some(1),
-                _ => None,
-            };
-            (comps.and_then(|c| c.get(id)), depth)
-        }
-        Source::LegacyEnchantments { stored } => {
-            let levels = if *stored {
-                stack.stored_enchantments()
-            } else {
-                stack.enchantments()
-            };
-            legacy = Tag::List(
-                levels
-                    .iter()
-                    .map(|(id, lvl)| {
-                        let lvl = i16::try_from(*lvl).unwrap_or(i16::MAX);
-                        Tag::compound([
-                            ("id", Tag::String((&**id).into())),
-                            ("lvl", Tag::Short(lvl)),
-                        ])
-                    })
-                    .collect(),
-            );
-            (Some(&legacy), None)
-        }
-    };
-    // Fields the component leaves out when 0, which pre-1.20.5 items always wrote.
-    let defaulted;
-    let root = match (&test.source, root, test.path.first()) {
-        (Source::Component(id), Some(Tag::Compound(map)), Some(field))
-            if matches!(
-                (id.as_str(), field.as_str()),
-                ("minecraft:written_book_content", "generation")
-                    | ("minecraft:fireworks", "flight_duration")
-            ) && !map.contains_key(&JavaString::from(field.as_str())) =>
-        {
-            let mut map = map.clone();
-            map.insert(JavaString::from(field.as_str()), Tag::Int(0));
-            defaulted = Tag::Compound(map);
-            Some(&defaulted)
-        }
-        (_, root, _) => root,
-    };
-    let Some(root) = root else {
-        return matches!(test.value, ValueTest::Exists(false));
-    };
-    if let ValueTest::Exists(want) = test.value {
-        return walk(root, &test.path, 0, &mut |_, _| true) == want;
-    }
-    walk(root, &test.path, 0, &mut |tag, depth| {
-        value_test(&test.value, lit, tag, text_depth == Some(depth))
-    })
-}
-
-/// Visits what `path` reaches from `tag`, true once `visit` is.
-fn walk(
-    tag: &Tag,
-    path: &[String],
-    depth: usize,
-    visit: &mut dyn FnMut(&Tag, usize) -> bool,
-) -> bool {
-    let Some((seg, rest)) = path.split_first() else {
-        return visit(tag, depth);
-    };
-    let mut next = |t: &Tag| walk(t, rest, depth + 1, visit);
-    let len = match tag {
-        Tag::Compound(map) if seg == "*" => return map.values().any(&mut next),
-        Tag::Compound(map) => return map.get(&JavaString::from(seg.as_str())).is_some_and(next),
-        Tag::List(v) => v.len(),
-        Tag::ByteArray(v) => v.len(),
-        Tag::IntArray(v) => v.len(),
-        Tag::LongArray(v) => v.len(),
-        _ => return false,
-    };
-    let element = |i: usize| match tag {
-        Tag::List(v) => Cow::Borrowed(&v[i]),
-        Tag::ByteArray(v) => Cow::Owned(Tag::Byte(v[i] as i8)),
-        Tag::IntArray(v) => Cow::Owned(Tag::Int(v[i])),
-        Tag::LongArray(v) => Cow::Owned(Tag::Long(v[i])),
-        _ => Cow::Owned(Tag::End),
-    };
-    if seg == "count" {
-        return next(&Tag::Int(i32::try_from(len).unwrap_or(i32::MAX)));
-    }
-    if seg == "*" {
-        return (0..len).any(|i| next(&element(i)));
-    }
-    seg.parse::<usize>()
-        .ok()
-        .filter(|&i| i < len)
-        .is_some_and(|i| next(&element(i)))
-}
-
-fn int_value(tag: &Tag) -> Option<i64> {
-    match *tag {
-        Tag::Byte(v) => Some(v.into()),
-        Tag::Short(v) => Some(v.into()),
-        Tag::Int(v) => Some(v.into()),
-        Tag::Long(v) => Some(v),
-        _ => None,
-    }
-}
-
-/// A number as Java's `String.valueOf` writes it (`3`, `3.0`).
-fn decimal(tag: &Tag) -> Option<String> {
-    let s = match *tag {
-        Tag::Float(b) => f32::from_bits(b).to_string(),
-        Tag::Double(b) => f64::from_bits(b).to_string(),
-        _ => return int_value(tag).map(|v| v.to_string()),
-    };
-    Some(if s.contains(['.', 'e', 'N', 'i']) {
-        s
-    } else {
-        s + ".0"
-    })
-}
-
-/// `text` against a string, its JSON text, or the plain text of a text component.
-fn text_matches(tag: &Tag, is_text: bool, text: impl Fn(&str) -> bool) -> bool {
-    match tag {
-        Tag::String(s) => {
-            let s = s.to_string_lossy();
-            text(&s)
-                || (is_text && text(&name_text(tag).plain()))
-                || json_plain(&s).is_some_and(|p| text(&p))
-        }
-        Tag::Compound(_) | Tag::List(_) => is_text && text(&name_text(tag).plain()),
-        _ => false,
-    }
-}
-
-fn value_test(test: &ValueTest, lit: &Prepared, tag: &Tag, is_text: bool) -> bool {
-    match test {
-        ValueTest::Exists(_) => true,
-        ValueTest::Range(r) => {
-            int_value(tag).is_some_and(|v| i32::try_from(v).is_ok_and(|v| r.contains(v)))
-        }
-        ValueTest::Raw(name) => name.matches(&canon_tag(tag)),
-        ValueTest::Text(name) => match decimal(tag) {
-            Some(n) => name.matches(&n),
-            None => text_matches(tag, is_text, |s| name.matches(s)),
-        },
-        ValueTest::Literal(l) => match tag {
-            Tag::Float(b) => l.text.trim().parse::<f32>().ok() == Some(f32::from_bits(*b)),
-            Tag::Double(b) => l.float == Some(f64::from_bits(*b)),
-            Tag::Compound(_) | Tag::List(_)
-                if lit.snbt.as_ref().is_some_and(|e| contains(e, tag)) =>
-            {
-                true
-            }
-            _ => match int_value(tag) {
-                Some(v) => l.int == Some(v),
-                None => text_matches(tag, is_text, |s| {
-                    s == l.text || lit.json.as_deref() == Some(s)
-                }),
-            },
-        },
-    }
-}
-
-/// `NbtUtils.compareNbt(expected, actual, true)`: every key and element of `expected` found in
-/// `actual`.
-fn contains(expected: &Tag, actual: &Tag) -> bool {
-    match (expected, actual) {
-        (Tag::Compound(e), Tag::Compound(a)) => e
-            .iter()
-            .all(|(k, v)| a.get(k).is_some_and(|a| contains(v, a))),
-        (Tag::List(e), Tag::List(a)) if e.is_empty() => a.is_empty(),
-        (Tag::List(e), Tag::List(a)) => e.iter().all(|e| a.iter().any(|a| contains(e, a))),
-        _ => expected == actual,
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use std::sync::Arc;
-
-    /// Rules from (file stem, properties), sorted as `load_rules` sorts them.
-    fn rules(files: &[(&str, &str)]) -> CitRules {
-        let mut rules: Vec<Rule> = files
-            .iter()
-            .map(|(stem, text)| {
-                let path = format!("assets/minecraft/optifine/cit/{stem}.properties");
-                let text = format!("texture=x\n{text}");
-                Rule::parse(&path, &Properties::parse_equals_first(&text), |_| true).unwrap()
-            })
-            .collect();
-        rules.sort_by(Rule::priority);
-        CitRules::new(rules)
-    }
-
-    fn stem(cit: &CitRules, i: Option<usize>) -> Option<&str> {
-        let path = &cit.rules[i?].path;
-        path.rsplit('/').next()?.strip_suffix(".properties")
-    }
-
-    fn item(cit: &CitRules, stack: ItemStack) -> Option<&str> {
-        stem(cit, cit.select(Kind::Item, &stack, Hand::Main, 0))
-    }
-
-    fn new(id: &str) -> ItemStack {
-        ItemStack::new(&format!("minecraft:{id}"), 1)
-    }
-
-    fn string(s: &str) -> Tag {
-        Tag::String(s.into())
-    }
-
-    fn with(id: &str, component: &str, tag: Tag) -> ItemStack {
-        let mut stack = new(id);
-        let component = format!("minecraft:{component}");
-        stack.data_mut().other.push((component, tag));
-        stack
-    }
-
-    fn enchanted(id: &str, levels: &[(&str, u32)]) -> ItemStack {
-        let mut stack = new(id);
-        let levels = levels
-            .iter()
-            .map(|(e, l)| (Arc::from(format!("minecraft:{e}")), *l));
-        stack.data_mut().enchantments = levels.collect();
-        stack
-    }
-
-    #[test]
-    fn heavier_rules_win_and_kinds_stay_apart() {
-        let cit = rules(&[
-            ("plain", "items=stick"),
-            ("heavy", "items=stick\nweight=2\nstackSize=2-"),
-            ("offhand", "items=stick\nweight=5\nhand=off"),
-            ("armor", "type=armor\nitems=stick"),
-            ("wings", "type=elytra"),
-        ]);
-        assert_eq!(item(&cit, new("stick")), Some("plain"));
-        assert_eq!(
-            item(&cit, ItemStack::new("minecraft:stick", 3)),
-            Some("heavy")
-        );
-        let pick = |kind, id, hand, max| stem(&cit, cit.select(kind, &new(id), hand, max));
-        assert_eq!(pick(Kind::Item, "stick", Hand::Off, 0), Some("offhand"));
-        assert_eq!(item(&cit, new("stone")), None);
-        assert_eq!(item(&cit, new("elytra")), None);
-        assert_eq!(pick(Kind::Elytra, "elytra", Hand::Main, 432), Some("wings"));
-        assert_eq!(pick(Kind::Armor, "stick", Hand::Main, 0), Some("armor"));
-    }
-
-    #[test]
-    fn names_match_by_their_plain_text() {
-        let cit = rules(&[
-            ("glob", "items=stick\nnbt.display.Name=ipattern:*sword"),
-            ("exact", "items=stone\ncomponents.custom_name=My Sword"),
-            ("json", "items=dirt\nnbt.display.Name=[\"My \",\"Sword\"]"),
-        ]);
-        let named = |id: &str, name: Tag| {
-            let mut stack = new(id);
-            stack.data_mut().custom_name = Some(name);
-            stack
-        };
-        let styled = Tag::compound([("text", string("My Sword")), ("color", string("red"))]);
-        assert_eq!(item(&cit, named("stick", styled.clone())), Some("glob"));
-        assert_eq!(item(&cit, named("stick", string("Blade"))), None);
-        assert_eq!(item(&cit, new("stick")), None);
-        assert_eq!(item(&cit, named("stone", styled.clone())), Some("exact"));
-        assert_eq!(item(&cit, named("dirt", styled)), Some("json"));
-    }
-
-    #[test]
-    fn lore_lines_and_list_counts() {
-        let cit = rules(&[
-            (
-                "any_line",
-                "items=stick\nnbt.display.Lore.*=ipattern:*legendary*",
-            ),
-            ("two_lines", "items=stone\ncomponents.lore.count=2"),
-        ]);
-        let bold = Tag::compound([("text", string("A LEGENDARY item")), ("bold", Tag::Byte(1))]);
-        let lore = Tag::List(vec![string("Common"), bold]);
-        assert_eq!(
-            item(&cit, with("stick", "lore", lore.clone())),
-            Some("any_line")
-        );
-        assert_eq!(item(&cit, with("stone", "lore", lore)), Some("two_lines"));
-        let one = Tag::List(vec![string("A legendary item")]);
-        assert_eq!(item(&cit, with("stone", "lore", one)), None);
-    }
-
-    #[test]
-    fn custom_data_existence_and_negation() {
-        let cit = rules(&[
-            (
-                "aote",
-                "items=stick\nweight=2\nnbt.ExtraAttributes.id=ASPECT_OF_THE_END",
-            ),
-            (
-                "not_hyp",
-                "items=stick\nweight=1\ncomponent.custom_data.ExtraAttributes.id=!HYP",
-            ),
-            ("unnamed", "items=stick\nnbt.display.Name=exists:false"),
-        ]);
-        let data = |id: &str| {
-            let attributes =
-                Tag::compound([("ExtraAttributes", Tag::compound([("id", string(id))]))]);
-            with("stick", "custom_data", attributes)
-        };
-        assert_eq!(item(&cit, data("ASPECT_OF_THE_END")), Some("aote"));
-        assert_eq!(item(&cit, data("MIDAS")), Some("not_hyp"));
-        assert_eq!(item(&cit, data("HYP")), Some("unnamed"));
-        let mut named = data("HYP");
-        named.data_mut().custom_name = Some(string("Hyperion"));
-        assert_eq!(item(&cit, named), None);
-    }
-
-    #[test]
-    fn legacy_enchantment_lists_and_model_data() {
-        let cit = rules(&[
-            (
-                "sharp",
-                "items=stick\nnbt.Enchantments.*.id=minecraft:sharpness\nnbt.Enchantments.0.lvl=5",
-            ),
-            ("cmd", "items=stone\nnbt.CustomModelData=3"),
-            (
-                "cmd_snbt",
-                "items=dirt\ncomponents.custom_model_data={floats:[3.0f]}",
-            ),
-        ]);
-        assert_eq!(
-            item(&cit, enchanted("stick", &[("sharpness", 5)])),
-            Some("sharp")
-        );
-        assert_eq!(item(&cit, enchanted("stick", &[("sharpness", 4)])), None);
-        let model = |id: &str, f: f32| {
-            let floats = Tag::List(vec![Tag::Float(f.to_bits()), Tag::Float(7f32.to_bits())]);
-            with(id, "custom_model_data", Tag::compound([("floats", floats)]))
-        };
-        assert_eq!(item(&cit, model("stone", 3.0)), Some("cmd"));
-        assert_eq!(item(&cit, model("stone", 3.5)), None);
-        assert_eq!(item(&cit, model("dirt", 3.0)), Some("cmd_snbt"));
-        assert_eq!(item(&cit, model("dirt", 2.0)), None);
-    }
-
-    #[test]
-    fn fields_left_out_at_zero_read_as_zero() {
-        let cit = rules(&[("zero", "items=firework_rocket\nnbt.Fireworks.Flight=0")]);
-        let mut rocket = new("firework_rocket");
-        rocket.data_mut().fireworks = Some((0, Vec::new()));
-        assert_eq!(item(&cit, rocket.clone()), Some("zero"));
-        rocket.data_mut().fireworks = Some((2, Vec::new()));
-        assert_eq!(item(&cit, rocket), None);
-    }
-
-    #[test]
-    fn damage_counts_only_for_damageable_items() {
-        let cit = rules(&[
-            ("worn", "items=diamond_sword\ndamage=50-100%"),
-            ("new", "items=stick\ndamage=0"),
-        ]);
-        let damaged = |id: &str, damage: u32, max: u32| {
-            let mut stack = new(id);
-            stack.damage = damage;
-            stem(&cit, cit.select(Kind::Item, &stack, Hand::Main, max))
-        };
-        // Half of 1561 is 780.5.
-        assert_eq!(damaged("diamond_sword", 780, 1561), None);
-        assert_eq!(damaged("diamond_sword", 781, 1561), Some("worn"));
-        assert_eq!(damaged("stick", 5, 0), Some("new"));
-    }
-
-    #[test]
-    fn enchantment_levels_and_rules_for_any_item() {
-        let cit = rules(&[
-            (
-                "sharp3",
-                "items=stick\nenchantments=sharpness\nenchantmentLevels=3-",
-            ),
-            ("any3", "items=stone\nenchantmentLevels=3-"),
-            ("glint", "type=enchantment\nenchantments=sharpness"),
-            (
-                "sword_glint",
-                "type=enchantment\nitems=diamond_sword\nweight=2",
-            ),
-        ]);
-        let mixed = [("sharpness", 2), ("unbreaking", 3)];
-        assert_eq!(item(&cit, enchanted("stick", &mixed)), None);
-        assert_eq!(
-            item(&cit, enchanted("stick", &[("sharpness", 4)])),
-            Some("sharp3")
-        );
-        assert_eq!(item(&cit, enchanted("stone", &mixed)), Some("any3"));
-        let glints = |stack: ItemStack| -> Vec<&str> {
-            let found = cit.enchantments(&stack, Hand::Main, 0).into_iter();
-            found.map(|i| stem(&cit, Some(i)).unwrap()).collect()
-        };
-        let sharp = [("sharpness", 1)];
-        assert_eq!(
-            glints(enchanted("diamond_sword", &sharp)),
-            ["sword_glint", "glint"]
-        );
-        assert_eq!(glints(enchanted("stick", &sharp)), ["glint"]);
-        assert!(glints(new("stick")).is_empty());
-        // Glints are never an item's texture.
-        assert_eq!(item(&cit, enchanted("diamond_sword", &sharp)), None);
-    }
-
-    /// `CitRules::glint` in the main hand, with the stack's own `has_foil` as callers pass it.
-    fn glint(cit: &CitRules, stack: &ItemStack, item_glint: bool) -> Option<Arc<StackGlint>> {
-        cit.glint(stack, Hand::Main, 0, stack.has_foil(item_glint))
-    }
-
-    /// `stack` with its `enchantment_glint_override` set to `on`.
-    fn overridden(mut stack: ItemStack, on: bool) -> ItemStack {
-        let flag = (
-            "minecraft:enchantment_glint_override".to_owned(),
-            Tag::Byte(on.into()),
-        );
-        stack.data_mut().other.push(flag);
-        stack
-    }
-
-    #[test]
-    fn a_stack_glint_reads_the_book_and_the_pack_file() {
-        let mut cit = rules(&[
-            ("sharp", "type=enchantment\nenchantments=sharpness"),
-            (
-                "keep",
-                "type=enchantment\nlayer=1\nuseGlint=true\nenchantments=mending",
-            ),
-        ]);
-        // An enchanted book's glint follows its stored enchantments.
-        let mut book = new("enchanted_book");
-        book.data_mut().stored_enchantments = vec![
-            (Arc::from("minecraft:sharpness"), 3),
-            (Arc::from("minecraft:mending"), 1),
-        ];
-        let book = glint(&cit, &book, true).unwrap();
-        let weights: Vec<_> = book.layers.iter().map(|l| l.weight).collect();
-        assert_eq!(weights, [0.75, 0.25]);
-        assert!(book.vanilla);
-        let plain = glint(&cit, &enchanted("stick", &[("sharpness", 1)]), false).unwrap();
-        assert_eq!(plain.layers.len(), 1);
-        assert!(!plain.vanilla);
-        // No enchantment rules: nothing changes, unless the pack turns vanilla's glint off.
-        let mut bare = rules(&[("stick", "items=stick")]);
-        assert!(glint(&bare, &overridden(new("stick"), true), false).is_none());
-        bare.global.use_glint = false;
-        assert!(
-            !glint(&bare, &overridden(new("stick"), true), false)
-                .unwrap()
-                .vanilla
-        );
-        cit.global.use_glint = false;
-        assert!(
-            glint(&cit, &overridden(new("stick"), true), false)
-                .unwrap()
-                .is_empty()
-        );
-    }
-
-    #[test]
-    fn only_a_stack_with_a_glint_gets_layers() {
-        let cit = rules(&[("any", "type=enchantment")]);
-        assert!(glint(&cit, &new("stick"), false).is_none());
-        // The override turns an enchanted stack's glint off, and an unenchanted one's on.
-        let off = overridden(enchanted("stick", &[("sharpness", 1)]), false);
-        assert!(glint(&cit, &off, false).is_none());
-        let on = glint(&cit, &overridden(new("stick"), true), false).unwrap();
-        let weights: Vec<_> = on.layers.iter().map(|l| l.weight).collect();
-        assert_eq!(
-            weights,
-            [1.0],
-            "nothing to share: the rule at full strength"
-        );
-        // The same stack, asked again without its glint, is not answered from the cache.
-        assert!(
-            cit.glint(&overridden(new("stick"), true), Hand::Main, 0, false)
-                .is_none()
-        );
-    }
-
-    #[test]
-    fn a_rule_left_out_of_the_glints_matches_nothing() {
-        let mut cit = rules(&[
-            ("broken", "type=enchantment\nitems=diamond_sword\nweight=1"),
-            ("shown", "type=enchantment"),
-        ]);
-        let sword = enchanted("diamond_sword", &[("sharpness", 1)]);
-        let layers = |cit: &CitRules| -> Vec<String> {
-            let glint = glint(cit, &sword, false).unwrap();
-            let stems = glint
-                .layers
-                .iter()
-                .map(|l| stem(cit, Some(l.rule)).unwrap());
-            stems.map(str::to_owned).collect()
-        };
-        // The heavier rule wins the layer, until its texture is missing.
-        assert_eq!(layers(&cit), ["broken"]);
-        let broken = (0..cit.rules.len())
-            .find(|&i| stem(&cit, Some(i)) == Some("broken"))
-            .unwrap();
-        cit.keep_glints(|i| i != broken);
-        assert_eq!(layers(&cit), ["shown"]);
-        assert_eq!(cit.enchantments(&sword, Hand::Main, 0).len(), 1);
-        // None left: vanilla's glint stays.
-        cit.keep_glints(|_| false);
-        assert!(glint(&cit, &sword, false).is_none());
-    }
-
-    #[test]
-    fn an_off_hand_layer_draws_only_in_the_off_hand() {
-        let cit = rules(&[
-            ("left", "type=enchantment\nlayer=1\nhand=off"),
-            ("both", "type=enchantment"),
-        ]);
-        let sword = enchanted("diamond_sword", &[("sharpness", 1)]);
-        let layers = |hand| -> Vec<&str> {
-            let glint = cit.glint(&sword, hand, 0, true).unwrap();
-            glint
-                .layers
-                .iter()
-                .map(|l| stem(&cit, Some(l.rule)).unwrap())
-                .collect()
-        };
-        assert_eq!(layers(Hand::Off), ["both", "left"]);
-        // Asked in this order, a cache keyed without the hand would answer as for the off hand.
-        assert_eq!(layers(Hand::Main), ["both"]);
+        self.matcher.as_ref()?.glint(stack, hand, max_damage, foil)
     }
 }

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

@@ -6,8 +6,8 @@
 //! chestplate, boots) and `entity/equipment/humanoid_leggings/diamond` (layer 2), so the layers
 //! are mapped back to the old names here. An elytra rule's `texture` replaces the wings'.
 
+use crate::cit::{Kind, Rule};
 use crate::cit_assets::{rule_sprites, sprite_id};
-use horizon_optifine::cit::{Kind, Rule};
 use std::collections::BTreeSet;
 
 /// The pre-1.21.2 armour texture name of an equipment asset's layer: `asset` (`minecraft:gold`
@@ -114,10 +114,9 @@ pub fn armor_sprites(rules: &[Rule]) -> BTreeSet<String> {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use horizon_optifine::Properties;
 
     fn rule(path: &str, text: &str) -> Rule {
-        Rule::parse(path, &Properties::parse_equals_first(text), |_| true).unwrap()
+        crate::pack_formats::cit::parse_rule(path, text).unwrap()
     }
 
     #[test]

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

@@ -5,8 +5,8 @@
 //! `horizon_cit:minecraft/optifine/cit/swords/flame`). A file already under `textures/` (or
 //! `models/`) keeps its vanilla id, so it is not packed twice.
 
+use crate::cit::{Kind, Rule};
 use horizon_assets::model::{CuboidModel, TextureSlot};
-use horizon_optifine::cit::{Kind, Rule};
 use std::collections::{BTreeMap, BTreeSet};
 use std::fs;
 use std::path::Path;
@@ -55,7 +55,7 @@ pub fn model_id(resource: &str) -> Option<String> {
 /// and for one that would leave the resource root (a pack model may write any id).
 pub fn resource(id: &str, ext: &str) -> Option<String> {
     let rest = id.strip_prefix(NAMESPACE)?.strip_prefix(':')?;
-    horizon_optifine::paths::valid(rest).then(|| format!("assets/{rest}.{ext}"))
+    stays_in_root(rest).then(|| format!("assets/{rest}.{ext}"))
 }
 
 /// Sprite ids the rules whose kind passes `keep` draw: their `texture` and `texture.<name>`
@@ -102,7 +102,14 @@ fn relative(file: &str, value: &str, ext: &str) -> Option<String> {
         .and_then(|r| r.strip_suffix('.'))
         .unwrap_or(rest);
     let path = format!("{dir}/{rest}.{ext}");
-    horizon_optifine::paths::valid(&path).then_some(path)
+    stays_in_root(&path).then_some(path)
+}
+
+/// Whether a resource path stays in the root: no `.`, `..` or empty segment, and no `\` (a
+/// separator on Windows, where `..\..` would climb).
+fn stays_in_root(path: &str) -> bool {
+    path.split('/')
+        .all(|segment| !matches!(segment, "" | "." | "..") && !segment.contains('\\'))
 }
 
 /// The id a relative value of the model at `file` names, as `CuboidModel::from_json` read it
@@ -294,11 +301,11 @@ mod tests {
             "base.json",
             r#"{"parent":"item/handheld","textures":{"layer2":"./glow.png"}}"#,
         );
-        let props =
-            horizon_optifine::Properties::parse_equals_first("items=stick\nmodel=./swords/flame");
-        let rule = Rule::parse("assets/minecraft/optifine/cit/a.properties", &props, |p| {
-            root.join(p).is_file()
-        })
+        let rule = crate::pack_formats::cit::parse_rule_in(
+            &root,
+            "assets/minecraft/optifine/cit/a.properties",
+            "items=stick\nmodel=./swords/flame",
+        )
         .unwrap();
         let models = load_models(&root, &[rule]);
         let _ = fs::remove_dir_all(&root);

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

@@ -1,26 +1,6 @@
-//! Custom Item Textures' enchantment glints (`type=enchantment`): which of a stack's matching
-//! rules draw, in which order and how strongly, and whether vanilla's glint still draws under
-//! them. The pack's `cit.properties` (`Global`) says how layers share an item.
-//!
-//! Written from OptiFine's `cit.properties` doc and CIT Resewn's (MIT) `TypeEnchantment` of
-//! before its 1.21.11 port, which implemented `method`, `cap` and `fade`: the sums and the
-//! cycle's fading follow it, except where noted.
-
-pub use horizon_optifine::cit::{Global, Method};
-
-use crate::cit::read_properties;
-use horizon_optifine::cit::Rule;
-use std::path::Path;
-
-/// The pack's global `cit.properties` under the overlay resource root: the first of
-/// `Global::PATHS` that exists, else the defaults.
-pub fn load_global(root: &Path) -> Global {
-    Global::PATHS
-        .iter()
-        .find_map(|path| read_properties(&root.join(path)))
-        .map(|props| Global::parse(&props))
-        .unwrap_or_default()
-}
+//! Custom item textures' enchantment glints: the layers a stack draws over (or instead of)
+//! vanilla's glint, and how strongly each draws over time. Which layers a stack gets is the pack
+//! format's ([`crate::cit::Matcher::glint`]); a layer's look is its rule's [`crate::cit::Glint`].
 
 /// One glint layer a stack draws.
 #[derive(Clone, Copy, Debug, PartialEq)]
@@ -33,6 +13,17 @@ pub struct GlintLayer {
     duration: f32,
 }
 
+impl GlintLayer {
+    /// Rule `rule`'s layer at `weight`, on for `duration` seconds when the layers take turns.
+    pub fn new(rule: usize, weight: f32, duration: f32) -> Self {
+        Self {
+            rule,
+            weight,
+            duration,
+        }
+    }
+}
+
 /// What a stack's glint is made of, worked out when the stack changes.
 #[derive(Clone, Debug, Default, PartialEq)]
 pub struct StackGlint {
@@ -45,84 +36,14 @@ pub struct StackGlint {
 }
 
 impl StackGlint {
-    /// The layers among `matched` (the stack's matching enchantment rules, in priority order,
-    /// as `CitRules::enchantments` gives them) that draw, for a stack with `enchantments`
-    /// (`ItemStack::crafting_enchantments`).
-    pub fn new(
-        rules: &[Rule],
-        matched: &[usize],
-        enchantments: &[(impl AsRef<str>, u32)],
-        global: &Global,
-    ) -> Self {
-        // The highest priority rule of each layer.
-        let mut layers: Vec<usize> = Vec::new();
-        for &i in matched {
-            let layer = rules[i].glint.layer;
-            if !layers.iter().any(|&j| rules[j].glint.layer == layer) {
-                layers.push(i);
-            }
-        }
-        layers.sort_by_key(|&i| rules[i].glint.layer);
-        let cycle = global.method == Method::Cycle;
-        // OptiFine's doc: `cap` is for `average` and `layered`, and keeps the topmost layers.
-        // `none`, which OptiFine lacks, is capped too, as CIT Resewn caps every method (it keeps
-        // the bottom layers, though, and caps cycles as well).
-        if let Some(cap) = global.cap.filter(|_| !cycle) {
-            let cap = usize::try_from(cap).unwrap_or(usize::MAX);
-            layers = layers.split_off(layers.len().saturating_sub(cap));
-        }
-        // CIT Resewn: any layer left asking for vanilla's glint keeps it, and the global
-        // `useGlint=false` removes it everywhere, as OptiFine's doc says too. `cap=0` leaves no
-        // custom layer, and vanilla's glint only if the pack's `useGlint` allows it.
-        let vanilla = global.use_glint
-            && (layers.is_empty() || layers.iter().any(|&i| rules[i].glint.use_glint));
-        // CIT Resewn: shares are against every enchantment of the stack, not only those the
-        // layers name.
-        let levels = enchantments.iter().map(|(_, level)| *level as f32);
-        let total = match global.method {
-            Method::Average => levels.sum::<f32>(),
-            Method::Layered => levels.fold(0.0, f32::max),
-            Method::None | Method::Cycle => 0.0,
-        };
-        let shared = matches!(global.method, Method::Average | Method::Layered);
-        let layers = layers
-            .into_iter()
-            .map(|i| {
-                let rule = &rules[i];
-                let named = &rule.enchantments;
-                let weight = if !shared || named.is_empty() {
-                    1.0
-                } else {
-                    // The highest level among the enchantments the rule names whose level also
-                    // passes its `enchantmentLevels` (CIT Resewn takes the first named one the
-                    // stack has, whatever its level).
-                    let in_range = |level: u32| {
-                        let level = i32::try_from(level).unwrap_or(i32::MAX);
-                        rule.enchantment_levels
-                            .as_ref()
-                            .is_none_or(|r| r.contains(level))
-                    };
-                    let level = enchantments
-                        .iter()
-                        .filter(|(id, level)| {
-                            let id: &str = id.as_ref();
-                            named.iter().any(|n| n == id) && in_range(*level)
-                        })
-                        .map(|(_, level)| *level as f32)
-                        .fold(0.0, f32::max);
-                    if total > 0.0 { level / total } else { 0.0 }
-                };
-                GlintLayer {
-                    rule: i,
-                    weight,
-                    duration: rule.glint.duration,
-                }
-            })
-            .collect();
+    /// `layers`, bottom first; `vanilla` whether vanilla's glint draws under them; `cycle_fade`
+    /// the seconds each layer fades into the next when they take turns, else `None` (each
+    /// draws at its weight).
+    pub fn from_parts(layers: Vec<GlintLayer>, vanilla: bool, cycle_fade: Option<f32>) -> Self {
         Self {
             layers,
             vanilla,
-            cycle_fade: cycle.then_some(global.fade),
+            cycle_fade,
         }
     }
 
@@ -179,208 +100,3 @@ fn cycle_intensity(layers: &[GlintLayer], fade: f32, index: usize, seconds: f64)
     // Not reached, as the last layer returns above; no layer rather than a panic.
     0.0
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use horizon_optifine::Properties;
-
-    const DIR: &str = "assets/minecraft/optifine/cit";
-
-    /// An enchantment rule named `name` with `text` after `type` and `texture`.
-    fn rule(name: &str, text: &str) -> Rule {
-        let text = format!("type=enchantment\ntexture=glint\n{text}");
-        let path = format!("{DIR}/{name}.properties");
-        Rule::parse(&path, &Properties::parse_equals_first(&text), |_| true).unwrap()
-    }
-
-    fn global(text: &str) -> Global {
-        Global::parse(&Properties::parse_equals_first(text))
-    }
-
-    fn rules_of(layers: &StackGlint) -> Vec<usize> {
-        layers.layers.iter().map(|l| l.rule).collect()
-    }
-
-    const SWORD: [(&str, u32); 2] = [("minecraft:sharpness", 3), ("minecraft:unbreaking", 1)];
-
-    #[test]
-    fn one_rule_per_layer_bottom_first() {
-        let rules = [
-            rule("a", "layer=2"),
-            rule("b", "layer=0"),
-            rule("c", "layer=2"),
-            rule("d", "layer=-1"),
-        ];
-        // Priority order a, b, c, d: c loses layer 2 to a.
-        let g = StackGlint::new(&rules, &[0, 1, 2, 3], &SWORD, &Global::default());
-        assert_eq!(rules_of(&g), [3, 1, 0]);
-        let g = StackGlint::new(&rules, &[2, 0], &SWORD, &Global::default());
-        assert_eq!(rules_of(&g), [2]);
-    }
-
-    #[test]
-    fn average_and_layered_shares() {
-        let rules = [
-            rule("sharp", "enchantments=sharpness smite"),
-            rule("unb", "layer=1\nenchantments=unbreaking"),
-            rule("any", "layer=2"),
-            rule("fire", "layer=3\nenchantments=fire_aspect"),
-        ];
-        let weights = |method: &str| {
-            let g = StackGlint::new(&rules, &[0, 1, 2, 3], &SWORD, &global(method));
-            g.layers.iter().map(|l| l.weight).collect::<Vec<_>>()
-        };
-        // Sharpness III and Unbreaking I: 3 / 4 and 1 / 4; against the highest, 3 / 3 and 1 / 3.
-        // A rule naming no enchantment is at full strength, one the stack lacks at none.
-        assert_eq!(weights("method=average"), [0.75, 0.25, 1.0, 0.0]);
-        assert_eq!(weights("method=layered"), [1.0, 1.0 / 3.0, 1.0, 0.0]);
-        assert_eq!(weights("method=cycle"), [1.0; 4]);
-        assert_eq!(weights("method=none"), [1.0; 4]);
-    }
-
-    #[test]
-    fn the_level_is_one_the_rules_levels_allow() {
-        let rules = [rule(
-            "holy",
-            "enchantments=sharpness smite\nenchantmentLevels=1-2",
-        )];
-        // Sharpness V is out of range, so Smite I sets the share: 1 / 5 of the highest level.
-        let stack = [("minecraft:sharpness", 5), ("minecraft:smite", 1)];
-        let g = StackGlint::new(&rules, &[0], &stack, &global("method=layered"));
-        assert_eq!(g.layers[0].weight, 1.0 / 5.0);
-    }
-
-    #[test]
-    fn cap_keeps_the_topmost_layers() {
-        let rules = [
-            rule("a", "layer=0"),
-            rule("b", "layer=1"),
-            rule("c", "layer=2"),
-        ];
-        let g = StackGlint::new(&rules, &[0, 1, 2], &SWORD, &global("cap=2"));
-        assert_eq!(rules_of(&g), [1, 2]);
-        let g = StackGlint::new(&rules, &[0, 1, 2], &SWORD, &global("cap=0"));
-        assert!(g.is_empty());
-        let g = StackGlint::new(&rules, &[0, 1, 2], &SWORD, &global("cap=1\nmethod=none"));
-        assert_eq!(rules_of(&g), [2]);
-        // Cycles show every layer in turn.
-        let g = StackGlint::new(&rules, &[0, 1, 2], &SWORD, &global("cap=1\nmethod=cycle"));
-        assert_eq!(rules_of(&g), [0, 1, 2]);
-    }
-
-    #[test]
-    fn vanilla_glint() {
-        let plain = rule("plain", "");
-        let keep = rule("keep", "layer=1\nuseGlint=true");
-        let rules = [plain, keep];
-        let vanilla = |matched: &[usize], text: &str| {
-            StackGlint::new(&rules, matched, &SWORD, &global(text)).vanilla
-        };
-        assert!(vanilla(&[], ""), "no rule: vanilla's glint");
-        assert!(!vanilla(&[0], ""), "a rule replaces it");
-        assert!(vanilla(&[0, 1], ""), "unless one keeps it");
-        assert!(!vanilla(&[], "useGlint=false"));
-        assert!(!vanilla(&[1], "useGlint=false"), "the pack's word is final");
-        // Only the layers `cap` keeps count.
-        let rules = [rule("keep", "useGlint=true"), rule("top", "layer=1")];
-        let g = StackGlint::new(&rules, &[0, 1], &SWORD, &global("cap=1"));
-        assert!(!g.vanilla);
-        let g = StackGlint::new(&rules, &[0, 1], &SWORD, &global("cap=0"));
-        assert!(g.is_empty() && g.vanilla);
-        let g = StackGlint::new(&rules, &[0, 1], &SWORD, &global("cap=0\nuseGlint=false"));
-        assert!(!g.vanilla);
-    }
-
-    #[test]
-    fn cycles_take_turns_and_fade() {
-        let rules = [
-            rule("a", "duration=2"),
-            rule("b", "layer=1\nduration=1"),
-            rule("c", "layer=2\nduration=1"),
-        ];
-        let g = StackGlint::new(
-            &rules,
-            &[0, 1, 2],
-            &SWORD,
-            &global("method=cycle\nfade=0.5"),
-        );
-        // a 0-2, a→b 2-2.5, b 2.5-3.5, b→c 3.5-4, c 4-5, c→a 5-5.5, then again.
-        let at = |t: f64| [0, 1, 2].map(|i| g.intensity(i, t));
-        assert_eq!(at(1.0), [1.0, 0.0, 0.0]);
-        assert_eq!(at(2.125), [0.75, 0.25, 0.0]);
-        assert_eq!(at(3.0), [0.0, 1.0, 0.0]);
-        assert_eq!(at(3.75), [0.0, 0.5, 0.5]);
-        assert_eq!(at(4.5), [0.0, 0.0, 1.0]);
-        assert_eq!(at(5.25), [0.5, 0.0, 0.5]);
-        assert_eq!(at(5.5 + 3.0), [0.0, 1.0, 0.0]);
-        // One layer always shows.
-        let one = StackGlint::new(&rules, &[1], &SWORD, &global("method=cycle"));
-        assert_eq!(one.intensity(0, 0.7), 1.0);
-    }
-
-    #[test]
-    fn a_cycle_always_shows_a_whole_layer() {
-        let rules = [
-            rule("a", "duration=0.1"),
-            rule("b", "layer=1\nduration=0.7"),
-            rule("c", "layer=2\nduration=0.2"),
-        ];
-        let g = StackGlint::new(
-            &rules,
-            &[0, 1, 2],
-            &SWORD,
-            &global("method=cycle\nfade=0.3"),
-        );
-        // Every millisecond of the first two seconds, and just under a period, the last fade's
-        // end. (Rounding has not been seen to leave time past it; the last fade's clamp is
-        // defensive.)
-        let period: f64 = [0.1f32, 0.7, 0.2]
-            .map(|d| f64::from(d) + f64::from(0.3f32))
-            .iter()
-            .sum();
-        let last = f64::from_bits(period.to_bits() - 1);
-        for t in (0..2000_i32)
-            .map(|i| f64::from(i) * 0.001)
-            .chain([last, period + last])
-        {
-            let sum: f32 = (0..3).map(|i| g.intensity(i, t)).sum();
-            assert!((sum - 1.0).abs() < 1e-5, "{sum} at {t}");
-        }
-        // No time at all: the bottom layer alone, never NaN.
-        let still = [rule("a", "duration=0"), rule("b", "layer=1\nduration=0")];
-        let g = StackGlint::new(&still, &[0, 1], &SWORD, &global("method=cycle\nfade=0"));
-        for t in [0.0, 0.5, 7.25] {
-            assert_eq!([0, 1].map(|i| g.intensity(i, t)), [1.0, 0.0]);
-        }
-    }
-
-    #[test]
-    fn the_first_global_file_wins() {
-        let root = std::env::temp_dir().join(format!("horizon-cit-glint-{}", std::process::id()));
-        let _ = std::fs::remove_dir_all(&root);
-        assert_eq!(load_global(&root), Global::default());
-        let write = |path: &str, text: &[u8]| {
-            let file = root.join(path);
-            std::fs::create_dir_all(file.parent().unwrap()).unwrap();
-            std::fs::write(file, text).unwrap();
-        };
-        // Saved as Latin-1 (`é` is not UTF-8 alone), in the OptiFine doc's `cit/` folder.
-        write(
-            "assets/minecraft/optifine/cit/cit.properties",
-            b"# caf\xE9\nmethod=cycle",
-        );
-        assert_eq!(load_global(&root).method, Method::Cycle);
-        write("assets/minecraft/mcpatcher/cit.properties", b"method=none");
-        assert_eq!(load_global(&root).method, Method::Cycle);
-        write(
-            "assets/minecraft/optifine/cit.properties",
-            b"method=layered",
-        );
-        assert_eq!(load_global(&root).method, Method::Layered);
-        write("assets/minecraft/citresewn/cit.properties", b"cap=1");
-        let g = load_global(&root);
-        let _ = std::fs::remove_dir_all(&root);
-        assert_eq!((g.method, g.cap), (Method::Average, Some(1)));
-    }
-}

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

@@ -0,0 +1,271 @@
+//! Entity textures a pack format vanilla doesn't read changes (OptiFine's random entities, ETF's
+//! blinking and emissive textures): the variants of each texture and how an entity picks one,
+//! the blink frames a texture shows now and then, and the overlays that glow over a texture.
+//! The platform's pack formats fill them once per pack load ([`crate::pack_hooks`]); drawing
+//! only looks them up in these tables.
+//!
+//! Textures have the names the entity atlas gives them (`entity/zombie/zombie`,
+//! `<ns>:<path>`); files outside `textures/` are listed with the name they take
+//! ([`RandomTextures::files`], [`Blinks::files`], [`Emissive::files`]) for the atlas to pack.
+
+use std::collections::{BTreeMap, HashMap};
+use std::path::Path;
+
+/// A pack's entity texture changes: variants, blinks and emissive overlays.
+#[derive(Debug, Default)]
+pub struct EntityTextures {
+    pub random: RandomTextures,
+    pub blinks: Blinks,
+    pub emissive: Emissive,
+}
+
+impl EntityTextures {
+    /// The changes of the overlay at `root`, from the installed pack formats.
+    pub fn load(root: &Path) -> Self {
+        crate::pack_hooks::formats()
+            .entity_textures(root)
+            .unwrap_or_default()
+    }
+}
+
+/// What a variant rule can ask about an entity. `None` is a fact the entity doesn't have (a
+/// creeper's profession): a rule asking for it doesn't match.
+#[derive(Clone, Debug, Default)]
+pub struct Facts<'a> {
+    /// Where the entity was first seen: its biome (`minecraft:plains`) and block height.
+    pub biome: Option<&'a str>,
+    pub y: Option<i32>,
+    /// The block it stood on and the block it stood in when first seen; empty when unknown.
+    pub blocks: &'a [Block<'a>],
+    /// Its custom name, with `§` formatting codes where the name has them.
+    pub name: Option<&'a str>,
+    /// Villager profession (`minecraft:farmer`) and level.
+    pub profession: Option<(&'a str, i32)>,
+    /// Collar, wool, carpet or shell colour, as a dye name (`light_blue`).
+    pub color: Option<&'a str>,
+    pub baby: Option<bool>,
+    /// Health and max health.
+    pub health: Option<(f32, f32)>,
+    /// When first seen: moon phase (0-7), time of day (0-23999) and weather.
+    pub moon_phase: Option<i32>,
+    pub day_time: Option<i32>,
+    pub weather: Option<Weather>,
+    /// Slime, magma cube or phantom size: 0 small, 1 medium, 3 big.
+    pub size: Option<i32>,
+}
+
+/// A block and the values of its state properties.
+#[derive(Clone, Copy, Debug)]
+pub struct Block<'a> {
+    pub id: &'a str,
+    pub states: &'a [(&'a str, &'a str)],
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum Weather {
+    Clear,
+    Rain,
+    Thunder,
+}
+
+/// How a pack format's rule files choose a variant.
+pub trait VariantRules: Send + Sync {
+    /// The variant rule file `rules` ([`Entry::rules`]) gives an entity with these facts and
+    /// seed, `None` when no rule matches.
+    fn matching(&self, rules: usize, facts: &Facts, seed: i32) -> Option<u32>;
+}
+
+/// Every texture a pack varies, by its atlas name.
+#[derive(Default)]
+pub struct RandomTextures {
+    entries: HashMap<String, Entry>,
+    /// Every variant's file (from the resource root) and atlas name.
+    files: Vec<(String, String)>,
+    rules: Option<Box<dyn VariantRules>>,
+    generation: u64,
+}
+
+impl std::fmt::Debug for RandomTextures {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("RandomTextures")
+            .field("entries", &self.entries)
+            .field("generation", &self.generation)
+            .finish_non_exhaustive()
+    }
+}
+
+/// One texture's variants.
+#[derive(Clone, Debug, Default, PartialEq)]
+pub struct Entry {
+    /// The rule file that chooses this texture's variant ([`RandomTextures::matching`]).
+    pub rules: Option<usize>,
+    /// The atlas name of each variant, by its number.
+    pub variants: BTreeMap<u32, String>,
+}
+
+impl RandomTextures {
+    /// `entries` by atlas name, their variants' `files` (file, atlas name), the rule files
+    /// `rules` that choose, and `generation`: different for every load (never 0), so choices
+    /// made from another load's rules are known to be stale.
+    pub fn new(
+        entries: HashMap<String, Entry>,
+        files: Vec<(String, String)>,
+        rules: Box<dyn VariantRules>,
+        generation: u64,
+    ) -> Self {
+        Self {
+            entries,
+            files,
+            rules: Some(rules),
+            generation,
+        }
+    }
+
+    /// This load's number; 0 for the empty set.
+    pub fn generation(&self) -> u64 {
+        self.generation
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.entries.is_empty()
+    }
+
+    /// The variants of the texture with this atlas name.
+    pub fn get(&self, texture: &str) -> Option<&Entry> {
+        self.entries.get(texture)
+    }
+
+    /// [`VariantRules::matching`].
+    pub fn matching(&self, rules: usize, facts: &Facts, seed: i32) -> Option<u32> {
+        self.rules.as_ref()?.matching(rules, facts, seed)
+    }
+
+    /// Every variant's file (its path from the resource root) and atlas name, for the entity
+    /// atlas to pack.
+    pub fn files(&self) -> impl Iterator<Item = (&str, &str)> {
+        self.files.iter().map(|(f, n)| (f.as_str(), n.as_str()))
+    }
+}
+
+impl Entry {
+    /// The atlas name of variant `index`, or `None` for the texture itself.
+    pub fn texture(&self, index: u32) -> Option<&str> {
+        self.variants.get(&index).map(String::as_str)
+    }
+
+    /// The even choice of an entity with this seed when no rules apply: the texture and its
+    /// variants 2, 3... up to the first missing one.
+    pub fn even(&self, seed: i32) -> u32 {
+        let mut count = 1;
+        while self.variants.contains_key(&(count + 1)) {
+            count += 1;
+        }
+        seed.unsigned_abs() % count + 1
+    }
+}
+
+/// An entity's seed from its UUID (most then least significant 64 bits): Java's
+/// `UUID.hashCode`, so it is fixed for the entity's whole life, on every client.
+pub fn seed(most: i64, least: i64) -> i32 {
+    let x = most ^ least;
+    ((x >> 32) ^ x) as i32
+}
+
+/// The pack's blinking textures, by the atlas name of the texture they replace.
+#[derive(Debug, Default)]
+pub struct Blinks {
+    blinks: HashMap<String, Blink>,
+    /// The blink frames outside `textures/`: file and atlas name.
+    files: Vec<(String, String)>,
+}
+
+/// A texture's blink.
+#[derive(Clone, Debug, PartialEq)]
+pub struct Blink {
+    /// The atlas names of the shut and half-shut frames.
+    pub shut: String,
+    pub half: Option<String>,
+    /// Ticks a blink lasts (at least 1) and ticks from one blink to the next (more).
+    pub length: u32,
+    pub frequency: u32,
+}
+
+impl Blinks {
+    /// `blinks` by the atlas name of the texture they replace, and the frames outside
+    /// `textures/` (file, atlas name).
+    pub fn new(blinks: HashMap<String, Blink>, files: Vec<(String, String)>) -> Self {
+        Self { blinks, files }
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.blinks.is_empty()
+    }
+
+    pub fn get(&self, texture: &str) -> Option<&Blink> {
+        self.blinks.get(texture)
+    }
+
+    /// The frames outside `textures/`: file and atlas name, for the entity atlas to pack (it
+    /// walks `textures/` itself).
+    pub fn files(&self) -> impl Iterator<Item = (&str, &str)> {
+        self.files.iter().map(|(f, n)| (f.as_str(), n.as_str()))
+    }
+}
+
+impl Blink {
+    /// The frame an entity shows `tick` ticks into its life: `None` with its eyes open. `phase`
+    /// spreads entities' blinks apart. With a half-shut frame, the first and last ticks of a
+    /// blink of 3 or more show it.
+    pub fn frame(&self, tick: u32, phase: u32) -> Option<&str> {
+        let t = (u64::from(tick) + u64::from(phase)) % u64::from(self.frequency);
+        let t = t as u32;
+        if t >= self.length {
+            return None;
+        }
+        match &self.half {
+            Some(half) if self.length >= 3 && (t == 0 || t == self.length - 1) => Some(half),
+            _ => Some(&self.shut),
+        }
+    }
+}
+
+/// The pack's emissive overlays, by the atlas name of the texture they glow over.
+#[derive(Debug, Default)]
+pub struct Emissive {
+    /// The name ending of the pack's emissive textures (`_e`).
+    pub suffix: String,
+    overlays: HashMap<String, String>,
+    /// Overlays outside `textures/`: file and atlas name.
+    files: Vec<(String, String)>,
+}
+
+impl Emissive {
+    /// `overlays` (texture → overlay, atlas names) with name ending `suffix`, and those outside
+    /// `textures/` (file, atlas name).
+    pub fn new(
+        suffix: String,
+        overlays: HashMap<String, String>,
+        files: Vec<(String, String)>,
+    ) -> Self {
+        Self {
+            suffix,
+            overlays,
+            files,
+        }
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.overlays.is_empty()
+    }
+
+    /// The atlas name of the overlay that glows over `texture`.
+    pub fn overlay(&self, texture: &str) -> Option<&str> {
+        self.overlays.get(texture).map(String::as_str)
+    }
+
+    /// The overlays outside `textures/`: file (from the resource root) and atlas name, for the
+    /// entity atlas to pack (it walks `textures/` itself).
+    pub fn files(&self) -> impl Iterator<Item = (&str, &str)> {
+        self.files.iter().map(|(f, n)| (f.as_str(), n.as_str()))
+    }
+}

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

@@ -265,7 +265,7 @@ impl horizon_polytone::expr::Host for FrameHost<'_> {
             ("config", [horizon_polytone::expr::Value::Str(id)]) => self
                 .configs
                 .get(id)
-                .map(horizon_polytone::pack::ConfigValue::to_value)
+                .map(horizon_polytone::pack::config_value)
                 .ok_or_else(|| format!("no config {id}")),
             _ => Err(format!(
                 "{name} is not available in an attribute expression"
@@ -569,6 +569,25 @@ pub(crate) fn polytone_noise() -> &'static horizon_core::noise::SimplexNoise {
 }
 
 impl horizon_polytone::expr::Host for BlockHost<'_> {
+    fn field(
+        &mut self,
+        root: horizon_polytone::expr::Root,
+        field: horizon_polytone::expr::Field,
+    ) -> Option<horizon_polytone::expr::Value> {
+        use horizon_polytone::expr::Field as F;
+        if root != horizon_polytone::expr::Root::Object {
+            return None;
+        }
+        Some(horizon_polytone::expr::Value::Num(match field {
+            F::X => f64::from(self.at[0]),
+            F::Y => f64::from(self.at[1]),
+            F::Z => f64::from(self.at[2]),
+            F::Temperature => f64::from(self.biome.temperature),
+            F::Downfall => f64::from(self.biome.downfall),
+            _ => return None,
+        }))
+    }
+
     fn root(&mut self, root: horizon_polytone::expr::Root) -> horizon_polytone::expr::Value {
         use horizon_polytone::expr::Root;
         horizon_polytone::expr::Value::Object(match root {
@@ -1084,6 +1103,7 @@ mod tests {
         for (path, text) in pack {
             write(&format!("pack/{path}"), text);
         }
+        crate::pack_formats::install();
         let modifiers = PackModifiers::read(&dir.join("pack")).with_configs(
             crate::packs::polytone_configs(&crate::packs::Source::Dir(dir.join("pack"))),
         );

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

@@ -112,7 +112,11 @@ fn add_sections(groups: &mut Vec<Group<ExtraRow>>) {
                     };
                     Row::new(id, lang::get(label), value)
                 }
-                added::Row::Button { label } => Row::new(id, lang::get(label), Value::Press),
+                added::Row::Button {
+                    label,
+                    active: true,
+                    ..
+                } => Row::new(id, lang::get(label), Value::Press),
                 added::Row::Key { label, key } => {
                     let key = crate::keybinds::display_name(&key).plain();
                     Row::new(id, lang::get(label), Value::Read(key))
@@ -490,9 +494,7 @@ mod tests {
             added::Place::HorizonSettings
         }
         fn rows(&self, rows: &mut Vec<added::Row>) {
-            rows.push(added::Row::Button {
-                label: "test.elsewhere.button",
-            });
+            rows.push(added::Row::button("test.elsewhere.button"));
         }
         fn act(&self, _: usize, _: Act) {}
     }

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

@@ -233,6 +233,8 @@ pub struct FogInputs<'a> {
     pub night_vision: f32,
     /// The packs' `environment` fog settings (Polytone's).
     pub environment: crate::pack_palette::Environment,
+    /// The packs' fluid modifiers' fog.
+    pub fluid_fog: crate::pack_palette::FluidFogs,
 }
 
 /// `FogRenderer.setupFog` + `computeFogColor`.
@@ -397,6 +399,24 @@ pub fn setup_fog(tables: &FogTables, state: &FogState, input: &FogInputs) -> Fog
             }
         }
     }
+    // A pack's fluid modifier over its fluid's fog, after everything else (wiki "Custom Colors").
+    let fluid = match input.fog_type {
+        FogType::Lava => input.fluid_fog.lava,
+        FogType::Water if input.blindness.is_none() && input.darkness.is_none() => {
+            input.fluid_fog.water
+        }
+        _ => None,
+    };
+    if let Some(f) = fluid {
+        if let Some(rgb) = f.color {
+            let [r, g, b] = self::rgb(rgb);
+            fog.color = [r, g, b, 1.0];
+        }
+        let end = fog.environmental_end * f.radius;
+        let start = end - (end - fog.environmental_start * f.radius) * f.fade;
+        (fog.environmental_start, fog.environmental_end) = (start, end);
+        (fog.sky_end, fog.cloud_end) = (end, end);
+    }
     let span = (rd / 10.0).clamp(4.0, 64.0);
     fog.render_distance_start = rd - span;
     fog.render_distance_end = rd;
@@ -495,6 +515,7 @@ mod tests {
             full_water_vision: false,
             night_vision: 0.0,
             environment: Default::default(),
+            fluid_fog: Default::default(),
         }
     }
     #[test]
@@ -611,6 +632,38 @@ mod tests {
         let kept = setup_fog(&tables, &state, &input).color;
         assert_eq!(&kept[..3], &[0.1, 0.2, 0.4]);
     }
+    #[test]
+    fn a_fluid_modifier_scales_and_colours_its_fog_last() {
+        let sky = Sky {
+            fog_start: 10.0,
+            fog_end: 96.0,
+            ..Sky::default()
+        };
+        let tables = FogTables {
+            water_fog_end: vec![1.0],
+        };
+        let mut input = inputs(&sky);
+        input.fog_type = FogType::Lava;
+        input.fire_resistance = true;
+        let vanilla = setup_fog(&tables, &FogState::default(), &input);
+        assert_eq!(
+            (vanilla.environmental_start, vanilla.environmental_end),
+            (0.0, 5.0)
+        );
+        input.fluid_fog.lava = Some(crate::pack_palette::FluidFog {
+            color: Some(0x00FF00),
+            radius: 2.0,
+            fade: 0.5,
+        });
+        let fog = setup_fog(&tables, &FogState::default(), &input);
+        assert_eq!(fog.color, [0.0, 1.0, 0.0, 1.0]);
+        // The end doubles; half the fade from 0 to 10 starts it at 5.
+        assert_eq!(
+            (fog.environmental_start, fog.environmental_end),
+            (5.0, 10.0)
+        );
+        assert_eq!((fog.sky_end, fog.cloud_end), (10.0, 10.0));
+    }
     fn inputs_with<'a>(
         input: &FogInputs<'a>,
         environment: crate::pack_palette::Environment,

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

@@ -201,6 +201,7 @@ pub use hdr::{Calibration as HdrCalibration, Output as HdrOutput};
 mod hold;
 pub use hold::WorldHold;
 pub use output::{DisplayReading, EffectiveOutput, FrameConfiguration, FrameRequest};
+pub use screenshot_save::Saved as SavedScreenshot;
 pub mod block_light;
 mod custom_sky;
 mod displace;
@@ -236,6 +237,7 @@ pub mod panorama;
 mod readback;
 mod resident;
 mod reuse;
+mod screenshot_save;
 mod stars;
 mod surface_setup;
 use surface_setup::{AdapterChoice, AdapterFailure, open_adapter, pick_adapter, set_up_surface};
@@ -1084,6 +1086,9 @@ pub struct ScreenshotRequest {
     /// F2's: drawn at the game's resolution (Resolution Scale above 100%) times
     /// `Renderer::screenshot_quality`, not the window's.
     pub scaled: bool,
+    /// Written on a thread of its own (F2's, the world icon's): its outcome comes back a
+    /// frame or a few later in `Renderer::saved_screenshots`, not `screenshot_result`.
+    pub background: bool,
 }
 /// A solid terrain pipeline without HDR output's lighting (terrain.wgsl's `HDR_LIGHTING`),
 /// for the frames HDR is off, and with it where the display offers HDR output: the
@@ -1578,6 +1583,9 @@ pub struct Renderer {
     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>,
+    /// `background` screenshots written since the caller last took them.
+    pub saved_screenshots: Vec<SavedScreenshot>,
+    screenshot_saves: screenshot_save::Saves,
     /// 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,
@@ -5077,6 +5085,7 @@ impl Renderer {
             ));
         }
         let world_primitives = world_primitives::WorldPrimitives::new(&device, frame_format);
+        let screenshot_saves = screenshot_save::Saves::new(&device);
         Ok(Self {
             display: None,
             reading: display,
@@ -5348,6 +5357,8 @@ impl Renderer {
             screenshot: None,
             screenshot_result: None,
             screenshot_hdr: None,
+            saved_screenshots: Vec::new(),
+            screenshot_saves,
             screenshot_quality: 1,
             screenshot_halvings: 0,
             gamma: 0.5,
@@ -7041,8 +7052,10 @@ impl Renderer {
         }
     }
     /// This renderer's output as applied, with what its destination offers and reports.
-    pub fn output(&self) -> &output::EffectiveOutput {
-        &self.output
+    pub fn output(&self) -> output::EffectiveOutput {
+        let native = self.native.as_ref().map(|n| n.frame.api);
+        self.output
+            .with_pack(self.shader_pack_kind() == Some("iris"), native)
     }
     /// What this renderer's display last reported: a renderer made again for the window
     /// starts from it (`Renderer::new`'s `display`).
@@ -7975,6 +7988,8 @@ impl Renderer {
         if self.device_lost() {
             return Err("the graphics device was lost".into());
         }
+        let saved = self.screenshot_saves.finished();
+        self.saved_screenshots.extend(saved);
         if let Some(request) = self.capture.take() {
             let result = self.write_capture(&request, frame);
             self.capture_result = Some(result.map_err(|e| e.to_string()));
@@ -8319,9 +8334,7 @@ impl Renderer {
         let taa = !frame.title
             && self.pack_post.as_ref().is_none_or(|p| p.1.is_none())
             && self.native.as_ref().is_none_or(|n| n.post.is_none());
-        let hdr_lighting = self.native.is_none()
-            && self.pack_post.as_ref().is_none_or(|p| p.1.is_none())
-            && std::env::var_os("HORIZON_HDR_LIGHTING").is_none_or(|v| v != "0");
+        let hdr_lighting = self.shader_pack_kind().is_none();
         if let Some(hdr) = &mut self.hdr {
             hdr.lighting = hdr_lighting && hdr.look;
         }
@@ -12044,24 +12057,18 @@ 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());
-                            self.screenshot_hdr = Some(hdr_path);
-                        }
-                        Err(e) => log::warn!(
-                            "Horizon renderer: HDR screenshot {}: {e}",
-                            hdr_path.display()
-                        ),
-                    }
+                let size = [self.config.width, self.config.height];
+                let hdr = hdr_readback
+                    .filter(|_| self.hdr.is_some())
+                    .map(|b| (hdr_screenshot_path(&request.path), b));
+                let shot = screenshot_save::Shot::new(&request, size, self.config.format, hdr);
+                if request.background {
+                    self.screenshot_saves.start(shot, buffer);
+                } else {
+                    let saved = screenshot_save::save_now(&self.device, shot, &buffer);
+                    self.screenshot_hdr = saved.hdr;
+                    self.screenshot_result = Some(saved.result);
                 }
-                self.screenshot_result = Some(
-                    self.write_screenshot(&request, &buffer)
-                        .map_err(|e| e.to_string()),
-                );
             }
         }
         // The frame's own waits for the submit thread (its queue writes and passes).
@@ -12664,96 +12671,22 @@ impl Renderer {
             let texture = copy.as_ref().unwrap_or(texture);
             Some((request, copy_frame(&self.device, encoder, texture, size)))
         } else {
-            self.screenshot_result = Some(Err(format!(
+            let error = format!(
                 "screenshots need a 32-bit surface format, not {:?}",
                 self.config.format
-            )));
+            );
+            if request.background {
+                self.saved_screenshots.push(screenshot_save::Saved {
+                    path: request.path,
+                    result: Err(error),
+                    hdr: None,
+                });
+            } else {
+                self.screenshot_result = Some(Err(error));
+            }
             None
         }
     }
-    /// The pixels `copy_frame` read back into `buffer`, 4 bytes each, row after row.
-    fn read_frame(&self, buffer: &wgpu::Buffer) -> Result<Vec<[u8; 4]>> {
-        let (sender, receiver) = std::sync::mpsc::channel();
-        buffer.map_async(wgpu::MapMode::Read, .., move |r| {
-            let _ = sender.send(r);
-        });
-        self.device
-            .poll(wgpu::PollType::wait_indefinitely())
-            .map_err(|e| e.to_string())?;
-        receiver
-            .recv()
-            .map_err(|e| e.to_string())?
-            .map_err(|e| e.to_string())?;
-        let (width, height, row) = (
-            self.config.width as usize,
-            self.config.height as usize,
-            padded_row(self.config.width) as usize,
-        );
-        let mut pixels = Vec::with_capacity(width * height);
-        {
-            let data = buffer.get_mapped_range(..).map_err(|e| e.to_string())?;
-            for y in 0..height {
-                pixels.extend_from_slice(data[y * row..y * row + width * 4].as_chunks::<4>().0);
-            }
-        }
-        buffer.unmap();
-        Ok(pixels)
-    }
-    fn write_screenshot(
-        &self,
-        request: &ScreenshotRequest,
-        buffer: &wgpu::Buffer,
-    ) -> Result<[u32; 2]> {
-        let bgra = matches!(
-            self.config.format.remove_srgb_suffix(),
-            wgpu::TextureFormat::Bgra8Unorm
-        );
-        let mut pixels = Vec::with_capacity((self.config.width * self.config.height * 4) as usize);
-        for px in self.read_frame(buffer)? {
-            let (r, b) = if bgra { (px[2], px[0]) } else { (px[0], px[2]) };
-            pixels.extend_from_slice(&[r, px[1], b, 255]);
-        }
-        // NativeImage.resizeSubRectTo on takeAutoScreenshot's grab: the icon
-        // is the frame's centre square averaged down to its size.
-        let (width, height, pixels) = match request.size {
-            Some(size) => (
-                size[0],
-                size[1],
-                square_downscale(&pixels, self.config.width, self.config.height, size),
-            ),
-            None => (self.config.width, self.config.height, pixels),
-        };
-        let mut encoder = png::Encoder::new(
-            std::io::BufWriter::new(std::fs::File::create(&request.path)?),
-            width,
-            height,
-        );
-        encoder.set_color(png::ColorType::Rgba);
-        encoder.set_depth(png::BitDepth::Eight);
-        encoder.write_header()?.write_image_data(&pixels)?;
-        Ok([width, height])
-    }
-    /// The HDR10 copy (`Hdr::capture`) as a 16-bit PNG tagged BT.2020 with PQ (cICP, PNG's
-    /// third edition), with the content light levels its pixels hold (cLLI), and
-    /// an ICC profile for the programs that don't read cICP (`hdr_icc`).
-    fn write_hdr_screenshot(&self, path: &std::path::Path, buffer: &wgpu::Buffer) -> Result<()> {
-        if self.hdr.is_none() {
-            return Ok(());
-        }
-        let pixels = hdr10_to_rgb16(&self.read_frame(buffer)?);
-        let mut info = png::Info::with_size(self.config.width, self.config.height);
-        info.color_type = png::ColorType::Rgb;
-        info.bit_depth = png::BitDepth::Sixteen;
-        info.icc_profile = Some(hdr_icc::profile().into());
-        let encoder =
-            png::Encoder::with_info(std::io::BufWriter::new(std::fs::File::create(path)?), info)?;
-        let mut writer = encoder.write_header()?;
-        // BT.2020 primaries, PQ, RGB, full range.
-        writer.write_chunk(png::chunk::cICP, &[9, 16, 0, 1])?;
-        writer.write_chunk(png::chunk::cLLI, &hdr_icc::content_light_levels(&pixels))?;
-        writer.write_image_data(&pixels)?;
-        Ok(())
-    }
 }
 /// `screenshots/2026-10-28_12.00.00.png` -> `screenshots/2026-10-28_12.00.00-hdr.png`.
 fn hdr_screenshot_path(path: &std::path::Path) -> PathBuf {

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

@@ -191,7 +191,7 @@ pub struct Hdr {
     pub masks: Masks,
     /// HDR lighting, whether Horizon lifts this frame's world: off under a Horizon shader pack
     /// that draws, while a `shaders/` pack's post or material stage runs (the pack's own),
-    /// with HDR Lighting (`look`) off, and with `HORIZON_HDR_LIGHTING=0`, to compare.
+    /// and with HDR Lighting (`look`) off.
     pub lighting: bool,
     /// The HDR Lighting setting: off, nothing in the world is lifted, light sources and the
     /// sun included, so the picture is SDR's on the HDR canvas.
@@ -1001,12 +1001,14 @@ impl Hdr {
     }
 }
 
-/// Horizon's icon (horizon-theme) as a 1-bit mask: its white strokes, one colour with hard
-/// edges, are the logo; everything else is not.
+/// The windows' icon (`window::set_icon_png`: Horizon's in the official game) as a 1-bit mask:
+/// its white strokes, one colour with hard edges, are the logo; everything else is not. No icon
+/// given: an empty mask.
 fn logo_mask(device: &wgpu::Device, queue: &wgpu::Queue) -> wgpu::TextureView {
     use wgpu::util::DeviceExt;
-    let (w, h, rgba) =
-        crate::hud::decode_bytes(horizon_theme::ICON_PNG).unwrap_or((1, 1, vec![0; 4]));
+    let (w, h, rgba) = horizon_client_input::window::icon_png()
+        .and_then(|png| crate::hud::decode_bytes(png).ok())
+        .unwrap_or((1, 1, vec![0; 4]));
     let mask: Vec<u8> = rgba
         .as_chunks::<4>()
         .0

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

@@ -144,6 +144,9 @@ pub struct EffectiveOutput {
     pub(crate) nits: [f32; 3],
     /// The HUD and menus' brightness, as a share of paper white: their nits over its.
     pub(crate) ui_brightness: f32,
+    /// The running shader pack lights the world itself: Horizon lifts none of it, so HDR
+    /// Lighting has nothing to switch (`with_pack`).
+    pub(crate) pack_lights: bool,
 }
 impl Default for EffectiveOutput {
     fn default() -> Self {
@@ -166,7 +169,22 @@ impl EffectiveOutput {
         },
         nits: [203.0, 1000.0, 0.0],
         ui_brightness: 1.0,
+        pack_lights: false,
     };
+    /// This output under the running shader pack: a `shaders/` one (`shaders`), or one of
+    /// Horizon's own of API `native`. Under a 0.1 pack on the 8- or 16-bit frame the last pass
+    /// still lifts the light sources and the sun its marks hold (`lifts_world` in
+    /// `Renderer::render`); under the rest Horizon lifts nothing.
+    pub(crate) fn with_pack(self, shaders: bool, native: Option<horizon_shader_api::Api>) -> Self {
+        let pack_lights = shaders
+            || native.is_some_and(|api| {
+                api != horizon_shader_api::Api::V0_1 || self.frame.format == super::LINEAR_FRAME
+            });
+        Self {
+            pack_lights,
+            ..self
+        }
+    }
     /// Whether the destination offers HDR output.
     pub fn hdr_offered(&self) -> bool {
         self.offered.is_some()
@@ -273,6 +291,7 @@ pub(crate) fn resolve_output(
         ],
         ui_brightness: settings.ui_nits(reading.luminance) as f32
             / settings.paper_white_nits(reading.luminance) as f32,
+        pack_lights: false,
     }
 }
 

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

@@ -0,0 +1,79 @@
+//! Hardware ray queries, only on request (#13780, after the #1180 spike): `HORIZON_RAY_TRACING=1`
+//! at startup asks the device for wgpu's `EXPERIMENTAL_RAY_QUERY` when the GPU has it. Nothing
+//! draws with it yet. Without the variable, and in a build without `horizon-extras` (a Horizon
+//! extra, docs/layers.md), the device is opened exactly as before.
+
+/// The ray query feature.
+const RAY_QUERY: wgpu::Features = wgpu::Features::EXPERIMENTAL_RAY_QUERY;
+
+/// Whether the player asked for ray tracing (the device needs the feature from its creation).
+fn requested() -> bool {
+    asked(std::env::var("HORIZON_RAY_TRACING").ok().as_deref())
+}
+
+/// Whether `HORIZON_RAY_TRACING` set to `var` asks for ray tracing: only in a `horizon-extras`
+/// build.
+fn asked(var: Option<&str>) -> bool {
+    cfg!(feature = "horizon-extras") && var == Some("1")
+}
+
+/// The features to request on `adapter`: ray queries, when asked for and offered.
+pub(super) fn features(adapter: &wgpu::Adapter) -> wgpu::Features {
+    let features = pick(requested(), adapter.features());
+    if requested() {
+        let info = adapter.get_info();
+        if features.is_empty() {
+            log::warn!(
+                "Horizon renderer: ray tracing asked for, but {} on {:?} has no hardware ray \
+                 queries; it stays off",
+                info.name,
+                info.backend
+            );
+        } else {
+            log::info!(
+                "Horizon renderer: ray queries on ({} on {:?})",
+                info.name,
+                info.backend
+            );
+        }
+    }
+    features
+}
+
+fn pick(requested: bool, offered: wgpu::Features) -> wgpu::Features {
+    if requested {
+        offered & RAY_QUERY
+    } else {
+        wgpu::Features::empty()
+    }
+}
+
+/// The device's opt-in to `features`' experimental ones.
+pub(super) fn experimental(features: wgpu::Features) -> wgpu::ExperimentalFeatures {
+    if features.contains(RAY_QUERY) {
+        horizon_hdr::experimental_features()
+    } else {
+        wgpu::ExperimentalFeatures::disabled()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn only_an_extras_build_asks_for_ray_tracing() {
+        assert_eq!(asked(Some("1")), cfg!(feature = "horizon-extras"));
+        assert!(!asked(None));
+        assert!(!asked(Some("0")));
+    }
+
+    #[test]
+    fn ray_queries_only_when_asked_and_offered() {
+        let all = wgpu::Features::all();
+        assert_eq!(pick(true, all), RAY_QUERY);
+        assert!(pick(false, all).is_empty());
+        assert!(pick(true, all - RAY_QUERY).is_empty());
+        assert!(!experimental(wgpu::Features::empty()).is_enabled());
+    }
+}

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

@@ -0,0 +1,321 @@
+//! Writing a screenshot's PNG once its frame is read back: on the render thread for the
+//! requests that want the result with the frame (an agent's, a `screenshot-sequence`'s),
+//! on a thread of its own for F2's and the world icon's (`ScreenshotRequest::background`).
+//! The render thread then neither waits for the GPU to finish the frame nor encodes the
+//! PNG, which at 4K or a Screenshot Quality above 1x froze the game for a second or more.
+use super::{ScreenshotRequest, hdr_icc, hdr10_to_rgb16, padded_row, square_downscale};
+use std::path::PathBuf;
+use std::sync::mpsc::{Receiver, Sender, channel};
+use std::time::Duration;
+
+/// What a frame's readback holds and where its PNG goes.
+pub(super) struct Shot {
+    pub path: PathBuf,
+    /// `ScreenshotRequest::size`: the world icon's square.
+    pub size: Option<[u32; 2]>,
+    /// The frame's size, which the readback's rows hold (padded to `padded_row`).
+    pub frame: [u32; 2],
+    /// Blue first (`Bgra8Unorm`), swapped to PNG's red first.
+    pub bgra: bool,
+    /// The HDR10 copy's readback and its PNG's path, beside the SDR one.
+    pub hdr: Option<(PathBuf, wgpu::Buffer)>,
+}
+impl Shot {
+    pub fn new(
+        request: &ScreenshotRequest,
+        frame: [u32; 2],
+        format: wgpu::TextureFormat,
+        hdr: Option<(PathBuf, wgpu::Buffer)>,
+    ) -> Self {
+        Self {
+            path: request.path.clone(),
+            size: request.size,
+            frame,
+            bgra: format.remove_srgb_suffix() == wgpu::TextureFormat::Bgra8Unorm,
+            hdr,
+        }
+    }
+}
+/// A written screenshot: its path, its size or the error, and the HDR copy written beside it.
+pub struct Saved {
+    pub path: PathBuf,
+    pub result: Result<[u32; 2], String>,
+    pub hdr: Option<PathBuf>,
+}
+/// Waits for `buffer`'s mapping on the render thread and writes the PNG there.
+pub(super) fn save_now(device: &wgpu::Device, shot: Shot, buffer: &wgpu::Buffer) -> Saved {
+    let (sender, receiver) = channel();
+    map(buffer, &sender);
+    if let Some((_, hdr)) = &shot.hdr {
+        map(hdr, &sender);
+    }
+    let waited = device
+        .poll(wgpu::PollType::wait_indefinitely())
+        .map_err(|e| e.to_string());
+    let count = 1 + usize::from(shot.hdr.is_some());
+    let mapped = waited.and_then(|_| wait_mapped(&receiver, count));
+    write(shot, buffer, mapped)
+}
+/// Screenshots being written on their thread.
+pub(super) struct Saves {
+    device: wgpu::Device,
+    sender: Sender<Saved>,
+    receiver: Receiver<Saved>,
+    in_flight: usize,
+}
+impl Saves {
+    pub fn new(device: &wgpu::Device) -> Self {
+        let (sender, receiver) = channel();
+        Self {
+            device: device.clone(),
+            sender,
+            receiver,
+            in_flight: 0,
+        }
+    }
+    /// Maps `buffer` (and the HDR copy's), whose copy was just submitted, and writes the
+    /// PNG on a thread of its own once the GPU has finished the frame.
+    pub fn start(&mut self, shot: Shot, buffer: wgpu::Buffer) {
+        let (mapped, on_mapped) = channel();
+        map(&buffer, &mapped);
+        if let Some((_, hdr)) = &shot.hdr {
+            map(hdr, &mapped);
+        }
+        let done = self.sender.clone();
+        let path = shot.path.clone();
+        let spawned = std::thread::Builder::new()
+            .name("Screenshot writer".into())
+            .spawn(move || {
+                let count = 1 + usize::from(shot.hdr.is_some());
+                let ready = wait_mapped(&on_mapped, count);
+                let _ = done.send(write(shot, &buffer, ready));
+            });
+        match spawned {
+            Ok(_) => {}
+            Err(e) => {
+                let _ = self.sender.send(Saved {
+                    path,
+                    result: Err(format!("no thread to write it: {e}")),
+                    hdr: None,
+                });
+            }
+        }
+        self.in_flight += 1;
+    }
+    /// The screenshots written since the last call. Polls the device so a finished frame's
+    /// mapping reaches its writer: the render thread never waits for it.
+    pub fn finished(&mut self) -> Vec<Saved> {
+        if self.in_flight == 0 {
+            return Vec::new();
+        }
+        let _ = self.device.poll(wgpu::PollType::Poll);
+        let saved: Vec<Saved> = self.receiver.try_iter().collect();
+        self.in_flight -= saved.len();
+        saved
+    }
+}
+impl Drop for Saves {
+    /// A screenshot taken right before quitting is still written whole.
+    fn drop(&mut self) {
+        let deadline = std::time::Instant::now() + Duration::from_secs(10);
+        while self.in_flight > 0 && std::time::Instant::now() < deadline {
+            let _ = self.device.poll(wgpu::PollType::Poll);
+            if let Ok(saved) = self.receiver.recv_timeout(Duration::from_millis(20)) {
+                log_saved(&saved);
+                self.in_flight -= 1;
+            }
+        }
+    }
+}
+fn log_saved(saved: &Saved) {
+    match &saved.result {
+        Ok(_) => log::info!("Saved screenshot to {}", saved.path.display()),
+        Err(e) => log::warn!("Horizon renderer: screenshot {}: {e}", saved.path.display()),
+    }
+}
+fn map(buffer: &wgpu::Buffer, mapped: &Sender<Result<(), String>>) {
+    let mapped = mapped.clone();
+    buffer.map_async(wgpu::MapMode::Read, .., move |r| {
+        let _ = mapped.send(r.map_err(|e| e.to_string()));
+    });
+}
+/// `count` mappings done, or the first one that failed. A frame the GPU never finishes
+/// (a lost device) gives up after a while instead of keeping its thread.
+fn wait_mapped(mapped: &Receiver<Result<(), String>>, count: usize) -> Result<(), String> {
+    for _ in 0..count {
+        mapped
+            .recv_timeout(Duration::from_secs(30))
+            .map_err(|_| "the frame never came back from the GPU".to_string())??;
+    }
+    Ok(())
+}
+/// The PNG (and the HDR copy's beside it) from the mapped readbacks.
+fn write(shot: Shot, buffer: &wgpu::Buffer, mapped: Result<(), String>) -> Saved {
+    let mut hdr_written = None;
+    let result = mapped.and_then(|()| {
+        if let Some((hdr_path, hdr_buffer)) = &shot.hdr {
+            let pixels = read_rows(hdr_buffer, shot.frame);
+            match pixels.and_then(|p| write_hdr_png(hdr_path, shot.frame, &p)) {
+                Ok(()) => {
+                    log::info!("Saved HDR screenshot to {}", hdr_path.display());
+                    hdr_written = Some(hdr_path.clone());
+                }
+                Err(e) => log::warn!(
+                    "Horizon renderer: HDR screenshot {}: {e}",
+                    hdr_path.display()
+                ),
+            }
+        }
+        let pixels = read_rows(buffer, shot.frame)?;
+        write_png(&shot, &pixels)
+    });
+    Saved {
+        path: shot.path,
+        result,
+        hdr: hdr_written,
+    }
+}
+/// The pixels `copy_frame` read back into the mapped `buffer`, 4 bytes each, row after
+/// row; unmaps it.
+fn read_rows(buffer: &wgpu::Buffer, [width, height]: [u32; 2]) -> Result<Vec<[u8; 4]>, String> {
+    let (width, height, row) = (width as usize, height as usize, padded_row(width) as usize);
+    let mut pixels = Vec::with_capacity(width * height);
+    {
+        let data = buffer.get_mapped_range(..).map_err(|e| e.to_string())?;
+        for y in 0..height {
+            pixels.extend_from_slice(data[y * row..y * row + width * 4].as_chunks::<4>().0);
+        }
+    }
+    buffer.unmap();
+    Ok(pixels)
+}
+fn write_png(shot: &Shot, frame: &[[u8; 4]]) -> Result<[u32; 2], String> {
+    let [frame_w, frame_h] = shot.frame;
+    let mut pixels = Vec::with_capacity(frame.len() * 4);
+    for px in frame {
+        let (r, b) = if shot.bgra {
+            (px[2], px[0])
+        } else {
+            (px[0], px[2])
+        };
+        pixels.extend_from_slice(&[r, px[1], b, 255]);
+    }
+    // NativeImage.resizeSubRectTo on takeAutoScreenshot's grab: the icon
+    // is the frame's centre square averaged down to its size.
+    let (width, height, pixels) = match shot.size {
+        Some(size) => (
+            size[0],
+            size[1],
+            square_downscale(&pixels, frame_w, frame_h, size),
+        ),
+        None => (frame_w, frame_h, pixels),
+    };
+    let file = std::fs::File::create(&shot.path).map_err(|e| e.to_string())?;
+    let mut encoder = png::Encoder::new(std::io::BufWriter::new(file), width, height);
+    encoder.set_color(png::ColorType::Rgba);
+    encoder.set_depth(png::BitDepth::Eight);
+    encoder
+        .write_header()
+        .and_then(|mut w| w.write_image_data(&pixels))
+        .map_err(|e| e.to_string())?;
+    Ok([width, height])
+}
+/// The HDR10 copy (`Hdr::capture`) as a 16-bit PNG tagged BT.2020 with PQ (cICP, PNG's
+/// third edition), with the content light levels its pixels hold (cLLI), and
+/// an ICC profile for the programs that don't read cICP (`hdr_icc`).
+fn write_hdr_png(
+    path: &std::path::Path,
+    [width, height]: [u32; 2],
+    frame: &[[u8; 4]],
+) -> Result<(), String> {
+    let pixels = hdr10_to_rgb16(frame);
+    let mut info = png::Info::with_size(width, height);
+    info.color_type = png::ColorType::Rgb;
+    info.bit_depth = png::BitDepth::Sixteen;
+    info.icc_profile = Some(hdr_icc::profile().into());
+    let file = std::fs::File::create(path).map_err(|e| e.to_string())?;
+    let written = png::Encoder::with_info(std::io::BufWriter::new(file), info)
+        .and_then(|encoder| encoder.write_header())
+        .and_then(|mut writer| {
+            // BT.2020 primaries, PQ, RGB, full range.
+            writer.write_chunk(png::chunk::cICP, &[9, 16, 0, 1])?;
+            writer.write_chunk(png::chunk::cLLI, &hdr_icc::content_light_levels(&pixels))?;
+            writer.write_image_data(&pixels)
+        });
+    written.map_err(|e| e.to_string())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn a_background_save_writes_the_png_off_the_render_thread() {
+        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 dir = std::env::temp_dir().join(format!("horizon-shot-{}", std::process::id()));
+        std::fs::create_dir_all(&dir).unwrap();
+        let path = dir.join("shot.png");
+        let [w, h] = [3u32, 2];
+        // A frame of blue-first pixels, each row padded as `copy_frame` reads them back.
+        let row = padded_row(w) as usize;
+        let mut bytes = vec![0u8; row * h as usize];
+        for y in 0..h as usize {
+            for x in 0..w as usize {
+                bytes[y * row + x * 4..][..4].copy_from_slice(&[10 * x as u8, 20, 200, 0]);
+            }
+        }
+        let source = wgpu::util::DeviceExt::create_buffer_init(
+            &device,
+            &wgpu::util::BufferInitDescriptor {
+                label: None,
+                contents: &bytes,
+                usage: wgpu::BufferUsages::COPY_SRC,
+            },
+        );
+        let buffer = device.create_buffer(&wgpu::BufferDescriptor {
+            label: None,
+            size: bytes.len() as u64,
+            usage: wgpu::BufferUsages::COPY_DST | wgpu::BufferUsages::MAP_READ,
+            mapped_at_creation: false,
+        });
+        let mut encoder = device.create_command_encoder(&Default::default());
+        encoder.copy_buffer_to_buffer(&source, 0, &buffer, 0, bytes.len() as u64);
+        queue.submit([encoder.finish()]);
+        let request = ScreenshotRequest {
+            path: path.clone(),
+            size: None,
+            scaled: false,
+            background: true,
+        };
+        let mut saves = Saves::new(&device);
+        saves.start(
+            Shot::new(&request, [w, h], wgpu::TextureFormat::Bgra8Unorm, None),
+            buffer,
+        );
+        let deadline = std::time::Instant::now() + Duration::from_secs(10);
+        let saved = loop {
+            if let Some(saved) = saves.finished().pop() {
+                break saved;
+            }
+            assert!(std::time::Instant::now() < deadline, "never written");
+            std::thread::sleep(Duration::from_millis(5));
+        };
+        assert_eq!(saved.path, path);
+        assert_eq!(saved.result, Ok([w, h]));
+        let decoder =
+            png::Decoder::new(std::io::BufReader::new(std::fs::File::open(&path).unwrap()));
+        let mut reader = decoder.read_info().unwrap();
+        let mut out = vec![0; reader.output_buffer_size().unwrap()];
+        reader.next_frame(&mut out).unwrap();
+        // Red first, opaque: the last pixel of the first row was [20, 20, 200] blue-first.
+        assert_eq!(&out[8..12], &[200, 20, 20, 255]);
+        std::fs::remove_dir_all(&dir).unwrap();
+    }
+}

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

@@ -5,6 +5,9 @@ use super::{
     Renderer, check_layers, cull, describe_adapter, is_software, oit, startup_step, surface_format,
     timing,
 };
+// Ray tracing on request, which the device needs from its creation (gfx.rs may not grow).
+#[path = "ray_query.rs"]
+mod ray_query;
 use std::sync::Arc;
 use winit::window::Window;
 
@@ -134,6 +137,7 @@ pub(super) async fn open_adapter(
     let features = timing::GpuTimer::features(adapter)
         | cull::Cull::features(adapter)
         | oit::features(adapter)
+        | ray_query::features(adapter)
         | (adapter.features()
             & (wgpu::Features::INDIRECT_FIRST_INSTANCE
                 | wgpu::Features::MULTI_DRAW_INDIRECT_COUNT
@@ -166,6 +170,7 @@ pub(super) async fn open_adapter(
         // with the larger blocks a few small buffers kept whole blocks the arena's pages had
         // left, and over half the video memory reserved was unused (1,344 MiB for 500).
         memory_hints: wgpu::MemoryHints::MemoryUsage,
+        experimental_features: ray_query::experimental(features),
         ..Default::default()
     };
     #[cfg(not(target_os = "macos"))]

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

@@ -2,16 +2,21 @@
 //! colours and the controls it draws with. The screen (`graphics_ui`) only
 //! lays out rows and handles input; a menu theme replaces this module.
 //!
-//! It takes the design system's Blocks palette (`horizon_theme::BLOCKS_DARK`,
-//! `docs/design-system.md`) in a lighter form: square panels of dark glass
-//! with a thin edge, so the world shows through, flat controls, and the violet
-//! face on the one main button, in vanilla's font.
+//! Its colours come from `menu_style`, given at startup (in the official game the design
+//! system's Blocks palette, `docs/design-system.md`), in a lighter form: square panels of
+//! dark glass with a thin edge, so the world shows through, flat controls, and the face on
+//! the one main button, in vanilla's font.
+use crate::menu_style::{self, SettingsColours};
 use crate::{
     hud::{HudAtlas, HudBatch},
     text::Text,
     ui,
 };
-use horizon_theme::BLOCKS_DARK as B;
+
+/// The settings pages' colours (`menu_style`, given at startup).
+fn b() -> &'static SettingsColours {
+    &menu_style::get().settings
+}
 
 /// What a setting costs in frame time, shown with its description.
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
@@ -36,54 +41,91 @@ impl Cost {
     /// `0xRRGGBB`: the palette's success, warn and danger.
     pub fn rgb(self) -> u32 {
         match self {
-            Cost::None => B.ink_soft,
-            Cost::Low | Cost::Saves => B.success,
-            Cost::Medium => B.warn,
-            Cost::High => B.danger,
+            Cost::None => b().ink_soft,
+            Cost::Low | Cost::Saves => b().success,
+            Cost::Medium => b().warn,
+            Cost::High => b().danger,
         }
     }
 }
 
-/// `0xRRGGBB` and an alpha in the HUD's colour encoding.
-const fn hex(c: u32, a: u8) -> u32 {
-    (a as u32) << 24 | (c & 0xff) << 16 | (c >> 8 & 0xff) << 8 | (c >> 16 & 0xff)
-}
+use menu_style::hud_colour as hex;
 /// The plate and the strip: the page's dark, see-through, so the world shows behind them.
-const GLASS: u32 = hex(B.page, 118);
+fn glass() -> u32 {
+    hex(b().page, 118)
+}
 /// Their 1 px edge.
-const EDGE: u32 = hex(B.ink, 26);
+pub fn edge() -> u32 {
+    hex(b().ink, 26)
+}
 /// A group's panel, a little lighter than the plate it sits on.
-const GROUP: u32 = hex(B.ink, 11);
+fn group_fill() -> u32 {
+    hex(b().ink, 11)
+}
 /// A hovered or focused row, lit on its group's panel.
-pub const HOVER: u32 = hex(B.ink, 18);
+pub fn hover() -> u32 {
+    hex(b().ink, 18)
+}
 /// The open page in the page list.
-pub const OPEN: u32 = hex(B.ink, 26);
+pub fn open() -> u32 {
+    hex(b().ink, 26)
+}
 /// The rule under the plate's heading, and between two rows of a group.
-pub const HEAD_RULE: u32 = hex(B.ink, 31);
-pub const ROW_RULE: u32 = hex(B.ink, 15);
+pub fn head_rule() -> u32 {
+    hex(b().ink, 31)
+}
+pub fn row_rule() -> u32 {
+    hex(b().ink, 15)
+}
 /// Fields, boxes and the value stepper: sunk, see-through.
-const WELL: u32 = hex(B.outline, 102);
+fn well_fill() -> u32 {
+    hex(b().outline, 102)
+}
 /// A button, a slider's track, the scroller's thumb.
-const BUTTON: u32 = hex(B.ink, 20);
-const BUTTON_HOVER: u32 = hex(B.ink, 41);
-const TRACK: u32 = hex(B.ink, 64);
-const HANDLE: u32 = hex(B.ink, 255);
+fn button_fill() -> u32 {
+    hex(b().ink, 20)
+}
+fn button_hover() -> u32 {
+    hex(b().ink, 41)
+}
+fn track_fill() -> u32 {
+    hex(b().ink, 64)
+}
+fn handle_fill() -> u32 {
+    hex(b().ink, 255)
+}
 /// The one main button.
-const FACE: u32 = hex(B.face, 255);
-const FACE_HOVER: u32 = hex(0x6a50e6, 255);
+pub fn face() -> u32 {
+    hex(b().face, 255)
+}
+fn face_hover() -> u32 {
+    hex(b().face_hover, 255)
+}
 /// A tick box's edge when off.
-const BOX_EDGE: u32 = hex(B.ink_soft, 89);
-const OUTLINE: u32 = hex(B.outline, 255);
-pub const ACCENT: u32 = hex(B.accent, 255);
+fn box_edge() -> u32 {
+    hex(b().ink_soft, 89)
+}
+fn outline() -> u32 {
+    hex(b().outline, 255)
+}
+pub fn accent() -> u32 {
+    hex(b().accent, 255)
+}
 /// Vanilla's white text, and its grey for what can't be used now.
 pub const WHITE: u32 = u32::MAX;
-pub const MUTED: u32 = hex(B.muted, 255);
+pub fn muted() -> u32 {
+    hex(b().muted, 255)
+}
 /// A page that isn't open, a value at rest.
-pub const SOFT: u32 = hex(B.ink_soft, 255);
+pub fn soft() -> u32 {
+    hex(b().ink_soft, 255)
+}
 /// Vanilla's grey for a tooltip's lines under its first (`ChatFormatting.GRAY`).
 pub const GREY: u32 = hex(0xaaaaaa, 255);
 /// A light veil over the backdrop, under the panels.
-pub const VEIL: u32 = hex(B.page, 77);
+pub fn veil() -> u32 {
+    hex(b().page, 77)
+}
 
 /// Sizes in GUI pixels.
 /// Shorter screens than this (a 720p window at scale 3) keep a narrower margin on top.
@@ -120,21 +162,21 @@ pub fn ring(batch: &mut HudBatch, atlas: &HudAtlas, [x, y, w, h]: [f32; 4], colo
 }
 /// The screen's plate, and the strip under it: dark glass with a thin edge.
 pub fn panel(batch: &mut HudBatch, atlas: &HudAtlas, rect: [f32; 4]) {
-    fill(batch, atlas, rect, GLASS);
-    ring(batch, atlas, rect, EDGE);
+    fill(batch, atlas, rect, glass());
+    ring(batch, atlas, rect, edge());
 }
 /// A group's panel on the plate, its rows on it.
 pub fn group(batch: &mut HudBatch, atlas: &HudAtlas, rect: [f32; 4]) {
-    fill(batch, atlas, rect, GROUP);
+    fill(batch, atlas, rect, group_fill());
 }
 /// A sunk well: the search field, the value stepper.
 pub fn well(batch: &mut HudBatch, atlas: &HudAtlas, rect: [f32; 4]) {
-    fill(batch, atlas, rect, WELL);
+    fill(batch, atlas, rect, well_fill());
 }
 /// The scroller: a faint track and its thumb.
 pub fn scroller(batch: &mut HudBatch, atlas: &HudAtlas, track: [f32; 4], thumb: [f32; 4]) {
-    fill(batch, atlas, track, ROW_RULE);
-    fill(batch, atlas, thumb, TRACK);
+    fill(batch, atlas, track, row_rule());
+    fill(batch, atlas, thumb, track_fill());
 }
 /// `text` cut to `width` with an ellipsis, as a long name gives way to its control: the HUD
 /// kit's `fit::ellipsize`.
@@ -142,11 +184,11 @@ pub use crate::hud_kit::fit::ellipsize as fit;
 /// A 12 px tick box ending at `right`, centred in the row at `y`: its edge in the accent when on.
 pub fn checkbox(batch: &mut HudBatch, atlas: &HudAtlas, right: f32, y: f32, on: bool, live: bool) {
     let rect = [right - 12.0, y + 4.0, 12.0, 12.0];
-    fill(batch, atlas, rect, WELL);
+    fill(batch, atlas, rect, well_fill());
     let edge = match (on, live) {
-        (true, true) => ACCENT,
-        (true, false) => MUTED,
-        (false, _) => BOX_EDGE,
+        (true, true) => accent(),
+        (true, false) => muted(),
+        (false, _) => box_edge(),
     };
     ring(batch, atlas, rect, edge);
     if on {
@@ -169,7 +211,7 @@ fn tick(batch: &mut HudBatch, atlas: &HudAtlas, x: f32, y: f32, color: u32) {
         for (i, c) in row.chars().enumerate() {
             if c == '#' {
                 let (px, py) = (x + i as f32, y + j as f32);
-                fill(batch, atlas, [px + 1.0, py + 1.0, 1.0, 1.0], OUTLINE);
+                fill(batch, atlas, [px + 1.0, py + 1.0, 1.0, 1.0], outline());
                 fill(batch, atlas, [px, py, 1.0, 1.0], color);
             }
         }
@@ -198,17 +240,17 @@ pub fn button_with_room(
 ) {
     let [x, y, w, h] = rect;
     let face = match (live, primary, hover) {
-        (false, _, _) => WELL,
-        (true, true, false) => FACE,
-        (true, true, true) => FACE_HOVER,
-        (true, false, false) => BUTTON,
-        (true, false, true) => BUTTON_HOVER,
+        (false, _, _) => well_fill(),
+        (true, true, false) => face(),
+        (true, true, true) => face_hover(),
+        (true, false, false) => button_fill(),
+        (true, false, true) => button_hover(),
     };
     fill(batch, atlas, rect, face);
     if hover && live {
         ring(batch, atlas, rect, WHITE);
     }
-    let color = if live { WHITE } else { MUTED };
+    let color = if live { WHITE } else { muted() };
     let ty = y + ((h - 8.0) / 2.0).floor();
     let left = x + 2.0 + room;
     scrolling_label(
@@ -252,7 +294,7 @@ pub fn slider(
     (hover, live): (bool, bool),
 ) {
     let [x, y, w, h] = rect;
-    let color = if live { WHITE } else { MUTED };
+    let color = if live { WHITE } else { muted() };
     scrolling_label(
         batch,
         atlas,
@@ -263,17 +305,22 @@ pub fn slider(
     );
     let line = y + h - 3.0;
     let at = x + (position.clamp(0.0, 1.0) * (w - 4.0)).round();
-    fill(batch, atlas, [x, line, w, 2.0], TRACK);
+    fill(batch, atlas, [x, line, w, 2.0], track_fill());
     fill(
         batch,
         atlas,
         [x, line, at - x, 2.0],
-        if live { ACCENT } else { MUTED },
+        if live { accent() } else { muted() },
     );
     let handle = [at, line - 3.0, 4.0, 8.0];
-    fill(batch, atlas, handle, if live { HANDLE } else { MUTED });
+    fill(
+        batch,
+        atlas,
+        handle,
+        if live { handle_fill() } else { muted() },
+    );
     if hover && live {
-        ring(batch, atlas, [at - 1.0, line - 4.0, 6.0, 10.0], ACCENT);
+        ring(batch, atlas, [at - 1.0, line - 4.0, 6.0, 10.0], accent());
     }
 }
 /// A value that a press steps through: in a well, between the arrows that say so.
@@ -290,13 +337,13 @@ pub fn cycler(
         ring(batch, atlas, rect, WHITE);
     }
     let ty = y + ((h - 8.0) / 2.0).floor();
-    let arrows = if hover && live { WHITE } else { MUTED };
+    let arrows = if hover && live { WHITE } else { muted() };
     batch.text_styled(atlas, &Text::literal("<"), x + 3.0, ty, arrows, true);
     batch.text_styled(atlas, &Text::literal(">"), x + w - 8.0, ty, arrows, true);
     let color = match (live, hover) {
-        (false, _) => MUTED,
+        (false, _) => muted(),
         (true, true) => WHITE,
-        (true, false) => SOFT,
+        (true, false) => soft(),
     };
     scrolling_label(batch, atlas, value, [x + 9.0, ty, w - 18.0], (y, h), color);
 }

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

@@ -1110,7 +1110,8 @@ impl Item {
     /// active; saved values wait for it. Translucent Batching switches where the device can batch
     /// (`graphics::translucent_batching_offered`), its saved value waiting for one that can,
     /// Smooth Gradients only where it can draw the 16-bit frame, the same way, and GPU Culling
-    /// only where it is offered (`graphics::gpu_culling_offer`), with the reason it isn't.
+    /// only where it is offered (`graphics::gpu_culling_offer`), with the reason it isn't. HDR
+    /// Lighting has nothing to switch where the running shader pack lights the world itself.
     fn blocked(self, s: &Settings, out: &EffectiveOutput) -> Option<&'static str> {
         if !self.available() {
             return Some("This feature is not yet available in Horizon.");
@@ -1141,6 +1142,9 @@ impl Item {
             } else {
                 "Turn HDR on to use it."
             }),
+            Item::Horizon(H::HdrLighting) if out.pack_lights => {
+                Some("The shader pack lights the world itself.")
+            }
             Item::Horizon(H::TranslucentBatching)
                 if !crate::graphics::translucent_batching_offered() =>
             {

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

@@ -31,6 +31,49 @@ fn smooth_gradients_wait_for_a_device_that_draws_the_16_bit_frame() {
     assert_eq!(item.blocked(&s, &out), Some("Turn HDR on to use it."));
 }
 
+#[test]
+fn hdr_lighting_is_greyed_only_where_the_running_pack_lights_the_world() {
+    use horizon_shader_api::Api;
+    let mut s = Settings::default();
+    s.horizon.hdr = HdrMode::On;
+    let item = Item::Horizon(H::HdrLighting);
+    let lights = Some("The shader pack lights the world itself.");
+    let out = offering(true, None);
+    // No pack running, as with one picked but refused, missing or its mod off: live.
+    assert_eq!(item.blocked(&s, &out.with_pack(false, None)), None);
+    // A 0.1 pack on the 16-bit frame: the light sources and the sun still shine.
+    assert_eq!(
+        item.blocked(&s, &out.with_pack(false, Some(Api::V0_1))),
+        None
+    );
+    assert_eq!(
+        item.blocked(&s, &out.with_pack(false, Some(Api::V0_2))),
+        lights
+    );
+    assert_eq!(item.blocked(&s, &out.with_pack(true, None)), lights);
+    let float = EffectiveOutput {
+        frame: crate::gfx::FrameConfiguration {
+            format: wgpu::TextureFormat::Rgba16Float,
+            ..out.frame
+        },
+        ..out
+    };
+    assert_eq!(
+        item.blocked(&s, &float.with_pack(false, Some(Api::V0_1))),
+        lights
+    );
+    // HDR's own reasons come first.
+    assert_eq!(
+        item.blocked(&s, &NONE.with_pack(true, None)),
+        Some("Your display or system doesn't offer HDR output.")
+    );
+    s.horizon.hdr = HdrMode::Off;
+    assert_eq!(
+        item.blocked(&s, &out.with_pack(true, None)),
+        Some("Turn HDR on to use it.")
+    );
+}
+
 #[test]
 fn hdr_auto_can_be_selected_before_querying_and_brightness_waits_for_output() {
     let mut s = Settings::default();

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

@@ -111,11 +111,11 @@ pub struct HudAtlas {
     /// The packs' Polytone screen sprite modifiers.
     pub sprite_modifiers: std::sync::Arc<sprite_modifiers::SpriteModifiers>,
     /// The packs' OptiFine random entity textures, whose variants this atlas packs.
-    pub random_textures: horizon_optifine::random_textures::RandomTextures,
+    pub random_textures: crate::entity_textures::RandomTextures,
     /// Their emissive overlays (`_e`), packed here too.
-    pub emissive: std::sync::Arc<horizon_optifine::emissive::Emissive>,
+    pub emissive: std::sync::Arc<crate::entity_textures::Emissive>,
     /// ETF's blinking frames (`_blink`), packed here too.
-    pub blinks: horizon_optifine::blink::Blinks,
+    pub blinks: crate::entity_textures::Blinks,
     /// Of the shared atlas's textures, their LabPBR normal and specular maps as paged maps
     /// (`paged_maps.rs`), read while loading for shader packs (`sprites::labpbr_maps`).
     pub material_maps: std::sync::Arc<[Option<crate::paged_maps::PagedMap>; 2]>,
@@ -433,7 +433,7 @@ fn cit_sprites(
     packed: &[PackedImage],
 ) -> Vec<(PackedImage, Option<TextureFlags>, bool)> {
     let have: HashSet<&str> = packed.iter().map(|i| i.0.as_str()).collect();
-    let rules = crate::cit::load_rules(root);
+    let rules = crate::cit::CitRules::load(root).rules;
     let mut ids = crate::cit_assets::item_sprites(&rules);
     if !rules.is_empty() {
         let models = crate::cit_assets::load_models(root, &rules);
@@ -1204,25 +1204,18 @@ impl HudAtlas {
             let s = p.to_string_lossy().replace('\\', "/");
             !s.contains("title/background") && !s.contains("presets")
         });
-        // OptiFine random entity variants, under the names their scan gives them (those
-        // outside `textures/` are `<ns>:optifine/random/...`).
-        let random_textures = if folders.contains(&"entity") {
-            horizon_optifine::random_textures::RandomTextures::scan(root)
+        // Random entity variants, under the names their scan gives them (those outside
+        // `textures/` are `<ns>:optifine/random/...`), blink frames and emissive overlays.
+        let crate::entity_textures::EntityTextures {
+            random: random_textures,
+            blinks,
+            emissive,
+        } = if folders.contains(&"entity") {
+            crate::entity_textures::EntityTextures::load(root)
         } else {
             Default::default()
         };
-        let blinks = if folders.contains(&"entity") {
-            horizon_optifine::blink::Blinks::scan(root, &random_textures)
-        } else {
-            Default::default()
-        };
-        let emissive = std::sync::Arc::new(if folders.contains(&"entity") {
-            let mut e = horizon_optifine::emissive::Emissive::scan(root, &random_textures);
-            e.pair_beside(root, blinks.files());
-            e
-        } else {
-            Default::default()
-        });
+        let emissive = std::sync::Arc::new(emissive);
         let mut named: HashMap<PathBuf, String> = HashMap::new();
         let extra = random_textures
             .files()
@@ -3474,6 +3467,7 @@ mod tests {
     /// `RandomTextures` gives them; one beside its texture packs once, under its own.
     #[test]
     fn random_entity_variants_pack_under_their_scan_names() {
+        crate::pack_formats::install();
         let root =
             std::env::temp_dir().join(format!("horizon-atlas-random-{}", std::process::id()));
         let _ = fs::remove_dir_all(&root);
@@ -3496,6 +3490,7 @@ mod tests {
     /// A random variant's emissive overlay packs beside the variant, under its name.
     #[test]
     fn variant_overlays_pack_under_their_names() {
+        crate::pack_formats::install();
         let root =
             std::env::temp_dir().join(format!("horizon-atlas-overlay-{}", std::process::id()));
         let _ = fs::remove_dir_all(&root);
@@ -3810,6 +3805,7 @@ mod tests {
     }
     /// A resource root with one plain item texture and these CIT files (relative path, contents).
     fn cit_root(name: &str, files: &[(&str, &str)]) -> PathBuf {
+        crate::pack_formats::install();
         let root =
             std::env::temp_dir().join(format!("horizon-atlas-cit-{name}-{}", std::process::id()));
         let _ = fs::remove_dir_all(&root);
@@ -3899,7 +3895,7 @@ mod tests {
         );
         let cit = root.join("assets/minecraft/optifine/cit");
         write_strip(&cit.join("a.png"), 64, 32, &[[1, 2, 3, 255]], None);
-        let rules = crate::cit::load_rules(&root);
+        let rules = crate::cit::CitRules::load(&root).rules;
         assert_eq!(rules.len(), 1);
         let atlas = HudAtlas::build(&root).unwrap();
         let _ = fs::remove_dir_all(&root);

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

@@ -1,12 +1,12 @@
-//! OptiFine CIT enchantment glints on GUI items (`type=enchantment`, see `crate::cit_glint` for
+//! Custom item texture enchantment glints on GUI items (`Kind::Enchantment`, see `crate::cit_glint` for
 //! which layers a stack draws): every rule's texture in one texture array, each layer an extra
 //! pass over the item's quads with its rule's blend. A layer's vertices carry its texture slot
 //! (red) and its intensity (alpha) in their colour; its scrolled UV is worked out on the CPU, as
 //! vanilla's glint's is. Without enchantment rules nothing here is made.
 
 use super::HudVertex;
+use crate::cit::{Blend, Factor, Kind, Rule};
 use crate::gfx::hud_coverage::Pipeline;
-use horizon_optifine::cit::{Blend, Factor, Kind, Rule};
 use std::path::Path;
 
 /// Slots the shader's table holds; rules past it draw no layer (and match no stack).
@@ -438,13 +438,11 @@ impl CitGlintPass {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use horizon_optifine::Properties;
-    use horizon_optifine::cit::parse_blend;
+    use crate::pack_formats::cit::{parse_blend, parse_rule};
 
     fn rule(name: &str, text: &str) -> Rule {
         let path = format!("assets/minecraft/optifine/cit/{name}.properties");
-        let text = format!("texture=glint\n{text}");
-        Rule::parse(&path, &Properties::parse_equals_first(&text), |_| true).unwrap()
+        parse_rule(&path, &format!("texture=glint\n{text}")).unwrap()
     }
 
     #[test]

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

@@ -338,7 +338,7 @@ fn coverage_preserves_each_cit_blend_and_its_destination_alpha() {
     let Some(mut gpu) = Gpu::new() else {
         return;
     };
-    use horizon_optifine::cit::parse_blend;
+    use crate::pack_formats::cit::parse_blend;
     for (name, expected) in [
         ("alpha", 128),
         ("add", 0),

crates/horizon-client-render/src/hud_kit/motion.rs

@@ -3,8 +3,9 @@
 //! where a tween is at the frame's [`Clock`]; nothing here holds state or runs on its own, and
 //! no motion ever decides what input does.
 //!
-//! The curves are the design system's (`horizon_theme::QUICK`, `MOVE`): a [`Tween`] takes one
-//! of them, at the theme's duration or a shorter one of its own.
+//! A [`Tween`] takes a duration and a CSS `cubic-bezier` curve: Horizon's overlays use the design
+//! system's (`horizon_theme::QUICK`, `MOVE`), at the theme's duration or a shorter one of their
+//! own.
 //!
 //! The game builds the clock once a frame (`Clock::new(now, still)`). A still clock (the game is
 //! paused, frame-stepped by `HORIZON_STILL` or a screenshot sequence, or a repro recording or
@@ -16,7 +17,7 @@
 //! use std::time::{Duration, Instant};
 //!
 //! let opened = Instant::now();
-//! let open = Tween::new(Duration::from_millis(90), horizon_theme::QUICK);
+//! let open = Tween::new(Duration::from_millis(90), [0.4, 0.0, 0.2, 1.0]);
 //! // Half way through: partly faded in, partly grown from 94%.
 //! let clock = Clock::new(opened + Duration::from_millis(45), false);
 //! let alpha = motion::fade(open, clock, opened);
@@ -26,7 +27,6 @@
 //! let still = Clock::new(opened, true);
 //! assert_eq!(motion::fade(open, still, opened), 1.0);
 //! ```
-use horizon_theme::Motion;
 use std::time::{Duration, Instant};
 
 /// The time a frame shows, built once a frame by the game.
@@ -50,28 +50,20 @@ impl Clock {
     }
 }
 
-/// A duration and one of the design system's easing curves.
+/// A duration and an easing curve.
 #[derive(Clone, Copy, Debug, PartialEq)]
 pub struct Tween {
     /// How long it runs.
     pub duration: Duration,
-    /// The CSS `cubic-bezier` control points of its curve (a `horizon_theme::Motion`'s).
+    /// The CSS `cubic-bezier` control points of its curve.
     pub curve: [f32; 4],
 }
 
 impl Tween {
-    /// `motion`'s curve over `duration`: the dial's motions are shorter than the launcher's, on
-    /// the same curves.
-    pub const fn new(duration: Duration, motion: Motion) -> Self {
-        Self {
-            duration,
-            curve: motion.curve,
-        }
-    }
-
-    /// A theme motion as it is: its own duration and curve.
-    pub const fn of(motion: Motion) -> Self {
-        Self::new(motion.duration(), motion)
+    /// `curve` over `duration`: the dial's motions are shorter than the launcher's, on the same
+    /// curves.
+    pub const fn new(duration: Duration, curve: [f32; 4]) -> Self {
+        Self { duration, curve }
     }
 
     /// The linear progress, 0 to 1, `since` a start at this clock; 1 on a still clock.
@@ -84,7 +76,7 @@ impl Tween {
 
     /// The eased progress, 0 to 1, on the tween's curve.
     pub fn progress(self, clock: Clock, since: Instant) -> f32 {
-        horizon_theme::bezier(self.curve, self.linear(clock, since))
+        bezier(self.curve, self.linear(clock, since))
     }
 
     /// Whether it has finished (always, on a still clock).
@@ -98,6 +90,29 @@ impl Tween {
     }
 }
 
+/// A CSS `cubic-bezier(x1, y1, x2, y2)` at `t` in 0..1: solves x for the curve parameter,
+/// returns y.
+pub fn bezier([x1, y1, x2, y2]: [f32; 4], t: f32) -> f32 {
+    let t = t.clamp(0.0, 1.0);
+    if t == 0.0 || t == 1.0 {
+        return t;
+    }
+    let at = |a: f32, b: f32, s: f32| {
+        let u = 1.0 - s;
+        3.0 * u * u * s * a + 3.0 * u * s * s * b + s * s * s
+    };
+    let (mut lo, mut hi) = (0f32, 1f32);
+    for _ in 0..24 {
+        let mid = (lo + hi) / 2.0;
+        if at(x1, x2, mid) < t {
+            lo = mid;
+        } else {
+            hi = mid;
+        }
+    }
+    at(y1, y2, (lo + hi) / 2.0)
+}
+
 /// An alpha from 0 to 1 as something fades in.
 pub fn fade(tween: Tween, clock: Clock, since: Instant) -> f32 {
     tween.progress(clock, since)
@@ -145,7 +160,7 @@ mod tests {
     #[test]
     fn a_tween_runs_from_its_start_to_its_end_and_holds() {
         let t0 = Instant::now();
-        let tween = Tween::new(MS(80), horizon_theme::MOVE);
+        let tween = Tween::new(MS(80), horizon_theme::MOVE.curve);
         assert_eq!(tween.progress(at(t0, 0), t0), 0.0);
         assert_eq!(tween.progress(at(t0, 80), t0), 1.0);
         assert_eq!(tween.progress(at(t0, 500), t0), 1.0);
@@ -160,8 +175,7 @@ mod tests {
     fn a_still_clock_shows_every_motion_settled() {
         let t0 = Instant::now();
         let still = Clock::new(t0, true);
-        let tween = Tween::of(horizon_theme::QUICK);
-        assert_eq!(tween.duration, horizon_theme::QUICK.duration());
+        let tween = Tween::new(horizon_theme::QUICK.duration(), horizon_theme::QUICK.curve);
         assert_eq!(fade(tween, still, t0), 1.0);
         assert_eq!(fade_out(tween, still, t0), 0.0);
         assert_eq!(scale_in(tween, still, t0, 0.94), 1.0);
@@ -173,7 +187,7 @@ mod tests {
     #[test]
     fn the_helpers_start_where_they_say() {
         let t0 = Instant::now();
-        let tween = Tween::new(MS(100), horizon_theme::QUICK);
+        let tween = Tween::new(MS(100), horizon_theme::QUICK.curve);
         let c = at(t0, 0);
         assert_eq!(fade(tween, c, t0), 0.0);
         assert_eq!(fade_out(tween, c, t0), 1.0);
@@ -184,10 +198,25 @@ mod tests {
         assert!((flash(tween, at(t0, 25), t0) - 0.75).abs() < 1e-6);
     }
 
+    #[test]
+    fn the_curve_is_the_design_systems() {
+        for motion in horizon_theme::MOTION {
+            for i in 0..=20 {
+                let t = i as f32 / 20.0;
+                assert_eq!(
+                    bezier(motion.curve, t),
+                    motion.ease(t),
+                    "{} at {t}",
+                    motion.name
+                );
+            }
+        }
+    }
+
     #[test]
     fn a_turn_takes_the_short_way_round() {
         let t0 = Instant::now();
-        let tween = Tween::new(MS(80), horizon_theme::MOVE);
+        let tween = Tween::new(MS(80), horizon_theme::MOVE.curve);
         // From up-left (7/8 of a turn) to up-right: through up, not round the bottom.
         let from = 7.0 * FRAC_PI_4;
         let half = turn(tween, at(t0, 1), t0, from, FRAC_PI_4);

crates/horizon-client-render/src/hud_kit/tabs.rs

@@ -38,6 +38,12 @@
 //! ```
 use crate::hud::{HudAtlas, HudBatch};
 use crate::hud_kit::{colour, fit};
+use crate::menu_style::{self, OverlayColours};
+
+/// The overlays' colours (`menu_style`, given at startup).
+fn overlay() -> &'static OverlayColours {
+    &menu_style::get().overlay
+}
 
 /// A pip under the strip: its size and the step from one to the next, in GUI px.
 pub const PIP: [f32; 2] = [3.0, 2.0];
@@ -45,8 +51,12 @@ pub const PIP_STEP: f32 = 5.0;
 /// How far, in GUI px, the arrows sit from the name.
 pub const ARROW_GAP: f32 = 4.0;
 /// An arrow with a page that way, and one at an end, with none.
-pub const ARROW: u32 = colour(horizon_theme::BACKDROP_MUTED, 255);
-pub const ARROW_OFF: u32 = colour(horizon_theme::BACKDROP_MUTED, 77);
+pub fn arrow_colour() -> u32 {
+    colour(overlay().backdrop_muted, 255)
+}
+pub fn arrow_off_colour() -> u32 {
+    colour(overlay().backdrop_muted, 77)
+}
 /// The pips (the selected one is white).
 pub const PIP_OFF: u32 = colour(0xFFFFFF, 89);
 pub const PIP_ON: u32 = colour(0xFFFFFF, 255);
@@ -65,9 +75,15 @@ pub const EDGE_FADE: f32 = 12.0;
 pub const FADE: [f32; 5] = [1.0, 0.7, 0.35, 0.15, 0.1];
 /// The selected tab's fill and text, and the others'.
 pub const SELECTED_FILL: u32 = colour(0xFFFFFF, 242);
-pub const SELECTED_TEXT: u32 = colour(horizon_theme::DARK.page, 255);
-pub const TAB_FILL: u32 = colour(horizon_theme::DARK.page, 191);
-pub const TAB_TEXT: u32 = colour(horizon_theme::BACKDROP_MUTED, 255);
+pub fn selected_text() -> u32 {
+    colour(overlay().page, 255)
+}
+pub fn tab_fill() -> u32 {
+    colour(overlay().page, 191)
+}
+pub fn tab_text() -> u32 {
+    colour(overlay().backdrop_muted, 255)
+}
 /// The line of text's height in GUI px (vanilla's font, without its shadow).
 const LINE: f32 = 8.0;
 
@@ -144,7 +160,11 @@ pub fn draw(batch: &mut HudBatch, atlas: &HudAtlas, strip: &Strip) {
             arrow,
             ax,
             ay,
-            if on { ARROW } else { ARROW_OFF },
+            if on {
+                arrow_colour()
+            } else {
+                arrow_off_colour()
+            },
             true,
         );
     }
@@ -282,9 +302,9 @@ pub fn draw_tabs(batch: &mut HudBatch, atlas: &HudAtlas, strip: &TabStrip, alpha
     for tab in &row.tabs {
         let [tx, ty, tw, th] = tab.area;
         let (fill, text) = if tab.selected {
-            (SELECTED_FILL, SELECTED_TEXT)
+            (SELECTED_FILL, selected_text())
         } else {
-            (TAB_FILL, TAB_TEXT)
+            (tab_fill(), tab_text())
         };
         let tab_start = batch.vertices.len();
         // Cut where the edges' fades start, so each fade runs over its own piece.
@@ -380,15 +400,16 @@ mod tests {
             let [ax, _] = strip.arrows[i];
             (batch.vertices.iter())
                 .filter(|v| {
-                    (v.pos[0] - ax).abs() < 4.0 && v.color & 0x00FF_FFFF == ARROW & 0x00FF_FFFF
+                    (v.pos[0] - ax).abs() < 4.0
+                        && v.color & 0x00FF_FFFF == arrow_colour() & 0x00FF_FFFF
                 })
                 .map(|v| v.color >> 24)
                 .max()
                 .unwrap_or(0)
         };
         let first = collapsed(&atlas, &pages, 0, AREA);
-        assert_eq!(alpha(&first, 0), ARROW_OFF >> 24);
-        assert_eq!(alpha(&first, 1), ARROW >> 24);
+        assert_eq!(alpha(&first, 0), arrow_off_colour() >> 24);
+        assert_eq!(alpha(&first, 1), arrow_colour() >> 24);
     }
 
     #[test]

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

@@ -14,7 +14,6 @@ pub mod biome;
 pub mod block_edit;
 pub mod block_entities;
 pub mod block_entity_anim;
-pub mod block_entity_cem;
 pub mod block_entity_render;
 pub mod block_sprites;
 pub mod block_states;
@@ -44,6 +43,7 @@ pub mod custom_sky;
 pub mod datapack;
 pub mod dynamic_light;
 pub mod effects;
+pub mod entity_textures;
 pub mod environment;
 pub mod extras;
 pub(crate) mod extras_ui;
@@ -51,7 +51,6 @@ pub mod fast_hash;
 pub mod fluid_render;
 pub mod fog;
 pub mod font;
-pub mod fusion;
 pub mod gfx;
 pub mod graphics;
 pub mod graphics_style;
@@ -74,6 +73,7 @@ pub mod light;
 pub mod lod;
 pub mod logging;
 pub mod menu_blur;
+pub mod menu_style;
 pub mod mesher;
 pub mod minimap;
 pub mod mipmap;

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

@@ -0,0 +1,145 @@
+//! The look of the screens vanilla doesn't have that the engine still draws: the settings pages
+//! (`graphics_style`), the HUD kit's tab strip, and the overlays drawn with `ui_theme` (the
+//! on-screen keyboard, the boot screen, the missing-resources window). Vanilla's screens never
+//! read it.
+//!
+//! The layer above gives it once at startup ([`install`]), before the first frame; the
+//! official game gives Horizon's design system (`docs/design-system.md`). With none given, the
+//! screens draw in [`NEUTRAL`]: vanilla's greys and chat colours, and no text where they would
+//! use their own fonts. A read is one atomic load, and only those screens make it.
+use std::sync::OnceLock;
+
+/// Colours as `0xRRGGBB`, sizes in dp (the launcher's logical pixels).
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub struct MenuStyle {
+    pub settings: SettingsColours,
+    pub overlay: OverlayColours,
+    pub sizes: Sizes,
+    /// The overlays' TrueType faces; none: they draw no text.
+    pub fonts: Option<Fonts>,
+}
+
+/// The settings pages: square panels of dark glass over the world, flat controls, one face.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub struct SettingsColours {
+    /// The plate behind everything, drawn see-through.
+    pub page: u32,
+    /// Text, and the light the panels, rules, hovers and controls are drawn in.
+    pub ink: u32,
+    /// Secondary text and values.
+    pub ink_soft: u32,
+    /// Labels, descriptions, what can't be used.
+    pub muted: u32,
+    /// Wells and the dark edge of small marks.
+    pub outline: u32,
+    /// Focus, a checked box, a slider's fill.
+    pub accent: u32,
+    /// The one main button, and while hovered.
+    pub face: u32,
+    pub face_hover: u32,
+    pub success: u32,
+    pub warn: u32,
+    pub danger: u32,
+}
+
+/// Overlays drawn over the game (the HUD kit's tab strip, `ui_theme`'s overlays).
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub struct OverlayColours {
+    /// The dark page under text and tabs.
+    pub page: u32,
+    /// Muted text over a veiled backdrop.
+    pub backdrop_muted: u32,
+    /// Text and the light hover and pressed plates are drawn in.
+    pub ink: u32,
+    /// Secondary text and values.
+    pub ink_soft: u32,
+    /// One-pixel rules between rows.
+    pub rule: u32,
+    /// The main action, and its text.
+    pub accent: u32,
+    pub on_accent: u32,
+}
+
+/// `ui_theme`'s type scale and shapes, in dp.
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub struct Sizes {
+    pub caption: f32,
+    pub label: f32,
+    pub ui: f32,
+    pub body: f32,
+    pub title: f32,
+    /// The boot screen's wordmark at its smallest, and its console lines.
+    pub display: f32,
+    pub micro: f32,
+    /// Fields; plates (hover rows, selection); a large control's height.
+    pub radius: f32,
+    pub radius_plate: f32,
+    pub control_large: f32,
+}
+
+/// TrueType faces (`ui_theme::Face`).
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub struct Fonts {
+    pub regular: &'static [u8],
+    pub medium: &'static [u8],
+    pub semibold: &'static [u8],
+    pub mono: &'static [u8],
+}
+
+/// The look with nothing given: vanilla's greys and chat colours.
+pub const NEUTRAL: MenuStyle = MenuStyle {
+    settings: SettingsColours {
+        page: 0x101010,
+        ink: 0xffffff,
+        ink_soft: 0xe0e0e0,
+        muted: 0xa0a0a0,
+        outline: 0x000000,
+        accent: 0xffffff,
+        face: 0x555555,
+        face_hover: 0x6f6f6f,
+        success: 0x55ff55,
+        warn: 0xffff55,
+        danger: 0xff5555,
+    },
+    overlay: OverlayColours {
+        page: 0x101010,
+        backdrop_muted: 0xa0a0a0,
+        ink: 0xffffff,
+        ink_soft: 0xe0e0e0,
+        rule: 0x303030,
+        accent: 0xffffff,
+        on_accent: 0x000000,
+    },
+    sizes: Sizes {
+        caption: 12.0,
+        label: 13.0,
+        ui: 14.0,
+        body: 15.0,
+        title: 28.0,
+        display: 44.0,
+        micro: 11.0,
+        radius: 0.0,
+        radius_plate: 0.0,
+        control_large: 40.0,
+    },
+    fonts: None,
+};
+
+static STYLE: OnceLock<MenuStyle> = OnceLock::new();
+
+/// Give the menus their look: call it once at startup. A second call keeps the first look and
+/// returns false.
+pub fn install(style: MenuStyle) -> bool {
+    STYLE.set(style).is_ok()
+}
+
+/// The look given to [`install`], or [`NEUTRAL`].
+#[inline]
+pub fn get() -> &'static MenuStyle {
+    STYLE.get().unwrap_or(&NEUTRAL)
+}
+
+/// `0xRRGGBB` and an alpha in the HUD's colour encoding (`0xAABBGGRR`).
+pub const fn hud_colour(rgb: u32, alpha: u8) -> u32 {
+    (alpha as u32) << 24 | (rgb & 0xff) << 16 | (rgb >> 8 & 0xff) << 8 | (rgb >> 16 & 0xff)
+}

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

@@ -11,7 +11,7 @@ mod sides;
 #[cfg(test)]
 #[path = "mesher/source_tests.rs"]
 mod source_tests;
-use crate::connected::{Pick, TileLayer};
+use crate::connected::{ConnectedTextures, NoConnected, Pick, TileLayer};
 use crate::{
     assets::{Assets, RenderAssets},
     biome::{Biomes, GrassModifier},
@@ -24,7 +24,6 @@ use horizon_assets::model::Direction as ModelDirection;
 use horizon_core::{
     biome::BiomeZoom, geometry::Direction, position::BlockPos, random::position_seed,
 };
-use horizon_optifine::ctm::connect::{Axes as CtmAxes, Face as CtmFace};
 use horizon_world::{
     block_render::FaceVisibility,
     fluid::{FluidKind, FluidState},
@@ -1872,11 +1871,27 @@ impl Mesher<'_> {
         )
     }
     /// The meshing workers' path: `out`'s buffers and `scratch` are reused
-    /// rather than allocated per section.
+    /// rather than allocated per section. A pack's connected textures mesh through their
+    /// format's entry point ([`crate::connected::Connected::mesh`]).
     pub fn mesh_reusing(
         &mut self,
         region: &[[Option<&Chunk>; 3]; 3],
         sy: i32,
+        out: SectionMesh,
+        scratch: &mut MeshScratch,
+    ) -> SectionMesh {
+        let render = self.render;
+        match &render.connected {
+            Some(connected) => (connected.mesh)(self, &*connected.rules, region, sy, out, scratch),
+            None => self.mesh_with(&NoConnected, region, sy, out, scratch),
+        }
+    }
+    /// [`Self::mesh_reusing`] with the connected textures `connected`.
+    pub fn mesh_with<C: ConnectedTextures>(
+        &mut self,
+        connected: &C,
+        region: &[[Option<&Chunk>; 3]; 3],
+        sy: i32,
         mut out: SectionMesh,
         scratch: &mut MeshScratch,
     ) -> SectionMesh {
@@ -2021,7 +2036,6 @@ impl Mesher<'_> {
                                 )
                                 .unwrap_or(true);
                     }
-                    let connected = &self.render.connected;
                     let start = [out.solid.len(), out.translucent.len()];
                     for model in &models {
                         for face in &model.faces {
@@ -2052,6 +2066,7 @@ impl Mesher<'_> {
                                 }
                             }
                             self.face(
+                                connected,
                                 pad,
                                 &mut tints,
                                 &mut out,
@@ -2102,8 +2117,9 @@ impl Mesher<'_> {
         })
     }
     #[allow(clippy::too_many_arguments)]
-    fn face(
+    fn face<C: ConnectedTextures>(
         &self,
+        connected: &C,
         pad: &Padded,
         tints: &mut Tints,
         out: &mut SectionMesh,
@@ -2163,55 +2179,40 @@ impl Mesher<'_> {
             }
             None => tint,
         };
-        // Fusion's and then OptiFine's connected textures: another sprite, or one per quarter,
-        // and the overlays drawn over it (a few per face at most; more are dropped).
-        let (fusion, connected) = (&self.render.fusion, &self.render.connected);
+        // Connected textures: another sprite, or one per quarter, and the overlays drawn over it
+        // (a few per face at most; more are dropped).
         let mut overlays = [None; 8];
         let mut count = 0;
-        let mut push = |overlay| {
-            if let Some(slot) = overlays.get_mut(count) {
-                *slot = Some(overlay);
-                count += 1;
-            }
-        };
-        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,
-                id,
-                CtmFace::ALL[q.facing as usize],
-                q.tint_index,
-                neighbour,
+        let pick = if connected.is_empty() {
+            Pick::Keep
+        } else {
+            let mut push = |overlay| {
+                if let Some(slot) = overlays.get_mut(count) {
+                    *slot = Some(overlay);
+                    count += 1;
+                }
+            };
+            let tints = &*tints;
+            connected.pick(
+                &crate::connected::Face {
+                    state: id,
+                    layer: face.layer as u16,
+                    facing: q.facing as u8,
+                    pos: [world.x, world.y, world.z],
+                    positions: &q.positions,
+                    uv: &q.uv,
+                    pane: state.pane,
+                    tint_index: q.tint_index,
+                    rule: face.fusion,
+                },
+                |n: [i32; 3]| pad.blocks[(cell as isize + step_index(n)) as usize],
                 |s| {
                     self.tables
                         .info
                         .get(s as usize)
                         .is_some_and(|i| i.opaque_cube)
                 },
-                &mut push,
-            )
-        });
-        let pick = if let Some(pick) = fused {
-            pick
-        } else if connected.is_empty() {
-            Pick::Keep
-        } else {
-            let tints = &*tints;
-            connected.pick(
-                id,
-                face.layer as u16,
-                CtmFace::ALL[q.facing as usize],
-                [world.x, world.y, world.z],
-                neighbour,
                 || Some(tints.biome(pos[0], pos[1], pos[2])),
-                // A pane's tiles are drawn with the cube's UVs (below), so that is its texture.
-                || {
-                    if state.pane {
-                        Some(CtmAxes::cube(CtmFace::ALL[q.facing as usize]))
-                    } else {
-                        CtmAxes::texture(&q.positions, &q.uv)
-                    }
-                },
                 &mut push,
             )
         };

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

@@ -100,8 +100,7 @@ fn fixture() -> (Scratch, Assets, RenderAssets, MeshTables, Biomes) {
         pbr_normals: vec![],
         pbr_specular: vec![],
         pbr_size: 1,
-        connected: Default::default(),
-        fusion: Default::default(),
+        connected: None,
         generation: 1,
     };
     let assets = Assets {

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

@@ -1,6 +1,7 @@
 //! Optional, texture-matched overlays drawn full bright over their base texture in the same
-//! terrain fragment: native mods' (`<ns>:emissive/...`) and OptiFine's emissive block textures
-//! (`block/stone_e.png` beside `block/stone.png`). No extra draw calls or world light changes.
+//! terrain fragment: native mods' (`<ns>:emissive/...`) and a pack's emissive block textures
+//! (OptiFine's `block/stone_e.png` beside `block/stone.png`, the suffix from the pack formats,
+//! [`crate::pack_hooks`]). No extra draw calls or world light changes.
 use crate::sprites::Sprites;
 use std::{collections::BTreeMap, path::Path};
 
@@ -35,14 +36,12 @@ fn tile_file(name: &str) -> Option<&str> {
     name.strip_suffix(".png")
 }
 
-/// OptiFine's emissive overlays of the block sprites already loaded (what the terrain draws;
-/// items draw from the HUD atlas): for each
-/// `<ns>:block/<name>`, or connected-texture tile `assets/<ns>/.../<name>.png`, whose
-/// `<name><suffix>.png` sits beside it, the overlay is loaded too and paired with it, blocks
-/// first, then tiles, each by name, at most [`MAX`] - [`NATIVE`] (native mods keep their share of
-/// the table). A pack without such files adds nothing.
-pub fn load_optifine(root: &Path, sprites: &mut Sprites) -> Vec<(String, String)> {
-    let suffix = horizon_optifine::emissive::suffix(root);
+/// A pack's emissive overlays of the block sprites already loaded (what the terrain draws;
+/// items draw from the HUD atlas): for each `<ns>:block/<name>`, or connected-texture tile
+/// `assets/<ns>/.../<name>.png`, whose `<name><suffix>.png` sits beside it, the overlay is loaded
+/// too and paired with it, blocks first, then tiles, each by name, at most [`MAX`] - [`NATIVE`]
+/// (native mods keep their share of the table). A pack without such files adds nothing.
+pub fn load_overlays(root: &Path, suffix: &str, sprites: &mut Sprites) -> Vec<(String, String)> {
     // Blocks with identical pixels share a layer (and the shader pairs by layer): a shared
     // base would glow on every block that shares it, so it gets no overlay.
     let mut sharing: BTreeMap<u32, usize> = BTreeMap::new();
@@ -56,8 +55,8 @@ pub fn load_optifine(root: &Path, sprites: &mut Sprites) -> Vec<(String, String)
             sharing[layer] == 1
                 && (name
                     .split_once(':')
-                    .is_some_and(|(_, p)| p.starts_with("block/") && !p.ends_with(&suffix))
-                    || tile_file(name).is_some_and(|stem| !stem.ends_with(&suffix)))
+                    .is_some_and(|(_, p)| p.starts_with("block/") && !p.ends_with(suffix))
+                    || tile_file(name).is_some_and(|stem| !stem.ends_with(suffix)))
         })
         .map(|(name, _)| name.clone())
         .collect();
@@ -110,7 +109,7 @@ pub fn load_optifine(root: &Path, sprites: &mut Sprites) -> Vec<(String, String)
 pub const CUTOUT: u32 = 1 << 31;
 
 /// The frame's overlay table: native mods' pairs (at most [`NATIVE`] requested), then the packs'
-/// OptiFine pairs flagged [`CUTOUT`] (at most [`MAX`] - [`NATIVE`], as [`load_optifine`] loads),
+/// OptiFine pairs flagged [`CUTOUT`] (at most [`MAX`] - [`NATIVE`], as [`load_overlays`] loads),
 /// one per base layer with native mods' first, sorted by base layer for the shader's early exit.
 pub fn table<'a>(
     layers: &BTreeMap<String, u32>,
@@ -204,7 +203,7 @@ mod tests {
         // Items draw from the HUD atlas, not the terrain: no pair.
         sprites.insert(&root, "minecraft:item/stick").unwrap();
         // glowstone isn't loaded: its overlay pairs with nothing.
-        let pairs = load_optifine(&root, &mut sprites);
+        let pairs = load_overlays(&root, "_e", &mut sprites);
         assert_eq!(
             pairs,
             [(
@@ -215,9 +214,6 @@ mod tests {
         assert!(sprites.layers.contains_key("minecraft:block/stone_e"));
         assert!(!sprites.layers.contains_key("minecraft:block/granite_e"));
         // The pack's own suffix.
-        let props = root.join("assets/minecraft/optifine/emissive.properties");
-        std::fs::create_dir_all(props.parent().unwrap()).unwrap();
-        std::fs::write(&props, "suffix.emissive=_glow").unwrap();
         // Connected-texture tiles pair with the overlay beside them.
         let tiles = root.join("assets/minecraft/optifine/ctm/lamp");
         png(&tiles.join("0.png"), 230);
@@ -234,7 +230,7 @@ mod tests {
                 .insert_file(&root, &format!("assets/minecraft/optifine/{tile}.png"))
                 .unwrap();
         }
-        let pairs = load_optifine(&root, &mut sprites);
+        let pairs = load_overlays(&root, "_glow", &mut sprites);
         assert_eq!(
             pairs,
             // Blocks first, then tiles.

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

@@ -1501,7 +1501,7 @@ pub enum Event {
     /// ones that differ from their defaults (the others went back to theirs).
     PackOptions {
         entries: Vec<String>,
-        chosen: std::collections::BTreeMap<String, horizon_polytone::pack::ConfigValue>,
+        chosen: std::collections::BTreeMap<String, horizon_pack_options::ConfigValue>,
     },
     /// An accepted button press or the release of a slider.
     ButtonClick,
@@ -1688,7 +1688,7 @@ pub struct OptionsUi {
     /// The Pack Options page, and the packs' Polytone config entries by pack id (the game
     /// fills them beside `pack_infos`).
     pub pack_options: crate::pack_options_ui::PackOptionsUi,
-    pub pack_configs: std::collections::BTreeMap<String, horizon_polytone::pack::Configs>,
+    pub pack_configs: std::collections::BTreeMap<String, horizon_pack_options::Configs>,
     pub split_profiles: crate::split_profiles::SplitProfiles,
     /// HDR calibration while its page is open.
     pub calibration: Option<crate::hdr_calibration::Calibration>,
@@ -4018,7 +4018,7 @@ impl OptionsUi {
                     events.push(Event::DownloadPack(i));
                 }
                 crate::pack_screen::Action::Options(id) => {
-                    let mut configs = horizon_polytone::pack::Configs::default();
+                    let mut configs = horizon_pack_options::Configs::default();
                     if let Some(own) = self.pack_configs.get(&id) {
                         configs.merge(own);
                     }

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

@@ -162,10 +162,38 @@ impl OptionsUi {
         };
         let mut rows = Vec::new();
         registered.rows(&mut rows);
-        rows.into_iter()
-            .enumerate()
-            .map(|(r, row)| self.added_row(page, r, row))
-            .collect()
+        let mut out = Vec::new();
+        // The row a half-width button started, waiting for the next to sit beside it.
+        let mut half_open = false;
+        for (r, row) in rows.into_iter().enumerate() {
+            match row {
+                // Wrapped as the engine's own notes; space is for pages drawn as a screen.
+                added::Row::Text { text, .. } => {
+                    out.extend(wrap(&text, 64).into_iter().map(Row::Note))
+                }
+                added::Row::Space(_) => continue,
+                added::Row::Button {
+                    label,
+                    active,
+                    half: true,
+                    ..
+                } => {
+                    let mut half = button(0.0, 0.0, 150.0, tr(label), Act::PageRow(page, r));
+                    if !active {
+                        half = inactive(half);
+                    }
+                    match out.last_mut() {
+                        Some(Row::Buttons(_, second @ None)) if half_open => *second = Some(half),
+                        _ => out.push(Row::Buttons(half, None)),
+                    }
+                    half_open = !half_open;
+                    continue;
+                }
+                row => out.push(self.added_row(page, r, row)),
+            }
+            half_open = false;
+        }
+        out
     }
 
     fn added_row(&self, page: usize, r: usize, row: added::Row) -> Row {
@@ -177,7 +205,10 @@ impl OptionsUi {
             added::Row::Toggle { label, on } => wide(generic(label, on_off(on))),
             added::Row::Cycle { label, value } => wide(generic(label, label_text(value))),
             added::Row::Slider { .. } => Row::Big(Opt::Page(page, r)),
-            added::Row::Button { label } => wide(tr(label)),
+            added::Row::Button { label, active, .. } => {
+                let wide = button(0.0, 0.0, 310.0, tr(label), act);
+                Row::Buttons(if active { wide } else { inactive(wide) }, None)
+            }
             added::Row::Key { label, key } => {
                 let mut message = keybinds::display_name(&key);
                 if self.selected_key == Some(PAGE_KEY)
@@ -461,4 +492,84 @@ mod tests {
             Some(tr("test.sample.switch.tooltip").plain())
         );
     }
+
+    /// Text, a grey note, space, two half buttons (the second inactive) and a footer button.
+    struct Shaped(Mutex<Vec<usize>>);
+
+    impl added::Page for Shaped {
+        fn id(&self) -> &'static str {
+            "test.shaped"
+        }
+        fn title(&self) -> &'static str {
+            "test.shaped.title"
+        }
+        fn place(&self) -> added::Place {
+            added::Place::HorizonSettings
+        }
+        fn rows(&self, rows: &mut Vec<added::Row>) {
+            rows.push(added::Row::text("ABCDE-FGHIJ").groups());
+            rows.push(added::Row::text("grey").quiet());
+            rows.push(added::Row::Space(6));
+            rows.push(added::Row::button("test.shaped.copy").half());
+            rows.push(added::Row::button("test.shaped.stop").half().active(false));
+            rows.push(added::Row::button("test.shaped.help").footer());
+        }
+        fn act(&self, row: usize, _: added::Act) {
+            self.0.lock().unwrap().push(row);
+        }
+    }
+
+    static SHAPED: Shaped = Shaped(Mutex::new(Vec::new()));
+    static SHAPED_PAGES: [&dyn added::Page; 1] = [&SHAPED];
+
+    #[test]
+    fn half_buttons_share_a_row_and_an_inactive_one_is_never_pressed() {
+        let mut s = Settings::default();
+        TEST_PAGES.set(Some(&SHAPED_PAGES));
+        let ui = OptionsUi::default();
+        let rows = ui.added_rows(0);
+        // The two texts as notes (space shows nothing here), the halves on one row, the
+        // footer button below them (the settings shell has no footer of its own).
+        assert!(matches!(&rows[0], Row::Note(t) if t == "ABCDE-FGHIJ"));
+        assert!(matches!(&rows[1], Row::Note(t) if t == "grey"));
+        let Row::Buttons(copy, Some(stop)) = &rows[2] else {
+            panic!("the halves sit side by side: {:?}", rows.len());
+        };
+        assert_eq!((copy.w, stop.w), (150.0, 150.0));
+        assert!(matches!(&rows[3], Row::Buttons(help, None) if help.w == 310.0));
+        assert_eq!(rows.len(), 4);
+        let mut ui = ui;
+        ui.show(Page::Added(0));
+        press(&mut ui, &mut s, Act::PageRow(0, 3), false);
+        press(&mut ui, &mut s, Act::PageRow(0, 5), false);
+        let (widgets, ..) = ui.layout(&s, 480.0, 240.0);
+        let stop = widgets
+            .iter()
+            .find(|w| {
+                matches!(
+                    &w.kind,
+                    WKind::Button {
+                        act: Act::PageRow(0, 4),
+                        ..
+                    }
+                )
+            })
+            .expect("Stop is drawn");
+        let atlas = super::super::tests::atlas();
+        ui.click(
+            &mut s,
+            &atlas,
+            stop.x + 1.0,
+            stop.y + 1.0,
+            (480.0, 240.0),
+            [480, 240],
+            false,
+            false,
+        );
+        assert_eq!(
+            *SHAPED.0.lock().unwrap(),
+            [3, 5],
+            "the inactive half heard nothing"
+        );
+    }
 }

crates/horizon-client-render/src/pack_formats/block_entity_cem.rs

@@ -12,6 +12,7 @@
 //! block models here, so their files are not read; copper golem statues have no CEM name.
 
 use crate::block_entity_render::ModelPart;
+use crate::pack_hooks::Reshaped;
 use horizon_optifine::cem::{
     files::{atlas_name, jem_files, load_jem},
     model::{Bone, EntityModel},
@@ -140,12 +141,6 @@ const TARGETS: &[Target] = &[
     model("decorated_pot_sides", &["decorated_pot"], POT_SIDES),
 ];
 
-/// Every model, reshaped or vanilla's, and the atlas names of the `.jem` textures by model.
-pub type Reshaped = (
-    HashMap<&'static str, ModelPart>,
-    HashMap<&'static str, String>,
-);
-
 /// The models the packs under `root` reshape, over `vanilla`'s; None when no block entity has
 /// a `.jem` there.
 pub fn reshape(root: &Path, vanilla: &HashMap<&'static str, ModelPart>) -> Option<Reshaped> {

crates/horizon-client-render/src/pack_formats/cit.rs

@@ -0,0 +1,969 @@
+//! OptiFine's Custom Item Textures (and CIT Resewn's): the rules of the enabled packs'
+//! `optifine/cit/**/*.properties`, read from the overlay resource root, and which of them a stack
+//! matches ([`crate::cit::Matcher`]). The rules themselves are `horizon_optifine::cit`'s; the
+//! engine gets them as [`crate::cit::Rule`]s.
+
+use super::cit_glint::{load_global, stack_glint};
+use crate::cit::{self as engine, CitRules};
+use crate::cit_glint::StackGlint;
+use horizon_client_core::component::name_text;
+use horizon_client_core::scoreboard::comp_text;
+use horizon_items::item_data::{canon_tag, encode_components};
+use horizon_items::items::ItemStack;
+use horizon_optifine::cit::{
+    Blend, ComponentTest, Factor, Glint, Global, Hand, Kind, Rule, Source, ValueTest,
+};
+use horizon_optifine::{Properties, properties_files_in};
+use horizon_world::nbt::{JavaString, Tag, parse_snbt};
+use std::borrow::Cow;
+use std::collections::HashMap;
+use std::fs;
+use std::hash::{DefaultHasher, Hash, Hasher};
+use std::path::Path;
+use std::sync::{Arc, Mutex};
+
+/// Every rule under the root's `optifine/cit/`, `mcpatcher/cit/` and CIT Resewn's
+/// `citresewn/cit/` folders, the one chosen first when several match first (`Rule::priority`).
+/// The pack's global `cit.properties` is not a rule.
+pub fn load_rules(root: &Path) -> Vec<Rule> {
+    let tops = ["optifine", "mcpatcher", "citresewn"];
+    let mut rules: Vec<Rule> = properties_files_in(root, &tops, "cit")
+        .into_iter()
+        .filter(|path| !path.ends_with("/cit.properties"))
+        .filter_map(|path| {
+            let props = read_properties(&root.join(&path))?;
+            let rule = Rule::parse(&path, &props, |p| root.join(p).is_file());
+            if rule.is_none() {
+                log::warn!("custom item textures: {path} is not a rule Horizon can read");
+            }
+            rule
+        })
+        .collect();
+    rules.sort_by(Rule::priority);
+    rules
+}
+
+/// A `.properties` file as CIT Resewn reads them (`Properties::parse_equals_first`): UTF-8,
+/// else Latin-1 as Java reads them, so a pack saved that way still loads. `None` when it can't
+/// be read.
+pub fn read_properties(path: &Path) -> Option<Properties> {
+    let bytes = fs::read(path).ok()?;
+    let text = String::from_utf8(bytes)
+        .unwrap_or_else(|e| e.into_bytes().iter().map(|&b| char::from(b)).collect());
+    Some(Properties::parse_equals_first(&text))
+}
+
+/// The rules at `root` with the pack's `cit.properties`, as the engine draws and matches them.
+pub fn load(root: &Path) -> CitRules {
+    cit_rules(load_rules(root), load_global(root))
+}
+
+/// `rules` (in priority order, the winner first) under `global`, for the engine.
+pub fn cit_rules(rules: Vec<Rule>, global: Global) -> CitRules {
+    let drawn = rules.iter().map(rule).collect();
+    let use_glint = global.use_glint;
+    CitRules::new(drawn, use_glint, Box::new(Matcher::new(rules, global)))
+}
+
+/// A rule's file as the engine draws it: `text` read as the `.properties` file at `path`, every
+/// file it names taken to exist. For tests and tools.
+pub fn parse_rule(path: &str, text: &str) -> Option<engine::Rule> {
+    Rule::parse(path, &Properties::parse_equals_first(text), |_| true).map(|r| rule(&r))
+}
+
+/// [`parse_rule`] for a rule in the pack at `root`, whose files it looks for there.
+pub fn parse_rule_in(root: &Path, path: &str, text: &str) -> Option<engine::Rule> {
+    let props = Properties::parse_equals_first(text);
+    Rule::parse(path, &props, |p| root.join(p).is_file()).map(|r| rule(&r))
+}
+
+/// Rules from (path, `.properties` text) under the global `cit.properties` text `global`, in
+/// priority order, every file they name taken to exist. For tests and tools.
+pub fn parse_rules(files: &[(&str, &str)], global: &str) -> CitRules {
+    let mut rules: Vec<Rule> = files
+        .iter()
+        .filter_map(|(path, text)| {
+            Rule::parse(path, &Properties::parse_equals_first(text), |_| true)
+        })
+        .collect();
+    rules.sort_by(Rule::priority);
+    cit_rules(
+        rules,
+        Global::parse(&Properties::parse_equals_first(global)),
+    )
+}
+
+/// A `blend=` value as the engine draws it ([`horizon_optifine::cit::parse_blend`]). For tests
+/// and tools.
+pub fn parse_blend(value: &str) -> Option<Option<engine::Blend>> {
+    horizon_optifine::cit::parse_blend(value).map(|b| b.map(blend))
+}
+
+fn rule(r: &Rule) -> engine::Rule {
+    engine::Rule {
+        path: r.path.clone(),
+        kind: kind(r.kind),
+        texture: r.texture.clone(),
+        textures: r.textures.clone(),
+        model: r.model.clone(),
+        models: r.models.clone(),
+        glint: glint(&r.glint),
+    }
+}
+
+fn kind(k: Kind) -> engine::Kind {
+    match k {
+        Kind::Item => engine::Kind::Item,
+        Kind::Armor => engine::Kind::Armor,
+        Kind::Elytra => engine::Kind::Elytra,
+        Kind::Enchantment => engine::Kind::Enchantment,
+    }
+}
+
+fn of_kind(k: engine::Kind) -> Kind {
+    match k {
+        engine::Kind::Item => Kind::Item,
+        engine::Kind::Armor => Kind::Armor,
+        engine::Kind::Elytra => Kind::Elytra,
+        engine::Kind::Enchantment => Kind::Enchantment,
+    }
+}
+
+fn of_hand(h: engine::Hand) -> Hand {
+    match h {
+        engine::Hand::Any => Hand::Any,
+        engine::Hand::Main => Hand::Main,
+        engine::Hand::Off => Hand::Off,
+    }
+}
+
+fn glint(g: &Glint) -> engine::Glint {
+    engine::Glint {
+        layer: g.layer,
+        blend: g.blend.map(blend),
+        speed: g.speed,
+        rotation: g.rotation,
+        duration: g.duration,
+        rgba: g.rgba,
+        use_glint: g.use_glint,
+        blur: g.blur,
+    }
+}
+
+fn blend(b: Blend) -> engine::Blend {
+    engine::Blend {
+        src: factor(b.src),
+        dst: factor(b.dst),
+        src_alpha: factor(b.src_alpha),
+        dst_alpha: factor(b.dst_alpha),
+    }
+}
+
+fn factor(f: Factor) -> engine::Factor {
+    use engine::Factor as F;
+    match f {
+        Factor::Zero => F::Zero,
+        Factor::One => F::One,
+        Factor::SrcColor => F::SrcColor,
+        Factor::OneMinusSrcColor => F::OneMinusSrcColor,
+        Factor::SrcAlpha => F::SrcAlpha,
+        Factor::OneMinusSrcAlpha => F::OneMinusSrcAlpha,
+        Factor::DstAlpha => F::DstAlpha,
+        Factor::OneMinusDstAlpha => F::OneMinusDstAlpha,
+        Factor::DstColor => F::DstColor,
+        Factor::OneMinusDstColor => F::OneMinusDstColor,
+        Factor::SrcAlphaSaturate => F::SrcAlphaSaturate,
+    }
+}
+
+/// The rules with an index by item and a cache of what each stack matched.
+#[derive(Debug, Default)]
+struct Matcher {
+    rules: Vec<Rule>,
+    /// The pack's `cit.properties`.
+    global: Global,
+    /// Per kind (`Kind as usize`), the rules naming each item, in priority order.
+    by_item: [HashMap<String, Vec<u32>>; 4],
+    /// Enchantment rules without `items`, in priority order.
+    any_item: Vec<u32>,
+    /// Per rule, per component test: its literal read as SNBT and as a JSON text component.
+    literals: Vec<Vec<Prepared>>,
+    selected: Mutex<HashMap<u64, Option<u32>>>,
+    enchanted: Mutex<HashMap<u64, Vec<u32>>>,
+    glints: Mutex<HashMap<u64, Arc<StackGlint>>>,
+}
+
+#[derive(Debug, Default)]
+struct Prepared {
+    snbt: Option<Tag>,
+    json: Option<String>,
+}
+
+/// Cache entries kept before the cache starts over.
+const CACHE_LIMIT: usize = 4096;
+
+impl Matcher {
+    /// `rules` in priority order, the winner first.
+    fn new(rules: Vec<Rule>, global: Global) -> Self {
+        let mut by_item: [HashMap<String, Vec<u32>>; 4] = Default::default();
+        let mut any_item = Vec::new();
+        for (i, rule) in rules.iter().enumerate() {
+            let i = i as u32;
+            if rule.kind == Kind::Enchantment && rule.items.is_empty() {
+                any_item.push(i);
+            }
+            for item in &rule.items {
+                let list = by_item[rule.kind as usize].entry(item.clone()).or_default();
+                if list.last() != Some(&i) {
+                    list.push(i);
+                }
+            }
+        }
+        let literals = rules
+            .iter()
+            .map(|r| r.components.iter().map(prepare).collect())
+            .collect();
+        Self {
+            rules,
+            global,
+            by_item,
+            any_item,
+            literals,
+            ..Default::default()
+        }
+    }
+
+    /// Whether rule `i` matches the stack drawn in `hand`.
+    fn matches(
+        &self,
+        i: u32,
+        stack: &ItemStack,
+        hand: Hand,
+        max_damage: u32,
+        comps: Option<&Tag>,
+    ) -> bool {
+        let rule = &self.rules[i as usize];
+        if rule.hand != Hand::Any && rule.hand != hand {
+            return false;
+        }
+        let count = i32::try_from(stack.count).unwrap_or(i32::MAX);
+        if rule.stack_size.as_ref().is_some_and(|r| !r.contains(count)) {
+            return false;
+        }
+        // CIT Resewn: only damageable items have damage.
+        let damage = if max_damage > 0 { stack.damage } else { 0 };
+        if rule
+            .damage
+            .as_ref()
+            .is_some_and(|d| !d.matches(damage, max_damage))
+        {
+            return false;
+        }
+        let enchantments = stack.crafting_enchantments();
+        let listed = |id: &str| rule.enchantments.iter().any(|e| e == id);
+        if !rule.enchantments.is_empty() && !enchantments.iter().any(|(id, _)| listed(id)) {
+            return false;
+        }
+        if let Some(levels) = &rule.enchantment_levels {
+            let level_in_range = enchantments.iter().any(|(id, level)| {
+                (rule.enchantments.is_empty() || listed(id))
+                    && levels.contains(i32::try_from(*level).unwrap_or(i32::MAX))
+            });
+            if !level_in_range {
+                return false;
+            }
+        }
+        let literals = &self.literals[i as usize];
+        rule.components
+            .iter()
+            .zip(literals)
+            .all(|(test, lit)| component_test(test, lit, stack, comps) != test.negate)
+    }
+}
+
+impl engine::Matcher for Matcher {
+    fn keep_glints(&mut self, keep: &dyn Fn(usize) -> bool) {
+        self.any_item.retain(|&i| keep(i as usize));
+        let named = &mut self.by_item[Kind::Enchantment as usize];
+        for list in named.values_mut() {
+            list.retain(|&i| keep(i as usize));
+        }
+        named.retain(|_, list| !list.is_empty());
+        lock(&self.enchanted).clear();
+        lock(&self.glints).clear();
+    }
+
+    fn select(
+        &self,
+        kind: engine::Kind,
+        stack: &ItemStack,
+        hand: engine::Hand,
+        max_damage: u32,
+    ) -> Option<usize> {
+        let (kind, hand) = (of_kind(kind), of_hand(hand));
+        let candidates = self.by_item[kind as usize].get(&*stack.item)?;
+        let comps = encode_components(stack);
+        let key = cache_key((0, kind, hand), stack, max_damage, comps.as_ref());
+        if let Some(hit) = lock(&self.selected).get(&key) {
+            return hit.map(|i| i as usize);
+        }
+        let found = candidates
+            .iter()
+            .copied()
+            .find(|&i| self.matches(i, stack, hand, max_damage, comps.as_ref()));
+        remember(&self.selected, key, found);
+        found.map(|i| i as usize)
+    }
+
+    fn enchantments(&self, stack: &ItemStack, hand: engine::Hand, max_damage: u32) -> Vec<usize> {
+        let hand = of_hand(hand);
+        let named = self.by_item[Kind::Enchantment as usize]
+            .get(&*stack.item)
+            .map_or(&[][..], Vec::as_slice);
+        if named.is_empty() && self.any_item.is_empty() {
+            return Vec::new();
+        }
+        let comps = encode_components(stack);
+        let key = cache_key(
+            (1, Kind::Enchantment, hand),
+            stack,
+            max_damage,
+            comps.as_ref(),
+        );
+        let hit = lock(&self.enchanted).get(&key).cloned();
+        let found = hit.unwrap_or_else(|| {
+            let mut all: Vec<u32> = named.iter().chain(&self.any_item).copied().collect();
+            all.sort_unstable();
+            all.retain(|&i| self.matches(i, stack, hand, max_damage, comps.as_ref()));
+            remember(&self.enchanted, key, all.clone());
+            all
+        });
+        found.into_iter().map(|i| i as usize).collect()
+    }
+
+    /// Worked out once per stack and hand.
+    fn glint(
+        &self,
+        stack: &ItemStack,
+        hand: engine::Hand,
+        max_damage: u32,
+        foil: bool,
+    ) -> Option<Arc<StackGlint>> {
+        let no_rules =
+            self.any_item.is_empty() && self.by_item[Kind::Enchantment as usize].is_empty();
+        // Before the cache, which `foil` is not part of.
+        if !foil || (no_rules && self.global.use_glint) {
+            return None;
+        }
+        let comps = encode_components(stack);
+        let key = cache_key(
+            (2, Kind::Enchantment, of_hand(hand)),
+            stack,
+            max_damage,
+            comps.as_ref(),
+        );
+        if let Some(hit) = lock(&self.glints).get(&key) {
+            return Some(hit.clone());
+        }
+        let matched = self.enchantments(stack, hand, max_damage);
+        let glint = Arc::new(stack_glint(
+            &self.rules,
+            &matched,
+            stack.crafting_enchantments(),
+            &self.global,
+        ));
+        remember(&self.glints, key, glint.clone());
+        Some(glint)
+    }
+}
+
+fn lock<T>(m: &Mutex<T>) -> std::sync::MutexGuard<'_, T> {
+    m.lock().unwrap_or_else(|e| e.into_inner())
+}
+
+fn remember<V>(cache: &Mutex<HashMap<u64, V>>, key: u64, value: V) {
+    let mut cache = lock(cache);
+    if cache.len() >= CACHE_LIMIT {
+        cache.clear();
+    }
+    cache.insert(key, value);
+}
+
+/// What a cached answer depends on; `query` tells `select`, `enchantments` and `glint` apart.
+fn cache_key(query: (u8, Kind, Hand), stack: &ItemStack, max: u32, comps: Option<&Tag>) -> u64 {
+    let mut h = DefaultHasher::new();
+    (query.0, query.1 as u8, query.2 as u8, &*stack.item).hash(&mut h);
+    (stack.count, stack.damage, max, comps).hash(&mut h);
+    h.finish()
+}
+
+fn prepare(test: &ComponentTest) -> Prepared {
+    let ValueTest::Literal(lit) = &test.value else {
+        return Prepared::default();
+    };
+    let text = lit.text.trim();
+    let snbt = match parse_snbt(text) {
+        Ok((tag, read)) if read == text.len() && text.starts_with(['{', '[']) => Some(tag),
+        _ => None,
+    };
+    let json = json_plain(text);
+    Prepared { snbt, json }
+}
+
+/// The plain text of `s` read as a JSON text component.
+fn json_plain(s: &str) -> Option<String> {
+    if !s.starts_with(['{', '[', '"']) {
+        return None;
+    }
+    let value: serde_json::Value = serde_json::from_str(s).ok()?;
+    Some(comp_text(&value).plain())
+}
+
+/// Whether one test passes, before its `negate`.
+fn component_test(
+    test: &ComponentTest,
+    lit: &Prepared,
+    stack: &ItemStack,
+    comps: Option<&Tag>,
+) -> bool {
+    let legacy;
+    let (root, text_depth) = match &test.source {
+        Source::Component(id) => {
+            let depth = match id.as_str() {
+                "minecraft:custom_name" | "minecraft:item_name" => Some(0),
+                "minecraft:lore" => Some(1),
+                _ => None,
+            };
+            (comps.and_then(|c| c.get(id)), depth)
+        }
+        Source::LegacyEnchantments { stored } => {
+            let levels = if *stored {
+                stack.stored_enchantments()
+            } else {
+                stack.enchantments()
+            };
+            legacy = Tag::List(
+                levels
+                    .iter()
+                    .map(|(id, lvl)| {
+                        let lvl = i16::try_from(*lvl).unwrap_or(i16::MAX);
+                        Tag::compound([
+                            ("id", Tag::String((&**id).into())),
+                            ("lvl", Tag::Short(lvl)),
+                        ])
+                    })
+                    .collect(),
+            );
+            (Some(&legacy), None)
+        }
+    };
+    // Fields the component leaves out when 0, which pre-1.20.5 items always wrote.
+    let defaulted;
+    let root = match (&test.source, root, test.path.first()) {
+        (Source::Component(id), Some(Tag::Compound(map)), Some(field))
+            if matches!(
+                (id.as_str(), field.as_str()),
+                ("minecraft:written_book_content", "generation")
+                    | ("minecraft:fireworks", "flight_duration")
+            ) && !map.contains_key(&JavaString::from(field.as_str())) =>
+        {
+            let mut map = map.clone();
+            map.insert(JavaString::from(field.as_str()), Tag::Int(0));
+            defaulted = Tag::Compound(map);
+            Some(&defaulted)
+        }
+        (_, root, _) => root,
+    };
+    let Some(root) = root else {
+        return matches!(test.value, ValueTest::Exists(false));
+    };
+    if let ValueTest::Exists(want) = test.value {
+        return walk(root, &test.path, 0, &mut |_, _| true) == want;
+    }
+    walk(root, &test.path, 0, &mut |tag, depth| {
+        value_test(&test.value, lit, tag, text_depth == Some(depth))
+    })
+}
+
+/// Visits what `path` reaches from `tag`, true once `visit` is.
+fn walk(
+    tag: &Tag,
+    path: &[String],
+    depth: usize,
+    visit: &mut dyn FnMut(&Tag, usize) -> bool,
+) -> bool {
+    let Some((seg, rest)) = path.split_first() else {
+        return visit(tag, depth);
+    };
+    let mut next = |t: &Tag| walk(t, rest, depth + 1, visit);
+    let len = match tag {
+        Tag::Compound(map) if seg == "*" => return map.values().any(&mut next),
+        Tag::Compound(map) => return map.get(&JavaString::from(seg.as_str())).is_some_and(next),
+        Tag::List(v) => v.len(),
+        Tag::ByteArray(v) => v.len(),
+        Tag::IntArray(v) => v.len(),
+        Tag::LongArray(v) => v.len(),
+        _ => return false,
+    };
+    let element = |i: usize| match tag {
+        Tag::List(v) => Cow::Borrowed(&v[i]),
+        Tag::ByteArray(v) => Cow::Owned(Tag::Byte(v[i] as i8)),
+        Tag::IntArray(v) => Cow::Owned(Tag::Int(v[i])),
+        Tag::LongArray(v) => Cow::Owned(Tag::Long(v[i])),
+        _ => Cow::Owned(Tag::End),
+    };
+    if seg == "count" {
+        return next(&Tag::Int(i32::try_from(len).unwrap_or(i32::MAX)));
+    }
+    if seg == "*" {
+        return (0..len).any(|i| next(&element(i)));
+    }
+    seg.parse::<usize>()
+        .ok()
+        .filter(|&i| i < len)
+        .is_some_and(|i| next(&element(i)))
+}
+
+fn int_value(tag: &Tag) -> Option<i64> {
+    match *tag {
+        Tag::Byte(v) => Some(v.into()),
+        Tag::Short(v) => Some(v.into()),
+        Tag::Int(v) => Some(v.into()),
+        Tag::Long(v) => Some(v),
+        _ => None,
+    }
+}
+
+/// A number as Java's `String.valueOf` writes it (`3`, `3.0`).
+fn decimal(tag: &Tag) -> Option<String> {
+    let s = match *tag {
+        Tag::Float(b) => f32::from_bits(b).to_string(),
+        Tag::Double(b) => f64::from_bits(b).to_string(),
+        _ => return int_value(tag).map(|v| v.to_string()),
+    };
+    Some(if s.contains(['.', 'e', 'N', 'i']) {
+        s
+    } else {
+        s + ".0"
+    })
+}
+
+/// `text` against a string, its JSON text, or the plain text of a text component.
+fn text_matches(tag: &Tag, is_text: bool, text: impl Fn(&str) -> bool) -> bool {
+    match tag {
+        Tag::String(s) => {
+            let s = s.to_string_lossy();
+            text(&s)
+                || (is_text && text(&name_text(tag).plain()))
+                || json_plain(&s).is_some_and(|p| text(&p))
+        }
+        Tag::Compound(_) | Tag::List(_) => is_text && text(&name_text(tag).plain()),
+        _ => false,
+    }
+}
+
+fn value_test(test: &ValueTest, lit: &Prepared, tag: &Tag, is_text: bool) -> bool {
+    match test {
+        ValueTest::Exists(_) => true,
+        ValueTest::Range(r) => {
+            int_value(tag).is_some_and(|v| i32::try_from(v).is_ok_and(|v| r.contains(v)))
+        }
+        ValueTest::Raw(name) => name.matches(&canon_tag(tag)),
+        ValueTest::Text(name) => match decimal(tag) {
+            Some(n) => name.matches(&n),
+            None => text_matches(tag, is_text, |s| name.matches(s)),
+        },
+        ValueTest::Literal(l) => match tag {
+            Tag::Float(b) => l.text.trim().parse::<f32>().ok() == Some(f32::from_bits(*b)),
+            Tag::Double(b) => l.float == Some(f64::from_bits(*b)),
+            Tag::Compound(_) | Tag::List(_)
+                if lit.snbt.as_ref().is_some_and(|e| contains(e, tag)) =>
+            {
+                true
+            }
+            _ => match int_value(tag) {
+                Some(v) => l.int == Some(v),
+                None => text_matches(tag, is_text, |s| {
+                    s == l.text || lit.json.as_deref() == Some(s)
+                }),
+            },
+        },
+    }
+}
+
+/// `NbtUtils.compareNbt(expected, actual, true)`: every key and element of `expected` found in
+/// `actual`.
+fn contains(expected: &Tag, actual: &Tag) -> bool {
+    match (expected, actual) {
+        (Tag::Compound(e), Tag::Compound(a)) => e
+            .iter()
+            .all(|(k, v)| a.get(k).is_some_and(|a| contains(v, a))),
+        (Tag::List(e), Tag::List(a)) if e.is_empty() => a.is_empty(),
+        (Tag::List(e), Tag::List(a)) => e.iter().all(|e| a.iter().any(|a| contains(e, a))),
+        _ => expected == actual,
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::cit::{Hand, Kind};
+    use std::sync::Arc;
+
+    /// Rules from (file stem, properties), sorted as `load_rules` sorts them, under the global
+    /// `cit.properties` text `global`.
+    fn rules_under(files: &[(&str, &str)], global: &str) -> CitRules {
+        let files: Vec<(String, String)> = files
+            .iter()
+            .map(|(stem, text)| {
+                let path = format!("assets/minecraft/optifine/cit/{stem}.properties");
+                (path, format!("texture=x\n{text}"))
+            })
+            .collect();
+        let files: Vec<(&str, &str)> = files.iter().map(|(p, t)| (&**p, &**t)).collect();
+        let cit = parse_rules(&files, global);
+        assert_eq!(cit.rules.len(), files.len(), "every rule parses");
+        cit
+    }
+
+    fn rules(files: &[(&str, &str)]) -> CitRules {
+        rules_under(files, "")
+    }
+
+    fn stem(cit: &CitRules, i: Option<usize>) -> Option<&str> {
+        let path = &cit.rules[i?].path;
+        path.rsplit('/').next()?.strip_suffix(".properties")
+    }
+
+    fn item(cit: &CitRules, stack: ItemStack) -> Option<&str> {
+        stem(cit, cit.select(Kind::Item, &stack, Hand::Main, 0))
+    }
+
+    fn new(id: &str) -> ItemStack {
+        ItemStack::new(&format!("minecraft:{id}"), 1)
+    }
+
+    fn string(s: &str) -> Tag {
+        Tag::String(s.into())
+    }
+
+    fn with(id: &str, component: &str, tag: Tag) -> ItemStack {
+        let mut stack = new(id);
+        let component = format!("minecraft:{component}");
+        stack.data_mut().other.push((component, tag));
+        stack
+    }
+
+    fn enchanted(id: &str, levels: &[(&str, u32)]) -> ItemStack {
+        let mut stack = new(id);
+        let levels = levels
+            .iter()
+            .map(|(e, l)| (Arc::from(format!("minecraft:{e}")), *l));
+        stack.data_mut().enchantments = levels.collect();
+        stack
+    }
+
+    #[test]
+    fn heavier_rules_win_and_kinds_stay_apart() {
+        let cit = rules(&[
+            ("plain", "items=stick"),
+            ("heavy", "items=stick\nweight=2\nstackSize=2-"),
+            ("offhand", "items=stick\nweight=5\nhand=off"),
+            ("armor", "type=armor\nitems=stick"),
+            ("wings", "type=elytra"),
+        ]);
+        assert_eq!(item(&cit, new("stick")), Some("plain"));
+        assert_eq!(
+            item(&cit, ItemStack::new("minecraft:stick", 3)),
+            Some("heavy")
+        );
+        let pick = |kind, id, hand, max| stem(&cit, cit.select(kind, &new(id), hand, max));
+        assert_eq!(pick(Kind::Item, "stick", Hand::Off, 0), Some("offhand"));
+        assert_eq!(item(&cit, new("stone")), None);
+        assert_eq!(item(&cit, new("elytra")), None);
+        assert_eq!(pick(Kind::Elytra, "elytra", Hand::Main, 432), Some("wings"));
+        assert_eq!(pick(Kind::Armor, "stick", Hand::Main, 0), Some("armor"));
+    }
+
+    #[test]
+    fn names_match_by_their_plain_text() {
+        let cit = rules(&[
+            ("glob", "items=stick\nnbt.display.Name=ipattern:*sword"),
+            ("exact", "items=stone\ncomponents.custom_name=My Sword"),
+            ("json", "items=dirt\nnbt.display.Name=[\"My \",\"Sword\"]"),
+        ]);
+        let named = |id: &str, name: Tag| {
+            let mut stack = new(id);
+            stack.data_mut().custom_name = Some(name);
+            stack
+        };
+        let styled = Tag::compound([("text", string("My Sword")), ("color", string("red"))]);
+        assert_eq!(item(&cit, named("stick", styled.clone())), Some("glob"));
+        assert_eq!(item(&cit, named("stick", string("Blade"))), None);
+        assert_eq!(item(&cit, new("stick")), None);
+        assert_eq!(item(&cit, named("stone", styled.clone())), Some("exact"));
+        assert_eq!(item(&cit, named("dirt", styled)), Some("json"));
+    }
+
+    #[test]
+    fn lore_lines_and_list_counts() {
+        let cit = rules(&[
+            (
+                "any_line",
+                "items=stick\nnbt.display.Lore.*=ipattern:*legendary*",
+            ),
+            ("two_lines", "items=stone\ncomponents.lore.count=2"),
+        ]);
+        let bold = Tag::compound([("text", string("A LEGENDARY item")), ("bold", Tag::Byte(1))]);
+        let lore = Tag::List(vec![string("Common"), bold]);
+        assert_eq!(
+            item(&cit, with("stick", "lore", lore.clone())),
+            Some("any_line")
+        );
+        assert_eq!(item(&cit, with("stone", "lore", lore)), Some("two_lines"));
+        let one = Tag::List(vec![string("A legendary item")]);
+        assert_eq!(item(&cit, with("stone", "lore", one)), None);
+    }
+
+    #[test]
+    fn custom_data_existence_and_negation() {
+        let cit = rules(&[
+            (
+                "aote",
+                "items=stick\nweight=2\nnbt.ExtraAttributes.id=ASPECT_OF_THE_END",
+            ),
+            (
+                "not_hyp",
+                "items=stick\nweight=1\ncomponent.custom_data.ExtraAttributes.id=!HYP",
+            ),
+            ("unnamed", "items=stick\nnbt.display.Name=exists:false"),
+        ]);
+        let data = |id: &str| {
+            let attributes =
+                Tag::compound([("ExtraAttributes", Tag::compound([("id", string(id))]))]);
+            with("stick", "custom_data", attributes)
+        };
+        assert_eq!(item(&cit, data("ASPECT_OF_THE_END")), Some("aote"));
+        assert_eq!(item(&cit, data("MIDAS")), Some("not_hyp"));
+        assert_eq!(item(&cit, data("HYP")), Some("unnamed"));
+        let mut named = data("HYP");
+        named.data_mut().custom_name = Some(string("Hyperion"));
+        assert_eq!(item(&cit, named), None);
+    }
+
+    #[test]
+    fn legacy_enchantment_lists_and_model_data() {
+        let cit = rules(&[
+            (
+                "sharp",
+                "items=stick\nnbt.Enchantments.*.id=minecraft:sharpness\nnbt.Enchantments.0.lvl=5",
+            ),
+            ("cmd", "items=stone\nnbt.CustomModelData=3"),
+            (
+                "cmd_snbt",
+                "items=dirt\ncomponents.custom_model_data={floats:[3.0f]}",
+            ),
+        ]);
+        assert_eq!(
+            item(&cit, enchanted("stick", &[("sharpness", 5)])),
+            Some("sharp")
+        );
+        assert_eq!(item(&cit, enchanted("stick", &[("sharpness", 4)])), None);
+        let model = |id: &str, f: f32| {
+            let floats = Tag::List(vec![Tag::Float(f.to_bits()), Tag::Float(7f32.to_bits())]);
+            with(id, "custom_model_data", Tag::compound([("floats", floats)]))
+        };
+        assert_eq!(item(&cit, model("stone", 3.0)), Some("cmd"));
+        assert_eq!(item(&cit, model("stone", 3.5)), None);
+        assert_eq!(item(&cit, model("dirt", 3.0)), Some("cmd_snbt"));
+        assert_eq!(item(&cit, model("dirt", 2.0)), None);
+    }
+
+    #[test]
+    fn fields_left_out_at_zero_read_as_zero() {
+        let cit = rules(&[("zero", "items=firework_rocket\nnbt.Fireworks.Flight=0")]);
+        let mut rocket = new("firework_rocket");
+        rocket.data_mut().fireworks = Some((0, Vec::new()));
+        assert_eq!(item(&cit, rocket.clone()), Some("zero"));
+        rocket.data_mut().fireworks = Some((2, Vec::new()));
+        assert_eq!(item(&cit, rocket), None);
+    }
+
+    #[test]
+    fn damage_counts_only_for_damageable_items() {
+        let cit = rules(&[
+            ("worn", "items=diamond_sword\ndamage=50-100%"),
+            ("new", "items=stick\ndamage=0"),
+        ]);
+        let damaged = |id: &str, damage: u32, max: u32| {
+            let mut stack = new(id);
+            stack.damage = damage;
+            stem(&cit, cit.select(Kind::Item, &stack, Hand::Main, max))
+        };
+        // Half of 1561 is 780.5.
+        assert_eq!(damaged("diamond_sword", 780, 1561), None);
+        assert_eq!(damaged("diamond_sword", 781, 1561), Some("worn"));
+        assert_eq!(damaged("stick", 5, 0), Some("new"));
+    }
+
+    #[test]
+    fn enchantment_levels_and_rules_for_any_item() {
+        let cit = rules(&[
+            (
+                "sharp3",
+                "items=stick\nenchantments=sharpness\nenchantmentLevels=3-",
+            ),
+            ("any3", "items=stone\nenchantmentLevels=3-"),
+            ("glint", "type=enchantment\nenchantments=sharpness"),
+            (
+                "sword_glint",
+                "type=enchantment\nitems=diamond_sword\nweight=2",
+            ),
+        ]);
+        let mixed = [("sharpness", 2), ("unbreaking", 3)];
+        assert_eq!(item(&cit, enchanted("stick", &mixed)), None);
+        assert_eq!(
+            item(&cit, enchanted("stick", &[("sharpness", 4)])),
+            Some("sharp3")
+        );
+        assert_eq!(item(&cit, enchanted("stone", &mixed)), Some("any3"));
+        let glints = |stack: ItemStack| -> Vec<&str> {
+            let found = cit.enchantments(&stack, Hand::Main, 0).into_iter();
+            found.map(|i| stem(&cit, Some(i)).unwrap()).collect()
+        };
+        let sharp = [("sharpness", 1)];
+        assert_eq!(
+            glints(enchanted("diamond_sword", &sharp)),
+            ["sword_glint", "glint"]
+        );
+        assert_eq!(glints(enchanted("stick", &sharp)), ["glint"]);
+        assert!(glints(new("stick")).is_empty());
+        // Glints are never an item's texture.
+        assert_eq!(item(&cit, enchanted("diamond_sword", &sharp)), None);
+    }
+
+    /// `CitRules::glint` in the main hand, with the stack's own `has_foil` as callers pass it.
+    fn glint(cit: &CitRules, stack: &ItemStack, item_glint: bool) -> Option<Arc<StackGlint>> {
+        cit.glint(stack, Hand::Main, 0, stack.has_foil(item_glint))
+    }
+
+    /// `stack` with its `enchantment_glint_override` set to `on`.
+    fn overridden(mut stack: ItemStack, on: bool) -> ItemStack {
+        let flag = (
+            "minecraft:enchantment_glint_override".to_owned(),
+            Tag::Byte(on.into()),
+        );
+        stack.data_mut().other.push(flag);
+        stack
+    }
+
+    #[test]
+    fn a_stack_glint_reads_the_book_and_the_pack_file() {
+        let files = [
+            ("sharp", "type=enchantment\nenchantments=sharpness"),
+            (
+                "keep",
+                "type=enchantment\nlayer=1\nuseGlint=true\nenchantments=mending",
+            ),
+        ];
+        let cit = rules(&files);
+        // An enchanted book's glint follows its stored enchantments.
+        let mut book = new("enchanted_book");
+        book.data_mut().stored_enchantments = vec![
+            (Arc::from("minecraft:sharpness"), 3),
+            (Arc::from("minecraft:mending"), 1),
+        ];
+        let book = glint(&cit, &book, true).unwrap();
+        let weights: Vec<_> = book.layers.iter().map(|l| l.weight).collect();
+        assert_eq!(weights, [0.75, 0.25]);
+        assert!(book.vanilla);
+        let plain = glint(&cit, &enchanted("stick", &[("sharpness", 1)]), false).unwrap();
+        assert_eq!(plain.layers.len(), 1);
+        assert!(!plain.vanilla);
+        // No enchantment rules: nothing changes, unless the pack turns vanilla's glint off.
+        let bare = rules(&[("stick", "items=stick")]);
+        assert!(glint(&bare, &overridden(new("stick"), true), false).is_none());
+        let bare = rules_under(&[("stick", "items=stick")], "useGlint=false");
+        assert!(!bare.use_glint);
+        assert!(
+            !glint(&bare, &overridden(new("stick"), true), false)
+                .unwrap()
+                .vanilla
+        );
+        let cit = rules_under(&files, "useGlint=false");
+        assert!(
+            glint(&cit, &overridden(new("stick"), true), false)
+                .unwrap()
+                .is_empty()
+        );
+    }
+
+    #[test]
+    fn only_a_stack_with_a_glint_gets_layers() {
+        let cit = rules(&[("any", "type=enchantment")]);
+        assert!(glint(&cit, &new("stick"), false).is_none());
+        // The override turns an enchanted stack's glint off, and an unenchanted one's on.
+        let off = overridden(enchanted("stick", &[("sharpness", 1)]), false);
+        assert!(glint(&cit, &off, false).is_none());
+        let on = glint(&cit, &overridden(new("stick"), true), false).unwrap();
+        let weights: Vec<_> = on.layers.iter().map(|l| l.weight).collect();
+        assert_eq!(
+            weights,
+            [1.0],
+            "nothing to share: the rule at full strength"
+        );
+        // The same stack, asked again without its glint, is not answered from the cache.
+        assert!(
+            cit.glint(&overridden(new("stick"), true), Hand::Main, 0, false)
+                .is_none()
+        );
+    }
+
+    #[test]
+    fn a_rule_left_out_of_the_glints_matches_nothing() {
+        let mut cit = rules(&[
+            ("broken", "type=enchantment\nitems=diamond_sword\nweight=1"),
+            ("shown", "type=enchantment"),
+        ]);
+        let sword = enchanted("diamond_sword", &[("sharpness", 1)]);
+        let layers = |cit: &CitRules| -> Vec<String> {
+            let glint = glint(cit, &sword, false).unwrap();
+            let stems = glint
+                .layers
+                .iter()
+                .map(|l| stem(cit, Some(l.rule)).unwrap());
+            stems.map(str::to_owned).collect()
+        };
+        // The heavier rule wins the layer, until its texture is missing.
+        assert_eq!(layers(&cit), ["broken"]);
+        let broken = (0..cit.rules.len())
+            .find(|&i| stem(&cit, Some(i)) == Some("broken"))
+            .unwrap();
+        cit.keep_glints(|i| i != broken);
+        assert_eq!(layers(&cit), ["shown"]);
+        assert_eq!(cit.enchantments(&sword, Hand::Main, 0).len(), 1);
+        // None left: vanilla's glint stays.
+        cit.keep_glints(|_| false);
+        assert!(glint(&cit, &sword, false).is_none());
+    }
+
+    #[test]
+    fn an_off_hand_layer_draws_only_in_the_off_hand() {
+        let cit = rules(&[
+            ("left", "type=enchantment\nlayer=1\nhand=off"),
+            ("both", "type=enchantment"),
+        ]);
+        let sword = enchanted("diamond_sword", &[("sharpness", 1)]);
+        let layers = |hand| -> Vec<&str> {
+            let glint = cit.glint(&sword, hand, 0, true).unwrap();
+            glint
+                .layers
+                .iter()
+                .map(|l| stem(&cit, Some(l.rule)).unwrap())
+                .collect()
+        };
+        assert_eq!(layers(Hand::Off), ["both", "left"]);
+        // Asked in this order, a cache keyed without the hand would answer as for the off hand.
+        assert_eq!(layers(Hand::Main), ["both"]);
+    }
+}

crates/horizon-client-render/src/pack_formats/cit_glint.rs

@@ -0,0 +1,301 @@
+//! OptiFine's Custom Item Textures' enchantment glints (`type=enchantment`): which of a stack's
+//! matching rules draw, in which order and how strongly, and whether vanilla's glint still draws
+//! under them ([`crate::cit_glint::StackGlint`]). The pack's `cit.properties` (`Global`) says how
+//! layers share an item.
+//!
+//! Written from OptiFine's `cit.properties` doc and CIT Resewn's (MIT) `TypeEnchantment` of
+//! before its 1.21.11 port, which implemented `method`, `cap` and `fade`: the sums and the
+//! cycle's fading follow it, except where noted.
+
+use super::cit::read_properties;
+use crate::cit_glint::{GlintLayer, StackGlint};
+use horizon_optifine::cit::{Global, Method, Rule};
+use std::path::Path;
+
+/// The pack's global `cit.properties` under the overlay resource root: the first of
+/// `Global::PATHS` that exists, else the defaults.
+pub fn load_global(root: &Path) -> Global {
+    Global::PATHS
+        .iter()
+        .find_map(|path| read_properties(&root.join(path)))
+        .map(|props| Global::parse(&props))
+        .unwrap_or_default()
+}
+
+/// A stack's glint: the layers among `matched` (its matching enchantment rules, in priority
+/// order, as `CitRules::enchantments` gives them) that draw, for a stack with `enchantments`
+/// (`ItemStack::crafting_enchantments`).
+pub fn stack_glint(
+    rules: &[Rule],
+    matched: &[usize],
+    enchantments: &[(impl AsRef<str>, u32)],
+    global: &Global,
+) -> StackGlint {
+    // The highest priority rule of each layer.
+    let mut layers: Vec<usize> = Vec::new();
+    for &i in matched {
+        let layer = rules[i].glint.layer;
+        if !layers.iter().any(|&j| rules[j].glint.layer == layer) {
+            layers.push(i);
+        }
+    }
+    layers.sort_by_key(|&i| rules[i].glint.layer);
+    let cycle = global.method == Method::Cycle;
+    // OptiFine's doc: `cap` is for `average` and `layered`, and keeps the topmost layers.
+    // `none`, which OptiFine lacks, is capped too, as CIT Resewn caps every method (it keeps
+    // the bottom layers, though, and caps cycles as well).
+    if let Some(cap) = global.cap.filter(|_| !cycle) {
+        let cap = usize::try_from(cap).unwrap_or(usize::MAX);
+        layers = layers.split_off(layers.len().saturating_sub(cap));
+    }
+    // CIT Resewn: any layer left asking for vanilla's glint keeps it, and the global
+    // `useGlint=false` removes it everywhere, as OptiFine's doc says too. `cap=0` leaves no
+    // custom layer, and vanilla's glint only if the pack's `useGlint` allows it.
+    let vanilla =
+        global.use_glint && (layers.is_empty() || layers.iter().any(|&i| rules[i].glint.use_glint));
+    // CIT Resewn: shares are against every enchantment of the stack, not only those the
+    // layers name.
+    let levels = enchantments.iter().map(|(_, level)| *level as f32);
+    let total = match global.method {
+        Method::Average => levels.sum::<f32>(),
+        Method::Layered => levels.fold(0.0, f32::max),
+        Method::None | Method::Cycle => 0.0,
+    };
+    let shared = matches!(global.method, Method::Average | Method::Layered);
+    let layers = layers
+        .into_iter()
+        .map(|i| {
+            let rule = &rules[i];
+            let named = &rule.enchantments;
+            let weight = if !shared || named.is_empty() {
+                1.0
+            } else {
+                // The highest level among the enchantments the rule names whose level also
+                // passes its `enchantmentLevels` (CIT Resewn takes the first named one the
+                // stack has, whatever its level).
+                let in_range = |level: u32| {
+                    let level = i32::try_from(level).unwrap_or(i32::MAX);
+                    rule.enchantment_levels
+                        .as_ref()
+                        .is_none_or(|r| r.contains(level))
+                };
+                let level = enchantments
+                    .iter()
+                    .filter(|(id, level)| {
+                        let id: &str = id.as_ref();
+                        named.iter().any(|n| n == id) && in_range(*level)
+                    })
+                    .map(|(_, level)| *level as f32)
+                    .fold(0.0, f32::max);
+                if total > 0.0 { level / total } else { 0.0 }
+            };
+            GlintLayer::new(i, weight, rule.glint.duration)
+        })
+        .collect();
+    StackGlint::from_parts(layers, vanilla, cycle.then_some(global.fade))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use horizon_optifine::Properties;
+
+    const DIR: &str = "assets/minecraft/optifine/cit";
+
+    /// An enchantment rule named `name` with `text` after `type` and `texture`.
+    fn rule(name: &str, text: &str) -> Rule {
+        let text = format!("type=enchantment\ntexture=glint\n{text}");
+        let path = format!("{DIR}/{name}.properties");
+        Rule::parse(&path, &Properties::parse_equals_first(&text), |_| true).unwrap()
+    }
+
+    fn global(text: &str) -> Global {
+        Global::parse(&Properties::parse_equals_first(text))
+    }
+
+    fn rules_of(layers: &StackGlint) -> Vec<usize> {
+        layers.layers.iter().map(|l| l.rule).collect()
+    }
+
+    const SWORD: [(&str, u32); 2] = [("minecraft:sharpness", 3), ("minecraft:unbreaking", 1)];
+
+    #[test]
+    fn one_rule_per_layer_bottom_first() {
+        let rules = [
+            rule("a", "layer=2"),
+            rule("b", "layer=0"),
+            rule("c", "layer=2"),
+            rule("d", "layer=-1"),
+        ];
+        // Priority order a, b, c, d: c loses layer 2 to a.
+        let g = stack_glint(&rules, &[0, 1, 2, 3], &SWORD, &Global::default());
+        assert_eq!(rules_of(&g), [3, 1, 0]);
+        let g = stack_glint(&rules, &[2, 0], &SWORD, &Global::default());
+        assert_eq!(rules_of(&g), [2]);
+    }
+
+    #[test]
+    fn average_and_layered_shares() {
+        let rules = [
+            rule("sharp", "enchantments=sharpness smite"),
+            rule("unb", "layer=1\nenchantments=unbreaking"),
+            rule("any", "layer=2"),
+            rule("fire", "layer=3\nenchantments=fire_aspect"),
+        ];
+        let weights = |method: &str| {
+            let g = stack_glint(&rules, &[0, 1, 2, 3], &SWORD, &global(method));
+            g.layers.iter().map(|l| l.weight).collect::<Vec<_>>()
+        };
+        // Sharpness III and Unbreaking I: 3 / 4 and 1 / 4; against the highest, 3 / 3 and 1 / 3.
+        // A rule naming no enchantment is at full strength, one the stack lacks at none.
+        assert_eq!(weights("method=average"), [0.75, 0.25, 1.0, 0.0]);
+        assert_eq!(weights("method=layered"), [1.0, 1.0 / 3.0, 1.0, 0.0]);
+        assert_eq!(weights("method=cycle"), [1.0; 4]);
+        assert_eq!(weights("method=none"), [1.0; 4]);
+    }
+
+    #[test]
+    fn the_level_is_one_the_rules_levels_allow() {
+        let rules = [rule(
+            "holy",
+            "enchantments=sharpness smite\nenchantmentLevels=1-2",
+        )];
+        // Sharpness V is out of range, so Smite I sets the share: 1 / 5 of the highest level.
+        let stack = [("minecraft:sharpness", 5), ("minecraft:smite", 1)];
+        let g = stack_glint(&rules, &[0], &stack, &global("method=layered"));
+        assert_eq!(g.layers[0].weight, 1.0 / 5.0);
+    }
+
+    #[test]
+    fn cap_keeps_the_topmost_layers() {
+        let rules = [
+            rule("a", "layer=0"),
+            rule("b", "layer=1"),
+            rule("c", "layer=2"),
+        ];
+        let g = stack_glint(&rules, &[0, 1, 2], &SWORD, &global("cap=2"));
+        assert_eq!(rules_of(&g), [1, 2]);
+        let g = stack_glint(&rules, &[0, 1, 2], &SWORD, &global("cap=0"));
+        assert!(g.is_empty());
+        let g = stack_glint(&rules, &[0, 1, 2], &SWORD, &global("cap=1\nmethod=none"));
+        assert_eq!(rules_of(&g), [2]);
+        // Cycles show every layer in turn.
+        let g = stack_glint(&rules, &[0, 1, 2], &SWORD, &global("cap=1\nmethod=cycle"));
+        assert_eq!(rules_of(&g), [0, 1, 2]);
+    }
+
+    #[test]
+    fn vanilla_glint() {
+        let plain = rule("plain", "");
+        let keep = rule("keep", "layer=1\nuseGlint=true");
+        let rules = [plain, keep];
+        let vanilla = |matched: &[usize], text: &str| {
+            stack_glint(&rules, matched, &SWORD, &global(text)).vanilla
+        };
+        assert!(vanilla(&[], ""), "no rule: vanilla's glint");
+        assert!(!vanilla(&[0], ""), "a rule replaces it");
+        assert!(vanilla(&[0, 1], ""), "unless one keeps it");
+        assert!(!vanilla(&[], "useGlint=false"));
+        assert!(!vanilla(&[1], "useGlint=false"), "the pack's word is final");
+        // Only the layers `cap` keeps count.
+        let rules = [rule("keep", "useGlint=true"), rule("top", "layer=1")];
+        let g = stack_glint(&rules, &[0, 1], &SWORD, &global("cap=1"));
+        assert!(!g.vanilla);
+        let g = stack_glint(&rules, &[0, 1], &SWORD, &global("cap=0"));
+        assert!(g.is_empty() && g.vanilla);
+        let g = stack_glint(&rules, &[0, 1], &SWORD, &global("cap=0\nuseGlint=false"));
+        assert!(!g.vanilla);
+    }
+
+    #[test]
+    fn cycles_take_turns_and_fade() {
+        let rules = [
+            rule("a", "duration=2"),
+            rule("b", "layer=1\nduration=1"),
+            rule("c", "layer=2\nduration=1"),
+        ];
+        let g = stack_glint(
+            &rules,
+            &[0, 1, 2],
+            &SWORD,
+            &global("method=cycle\nfade=0.5"),
+        );
+        // a 0-2, a→b 2-2.5, b 2.5-3.5, b→c 3.5-4, c 4-5, c→a 5-5.5, then again.
+        let at = |t: f64| [0, 1, 2].map(|i| g.intensity(i, t));
+        assert_eq!(at(1.0), [1.0, 0.0, 0.0]);
+        assert_eq!(at(2.125), [0.75, 0.25, 0.0]);
+        assert_eq!(at(3.0), [0.0, 1.0, 0.0]);
+        assert_eq!(at(3.75), [0.0, 0.5, 0.5]);
+        assert_eq!(at(4.5), [0.0, 0.0, 1.0]);
+        assert_eq!(at(5.25), [0.5, 0.0, 0.5]);
+        assert_eq!(at(5.5 + 3.0), [0.0, 1.0, 0.0]);
+        // One layer always shows.
+        let one = stack_glint(&rules, &[1], &SWORD, &global("method=cycle"));
+        assert_eq!(one.intensity(0, 0.7), 1.0);
+    }
+
+    #[test]
+    fn a_cycle_always_shows_a_whole_layer() {
+        let rules = [
+            rule("a", "duration=0.1"),
+            rule("b", "layer=1\nduration=0.7"),
+            rule("c", "layer=2\nduration=0.2"),
+        ];
+        let g = stack_glint(
+            &rules,
+            &[0, 1, 2],
+            &SWORD,
+            &global("method=cycle\nfade=0.3"),
+        );
+        // Every millisecond of the first two seconds, and just under a period, the last fade's
+        // end. (Rounding has not been seen to leave time past it; the last fade's clamp is
+        // defensive.)
+        let period: f64 = [0.1f32, 0.7, 0.2]
+            .map(|d| f64::from(d) + f64::from(0.3f32))
+            .iter()
+            .sum();
+        let last = f64::from_bits(period.to_bits() - 1);
+        for t in (0..2000_i32)
+            .map(|i| f64::from(i) * 0.001)
+            .chain([last, period + last])
+        {
+            let sum: f32 = (0..3).map(|i| g.intensity(i, t)).sum();
+            assert!((sum - 1.0).abs() < 1e-5, "{sum} at {t}");
+        }
+        // No time at all: the bottom layer alone, never NaN.
+        let still = [rule("a", "duration=0"), rule("b", "layer=1\nduration=0")];
+        let g = stack_glint(&still, &[0, 1], &SWORD, &global("method=cycle\nfade=0"));
+        for t in [0.0, 0.5, 7.25] {
+            assert_eq!([0, 1].map(|i| g.intensity(i, t)), [1.0, 0.0]);
+        }
+    }
+
+    #[test]
+    fn the_first_global_file_wins() {
+        let root = std::env::temp_dir().join(format!("horizon-cit-glint-{}", std::process::id()));
+        let _ = std::fs::remove_dir_all(&root);
+        assert_eq!(load_global(&root), Global::default());
+        let write = |path: &str, text: &[u8]| {
+            let file = root.join(path);
+            std::fs::create_dir_all(file.parent().unwrap()).unwrap();
+            std::fs::write(file, text).unwrap();
+        };
+        // Saved as Latin-1 (`é` is not UTF-8 alone), in the OptiFine doc's `cit/` folder.
+        write(
+            "assets/minecraft/optifine/cit/cit.properties",
+            b"# caf\xE9\nmethod=cycle",
+        );
+        assert_eq!(load_global(&root).method, Method::Cycle);
+        write("assets/minecraft/mcpatcher/cit.properties", b"method=none");
+        assert_eq!(load_global(&root).method, Method::Cycle);
+        write(
+            "assets/minecraft/optifine/cit.properties",
+            b"method=layered",
+        );
+        assert_eq!(load_global(&root).method, Method::Layered);
+        write("assets/minecraft/citresewn/cit.properties", b"cap=1");
+        let g = load_global(&root);
+        let _ = std::fs::remove_dir_all(&root);
+        assert_eq!((g.method, g.cap), (Method::Average, Some(1)));
+    }
+}

crates/horizon-client-render/src/pack_formats/colors.rs

@@ -7,6 +7,14 @@ use horizon_polytone::colors::PackColors;
 use crate::block_entity_render::DYES;
 use crate::pack_palette::{self, Environment};
 
+fn fluid(fog: horizon_polytone::colors::FluidFog) -> pack_palette::FluidFog {
+    pack_palette::FluidFog {
+        color: fog.color,
+        radius: fog.radius,
+        fade: fog.fade,
+    }
+}
+
 /// The colours of every namespace's file under the pack overlay at `root`.
 pub fn read(root: &Path) -> pack_palette::PackColors {
     let colors = PackColors::read(root);
@@ -29,6 +37,10 @@ pub fn read(root: &Path) -> pack_palette::PackColors {
             water_fog_brightening_time: env.water_fog_brightening_time,
             horizon_height: env.horizon_height,
         },
+        fluid_fog: pack_palette::FluidFogs {
+            water: colors.fluid_fog.water.map(fluid),
+            lava: colors.fluid_fog.lava.map(fluid),
+        },
     }
 }
 

crates/horizon-client-render/src/pack_formats/connected.rs

@@ -0,0 +1,136 @@
+//! OptiFine's and Fusion's connected textures as the mesher draws them
+//! ([`crate::connected::ConnectedTextures`]): a Fusion face first, then OptiFine's rules.
+
+use std::path::Path;
+use std::sync::Arc;
+
+use horizon_optifine::ctm::connect::{Axes, Face};
+use horizon_world::registry::{BlockRegistry, BlockStateId};
+
+use super::ctm::ConnectedTextures as Ctm;
+use super::fusion::FusionTextures;
+use crate::chunk::Chunk;
+use crate::connected::{self as engine, Connected, ConnectedTextures, Overlay, Pick};
+use crate::mesher::{MeshScratch, Mesher, SectionMesh};
+use crate::models::StateModels;
+use crate::sprites::Sprites;
+
+/// A pack's Fusion and OptiFine connected textures.
+pub struct Rules {
+    ctm: Ctm,
+    fusion: FusionTextures,
+}
+
+/// The connected textures under `root`: Fusion's models' tiles, native mods' sprites, then
+/// OptiFine's rules' tiles go into `sprites`, in that order. `None` without either format's files.
+pub fn load(
+    root: &Path,
+    registry: &BlockRegistry,
+    sprites: &mut Sprites,
+    models: &mut StateModels,
+    native_mods: &mut dyn FnMut(&mut Sprites),
+) -> Option<Connected> {
+    let fusion = {
+        let _step = crate::spans::startup::step("core.fusion");
+        FusionTextures::load(root, registry, sprites, models)
+    };
+    native_mods(sprites);
+    // A side's sprite, for rules that connect by tile: the first quad facing it.
+    let catalog = &*models;
+    let mut found = Vec::new();
+    let ctm = Ctm::load(
+        root,
+        registry,
+        sprites,
+        |state: BlockStateId, face: Face| {
+            let side = horizon_assets::model::Direction::ALL[face as usize];
+            catalog
+                .models_at(
+                    state,
+                    horizon_core::position::BlockPos::new(0, 0, 0),
+                    &mut found,
+                )
+                .ok()?;
+            found
+                .iter()
+                .flat_map(|m| &m.faces)
+                .find(|f| f.quad.facing == side)
+                .map(|f| f.layer)
+        },
+    );
+    let rules = Rules { ctm, fusion };
+    (!rules.is_empty()).then(|| Connected {
+        rules: Arc::new(rules),
+        mesh,
+    })
+}
+
+/// The mesher on [`Rules`].
+fn mesh(
+    mesher: &mut Mesher<'_>,
+    rules: &(dyn std::any::Any + Send + Sync),
+    region: &[[Option<&Chunk>; 3]; 3],
+    sy: i32,
+    out: SectionMesh,
+    scratch: &mut MeshScratch,
+) -> SectionMesh {
+    let rules = rules
+        .downcast_ref::<Rules>()
+        .expect("the connected textures this format loaded");
+    mesher.mesh_with(rules, region, sy, out, scratch)
+}
+
+impl ConnectedTextures for Rules {
+    fn is_empty(&self) -> bool {
+        self.ctm.is_empty() && self.fusion.is_empty()
+    }
+
+    fn stacked_pane_hides(&self, state: u32, other: u32, centre: [f32; 2]) -> bool {
+        !self.ctm.is_empty() && self.ctm.stacked_pane_hides(state, other, centre)
+    }
+
+    fn pick<'b>(
+        &self,
+        face: &engine::Face,
+        neighbour: impl Fn([i32; 3]) -> u32,
+        covers: impl Fn(u32) -> bool,
+        biome: impl Fn() -> Option<&'b str>,
+        mut overlay: impl FnMut(Overlay),
+    ) -> Pick {
+        let side = Face::ALL[usize::from(face.facing)];
+        let fused = face.rule.and_then(|rule| {
+            self.fusion.pick(
+                rule,
+                face.state,
+                side,
+                face.tint_index,
+                &neighbour,
+                covers,
+                &mut overlay,
+            )
+        });
+        if let Some(pick) = fused {
+            pick
+        } else if self.ctm.is_empty() {
+            Pick::Keep
+        } else {
+            self.ctm.pick(
+                face.state,
+                face.layer,
+                side,
+                face.pos,
+                &neighbour,
+                biome,
+                // A pane's tiles are drawn with the cube's UVs, so that is its texture.
+                || {
+                    if face.pane {
+                        Some(Axes::cube(side))
+                    } else {
+                        Axes::texture(face.positions, face.uv)
+                    }
+                },
+                &mut overlay,
+            )
+        }
+    }
+}

crates/horizon-client-render/src/pack_formats/entity_textures.rs

@@ -0,0 +1,88 @@
+//! OptiFine's random entity textures and ETF's blinking and emissive textures
+//! (`horizon_optifine::{random_textures, blink, emissive}`) as the engine's
+//! [`crate::entity_textures`] tables.
+
+use crate::entity_textures::{
+    self as engine, Blink, Blinks, Emissive, EntityTextures, Entry, RandomTextures,
+};
+use horizon_optifine::random::{self, Rules};
+use std::path::Path;
+
+/// The pack's variants, blinks and emissive overlays under the overlay resource root.
+pub fn load(root: &Path) -> EntityTextures {
+    let random = horizon_optifine::random_textures::RandomTextures::scan(root);
+    let blinks = horizon_optifine::blink::Blinks::scan(root, &random);
+    let mut emissive = horizon_optifine::emissive::Emissive::scan(root, &random);
+    emissive.pair_beside(root, blinks.files());
+    let files = random
+        .files()
+        .map(|(f, n)| (f.to_owned(), n.to_owned()))
+        .collect();
+    let generation = random.generation();
+    let (entries, rules) = random.into_parts();
+    let entries = entries
+        .into_iter()
+        .map(|(texture, entry)| {
+            let variants = entry
+                .variant_names()
+                .map(|(n, name)| (n, name.to_owned()))
+                .collect();
+            let rules = entry.rules;
+            (texture, Entry { rules, variants })
+        })
+        .collect();
+    let (blinks, blink_files) = blinks.into_parts();
+    let blinks = blinks
+        .into_iter()
+        .map(|(texture, b)| {
+            let blink = Blink {
+                shut: b.shut,
+                half: b.half,
+                length: b.length,
+                frequency: b.frequency,
+            };
+            (texture, blink)
+        })
+        .collect();
+    let (suffix, overlays, overlay_files) = emissive.into_parts();
+    EntityTextures {
+        random: RandomTextures::new(entries, files, Box::new(Variants(rules)), generation),
+        blinks: Blinks::new(blinks, blink_files),
+        emissive: Emissive::new(suffix, overlays, overlay_files),
+    }
+}
+
+/// The rule files of a scan.
+struct Variants(Vec<Rules>);
+
+impl engine::VariantRules for Variants {
+    fn matching(&self, rules: usize, facts: &engine::Facts, seed: i32) -> Option<u32> {
+        let blocks: Vec<random::Block> = facts
+            .blocks
+            .iter()
+            .map(|b| random::Block {
+                id: b.id,
+                states: b.states,
+            })
+            .collect();
+        let facts = random::Facts {
+            biome: facts.biome,
+            y: facts.y,
+            blocks: &blocks,
+            name: facts.name,
+            profession: facts.profession,
+            color: facts.color,
+            baby: facts.baby,
+            health: facts.health,
+            moon_phase: facts.moon_phase,
+            day_time: facts.day_time,
+            weather: facts.weather.map(|w| match w {
+                engine::Weather::Clear => random::Weather::Clear,
+                engine::Weather::Rain => random::Weather::Rain,
+                engine::Weather::Thunder => random::Weather::Thunder,
+            }),
+            size: facts.size,
+        };
+        self.0.get(rules)?.matching(&facts, seed)
+    }
+}

crates/horizon-client-render/src/pack_formats/fusion.rs

@@ -273,6 +273,10 @@ fn sheet(
 }
 
 impl FusionTextures {
+    pub fn is_empty(&self) -> bool {
+        self.rules.is_empty()
+    }
+
     /// The connecting textures under `root`: the tiles of those `fusion:connecting` models
     /// draw are inserted into `sprites` (before it finishes), and each face in `catalog` that
     /// shows one gets its rule.

crates/horizon-client-render/src/pack_formats/mod.rs

@@ -3,9 +3,17 @@
 //! crate until the platform's executable installs it: it uses only the crate's public API, so it
 //! moves to a platform crate unchanged, and nothing else in the crate names it.
 
+pub(crate) mod block_entity_cem;
+pub mod cit;
+mod cit_glint;
 mod colors;
+mod connected;
+mod ctm;
 mod custom_sky;
+mod entity_textures;
+mod fusion;
 mod item_bars;
+mod pack_options;
 
 use std::path::Path;
 use std::sync::Arc;
@@ -20,11 +28,63 @@ impl PackFormats for Formats {
         Some(colors::read(root))
     }
 
+    fn connected_textures(
+        &self,
+        root: &Path,
+        registry: &horizon_world::registry::BlockRegistry,
+        sprites: &mut crate::sprites::Sprites,
+        models: &mut crate::models::StateModels,
+        native_mods: &mut dyn FnMut(&mut crate::sprites::Sprites),
+    ) -> Option<crate::connected::Connected> {
+        connected::load(root, registry, sprites, models, native_mods)
+    }
+
+    fn emissive_suffix(&self, root: &Path) -> Option<String> {
+        Some(horizon_optifine::emissive::suffix(root))
+    }
+
+    fn item_textures(&self, root: &Path) -> Option<crate::cit::CitRules> {
+        Some(cit::load(root))
+    }
+
+    fn entity_textures(&self, root: &Path) -> Option<crate::entity_textures::EntityTextures> {
+        Some(entity_textures::load(root))
+    }
+
+    fn block_entity_models(
+        &self,
+        root: &Path,
+        vanilla: &std::collections::HashMap<&'static str, crate::block_entity_render::ModelPart>,
+    ) -> Option<crate::pack_hooks::Reshaped> {
+        block_entity_cem::reshape(root, vanilla)
+    }
+
     fn custom_sky(&self, root: &Path) -> Option<Arc<dyn crate::custom_sky::SkyLayers>> {
         let sky = custom_sky::CustomSky::load(root);
         (!sky.is_empty()).then(|| Arc::new(sky) as _)
     }
 
+    fn pack_options(&self, source: &crate::packs::Source) -> Option<horizon_pack_options::Configs> {
+        Some(pack_options::read(source))
+    }
+
+    fn overlay_active(
+        &self,
+        entry: &serde_json::Value,
+        options: &horizon_pack_options::Configs,
+        formats_apply: bool,
+    ) -> bool {
+        horizon_polytone::pack::overlay_active(entry, options, formats_apply)
+    }
+
+    fn sounds_without_unmet(
+        &self,
+        text: &[u8],
+        options: &horizon_pack_options::Configs,
+    ) -> Option<Vec<u8>> {
+        horizon_polytone::pack::sounds_without_unmet(text, options)
+    }
+
     fn item_bars(&self, root: &Path) -> Option<Arc<dyn crate::pack_palette::ItemBars>> {
         item_bars::read(root)
     }

crates/horizon-client-render/src/pack_formats/pack_options.rs

@@ -0,0 +1,62 @@
+//! Polytone's pack options (wiki "Polytone Configs") and the `polytone_condition`s that read
+//! them, on pack overlays and on `sounds.json` events.
+
+use crate::packs::Source;
+use crate::zip::Zip;
+use horizon_pack_options::Configs;
+use horizon_polytone::pack::add_entry;
+use std::fs;
+
+/// A pack's Polytone config entries (`assets/<namespace>/polytone/config_entries/<name>.json`,
+/// in the pack's base, not its overlays) at their default values.
+pub fn read(source: &Source) -> Configs {
+    let mut configs = Configs::default();
+    let id_of = |name: &str| -> Option<String> {
+        let rest = name.strip_prefix("assets/")?;
+        let (namespace, rest) = rest.split_once('/')?;
+        let entry = rest
+            .strip_prefix("polytone/config_entries/")?
+            .strip_suffix(".json")?;
+        Some(format!("{namespace}:{entry}"))
+    };
+    match source {
+        Source::Dir(d) => {
+            let Ok(namespaces) = fs::read_dir(d.join("assets")) else {
+                return configs;
+            };
+            for namespace in namespaces.flatten() {
+                let folder = namespace.path().join("polytone/config_entries");
+                for file in fs::read_dir(&folder).into_iter().flatten().flatten() {
+                    let name = format!(
+                        "assets/{}/polytone/config_entries/{}",
+                        namespace.file_name().to_string_lossy(),
+                        file.file_name().to_string_lossy()
+                    );
+                    if let (Some(id), Ok(bytes)) = (id_of(&name), fs::read(file.path()))
+                        && let Ok(json) = serde_json::from_slice(&bytes)
+                    {
+                        add_entry(&mut configs, id, &json);
+                    }
+                }
+            }
+        }
+        Source::Zip(z) => {
+            let Ok(zip) = Zip::open(z) else {
+                return configs;
+            };
+            let names: Vec<String> = zip
+                .names()
+                .filter(|n| id_of(n).is_some())
+                .map(str::to_owned)
+                .collect();
+            for name in names {
+                if let (Some(id), Ok(bytes)) = (id_of(&name), zip.read(&name))
+                    && let Ok(json) = serde_json::from_slice(&bytes)
+                {
+                    add_entry(&mut configs, id, &json);
+                }
+            }
+        }
+    }
+    configs
+}

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

@@ -15,17 +15,93 @@ pub trait PackFormats: Send + Sync {
         None
     }
 
+    /// The name ending of the overlay's emissive textures (`stone_e.png` beside `stone.png`),
+    /// if its format has them.
+    fn emissive_suffix(&self, _root: &Path) -> Option<String> {
+        None
+    }
+
+    /// The overlay's connected textures: their tiles go into `sprites` (before it finishes), and
+    /// baked faces they draw on may get a rule (`crate::models::BakedFace::fusion`).
+    /// `native_mods` loads native mods' own sprites: call it after the tiles that go before them.
+    fn connected_textures(
+        &self,
+        _root: &Path,
+        _registry: &horizon_world::registry::BlockRegistry,
+        _sprites: &mut crate::sprites::Sprites,
+        _models: &mut crate::models::StateModels,
+        _native_mods: &mut dyn FnMut(&mut crate::sprites::Sprites),
+    ) -> Option<crate::connected::Connected> {
+        None
+    }
+
+    /// The overlay's custom item texture rules and their matcher.
+    fn item_textures(&self, _root: &Path) -> Option<crate::cit::CitRules> {
+        None
+    }
+
+    /// The overlay's entity texture variants, blinks and emissive overlays.
+    fn entity_textures(&self, _root: &Path) -> Option<crate::entity_textures::EntityTextures> {
+        None
+    }
+
+    /// The block entity models the overlay reshapes over `vanilla`'s, with their textures;
+    /// `None` when it reshapes none.
+    fn block_entity_models(
+        &self,
+        _root: &Path,
+        _vanilla: &std::collections::HashMap<&'static str, crate::block_entity_render::ModelPart>,
+    ) -> Option<Reshaped> {
+        None
+    }
+
     /// The sky layers the overlay draws over the vanilla sky, if it has any.
     fn custom_sky(&self, _root: &Path) -> Option<Arc<dyn crate::custom_sky::SkyLayers>> {
         None
     }
 
+    /// The options the pack (its base, not its overlays) declares, at their defaults.
+    fn pack_options(
+        &self,
+        _source: &crate::packs::Source,
+    ) -> Option<horizon_pack_options::Configs> {
+        None
+    }
+
+    /// Whether an `overlays.entries[]` item of `pack.mcmeta` is active, given the pack's options;
+    /// `formats_apply` is vanilla's answer from its `formats`.
+    fn overlay_active(
+        &self,
+        _entry: &serde_json::Value,
+        _options: &horizon_pack_options::Configs,
+        formats_apply: bool,
+    ) -> bool {
+        formats_apply
+    }
+
+    /// A pack's `sounds.json` without the events its options turn off; `None` when it keeps
+    /// them all.
+    fn sounds_without_unmet(
+        &self,
+        _text: &[u8],
+        _options: &horizon_pack_options::Configs,
+    ) -> Option<Vec<u8>> {
+        None
+    }
+
     /// The durability bar colours the overlay sets by item, if any.
     fn item_bars(&self, _root: &Path) -> Option<Arc<dyn crate::pack_palette::ItemBars>> {
         None
     }
 }
 
+/// Every block entity model, reshaped by a pack or vanilla's, and the atlas names of the
+/// pack's textures by model ([`PackFormats::block_entity_models`]).
+pub type Reshaped = (
+    std::collections::HashMap<&'static str, crate::block_entity_render::ModelPart>,
+    std::collections::HashMap<&'static str, String>,
+);
+
 /// No format beyond vanilla's.
 struct Vanilla;
 

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

@@ -12,7 +12,7 @@ use crate::{
     text::Text,
     ui,
 };
-use horizon_polytone::pack::{ConfigKind, ConfigValue, Configs};
+use horizon_pack_options::{ConfigKind, ConfigValue, Configs};
 
 /// What a click asks of the options screen.
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
@@ -481,17 +481,36 @@ impl PackOptionsUi {
 mod tests {
     use super::*;
 
+    use horizon_pack_options::ConfigEntry;
+
+    fn slider(default: f64) -> ConfigEntry {
+        let kind = ConfigKind::Number {
+            min: 0.0,
+            max: 1.0,
+            step: 0.1,
+        };
+        ConfigEntry::new(kind, ConfigValue::Number(default))
+    }
+
+    fn in_section(entry: ConfigEntry, section: &str, order: i64) -> ConfigEntry {
+        ConfigEntry {
+            section: Some(section.into()),
+            section_order: Some(order),
+            ..entry
+        }
+    }
+
     fn configs() -> Configs {
         let mut c = Configs::default();
-        c.add_entry(
-            "p:fog".into(),
-            &serde_json::json!({"default_value": 0.5, "section": "sky", "section_order": 2}),
-        );
-        c.add_entry("p:rain".into(), &serde_json::json!({"default_value": "drops", "allowed_values": ["drops", "streaks"], "section": "weather", "section_order": 1}));
-        c.add_entry(
-            "p:birds".into(),
-            &serde_json::json!({"default_value": true}),
+        c.insert("p:fog".into(), in_section(slider(0.5), "sky", 2));
+        let allowed = vec!["drops".into(), "streaks".into()];
+        let rain = ConfigEntry::new(
+            ConfigKind::Text { allowed },
+            ConfigValue::Text("drops".into()),
         );
+        c.insert("p:rain".into(), in_section(rain, "weather", 1));
+        let birds = ConfigEntry::new(ConfigKind::Bool, ConfigValue::Bool(true));
+        c.insert("p:birds".into(), birds);
         c
     }
 
@@ -537,9 +556,16 @@ mod tests {
     #[test]
     fn the_presets_row_cycles_the_pack_wide_presets_and_shows_custom_otherwise() {
         let mut c = Configs::default();
-        let entry = |default: f64, fast: f64, pretty: f64| serde_json::json!({"default_value": default, "presets": {"fast": fast, "pretty": pretty}});
-        c.add_entry("p:fog".into(), &entry(0.5, 0.0, 1.0));
-        c.add_entry("p:dust".into(), &entry(0.5, 0.0, 0.8));
+        let entry = |fast: f64, pretty: f64| ConfigEntry {
+            presets: [
+                ("fast".into(), ConfigValue::Number(fast)),
+                ("pretty".into(), ConfigValue::Number(pretty)),
+            ]
+            .into(),
+            ..slider(0.5)
+        };
+        c.insert("p:fog".into(), entry(0.0, 1.0));
+        c.insert("p:dust".into(), entry(0.0, 0.8));
         let mut ui = PackOptionsUi::open(c);
         // The defaults are no preset.
         assert_eq!(ui.current_preset(), None);

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

@@ -59,6 +59,24 @@ pub struct PackColors {
     pub xp_bar: [Option<u32>; 2],
     /// The effect fogs' settings: the fog reads them every frame.
     pub env: Environment,
+    /// The fog the packs' fluid modifiers give water and lava.
+    pub fluid_fog: FluidFogs,
+}
+
+/// A fluid modifier's fog: a flat colour (RGB), and the fog's radius and fade multipliers (1 is
+/// vanilla's).
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub struct FluidFog {
+    pub color: Option<u32>,
+    pub radius: f32,
+    pub fade: f32,
+}
+
+/// The fog the packs' fluid modifiers give water and lava.
+#[derive(Clone, Copy, Debug, Default, PartialEq)]
+pub struct FluidFogs {
+    pub water: Option<FluidFog>,
+    pub lava: Option<FluidFog>,
 }
 
 impl Default for PackColors {
@@ -72,6 +90,7 @@ impl Default for PackColors {
             entity_shadows: true,
             xp_bar: [None; 2],
             env: Environment::default(),
+            fluid_fog: FluidFogs::default(),
         }
     }
 }

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

@@ -38,7 +38,7 @@ pub struct Pack {
     /// Polytone `polytone_condition` turns on.
     pub overlays: Vec<String>,
     /// The values of the pack's Polytone config entries.
-    pub polytone_configs: horizon_polytone::pack::Configs,
+    pub polytone_configs: Configs,
     /// `filter.block` entries (namespace and path patterns) hiding resources
     /// of the packs below this one.
     pub filter: Vec<Filter>,
@@ -419,12 +419,13 @@ fn overlay_applies(entry: &serde_json::Value) -> bool {
         _ => false,
     }
 }
-fn overlays_of(meta: &serde_json::Value, configs: &horizon_polytone::pack::Configs) -> Vec<String> {
+fn overlays_of(meta: &serde_json::Value, configs: &Configs) -> Vec<String> {
+    let formats = crate::pack_hooks::formats();
     meta["overlays"]["entries"]
         .as_array()
         .into_iter()
         .flatten()
-        .filter(|e| horizon_polytone::pack::overlay_active(e, configs, overlay_applies(e)))
+        .filter(|e| formats.overlay_active(e, configs, overlay_applies(e)))
         .filter_map(|e| e["directory"].as_str().map(str::to_owned))
         // OverlayMetadataSection's DIR_VALIDATOR: one folder of the pack, `[-_a-zA-Z0-9.]+`.
         .filter(|d| {
@@ -471,57 +472,12 @@ pub(crate) fn parse_meta(bytes: &[u8]) -> Option<serde_json::Value> {
         .next()?
         .ok()
 }
-/// A pack's Polytone config entries (`assets/<namespace>/polytone/config_entries/<name>.json`,
-/// in the pack's base, not its overlays) at their default values.
-pub fn polytone_configs(source: &Source) -> horizon_polytone::pack::Configs {
-    let mut configs = horizon_polytone::pack::Configs::default();
-    let id_of = |name: &str| -> Option<String> {
-        let rest = name.strip_prefix("assets/")?;
-        let (namespace, rest) = rest.split_once('/')?;
-        let entry = rest
-            .strip_prefix("polytone/config_entries/")?
-            .strip_suffix(".json")?;
-        Some(format!("{namespace}:{entry}"))
-    };
-    match source {
-        Source::Dir(d) => {
-            let Ok(namespaces) = fs::read_dir(d.join("assets")) else {
-                return configs;
-            };
-            for namespace in namespaces.flatten() {
-                let folder = namespace.path().join("polytone/config_entries");
-                for file in fs::read_dir(&folder).into_iter().flatten().flatten() {
-                    let name = format!(
-                        "assets/{}/polytone/config_entries/{}",
-                        namespace.file_name().to_string_lossy(),
-                        file.file_name().to_string_lossy()
-                    );
-                    if let (Some(id), Ok(bytes)) = (id_of(&name), fs::read(file.path()))
-                        && let Ok(json) = serde_json::from_slice(&bytes)
-                    {
-                        configs.add_entry(id, &json);
-                    }
-                }
-            }
-        }
-        Source::Zip(z) => {
-            let Ok(zip) = Zip::open(z) else {
-                return configs;
-            };
-            let names: Vec<String> = zip
-                .names()
-                .filter(|n| id_of(n).is_some())
-                .map(str::to_owned)
-                .collect();
-            for name in names {
-                if let (Some(id), Ok(bytes)) = (id_of(&name), zip.read(&name))
-                    && let Ok(json) = serde_json::from_slice(&bytes)
-                {
-                    configs.add_entry(id, &json);
-                }
-            }
-        }
-    }
+/// A pack's own options (Polytone's config entries, in the pack's base, not its overlays) at
+/// the values the player chose, else their defaults.
+pub fn polytone_configs(source: &Source) -> Configs {
+    let mut configs = crate::pack_hooks::formats()
+        .pack_options(source)
+        .unwrap_or_default();
     for (id, value) in polytone_choices() {
         if configs.entries().contains_key(&id) {
             configs.set(&id, value);
@@ -530,15 +486,15 @@ pub fn polytone_configs(source: &Source) -> horizon_polytone::pack::Configs {
     configs
 }
 
-/// A pack's Polytone config entries and one's value, for the game's Pack Options.
-pub use horizon_polytone::pack::{ConfigValue, Configs};
+/// A pack's options and one's value, for the game's Pack Options.
+pub use horizon_pack_options::{ConfigValue, Configs};
 
 /// The player's Polytone config choices (#11486): what they changed from the packs' defaults,
 /// by entry id, for every pack. `polytone_configs` lays them over each pack's defaults.
-static POLYTONE_CHOICES: std::sync::RwLock<BTreeMap<String, horizon_polytone::pack::ConfigValue>> =
+static POLYTONE_CHOICES: std::sync::RwLock<BTreeMap<String, ConfigValue>> =
     std::sync::RwLock::new(BTreeMap::new());
 
-pub fn polytone_choices() -> BTreeMap<String, horizon_polytone::pack::ConfigValue> {
+pub fn polytone_choices() -> BTreeMap<String, ConfigValue> {
     POLYTONE_CHOICES
         .read()
         .map(|c| c.clone())
@@ -546,7 +502,7 @@ pub fn polytone_choices() -> BTreeMap<String, horizon_polytone::pack::ConfigValu
 }
 
 /// Replaces the player's Polytone config choices (packs read them when they load again).
-pub fn set_polytone_choices(choices: BTreeMap<String, horizon_polytone::pack::ConfigValue>) {
+pub fn set_polytone_choices(choices: BTreeMap<String, ConfigValue>) {
     if let Ok(mut c) = POLYTONE_CHOICES.write() {
         *c = choices;
     }
@@ -558,8 +514,7 @@ pub fn polytone_choices_file() -> std::path::PathBuf {
 }
 
 /// Reads the choices from `path` (none when it is missing or broken).
-pub fn load_polytone_choices(path: &Path) -> BTreeMap<String, horizon_polytone::pack::ConfigValue> {
-    use horizon_polytone::pack::ConfigValue;
+pub fn load_polytone_choices(path: &Path) -> BTreeMap<String, ConfigValue> {
     let Ok(bytes) = fs::read(path) else {
         return BTreeMap::new();
     };
@@ -583,9 +538,8 @@ pub fn load_polytone_choices(path: &Path) -> BTreeMap<String, horizon_polytone::
 /// Writes the choices to `path`.
 pub fn save_polytone_choices(
     path: &Path,
-    choices: &BTreeMap<String, horizon_polytone::pack::ConfigValue>,
+    choices: &BTreeMap<String, ConfigValue>,
 ) -> std::io::Result<()> {
-    use horizon_polytone::pack::ConfigValue;
     let map: serde_json::Map<String, serde_json::Value> = choices
         .iter()
         .map(|(id, v)| {
@@ -856,7 +810,8 @@ fn build_overlay_uncached(
                     packs
                         .get(*owner)
                         .and_then(|p| {
-                            horizon_polytone::pack::sounds_without_unmet(&b, &p.polytone_configs)
+                            crate::pack_hooks::formats()
+                                .sounds_without_unmet(&b, &p.polytone_configs)
                         })
                         .unwrap_or(b),
                 ),
@@ -1606,6 +1561,7 @@ mod tests {
     }
     #[test]
     fn a_sound_entry_whose_polytone_condition_fails_is_left_out() {
+        crate::pack_formats::install();
         let base =
             std::env::temp_dir().join(format!("horizon-packs-sound-cond-{}", std::process::id()));
         let _ = fs::remove_dir_all(&base);
@@ -2121,6 +2077,7 @@ mod tests {
     }
     #[test]
     fn polytone_conditions_turn_overlays_on_from_the_packs_configs() {
+        crate::pack_formats::install();
         let dir =
             std::env::temp_dir().join(format!("horizon-packs-polytone-{}", std::process::id()));
         let _ = fs::remove_dir_all(&dir);

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

@@ -796,11 +796,31 @@ impl Host for Ctx<'_, '_> {
                 .registry
                 .configs
                 .get(id)
-                .map(horizon_polytone::pack::ConfigValue::to_value)
+                .map(horizon_polytone::pack::config_value)
                 .ok_or_else(|| format!("no config {id}")),
             _ => Err(format!("{name} is not available here")),
         }
     }
+
+    /// A particle's own fields, as `particle_method` answers them.
+    fn field(&mut self, root: Root, field: horizon_polytone::expr::Field) -> Option<V> {
+        use horizon_polytone::expr::Field as F;
+        let Subject::Particle(p) = &self.subject else {
+            return None;
+        };
+        if root != Root::Object {
+            return None;
+        }
+        Some(V::Num(match field {
+            F::Age => f64::from(p.age),
+            F::Life => f64::from(p.lifetime),
+            F::Custom => *self.custom,
+            F::X => p.position[0],
+            F::Y => p.position[1],
+            F::Z => p.position[2],
+            F::Temperature | F::Downfall => return None,
+        }))
+    }
 }
 
 fn eval(program: &Program, ctx: &mut Ctx) -> Option<f64> {

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

@@ -7,7 +7,10 @@
 //! sections are immutable behind `Arc` and edited through `Arc::make_mut`, so
 //! a weak reference tells an edited or replaced section from the one the list
 //! was built from (see `random_tick_sections`), without keeping its blocks.
-use crate::{chunk::Section, fast_hash::FxHashMap};
+use crate::{
+    chunk::{Chunk, Section},
+    fast_hash::FxHashMap,
+};
 use std::sync::{Arc, Mutex, Weak};
 
 /// A section's POIs: the block index in the section (`y << 8 | z << 4 | x`)
@@ -18,13 +21,16 @@ struct Cached<T> {
     section: Weak<Section>,
     pois: SectionPois<T>,
 }
-/// Cached POI lists by section, `(chunk x, section index, chunk z)`.
+/// Cached POI lists by chunk column `(chunk x, chunk z)`, each by section
+/// index: a search through a column looks it up once.
 pub struct PoiSections<T> {
     sections: Mutex<Lists<T>>,
 }
 struct Lists<T> {
-    by_section: FxHashMap<(i32, i32, i32), Cached<T>>,
-    /// Size above which lists of sections no longer resident are dropped.
+    by_column: FxHashMap<(i32, i32), Vec<Option<Cached<T>>>>,
+    /// How many section lists are kept, and the count above which the lists
+    /// of sections no longer resident are dropped.
+    len: usize,
     prune_at: usize,
 }
 const MIN_PRUNE: usize = 4096;
@@ -32,27 +38,61 @@ impl<T> Default for PoiSections<T> {
     fn default() -> Self {
         Self {
             sections: Mutex::new(Lists {
-                by_section: FxHashMap::default(),
+                by_column: FxHashMap::default(),
+                len: 0,
                 prune_at: MIN_PRUNE,
             }),
         }
     }
 }
-impl<T: Copy> PoiSections<T> {
-    /// The POIs of `section`, whose block states `kind` classifies. `kind`
-    /// must give the same answer for a state on every call.
-    pub fn get(
-        &self,
-        key: (i32, i32, i32),
-        section: &Arc<Section>,
-        mut kind: impl FnMut(u32) -> Option<T>,
-    ) -> SectionPois<T> {
-        let mut lists = self.sections.lock().unwrap_or_else(|e| e.into_inner());
-        if let Some(cached) = lists.by_section.get(&key)
-            && cached.section.as_ptr() == Arc::as_ptr(section)
-        {
-            return cached.pois.clone();
+impl<T: Copy> Lists<T> {
+    /// The column's lists, for sections up to `last`, after dropping the
+    /// lists of sections no longer resident if there are too many.
+    fn column(
+        &mut self,
+        column: (i32, i32),
+        last: usize,
+    ) -> (&mut [Option<Cached<T>>], &mut usize) {
+        if self.len >= self.prune_at {
+            self.prune();
         }
+        let lists = self.by_column.entry(column).or_default();
+        if lists.len() <= last {
+            lists.resize_with(last + 1, || None);
+        }
+        (lists, &mut self.len)
+    }
+
+    /// Drops the lists of sections no longer resident.
+    fn prune(&mut self) {
+        let mut len = 0;
+        self.by_column.retain(|_, lists| {
+            for c in lists.iter_mut() {
+                if c.as_ref().is_some_and(|c| c.section.strong_count() == 0) {
+                    *c = None;
+                }
+            }
+            let kept = lists.iter().filter(|c| c.is_some()).count();
+            len += kept;
+            kept > 0
+        });
+        self.len = len;
+        self.prune_at = (len * 2).max(MIN_PRUNE);
+    }
+}
+
+/// The POIs of `section` from `slot`, listed again (and kept there) unless
+/// `slot` was listed from this very section; `len` counts the slots filled.
+fn list<'a, T: Copy>(
+    slot: &'a mut Option<Cached<T>>,
+    len: &mut usize,
+    section: &Arc<Section>,
+    kind: &mut impl FnMut(u32) -> Option<T>,
+) -> &'a SectionPois<T> {
+    let fresh = slot
+        .as_ref()
+        .is_some_and(|c| c.section.as_ptr() == Arc::as_ptr(section));
+    if !fresh {
         let pois: SectionPois<T> = if section.blocks.maybe_has(|v| kind(v).is_some()) {
             let mut states = [0u32; 4096];
             section.unpack(&mut states);
@@ -64,18 +104,56 @@ impl<T: Copy> PoiSections<T> {
         } else {
             Arc::from([])
         };
-        if lists.by_section.len() >= lists.prune_at {
-            lists.by_section.retain(|_, c| c.section.strong_count() > 0);
-            lists.prune_at = (lists.by_section.len() * 2).max(MIN_PRUNE);
+        *len += usize::from(slot.is_none());
+        *slot = Some(Cached {
+            section: Arc::downgrade(section),
+            pois,
+        });
+    }
+    &slot.as_ref().expect("just listed").pois
+}
+
+impl<T: Copy> PoiSections<T> {
+    /// The POIs of `section`, the `key.1`-th section of the column
+    /// `(key.0, key.2)`, whose block states `kind` classifies. `kind` must give
+    /// the same answer for a state on every call.
+    pub fn get(
+        &self,
+        key: (i32, i32, i32),
+        section: &Arc<Section>,
+        mut kind: impl FnMut(u32) -> Option<T>,
+    ) -> SectionPois<T> {
+        let mut lists = self.sections.lock().unwrap_or_else(|e| e.into_inner());
+        let s = usize::try_from(key.1).expect("a section index");
+        let (column, len) = lists.column((key.0, key.2), s);
+        list(&mut column[s], len, section, &mut kind).clone()
+    }
+
+    /// The POIs of `chunk` from block Y `y0` to `y1`, its first section at
+    /// `min_y`, as [`Self::get`] gives them: each section that has any, with
+    /// the Y of its lowest blocks, in order, put in `out`. One lookup of the
+    /// column.
+    pub fn column(
+        &self,
+        chunk: &Chunk,
+        min_y: i32,
+        (y0, y1): (i32, i32),
+        mut kind: impl FnMut(u32) -> Option<T>,
+        out: &mut Vec<(i32, SectionPois<T>)>,
+    ) {
+        out.clear();
+        let (first, last) = ((y0 - min_y) >> 4, (y1 - min_y) >> 4);
+        if first > last {
+            return;
+        }
+        let mut lists = self.sections.lock().unwrap_or_else(|e| e.into_inner());
+        let (slots, len) = lists.column((chunk.x, chunk.z), last as usize);
+        for s in first as usize..=last as usize {
+            let pois = list(&mut slots[s], len, &chunk.sections[s], &mut kind);
+            if !pois.is_empty() {
+                out.push((min_y + s as i32 * 16, pois.clone()));
+            }
         }
-        lists.by_section.insert(
-            key,
-            Cached {
-                section: Arc::downgrade(section),
-                pois: pois.clone(),
-            },
-        );
-        pois
     }
 }
 
@@ -143,6 +221,48 @@ mod tests {
         assert!(index.get((0, 0, 0), &chunk.sections[0], kind).is_empty());
     }
 
+    /// A column gives each section's list as `get` does, the sections
+    /// without any left out, and keeps them until a section changes.
+    #[test]
+    fn a_column_gives_what_each_section_gives() {
+        let index = PoiSections::<u8>::default();
+        let kind = |v: u32| (v == 5).then_some(5);
+        let mut chunk = Arc::new(Chunk::empty(2, -3));
+        for (x, y, z) in [(1, MIN_Y + 2, 3), (4, MIN_Y + 40, 0), (0, MIN_Y + 41, 15)] {
+            Arc::make_mut(&mut chunk).set(x, y, z, 5);
+        }
+        let mut out = Vec::new();
+        index.column(&chunk, MIN_Y, (MIN_Y, MIN_Y + 63), kind, &mut out);
+        let bases: Vec<i32> = out.iter().map(|(base, _)| *base).collect();
+        assert_eq!(bases, [MIN_Y, MIN_Y + 32]);
+        for (base, pois) in &out {
+            let s = (base - MIN_Y) / 16;
+            let one = index.get((2, s, -3), &chunk.sections[s as usize], kind);
+            assert!(Arc::ptr_eq(pois, &one));
+        }
+        // Kept: no rescan.
+        index.column(
+            &chunk,
+            MIN_Y,
+            (MIN_Y, MIN_Y + 63),
+            |_| panic!("rescanned"),
+            &mut out,
+        );
+        assert_eq!(out.len(), 2);
+        // An edit lists that section again.
+        Arc::make_mut(&mut chunk).set(4, MIN_Y + 40, 0, 1);
+        let mut rescans = 0;
+        let counted = |v: u32| {
+            rescans += 1;
+            kind(v)
+        };
+        index.column(&chunk, MIN_Y, (MIN_Y + 20, MIN_Y + 63), counted, &mut out);
+        assert!(rescans > 0);
+        assert_eq!(out.len(), 1);
+        assert_eq!(out[0].0, MIN_Y + 32);
+        assert_eq!(&*out[0].1, &[(9 << 8 | 15 << 4, 5)]);
+    }
+
     #[test]
     fn unloaded_sections_are_dropped() {
         let index = PoiSections::<u8>::default();
@@ -153,7 +273,7 @@ mod tests {
             index.get((1, i, 0), &Arc::new(Section::default()), kind);
         }
         let lists = index.sections.lock().unwrap();
-        assert!(lists.by_section.len() <= 2);
-        assert!(lists.by_section.contains_key(&(0, 0, 0)));
+        assert!(lists.len <= 2);
+        assert!(lists.by_column[&(0, 0)][0].is_some());
     }
 }

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

@@ -337,6 +337,13 @@ impl Settings {
             .and_then(|mode| self.video_modes.iter().position(|m| *m == mode))
             .map_or(-1, |i| i as i32)
     }
+    /// Loads only the crates' settings stores (`horizon_hooks::settings`) from the files next to
+    /// `path`, into the seat whose turn it is (`horizon_hooks::seat`): a splitscreen player whose
+    /// settings were made from P1's rather than loaded.
+    pub fn load_stores(path: &Path) {
+        let dir = path.parent();
+        horizon_hooks::settings::engine::load(&mut |file| fs::read_to_string(dir?.join(file)).ok());
+    }
     pub fn load(path: &Path) -> Self {
         let mut horizon = path
             .parent()

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

@@ -237,17 +237,17 @@ impl<P: Copy, S: Copy> Lines<P, S> {
 pub(crate) fn backdrop(batch: &mut HudBatch, atlas: &HudAtlas, in_world: bool) {
     let (w, h) = (batch.width, batch.height);
     ui::menu_background(batch, atlas, 0.0, 0.0, w, h, in_world);
-    style::fill(batch, atlas, [0.0, 0.0, w, h], style::VEIL);
+    style::fill(batch, atlas, [0.0, 0.0, w, h], style::veil());
 }
 
 /// The mark and the screen's name over the search field.
 pub(crate) fn mark(batch: &mut HudBatch, atlas: &HudAtlas, cols: &Columns, title: &str) {
     let (x, y) = (cols.side_x, cols.side_y);
-    style::fill(batch, atlas, [x, y + 2.0, 6.0, 6.0], style::ACCENT);
+    style::fill(batch, atlas, [x, y + 2.0, 6.0, 6.0], style::accent());
     let horizon = Text::literal("Horizon");
     batch.text_styled(atlas, &horizon, x + 10.0, y, style::WHITE, true);
     let title = Text::literal(title);
-    batch.text_styled(atlas, &title, x, y + 10.0, style::MUTED, true);
+    batch.text_styled(atlas, &title, x, y + 10.0, style::muted(), true);
 }
 
 /// A page in the page list: the open page on a plate with the accent's bar beside it, the
@@ -273,13 +273,13 @@ pub(crate) fn page_tab(
         crate::widgets::target_as(rect, crate::widgets::Kind::Tab(open));
     }
     if open {
-        style::fill(batch, atlas, rect, style::OPEN);
-        style::fill(batch, atlas, [px, py, 2.0, ph], style::ACCENT);
+        style::fill(batch, atlas, rect, style::open());
+        style::fill(batch, atlas, [px, py, 2.0, ph], style::accent());
     }
     let color = match (open || hover, has) {
         (true, _) => style::WHITE,
-        (false, true) => style::SOFT,
-        (false, false) => style::MUTED,
+        (false, true) => style::soft(),
+        (false, false) => style::muted(),
     };
     let ty = py + ((ph - 8.0) / 2.0).floor();
     let name = Text::literal(style::fit(atlas, name, pw - 12.0));
@@ -312,12 +312,12 @@ pub(crate) fn search_field(
     search.draw(batch, atlas, None);
     if search.value.is_empty() && !focused {
         let hint = Text::literal(search.message.clone());
-        batch.text_styled(atlas, &hint, x + 5.0, search.y, style::MUTED, true);
+        batch.text_styled(atlas, &hint, x + 5.0, search.y, style::muted(), true);
     }
     if !search.value.is_empty() {
         let hover = ui::hovered(cursor, clear[0], clear[1], clear[2], clear[3]);
         crate::widgets::widget_cursor(hover, true);
-        let color = if hover { style::WHITE } else { style::MUTED };
+        let color = if hover { style::WHITE } else { style::muted() };
         let cy = y + ((h - 8.0) / 2.0).floor();
         ui::centered_text(
             batch,
@@ -344,7 +344,7 @@ pub(crate) fn plate(batch: &mut HudBatch, atlas: &HudAtlas, cols: &Columns, head
         batch,
         atlas,
         [px + 8.0, py + 24.0, pw - 16.0, 1.0],
-        style::HEAD_RULE,
+        style::head_rule(),
     );
 }
 
@@ -383,9 +383,9 @@ pub(crate) fn list<P: Copy, S: Copy>(
         }
         let Some(setting) = line.setting else {
             let (name, color, dy) = match line.group {
-                Some(("", _)) => (page_name(line.page), style::MUTED, 3.0),
-                Some((name, _)) => (lang::get(name), style::MUTED, 3.0),
-                None => (page_name(line.page), style::ACCENT, 4.0),
+                Some(("", _)) => (page_name(line.page), style::muted(), 3.0),
+                Some((name, _)) => (lang::get(name), style::muted(), 3.0),
+                None => (page_name(line.page), style::accent(), 4.0),
             };
             let name = Text::literal(name);
             batch.text_styled(atlas, &name, cols.list_x + 2.0, y + dy, color, true);
@@ -393,7 +393,7 @@ pub(crate) fn list<P: Copy, S: Copy>(
         };
         if !after_name {
             let rule = [cols.list_x + 8.0, y, cols.list_w - 16.0, 1.0];
-            style::fill(batch, atlas, rule, style::ROW_RULE);
+            style::fill(batch, atlas, rule, style::row_rule());
         }
         row(batch, setting, y);
     }
@@ -404,7 +404,7 @@ pub(crate) fn list<P: Copy, S: Copy>(
             &none,
             cols.list_x + 2.0,
             cols.top + 4.0,
-            style::MUTED,
+            style::muted(),
             true,
         );
     }
@@ -499,7 +499,7 @@ pub(crate) fn row(batch: &mut HudBatch, atlas: &HudAtlas, cols: &Columns, y: f32
     let active = live && (hover || focused || held);
     if active {
         let lit = [rect[0] + 2.0, y + 1.0, rect[2] - 4.0, style::ROW - 2.0];
-        style::fill(batch, atlas, lit, style::HOVER);
+        style::fill(batch, atlas, lit, style::hover());
     }
     crate::widgets::widget_cursor(hover, live);
     // The control socket's widget tree, the narrator and a controller's focus.
@@ -523,8 +523,8 @@ pub(crate) fn row(batch: &mut HudBatch, atlas: &HudAtlas, cols: &Columns, y: f32
     if live {
         crate::widgets::target_as(rect, kind);
     }
-    let color = if live { style::WHITE } else { style::MUTED };
-    let soft = if live { style::SOFT } else { style::MUTED };
+    let color = if live { style::WHITE } else { style::muted() };
+    let soft = if live { style::soft() } else { style::muted() };
     let ty = y + ((style::ROW - 8.0) / 2.0).floor();
     let lit = live && (hover || held);
     let left = rect[0] + style::INSET;
@@ -611,7 +611,7 @@ fn lit(batch: &mut HudBatch, atlas: &HudAtlas, [x, y, w, _]: [f32; 4]) {
         batch,
         atlas,
         [x + 2.0, y + 1.0, w - 4.0, style::ROW - 2.0],
-        style::HOVER,
+        style::hover(),
     );
 }
 
@@ -644,7 +644,7 @@ fn read_row(
     let room = rect[2] - 2.0 * style::INSET - name_w - 8.0;
     let value = style::fit(atlas, value, room);
     let vx = rect[0] + rect[2] - style::INSET - atlas.font.width(&value);
-    batch.text_styled(atlas, &Text::literal(value), vx, ty, style::SOFT, true);
+    batch.text_styled(atlas, &Text::literal(value), vx, ty, style::soft(), true);
     if focused {
         style::ring(
             batch,
@@ -749,7 +749,7 @@ fn pad_row(batch: &mut HudBatch, atlas: &HudAtlas, cols: &Columns, y: f32, view:
         batch.text_styled(atlas, &yellow(close), right.ceil(), ty, style::WHITE, true);
     }
     let left = rect[0] + style::INSET;
-    let color = if live { style::WHITE } else { style::MUTED };
+    let color = if live { style::WHITE } else { style::muted() };
     let shown = Text::literal(style::fit(atlas, name, chip[0] - 6.0 - left));
     batch.text_styled(atlas, &shown, left, ty, color, true);
     if focused {
@@ -799,7 +799,7 @@ fn side_lines(
         ];
         crate::widgets::record(line, rect, false);
         let shown = Text::literal(style::fit(atlas, line, rect[2]));
-        batch.text_styled(atlas, &shown, rect[0], rect[1], style::MUTED, true);
+        batch.text_styled(atlas, &shown, rect[0], rect[1], style::muted(), true);
     }
 }
 /// A line under the page list: its inset, and its height.
@@ -881,7 +881,7 @@ fn heading(batch: &mut HudBatch, atlas: &HudAtlas, text: &str, [x, y, w, _]: [f3
     let rect = [x + SIDE_INSET, y + HEADING_Y, w - 2.0 * SIDE_INSET, 8.0];
     crate::widgets::record(text, rect, false);
     let shown = Text::literal(style::fit(atlas, text, rect[2]));
-    batch.text_styled(atlas, &shown, rect[0], rect[1], style::MUTED, true);
+    batch.text_styled(atlas, &shown, rect[0], rect[1], style::muted(), true);
 }
 
 /// Vanilla's scroller, inside the panel's right edge, sized as `ui::Scroll` drags it.
@@ -1896,8 +1896,8 @@ impl<S: Screen> Shell<S> {
             // The row's page is open: lit as the list's open page is.
             if list.lit == Some(*shown) {
                 let row @ [x, y, _, h] = strip.area;
-                style::fill(batch, atlas, row, style::OPEN);
-                style::fill(batch, atlas, [x, y, 2.0, h], style::ACCENT);
+                style::fill(batch, atlas, row, style::open());
+                style::fill(batch, atlas, [x, y, 2.0, h], style::accent());
             }
             tabs::draw(batch, atlas, strip);
         }
@@ -2134,7 +2134,14 @@ impl<S: Screen> Shell<S> {
             crate::widgets::narratable(|| crate::widgets::Narratable::text(row.name.clone(), rect));
             let ty = y + ((style::ROW - 8.0) / 2.0).floor();
             let name = Text::literal(style::fit(atlas, &row.name, rect[2] - 2.0 * style::INSET));
-            batch.text_styled(atlas, &name, rect[0] + style::INSET, ty, style::MUTED, true);
+            batch.text_styled(
+                atlas,
+                &name,
+                rect[0] + style::INSET,
+                ty,
+                style::muted(),
+                true,
+            );
             return;
         }
         let over = |[x, y, w, h]: [f32; 4]| pointer.is_some_and(|at| ui::hovered(at, x, y, w, h));
@@ -2240,7 +2247,7 @@ impl<S: Screen> Shell<S> {
         // Labelled for the widget tree: what the strip says is what a test or an agent reads.
         crate::widgets::record(about, cols.dock, false);
         let color = if why.is_some() {
-            style::MUTED
+            style::muted()
         } else {
             style::GREY
         };

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

@@ -913,6 +913,20 @@ pub trait Backend {
     fn unpause(&mut self, channel: ChannelId);
     /// `Channel.stopped`.
     fn stopped(&mut self, channel: ChannelId) -> bool;
+    /// Update volume, pitch, and position in a single backend call.
+    fn update_channel(&mut self, channel: ChannelId, volume: f32, pitch: f32, position: [f64; 3]) {
+        self.set_volume(channel, volume);
+        self.set_pitch(channel, pitch);
+        self.set_position(channel, position);
+    }
+    /// Filter which handles have stopped playing in a single pass.
+    fn filter_stopped(&mut self, live: &[(u64, ChannelId)], stopped: &mut Vec<u64>) {
+        for &(h, c) in live {
+            if self.stopped(c) {
+                stopped.push(h);
+            }
+        }
+    }
     /// Whether the channel plays clearly through a mod's muffle (`Audio::muffle`): its sound
     /// event is one the mod exempted. A backend without a muffle ignores it.
     fn set_unmuffled(&mut self, _channel: ChannelId, _unmuffled: bool) {}
@@ -1494,13 +1508,14 @@ impl SoundEngine {
                 .iter()
                 .filter_map(|(h, handle)| handle.channel.map(|c| (*h, c))),
         );
-        for (h, c) in live.drain(..) {
-            if backend.stopped(c) {
-                self.release_handle(h, backend);
-            }
+        let mut stopped = std::mem::take(&mut self.mapped_scratch);
+        stopped.clear();
+        backend.filter_stopped(&live, &mut stopped);
+        for h in stopped.drain(..) {
+            self.release_handle(h, backend);
         }
         // Released handles nobody maps any more.
-        let mut mapped = std::mem::take(&mut self.mapped_scratch);
+        let mut mapped = stopped;
         mapped.clear();
         mapped.extend(self.instance_to_channel.iter().map(|(_, h)| *h));
         self.handles
@@ -1550,9 +1565,7 @@ impl SoundEngine {
                 h.pitch_edited = pitch_edited;
             }
             if let Some(c) = self.handles.get(&handle).and_then(handle_channel) {
-                backend.set_volume(c, volume);
-                backend.set_pitch(c, pitch);
-                backend.set_position(c, position);
+                backend.update_channel(c, volume, pitch, position);
             }
             let instance = self.instances.get_mut(&id).expect("present");
             if instance.looping

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

@@ -304,19 +304,19 @@ impl StudioUi {
 
                 // Card background & highlight
                 if is_selected {
-                    style::fill(batch, atlas, rect, style::OPEN);
+                    style::fill(batch, atlas, rect, style::open());
                 } else if is_hovered {
-                    style::fill(batch, atlas, rect, style::HOVER);
+                    style::fill(batch, atlas, rect, style::hover());
                 } else {
                     style::well(batch, atlas, rect);
                 }
 
                 let border_color = if is_selected {
-                    style::ACCENT
+                    style::accent()
                 } else if is_hovered {
                     style::WHITE
                 } else {
-                    style::ROW_RULE
+                    style::row_rule()
                 };
                 style::ring(batch, atlas, rect, border_color);
 

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

@@ -1251,6 +1251,9 @@ pub struct EditBox {
     /// `getMessage`: what the narrator calls the box ("<message> edit box:
     /// <value>").
     pub message: String,
+    /// `EditBox.setInvertHighlightedTextColor`: a selection draws its text
+    /// inverted (the default) or in the box's own colour (`AnvilScreen`).
+    pub invert_highlighted_text_color: bool,
     /// Where a borderless box drawn in a frame of its own focuses: a controller's outline goes
     /// round the frame, not over the text.
     pub frame: Option<[f32; 4]>,
@@ -1543,6 +1546,7 @@ impl EditBox {
             text_color_uneditable: rgba(112, 112, 112, 255),
             editable: true,
             message: String::new(),
+            invert_highlighted_text_color: true,
             frame: None,
         }
     }
@@ -1918,7 +1922,11 @@ impl EditBox {
             let right = self.x + self.width;
             let (x0, x1) = (cursor_x.min(right), (hx - 1.0).min(right));
             let (a, b) = (x0.min(x1), x0.max(x1));
-            batch.text_highlight(atlas, (a, ty - 1.0, b - a, 11.0), true);
+            batch.text_highlight(
+                atlas,
+                (a, ty - 1.0, b - a, 11.0),
+                self.invert_highlighted_text_color,
+            );
         }
         if show_cursor {
             if insert {
@@ -2628,6 +2636,20 @@ mod tests {
         );
     }
 
+    /// `EditBox.setInvertHighlightedTextColor`: a selection inverts its text
+    /// unless the box asks it not to (the anvil's rename box).
+    #[test]
+    fn a_selection_inverts_its_text_unless_the_box_says_not_to() {
+        let mut edit = EditBox::new(0.0, 0.0, 100.0, 20.0);
+        assert!(edit.invert_highlighted_text_color);
+        edit.invert_highlighted_text_color = false;
+        edit.set_value("name");
+        edit.set_cursor(0, false);
+        edit.set_cursor(4, true);
+        assert_eq!(edit.selected_text(), "name");
+        assert!(!edit.invert_highlighted_text_color);
+    }
+
     /// `EditBox.setEditable(false)`: the box keeps the focus, the caret keys
     /// and copy, but `charTyped`/paste/Backspace/Delete do nothing, and Cut
     /// copies without taking the text out. A value and the caret still show,

crates/horizon-client/Cargo.toml

@@ -119,13 +119,11 @@ audio = ["horizon-client-render/audio", "horizon-client-lib/audio"]
 controllers = ["horizon-client-lib/controllers", "dep:gilrs", "dep:horizon-dualsense", "horizon-client-input/controllers"]
 # Horizon's own extras over the vanilla game, for a fork that wants them out (docs/forking.md):
 # cosmetics and emotes, the "Horizon player" presence, the official server added to
-# the server list, the Horizon Settings and Mods pages, Discord and Play with Friends. Players always get them; there is no switch. `grep -rn horizon-extras crates/` lists
+# the server list, the Horizon Settings and Mods pages and Play with Friends, and ray tracing on
+# request (`HORIZON_RAY_TRACING=1`). Players always get them; there is no switch. `grep -rn horizon-extras crates/` lists
 # every place it gates. Without it (`--no-default-features --features audio,controllers`) the
 # client is best effort: CI builds only the default.
-horizon-extras = ["horizon-client-lib/horizon-extras", "discord", "friends"]
-# Online extras a server or a port can leave out; the server build has none of them. "Playing Horizon"
-# on Discord (game/discord.rs).
-discord = ["horizon-client-lib/discord"]
+horizon-extras = ["horizon-client-render/horizon-extras", "friends"]
 # Play with Friends: sharing a world behind an invite code (game/friends.rs). Joining one is
 # horizon-friends' `game` side, which horizon-official registers (`horizon_hooks::tunnel`).
 friends = ["dep:horizon-friends"]

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

@@ -287,6 +287,7 @@
   "This feature is not yet available in Horizon.": "This feature is not yet available in Horizon.",
   "Your display or system doesn't offer HDR output.": "Your display or system doesn't offer HDR output.",
   "Turn HDR on to use it.": "Turn HDR on to use it.",
+  "The shader pack lights the world itself.": "The shader pack lights the world itself.",
   "Your GPU or graphics API doesn't support it.": "Your GPU or graphics API doesn't support it.",
   "Not with software rendering, which runs it on the CPU.": "Not with software rendering, which runs it on the CPU.",
   "Out of video memory: off until the next start.": "Out of video memory: off until the next start.",

crates/horizon-client/examples/model_library_bench.rs

@@ -50,6 +50,8 @@ unsafe impl GlobalAlloc for CountingAllocator {
 static ALLOCATOR: CountingAllocator = CountingAllocator;
 
 fn main() -> horizon_client::Result<()> {
+    // The pack formats the game installs at startup, so their loading is measured too.
+    horizon_client::pack_formats::install();
     let root = std::env::args()
         .nth(1)
         .ok_or("usage: model_library_bench ROOT [--parity]")?;

crates/horizon-client/src/client_lib.rs

@@ -14,19 +14,20 @@ pub use horizon_client_render::{
     block_entities, block_entity_anim, block_entity_render, block_sprites, block_states, bluemap,
     bluemap_detect, border_render, breaking, brewing, camera, chat, chunk, chunk_map, cit,
     cit_armor, cit_assets, cit_glint, client_resources, clouds, collisions, command_block,
-    containers, controller_ui, crash, custom_sky, datapack, dynamic_light, effects, environment,
-    extras, fast_hash, fluid_render, fog, font, gfx, graphics, graphics_style, graphics_ui,
-    hdr_calibration, hud, hud_kit, hud_layout, hud_overlays, inventory_effects, java_text,
-    jigsaw_block, json_folder, level_loading, light, lod, logging, menu_blur, mesher, minimap,
-    mipmap, mod_browser, mod_list, model_library, models, multiline_edit, native_emissive,
-    options_file, options_fixes, options_ui, overlay, pack_browser, pack_formats, pack_hooks,
-    pack_palette, pack_screen, packs, pad_cursor, pad_glyph, par, particles, poi_sections,
-    polytone_creative_tabs, polytone_post, post_chain, potent_sulfur, preedit, providers, pvp,
-    pvp_hud, random_source, screen_draw, screen_effects, sculk, section_mask, server_terrain,
-    settings, shader_options, shader_pack_list, signs, skins, social, sound_engine, sound_events,
-    sound_preview, spans, split_layout, split_map, split_profiles, sprites, streaming,
-    structure_block, tab_list, terrain_model, test_block, test_instance_block, testgen,
-    title_edition, trims, ui, vault, weather, widgets, world, worldborder, zip,
+    containers, controller_ui, crash, custom_sky, datapack, dynamic_light, effects,
+    entity_textures, environment, extras, fast_hash, fluid_render, fog, font, gfx, graphics,
+    graphics_style, graphics_ui, hdr_calibration, hud, hud_kit, hud_layout, hud_overlays,
+    inventory_effects, java_text, jigsaw_block, json_folder, level_loading, light, lod, logging,
+    menu_blur, menu_style, mesher, minimap, mipmap, mod_browser, mod_list, model_library, models,
+    multiline_edit, native_emissive, options_file, options_fixes, options_ui, overlay,
+    pack_browser, pack_formats, pack_hooks, pack_palette, pack_screen, packs, pad_cursor,
+    pad_glyph, par, particles, poi_sections, polytone_creative_tabs, polytone_post, post_chain,
+    potent_sulfur, preedit, providers, pvp, pvp_hud, random_source, screen_draw, screen_effects,
+    sculk, section_mask, server_terrain, settings, shader_options, shader_pack_list, signs, skins,
+    social, sound_engine, sound_events, sound_preview, spans, split_layout, split_map,
+    split_profiles, sprites, streaming, structure_block, tab_list, terrain_model, test_block,
+    test_instance_block, testgen, title_edition, trims, ui, vault, weather, widgets, world,
+    worldborder, zip,
 };
 pub mod attack_strength;
 pub mod attribute_updates;
@@ -58,8 +59,6 @@ pub mod debug_overlay;
 pub mod debugworld;
 pub mod dialog;
 pub mod dialog_screen;
-#[cfg(feature = "discord")]
-pub mod discord_presence;
 pub mod end_crystal;
 pub mod end_gateway;
 pub mod entities;
@@ -91,6 +90,7 @@ pub mod locator_bar;
 pub mod lod_net;
 pub mod menu;
 pub mod merchant;
+pub mod mob_formats;
 pub mod mobs;
 pub mod mod_content;
 pub mod mod_registry;
@@ -102,8 +102,6 @@ pub mod native_data;
 pub mod net;
 pub mod nether_portal;
 pub mod no_resources;
-#[cfg(feature = "horizon-extras")]
-pub mod official_servers;
 pub mod offline_name;
 pub mod old_world;
 pub mod osk;
@@ -171,6 +169,7 @@ pub use horizon_client_input::gamepad;
 pub use horizon_client_input::gameplay_guide;
 pub use horizon_client_input::held;
 pub use horizon_client_input::input;
+pub use horizon_client_input::input_source;
 pub use horizon_client_input::interaction_input;
 pub use horizon_client_input::key_names;
 pub use horizon_client_input::keybinds;

crates/horizon-client/src/entry.rs

@@ -13,8 +13,10 @@ pub fn main_with(mods: crate::mod_api::Mods) {
         log::warn!("Trait mods already installed; ignoring the second list");
     }
     horizon_threads::configure_allocator();
+    crate::horizon_look::give();
     // OptiFine's and Polytone's pack formats (platform, docs/layers.md), before any pack loads.
     horizon_client::pack_formats::install();
+    horizon_client::mob_formats::install();
     // horizon-extras (docs/forking.md): without the feature, no Horizon Settings or Mods page.
     if !cfg!(feature = "horizon-extras") {
         horizon_client::options_ui::HORIZON_EXTRAS
@@ -23,8 +25,9 @@ pub fn main_with(mods: crate::mod_api::Mods) {
     horizon_client::telemetry::mark_start();
     // Opt-in telemetry keeps each crash report (docs/telemetry.md), whatever the mode.
     crash::on_report(horizon_client::telemetry::keep_crash);
-    // Crates above the engine registered their hooks before this (horizon-official's `main`);
-    // none registers after this point.
+    // Crates above the engine registered their hooks before this (horizon-official's `main`),
+    // then the Horizon parts still in this crate; none registers after this point.
+    game::player_hooks::register();
     horizon_hooks::engine::seal();
     horizon_client::spans::startup::init(std::time::Instant::now());
     horizon_client::spans::trace::start_from_env();

crates/horizon-client/src/game.rs

@@ -49,6 +49,7 @@ fn pack_files(world_tables: &Option<WorldTables>) -> horizon_world::loot::PackOv
     }
 }
 
+mod activity;
 mod advancements;
 mod advancements_screen;
 mod agent;
@@ -128,8 +129,6 @@ mod decorated_pot;
 mod dedicated;
 mod deflect;
 mod dialogs;
-#[cfg(feature = "discord")]
-mod discord;
 mod dispense_fixture;
 mod dispenser;
 mod dragon;
@@ -373,6 +372,7 @@ mod place_feature_tests;
 mod play_input;
 mod play_keys;
 mod player_equip;
+pub(crate) mod player_hooks;
 mod player_spawn;
 mod pointer_capture;
 #[cfg(test)]
@@ -402,6 +402,7 @@ mod remote_vehicles;
 mod render_control;
 mod render_settings;
 mod render_tick;
+mod replay;
 mod repro;
 mod resource_load;
 mod resource_loader;
@@ -1497,7 +1498,7 @@ impl LevelAccess for GameLevel<'_> {
             };
         }
         if let Some(signal) = books::lectern_signal(self.world, pos) {
-            return signal;
+            return signal * i32::from(books::has_book_state(self.registry, state));
         }
         if let Some(signal) =
             machines::shelf_signal(self.world, self.registry, state, pos, direction)
@@ -2882,19 +2883,9 @@ struct Game<'a> {
     /// The open connection joined from Realms: `ServerData.isRealm` for the friends
     /// service's presence status.
     realm_session: bool,
-    /// Active packet replay session (game/studio.rs).
-    pub(super) studio_replay: Option<horizon_client::studio::ReplayDriver>,
-    pub(super) studio_freecam: horizon_client::studio::StudioFreecam,
-    pub(super) studio_timeline: horizon_client::studio::TimelineUi,
-    pub(super) studio_topbar: horizon_client::studio::TopBarUi,
-    pub(super) studio_rmb_down: bool,
-    studio_camera_track_dirty: bool,
-    /// Camera perspective to restore after leaving replay playback.
-    studio_replay_previous_camera_type: Option<perspective::CameraType>,
-    /// Replay opened from the title screen owns the synthetic remote session.
-    studio_replay_standalone: bool,
-    last_replay_tick: Option<Instant>,
-    pub(super) studio_virtual_tick_ms: f32,
+    /// Replay playback (game/replay.rs), and Horizon Studio's editor on it (game/studio.rs).
+    pub(super) replay: replay::Replay,
+    pub(super) studio: studio::Studio,
     /// This world is open to the network (game/lan.rs).
     lan: Option<lan::LanHost>,
     /// Single player's server thread, which `remote` is connected to.
@@ -5026,7 +5017,7 @@ impl Game<'_> {
         if canceled {
             return Ok(false);
         }
-        self.pad_rumble(horizon_client::gamepad::Rumble::BlockBroken);
+        self.input_feedback(horizon_client::input_source::Feedback::BlockBroken);
         let broken = state;
         let facts = self.res.facts().get(state).clone();
         let state = self.crack_mined_pot(pos, state);
@@ -5845,7 +5836,7 @@ impl Game<'_> {
         batch
     }
     fn hud_layers(&mut self, size: [u32; 2]) -> HudBatch {
-        self.pad.guide_shown.clear();
+        self.input_hud_begin();
         let mut batch = HudBatch::new(size);
         batch.glint_colour = self.settings.extras.pvp.tweaks.glint_texel();
         // GlobalSettingsUniform's GameTime, for a resource pack's text shader.
@@ -5942,8 +5933,7 @@ impl Game<'_> {
         // the sleep overlay, debug screen and open screens still draw.
         let spectator = self.spectator();
         let (wi, hi) = (w as i32, h as i32);
-        let in_studio = self.studio_replay.is_some();
-        let show_hud = !self.ui.hide_gui && !in_studio;
+        let show_hud = !self.ui.hide_gui && !self.replay.playing();
         // Hud.extractRenderState asks `Screen.isInGameUi` twice: such a screen
         // defers the subtitles over itself, and keeps them while F1 hides the
         // rest of the HUD.
@@ -6282,23 +6272,7 @@ impl Game<'_> {
             self.draw_sign_editor(&mut batch);
             self.draw_book(&mut batch);
         }
-        if !self.ui.hide_gui
-            && self.screen == Screen::Playing
-            && (self.studio_replay.is_some() || self.studio_freecam.active)
-        {
-            self.studio_topbar.render(
-                &mut batch,
-                &self.gui.atlas,
-                self.cursor,
-                self.studio_freecam.locked_to_path,
-            );
-            self.studio_timeline.render(
-                &mut batch,
-                &self.gui.atlas,
-                self.cursor,
-                &self.studio_freecam,
-            );
-        }
+        self.draw_studio_bars(&mut batch);
         if show_hud {
             self.draw_pad_guide(&mut batch, guide_from);
         }
@@ -6521,12 +6495,12 @@ impl Game<'_> {
     /// `Camera.setRotation`: the camera's orientation, turned round in
     /// third-person front view.
     pub(super) fn camera_orientation(&self) -> glam::Quat {
-        if self.studio_freecam.active {
+        if self.studio.flying() {
             return camera_rotation(
                 perspective::CameraType::FirstPerson,
-                self.studio_freecam.yaw,
-                self.studio_freecam.pitch,
-            ) * glam::Quat::from_rotation_z(self.studio_freecam.roll.to_radians());
+                self.studio.freecam.yaw,
+                self.studio.freecam.pitch,
+            ) * glam::Quat::from_rotation_z(self.studio.freecam.roll.to_radians());
         }
         match self.posed_rotation {
             // The frame's camera, already turned round in front view.
@@ -6733,11 +6707,7 @@ impl Game<'_> {
         self.mark_player(out.len(), !self.own_body_in_view());
         let player_start = out.len();
         self.mark_motion(player_start, Self::MOTION_OWN_PLAYER);
-        let player_alpha = if self.studio_replay.is_some() {
-            (self.studio_virtual_tick_ms as f64 / 50.0).clamp(0.0, 1.0)
-        } else {
-            self.clock.camera_fraction()
-        };
+        let player_alpha = self.own_player_alpha();
         self.player_model_geometry(camera, player_alpha, &mut out);
         // A native pack's shadow pass alone gets the first-person model (no per-entity draws).
         if self.pack_ids.is_none() && !self.own_body_in_view() {
@@ -6746,8 +6716,8 @@ impl Game<'_> {
                 .extend(out.drain(player_start..));
         }
         self.mark_motion(out.len(), 0);
-        // Companions in first person, trails and auras (game/cosmetics/fx.rs).
-        self.cosmetics_fx_geometry(camera, alpha, &mut out);
+        // What crates draw around players: first person, see-through (game/player_hooks.rs).
+        self.players_after_geometry(camera, alpha, &mut out);
         self.mark_entity(out.len(), "minecraft:evoker_fangs");
         self.fangs_geometry(camera, alpha, &mut out);
         self.block_item_display_geometry(camera, alpha, &mut out);
@@ -7466,7 +7436,6 @@ impl Game<'_> {
         self.spawn_phantoms();
         self.tick_advancements();
         self.tick_player_model();
-        self.tick_emotes();
         Ok(())
     }
 
@@ -9236,7 +9205,7 @@ impl Game<'_> {
         let camera_alpha = self.clock.camera_fraction();
         let vanilla = self.camera_view(camera_alpha as f32);
         let view = vanilla.map(|view| {
-            if self.shows_panorama() || self.studio_freecam.active {
+            if self.shows_panorama() || self.studio.flying() {
                 view
             } else {
                 self.native_camera_pose_now(camera_alpha as f32, view)
@@ -9414,14 +9383,7 @@ impl Game<'_> {
         // hitboxes (F3+G, F3+B).
         let mut lines = self.fishing_line(alpha, size);
         let mut g = self.debug_gizmos(alpha as f32, camera.to_array());
-        if self.studio_freecam.active || self.studio_replay.is_some() {
-            horizon_client::studio::render_camera_path(
-                &self.studio_freecam.track,
-                &mut g,
-                None,
-                100,
-            );
-        }
+        self.studio_camera_path(&mut g);
         lines.extend(g.lines);
         let on_top = g.on_top;
         pr.lap("pr_debug");
@@ -9443,7 +9405,7 @@ impl Game<'_> {
             Vec::new()
         };
         pr.lap("pr_native_visuals");
-        let view = if self.studio_freecam.active {
+        let view = if self.studio.flying() {
             glam::Mat4::from_quat(self.camera_orientation().conjugate())
         } else {
             horizon_client::camera::view_matrix(view_yaw, view_pitch)
@@ -9569,7 +9531,7 @@ impl Game<'_> {
         } else {
             self.fov_degrees(camera_alpha as f32, camera.to_array())
         };
-        let camera_effects = fov::camera_effects_enabled(title, self.studio_freecam.active);
+        let camera_effects = fov::camera_effects_enabled(title, self.studio.flying());
         let bob = if !camera_effects {
             glam::Mat4::IDENTITY
         } else {
@@ -10074,7 +10036,7 @@ impl Game<'_> {
                 )
             )
         {
-            self.pad.keyboard_took_over = true;
+            self.input_keyboard_used();
         }
         if let WindowEvent::KeyboardInput { event, .. } = &event
             && event.state == ElementState::Pressed
@@ -10462,21 +10424,7 @@ impl Game<'_> {
                         let b = HudBatch::new([r.config.width, r.config.height]);
                         let previous = self.cursor;
                         self.cursor = (position.x as f32 / b.scale, position.y as f32 / b.scale);
-                        if self.screen == Screen::Playing
-                            && (self.studio_timeline.dragging_playhead
-                                || self.studio_timeline.dragging_keyframe.is_some())
-                        {
-                            let action = self.studio_timeline.handle_mouse_drag(
-                                self.cursor,
-                                b.width,
-                                &mut self.studio_freecam,
-                            );
-                            if matches!(
-                                action,
-                                horizon_client::studio::TimelineAction::KeyframeMoved
-                            ) {
-                                self.studio_camera_track_dirty = true;
-                            }
+                        if self.studio_mouse_dragged(b.width) {
                             return Ok(());
                         }
                         if self.screen_mouse_dragged(previous) {
@@ -10527,7 +10475,7 @@ impl Game<'_> {
                     }
                 }
                 WindowEvent::MouseWheel { .. }
-                    if self.screen == Screen::Playing && self.studio_replay.is_some() => {}
+                    if self.screen == Screen::Playing && self.replay.playing() => {}
                 WindowEvent::MouseWheel { delta, .. } => {
                     let (raw_x, raw_y) = match delta {
                         MouseScrollDelta::LineDelta(x, y) => (f64::from(x), f64::from(y)),
@@ -10804,90 +10752,7 @@ impl Game<'_> {
                 }
                 WindowEvent::MouseInput { state, button, .. } => {
                     let pressed = state == ElementState::Pressed;
-                    if !pressed && button == MouseButton::Left {
-                        let action = self.studio_timeline.handle_mouse_up();
-                        if !matches!(action, horizon_client::studio::TimelineAction::None) {
-                            self.handle_studio_timeline_action(action);
-                        }
-                    }
-                    if (self.studio_freecam.active || self.studio_replay.is_some())
-                        && button == MouseButton::Right
-                    {
-                        if let Some(renderer) = &self.renderer {
-                            let batch =
-                                HudBatch::new([renderer.config.width, renderer.config.height]);
-                            if self.studio_timeline.visible
-                                && self.cursor.1 >= batch.height - self.studio_timeline.height()
-                            {
-                                if pressed
-                                    && let Some(index) = self.studio_timeline.keyframe_at_cursor(
-                                        self.cursor,
-                                        batch.width,
-                                        batch.height,
-                                        &self.studio_freecam,
-                                    )
-                                {
-                                    if index < self.studio_freecam.track.keyframes.len() {
-                                        self.studio_freecam.track.keyframes.remove(index);
-                                        self.studio_camera_track_dirty = true;
-                                    }
-                                    self.studio_timeline.selected_keyframe = None;
-                                }
-                                return Ok(());
-                            }
-                        }
-                        if pressed {
-                            self.studio_topbar.close_dropdown();
-                            self.studio_rmb_down = true;
-                            self.capture(true);
-                            return Ok(());
-                        } else if self.studio_rmb_down {
-                            self.studio_rmb_down = false;
-                            self.capture(false);
-                            return Ok(());
-                        }
-                    }
-                    if pressed
-                        && button == MouseButton::Left
-                        && self.screen == Screen::Playing
-                        && (self.studio_replay.is_some() || self.studio_freecam.active)
-                    {
-                        let size = self
-                            .renderer
-                            .as_ref()
-                            .map(|renderer| [renderer.config.width, renderer.config.height])
-                            .unwrap_or([1, 1]);
-                        let batch = HudBatch::new(size);
-                        let had_open_menu = self.studio_topbar.open_menu.is_some();
-                        let topbar_action = self.studio_topbar.handle_mouse_click(
-                            self.cursor,
-                            batch.width,
-                            batch.height,
-                        );
-                        if !matches!(topbar_action, horizon_client::studio::TopBarAction::None) {
-                            self.handle_studio_topbar_action(topbar_action);
-                            return Ok(());
-                        }
-                        if had_open_menu || self.cursor.1 <= self.studio_topbar.height {
-                            return Ok(());
-                        }
-                        if self.studio_timeline.visible {
-                            let action = self.studio_timeline.handle_mouse_down(
-                                self.cursor,
-                                batch.width,
-                                batch.height,
-                                &self.studio_freecam,
-                            );
-                            if !matches!(action, horizon_client::studio::TimelineAction::None) {
-                                self.handle_studio_timeline_action(action);
-                                return Ok(());
-                            }
-                            if self.cursor.1 >= batch.height - self.studio_timeline.height() {
-                                return Ok(());
-                            }
-                        }
-                    }
-                    if self.screen == Screen::Playing && self.studio_replay.is_some() {
+                    if self.studio_mouse_input(pressed, button) {
                         return Ok(());
                     }
                     if matches!(self.screen, Screen::Inventory | Screen::Creative)
@@ -11357,24 +11222,7 @@ impl Game<'_> {
                     let between = now.saturating_duration_since(self.frame_end);
                     self.frame_ticks = elapsed.as_secs_f32() * 20.0;
                     self.previous = now;
-                    if self.studio_freecam.active
-                        && self.screen == Screen::Playing
-                        && !self.dialog_open()
-                    {
-                        let held = |key| f64::from(u8::from(self.keys.raw(&key)));
-                        let forward = held(KeyCode::KeyW) - held(KeyCode::KeyS);
-                        let strafe = held(KeyCode::KeyD) - held(KeyCode::KeyA);
-                        let vertical =
-                            held(KeyCode::KeyE) - held(KeyCode::KeyQ) + held(KeyCode::Space);
-                        let fast = self.keys.raw(&KeyCode::ControlRight);
-                        self.studio_freecam.update_flight_motion(
-                            forward,
-                            strafe,
-                            vertical,
-                            fast,
-                            elapsed.as_secs_f64().min(0.1),
-                        );
-                    }
+                    self.studio_fly(elapsed);
                     // Arrow-key camera controls belong to gameplay; chat and
                     // other screens use the same keys for their own navigation.
                     if self.screen == Screen::Playing
@@ -11404,8 +11252,7 @@ impl Game<'_> {
                     self.heal_hold_latches();
                     // For the hooks above the engine (the "I'm playing" ping): said when it changes.
                     horizon_hooks::engine::published(self.is_published());
-                    #[cfg(feature = "discord")]
-                    self.update_discord_presence();
+                    self.report_activity();
                     let steps = self.clock.advance(elapsed);
                     for _ in 0..steps {
                         let started = Instant::now();
@@ -11447,7 +11294,7 @@ impl Game<'_> {
                     self.extras_frame(elapsed);
                     self.extras_retry()?;
                     self.apply_mouse_look();
-                    self.pad_look(elapsed.as_secs_f32());
+                    self.input_look(elapsed.as_secs_f32());
                     self.advance_flight();
                     self.tick_world_icon();
                     let ticked = Instant::now();
@@ -11559,17 +11406,18 @@ impl Game<'_> {
                         server.set_legacy_rules(self.settings.extras.pvp.combat.rules);
                     }
                     self.clock.end_frame(self.pause);
-                    let mut consumed = false;
+                    let saved = self
+                        .renderer
+                        .as_mut()
+                        .map(|r| std::mem::take(&mut r.saved_screenshots))
+                        .unwrap_or_default();
+                    for saved in saved {
+                        self.finish_screenshot(saved);
+                    }
                     let finished = self
                         .renderer
                         .as_mut()
                         .and_then(|r| r.screenshot_result.take());
-                    if let Some(result) = &finished
-                        && self.ui.screenshot_message.is_some()
-                    {
-                        self.finish_screenshot(result);
-                        consumed = true;
-                    }
                     if let Some(result) = &finished
                         && let Some(reply) = self.pending_screenshot.take()
                     {
@@ -11582,7 +11430,6 @@ impl Game<'_> {
                             }
                             .to_string(),
                         );
-                        consumed = true;
                     }
                     if let Some(result) =
                         self.renderer.as_mut().and_then(|r| r.capture_result.take())
@@ -11591,12 +11438,6 @@ impl Game<'_> {
                         let value = result.unwrap_or_else(|e| serde_json::json!({ "error": e }));
                         let _ = reply.send(value.to_string());
                     }
-                    // A result nobody asked for was the world icon's
-                    // (`tick_world_icon`): a failure tries again a second
-                    // later, as `tryTakeScreenshotIfNeeded` does.
-                    if !consumed && let Some(Err(error)) = finished {
-                        log::warn!("Horizon: couldn't save the world icon: {error}");
-                    }
                     if rendered {
                         self.frame_stats.record(elapsed.as_secs_f32() * 1000.0);
                         self.debug_charts.frame_times.log(elapsed.as_nanos() as i64);
@@ -12157,16 +11998,8 @@ impl<'a> Game<'a> {
             entity_attachments: Default::default(),
             remote: None,
             realm_session: false,
-            studio_replay: None,
-            studio_freecam: Default::default(),
-            studio_timeline: Default::default(),
-            studio_topbar: Default::default(),
-            studio_rmb_down: false,
-            studio_camera_track_dirty: false,
-            studio_replay_previous_camera_type: None,
-            studio_replay_standalone: false,
-            last_replay_tick: None,
-            studio_virtual_tick_ms: 0.0,
+            replay: Default::default(),
+            studio: Default::default(),
             lan: None,
             integrated: None,
             level_shapes: Default::default(),
@@ -12665,10 +12498,8 @@ pub fn run_with() -> Result<()> {
     // horizon-ctl drives: those start in a source checkout and wrote the list there.
     if !options.offscreen && !synchronous_startup(&options) {
         let version = horizon_client::telemetry::version();
-        horizon_hooks::engine::started(&horizon_hooks::Started::new(&version));
-        // horizon-extras: the official server is Horizon's (docs/forking.md).
-        #[cfg(feature = "horizon-extras")]
-        horizon_client::official_servers::update(&horizon_client::logging::player_dir());
+        let game_dir = horizon_client::logging::player_dir();
+        horizon_hooks::engine::started(&horizon_hooks::Started::new(&version, &game_dir));
     }
     mods::register_components(&vanilla_root)?;
     mods::register_standalone_models();
@@ -12696,15 +12527,8 @@ pub fn run_with() -> Result<()> {
     if options.execution_role.is_client() {
         narrator::start(&early_settings);
     }
-    // "Playing Horizon" on Discord: never for a server; an automated run only talks to a test's fake Discord.
-    #[cfg(feature = "discord")]
-    if options.dedicated.is_none() {
-        let automated = options.benchmark.is_some()
-            || options.offscreen
-            || options.frames.is_some()
-            || options.world_frames.is_some();
-        horizon_client::discord_presence::start(early_settings.extras.discord_presence, automated);
-    }
+    // A game window's hooks (Discord's presence): never for a server.
+    activity::client_started(&options, &early_settings);
     // Snapshots of derived tables live in the game folder, never beside the
     // shared resources.
     Behaviours::set_cache_dir(std::env::current_dir()?.join(".horizon-cache"));

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

@@ -0,0 +1,76 @@
+//! What the player is doing, for the hooks above the engine (`Hooks::activity`: the Horizon
+//! layer's Discord presence shows it).
+use super::*;
+use horizon_client::command::args::GameMode;
+use horizon_hooks::{Activity, Client, Dimension, Play};
+
+/// At startup, for a game window (never a dedicated server's): the player's first activity, then
+/// `Hooks::client_started`.
+pub(super) fn client_started(options: &Options, settings: &Settings) {
+    if options.dedicated.is_some() {
+        return;
+    }
+    let automated = options.benchmark.is_some()
+        || options.offscreen
+        || options.frames.is_some()
+        || options.world_frames.is_some();
+    // The Discord switch's state is the first thing the presence hears, so nothing is sent with
+    // it off.
+    horizon_hooks::engine::activity(match settings.extras.discord_presence {
+        true => Activity::Menus,
+        false => Activity::Hidden,
+    });
+    horizon_hooks::engine::client_started(&Client::new(automated));
+}
+
+impl Game<'_> {
+    /// Each frame: only a change reaches the hooks.
+    pub(super) fn report_activity(&self) {
+        // One status per computer: P1's, not a splitscreen player's.
+        if self.options.split_guest {
+            return;
+        }
+        horizon_hooks::engine::activity(self.activity());
+    }
+    fn activity(&self) -> Activity {
+        if !self.settings.extras.discord_presence {
+            return Activity::Hidden;
+        }
+        if self.title.is_some() {
+            return Activity::Menus;
+        }
+        let max = horizon_client::lan::MAX_PLAYERS;
+        let play = if let Some(host) = &self.lan {
+            Play::Hosting {
+                players: 1 + host.hub.guests.len(),
+                max,
+            }
+        } else if let Some(server) = &self.integrated {
+            match (server.published(), &self.remote) {
+                (Some(_), Some(remote)) => Play::Hosting {
+                    players: remote.player_count(),
+                    max,
+                },
+                _ => Play::Singleplayer,
+            }
+        } else if self.remote.is_some() {
+            Play::Multiplayer
+        } else {
+            Play::Singleplayer
+        };
+        Activity::World {
+            play,
+            dimension: match self.dim {
+                Dim::Overworld => Dimension::Overworld,
+                Dim::Nether => Dimension::Nether,
+                Dim::End => Dimension::End,
+            },
+            mode: match self.mode {
+                GameMode::Survival => horizon_hooks::GameMode::Survival,
+                GameMode::Creative => horizon_hooks::GameMode::Creative,
+                GameMode::Adventure => horizon_hooks::GameMode::Adventure,
+                GameMode::Spectator => horizon_hooks::GameMode::Spectator,
+            },
+        }
+    }
+}

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

@@ -848,34 +848,20 @@ impl Game<'_> {
             self.armor_stands[i].last_hit = time;
             return true;
         }
-        // brokenByPlayer: the stand item, then brokenByAnything: the equipment.
-        let a = self.armor_stands.remove(i);
-        let (width, height) = stand_box(&a);
-        self.audio
-            .play("minecraft:entity.armor_stand.break", Some(at), 1.0, 1.0);
-        self.show_breaking_particles(at, f64::from(width), f64::from(height));
-        let center = [at[0], at[1] + if a.small { 0.4875 } else { 0.9875 }, at[2]];
-        let stand = ItemStack {
-            item: Arc::from("minecraft:armor_stand"),
-            count: 1,
-            damage: 0,
-            extra: None,
-        };
-        self.spawn_item(stand, center, [0.0; 3], 10);
-        for stack in a.equipment.into_iter().flatten() {
-            let r = &mut self.world.random;
-            let v = [
-                f64::from(r.next_float()) * 0.2 - 0.1,
-                0.2,
-                f64::from(r.next_float()) * 0.2 - 0.1,
-            ];
-            self.spawn_item(stack, center, v, 10);
+        // brokenByPlayer: the stand item, with the stand's name, pops at its
+        // block, then brokenByAnything: the loot table and the equipment.
+        let (width, height) = stand_box(&self.armor_stands[i]);
+        let p = self.armor_stands[i].position;
+        let pos = [p.x.floor() as i32, p.y.floor() as i32, p.z.floor() as i32];
+        let mut stand = ItemStack::new("minecraft:armor_stand", 1);
+        if let Some(name) = &self.armor_stands[i].custom_name {
+            stand.data_mut().custom_name =
+                Some(horizon_client::scoreboard::component_tag(&name.component()));
         }
+        self.pop_resource(pos, stand);
         // ArmorStand.kill(level, the causing entity), after the drops.
-        self.stand_game_event("minecraft:entity_die", at, by);
-        self.world
-            .modified
-            .insert(((at[0].floor() as i32) >> 4, (at[2].floor() as i32) >> 4));
+        self.break_armor_stand_with_source(i, by);
+        self.show_breaking_particles(at, f64::from(width), f64::from(height));
         true
     }
     /// `Entity.gameEvent(event, attributedTo)` for a stand at `at`: the
@@ -1202,6 +1188,8 @@ impl Game<'_> {
         let a = self.armor_stands.remove(i);
         let at = [a.position.x, a.position.y, a.position.z];
         let a_id = a.id;
+        self.audio
+            .play("minecraft:entity.armor_stand.break", Some(at), 1.0, 1.0);
         // brokenByAnything's dropAllDeathLoot, before the equipment.
         if !a.small && self.ui.rules.bool("mob_drops") {
             self.armor_stand_death_loot(at, a.fire_ticks > 0);
@@ -1210,8 +1198,6 @@ impl Game<'_> {
         for stack in drops {
             self.pop_resource(pos, stack);
         }
-        self.audio
-            .play("minecraft:entity.armor_stand.break", Some(at), 1.0, 1.0);
         self.entity_killed_event_by(at, source.or(Some(super::commands::Target::Stand(a_id))));
         self.world.modified.insert((pos[0] >> 4, pos[2] >> 4));
     }

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

@@ -42,12 +42,25 @@ impl Game<'_> {
         self.trial_spawner_tick_positions.clear();
         self.item_columns = Some(Default::default());
         self.pass_mobs = Some(Default::default());
-        for slot in self.world.block_entity_tickers().iter().copied() {
+        let tickers = self.world.block_entity_tickers();
+        let mut last_chunk = (i32::MIN, i32::MIN);
+        let mut last_chunk_ticking = false;
+        for slot in tickers.iter().copied() {
             let pos = slot.0;
+            let chunk = (pos.0 >> 4, pos.2 >> 4);
+            let chunk_ticking = if chunk == last_chunk {
+                last_chunk_ticking
+            } else {
+                last_chunk = chunk;
+                last_chunk_ticking = ticking(pos.0, pos.2);
+                last_chunk_ticking
+            };
+            if !chunk_ticking {
+                continue;
+            }
             // Ticks before this one can remove it (`TickingBlockEntity.isRemoved`).
             if self.world.block_entities.is_asleep(&pos)
                 || !self.world.block_entities.is_live(slot)
-                || !ticking(pos.0, pos.2)
                 || !self.border.contains(f64::from(pos.0), f64::from(pos.2))
             {
                 continue;
@@ -210,8 +223,14 @@ impl Game<'_> {
     /// (`ServerLevel.areEntitiesLoaded`).
     pub(super) fn block_ticking_area(&self) -> impl Fn(i32, i32) -> bool + use<> {
         let levels = self.tickets.levels();
-        let pending = self.world.entities_pending.clone();
-        move |x, z| levels.block_ticking_at(x, z) && !pending.contains(&(x >> 4, z >> 4))
+        let has_pending = !self.world.entities_pending.is_empty();
+        let pending = has_pending.then(|| self.world.entities_pending.clone());
+        move |x, z| {
+            levels.block_ticking_at(x, z)
+                && pending
+                    .as_ref()
+                    .is_none_or(|p| !p.contains(&(x >> 4, z >> 4)))
+        }
     }
     /// `DaylightDetectorBlock.tickEntity` of the detector at `pos`.
     fn tick_daylight_detector(&mut self, pos: Pos) {

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

@@ -1608,6 +1608,16 @@ impl Game<'_> {
         }
     }
 }
+/// `LecternBlock.getAnalogOutputSignal`'s `HAS_BOOK` check.
+pub(super) fn has_book_state(
+    registry: &'static horizon_world::registry::BlockRegistry,
+    state: horizon_world::registry::BlockStateId,
+) -> bool {
+    registry
+        .state(state)
+        .is_some_and(|s| s.properties.get("has_book").is_some_and(|v| v == "true"))
+}
+
 /// `LecternBlockEntity.getRedstoneSignal`.
 pub(super) fn lectern_signal(world: &horizon_client::world::World, pos: BlockPos) -> Option<i32> {
     match world.block_entities.get(&(pos.x, pos.y, pos.z)) {
@@ -1721,6 +1731,7 @@ mod lectern_signal_tests {
         items::ItemStack,
     };
     use horizon_core::position::BlockPos;
+    use horizon_world::level::LevelAccess;
     use horizon_world::registry::BlockStateId;
 
     fn signal(game: &mut super::Game<'_>, book: Option<ItemStack>, page: i32) -> i32 {
@@ -1738,6 +1749,55 @@ mod lectern_signal_tests {
         lectern_signal(&game.world, BlockPos::new(key.0, key.1, key.2)).unwrap()
     }
 
+    /// `LecternBlock.getAnalogOutputSignal` reads the block entity only while
+    /// the state's `HAS_BOOK` is true.
+    #[test]
+    #[ignore = "needs prepared resources in HORIZON_TEST_RESOURCES"]
+    fn a_lectern_without_the_has_book_state_feeds_no_comparator() {
+        let mut game = server_game();
+        let key = (8, 64, 8);
+        let state = game
+            .pack
+            .assets
+            .registry
+            .default_state("minecraft:lectern")
+            .unwrap();
+        game.world.set(key.0, key.1, key.2, state).unwrap();
+        game.world.block_entities.insert(
+            key,
+            BlockEntity::Lectern(Lectern {
+                book: Some(ItemStack::new("minecraft:writable_book", 1)),
+                page: 0,
+            }),
+        );
+        let signal = |game: &mut super::Game<'_>, state| {
+            game.with_level(|_, level, _| {
+                level.block_entity_analog_signal(
+                    BlockPos::new(key.0, key.1, key.2),
+                    state,
+                    horizon_core::geometry::Direction::North,
+                )
+            })
+        };
+        assert_eq!(
+            signal(&mut game, state),
+            0,
+            "the block state says the lectern holds no book"
+        );
+        let registry = game.pack.assets.registry;
+        let mut with_book = registry.state(state).unwrap().clone();
+        with_book
+            .properties
+            .insert("has_book".into(), "true".into());
+        let with_book = registry.id(&with_book).unwrap();
+        game.world.set(key.0, key.1, key.2, with_book).unwrap();
+        assert_eq!(
+            signal(&mut game, with_book),
+            15,
+            "with HAS_BOOK the book's page signal"
+        );
+    }
+
     /// `LecternBlockEntity.getRedstoneSignal`: `floor(page / (pageCount - 1)
     /// * 14) + (hasBook() ? 1 : 0)`. `hasBook()` asks for a book-content
     /// component, so a stack that only sits in the lectern (a non-book item a

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

@@ -255,8 +255,8 @@ pub struct UiState {
     /// What this frame's HUD shows that Horizon's overlays keep clear of (`Game::hud_room`),
     /// set by `hud_layers` before anything draws.
     pub room: horizon_client::hud_kit::room::Room,
-    /// Path of an F2 screenshot waiting for its frame.
-    pub screenshot_message: Option<std::path::PathBuf>,
+    /// F2 screenshots not written yet: each reports in chat once its PNG is.
+    pub screenshot_messages: Vec<std::path::PathBuf>,
     /// The options screens.
     pub options: horizon_client::options_ui::OptionsUi,
     /// The prepared resources before resource packs are layered on.
@@ -1982,15 +1982,17 @@ impl Game<'_> {
         if std::fs::create_dir_all(&dir).is_err() {
             return None;
         }
-        let name = screenshot_name(&dir);
+        // A screenshot still being written has no file yet: its name is taken all the same.
+        let name = screenshot_name(&dir, &self.ui.screenshot_messages);
         let renderer = self.renderer.as_mut()?;
         let path = dir.join(name);
         renderer.screenshot = Some(horizon_client::gfx::ScreenshotRequest {
             path: path.clone(),
             size: None,
             scaled: true,
+            background: true,
         });
-        self.ui.screenshot_message = Some(path.clone());
+        self.ui.screenshot_messages.push(path.clone());
         Some(path)
     }
     /// `Minecraft.handleGlobalKeyPress`'s screenshot branch: the
@@ -2014,12 +2016,23 @@ impl Game<'_> {
         self.take_screenshot();
         true
     }
-    /// After a frame: report a finished F2 screenshot in chat.
-    pub(super) fn finish_screenshot(&mut self, result: &std::result::Result<[u32; 2], String>) {
-        let Some(path) = self.ui.screenshot_message.take() else {
+    /// A screenshot written on its thread: F2's reports in chat. Any other was the world
+    /// icon's (`tick_world_icon`): a failure tries again a second later, as
+    /// `tryTakeScreenshotIfNeeded` does.
+    pub(super) fn finish_screenshot(&mut self, saved: horizon_client::gfx::SavedScreenshot) {
+        let Some(at) = self
+            .ui
+            .screenshot_messages
+            .iter()
+            .position(|p| *p == saved.path)
+        else {
+            if let Err(error) = saved.result {
+                log::warn!("Horizon: couldn't save the world icon: {error}");
+            }
             return;
         };
-        let message = match result {
+        let path = self.ui.screenshot_messages.remove(at);
+        let message = match &saved.result {
             Ok(_) => {
                 log::info!("Saved screenshot to {}", path.display());
                 let name = path.file_name().unwrap_or_default().to_string_lossy();
@@ -2055,7 +2068,7 @@ fn chat_box_text(text: &str) -> String {
         .filter(|&ch| ch >= ' ' && ch != '\u{7f}' && ch != '§')
         .collect()
 }
-pub fn screenshot_name(dir: &std::path::Path) -> String {
+pub fn screenshot_name(dir: &std::path::Path, pending: &[std::path::PathBuf]) -> String {
     // Util.getFilenameFormattedDateTime: the local date and time.
     let base = chrono::Local::now().format("%Y-%m-%d_%H.%M.%S").to_string();
     let mut n = 1;
@@ -2065,7 +2078,8 @@ pub fn screenshot_name(dir: &std::path::Path) -> String {
         } else {
             format!("{base}_{n}.png")
         };
-        if !dir.join(&name).exists() {
+        let path = dir.join(&name);
+        if !path.exists() && !pending.contains(&path) {
             return name;
         }
         n += 1;
@@ -2107,6 +2121,25 @@ mod tests {
         assert!(should_discard_draft(ChatExit::Done, true));
     }
 
+    /// `Screenshot.getFile` picks the first free name of the second; an F2
+    /// screenshot still being written on its thread has no file yet, so a
+    /// second press in the same second takes the next name, not the same one.
+    #[test]
+    fn a_screenshot_being_written_keeps_its_name() {
+        let dir = std::env::temp_dir().join(format!("horizon-shots-{}", std::process::id()));
+        std::fs::create_dir_all(&dir).unwrap();
+        let first = screenshot_name(&dir, &[]);
+        let second = screenshot_name(&dir, &[dir.join(&first)]);
+        assert_ne!(first, second);
+        // Unless the clock turned to the next second in between.
+        let same_second = second.starts_with(first.trim_end_matches(".png"));
+        assert!(
+            !same_second || second == first.replace(".png", "_2.png"),
+            "{second}"
+        );
+        std::fs::remove_dir_all(&dir).unwrap();
+    }
+
     #[test]
     fn resource_ids_are_listed_once_per_root() {
         let root = std::env::temp_dir().join(format!("horizon-ids-{}", std::process::id()));

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

@@ -3831,12 +3831,9 @@ impl Game<'_> {
                     return;
                 }
                 g.spawn = None;
-                g.respawn_config = Some(super::respawn_anchor::RespawnConfig {
-                    dim: level,
-                    pos,
-                    yaw,
-                    forced: true,
-                });
+                g.respawn_config = Some(super::respawn_anchor::RespawnConfig::forced(
+                    level, pos, yaw, pitch,
+                ));
             });
         }
         let dim = Text::literal(self.dim.id());

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

@@ -644,7 +644,7 @@ impl Game<'_> {
                     .into());
                 }
                 if arg(2)? != "up" {
-                    self.pad.keyboard_took_over = true;
+                    self.input_keyboard_used();
                 }
                 // The command confirmation takes the keys; none go past it.
                 if self.command_prompt.is_some() {
@@ -800,7 +800,7 @@ impl Game<'_> {
                 // controller still holding one keeps it.
                 let options = [self.settings.toggle_crouch, self.settings.toggle_sprint];
                 for (slot, name) in [(0, "key.sneak"), (1, "key.sprint")] {
-                    if !self.pad.holds_action(&self.settings.controller, name) {
+                    if !self.input_holds(name) {
                         self.toggles.key(
                             slot,
                             horizon_client::keymapping::KeyAction::Release,
@@ -1039,6 +1039,7 @@ impl Game<'_> {
                     path: path.trim().into(),
                     size: None,
                     scaled: false,
+                    background: false,
                 });
                 self.pending_screenshot = Some(reply.clone());
                 Ok(None)

crates/horizon-client/src/game/cosmetics/emotes.rs

@@ -10,6 +10,7 @@ use horizon_client::mobs::Mob;
 use horizon_client::mobs::anim::BodyPose;
 use horizon_cosmetics::account::OwnedEmote;
 use horizon_cosmetics::{Item, Playing, Slot};
+use horizon_hooks::players::PlayerModels;
 use std::sync::Arc;
 
 /// How far the player may drift (blocks) before the emote stops: a nudge, not a step.
@@ -37,10 +38,15 @@ pub(in crate::game) struct Emotes {
 
 impl Emotes {
     /// The emote to tell the service about, while it plays: its id and whether it loops.
-    pub(in crate::game) fn sending(&self) -> Option<(String, bool)> {
+    pub(in crate::game) fn sending(&self) -> Option<(&str, bool)> {
         let p = self.playing.as_ref().filter(|p| p.stop.is_none())?;
         let looping = p.item.emote.as_ref().is_some_and(|e| e.looping);
-        Some((p.item.id.clone(), looping))
+        Some((&p.item.id, looping))
+    }
+
+    /// When the emote that pulled the camera back started (the own model's age), while it plays.
+    pub(in crate::game) fn pull(&self) -> Option<f32> {
+        self.camera_from.and(self.playing.as_ref()).map(|p| p.start)
     }
 }
 
@@ -59,23 +65,43 @@ impl BodyPose for EmotePose {
     }
 }
 
-/// The emote `m` plays, if any.
-pub(in crate::game) fn playing(m: &Mob) -> Option<&Playing> {
-    let any: &dyn std::any::Any = &**m.emote.as_ref()?;
+/// The emote a model's pose plays, if it is one.
+pub(in crate::game) fn pose_playing(pose: Option<&Arc<dyn BodyPose>>) -> Option<&Playing> {
+    let any: &dyn std::any::Any = &**pose?;
     any.downcast_ref::<EmotePose>().map(|e| &e.0)
 }
 
-/// Makes `m` play `next`, unless it plays that already (a new one allocates).
-pub(in crate::game) fn set_playing(m: &mut Mob, next: Option<Playing>) {
-    let same = match (playing(m), &next) {
+/// The pose that plays `next` where `now` is laid, unless it plays that already (None: keep
+/// it; a new one allocates).
+fn replaced(
+    now: Option<&Arc<dyn BodyPose>>,
+    next: Option<Playing>,
+) -> Option<Option<Arc<dyn BodyPose>>> {
+    let same = match (pose_playing(now), &next) {
         (None, None) => true,
         (Some(a), Some(b)) => {
             Arc::ptr_eq(&a.item, &b.item) && a.start == b.start && a.stop == b.stop
         }
         _ => false,
     };
-    if !same {
-        m.emote = next.map(|p| Arc::new(EmotePose(p)) as Arc<dyn BodyPose>);
+    (!same).then(|| next.map(|p| Arc::new(EmotePose(p)) as Arc<dyn BodyPose>))
+}
+
+/// Makes `m` play `next`, unless it plays that already.
+pub(in crate::game) fn set_playing(m: &mut Mob, next: Option<Playing>) {
+    if let Some(pose) = replaced(m.emote.as_ref(), next) {
+        m.emote = pose;
+    }
+}
+
+/// Makes model `id` play `next`, unless it plays that already.
+pub(in crate::game) fn set_model_playing(
+    models: &mut dyn PlayerModels,
+    id: u32,
+    next: Option<Playing>,
+) {
+    if let Some(pose) = replaced(models.body_pose(id), next) {
+        models.set_body_pose(id, pose);
     }
 }
 
@@ -229,7 +255,7 @@ impl Game<'_> {
         }
     }
 
-    /// Once a tick: my emote, then the other players'.
+    /// Once a tick: my emote (the others' are `cosmetics::Seat::tick`'s, a hook's).
     pub(in crate::game) fn tick_emotes(&mut self) {
         if let Some(done) = self
             .cosmetics
@@ -250,20 +276,6 @@ impl Game<'_> {
             }
         }
         self.tick_emote();
-        self.tick_others_emotes();
-    }
-
-    /// How far the camera stands back while an emote pulls it (1: the usual distance): it eases
-    /// out over the emote's first quarter second.
-    pub(in crate::game) fn emote_camera_pull(&self, partial: f32) -> f32 {
-        let (Some(p), Some(m)) = (&self.cosmetics.emotes.playing, &self.player_model) else {
-            return 1.0;
-        };
-        if self.cosmetics.emotes.camera_from.is_none() {
-            return 1.0;
-        }
-        let t = ((m.age as f32 + partial - p.start) / 5.0).clamp(0.0, 1.0);
-        0.35 + 0.65 * t * t * (3.0 - 2.0 * t)
     }
 }
 

crates/horizon-client/src/game/cosmetics/fx.rs

@@ -314,8 +314,7 @@ impl Game<'_> {
             light = FULL_LIGHT;
         }
         let mut poses = self.cosmetics.poses.borrow_mut();
-        let poses = &mut poses.1;
-        self.pose_companion(item, m, alpha, poses, &model);
-        self.cosmetics_model(&model, matrix, poses, uv, light, false, None, out);
+        self.pose_companion(item, m, alpha, &mut poses, &model);
+        self.cosmetics_model(&model, matrix, &poses, uv, light, false, None, out);
     }
 }

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

@@ -9,7 +9,7 @@ impl Game<'_> {
     pub(super) fn mapped_key_down(&self, mapping: &str) -> bool {
         keybinds::key_code(self.settings.keys.get(mapping))
             .is_some_and(|k| self.physical_keys.contains(&k))
-            || self.pad.holds_action(&self.settings.controller, mapping)
+            || self.input_holds(mapping)
     }
 
     /// `CreativeModeInventoryScreen.selectTab` on the HOTBAR tab: each saved

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

@@ -2317,7 +2317,7 @@ impl Game<'_> {
             a.spawn_velocity = Some(p.velocity);
             a.spawn_rot = Some((p.pitch, p.yaw));
         }
-        self.creatures.projectiles.push(p);
+        self.creatures.projectiles.put_back(p);
         self.native_projectile_launch(player, &name, id, kind);
     }
     /// `MushroomCow.shear`'s `sendParticles(EXPLOSION, x, getY(0.5), z, 1, 0, 0, 0, 0)`:
@@ -6949,7 +6949,7 @@ impl Game<'_> {
             {
                 m.heal(25.0);
                 consume = true;
-                sound = Some("entity.iron_golem.repair");
+                eat = Some(("entity.iron_golem.repair", 1.0, m.golem_repair_pitch()));
             }
             Species::Creeper if creeper_igniter => {
                 m.extra.flag = true;

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

@@ -280,25 +280,18 @@ impl Game<'_> {
                 self.spin_attack_geometry(mob, camera, alpha as f32, packed, out);
                 self.stuck_in_body_geometry(mob, mob.id as i32, camera, alpha as f32, packed, out);
             }
-            // Cosmetics (game/cosmetics.rs), posed on the GPU with the mob's own jobs: culled
-            // with it.
+            // What crates draw on players and mannequins (`game/player_hooks.rs`: cosmetics),
+            // posed on the GPU with the mob's own jobs: culled with it.
             if !layers_only
-                && super::super::cosmetics::enabled()
+                && horizon_hooks::engine::any()
                 && (is_player || &*mob.kind.id == "minecraft:mannequin")
             {
                 let mark = self.skin_frame.borrow().mark();
                 let base = horizon_client::mobs::render::base_transform(mob, alpha as f32, camera);
                 let gpu = skinning;
-                if let Some((lo, hi)) = self.cosmetics_geometry(
-                    mob,
-                    false,
-                    base,
-                    Some(camera),
-                    alpha as f32,
-                    packed,
-                    gpu,
-                    out,
-                ) {
+                if let Some((lo, hi)) =
+                    self.player_layers_geometry(mob, base, camera, alpha as f32, packed, gpu, out)
+                {
                     skinned = Some(match skinned {
                         Some((first, Some((l, h)))) => (first, Some((l.min(lo), h.max(hi)))),
                         Some((first, None)) => (first, Some((lo, hi))),

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

@@ -1,49 +0,0 @@
-//! What the player is doing, for Discord Rich Presence (`horizon_client::discord_presence`).
-use super::*;
-use horizon_client::discord_presence::{self as presence, Dimension, Play, Status};
-
-impl Game<'_> {
-    /// Each frame: only a change reaches the presence thread.
-    pub(super) fn update_discord_presence(&self) {
-        // One Discord status per computer: P1's, not a splitscreen player's.
-        if self.options.split_guest {
-            return;
-        }
-        presence::set(self.discord_status());
-    }
-    fn discord_status(&self) -> Status {
-        if !self.settings.extras.discord_presence {
-            return Status::Off;
-        }
-        if self.title.is_some() {
-            return Status::Menus;
-        }
-        let play = if let Some(host) = &self.lan {
-            Play::Hosting {
-                players: 1 + host.hub.guests.len(),
-                max: horizon_client::lan::MAX_PLAYERS,
-            }
-        } else if let Some(server) = &self.integrated {
-            match (server.published(), &self.remote) {
-                (Some(_), Some(remote)) => Play::Hosting {
-                    players: remote.player_count(),
-                    max: horizon_client::lan::MAX_PLAYERS,
-                },
-                _ => Play::Singleplayer,
-            }
-        } else if self.remote.is_some() {
-            Play::Multiplayer
-        } else {
-            Play::Singleplayer
-        };
-        Status::World {
-            play,
-            dimension: match self.dim {
-                Dim::Overworld => Dimension::Overworld,
-                Dim::Nether => Dimension::Nether,
-                Dim::End => Dimension::End,
-            },
-            mode: self.mode,
-        }
-    }
-}

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

@@ -353,7 +353,7 @@ impl Game<'_> {
             let found =
                 self.find_respawn_and_use(config, op["consume"].as_bool().unwrap_or(true))?;
             used.push(match found {
-                Some((p, yaw)) => format!(
+                Some((p, yaw, _pitch)) => format!(
                     "respawn {} {} {} {}",
                     num(p.x),
                     num(p.y),
@@ -579,6 +579,7 @@ impl Game<'_> {
                 dim: self.dim,
                 pos: [p(0), p(1), p(2)],
                 yaw: 0.0,
+                pitch: 0.0,
                 forced: false,
             });
         }

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

@@ -739,7 +739,8 @@ impl Game<'_> {
         // anchor puts the player, facing it; else onto the spawn column.
         let mut target = target;
         if let Some(c) = self.respawn_config.filter(|c| c.dim == self.dim) {
-            if let Some((at, yaw)) = self.find_respawn_and_use(c, false)? {
+            // This existing owner transition adapter carries yaw only; its pitch path remains open.
+            if let Some((at, yaw, _pitch)) = self.find_respawn_and_use(c, false)? {
                 return Ok(Some((at, Some(yaw))));
             }
             target = fallback_spawn(self.spawn, self.level.world_spawn);

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

@@ -1008,7 +1008,10 @@ impl Game<'_> {
                 p.position.z - center[2],
             ];
             let distance = (d[0] * d[0] + d[1] * d[1] + d[2] * d[2]).sqrt();
-            self.pad_rumble(horizon_client::gamepad::Rumble::Explosion { distance, radius });
+            self.input_feedback(horizon_client::input_source::Feedback::Explosion {
+                distance,
+                radius,
+            });
         }
         // Explosion.explode: the blast is heard.
         let ctx = horizon_client::sculk::Context::default();

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

@@ -70,9 +70,10 @@ fn overworld_spawnpoint_is_validated_at_both_player_blocks() {
             assert_eq!(actual.is_some(), allowed, "{block} at height {height}");
             assert_eq!(game.respawn_config.is_some(), allowed);
             assert_eq!(game.level.world_spawn, Some([0, 80, 0]));
-            if let Some((at, yaw)) = actual {
+            if let Some((at, yaw, pitch)) = actual {
                 assert_eq!(at, Vec3::new(5.5, 64.1, 5.5));
                 assert_eq!(yaw, 0.0);
+                assert_eq!(pitch.to_bits(), 0.0f32.to_bits());
             }
         }
     }

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

@@ -135,8 +135,8 @@ impl Game<'_> {
     }
     /// `Camera.calculateFov` with `modifyFovBasedOnDeathOrFluid`.
     pub(super) fn fov_degrees(&self, partial: f32, camera: [f64; 3]) -> f32 {
-        if self.studio_freecam.active {
-            return self.studio_freecam.fov.clamp(1.0, 179.0);
+        if self.studio.flying() {
+            return self.studio.freecam.fov.clamp(1.0, 179.0);
         }
         let fov = self.view.calculate_fov(
             partial,