Pages v2: text fields, and a page in the title screen's Friends icon slot

horizon_hooks::pages gains Row::Field (Row::field(label, text).max(n)), vanilla's EditBox on a page drawn as its own screen, with Act::Edit (each change, before any other act or redraw reaches the page) and Act::Submit (Enter); Place::Title, the title screen's Friends icon slot, unchanged in place and look; Page::back, the label of the button that leaves such a page; and pages::connect, for a Title page to join a server. The icon opens the first Title page as multiplayer::Screen::Page, a form laid out as Join a Friend (multiplayer/page.rs); its fields go through the title screen's caret like every field of its own (focus, typing, caret keys, selection, copy, paste, the max length), Tab walks fields then buttons. Without a Title page the icon opens Join a Friend while a resolver is registered, else it stays inactive. The options shell skips fields. title.rs loses lines. Co-Authored-By: Claude Opus 5.5 <[email protected]>
The title screen's Friends icon is inactive without an invite-code resolver (spec #14167 step 4)
2026-11-10 02:21:33 -10:00 · 2026-11-09 23:11:27 +01:00 · 2026-11-09 22:45:31 +01:00 · 2026-11-09 22:35:02 +01:00 · 2026-11-09 22:32:39 +01:00 · 2026-11-09 22:25:53 +01:00
419 changed files with 15679 additions and 11619 deletions
@@ -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)
@@ -186,7 +186,7 @@ state stays separate from the library tests. This compiles gameplay twice for ex
 | Resource packs | L: `packs.rs` + `packs/`, `pack_screen.rs`, `atlas_sources.rs`, `sprites.rs`, `mipmap.rs`, `model_library.rs`, `font.rs`, `mobs/cem.rs` + `mobs/cem_anim.rs` (OptiFine/EMF entity models and their animations); `horizon-client-core/src/lang.rs`; crates `horizon-assets`, `horizon-optifine`; G: `packs.rs` |
 | Agent control | L: `control.rs` (socket), `bin/horizon-ctl/`; G: `control.rs`, `agent.rs`, `events.rs`, `ui_control.rs` ([docs/agent-control.md](docs/agent-control.md)) |
 | Mods | crate `horizon-mods`; G: `mods.rs`; L: `mod_content.rs`, `mod_list.rs` |
-| Horizon extras, settings | L: `extras.rs`, `graphics.rs`, `settings.rs`, `minimap.rs`; G: `extras.rs` + `extras/` (each extra's glue: `mouse_tweaks.rs`, `sorting.rs`, `pvp.rs`, `reconnect.rs`), `options.rs` |
+| Horizon extras, settings | L: `extras.rs`, `graphics.rs`, `settings.rs`, `minimap.rs`; G: `extras.rs`, `tweaks.rs`, `options.rs` |

 ## How `Game` is organised

@@ -13,6 +13,14 @@ else (videos, Discord and other community material) lives elsewhere.
 suggest something. A pull request for a roadmap item carries its `roadmap:<id>` label; ideas go to the suggestion
 queue (the hub, or `/suggest` on Discord) rather than to issues, which are for bugs.

+**Mod-related pull requests go to [arismoko/horizon](https://github.com/arismoko/horizon)**, the fork that carries the
+mod API and reviews and merges that work. That covers the mod API, native hooks and events for mods, native mods,
+content mods (`.hmod`), mixins, wasm mods, `cargo horizon-mod`, `horizon-mods`, mod builds and the registry, and
+their docs ([mods](docs/mods.md), [native mods](docs/native-mods.md)). Open the pull request there from your usual
+branch. Mod-related pull requests opened here are closed with a pointer to it. Engine extension points that Horizon's
+own crates register (the [layer split](docs/layers.md)), resource and shader pack formats, and gameplay fixes stay
+here.
+
 ## Build it

 - **Prerequisites:** Rust (stable), Python 3.10+, JDK 25, and on Linux the ALSA and udev headers
@@ -190,3 +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).
@@ -1418,6 +1418,7 @@ dependencies = [
 name = "horizon-chat-filter"
 version = "0.1.0"
 dependencies = [
+ "horizon-server-files",
 "serde",
 "serde_json",
 "toml",
@@ -1528,7 +1529,6 @@ dependencies = [
 "horizon-client-render",
 "horizon-command",
 "horizon-core",
- "horizon-friends",
 "horizon-hdr",
 "horizon-hooks",
 "horizon-items",
@@ -1592,7 +1592,6 @@ dependencies = [
 "horizon-optifine",
 "horizon-polytone",
 "horizon-protocol",
- "horizon-render-pipeline",
 "horizon-shader-api",
 "horizon-shaders",
 "horizon-system",
@@ -1668,6 +1667,7 @@ dependencies = [
 "getrandom 0.3.4",
 "hkdf",
 "horizon-addresses",
+ "horizon-platform",
 "if-addrs",
 "serde",
 "serde_json",
@@ -1793,13 +1793,24 @@ dependencies = [
 name = "horizon-official"
 version = "0.1.0"
 dependencies = [
+ "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"
@@ -1891,10 +1902,6 @@ dependencies = [
 "ring",
 ]

-[[package]]
-name = "horizon-render-pipeline"
-version = "0.1.0"
-
 [[package]]
 name = "horizon-server"
 version = "0.1.0"
@@ -1957,7 +1964,6 @@ version = "0.1.0"
 dependencies = [
 "half",
 "horizon-core",
- "horizon-render-pipeline",
 "naga",
 "png",
 "zip",
@@ -34,6 +34,7 @@ members = [
    "crates/horizon-game",
    "crates/horizon-official",
    "crates/horizon-heartbeat",
+    "crates/horizon-official-servers",
    "crates/horizon-bench",
    "crates/horizon-friends",
    "crates/horizon-relay",
@@ -43,7 +44,6 @@ members = [
    "crates/cargo-horizon-mod",
    "crates/horizon-port-pack",
    "crates/horizon-shaders",
-    "crates/horizon-render-pipeline",
    "crates/horizon-optifine",
    "crates/horizon-polytone",
    "crates/horizon-shader-api",
@@ -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.
@@ -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.
@@ -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";
@@ -7,6 +7,8 @@ rust-version.workspace = true
 description = "The dedicated server's chat filter: its [chat_filter] settings, the slur list's matcher and the mutes, with no game state (docs/chat-filter.md)"

 [dependencies]
+# The moderation durations, shared with `/tempban`.
+horizon-server-files = { path = "../horizon-server-files" }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 toml = "1.1"
@@ -10,6 +10,9 @@ use std::path::{Path, PathBuf};

 mod normalise;

+pub use horizon_server_files::duration::{
+    DurationUnit, duration_parts, duration_text, now_millis, parse_duration,
+};
 pub use normalise::{Run, Text};

 /// The list built into the game, used when `words_file` is empty.
@@ -474,61 +477,6 @@ pub fn append_log(path: &Path, line: &str) -> std::io::Result<()> {
    writeln!(f, "{line}")
 }

-/// `/tempmute`'s duration in milliseconds: a positive whole number and a unit, `s`, `m`, `h`, `d` or
-/// `w` (`10m`, `2h`, `1d`).
-pub fn parse_duration(text: &str) -> Option<i64> {
-    let unit = match text.chars().last()? {
-        's' => 1_000,
-        'm' => MINUTE,
-        'h' => 60 * MINUTE,
-        'd' => 24 * 60 * MINUTE,
-        'w' => 7 * 24 * 60 * MINUTE,
-        _ => return None,
-    };
-    let count: i64 = text[..text.len() - 1].parse().ok()?;
-    (count > 0).then(|| count.checked_mul(unit)).flatten()
-}
-
-/// The unit used when presenting a moderation duration to a player.
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
-pub enum DurationUnit {
-    Minute,
-    Hour,
-    Day,
-}
-
-/// A duration's rounded count and unit, shared by logs and translated replies.
-pub fn duration_parts(millis: i64) -> (i64, DurationUnit) {
-    let (unit, kind) = if millis <= 60 * MINUTE {
-        (MINUTE, DurationUnit::Minute)
-    } else if millis <= 48 * 60 * MINUTE {
-        (60 * MINUTE, DurationUnit::Hour)
-    } else {
-        (24 * 60 * MINUTE, DurationUnit::Day)
-    };
-    (
-        millis.div_euclid(unit) + i64::from(millis.rem_euclid(unit) > 0),
-        kind,
-    )
-}
-
-/// `millis` for logs, rounded up: minutes up to an hour, hours up to two days, then days.
-pub fn duration_text(millis: i64) -> String {
-    let (count, unit) = duration_parts(millis);
-    let unit = match unit {
-        DurationUnit::Minute => "minute",
-        DurationUnit::Hour => "hour",
-        DurationUnit::Day => "day",
-    };
-    format!("{count} {unit}{}", if count == 1 { "" } else { "s" })
-}
-
-pub fn now_millis() -> i64 {
-    std::time::SystemTime::now()
-        .duration_since(std::time::UNIX_EPOCH)
-        .map_or(0, |d| d.as_millis() as i64)
-}
-
 /// `YYYY-MM-DDTHH:MM:SSZ` for epoch milliseconds.
 pub fn utc(millis: i64) -> String {
    let secs = millis.div_euclid(1000);
@@ -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)]
@@ -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,
+}
@@ -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;
@@ -670,6 +670,39 @@ pub fn with_horizon_icon(
    attributes
 }

+/// The screen a window is on: its size in physical pixels, its refresh rate where the OS gives
+/// it, and its scale. For `horizon-ctl status` and the performance statistics' `system.display`.
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub struct Display {
+    pub width: u32,
+    pub height: u32,
+    pub refresh_hz: Option<u32>,
+    pub scale: f64,
+}
+
+/// The screen `window` is on, else the primary one, else the only one: right after the window
+/// is made, Wayland doesn't say yet which screen it is on.
+pub fn monitor(window: &winit::window::Window) -> Option<winit::monitor::MonitorHandle> {
+    let only = || {
+        let mut all = window.available_monitors();
+        all.next().filter(|_| all.next().is_none())
+    };
+    window
+        .current_monitor()
+        .or_else(|| window.primary_monitor())
+        .or_else(only)
+}
+
+/// [`monitor`]'s size, refresh rate and scale.
+pub fn display(window: &winit::window::Window) -> Option<Display> {
+    monitor(window).map(|m| Display {
+        width: m.size().width,
+        height: m.size().height,
+        refresh_hz: m.refresh_rate_millihertz().map(|r| r.div_ceil(1000)),
+        scale: m.scale_factor(),
+    })
+}
+
 #[cfg(test)]
 mod tests {
    use super::*;
@@ -42,8 +42,6 @@ horizon-chat-filter = { path = "../horizon-chat-filter" }
 horizon-shaders = { path = "../horizon-shaders" }
 # Horizon's own shader packs: the format, the stages and the check (docs/shaders.md).
 horizon-shader-api = { path = "../horizon-shader-api" }
-# Play with Friends: invite codes and their tunnel; the `friends` feature.
-horizon-friends = { path = "../horizon-friends", optional = true }
 # The narrator (GameNarrator): text-to-speech of chat, system messages and screens.
 horizon-narrator = { path = "../horizon-narrator" }
 # Horizon mods: sandboxed WebAssembly components, off unless installed and turned on (docs/mods.md).
@@ -111,16 +109,16 @@ objc2-foundation = { version = "0.3", default-features = false, features = ["std
 wgpu = { version = "30.0.1", default-features = false, features = ["gles"] }

 [features]
-default = ["audio", "controllers", "discord", "friends"]
+default = ["audio", "controllers", "horizon-extras"]
 # 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 still in this crate (docs/forking.md, docs/layers.md): the features below.
+horizon-extras = ["discord"]
 # "Playing Horizon" on the player's Discord profile (`discord_presence`).
 discord = []
-# Play with Friends, joining side (`net.rs`): without it no invite code joins.
-friends = ["dep:horizon-friends"]
 # 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.
@@ -26,7 +26,6 @@ horizon-narrator = { path = "../horizon-narrator" }
 horizon-optifine = { path = "../horizon-optifine" }
 horizon-polytone = { path = "../horizon-polytone" }
 horizon-protocol = { path = "../horizon-protocol" }
-horizon-render-pipeline = { path = "../horizon-render-pipeline" }
 horizon-shader-api = { path = "../horizon-shader-api" }
 horizon-shaders = { path = "../horizon-shaders" }
 horizon-system = { path = "../horizon-system" }
@@ -77,6 +76,10 @@ 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
@@ -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
+    }
+}
@@ -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)?;
@@ -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!(
@@ -362,7 +364,7 @@ fn fixture_frame(hud: &HudBatch) -> Frame<'_> {
        outline: Vec::new(),
        outline_after_terrain: false,
        outline_high_contrast: false,
-        look: Default::default(),
+        pvp: Default::default(),
        debug_lines: &[],
        debug_lines_on_top: &[],
        debug_crosshair: &[],
@@ -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();
@@ -430,7 +432,7 @@ fn fixture_frame(hud: &HudBatch) -> Frame<'_> {
        outline: Vec::new(),
        outline_after_terrain: false,
        outline_high_contrast: false,
-        look: Default::default(),
+        pvp: Default::default(),
        debug_lines: &[],
        debug_lines_on_top: &[],
        debug_crosshair: &[],
@@ -382,8 +382,8 @@ impl RenderAssets {
        };
        // 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 {
@@ -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.
@@ -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!(
@@ -121,8 +121,8 @@ impl CommandBlock {
            condition_met: flag("conditionMet", false),
        }
    }
-    /// `CommandBlockEntity.saveAdditional`. The last output is written as a
-    /// plain string component.
+    /// `CommandBlockEntity.saveAdditional`. The last output is the component
+    /// itself (`ComponentSerialization.CODEC`), styles and click events kept.
    pub fn save(&self) -> Vec<(&'static str, Tag)> {
        let mut out = vec![
            ("Command", Tag::String(self.command.as_str().into())),
@@ -135,7 +135,7 @@ impl CommandBlock {
        if self.track_output
            && let Some(last) = &self.last_output
        {
-            out.push(("LastOutput", Tag::String(last.plain().as_str().into())));
+            out.push(("LastOutput", scoreboard::component_tag(&last.component())));
        }
        out.push((
            "UpdateLastExecution",
@@ -1,27 +1,34 @@
-//! OptiFine custom skies (`horizon_optifine::sky`) as the game draws them: a pack's layers with
-//! their decoded textures, read once with the pack, and each frame's choice of layers, their
-//! brightness and rotation ([`CustomSky::draws`]), which `gfx::custom_sky` draws over the
-//! vanilla sky. A pack without `optifine/sky` gives an empty [`CustomSky`] and the sky stays
-//! vanilla.
+//! Custom sky layers: skyboxes a pack draws over the vanilla sky, in a format vanilla doesn't read
+//! (OptiFine's), which the platform's pack formats fill ([`crate::pack_hooks`]). The layers'
+//! textures are read once with the pack; each frame the game asks for the layers to draw, their
+//! brightness and rotation ([`SkyLayers::draws`]), and `gfx::custom_sky` draws them over the
+//! vanilla sky. A pack without layers keeps the vanilla sky.

 use std::path::Path;
+use std::sync::Arc;

-use glam::{Mat4, Vec3};
-use horizon_optifine::sky::{Blend, Conditions, Skies, SkyLayer, Transition};
+use glam::Mat4;

-/// A layer's texture, RGBA8.
+/// A layer's texture, RGBA8: the skybox's six faces in a 3x2 grid, bottom, top and south in the
+/// top row, west, north and east below (`gfx::custom_sky`'s faces).
 pub struct Image {
    pub width: u32,
    pub height: u32,
    pub rgba: Vec<u8>,
 }

-/// The pack's layers, by world, with one texture per layer (`images[i]` for the `i`th layer
-/// over all worlds, in `worlds` order).
-#[derive(Default)]
-pub struct CustomSky {
-    worlds: Vec<(i32, Vec<SkyLayer>)>,
-    pub images: Vec<Image>,
+/// How a layer mixes with what is drawn below it.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum Blend {
+    Add,
+    Subtract,
+    Multiply,
+    Dodge,
+    Burn,
+    Screen,
+    Replace,
+    Overlay,
+    Alpha,
 }

 /// One layer of a frame: which texture, with which blend, how bright and turned how.
@@ -34,62 +41,44 @@ pub struct Draw {
    pub rotation: Mat4,
 }

+/// The weather of a frame: thunder is a storm's rain, so it is only `Thunder`.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum Weather {
+    Clear,
+    Rain,
+    Thunder,
+}
+
+/// What a frame's layers may depend on.
+#[derive(Clone, Copy, Debug)]
+pub struct Conditions<'a> {
+    /// Ticks of the day, counting the days.
+    pub day_time: i64,
+    pub weather: Weather,
+    /// The biome at the camera, namespaced.
+    pub biome: &'a str,
+    /// The camera's block height.
+    pub y: i32,
+}
+
 /// The eased brightness of each layer, kept by the game between frames.
 #[derive(Default)]
 pub struct State {
-    world: Option<i32>,
-    eased: Vec<Transition>,
+    /// The world the layers were last drawn for.
+    pub world: Option<i32>,
+    /// Each layer's eased visibility, 0 to 1.
+    pub eased: Vec<f32>,
 }

-/// Textures past this many texels in all are left out (a skybox is a few megapixels at most).
-const TEXEL_BUDGET: u64 = 64 << 20;
-
-impl CustomSky {
-    /// The custom skies of the overlay at `root`. A layer whose texture does not decode is
-    /// dropped with a warning.
-    pub fn load(root: &Path) -> Self {
-        let skies = Skies::scan(root);
-        let mut out = Self::default();
-        let mut texels = 0u64;
-        for (world, sky) in skies.worlds {
-            let mut layers = Vec::new();
-            for layer in sky.layers {
-                match crate::hud::decode(&root.join(&layer.source)) {
-                    Ok((width, height, rgba))
-                        if texels + u64::from(width) * u64::from(height) <= TEXEL_BUDGET =>
-                    {
-                        texels += u64::from(width) * u64::from(height);
-                        out.images.push(Image {
-                            width,
-                            height,
-                            rgba,
-                        });
-                        layers.push(layer);
-                    }
-                    Ok(_) => log::warn!("{}: past the custom sky's texture budget", layer.source),
-                    Err(e) => log::warn!("{}: {e:#}", layer.source),
-                }
-            }
-            if !layers.is_empty() {
-                out.worlds.push((world, layers));
-            }
-        }
-        out
-    }
-
-    pub fn is_empty(&self) -> bool {
-        self.worlds.is_empty()
-    }
-
-    /// Whether `world` has layers (`0` the Overworld, `1` the End).
-    pub fn has(&self, world: i32) -> bool {
-        self.worlds.iter().any(|(w, _)| *w == world)
-    }
-
-    /// This frame's layers of `world` into `out` (cleared first), in drawing order: those whose
-    /// conditions hold, eased over their `transition` by `seconds` since the last frame, at the
-    /// brightness of their fade times. `sun_turns` is the sun's angle over 360° (`0` at noon).
-    pub fn draws(
+/// A pack's custom sky layers, by world (`0` the Overworld, `1` the End).
+pub trait SkyLayers: Send + Sync {
+    /// Every layer's texture: [`Draw::image`] indexes it.
+    fn images(&self) -> &[Image];
+    /// Whether `world` has layers.
+    fn has(&self, world: i32) -> bool;
+    /// This frame's layers of `world` into `out` (cleared first), in drawing order, eased by
+    /// `seconds` since the last frame. `sun_turns` is the sun's angle over 360° (`0` at noon).
+    fn draws(
        &self,
        world: i32,
        conditions: &Conditions,
@@ -97,147 +86,30 @@ impl CustomSky {
        seconds: f32,
        state: &mut State,
        out: &mut Vec<Draw>,
-    ) {
+    );
+}
+
+/// No layers: the vanilla sky.
+struct NoLayers;
+
+impl SkyLayers for NoLayers {
+    fn images(&self) -> &[Image] {
+        &[]
+    }
+
+    fn has(&self, _: i32) -> bool {
+        false
+    }
+
+    fn draws(&self, _: i32, _: &Conditions, _: f32, _: f32, s: &mut State, out: &mut Vec<Draw>) {
        out.clear();
-        let mut first = 0;
-        let mut found = None;
-        for (w, layers) in &self.worlds {
-            if *w == world {
-                found = Some(layers);
-                break;
-            }
-            first += layers.len();
-        }
-        let Some(layers) = found else {
-            state.world = None;
-            return;
-        };
-        // A new world (or pack) starts each layer where its conditions put it: no fade in.
-        let snap = state.world != Some(world) || state.eased.len() != layers.len();
-        if snap {
-            state.world = Some(world);
-            state.eased.clear();
-            state.eased.resize(layers.len(), Transition::default());
-        }
-        for (i, (layer, eased)) in layers.iter().zip(&mut state.eased).enumerate() {
-            let target = if layer.shows(conditions) { 1.0 } else { 0.0 };
-            let shown = if snap {
-                eased.value = target;
-                target
-            } else {
-                eased.step(target, seconds, layer.transition)
-            };
-            let brightness = shown * layer.brightness(conditions.day_time);
-            if brightness <= 0.0 {
-                continue;
-            }
-            let turns = layer.turns(conditions.day_time, sun_turns);
-            let rotation = if turns == 0.0 {
-                Mat4::IDENTITY
-            } else {
-                Mat4::from_axis_angle(Vec3::from_array(layer.axis), turns * std::f32::consts::TAU)
-            };
-            out.push(Draw {
-                image: (first + i) as u16,
-                blend: layer.blend,
-                brightness,
-                rotation,
-            });
-        }
+        s.world = None;
    }
 }

-#[cfg(test)]
-mod tests {
-    use super::*;
-    use horizon_optifine::sky::Now;
-
-    fn pack(files: &[(&str, &str)]) -> (std::path::PathBuf, CustomSky) {
-        let root = std::env::temp_dir().join(format!(
-            "horizon-custom-sky-{}-{}",
-            std::process::id(),
-            files.len()
-        ));
-        let _ = std::fs::remove_dir_all(&root);
-        let dir = root.join("assets/minecraft/optifine/sky/world0");
-        std::fs::create_dir_all(&dir).unwrap();
-        let png = {
-            let mut bytes = Vec::new();
-            let mut encoder = png::Encoder::new(&mut bytes, 6, 4);
-            encoder.set_color(png::ColorType::Rgba);
-            encoder.set_depth(png::BitDepth::Eight);
-            let mut writer = encoder.write_header().unwrap();
-            writer
-                .write_image_data(&[255, 0, 0, 255].repeat(24))
-                .unwrap();
-            writer.finish().unwrap();
-            bytes
-        };
-        for (name, text) in files {
-            std::fs::write(dir.join(format!("{name}.properties")), text).unwrap();
-            std::fs::write(dir.join(format!("{name}.png")), &png).unwrap();
-        }
-        let sky = CustomSky::load(&root);
-        (root, sky)
-    }
-
-    fn noon(biome: &str) -> Conditions<'_> {
-        Conditions {
-            day_time: 6000,
-            weather: Now::Clear,
-            biome,
-            y: 64,
-        }
-    }
-
-    #[test]
-    fn layers_ease_in_at_a_biome_border_but_not_on_arrival() {
-        let (root, sky) = pack(&[
-            ("sky1", "biomes=desert\ntransition=2"),
-            ("sky2", "blend=alpha\nrotate=false"),
-        ]);
-        let _ = std::fs::remove_dir_all(root);
-        assert!(sky.has(0) && !sky.has(1));
-        assert_eq!(sky.images[0].width, 6);
-        let (mut state, mut out) = (State::default(), Vec::new());
-        sky.draws(
-            0,
-            &noon("minecraft:desert"),
-            0.0,
-            0.05,
-            &mut state,
-            &mut out,
-        );
-        assert_eq!(
-            out.iter().map(|d| d.brightness).collect::<Vec<_>>(),
-            [1.0, 1.0]
-        );
-        // Out of the desert: the first layer fades over its two seconds.
-        sky.draws(0, &noon("minecraft:plains"), 0.0, 0.5, &mut state, &mut out);
-        assert_eq!(out[0].brightness, 0.75);
-        assert_eq!(out[1].blend, Blend::Alpha);
-        sky.draws(0, &noon("minecraft:plains"), 0.0, 2.0, &mut state, &mut out);
-        assert_eq!(out.len(), 1, "a dark layer is not drawn");
-        assert_eq!(out[0].image, 1);
-        // Into the End, which has no layers, and back: no fade.
-        sky.draws(1, &noon("minecraft:desert"), 0.0, 0.0, &mut state, &mut out);
-        assert!(out.is_empty());
-        sky.draws(0, &noon("minecraft:desert"), 0.0, 0.0, &mut state, &mut out);
-        assert_eq!(out.len(), 2);
-    }
-
-    #[test]
-    fn a_layer_turns_west_like_the_sun() {
-        let (root, sky) = pack(&[("sky1", "")]);
-        let _ = std::fs::remove_dir_all(root);
-        let (mut state, mut out) = (State::default(), Vec::new());
-        // A quarter turn after noon (sunset): the skybox's zenith has gone down to the west.
-        let c = Conditions {
-            day_time: 12000,
-            ..noon("minecraft:plains")
-        };
-        sky.draws(0, &c, 0.25, 0.0, &mut state, &mut out);
-        let up = out[0].rotation.transform_vector3(Vec3::Y);
-        assert!((up - Vec3::NEG_X).length() < 1e-5, "{up}");
-    }
+/// The custom sky layers of the overlay at `root`, from the installed pack formats.
+pub fn load(root: &Path) -> Arc<dyn SkyLayers> {
+    crate::pack_hooks::formats()
+        .custom_sky(root)
+        .unwrap_or_else(|| Arc::new(NoLayers))
 }
@@ -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 {
@@ -1,5 +1,6 @@
 //! The Horizon Extras page, on the settings shell (`settings_shell`): which rows it has and what
-//! pressing them does. Each one's value and what it does stay in `extras::Item`.
+//! pressing them does. Each one's value and what it does stay in `extras::Item`; the sections crates
+//! add (`horizon_hooks::pages::Place::Extras`) keep theirs.
 use crate::{
    extras::{self, Item},
    lang,
@@ -7,6 +8,7 @@ use crate::{
    settings::Settings,
    settings_shell::{self as shell, Binding, Group, Output, Row, Screen, Sheet, Value},
 };
+use horizon_hooks::pages::{self as added, Act, Label};

 const TITLE: &str = "horizon.pages.extras";
 const ABOUT: &str = "horizon.pages.extras.tooltip";
@@ -31,6 +33,125 @@ pub(crate) enum ExtraRow {
    /// It isn't installed: where to get it. A note, not a button: Options > Mods already has the
    /// one way into the Mods page (`every_setting_and_page_is_reached_from_one_place`).
    ZoomInstall,
+    /// Row `.1` of the section registered page `.0` adds (`Place::Extras`).
+    Added(usize, usize),
+}
+
+#[cfg(test)]
+thread_local! {
+    /// A test's own pages, instead of the game's registered ones: each test runs on its thread.
+    static TEST_PAGES: std::cell::Cell<Option<&'static [&'static dyn added::Page]>> =
+        const { std::cell::Cell::new(None) };
+}
+
+/// The pages crates registered, all places.
+fn pages() -> &'static [&'static dyn added::Page] {
+    #[cfg(test)]
+    if let Some(pages) = TEST_PAGES.get() {
+        return pages;
+    }
+    added::engine::all()
+}
+
+/// The sections of this page, by their index among the registered pages.
+fn sections() -> impl Iterator<Item = (usize, &'static dyn added::Page)> {
+    let pages = pages().iter().copied().enumerate();
+    pages.filter(|(_, page)| page.place() == added::Place::Extras)
+}
+
+fn label_text(label: Label) -> String {
+    match label {
+        Label::Key(key) => lang::get(key),
+        Label::Value(text) => text,
+    }
+}
+
+/// The page's group named `name`, made at the end if it has none.
+fn group_named<'a>(
+    groups: &'a mut Vec<Group<ExtraRow>>,
+    name: &'static str,
+) -> &'a mut Group<ExtraRow> {
+    let at = groups.iter().position(|group| group.name == name);
+    let at = at.unwrap_or_else(|| {
+        groups.push(Group {
+            name,
+            rows: Vec::new(),
+        });
+        groups.len() - 1
+    });
+    &mut groups[at]
+}
+
+/// The sections' rows, in the groups their titles and headings name.
+fn add_sections(groups: &mut Vec<Group<ExtraRow>>) {
+    for (page, section) in sections() {
+        let mut rows = Vec::new();
+        section.rows(&mut rows);
+        let mut name = section.title();
+        for (r, row) in rows.into_iter().enumerate() {
+            let id = ExtraRow::Added(page, r);
+            let row = match row {
+                added::Row::Heading(key) => {
+                    name = key;
+                    continue;
+                }
+                added::Row::Note(text) => Row::new(id, text, Value::Note).live(false),
+                added::Row::Toggle { label, on } => {
+                    Row::new(id, lang::get(label), Value::Switch(on))
+                }
+                added::Row::Cycle { label, value } => {
+                    Row::new(id, lang::get(label), Value::Choice(label_text(value)))
+                }
+                added::Row::Slider { label, value, text } => {
+                    let position = value.clamp(0.0, 1.0);
+                    let text = label_text(text);
+                    let value = Value::Slider {
+                        position,
+                        steps: None,
+                        text,
+                    };
+                    Row::new(id, lang::get(label), value)
+                }
+                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))
+                }
+                // A row kind newer than this engine.
+                _ => continue,
+            };
+            let row = match section.tooltip(r) {
+                Some(about) => row.about(label_text(about)),
+                None => row,
+            };
+            group_named(groups, name).rows.push(row);
+        }
+    }
+}
+
+/// Row `r` of registered page `page` was acted on: the options screen saves when it closes.
+fn act(page: usize, r: usize, act: Act) -> Vec<Output> {
+    let Some(section) = pages().get(page) else {
+        return Vec::new();
+    };
+    section.act(r, act);
+    vec![Output::Event(Event::Changed)]
+}
+
+/// Whether row `r` of registered page `page` steps (a switch or a cycle).
+fn steps(page: usize, r: usize) -> bool {
+    let mut rows = Vec::new();
+    if let Some(section) = pages().get(page) {
+        section.rows(&mut rows);
+    }
+    matches!(
+        rows.get(r),
+        Some(added::Row::Toggle { .. } | added::Row::Cycle { .. })
+    )
 }

 fn item_row(item: Item, s: &Settings) -> Row<ExtraRow> {
@@ -85,9 +206,14 @@ impl Screen for ExtrasScreen {
    fn note_lines(&self) -> usize {
        NOTE_LINES
    }
-    /// The rows read the extras, the mods and whether cosmetics are offered.
+    /// The rows read the extras, the mods, whether cosmetics are offered and the sections' rows.
    fn stamp(&self, s: &Settings) -> u64 {
-        shell::stamp_of(&(&s.extras, &s.mods, horizon_cosmetics::enabled()))
+        let mut added = Vec::new();
+        for (_, section) in sections() {
+            section.rows(&mut added);
+        }
+        let cosmetics = horizon_cosmetics::enabled();
+        shell::stamp_of(&(&s.extras, &s.mods, cosmetics, added))
    }
    fn sheets(&self, s: &Settings) -> Vec<Sheet<(), ExtraRow>> {
        let mut groups = vec![Group {
@@ -107,6 +233,7 @@ impl Screen for ExtrasScreen {
                }
            }
        }
+        add_sections(&mut groups);
        vec![Sheet::new((), lang::get(TITLE), lang::get(ABOUT), groups)]
    }
    fn press(&mut self, s: &mut Settings, row: ExtraRow, back: bool) -> Vec<Output> {
@@ -125,16 +252,29 @@ impl Screen for ExtrasScreen {
                Output::Event(Event::NativeSettings(i)),
            ],
            ExtraRow::ZoomInstall => Vec::new(),
+            ExtraRow::Added(page, r) => {
+                act(page, r, if back { Act::PressBack } else { Act::Press })
+            }
+        }
+    }
+    fn slide(&mut self, _s: &mut Settings, row: ExtraRow, position: f32) {
+        if let ExtraRow::Added(page, r) = row {
+            act(page, r, Act::Slide(position));
        }
    }
    /// With the wheel extra on, the wheel over an item changes it, without a click; the mod's rows
    /// let the list scroll.
    fn wheel_step(&mut self, s: &mut Settings, row: ExtraRow, back: bool) -> Option<Vec<Output>> {
-        let ExtraRow::Item(item) = row else {
-            return None;
-        };
-        item.cycle(&mut s.extras, back);
-        Some(vec![Output::Event(Event::Changed)])
+        match row {
+            ExtraRow::Item(item) => {
+                item.cycle(&mut s.extras, back);
+                Some(vec![Output::Event(Event::Changed)])
+            }
+            ExtraRow::Added(page, r) if steps(page, r) => {
+                Some(act(page, r, if back { Act::PressBack } else { Act::Press }))
+            }
+            _ => None,
+        }
    }
 }

@@ -292,4 +432,146 @@ mod tests {
        shell.key(&mut s, K::ArrowDown, None, false, size);
        assert_eq!(shell.focused_row(), Some(first));
    }
+
+    /// A section with a switch in the page's Multiplayer group, then a heading of its own with a
+    /// number that steps either way, a note and a volume.
+    struct Section {
+        on: std::sync::Mutex<bool>,
+        step: std::sync::Mutex<i32>,
+        volume: std::sync::Mutex<f32>,
+    }
+    impl added::Page for Section {
+        fn id(&self) -> &'static str {
+            "test.section"
+        }
+        fn title(&self) -> &'static str {
+            "horizon.extras.header.multiplayer"
+        }
+        fn place(&self) -> added::Place {
+            added::Place::Extras
+        }
+        fn rows(&self, rows: &mut Vec<added::Row>) {
+            rows.push(added::Row::Toggle {
+                label: "test.section.switch",
+                on: *self.on.lock().unwrap(),
+            });
+            rows.push(added::Row::Heading("test.section.heading"));
+            rows.push(added::Row::Cycle {
+                label: "test.section.step",
+                value: Label::Value(self.step.lock().unwrap().to_string()),
+            });
+            rows.push(added::Row::Note("a note".into()));
+            rows.push(added::Row::Slider {
+                label: "test.section.volume",
+                value: *self.volume.lock().unwrap(),
+                text: Label::Value(String::new()),
+            });
+        }
+        fn act(&self, row: usize, act: Act) {
+            match (row, act) {
+                (0, Act::Press | Act::PressBack) => {
+                    let mut on = self.on.lock().unwrap();
+                    *on = !*on;
+                }
+                (2, Act::Press) => *self.step.lock().unwrap() += 1,
+                (2, Act::PressBack) => *self.step.lock().unwrap() -= 1,
+                (4, Act::Slide(v)) => *self.volume.lock().unwrap() = v,
+                _ => {}
+            }
+        }
+    }
+
+    /// A page for Horizon Settings: never on Extras.
+    struct Elsewhere;
+    impl added::Page for Elsewhere {
+        fn id(&self) -> &'static str {
+            "test.elsewhere"
+        }
+        fn title(&self) -> &'static str {
+            "test.elsewhere"
+        }
+        fn place(&self) -> added::Place {
+            added::Place::HorizonSettings
+        }
+        fn rows(&self, rows: &mut Vec<added::Row>) {
+            rows.push(added::Row::button("test.elsewhere.button"));
+        }
+        fn act(&self, _: usize, _: Act) {}
+    }
+
+    fn with_section() -> &'static Section {
+        let section: &'static Section = Box::leak(Box::new(Section {
+            on: false.into(),
+            step: 0.into(),
+            volume: 0.5.into(),
+        }));
+        let pages: &'static [&'static dyn added::Page] = Box::leak(Box::new([
+            &Elsewhere as &dyn added::Page,
+            section as &dyn added::Page,
+        ]));
+        TEST_PAGES.set(Some(pages));
+        section
+    }
+
+    /// The section's first row joins the page's own Multiplayer group, after its rows; its heading
+    /// starts a group after the page's; a page for elsewhere adds nothing.
+    #[test]
+    fn a_section_joins_the_group_its_title_names_and_heads_its_own() {
+        with_section();
+        let s = Settings::default();
+        let sheets = ExtrasScreen.sheets(&s);
+        let groups = &sheets[0].groups;
+        let ids = |name: &str| -> Vec<ExtraRow> {
+            let group = groups.iter().find(|g| g.name == name).unwrap();
+            group.rows.iter().map(|r| r.id).collect()
+        };
+        let multiplayer = ids("horizon.extras.header.multiplayer");
+        assert_eq!(multiplayer.last(), Some(&ExtraRow::Added(1, 0)));
+        assert_eq!(groups.last().unwrap().name, "test.section.heading");
+        let own = [
+            ExtraRow::Added(1, 2),
+            ExtraRow::Added(1, 3),
+            ExtraRow::Added(1, 4),
+        ];
+        assert_eq!(ids("test.section.heading"), own);
+        let all = rows_of(&s);
+        assert!(!all.iter().any(|r| matches!(r.id, ExtraRow::Added(0, _))));
+    }
+
+    /// A click flips the switch, a Shift click steps the number back, the wheel steps it, and the
+    /// note takes no click; the rows show what the section holds after each.
+    #[test]
+    fn a_sections_rows_act_on_it() {
+        let section = with_section();
+        let mut s = Settings::default();
+        let mut shell = Shell::<ExtrasScreen>::default();
+        let switch = ExtraRow::Added(1, 0);
+        let at = shell.point_at(&s, SIZE, switch);
+        assert!(
+            !shell
+                .click(&mut s, at, SIZE, false, false, false)
+                .is_empty()
+        );
+        assert!(*section.on.lock().unwrap());
+        let value = |s: &Settings, id| rows_of(s).into_iter().find(|r| r.id == id).unwrap().value;
+        assert_eq!(value(&s, switch), Value::Switch(true));
+        let step = ExtraRow::Added(1, 2);
+        let mut screen = ExtrasScreen;
+        screen.press(&mut s, step, true);
+        assert_eq!(value(&s, step), Value::Choice("-1".into()));
+        assert!(screen.wheel_step(&mut s, step, false).is_some());
+        assert_eq!(*section.step.lock().unwrap(), 0);
+        assert_eq!(
+            screen.wheel_step(&mut s, ExtraRow::Added(1, 3), false),
+            None
+        );
+        let note = shell.point_at(&s, SIZE, ExtraRow::Added(1, 3));
+        assert!(
+            shell
+                .click(&mut s, note, SIZE, false, false, false)
+                .is_empty()
+        );
+        screen.slide(&mut s, ExtraRow::Added(1, 4), 0.25);
+        assert_eq!(*section.volume.lock().unwrap(), 0.25);
+    }
 }
@@ -231,8 +231,10 @@ pub struct FogInputs<'a> {
    /// `GameRenderer.nightVisionScale` while Night Vision is on without
    /// Darkness, else 0 (`FogRenderer.computeFogColor`'s brightenFactor).
    pub night_vision: f32,
-    /// The packs' Polytone `environment` fog settings.
-    pub environment: horizon_polytone::colors::Environment,
+    /// 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]
@@ -581,7 +602,7 @@ mod tests {
        let tables = FogTables {
            water_fog_end: vec![1.0],
        };
-        let environment = horizon_polytone::colors::Environment {
+        let environment = crate::pack_palette::Environment {
            powder_snow_fog: Some(0xFF0000),
            blindness_fog_distance: 40.0,
            water_fog_brightening: 0.0,
@@ -611,9 +632,41 @@ 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: horizon_polytone::colors::Environment,
+        environment: crate::pack_palette::Environment,
    ) -> FogInputs<'a> {
        FogInputs {
            environment,
@@ -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;
@@ -236,9 +237,11 @@ 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};
+mod off_page;
 pub mod submit;
 mod sunrise_fan;
 mod timing;
@@ -250,6 +253,7 @@ mod wgsl_prefix;
 mod world_post;
 pub mod world_primitives;
 mod world_warp;
+use off_page::move_off_page;

 /// A section's instance: its camera-relative origin and, in `w`, the step of
 /// its fixed-point UVs (`terrain.wgsl`'s `terrain_uv`).
@@ -726,62 +730,6 @@ impl Part {
        }
    }
 }
-/// `Renderer::compact_arena`'s and `shrink_translucent`'s moves: what the meshes
-/// hold on `page` of `arena` (`part`) goes to its other pages in video memory,
-/// until the next range would pass `budget` bytes (it keeps what is left; the
-/// first range moves whatever its size, so none keeps the page closed), the
-/// copies into `encoder`, the ranges' flat draw ids (`flat`) and, in the
-/// section arena, GPU culling's records (`records`) along. False when the other
-/// pages have no room left.
-fn move_off_page<'a>(
-    arena: &mut arena::Arena,
-    encoder: &mut wgpu::CommandEncoder,
-    mut flat: Option<(&mut flat::Flat, &wgpu::Device, &mut upload::Uploads)>,
-    mut records: Option<&mut gpu_culling::Records>,
-    meshes: impl Iterator<Item = &'a mut SectionGpu>,
-    page: u32,
-    part: Part,
-    budget: &mut u64,
-) -> bool {
-    debug_assert!(
-        records.is_none() || matches!(part, Part::Section { .. }),
-        "records follow the section arena's ranges"
-    );
-    let mut moved = false;
-    for s in meshes {
-        // Nothing of a mesh here: split, one without solid quads (its (0, 0) is no
-        // range of page 0); in the other arenas, one without translucent quads.
-        let Some((_, start, vertices)) = part.of(s).filter(|r| r.0 == page) else {
-            continue;
-        };
-        let bytes = vertices * arena.stride();
-        if moved && bytes > *budget {
-            break;
-        }
-        let Some(to) = arena.alloc_moved(vertices) else {
-            return false;
-        };
-        arena.copy(encoder, (page, start), to, vertices);
-        arena.release(page, start, vertices);
-        if let (Some((flat, device, uploads)), Some(id)) = (&mut flat, s.flat_id) {
-            let key = match part {
-                Part::Translucent => to.0 + flat::TRANSLUCENT_KEYS,
-                _ => to.0,
-            };
-            flat.place(device, encoder, uploads, id, key, to.1, vertices);
-        }
-        part.set(s, to);
-        // Its solid quads start the range in either layout.
-        if let (Part::Section { .. }, Some(records), Some(id)) =
-            (part, records.as_deref_mut(), s.gpu_id)
-        {
-            records.relocate(id, to.0, u64::from(s.solid_base()));
-        }
-        *budget = budget.saturating_sub(bytes);
-        moved = true;
-    }
-    true
-}
 /// Starts moving a page of a large arena far larger than its ranges in use
 /// (`Arena::oversized`) into a new page of the size they get (`Arena::open_page`),
 /// for `Renderer::shrink_translucent`: the page closes and `move_off_page` empties
@@ -1001,8 +949,8 @@ pub struct Frame<'a> {
    pub outline_after_terrain: bool,
    /// `BlockOutlineRenderState.highContrast`: a thick black outline under a bright one.
    pub outline_high_contrast: bool,
-    /// The outline, hurt overlay and glint colours a crate above set (`horizon_hooks::look`).
-    pub look: horizon_hooks::look::Frame,
+    /// The PvP & HUD page's outline and hit colour (`pvp::Frame`; default: vanilla's).
+    pub pvp: crate::pvp::Frame,
    /// `lines` with a colour and pixel width (`gizmos::camera_relative`):
    /// the fishing line and debug gizmos, depth tested, then gizmos drawn
    /// over everything.
@@ -1138,6 +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
@@ -1329,7 +1280,7 @@ pub struct Renderer {
    celestial_buffer: wgpu::Buffer,
    end_sky: end_sky::EndSky,
    stars: stars::Stars,
-    /// OptiFine custom sky layers (`crate::custom_sky`), and the frame's from the game.
+    /// Custom sky layers (`crate::custom_sky`), and the frame's from the game.
    custom_sky: custom_sky::CustomSky,
    custom_sky_draws: Vec<crate::custom_sky::Draw>,
    /// The glowing entities' outline (`LevelRenderer.entityOutlineTarget`).
@@ -1632,6 +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,
@@ -5131,6 +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,
@@ -5402,6 +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,
@@ -5517,11 +5474,11 @@ impl Renderer {
            ))
        });
    }
-    /// The pack's OptiFine custom sky layer textures (`crate::custom_sky::CustomSky::load`).
-    pub fn set_custom_sky(&mut self, pack: &crate::custom_sky::CustomSky) {
+    /// The pack's custom sky layer textures (`crate::custom_sky::load`).
+    pub fn set_custom_sky(&mut self, pack: &dyn crate::custom_sky::SkyLayers) {
        self.custom_sky.set_pack(&self.device, &self.queue, pack);
    }
-    /// The custom sky layers the next frame draws (`CustomSky::draws`): the game refills it each
+    /// The custom sky layers the next frame draws (`SkyLayers::draws`): the game refills it each
    /// frame, empty when the world's sky has none.
    pub fn custom_sky_draws(&mut self) -> &mut Vec<crate::custom_sky::Draw> {
        &mut self.custom_sky_draws
@@ -7095,8 +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`).
@@ -8029,6 +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()));
@@ -8373,9 +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;
        }
@@ -8506,9 +8465,9 @@ impl Renderer {
            colored_count: [
                frame.colored_lights.len().min(crate::dynamic_light::MAX) as u32,
                // PvP & HUD's hit colour: entity.wgsl's hurt texel, 0 for vanilla's.
-                frame.look.hurt_texel,
+                frame.pvp.hurt_texel,
                // PvP & HUD's glint colour: entity.wgsl's `tinted_glint`, 0 for vanilla's.
-                frame.look.glint,
+                frame.pvp.glint,
                0,
            ],
            emissive_layers: {
@@ -9495,7 +9454,7 @@ impl Renderer {
                }
            };
            // A custom outline (PvP & HUD) takes the bright stroke's colour, scales both widths.
-            let (custom, scale) = frame.look.outline.map_or((None, 1.0), |o| (Some(o.0), o.1));
+            let (custom, scale) = frame.pvp.outline.map_or((None, 1.0), |(c, s)| (Some(c), s));
            if frame.outline_high_contrast {
                stroke(0xff00_0000, 7.0 * scale, lines);
                stroke(custom.unwrap_or(0xff57_ffe1), width * scale, lines);
@@ -10116,7 +10075,11 @@ impl Renderer {
        let pack_reads_world = pack_post || native_post;
        laps.lap("r_uploads");
        // Phase 2 of occlusion culling draws over the depth, and a shader pack or TAA reads it.
+        // Post effects (a resource pack's chains, `use_depth_buffer`) read the world's depth
+        // after the world pass, as `GameRenderer.render` hands them the main target's.
+        let post_reads_depth = !frame.title && !frame.post_effects.effects.is_empty();
        let keep_depth = pack_reads_world
+            || post_reads_depth
            || (taa && self.world_post.taa)
            || oit_on
            || native_render::render_needs().world_depth
@@ -12094,24 +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).
@@ -12714,96 +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 {
@@ -13714,6 +13597,7 @@ mod tests {
            Some(Reported {
                paper_white: 240,
                peak: 998,
+                peak_guessed: true,
            })
        );
        assert_eq!(
@@ -13721,6 +13605,7 @@ mod tests {
            Some(Reported {
                paper_white: 480,
                peak: 480,
+                peak_guessed: true,
            })
        );
        // White above the calibrated peak (a Samsung QD-OLED's 380, the slider at 456).
@@ -13729,6 +13614,7 @@ mod tests {
            Some(Reported {
                paper_white: 456,
                peak: 456,
+                peak_guessed: true,
            })
        );
        assert_eq!(os_reported(&info(Some(1000.0), None)), None);
@@ -15419,11 +15305,9 @@ fn log_os_reported(reported: Option<crate::graphics::Reported>) {
        None => "Horizon renderer: the system doesn't report the display's luminance".into(),
    });
 }
-/// What the OS reports in absolute nits (Windows: DXGI's `MaxLuminance` and the SDR
-/// white level the brightness slider sets), which is HDR output's scale there: SDR
-/// white is Paper White, the display's peak is Peak Brightness. Both are kept within
-/// the settings' ranges. The OS's figures often come from the display's EDID and may
-/// run optimistic; the player's own value always wins.
+/// What the OS reports in absolute nits, HDR output's scale (Windows: DXGI's SDR white level,
+/// the brightness slider's, as Paper White, and its `MaxLuminance`, mostly the display's EDID
+/// guess, as Peak Brightness), kept within the settings' ranges. The player's values win.
 fn os_reported(info: &wgpu::DisplayHdrInfo) -> Option<crate::graphics::Reported> {
    let luminance = info.luminance?;
    let usable = |n: f32| n.is_finite() && n > 0.0;
@@ -15435,6 +15319,7 @@ fn os_reported(info: &wgpu::DisplayHdrInfo) -> Option<crate::graphics::Reported>
        // Windows' SDR brightness slider can set white above the reported peak (480 against
        // a calibrated 380): the highlights then stay at white instead of dropping below it.
        peak: (peak.round() as u32).clamp(200, 10_000).max(paper_white),
+        peak_guessed: true,
    })
 }

@@ -15470,6 +15355,7 @@ fn reported(l: horizon_hdr::wayland::Luminances) -> crate::graphics::Reported {
    crate::graphics::Reported {
        paper_white: 203,
        peak: peak.clamp(200, 10_000),
+        peak_guessed: false,
    }
 }

@@ -15718,11 +15604,11 @@ mod shadow_caster_tests {
    #[test]
    fn the_shadow_pass_draws_terrain_outside_the_pack_s_planes() {
        let kept = |near: Option<f32>, far: Option<f32>, y: f64, min: [f32; 3], depth: bool| {
-            let shadow = horizon_render_pipeline::Shadow {
+            let shadow = horizon_shaders::Shadow {
                distance: 128.0,
                near,
                far,
-                ..horizon_render_pipeline::Shadow::default()
+                ..horizon_shaders::Shadow::default()
            };
            let camera = DVec3::new(13.5, y + 1.62, -13.5);
            let view = pack_post::ShadowView {
@@ -524,7 +524,7 @@ impl Scene {
            outline: Vec::new(),
            outline_after_terrain: false,
            outline_high_contrast: false,
-            look: Default::default(),
+            pvp: Default::default(),
            debug_lines: &[],
            debug_lines_on_top: &[],
            debug_crosshair: &[],
@@ -1,12 +1,11 @@
-//! OptiFine custom sky layers on the GPU: one texture per layer, kept with the renderer (its pack),
+//! Custom sky layers (`crate::custom_sky`) on the GPU: one texture per layer, kept with the renderer (its pack),
 //! a static skybox mesh of the 3x2 grid's six faces, and one pipeline per blend mode. A frame
 //! uploads one small uniform per drawn layer ([`crate::custom_sky::Draw`]) and draws 36 vertices
 //! each, after the vanilla sky's disc and sunrise and before the sun, moon and stars.
 use glam::Mat4;
-use horizon_optifine::sky::{Blend, Face};
 use wgpu::util::DeviceExt;

-use crate::custom_sky::{CustomSky as Pack, Draw};
+use crate::custom_sky::{Blend, Draw, SkyLayers};

 /// The blend modes in the shader's `mode` order (custom_sky.wgsl).
 const MODES: [Blend; 9] = [
@@ -85,6 +84,76 @@ fn blend(mode: Blend) -> wgpu::BlendComponent {
    }
 }

+/// A face of the skybox, as the 3x2 grid of its texture holds them: `Bottom`, `Top`, `South` in
+/// the top row, `West`, `North`, `East` below.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+enum Face {
+    Bottom,
+    Top,
+    South,
+    West,
+    North,
+    East,
+}
+
+impl Face {
+    const ALL: [Self; 6] = [
+        Self::Bottom,
+        Self::Top,
+        Self::South,
+        Self::West,
+        Self::North,
+        Self::East,
+    ];
+
+    /// The face's cell of the texture, `[u0, v0, u1, v1]` in 0..1.
+    fn cell(self) -> [f32; 4] {
+        let (col, row) = match self {
+            Self::Bottom => (0, 0),
+            Self::Top => (1, 0),
+            Self::South => (2, 0),
+            Self::West => (0, 1),
+            Self::North => (1, 1),
+            Self::East => (2, 1),
+        };
+        let (u, v) = (col as f32 / 3.0, row as f32 / 2.0);
+        [u, v, u + 1.0 / 3.0, v + 0.5]
+    }
+
+    /// The face's corners (on the unit cube around the camera; x east, y up, z south) in the
+    /// order of its cell's `(u0, v0)`, `(u1, v0)`, `(u1, v1)`, `(u0, v1)`. The side faces are
+    /// seen from inside with up at the top of their cell; the top face has north at the bottom of
+    /// its cell, the bottom face north at the top (the template's `N` marks).
+    fn corners(self) -> [[f32; 3]; 4] {
+        match self {
+            // Seen looking north: west on the left.
+            Self::North => [
+                [-1., 1., -1.],
+                [1., 1., -1.],
+                [1., -1., -1.],
+                [-1., -1., -1.],
+            ],
+            Self::South => [[1., 1., 1.], [-1., 1., 1.], [-1., -1., 1.], [1., -1., 1.]],
+            Self::East => [[1., 1., -1.], [1., 1., 1.], [1., -1., 1.], [1., -1., -1.]],
+            Self::West => [
+                [-1., 1., 1.],
+                [-1., 1., -1.],
+                [-1., -1., -1.],
+                [-1., -1., 1.],
+            ],
+            // Looking up with north toward the cell's bottom edge: east on the right.
+            Self::Top => [[-1., 1., 1.], [1., 1., 1.], [1., 1., -1.], [-1., 1., -1.]],
+            // Looking down with north toward the cell's top edge: east on the right.
+            Self::Bottom => [
+                [-1., -1., -1.],
+                [1., -1., -1.],
+                [1., -1., 1.],
+                [-1., -1., 1.],
+            ],
+        }
+    }
+}
+
 /// The skybox's 36 vertices: two triangles per face, each corner with its cell's UV.
 fn mesh() -> Vec<Vertex> {
    let mut out = Vec::with_capacity(36);
@@ -256,10 +325,15 @@ impl CustomSky {
    }

    /// The pack's layer textures, replacing any before.
-    pub(super) fn set_pack(&mut self, device: &wgpu::Device, queue: &wgpu::Queue, pack: &Pack) {
+    pub(super) fn set_pack(
+        &mut self,
+        device: &wgpu::Device,
+        queue: &wgpu::Queue,
+        pack: &dyn SkyLayers,
+    ) {
        let limit = device.limits().max_texture_dimension_2d;
        self.groups = pack
-            .images
+            .images()
            .iter()
            .map(|image| {
                // Too large for this GPU: a 1x1 transparent texel, so the layer draws nothing.
@@ -413,6 +487,38 @@ impl CustomSky {
 mod tests {
    use super::*;

+    #[test]
+    fn the_grid_holds_each_face_once_and_faces_point_out() {
+        let mut cells: Vec<_> = Face::ALL
+            .iter()
+            .map(|f| f.cell().map(|x| (x * 6.0) as i32))
+            .collect();
+        cells.dedup();
+        assert_eq!(cells.len(), 6);
+        assert_eq!(Face::East.cell(), [2.0 / 3.0, 0.5, 1.0, 1.0]);
+        for face in Face::ALL {
+            let c = face.corners();
+            let sub = |a: [f32; 3], b: [f32; 3]| [a[0] - b[0], a[1] - b[1], a[2] - b[2]];
+            let (a, b) = (sub(c[1], c[0]), sub(c[3], c[0]));
+            let n = [
+                a[1] * b[2] - a[2] * b[1],
+                a[2] * b[0] - a[0] * b[2],
+                a[0] * b[1] - a[1] * b[0],
+            ];
+            let centre: [f32; 3] =
+                std::array::from_fn(|i| c.iter().map(|p| p[i]).sum::<f32>() / 4.0);
+            // Seen from inside, u runs right and v down, so u x v points away from the camera.
+            let dot: f32 = (0..3).map(|i| n[i] * centre[i]).sum();
+            assert!(dot > 0.0, "{face:?} is mirrored");
+        }
+        // The top cell's bottom edge (v1) is north: its corners 2 and 3 have z = -1.
+        assert_eq!(Face::Top.corners()[2][2], -1.0);
+        assert_eq!(Face::Top.corners()[3][2], -1.0);
+        // The bottom cell's top edge (v0) is north.
+        assert_eq!(Face::Bottom.corners()[0][2], -1.0);
+        assert_eq!(Face::Bottom.corners()[1][2], -1.0);
+    }
+
    /// What a blend leaves a sky texel of `dst` with when the shader outputs `src`
    /// (custom_sky.wgsl) for a layer texel `t` at brightness `b`, per channel.
    fn mix(mode: Blend, dst: f32, t: f32, a: f32, b: f32) -> f32 {
@@ -6,7 +6,7 @@ struct Layer {
    // Projection * view (camera-relative) * the layer's rotation.
    clip_from_sky: mat4x4<f32>,
    brightness: f32,
-    // horizon_optifine::sky::Blend, in gfx/custom_sky.rs's MODES order.
+    // crate::custom_sky::Blend, in gfx/custom_sky.rs's MODES order.
    mode: u32,
    pad: vec2<u32>,
    hdr_settings: vec4<f32>,
@@ -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.
@@ -338,7 +338,7 @@ pub struct NativeFrame {
    reflection_sampler: wgpu::Sampler,
    /// The shadow map the stages read, and the camera that draws it when the pack asks for one.
    pub shadow_map: super::native_shadow::ShadowMap,
-    shadow_camera: Option<horizon_render_pipeline::Shadow>,
+    shadow_camera: Option<horizon_shaders::Shadow>,
    /// Whether the pack's material reads `reflection` (`NativePack::new`): else no mirror
    /// is drawn and `has_reflection` stays 0.
    pub reflects: bool,
@@ -1497,7 +1497,7 @@ pub fn frame_inputs(
    size: [u32; 2],
    seconds: f32,
    index: u32,
-    shadow: Option<&horizon_render_pipeline::Shadow>,
+    shadow: Option<&horizon_shaders::Shadow>,
 ) -> FrameInputs {
    let aspect = size[0] as f32 / size[1].max(1) as f32;
    let view = crate::camera::view_matrix(frame.yaw, frame.pitch);
@@ -6,8 +6,8 @@
 //! draw lists (`ShadowView`) serve both; the map's texels are distorted toward the camera as the
 //! prelude's `shadow_position` undoes.

-use horizon_render_pipeline::Shadow;
 use horizon_shader_api::{Api, Frame as FrameInputs, manifest::Shadow as Settings, stages::GROUP};
+use horizon_shaders::Shadow;

 use super::native_material::TerrainShape;
 use super::wgsl_prefix::{TERRAIN, prefixed, section};
@@ -0,0 +1,59 @@
+//! `move_off_page`, moved out of `gfx.rs` unchanged.
+use super::*;
+
+/// `Renderer::compact_arena`'s and `shrink_translucent`'s moves: what the meshes
+/// hold on `page` of `arena` (`part`) goes to its other pages in video memory,
+/// until the next range would pass `budget` bytes (it keeps what is left; the
+/// first range moves whatever its size, so none keeps the page closed), the
+/// copies into `encoder`, the ranges' flat draw ids (`flat`) and, in the
+/// section arena, GPU culling's records (`records`) along. False when the other
+/// pages have no room left.
+pub(super) fn move_off_page<'a>(
+    arena: &mut arena::Arena,
+    encoder: &mut wgpu::CommandEncoder,
+    mut flat: Option<(&mut flat::Flat, &wgpu::Device, &mut upload::Uploads)>,
+    mut records: Option<&mut gpu_culling::Records>,
+    meshes: impl Iterator<Item = &'a mut SectionGpu>,
+    page: u32,
+    part: Part,
+    budget: &mut u64,
+) -> bool {
+    debug_assert!(
+        records.is_none() || matches!(part, Part::Section { .. }),
+        "records follow the section arena's ranges"
+    );
+    let mut moved = false;
+    for s in meshes {
+        // Nothing of a mesh here: split, one without solid quads (its (0, 0) is no
+        // range of page 0); in the other arenas, one without translucent quads.
+        let Some((_, start, vertices)) = part.of(s).filter(|r| r.0 == page) else {
+            continue;
+        };
+        let bytes = vertices * arena.stride();
+        if moved && bytes > *budget {
+            break;
+        }
+        let Some(to) = arena.alloc_moved(vertices) else {
+            return false;
+        };
+        arena.copy(encoder, (page, start), to, vertices);
+        arena.release(page, start, vertices);
+        if let (Some((flat, device, uploads)), Some(id)) = (&mut flat, s.flat_id) {
+            let key = match part {
+                Part::Translucent => to.0 + flat::TRANSLUCENT_KEYS,
+                _ => to.0,
+            };
+            flat.place(device, encoder, uploads, id, key, to.1, vertices);
+        }
+        part.set(s, to);
+        // Its solid quads start the range in either layout.
+        if let (Part::Section { .. }, Some(records), Some(id)) =
+            (part, records.as_deref_mut(), s.gpu_id)
+        {
+            records.relocate(id, to.0, u64::from(s.solid_base()));
+        }
+        *budget = budget.saturating_sub(bytes);
+        moved = true;
+    }
+    true
+}
@@ -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,
    }
 }

@@ -300,6 +319,7 @@ pub(crate) mod tests {
                luminance: Some(Reported {
                    paper_white: 400,
                    peak: 1000,
+                    peak_guessed: false,
                }),
                hdr: system,
            },
@@ -650,6 +670,7 @@ pub(crate) mod tests {
        window_reading.luminance = Some(Reported {
            paper_white: 300,
            peak: 800,
+            peak_guessed: false,
        });
        assert_eq!(window_output(window_reading).nits[..2], [300.0, 800.0]);
        assert_eq!(
@@ -549,6 +549,7 @@ mod tests {
        reading.luminance = Some(Reported {
            paper_white: 250,
            peak: 600,
+            peak_guessed: false,
        });
        // 150 nits under the reported paper white of 250: 0.6 of it.
        settings.hdr_ui_nits = 150;
@@ -584,6 +585,7 @@ mod tests {
            reading.luminance = Some(Reported {
                paper_white,
                peak: 1000,
+                peak_guessed: false,
            });
            let next = candidate(&settings, caps, reading, &published);
            let again = commit(&mut swapchain, &published, next, caps, &mut rejected);
@@ -729,6 +731,7 @@ mod tests {
                luminance: (hdr == Some(true)).then_some(Reported {
                    paper_white: 300,
                    peak: 800,
+                    peak_guessed: false,
                }),
                hdr,
            };
@@ -4,8 +4,7 @@

 use std::collections::BTreeMap;

-use horizon_render_pipeline::{Format, Kind};
-use horizon_shaders::{BufferObject, CustomImage};
+use horizon_shaders::{BufferObject, CustomImage, Format, Kind};

 pub(super) struct PackImage {
    pub(super) def: CustomImage,
@@ -18,8 +18,7 @@
 use std::collections::HashMap;

 use glam::{DMat4, DVec3};
-use horizon_render_pipeline::{BUFFERS, Format, Kind, SHADOW_COLORS};
-use horizon_shaders::{Group, Post};
+use horizon_shaders::{BUFFERS, Format, Group, Kind, Post, SHADOW_COLORS};
 use smallvec::SmallVec;

 use super::pack_draw::DrawUniforms;
@@ -893,7 +892,7 @@ fn depth_linear(interface: &horizon_shaders::Interface, linear: u8) -> [f32; 4]
 }

 fn source(name: &str, shadow_space: bool, shadow_pass: bool, watershadow: bool) -> Source {
-    let shadow_color = horizon_render_pipeline::shadow_color(name);
+    let shadow_color = horizon_shaders::shadow_color(name);
    let shadow_depth = match name {
        "shadowtex0" | "watershadow" | "shadowtex0HW" => Some(0),
        "shadowtex1" | "shadowtex1HW" => Some(1),
@@ -912,7 +911,7 @@ fn source(name: &str, shadow_space: bool, shadow_pass: bool, watershadow: bool)
            };
        }
    }
-    if shadow_space && horizon_render_pipeline::buffer_index(name).is_some() {
+    if shadow_space && horizon_shaders::buffer_index(name).is_some() {
        // colortex buffers are not this pass's.
        return Source::Dummy;
    }
@@ -926,7 +925,7 @@ fn source(name: &str, shadow_space: bool, shadow_pass: bool, watershadow: bool)
        "normals" => Source::Normals,
        "specular" => Source::Specular,
        horizon_shaders::WATER_MASK => Source::WaterMask,
-        n => horizon_render_pipeline::buffer_index(n).map_or(Source::Dummy, Source::Color),
+        n => horizon_shaders::buffer_index(n).map_or(Source::Dummy, Source::Color),
    }
 }

@@ -1583,7 +1582,7 @@ fn bindings(
            !unbound
                && (t.stage != pack_textures::stage(group)
                    || released.0 != t.stage
-                    || horizon_render_pipeline::buffer_index(&t.name)
+                    || horizon_shaders::buffer_index(&t.name)
                        .is_none_or(|b| released.1 & 1 << b == 0))
        });
        let image = pack
@@ -2433,7 +2432,7 @@ impl PackPost {
        let shadow_config = post.config.shadow.clone();
        let noise_size = post.config.noise_resolution.unwrap_or(256);
        let half_lives = post.config.half_lives;
-        for (name, ticks) in horizon_render_pipeline::HALF_LIVES.iter().zip(half_lives) {
+        for (name, ticks) in horizon_shaders::HALF_LIVES.iter().zip(half_lives) {
            if let Some(t) = ticks {
                notes.push(format!("`{name}` is {t} ticks"));
            }
@@ -602,7 +602,7 @@ pub(super) fn fixture_frame(hud: &HudBatch) -> Frame<'_> {
        outline: Vec::new(),
        outline_after_terrain: false,
        outline_high_contrast: false,
-        look: Default::default(),
+        pvp: Default::default(),
        debug_lines: &[],
        debug_lines_on_top: &[],
        debug_crosshair: &[],
@@ -440,7 +440,7 @@ fn fixture_frame(hud: &HudBatch) -> Frame<'_> {
        outline: Vec::new(),
        outline_after_terrain: false,
        outline_high_contrast: false,
-        look: Default::default(),
+        pvp: Default::default(),
        debug_lines: &[],
        debug_lines_on_top: &[],
        debug_crosshair: &[],
@@ -10,7 +10,7 @@
 //! a fit to one driver's values, not a rule Iris states. `RGBA4` and `RGBA2` read back the `RGBA8`
 //! bytes in the same probe, as Horizon's 8-bit buffers already do.

-use horizon_render_pipeline::{Format, Kind};
+use horizon_shaders::{Format, Kind};
 use naga::{BinaryOperator, Expression, Literal, MathFunction, Statement, VectorSize};

 /// The bits each channel keeps in a buffer of format `f`, for the formats that keep fewer than
@@ -409,7 +409,7 @@ fn frame(hud: &HudBatch) -> Frame<'_> {
        outline: Vec::new(),
        outline_after_terrain: false,
        outline_high_contrast: false,
-        look: Default::default(),
+        pvp: Default::default(),
        debug_lines: &[],
        debug_lines_on_top: &[],
        debug_crosshair: &[],
@@ -3,7 +3,7 @@
 //! with two sides that `shadowcomp` programs flip as composite programs flip colortex (6.1.6).
 //! Square, `shadowMapResolution` pixels.

-use horizon_render_pipeline::SHADOW_COLORS;
+use horizon_shaders::SHADOW_COLORS;

 type Ops<T> = wgpu::Operations<T>;
 type Color = wgpu::Color;
@@ -97,11 +97,7 @@ pub(super) fn stand_in(device: &wgpu::Device) -> wgpu::TextureView {
 }

 impl ShadowTargets {
-    pub fn reset_history(
-        &mut self,
-        device: &wgpu::Device,
-        shadow: &horizon_render_pipeline::Shadow,
-    ) {
+    pub fn reset_history(&mut self, device: &wgpu::Device, shadow: &horizon_shaders::Shadow) {
        let mut colors = 0;
        let mut doubled = 0;
        let formats = std::array::from_fn(|n| match &self.color[n] {
@@ -129,7 +125,7 @@ impl ShadowTargets {
    /// resolution is kept within the device's limit.
    pub fn new(
        device: &wgpu::Device,
-        shadow: &horizon_render_pipeline::Shadow,
+        shadow: &horizon_shaders::Shadow,
        formats: [wgpu::TextureFormat; SHADOW_COLORS],
        colors: u16,
        doubled: u16,
@@ -1,8 +1,7 @@
 //! A shader pack's custom textures (`texture.<stage>.<name>`, `texture.noise`) on the GPU, and
 //! which of them a program's sampler reads.

-use horizon_render_pipeline::Kind;
-use horizon_shaders::{CustomTexture, Group, Texels, Texture, TextureDim, TextureSource};
+use horizon_shaders::{CustomTexture, Group, Kind, Texels, Texture, TextureDim, TextureSource};

 /// What a custom texture is once uploaded: an image of ours, or one the game already has.
 pub(super) enum Image {
@@ -119,12 +118,12 @@ pub(super) fn find(textures: &[PackTexture], group: Group, ty: &str, name: &str)
    } else {
        wgpu::TextureViewDimension::D2
    };
-    let buffer = horizon_render_pipeline::buffer_index(name);
+    let buffer = horizon_shaders::buffer_index(name);
    let staged = textures.iter().position(|t| {
        t.stage == stage(group)
            && t.dimension == dimension
            && (t.name == name
-                || buffer.is_some() && horizon_render_pipeline::buffer_index(&t.name) == buffer)
+                || buffer.is_some() && horizon_shaders::buffer_index(&t.name) == buffer)
    });
    staged.or_else(|| {
        textures.iter().position(|t| {
@@ -28,7 +28,7 @@
 //! [-w, w], and the depth buffers packs read hold GL window depth.

 use glam::{DMat4, DVec3, Mat4, Vec3, Vec4};
-use horizon_render_pipeline::Shadow;
+use horizon_shaders::Shadow;

 use super::Frame;

@@ -440,7 +440,7 @@ pub struct FrameUniforms {
    center_depth: Option<f32>,
    /// The pack's shadow settings (7.1).
    pub shadow: Shadow,
-    /// The pack's smoothing half-lives in ticks (`horizon_render_pipeline::HALF_LIVES`).
+    /// The pack's smoothing half-lives in ticks (`horizon_shaders::HALF_LIVES`).
    pub half_lives: [Option<f32>; 4],
 }

@@ -2664,7 +2664,7 @@ pub(super) mod initial_history_tests {
            outline: Vec::new(),
            outline_after_terrain: false,
            outline_high_contrast: false,
-            look: Default::default(),
+            pvp: Default::default(),
            debug_lines: &[],
            debug_lines_on_top: &[],
            debug_crosshair: &[],
@@ -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());
+    }
+}
@@ -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();
+    }
+}
@@ -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"))]
@@ -30,6 +30,22 @@ fn marker_driver(text: &str) -> &str {
 pub struct Reported {
    pub paper_white: u32,
    pub peak: u32,
+    /// The peak is the display's own claim (DXGI's `MaxLuminance`, mostly its EDID figure),
+    /// which often runs high: Auto still uses it, but the HDR page asks to calibrate.
+    pub peak_guessed: bool,
+}
+
+/// Whether HDR is set up for the display, and whether the player kept the system's setup.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum HdrSetup {
+    /// The system says nothing: the player calibrates.
+    Unknown,
+    /// The system says, but only guesses the peak: the player calibrates.
+    Guessed,
+    /// Peak Brightness and Paper White follow the system.
+    Automatic,
+    /// The system said, and the player changed them anyway.
+    Changed,
 }

 /// The top of Peak Brightness's scale: `peak_nits_at(PEAK_STEPS)` is PQ's 10 000 nits.
@@ -1207,6 +1223,15 @@ impl Graphics {
            n => n,
        }
    }
+    /// How HDR is set up for the display the system `reported`.
+    pub fn hdr_setup(&self, reported: Option<Reported>) -> HdrSetup {
+        match reported {
+            None => HdrSetup::Unknown,
+            Some(_) if self.hdr_peak != 0 || self.hdr_paper_white != 0 => HdrSetup::Changed,
+            Some(r) if r.peak_guessed => HdrSetup::Guessed,
+            Some(_) => HdrSetup::Automatic,
+        }
+    }
    /// The black level, in nits. Not the system's: files from before saved 0 for that
    /// (Auto), and a reported black would lift every display's shadows by default.
    pub fn black_level_nits(&self) -> f32 {
@@ -1320,6 +1345,7 @@ mod tests {
        let reported = Some(Reported {
            paper_white: 300,
            peak: 1000,
+            peak_guessed: false,
        });
        assert_eq!(g.ui_nits(reported), 300);
        g.hdr_paper_white = 120;
@@ -1328,6 +1354,33 @@ mod tests {
        assert_eq!((g.ui_nits(None), g.ui_nits(reported)), (400, 400));
    }

+    #[test]
+    fn hdr_setup_asks_to_calibrate_where_the_peak_is_guessed() {
+        let wayland = Reported {
+            paper_white: 203,
+            peak: 1015,
+            peak_guessed: false,
+        };
+        let windows = Reported {
+            paper_white: 400,
+            peak: 1000,
+            peak_guessed: true,
+        };
+        let mut g = Graphics::default();
+        assert_eq!(g.hdr_setup(None), HdrSetup::Unknown);
+        assert_eq!(g.hdr_setup(Some(wayland)), HdrSetup::Automatic);
+        assert_eq!(g.hdr_setup(Some(windows)), HdrSetup::Guessed);
+        // Auto still takes the guess, over the 1000-nit default.
+        assert_eq!(g.peak_nits(Some(windows)), 1000);
+        assert_eq!(g.paper_white_nits(Some(windows)), 400);
+        for (peak, paper_white) in [(800, 0), (0, 240)] {
+            (g.hdr_peak, g.hdr_paper_white) = (peak, paper_white);
+            assert_eq!(g.hdr_setup(Some(windows)), HdrSetup::Changed);
+            assert_eq!(g.hdr_setup(Some(wayland)), HdrSetup::Changed);
+            assert_eq!(g.hdr_setup(None), HdrSetup::Unknown);
+        }
+    }
+
    #[test]
    fn hdr_modes_keep_boolean_files_and_round_trip_auto() {
        assert_eq!(Graphics::parse("").hdr, HdrMode::Off);
@@ -8,7 +8,8 @@ use crate::{
    gfx::EffectiveOutput,
    graphics::{
        EntityCullingMode, FarDetail, FrameGeneration, GpuCullingMode, GraphicsApi, HdrMode,
-        LeafCullingMode, Overlay, Pacing, ParticleCullingMode, PresentMode, Preset, Upscaling,
+        HdrSetup as Setup, LeafCullingMode, Overlay, Pacing, ParticleCullingMode, PresentMode,
+        Preset, Upscaling,
    },
    graphics_style::Cost,
    lang,
@@ -675,28 +676,9 @@ const LOD_STEPS: [u32; 24] = [
    crate::lod::MAX_CHUNKS,
 ];

-/// Whether the system set HDR up for the display, and whether the player kept it.
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
-enum Setup {
-    /// The system says nothing: the player calibrates.
-    Unknown,
-    /// Peak Brightness and Paper White follow the system.
-    Automatic,
-    /// The system said, and the player changed them anyway.
-    Changed,
-}
 /// `out`: the output of the renderer the settings are shown for, with what its display reports.
 fn setup(s: &Settings, out: &EffectiveOutput) -> Setup {
-    setup_of(&s.horizon, out.reported.is_some())
-}
-fn setup_of(g: &crate::graphics::Graphics, reported: bool) -> Setup {
-    if !reported {
-        Setup::Unknown
-    } else if g.hdr_peak == 0 && g.hdr_paper_white == 0 {
-        Setup::Automatic
-    } else {
-        Setup::Changed
-    }
+    s.horizon.hdr_setup(out.reported)
 }
 /// What the HDR page says while HDR output is held back on this window's graphics driver
 /// (`EffectiveOutput::held`): picking a mode tries again (`H::cycle`).
@@ -714,13 +696,19 @@ fn description(
        (Item::Horizon(H::HdrCalibrate), Setup::Unknown) => {
            "Your display didn't say how bright it gets: calibrate to set it up."
        }
+        (Item::Horizon(H::HdrCalibrate), Setup::Guessed) => {
+            "Your display's reported peak is often too high: calibrate to set it up."
+        }
        (Item::Horizon(H::HdrCalibrate), Setup::Automatic) => {
            "Already set up for your display. Only calibrate if HDR looks wrong."
        }
        (Item::Horizon(H::HdrCalibrate), Setup::Changed) => {
            "Puts Peak Brightness and Paper White back to your display's setup."
        }
-        (Item::Horizon(H::HdrPeak | H::HdrPaperWhite), Setup::Automatic | Setup::Changed) => {
+        // A guessed peak's Auto is what calibration replaced; paper white is the player's own.
+        (Item::Horizon(h @ (H::HdrPeak | H::HdrPaperWhite)), Setup::Automatic | Setup::Changed)
+            if h == H::HdrPaperWhite || out.reported.is_some_and(|r| !r.peak_guessed) =>
+        {
            "Set up for your display. Leave on Auto unless it looks wrong."
        }
        (Item::Horizon(H::GpuCulling), _) if s.horizon.gpu_culling == GpuCullingMode::Auto => {
@@ -944,7 +932,7 @@ impl H {
            H::FrameGeneration => labelled("Frame Generation", g.frame_generation.label()),
            H::Hdr => labelled("HDR", g.hdr.label()),
            H::HdrCalibrate => Text::literal(lang::get(match setup(s, out) {
-                Setup::Unknown => "Calibrate...",
+                Setup::Unknown | Setup::Guessed => "Calibrate...",
                Setup::Automatic => "Calibrate Anyway...",
                Setup::Changed => "Use Automatic Setup",
            })),
@@ -1122,7 +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.");
@@ -1153,6 +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() =>
            {
@@ -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();
@@ -120,14 +163,86 @@ fn auto_levels_and_setup_read_their_own_renderers_report() {
    assert_eq!(label(H::HdrCalibrate, &silent), "Calibrate...");
 }

+/// The setup rows' label and description for each kind of report: none, a compositor's
+/// (Wayland), and Windows', whose peak is the display's own guess.
 #[test]
-fn hdr_setup_follows_what_the_system_reported() {
-    let mut g = crate::graphics::Graphics::default();
-    assert_eq!(setup_of(&g, false), Setup::Unknown);
-    assert_eq!(setup_of(&g, true), Setup::Automatic);
-    g.hdr_paper_white = 80;
-    assert_eq!(setup_of(&g, true), Setup::Changed);
-    assert_eq!(setup_of(&g, false), Setup::Unknown);
+fn the_setup_rows_ask_to_calibrate_unless_the_system_set_the_display_up() {
+    let trusted = offering(true, Some(true));
+    let mut guessed = trusted;
+    guessed.reported = guessed.reported.map(|r| crate::graphics::Reported {
+        peak_guessed: true,
+        ..r
+    });
+    let rows = |s: &Settings, out: &EffectiveOutput| {
+        [H::HdrCalibrate, H::HdrPeak, H::HdrPaperWhite].map(|h| {
+            let item = Item::Horizon(h);
+            (item.label(s, out).plain(), description(item, s, out, "-"))
+        })
+    };
+    let calibrate = "Calibrate...";
+    let set_up = "Set up for your display. Leave on Auto unless it looks wrong.";
+    let mut s = Settings::default();
+    s.horizon.hdr = HdrMode::On;
+    let none = (
+        calibrate.into(),
+        "Your display didn't say how bright it gets: calibrate to set it up.",
+    );
+    assert_eq!(
+        rows(&s, &NONE),
+        [
+            none.clone(),
+            ("Peak Brightness: Auto (1000)".into(), "-"),
+            ("Paper White: Auto (203)".into(), "-"),
+        ]
+    );
+    assert_eq!(
+        rows(&s, &guessed),
+        [
+            (
+                calibrate.into(),
+                "Your display's reported peak is often too high: calibrate to set it up."
+            ),
+            ("Peak Brightness: Auto (1000)".into(), "-"),
+            ("Paper White: Auto (400)".into(), "-"),
+        ]
+    );
+    assert_eq!(
+        rows(&s, &trusted),
+        [
+            (
+                "Calibrate Anyway...".into(),
+                "Already set up for your display. Only calibrate if HDR looks wrong."
+            ),
+            ("Peak Brightness: Auto (1000)".into(), set_up),
+            ("Paper White: Auto (400)".into(), set_up),
+        ]
+    );
+    // Calibrated or set by hand, either report offers its automatic setup back.
+    s.horizon.hdr_peak = 800;
+    // Peak's Auto stays a guess on Windows: only Paper White is said to be set up there.
+    let changed = |peak| {
+        [
+            (
+                "Use Automatic Setup".into(),
+                "Puts Peak Brightness and Paper White back to your display's setup.",
+            ),
+            ("Peak Brightness: 800".into(), peak),
+            ("Paper White: Auto (400)".into(), set_up),
+        ]
+    };
+    assert_eq!(rows(&s, &guessed), changed("-"));
+    assert_eq!(rows(&s, &trusted), changed(set_up));
+    assert_eq!(rows(&s, &NONE)[0], none);
+    let mut ui = ui();
+    ui.screen.output = guessed;
+    let at = |[x, y, ..]: [f32; 4]| (x + 8.0, y + 4.0);
+    let calibrate = row(&mut ui, &s, Item::Horizon(H::HdrCalibrate));
+    assert_eq!(press(&mut ui, &mut s, at(calibrate)), [CLICK, CHANGED]);
+    assert_eq!((s.horizon.hdr_peak, s.horizon.hdr_paper_white), (0, 0));
+    assert_eq!(
+        press(&mut ui, &mut s, at(calibrate)),
+        [CLICK, Output::Push(OptionsPage::HdrCalibration)]
+    );
 }

 /// UI Brightness reads as Paper White does, in nits apart from it: Auto shows the paper white
@@ -67,7 +67,6 @@ mod jei_sprites;
 pub mod jigsaw_block;
 pub mod keypad;
 pub mod terrain_model;
-pub use horizon_polytone::colors as polytone_colors;
 pub use horizon_polytone::creative_tabs as polytone_creative_tabs;
 pub use horizon_world::json_folder;
 pub mod level_loading;
@@ -89,6 +88,8 @@ pub mod options_fixes;
 pub mod options_ui;
 pub mod overlay;
 pub mod pack_browser;
+pub mod pack_formats;
+pub mod pack_hooks;
 pub mod pack_options_ui;
 pub mod pack_palette;
 pub mod pack_screen;
@@ -2593,8 +2593,7 @@ impl Lod {
        self.returned_at = std::time::Instant::now();
        let nodes = &self.plan.nodes;
        self.mesh_samples.retain(|key| nodes.contains(key));
-        // Queued tiles the view left are not sampled (a running one is
-        // dropped when it finishes, `finish_sample`).
+        // Queued tiles the view left are not sampled; a running one is dropped (`finish_sample`).
        drop_queued_samples(&self.shared, &mut self.pending, |key| {
            self.plan.nodes.contains(key)
        });
@@ -2680,6 +2679,7 @@ impl Lod {
            }
            if let Some((columns, mask)) = self.kept.take(&key) {
                self.ready.insert(key, columns);
+                self.sync_sample(key);
                if let Some(mask) = mask {
                    self.detail_masks.insert(key, mask);
                }
@@ -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.
@@ -339,6 +339,7 @@ impl Opt {
            Opt::SharePresence => "options.sharePresence",
            Opt::DirectionalAudio => "options.directionalAudio",
            Opt::MusicToast => "options.musicToast",
+            Opt::Page(page, row) => pages::slider_caption(page, row),
        }
    }
    pub(crate) fn kind(self, s: &Settings) -> Kind {
@@ -402,6 +403,7 @@ impl Opt {
            Opt::PadLookDeadzone => unit(s.controller.look_deadzone, 0.0, 0.5),
            Opt::PadTriggerThreshold => unit(s.controller.trigger_threshold, 0.1, 0.9),
            Opt::SprintWindow => unit(s.sprint_window as f32, 0.0, 10.0),
+            Opt::Page(page, row) => pages::slider_kind(page, row),
            _ => Kind::Cycle,
        }
    }
@@ -878,6 +880,7 @@ impl Opt {
                gamepad::TextKeyboard::Horizon => "horizon.options.keyboard.horizon",
                gamepad::TextKeyboard::Steam => "horizon.options.keyboard.steam",
            }),
+            Opt::Page(page, row) => pages::slider_text(page, row),
            _ => Text::empty(),
        }
    }
@@ -952,6 +955,7 @@ impl Opt {
            Opt::PadLookDeadzone => s.controller.look_deadzone = step(0.0, 50.0) / 100.0,
            Opt::PadTriggerThreshold => s.controller.trigger_threshold = step(10.0, 90.0) / 100.0,
            Opt::SprintWindow => s.sprint_window = step(0.0, 10.0) as i32,
+            Opt::Page(page, row) => pages::slide(page, row, v),
            _ => {}
        }
        if self.affects_preset() {
@@ -1624,8 +1628,6 @@ pub struct OptionsUi {
    /// The native mod's key waiting: (mod, key) in `mods.installed`, or a registered page's
    /// (page, row) ([`pages::PAGE_KEY`]).
    selected_native_key: Option<(usize, usize)>,
-    /// The pages crates registered (`horizon_hooks::pages`).
-    pages: &'static [&'static dyn horizon_hooks::pages::Page],
    /// Bindings: the action waiting for a pad button.
    pub selected_pad_action: Option<&'static str>,
    /// The glyphs menus show (`Glyphs::of`: the setting, else the pad's family, and a Nintendo
@@ -1737,7 +1739,6 @@ impl Default for OptionsUi {
            scrollbar_drag_y: None,
            selected_key: None,
            selected_native_key: None,
-            pages: horizon_hooks::pages::engine::all(),
            selected_pad_action: None,
            pad_glyphs: crate::pad_glyph::Glyphs::default(),
            pad_driving: false,
@@ -1869,25 +1870,6 @@ fn wide_extras(s: &Settings, width: impl Fn(&str) -> f32) -> Vec<crate::extras::
        })
        .collect()
 }
-/// What a button opening one of Horizon's pages says on hover.
-fn horizon_page_tooltip(page: Page) -> Option<&'static str> {
-    Some(match page {
-        Page::Horizon => "horizon.pages.settings.tooltip",
-        Page::Studio => "horizon.pages.studio.tooltip",
-        Page::Graphics => "horizon.pages.graphics.tooltip",
-        Page::GraphicsAdvanced => "horizon.pages.graphics_advanced.tooltip",
-        Page::Controller => "horizon.pages.controller.tooltip",
-        Page::Extras => "horizon.pages.extras.tooltip",
-        Page::Pvp => "horizon.pages.pvp.tooltip",
-        Page::Agent => "horizon.pages.agent.tooltip",
-        Page::SplitProfiles => "horizon.pages.split_profiles.tooltip",
-        Page::ShaderPacks => "horizon.pages.shader_packs.tooltip",
-        Page::Mods => "horizon.pages.mods.tooltip",
-        Page::SplitSetup => "horizon.pages.split_setup.tooltip",
-        Page::Music => "horizon.pages.music.tooltip",
-        _ => return None,
-    })
-}
 /// Rows of an OptionsList: (big?, options) or a header.
 enum Row {
    Big(Opt),
@@ -1907,14 +1889,17 @@ fn tooltip_text(s: &Settings, wd: &Widget) -> Option<Text> {
            return None;
        };
        let key = opt.tooltip_key(s);
-        return lang::has(&key).then(|| tr(&key));
+        let Opt::Page(page, row) = opt else {
+            return lang::has(&key).then(|| tr(&key));
+        };
+        return pages::tooltip(*page, *row);
    };
    let mut tip = None;
    if let Act::Extra(item) = act {
        tip = Some(Text::literal(item.description_text()));
    }
    if let Act::Push(page) = act
-        && let Some(text) = horizon_page_tooltip(*page)
+        && let Some(text) = pages::horizon_page_tooltip(*page)
    {
        tip = Some(tr(text));
    }
@@ -1934,6 +1919,7 @@ fn tooltip_text(s: &Settings, wd: &Widget) -> Option<Text> {
    }
    match act {
        Act::Cycle(opt) if !opt.available() => Some(tr("horizon.options.unavailable")),
+        Act::PageRow(page, row) => pages::tooltip(*page, *row),
        Act::ToggleMod(i) => match s.mods.installed.get(*i) {
            Some(installed) => {
                let description = installed
@@ -8,9 +8,88 @@ use horizon_hooks::pages as added;
 /// `selected_key` while a registered page's key waits (`selected_native_key`: page, row).
 pub(super) const PAGE_KEY: &str = "horizon.pageKey";

+#[cfg(test)]
+thread_local! {
+    /// A test's own pages, instead of the game's registered ones: each test runs on its thread.
+    static TEST_PAGES: std::cell::Cell<Option<&'static [&'static dyn added::Page]>> =
+        const { std::cell::Cell::new(None) };
+}
+
+/// The pages crates registered.
+fn registered() -> &'static [&'static dyn added::Page] {
+    #[cfg(test)]
+    if let Some(pages) = TEST_PAGES.get() {
+        return pages;
+    }
+    added::engine::all()
+}
+
 /// A registered page's title (a translation key).
 pub(super) fn title(page: usize) -> &'static str {
-    added::engine::all().get(page).map_or("", |p| p.title())
+    registered().get(page).map_or("", |p| p.title())
+}
+
+/// Row `r` of a registered page, as it is now.
+fn row(page: usize, r: usize) -> Option<added::Row> {
+    let mut rows = Vec::new();
+    registered().get(page)?.rows(&mut rows);
+    rows.into_iter().nth(r)
+}
+
+/// A registered page's slider ([`Opt::Page`]): its caption (a translation key).
+pub(super) fn slider_caption(page: usize, r: usize) -> &'static str {
+    match row(page, r) {
+        Some(added::Row::Slider { label, .. }) => label,
+        _ => "",
+    }
+}
+
+/// A registered page's slider: its position.
+pub(super) fn slider_kind(page: usize, r: usize) -> Kind {
+    match row(page, r) {
+        Some(added::Row::Slider { value, .. }) => Kind::Slider(value.clamp(0.0, 1.0)),
+        _ => Kind::Cycle,
+    }
+}
+
+/// A registered page's slider: the value its message shows after the caption.
+pub(super) fn slider_text(page: usize, r: usize) -> Text {
+    match row(page, r) {
+        Some(added::Row::Slider { text, .. }) => label_text(text),
+        _ => Text::empty(),
+    }
+}
+
+/// A registered page's slider moved.
+pub(super) fn slide(page: usize, r: usize, value: f32) {
+    if let Some(registered) = registered().get(page) {
+        registered.act(r, added::Act::Slide(value));
+    }
+}
+
+/// What a registered page's row says on hover.
+pub(super) fn tooltip(page: usize, r: usize) -> Option<Text> {
+    registered().get(page)?.tooltip(r).map(label_text)
+}
+
+/// What a button opening one of Horizon's pages says on hover.
+pub(super) fn horizon_page_tooltip(page: Page) -> Option<&'static str> {
+    Some(match page {
+        Page::Horizon => "horizon.pages.settings.tooltip",
+        Page::Studio => "horizon.pages.studio.tooltip",
+        Page::Graphics => "horizon.pages.graphics.tooltip",
+        Page::GraphicsAdvanced => "horizon.pages.graphics_advanced.tooltip",
+        Page::Controller => "horizon.pages.controller.tooltip",
+        Page::Extras => "horizon.pages.extras.tooltip",
+        Page::Pvp => "horizon.pages.pvp.tooltip",
+        Page::Agent => "horizon.pages.agent.tooltip",
+        Page::SplitProfiles => "horizon.pages.split_profiles.tooltip",
+        Page::ShaderPacks => "horizon.pages.shader_packs.tooltip",
+        Page::Mods => "horizon.pages.mods.tooltip",
+        Page::SplitSetup => "horizon.pages.split_setup.tooltip",
+        Page::Music => "horizon.pages.music.tooltip",
+        _ => return None,
+    })
 }

 fn label_text(label: added::Label) -> Text {
@@ -66,8 +145,7 @@ impl OptionsUi {

    /// The entries of the pages registered for Horizon Settings, two to a row like the engine's.
    fn added_entries(&self, rows: &mut Vec<Row>) {
-        let mut entries = self
-            .pages
+        let mut entries = registered()
            .iter()
            .enumerate()
            .filter(|(_, page)| page.place() == added::Place::HorizonSettings)
@@ -79,15 +157,43 @@ impl OptionsUi {

    /// A registered page's rows, asked of it each time the page is drawn.
    pub(super) fn added_rows(&self, page: usize) -> Vec<Row> {
-        let Some(registered) = self.pages.get(page) else {
+        let Some(registered) = registered().get(page) else {
            return Vec::new();
        };
        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(_) | added::Row::Field { .. } => 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 {
@@ -98,7 +204,11 @@ impl OptionsUi {
            added::Row::Note(text) => Row::Note(text),
            added::Row::Toggle { label, on } => wide(generic(label, on_off(on))),
            added::Row::Cycle { label, value } => wide(generic(label, label_text(value))),
-            added::Row::Button { label } => wide(tr(label)),
+            added::Row::Slider { .. } => Row::Big(Opt::Page(page, r)),
+            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)
@@ -120,7 +230,7 @@ impl OptionsUi {

    /// A registered page's row was pressed: a key row waits for a key, any other row hears it.
    pub(super) fn page_act(&mut self, page: usize, r: usize, shift: bool) -> Vec<Event> {
-        let Some(registered) = self.pages.get(page) else {
+        let Some(registered) = registered().get(page) else {
            return Vec::new();
        };
        let mut rows = Vec::new();
@@ -199,7 +309,7 @@ impl OptionsUi {
    ) -> Vec<Event> {
        let (i, k) = self.selected_native_key.take().unwrap_or_default();
        if name == PAGE_KEY {
-            if let Some(page) = self.pages.get(i) {
+            if let Some(page) = registered().get(i) {
                page.act(k, added::Act::Bind(value));
            }
            return vec![Event::Changed];
@@ -221,11 +331,12 @@ mod tests {
    use super::*;
    use std::sync::Mutex;

-    /// A page with a heading, a switch, a number that steps either way and a key.
+    /// A page with a heading, a switch, a number that steps either way, a key and a volume.
    struct Sample {
        on: Mutex<bool>,
        step: Mutex<i32>,
        key: Mutex<String>,
+        volume: Mutex<f32>,
    }

    impl added::Page for Sample {
@@ -252,6 +363,12 @@ mod tests {
                label: "test.sample.key",
                key: self.key.lock().unwrap().clone(),
            });
+            let volume = *self.volume.lock().unwrap();
+            rows.push(added::Row::Slider {
+                label: "test.sample.volume",
+                value: volume,
+                text: added::Label::Value(format!("{}%", (volume * 100.0).round())),
+            });
        }
        fn act(&self, row: usize, act: added::Act) {
            match (row, act) {
@@ -262,15 +379,20 @@ mod tests {
                (2, added::Act::Press) => *self.step.lock().unwrap() += 1,
                (2, added::Act::PressBack) => *self.step.lock().unwrap() -= 1,
                (3, added::Act::Bind(key)) => *self.key.lock().unwrap() = key,
+                (4, added::Act::Slide(v)) => *self.volume.lock().unwrap() = v,
                other => panic!("row and act the page doesn't expect: {other:?}"),
            }
        }
+        fn tooltip(&self, row: usize) -> Option<added::Label> {
+            (row == 1).then_some(added::Label::Key("test.sample.switch.tooltip"))
+        }
    }

    static SAMPLE: Sample = Sample {
        on: Mutex::new(false),
        step: Mutex::new(0),
        key: Mutex::new(String::new()),
+        volume: Mutex::new(0.0),
    };
    static PAGES: [&dyn added::Page; 1] = [&SAMPLE];

@@ -297,10 +419,8 @@ mod tests {
    #[test]
    fn a_registered_page_opens_from_horizon_settings_and_hears_its_rows() {
        let mut s = Settings::default();
-        let mut ui = OptionsUi {
-            pages: &PAGES,
-            ..OptionsUi::default()
-        };
+        TEST_PAGES.set(Some(&PAGES));
+        let mut ui = OptionsUi::default();
        ui.show(Page::Horizon);
        press(&mut ui, &mut s, Act::Push(Page::Added(0)), false);
        assert_eq!(ui.page(), Page::Added(0));
@@ -323,5 +443,133 @@ mod tests {
        assert_eq!(events, [Event::Changed]);
        assert_eq!(*SAMPLE.key.lock().unwrap(), "key.keyboard.z");
        assert_eq!(ui.selected_key, None);
+        // The volume is one of the screen's own sliders: dragged to its middle, then let go.
+        let size = (480.0, 240.0);
+        let (widgets, ..) = ui.layout(&s, size.0, size.1);
+        let slider = widgets
+            .iter()
+            .find(|w| {
+                matches!(
+                    w.kind,
+                    WKind::Slider {
+                        opt: Opt::Page(0, 4),
+                        ..
+                    }
+                )
+            })
+            .expect("the volume's slider");
+        let (x, y) = (slider.x + slider.w / 2.0, slider.y + 1.0);
+        ui.click(&mut s, &atlas, x, y, size, [480, 240], false, false);
+        let volume = *SAMPLE.volume.lock().unwrap();
+        assert!((0.45..0.55).contains(&volume), "{volume}");
+        assert!(ui.release().contains(&Event::Changed));
+        // The slider shows the page's value once let go.
+        let (widgets, ..) = ui.layout(&s, size.0, size.1);
+        let shown = widgets.iter().find_map(|w| match w.kind {
+            WKind::Slider {
+                opt: Opt::Page(0, 4),
+                value,
+                ..
+            } => Some(value),
+            _ => None,
+        });
+        assert_eq!(shown, Some(volume));
+        // The page's tooltip for its switch.
+        let switch = widgets
+            .iter()
+            .find(|w| {
+                matches!(
+                    &w.kind,
+                    WKind::Button {
+                        act: Act::PageRow(0, 1),
+                        ..
+                    }
+                )
+            })
+            .expect("the switch");
+        assert_eq!(
+            tooltip_text(&s, switch).map(|t| t.plain()),
+            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"
+        );
    }
 }
@@ -0,0 +1,79 @@
+//! Polytone's custom colours (`horizon_polytone::colors`, `colors.json` or `color.properties`)
+//! as the engine's pack colours ([`crate::pack_palette::PackColors`]).
+use std::path::Path;
+
+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);
+    let by_dye = |f: &dyn Fn(&str) -> Option<u32>| std::array::from_fn(|i| f(DYES[i].0));
+    let env = colors.env;
+    pack_palette::PackColors {
+        dye_diffuse: by_dye(&|name| colors.dye(name, "diffuse")),
+        dye_text: by_dye(&|name| colors.dye(name, "text")),
+        sheep: by_dye(&|name| colors.sheep(name)),
+        redstone: std::array::from_fn(|i| colors.redstone(i as u8)),
+        effects: colors.effects(),
+        entity_shadows: colors.entity_shadows(),
+        xp_bar: colors.xp_bar(),
+        env: Environment {
+            powder_snow_fog: env.powder_snow_fog,
+            blindness_fog_distance: env.blindness_fog_distance,
+            darkness_fog_distance: env.darkness_fog_distance,
+            boss_fog_distance: env.boss_fog_distance,
+            water_fog_brightening: env.water_fog_brightening,
+            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),
+        },
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::pack_palette::{diffuse, redstone, sheep_wool, text};
+
+    #[test]
+    fn a_pack_recolours_only_what_it_names() {
+        // Dyes no other test draws: the table is process-wide.
+        let dir = std::env::temp_dir().join(format!("pack-dyes-{}", std::process::id()));
+        let polytone = dir.join("assets/obs/polytone");
+        std::fs::create_dir_all(&polytone).unwrap();
+        std::fs::write(
+            polytone.join("colors.json"),
+            r#"{"dye": {"cyan": {"diffuse": "00ff00", "text": "0000ff"}}, "sheep": {"pink": "2040ff"}, "redstone": {"7": "0x123456"}}"#,
+        )
+        .unwrap();
+        crate::pack_palette::set(&read(&dir));
+        let (cyan, pink, purple) = (9, 6, 10);
+        assert_eq!(diffuse(cyan), 0x00ff00);
+        assert_eq!(text(cyan), 0x0000ff);
+        assert_eq!(sheep_wool(pink as u8), 0x2040ff);
+        // Wool reads vanilla's dye, not the pack's diffuse: 75% of 0x169C9C.
+        assert_eq!(sheep_wool(cyan as u8), 0x107575);
+        assert_eq!(diffuse(purple), 0x8932B8);
+        assert_eq!(text(purple), 0xA020F0);
+        assert_eq!((redstone(7), redstone(15)), (Some(0x123456), None));
+        crate::pack_palette::set(&Default::default());
+        assert_eq!(redstone(7), None);
+        assert_eq!(diffuse(cyan), 0x169C9C);
+        assert_eq!(sheep_wool(pink as u8), 0xB6687F);
+        std::fs::remove_dir_all(&dir).ok();
+    }
+}
@@ -0,0 +1,252 @@
+//! OptiFine custom skies (`horizon_optifine::sky`) on the engine's sky layers
+//! ([`crate::custom_sky`]): a pack's layers with their decoded textures, read once with the pack,
+//! and each frame's choice of layers, their brightness and rotation. A pack without
+//! `optifine/sky` has none, and the sky stays vanilla.
+
+use std::path::Path;
+
+use glam::{Mat4, Vec3};
+use horizon_optifine::sky::{Blend, Conditions, Now, Skies, SkyLayer, Transition};
+
+use crate::custom_sky::{self as engine, Draw, Image, SkyLayers, State};
+
+/// The pack's layers, by world, with one texture per layer (`images[i]` for the `i`th layer
+/// over all worlds, in `worlds` order).
+#[derive(Default)]
+pub struct CustomSky {
+    worlds: Vec<(i32, Vec<SkyLayer>)>,
+    pub images: Vec<Image>,
+}
+
+/// Textures past this many texels in all are left out (a skybox is a few megapixels at most).
+const TEXEL_BUDGET: u64 = 64 << 20;
+
+impl CustomSky {
+    /// The custom skies of the overlay at `root`. A layer whose texture does not decode is
+    /// dropped with a warning.
+    pub fn load(root: &Path) -> Self {
+        let skies = Skies::scan(root);
+        let mut out = Self::default();
+        let mut texels = 0u64;
+        for (world, sky) in skies.worlds {
+            let mut layers = Vec::new();
+            for layer in sky.layers {
+                match crate::hud::decode(&root.join(&layer.source)) {
+                    Ok((width, height, rgba))
+                        if texels + u64::from(width) * u64::from(height) <= TEXEL_BUDGET =>
+                    {
+                        texels += u64::from(width) * u64::from(height);
+                        out.images.push(Image {
+                            width,
+                            height,
+                            rgba,
+                        });
+                        layers.push(layer);
+                    }
+                    Ok(_) => log::warn!("{}: past the custom sky's texture budget", layer.source),
+                    Err(e) => log::warn!("{}: {e:#}", layer.source),
+                }
+            }
+            if !layers.is_empty() {
+                out.worlds.push((world, layers));
+            }
+        }
+        out
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.worlds.is_empty()
+    }
+}
+
+/// The engine's sky blend for OptiFine's.
+fn blend(blend: Blend) -> engine::Blend {
+    match blend {
+        Blend::Add => engine::Blend::Add,
+        Blend::Subtract => engine::Blend::Subtract,
+        Blend::Multiply => engine::Blend::Multiply,
+        Blend::Dodge => engine::Blend::Dodge,
+        Blend::Burn => engine::Blend::Burn,
+        Blend::Screen => engine::Blend::Screen,
+        Blend::Replace => engine::Blend::Replace,
+        Blend::Overlay => engine::Blend::Overlay,
+        Blend::Alpha => engine::Blend::Alpha,
+    }
+}
+
+impl SkyLayers for CustomSky {
+    fn images(&self) -> &[Image] {
+        &self.images
+    }
+
+    /// Whether `world` has layers (`0` the Overworld, `1` the End).
+    fn has(&self, world: i32) -> bool {
+        self.worlds.iter().any(|(w, _)| *w == world)
+    }
+
+    /// The layers whose conditions hold, eased over their `transition`, at the brightness of
+    /// their fade times.
+    fn draws(
+        &self,
+        world: i32,
+        conditions: &engine::Conditions,
+        sun_turns: f32,
+        seconds: f32,
+        state: &mut State,
+        out: &mut Vec<Draw>,
+    ) {
+        let conditions = &Conditions {
+            day_time: conditions.day_time,
+            weather: match conditions.weather {
+                engine::Weather::Clear => Now::Clear,
+                engine::Weather::Rain => Now::Rain,
+                engine::Weather::Thunder => Now::Thunder,
+            },
+            biome: conditions.biome,
+            y: conditions.y,
+        };
+        out.clear();
+        let mut first = 0;
+        let mut found = None;
+        for (w, layers) in &self.worlds {
+            if *w == world {
+                found = Some(layers);
+                break;
+            }
+            first += layers.len();
+        }
+        let Some(layers) = found else {
+            state.world = None;
+            return;
+        };
+        // A new world (or pack) starts each layer where its conditions put it: no fade in.
+        let snap = state.world != Some(world) || state.eased.len() != layers.len();
+        if snap {
+            state.world = Some(world);
+            state.eased.clear();
+            state.eased.resize(layers.len(), 0.0);
+        }
+        for (i, (layer, eased)) in layers.iter().zip(&mut state.eased).enumerate() {
+            let target = if layer.shows(conditions) { 1.0 } else { 0.0 };
+            let shown = if snap {
+                *eased = target;
+                target
+            } else {
+                let mut t = Transition { value: *eased };
+                *eased = t.step(target, seconds, layer.transition);
+                *eased
+            };
+            let brightness = shown * layer.brightness(conditions.day_time);
+            if brightness <= 0.0 {
+                continue;
+            }
+            let turns = layer.turns(conditions.day_time, sun_turns);
+            let rotation = if turns == 0.0 {
+                Mat4::IDENTITY
+            } else {
+                Mat4::from_axis_angle(Vec3::from_array(layer.axis), turns * std::f32::consts::TAU)
+            };
+            out.push(Draw {
+                image: (first + i) as u16,
+                blend: blend(layer.blend),
+                brightness,
+                rotation,
+            });
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::custom_sky::{Conditions, Weather};
+
+    fn pack(files: &[(&str, &str)]) -> (std::path::PathBuf, CustomSky) {
+        let root = std::env::temp_dir().join(format!(
+            "horizon-custom-sky-{}-{}",
+            std::process::id(),
+            files.len()
+        ));
+        let _ = std::fs::remove_dir_all(&root);
+        let dir = root.join("assets/minecraft/optifine/sky/world0");
+        std::fs::create_dir_all(&dir).unwrap();
+        let png = {
+            let mut bytes = Vec::new();
+            let mut encoder = png::Encoder::new(&mut bytes, 6, 4);
+            encoder.set_color(png::ColorType::Rgba);
+            encoder.set_depth(png::BitDepth::Eight);
+            let mut writer = encoder.write_header().unwrap();
+            writer
+                .write_image_data(&[255, 0, 0, 255].repeat(24))
+                .unwrap();
+            writer.finish().unwrap();
+            bytes
+        };
+        for (name, text) in files {
+            std::fs::write(dir.join(format!("{name}.properties")), text).unwrap();
+            std::fs::write(dir.join(format!("{name}.png")), &png).unwrap();
+        }
+        let sky = CustomSky::load(&root);
+        (root, sky)
+    }
+
+    fn noon(biome: &str) -> Conditions<'_> {
+        Conditions {
+            day_time: 6000,
+            weather: Weather::Clear,
+            biome,
+            y: 64,
+        }
+    }
+
+    #[test]
+    fn layers_ease_in_at_a_biome_border_but_not_on_arrival() {
+        let (root, sky) = pack(&[
+            ("sky1", "biomes=desert\ntransition=2"),
+            ("sky2", "blend=alpha\nrotate=false"),
+        ]);
+        let _ = std::fs::remove_dir_all(root);
+        assert!(sky.has(0) && !sky.has(1));
+        assert_eq!(sky.images[0].width, 6);
+        let (mut state, mut out) = (State::default(), Vec::new());
+        sky.draws(
+            0,
+            &noon("minecraft:desert"),
+            0.0,
+            0.05,
+            &mut state,
+            &mut out,
+        );
+        assert_eq!(
+            out.iter().map(|d| d.brightness).collect::<Vec<_>>(),
+            [1.0, 1.0]
+        );
+        // Out of the desert: the first layer fades over its two seconds.
+        sky.draws(0, &noon("minecraft:plains"), 0.0, 0.5, &mut state, &mut out);
+        assert_eq!(out[0].brightness, 0.75);
+        assert_eq!(out[1].blend, engine::Blend::Alpha);
+        sky.draws(0, &noon("minecraft:plains"), 0.0, 2.0, &mut state, &mut out);
+        assert_eq!(out.len(), 1, "a dark layer is not drawn");
+        assert_eq!(out[0].image, 1);
+        // Into the End, which has no layers, and back: no fade.
+        sky.draws(1, &noon("minecraft:desert"), 0.0, 0.0, &mut state, &mut out);
+        assert!(out.is_empty());
+        sky.draws(0, &noon("minecraft:desert"), 0.0, 0.0, &mut state, &mut out);
+        assert_eq!(out.len(), 2);
+    }
+
+    #[test]
+    fn a_layer_turns_west_like_the_sun() {
+        let (root, sky) = pack(&[("sky1", "")]);
+        let _ = std::fs::remove_dir_all(root);
+        let (mut state, mut out) = (State::default(), Vec::new());
+        // A quarter turn after noon (sunset): the skybox's zenith has gone down to the west.
+        let c = Conditions {
+            day_time: 12000,
+            ..noon("minecraft:plains")
+        };
+        sky.draws(0, &c, 0.25, 0.0, &mut state, &mut out);
+        let up = out[0].rotation.transform_vector3(Vec3::Y);
+        assert!((up - Vec3::NEG_X).length() < 1e-5, "{up}");
+    }
+}
@@ -0,0 +1,146 @@
+//! Polytone's item modifiers' durability bar colours, on the engine's
+//! [`crate::pack_palette::ItemBars`].
+use std::path::Path;
+use std::sync::Arc;
+
+/// An item modifier's `bar_color` of the `damage` type: a row of colours picked by the stack's
+/// damage, the first pixel undamaged, the last at full damage (measured on the real mod).
+struct DamageBar {
+    targets: horizon_polytone::Targets,
+    row: Vec<u32>,
+}
+
+/// The packs' damage bars, the last read first.
+struct Bars(Vec<DamageBar>);
+
+impl crate::pack_palette::ItemBars for Bars {
+    fn color(&self, item: &str, damage: f32) -> Option<u32> {
+        let bar = self
+            .0
+            .iter()
+            .rev()
+            .find(|b| b.targets.matches(item, |_| false))?;
+        let last = (bar.row.len() - 1) as f32;
+        Some(bar.row[(damage.clamp(0.0, 1.0) * last).round() as usize])
+    }
+}
+
+/// Reads the packs' item modifiers' durability bar colours under a pack overlay root: an
+/// `<item>_bar.png` alone, or a json whose `bar_color` is `damage` with its `<name>_bar.png` (or
+/// `<name>.png`) beside it. Colormap ids and inline colormaps aren't read. `None` without any.
+pub fn read(root: &Path) -> Option<Arc<dyn crate::pack_palette::ItemBars>> {
+    let mut bars = Vec::new();
+    for namespace in std::fs::read_dir(root.join("assets"))
+        .into_iter()
+        .flatten()
+        .flatten()
+    {
+        let base = namespace.path().join("polytone/item_modifiers");
+        let mut stack = vec![base.clone()];
+        while let Some(dir) = stack.pop() {
+            for entry in std::fs::read_dir(&dir).into_iter().flatten().flatten() {
+                let path = entry.path();
+                if path.is_dir() {
+                    stack.push(path);
+                } else if let Some(bar) = item_bar(root, &base, &path) {
+                    bars.push(bar);
+                }
+            }
+        }
+    }
+    (!bars.is_empty()).then(|| Arc::new(Bars(bars)) as _)
+}
+
+fn item_bar(root: &Path, base: &Path, path: &Path) -> Option<DamageBar> {
+    let name = path.file_name()?.to_str()?;
+    let row = |png: &Path| {
+        let (width, _, rgba) = crate::sprites::read_rgba(png).ok()?;
+        let row: Vec<u32> = rgba[..width as usize * 4]
+            .as_chunks::<4>()
+            .0
+            .iter()
+            .map(|p| u32::from(p[0]) << 16 | u32::from(p[1]) << 8 | u32::from(p[2]))
+            .collect();
+        (!row.is_empty()).then_some(row)
+    };
+    if let Some(stem) = name.strip_suffix("_bar.png") {
+        // A json of the same name owns its png.
+        if path.with_file_name(format!("{stem}.json")).exists() {
+            return None;
+        }
+        let relative = path.parent()?.strip_prefix(base).ok()?.join(stem);
+        let namespace = base.parent()?.parent()?.file_name()?.to_str()?;
+        let id = format!("{namespace}:{}", relative.to_str()?.replace('\\', "/"));
+        let targets = horizon_polytone::Targets::parse(None, Some(&id)).ok()?;
+        return Some(DamageBar {
+            targets,
+            row: row(path)?,
+        });
+    }
+    let stem = name.strip_suffix(".json")?;
+    let json: serde_json::Value = horizon_world::json_file::read(path).ok()?;
+    if json.get("bar_color")?.as_str()? != "damage" {
+        return None;
+    }
+    let png = [format!("{stem}_bar.png"), format!("{stem}.png")]
+        .into_iter()
+        .map(|png| path.with_file_name(png))
+        .find(|png| png.exists())?;
+    let relative = path.strip_prefix(root).unwrap_or(path).to_string_lossy();
+    let implicit = horizon_polytone::implicit_id(&relative, "item_modifiers");
+    let targets =
+        horizon_polytone::Targets::parse(json.get("targets"), implicit.as_deref()).ok()?;
+    Some(DamageBar {
+        targets,
+        row: row(&png)?,
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn png_row(path: &Path, pixels: &[[u8; 3]]) {
+        std::fs::create_dir_all(path.parent().unwrap()).unwrap();
+        let file = std::fs::File::create(path).unwrap();
+        let mut encoder = png::Encoder::new(file, pixels.len() as u32, 1);
+        encoder.set_color(png::ColorType::Rgba);
+        let data: Vec<u8> = pixels
+            .iter()
+            .flat_map(|p| [p[0], p[1], p[2], 255])
+            .collect();
+        encoder
+            .write_header()
+            .unwrap()
+            .write_image_data(&data)
+            .unwrap();
+    }
+
+    #[test]
+    fn a_damage_bar_picks_its_pixel_by_the_stacks_damage() {
+        let dir = std::env::temp_dir().join(format!("pack-bars-{}", std::process::id()));
+        let modifiers = dir.join("assets/minecraft/polytone/item_modifiers");
+        let rgby = [[255, 0, 0], [0, 255, 0], [0, 0, 255], [255, 255, 0]];
+        png_row(&modifiers.join("diamond_pickaxe_bar.png"), &rgby);
+        std::fs::write(
+            modifiers.join("tools.json"),
+            r#"{"targets": ["minecraft:iron_axe"], "bar_color": "damage"}"#,
+        )
+        .unwrap();
+        png_row(&modifiers.join("tools_bar.png"), &[[1, 2, 3], [4, 5, 6]]);
+        let bars = read(&dir).unwrap();
+        // The real mod: damage 200 of 1561 shows the first pixel, 1400 the last.
+        assert_eq!(
+            bars.color("minecraft:diamond_pickaxe", 200.0 / 1561.0),
+            Some(0xFF0000)
+        );
+        assert_eq!(
+            bars.color("minecraft:diamond_pickaxe", 1400.0 / 1561.0),
+            Some(0xFFFF00)
+        );
+        assert_eq!(bars.color("minecraft:iron_axe", 0.9), Some(0x040506));
+        assert_eq!(bars.color("minecraft:diamond_shovel", 0.5), None);
+        assert!(read(&dir.join("none")).is_none());
+        std::fs::remove_dir_all(&dir).ok();
+    }
+}
@@ -0,0 +1,40 @@
+//! The resource pack formats vanilla doesn't read (OptiFine's, Polytone's) on the engine's
+//! extension points ([`crate::pack_hooks`]). This is platform code (docs/layers.md) kept in this
+//! 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.
+
+mod colors;
+mod custom_sky;
+mod item_bars;
+
+use std::path::Path;
+use std::sync::Arc;
+
+use crate::pack_hooks::PackFormats;
+
+/// OptiFine's and Polytone's formats.
+pub struct Formats;
+
+impl PackFormats for Formats {
+    fn colors(&self, root: &Path) -> Option<crate::pack_palette::PackColors> {
+        Some(colors::read(root))
+    }
+
+    fn emissive_suffix(&self, root: &Path) -> Option<String> {
+        Some(horizon_optifine::emissive::suffix(root))
+    }
+
+    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 item_bars(&self, root: &Path) -> Option<Arc<dyn crate::pack_palette::ItemBars>> {
+        item_bars::read(root)
+    }
+}
+
+/// Installs these formats ([`crate::pack_hooks::install`]); the game does at startup.
+pub fn install() {
+    crate::pack_hooks::install(&Formats);
+}
@@ -0,0 +1,51 @@
+//! The engine's extension points for resource pack formats vanilla doesn't read (OptiFine's,
+//! Polytone's: platform code, docs/layers.md). The engine asks [`formats`] once per pack load and
+//! gets engine types back (tables, or an object it calls at most once a frame), never a format's
+//! own types. The platform installs its formats at startup ([`install`]); with none installed,
+//! packs load as vanilla reads them.
+
+use std::path::Path;
+use std::sync::{Arc, OnceLock};
+
+/// What the pack formats beyond vanilla's add to a pack. Each method reads one overlay of a pack
+/// (its folder at `root`); the default is "nothing in this format".
+pub trait PackFormats: Send + Sync {
+    /// The colours the overlay replaces where vanilla hardcodes them.
+    fn colors(&self, _root: &Path) -> Option<crate::pack_palette::PackColors> {
+        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 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 durability bar colours the overlay sets by item, if any.
+    fn item_bars(&self, _root: &Path) -> Option<Arc<dyn crate::pack_palette::ItemBars>> {
+        None
+    }
+}
+
+/// No format beyond vanilla's.
+struct Vanilla;
+
+impl PackFormats for Vanilla {}
+
+static FORMATS: OnceLock<&'static dyn PackFormats> = OnceLock::new();
+
+/// Installs the pack formats, before the first pack loads. The first call wins: later ones are
+/// ignored, so each test or probe that needs the formats may install them.
+pub fn install(formats: &'static dyn PackFormats) {
+    let _ = FORMATS.set(formats);
+}
+
+/// The installed pack formats, or vanilla's alone.
+pub fn formats() -> &'static dyn PackFormats {
+    FORMATS.get().copied().unwrap_or(&Vanilla)
+}
@@ -1,14 +1,106 @@
-//! Polytone's dye, sheep and redstone colours (`dye.<name>.diffuse|text`, `sheep.<name>`,
-//! `redstone.<power>`), for drawing only: the pack recolours collars, tropical fish, banners, wool,
-//! sign text and redstone wire and dust, while gameplay (crafting, item data, the beacon) keeps
-//! vanilla's `DyeColor`. Lock-free: the draw paths and the mesher's workers read it per face.
+//! The colours a pack replaces where vanilla hardcodes them (Polytone's `colors.json`, read by the
+//! platform's pack formats, [`crate::pack_hooks`]): dye, sheep and redstone colours, for drawing
+//! only (the pack recolours collars, tropical fish, banners, wool, sign text and redstone wire and
+//! dust, while gameplay keeps vanilla's `DyeColor`), mob effect colours, the experience number's,
+//! entity shadows, the effect fogs' settings and durability bar colours. Lock-free: the draw paths
+//! and the mesher's workers read the dye, sheep and redstone tables per face.
 use std::path::Path;
-use std::sync::RwLock;
 use std::sync::atomic::{AtomicU64, Ordering::Relaxed};
+use std::sync::{Arc, RwLock};

 use crate::block_entity_render::DYES;
 use crate::signs::DYE_TEXT;
-use horizon_polytone::colors::PackColors;
+
+/// The fog settings vanilla hardcodes, as the packs set them (vanilla's by default).
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub struct Environment {
+    /// The fog colour inside powder snow (RGB).
+    pub powder_snow_fog: Option<u32>,
+    /// The fog ends of Blindness (5), Darkness (15) and bosses that add world fog (96).
+    pub blindness_fog_distance: f32,
+    pub darkness_fog_distance: f32,
+    pub boss_fog_distance: f32,
+    /// How much the underwater fog colour washes out (1 vanilla, 0 none).
+    pub water_fog_brightening: f32,
+    /// The ticks under water it takes (vanilla's 600).
+    pub water_fog_brightening_time: f32,
+    /// Below it the sky draws its dark disc (vanilla's 63; flat worlds keep their floor).
+    pub horizon_height: f32,
+}
+
+impl Default for Environment {
+    fn default() -> Self {
+        Self {
+            powder_snow_fog: None,
+            blindness_fog_distance: 5.0,
+            darkness_fog_distance: 15.0,
+            boss_fog_distance: 96.0,
+            water_fog_brightening: 1.0,
+            water_fog_brightening_time: 600.0,
+            horizon_height: 63.0,
+        }
+    }
+}
+
+/// The packs' colours; `None` (and the defaults) where they keep vanilla's.
+#[derive(Clone, Debug, PartialEq)]
+pub struct PackColors {
+    /// By dye id (`DyeColor` order): `getTextureDiffuseColor`, `getTextColor`, the sheep's wool.
+    pub dye_diffuse: [Option<u32>; 16],
+    pub dye_text: [Option<u32>; 16],
+    pub sheep: [Option<u32>; 16],
+    /// `RedStoneWireBlock.COLORS` by power.
+    pub redstone: [Option<u32>; 16],
+    /// Mob effects' colours, by effect id without vanilla's namespace.
+    pub effects: Vec<(String, u32)>,
+    /// False hides every entity's round shadow, whatever the video option says.
+    pub entity_shadows: bool,
+    /// The experience level number's colour and outline.
+    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 {
+    fn default() -> Self {
+        Self {
+            dye_diffuse: [None; 16],
+            dye_text: [None; 16],
+            sheep: [None; 16],
+            redstone: [None; 16],
+            effects: Vec::new(),
+            entity_shadows: true,
+            xp_bar: [None; 2],
+            env: Environment::default(),
+            fluid_fog: FluidFogs::default(),
+        }
+    }
+}
+
+impl PackColors {
+    /// Whether entities draw their round shadow, as far as the packs say.
+    pub fn entity_shadows(&self) -> bool {
+        self.entity_shadows
+    }
+}

 /// 0 is unset, else `1 << 32 | rgb`.
 static DIFFUSE: [AtomicU64; 16] = [const { AtomicU64::new(0) }; 16];
@@ -16,6 +108,30 @@ static TEXT: [AtomicU64; 16] = [const { AtomicU64::new(0) }; 16];
 static SHEEP: [AtomicU64; 16] = [const { AtomicU64::new(0) }; 16];
 static REDSTONE: [AtomicU64; 16] = [const { AtomicU64::new(0) }; 16];

+/// The colours of the pack overlay at `root`, from the installed pack formats; their dye, sheep
+/// and redstone colours go to the draw paths' tables ([`set`]).
+pub fn read(root: &Path) -> PackColors {
+    let formats = crate::pack_hooks::formats();
+    let colors = formats.colors(root).unwrap_or_default();
+    set(&colors);
+    *ITEM_BARS.write().unwrap_or_else(|e| e.into_inner()) = formats.item_bars(root);
+    colors
+}
+
+/// The packs' durability bar colours by item (Polytone's item modifiers' `bar_color`).
+pub trait ItemBars: Send + Sync {
+    /// The bar colour (RGB) of `item` at this damage (0 to 1), when a pack sets one.
+    fn color(&self, item: &str, damage: f32) -> Option<u32>;
+}
+
+static ITEM_BARS: RwLock<Option<Arc<dyn ItemBars>>> = RwLock::new(None);
+
+/// A pack's durability bar colour (RGB) for an item at this damage (0 to 1).
+pub fn item_bar_color(item: &str, damage: f32) -> Option<u32> {
+    let bars = ITEM_BARS.read().unwrap_or_else(|e| e.into_inner());
+    bars.as_ref()?.color(item, damage)
+}
+
 /// Takes the colours of the packs just loaded (vanilla's where they set none).
 pub fn set(colors: &PackColors) {
    let store = |table: &[AtomicU64; 16], i: usize, color: Option<u32>| {
@@ -24,129 +140,39 @@ pub fn set(colors: &PackColors) {
            Relaxed,
        );
    };
-    for (i, (name, _)) in DYES.iter().enumerate() {
-        store(&DIFFUSE, i, colors.dye(name, "diffuse"));
-        store(&TEXT, i, colors.dye(name, "text"));
-        store(&SHEEP, i, colors.sheep(name));
-        store(&REDSTONE, i, colors.redstone(i as u8));
+    for i in 0..16 {
+        store(&DIFFUSE, i, colors.dye_diffuse[i]);
+        store(&TEXT, i, colors.dye_text[i]);
+        store(&SHEEP, i, colors.sheep[i]);
+        store(&REDSTONE, i, colors.redstone[i]);
    }
 }

-/// An item modifier's `bar_color` of the `damage` type: a row of colours picked by the stack's
-/// damage, the first pixel undamaged, the last at full damage (measured on the real mod).
-struct DamageBar {
-    targets: horizon_polytone::Targets,
-    row: Vec<u32>,
-}
-static ITEM_BARS: RwLock<Vec<DamageBar>> = RwLock::new(Vec::new());
-
-/// Reads the packs' item modifiers' durability bar colours under a pack overlay root: an
-/// `<item>_bar.png` alone, or a json whose `bar_color` is `damage` with its `<name>_bar.png` (or
-/// `<name>.png`) beside it. Colormap ids and inline colormaps aren't read.
-pub fn set_item_bars(root: &Path) {
-    let mut bars = Vec::new();
-    for namespace in std::fs::read_dir(root.join("assets"))
-        .into_iter()
-        .flatten()
-        .flatten()
-    {
-        let base = namespace.path().join("polytone/item_modifiers");
-        let mut stack = vec![base.clone()];
-        while let Some(dir) = stack.pop() {
-            for entry in std::fs::read_dir(&dir).into_iter().flatten().flatten() {
-                let path = entry.path();
-                if path.is_dir() {
-                    stack.push(path);
-                } else if let Some(bar) = item_bar(root, &base, &path) {
-                    bars.push(bar);
-                }
-            }
-        }
-    }
-    *ITEM_BARS.write().unwrap_or_else(|e| e.into_inner()) = bars;
-}
-
-fn item_bar(root: &Path, base: &Path, path: &Path) -> Option<DamageBar> {
-    let name = path.file_name()?.to_str()?;
-    let row = |png: &Path| {
-        let (width, _, rgba) = crate::sprites::read_rgba(png).ok()?;
-        let row: Vec<u32> = rgba[..width as usize * 4]
-            .as_chunks::<4>()
-            .0
-            .iter()
-            .map(|p| u32::from(p[0]) << 16 | u32::from(p[1]) << 8 | u32::from(p[2]))
-            .collect();
-        (!row.is_empty()).then_some(row)
-    };
-    if let Some(stem) = name.strip_suffix("_bar.png") {
-        // A json of the same name owns its png.
-        if path.with_file_name(format!("{stem}.json")).exists() {
-            return None;
-        }
-        let relative = path.parent()?.strip_prefix(base).ok()?.join(stem);
-        let namespace = base.parent()?.parent()?.file_name()?.to_str()?;
-        let id = format!("{namespace}:{}", relative.to_str()?.replace('\\', "/"));
-        let targets = horizon_polytone::Targets::parse(None, Some(&id)).ok()?;
-        return Some(DamageBar {
-            targets,
-            row: row(path)?,
-        });
-    }
-    let stem = name.strip_suffix(".json")?;
-    let json: serde_json::Value = horizon_world::json_file::read(path).ok()?;
-    if json.get("bar_color")?.as_str()? != "damage" {
-        return None;
-    }
-    let png = [format!("{stem}_bar.png"), format!("{stem}.png")]
-        .into_iter()
-        .map(|png| path.with_file_name(png))
-        .find(|png| png.exists())?;
-    let relative = path.strip_prefix(root).unwrap_or(path).to_string_lossy();
-    let implicit = horizon_polytone::implicit_id(&relative, "item_modifiers");
-    let targets =
-        horizon_polytone::Targets::parse(json.get("targets"), implicit.as_deref()).ok()?;
-    Some(DamageBar {
-        targets,
-        row: row(&png)?,
-    })
-}
-
-/// A pack's durability bar colour (RGB) for an item at this damage (0 to 1).
-pub fn item_bar_color(item: &str, damage: f32) -> Option<u32> {
-    let bars = ITEM_BARS.read().unwrap_or_else(|e| e.into_inner());
-    let bar = bars
-        .iter()
-        .rev()
-        .find(|b| b.targets.matches(item, |_| false))?;
-    let last = (bar.row.len() - 1) as f32;
-    Some(bar.row[(damage.clamp(0.0, 1.0) * last).round() as usize])
-}
-
-fn read(table: &[AtomicU64; 16], i: usize) -> Option<u32> {
+fn get(table: &[AtomicU64; 16], i: usize) -> Option<u32> {
    let v = table[i & 15].load(Relaxed);
    (v != 0).then_some(v as u32)
 }

 /// `DyeColor.getTextureDiffuseColor` (RGB) as the packs draw it.
 pub fn diffuse(dye: usize) -> u32 {
-    read(&DIFFUSE, dye).unwrap_or(DYES[dye & 15].1)
+    get(&DIFFUSE, dye).unwrap_or(DYES[dye & 15].1)
 }

 /// `DyeColor.getTextColor` (RGB) as the packs draw it.
 pub fn text(dye: usize) -> u32 {
-    read(&TEXT, dye).unwrap_or(DYE_TEXT[dye & 15].1)
+    get(&TEXT, dye).unwrap_or(DYE_TEXT[dye & 15].1)
 }

 /// A pack's `RedStoneWireBlock.COLORS` entry for this power (RGB), when it sets one.
 pub fn redstone(power: u8) -> Option<u32> {
-    read(&REDSTONE, usize::from(power))
+    get(&REDSTONE, usize::from(power))
 }

 /// `ColorLerper.Type.SHEEP` wool colour: a pack's `sheep.<name>`, else white 0xE6E6E6 and the
 /// others 75% of vanilla's dye (a pack's `dye.*.diffuse` doesn't reach wool).
 pub fn sheep_wool(dye: u8) -> u32 {
    let i = usize::from(dye & 15);
-    if let Some(color) = read(&SHEEP, i) {
+    if let Some(color) = get(&SHEEP, i) {
        return color;
    }
    if i == 0 {
@@ -156,81 +182,3 @@ pub fn sheep_wool(dye: u8) -> u32 {
    let f = |c: u32| ((c as f32 * 0.75).floor() as u32).min(255);
    f(src >> 16 & 255) << 16 | f(src >> 8 & 255) << 8 | f(src & 255)
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn a_pack_recolours_only_what_it_names() {
-        // Dyes no other test draws: the table is process-wide.
-        let dir = std::env::temp_dir().join(format!("pack-dyes-{}", std::process::id()));
-        let polytone = dir.join("assets/obs/polytone");
-        std::fs::create_dir_all(&polytone).unwrap();
-        std::fs::write(
-            polytone.join("colors.json"),
-            r#"{"dye": {"cyan": {"diffuse": "00ff00", "text": "0000ff"}}, "sheep": {"pink": "2040ff"}, "redstone": {"7": "0x123456"}}"#,
-        )
-        .unwrap();
-        set(&PackColors::read(&dir));
-        let (cyan, pink, purple) = (9, 6, 10);
-        assert_eq!(diffuse(cyan), 0x00ff00);
-        assert_eq!(text(cyan), 0x0000ff);
-        assert_eq!(sheep_wool(pink as u8), 0x2040ff);
-        // Wool reads vanilla's dye, not the pack's diffuse: 75% of 0x169C9C.
-        assert_eq!(sheep_wool(cyan as u8), 0x107575);
-        assert_eq!(diffuse(purple), 0x8932B8);
-        assert_eq!(text(purple), 0xA020F0);
-        assert_eq!((redstone(7), redstone(15)), (Some(0x123456), None));
-        set(&PackColors::default());
-        assert_eq!(redstone(7), None);
-        assert_eq!(diffuse(cyan), 0x169C9C);
-        assert_eq!(sheep_wool(pink as u8), 0xB6687F);
-        std::fs::remove_dir_all(&dir).ok();
-    }
-
-    fn png_row(path: &Path, pixels: &[[u8; 3]]) {
-        std::fs::create_dir_all(path.parent().unwrap()).unwrap();
-        let file = std::fs::File::create(path).unwrap();
-        let mut encoder = png::Encoder::new(file, pixels.len() as u32, 1);
-        encoder.set_color(png::ColorType::Rgba);
-        let data: Vec<u8> = pixels
-            .iter()
-            .flat_map(|p| [p[0], p[1], p[2], 255])
-            .collect();
-        encoder
-            .write_header()
-            .unwrap()
-            .write_image_data(&data)
-            .unwrap();
-    }
-
-    #[test]
-    fn a_damage_bar_picks_its_pixel_by_the_stacks_damage() {
-        let dir = std::env::temp_dir().join(format!("pack-bars-{}", std::process::id()));
-        let modifiers = dir.join("assets/minecraft/polytone/item_modifiers");
-        let rgby = [[255, 0, 0], [0, 255, 0], [0, 0, 255], [255, 255, 0]];
-        png_row(&modifiers.join("diamond_pickaxe_bar.png"), &rgby);
-        std::fs::write(
-            modifiers.join("tools.json"),
-            r#"{"targets": ["minecraft:iron_axe"], "bar_color": "damage"}"#,
-        )
-        .unwrap();
-        png_row(&modifiers.join("tools_bar.png"), &[[1, 2, 3], [4, 5, 6]]);
-        set_item_bars(&dir);
-        // The real mod: damage 200 of 1561 shows the first pixel, 1400 the last.
-        assert_eq!(
-            item_bar_color("minecraft:diamond_pickaxe", 200.0 / 1561.0),
-            Some(0xFF0000)
-        );
-        assert_eq!(
-            item_bar_color("minecraft:diamond_pickaxe", 1400.0 / 1561.0),
-            Some(0xFFFF00)
-        );
-        assert_eq!(item_bar_color("minecraft:iron_axe", 0.9), Some(0x040506));
-        assert_eq!(item_bar_color("minecraft:diamond_shovel", 0.5), None);
-        set_item_bars(&dir.join("none"));
-        assert_eq!(item_bar_color("minecraft:diamond_pickaxe", 0.5), None);
-        std::fs::remove_dir_all(&dir).ok();
-    }
-}
@@ -31,6 +31,7 @@ mod native;
 pub mod polytone;
 mod polytone_gpu;
 mod polytone_model;
+mod spawn;
 pub use native::{ParticleController, ParticleUpdate};

 /// `ParticleOptions` with the parameters of the option classes used here.
@@ -1222,8 +1223,9 @@ pub struct ParticleLevel<'a> {
    pub collision: &'a BlockCollisionRegistry<'a>,
    /// Local player feet position and vertical velocity (`PlayerCloudParticle`).
    pub player: Option<([f64; 3], f64)>,
+    pub cached_chunk: std::cell::Cell<Option<((i32, i32), Option<&'a crate::chunk::Chunk>)>>,
 }
-impl ParticleLevel<'_> {
+impl<'a> ParticleLevel<'a> {
    fn collide(&self, bb: Aabb, d: [f64; 3]) -> [f64; 3] {
        let mut scene = SceneCollisions {
            world: self.world,
@@ -1231,9 +1233,6 @@ impl ParticleLevel<'_> {
            subject: None,
        };
        let movement = Vec3::new(d[0], d[1], d[2]);
-        // `Entity.collideBoundingBox(null, ...)`: no entity shapes, no border. Where no
-        // block of the swept box's cells can collide, it finds no shape and the
-        // movement stands, as the resolution below would return it.
        if scene.cells_without_collision(bb.expand_towards(movement)) {
            return d;
        }
@@ -1249,38 +1248,46 @@ impl ParticleLevel<'_> {
            p[2].floor() as i32,
        ]
    }
+    #[inline]
+    pub fn block(&self, x: i32, y: i32, z: i32) -> horizon_world::registry::BlockStateId {
+        let (cx, cz) = (x >> 4, z >> 4);
+        let chunk = match self.cached_chunk.get() {
+            Some(((ccx, ccz), c)) if ccx == cx && ccz == cz => c,
+            _ => {
+                let c = self.world.chunks.get(&(cx, cz)).map(|c| c.as_ref());
+                self.cached_chunk.set(Some(((cx, cz), c)));
+                c
+            }
+        };
+        chunk.map_or(self.world.air, |c| c.block(x & 15, y, z & 15))
+    }
    /// The fluid at a block and `FluidState.getHeight`.
    fn fluid(&self, b: [i32; 3]) -> (Fluid, f64) {
-        let s = self.facts.get(self.world.block(b[0], b[1], b[2]));
+        let s = self.facts.get(self.block(b[0], b[1], b[2]));
        if s.fluid == Fluid::None {
            return (Fluid::None, 0.0);
        }
-        let above = self.facts.get(self.world.block(b[0], b[1] + 1, b[2]));
-        let height = if above.fluid == s.fluid {
+        let above = self.facts.get(self.block(b[0], b[1] + 1, b[2]));
+        let h = if above.fluid == s.fluid {
            1.0
        } else {
            f64::from(s.fluid_level) / 9.0
        };
-        (s.fluid, height)
+        (s.fluid, h)
    }
    /// The fluid at a block and whether it is a source (`FluidState.isSource`).
    pub(crate) fn fluid_source(&self, b: [i32; 3]) -> (Fluid, bool) {
-        let s = self.facts.get(self.world.block(b[0], b[1], b[2]));
+        let s = self.facts.get(self.block(b[0], b[1], b[2]));
        (s.fluid, s.fluid_level == 8 && !s.fluid_falling)
    }
    /// `getCollisionShape(...).max(Y, x, z)` for cached shapes.
    fn collision_top(&self, b: [i32; 3], fx: f64, fz: f64) -> f64 {
-        let state = self.world.block(b[0], b[1], b[2]);
+        let state = self.block(b[0], b[1], b[2]);
        match self.collision.cached_shapes().cached_shape(state) {
            Ok(Some(shape)) if !shape.is_empty() => shape.max_at(Axis::Y, fx, fz),
            Ok(Some(_)) => 0.0,
-            _ => {
-                if self.facts.get(state).full_collision {
-                    1.0
-                } else {
-                    0.0
-                }
-            }
+            _ if self.facts.get(state).full_collision => 1.0,
+            _ => 0.0,
        }
    }
 }
@@ -2020,73 +2027,6 @@ impl ParticleEngine {
            (eye[0] - pos[0]).powi(2) + (eye[1] - pos[1]).powi(2) + (eye[2] - pos[2]).powi(2) <= 9.0
        })
    }
-    /// `ClientPacketListener.handleParticleEvent` for `ServerLevel.sendParticles`.
-    pub fn send_particles(
-        &mut self,
-        options: &ParticleOptions,
-        at: [f64; 3],
-        spread: [f64; 3],
-        speed: f64,
-        count: u32,
-    ) {
-        if count == 0 {
-            let v = [speed * spread[0], speed * spread[1], speed * spread[2]];
-            self.add(options, at, v);
-            return;
-        }
-        for _ in 0..count {
-            let r = &mut self.random;
-            let p = [
-                at[0] + r.next_gaussian() * spread[0],
-                at[1] + r.next_gaussian() * spread[1],
-                at[2] + r.next_gaussian() * spread[2],
-            ];
-            let v = [
-                r.next_gaussian() * speed,
-                r.next_gaussian() * speed,
-                r.next_gaussian() * speed,
-            ];
-            self.add(options, p, v);
-        }
-    }
-    /// `ParticleEngine.createParticle`: always spawned, but `ParticleEngine.add`
-    /// drops a spore blossom air particle once `ParticleLimit.SPORE_BLOSSOM` is full.
-    pub fn create(&mut self, options: &ParticleOptions, p: [f64; 3], v: [f64; 3]) {
-        if let Some(requests) = &mut self.created_requests {
-            requests.push((options.clone(), p, v));
-            return;
-        }
-        let seed = self.seeds.next_long();
-        if let Some(mut particle) = self.make(options, p, v, seed) {
-            *self.made.entry(options.ty.name()).or_default() += 1;
-            // Resource packs' Polytone particle modifiers (#11486), once as it spawns.
-            if let Some(registry) = &self.polytone
-                && registry.modifies_particles()
-            {
-                let id = match &options.mod_particle {
-                    Some(name) => name.clone(),
-                    None => format!("minecraft:{}", options.ty.name()),
-                };
-                polytone::modify(registry, &id, options.source.as_deref(), &mut particle);
-            }
-            // The provider has drawn, so rejecting here keeps vanilla's RNG order.
-            // shortcut: counts live plus queued particles by scanning instead of
-            // vanilla's counted map; use a counter if spore spawning shows in profiles.
-            if particle.ty == ParticleType::SporeBlossomAir
-                && self.particles.len() + self.pending.len() >= SPORE_BLOSSOM_LIMIT
-                && self
-                    .particles
-                    .iter()
-                    .chain(self.pending.iter())
-                    .filter(|q| q.ty == ParticleType::SporeBlossomAir)
-                    .count()
-                    >= SPORE_BLOSSOM_LIMIT
-            {
-                return;
-            }
-            self.pending.push(particle);
-        }
-    }
    /// How many particles of each type were made so far.
    pub fn made(&self) -> &std::collections::BTreeMap<&'static str, u64> {
        &self.made
@@ -4052,15 +3992,12 @@ impl ParticleEngine {
            }
            Behaviour::Lava => {
                p.base_tick(level);
-                if !p.removed {
-                    let odds = p.age as f32 / p.lifetime as f32;
-                    if p.random.next_float() > odds {
-                        self.add(
-                            &ParticleOptions::simple(ParticleType::Smoke),
-                            p.position,
-                            p.velocity,
-                        );
-                    }
+                if !p.removed && p.random.next_float() > p.age as f32 / p.lifetime as f32 {
+                    self.add(
+                        &ParticleOptions::simple(ParticleType::Smoke),
+                        p.position,
+                        p.velocity,
+                    );
                }
            }
            Behaviour::Crit => {
@@ -4144,9 +4081,7 @@ impl ParticleEngine {
                    *c *= f64::from(0.98f32);
                }
                if p.on_ground {
-                    if p.random.next_float() < 0.5 {
-                        p.removed = true;
-                    }
+                    p.removed |= p.random.next_float() < 0.5;
                    p.velocity[0] *= f64::from(0.7f32);
                    p.velocity[2] *= f64::from(0.7f32);
                }
@@ -4186,13 +4121,10 @@ impl ParticleEngine {
            } => {
                p.base_tick(level);
                let (fluid, source) = level.fluid_source(ParticleLevel::block_at(p.position));
-                if !(p.removed || (fluid == Fluid::Water && source)) {
-                    p.removed = true;
-                }
-                if !p.removed && p.position[1] >= y_end {
-                    p.removed = true;
-                }
-                if !p.removed && p.position[1] <= y_prev {
+                if !(fluid == Fluid::Water && source)
+                    || p.position[1] >= y_end
+                    || p.position[1] <= y_prev
+                {
                    p.removed = true;
                }
                // randomHorizontalWiggling, then a second, horizontal move.
@@ -4216,9 +4148,8 @@ impl ParticleEngine {
                p.base_tick(level);
                self.sprite_from_age(p);
                if p.age as f32 > fade_start {
-                    let frames_since_fade_out_start = p.age as f32 - fade_start;
                    p.rgba[3] =
-                        (p.lifetime as f32 - frames_since_fade_out_start) / p.lifetime as f32;
+                        (p.lifetime as f32 - (p.age as f32 - fade_start)) / p.lifetime as f32;
                }
            }
            Behaviour::NoxiousGasCloud => {
@@ -4682,7 +4613,7 @@ impl ParticleEngine {
                    self.sprite_from_age(p);
                    half(p);
                    let b = ParticleLevel::block_at(p.position);
-                    if level.facts.is_air(level.world.block(b[0], b[1], b[2])) {
+                    if level.facts.is_air(level.block(b[0], b[1], b[2])) {
                        p.velocity[1] -= f64::from(0.0074f32);
                    }
                }
@@ -4690,7 +4621,7 @@ impl ParticleEngine {
            Behaviour::Firefly => {
                p.base_tick(level);
                let b = ParticleLevel::block_at(p.position);
-                if !level.facts.is_air(level.world.block(b[0], b[1], b[2])) {
+                if !level.facts.is_air(level.block(b[0], b[1], b[2])) {
                    p.removed = true;
                } else {
                    p.rgba[3] = fade_amount(p.lifetime_progress(p.age as f32), 0.3, 0.5);
@@ -5154,11 +5085,12 @@ fn hdr_tier(ty: ParticleType) -> u8 {
 }
 /// `Particle.LifetimeAlpha.currentAlphaForAge`.
 fn lifetime_alpha(a: [f32; 4], age: i32, lifetime: i32, partial: f32) -> f32 {
-    if (a[0] - a[1]).abs() < 1.0e-5 {
-        return a[0];
-    }
    let t = ((age as f32 + partial) / lifetime as f32 - a[2]) / (a[3] - a[2]);
-    a[0] + (a[1] - a[0]) * t.clamp(0.0, 1.0)
+    if (a[0] - a[1]).abs() < 1.0e-5 {
+        a[0]
+    } else {
+        a[0] + (a[1] - a[0]) * t.clamp(0.0, 1.0)
+    }
 }

 struct Starter {
@@ -5589,6 +5521,7 @@ mod tests {
            facts: &facts,
            collision: &collision,
            player: None,
+            cached_chunk: std::cell::Cell::new(None),
        };
        let mut engine = ParticleEngine::new(Path::new(""), &HashMap::new(), &HashSet::new());
        engine.set_sprites.push(vec![10, 11, 12]);
@@ -5680,6 +5613,7 @@ mod tests {
            facts: &facts,
            collision: &collision,
            player: None,
+            cached_chunk: std::cell::Cell::new(None),
        };
        let mut engine = ParticleEngine::new(Path::new(""), &HashMap::new(), &HashSet::new());
        let mut particle = Particle::blank(ParticleType::Smoke, [0.0; 3]);
@@ -124,6 +124,7 @@ mod tests {
            facts: &facts,
            collision: &collision,
            player: None,
+            cached_chunk: std::cell::Cell::new(None),
        };
        let mut e = engine();
        let mut p = e
@@ -490,14 +490,14 @@ enum Subject<'a> {
 }

 /// What one expression runs against: its subject, the frame and the level.
-struct Ctx<'a> {
+struct Ctx<'a, 'l> {
    subject: Subject<'a>,
    random: &'a mut LegacyRandom,
    custom: &'a mut f64,
    customs: &'a mut BTreeMap<String, f64>,
    frame: &'a Frame,
    registry: &'a Registry,
-    level: Option<&'a ParticleLevel<'a>>,
+    level: Option<&'a ParticleLevel<'l>>,
    blocks: Vec<[i32; 3]>,
 }

@@ -515,7 +515,7 @@ fn axis(name: &str) -> usize {
    usize::from(name.as_bytes()[0] - b'x')
 }

-impl Ctx<'_> {
+impl Ctx<'_, '_> {
    fn position(&self) -> [f64; 3] {
        match &self.subject {
            Subject::Particle(p) => p.position,
@@ -683,7 +683,7 @@ impl Ctx<'_> {
    }
 }

-impl Host for Ctx<'_> {
+impl Host for Ctx<'_, '_> {
    fn root(&mut self, root: Root) -> V {
        match root {
            Root::Object => V::Object(SELF),
@@ -801,6 +801,26 @@ impl Host for Ctx<'_> {
            _ => 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> {
@@ -1662,6 +1682,7 @@ mod tests {
            facts: &scene.facts,
            collision: &scene.collision,
            player: None,
+            cached_chunk: std::cell::Cell::new(None),
        };
        let mut engine = engine(Registry::read(&root, Default::default(), blocks));
        // Air has no emitters; the torch fires its first emitter only.
@@ -1701,6 +1722,7 @@ mod tests {
            facts: &scene.facts,
            collision: &scene.collision,
            player: None,
+            cached_chunk: std::cell::Cell::new(None),
        };
        let mut engine = engine(Registry::read(&root, Default::default(), blocks));
        engine.polytone_animate(&level, [1, 64, 1]);
@@ -1722,6 +1744,7 @@ mod tests {
            facts: &scene.facts,
            collision: &scene.collision,
            player: None,
+            cached_chunk: std::cell::Cell::new(None),
        };
        let mut engine = engine(Registry::read(&root, Default::default(), blocks));
        engine.polytone_animate(&level, [1, 64, 1]);
@@ -1767,6 +1790,7 @@ mod tests {
            facts: &scene.facts,
            collision: &scene.collision,
            player: None,
+            cached_chunk: std::cell::Cell::new(None),
        };
        let registry = Registry::read(&root, Default::default(), blocks);
        let frame = registry.frame.clone();
@@ -1820,6 +1844,7 @@ mod tests {
            facts: &scene.facts,
            collision: &scene.collision,
            player: None,
+            cached_chunk: std::cell::Cell::new(None),
        };
        let registry = Registry::read(&root, Default::default(), blocks);
        let mut engine = engine(registry);
@@ -1853,6 +1878,7 @@ mod tests {
            facts: &scene.facts,
            collision: &scene.collision,
            player: None,
+            cached_chunk: std::cell::Cell::new(None),
        };
        let mut engine = engine(Registry::read(&root, Default::default(), blocks));
        let rect = crate::hud::Rect {
@@ -1905,6 +1931,7 @@ mod tests {
            facts: &scene.facts,
            collision: &scene.collision,
            player: None,
+            cached_chunk: std::cell::Cell::new(None),
        };
        let mut engine = engine(Registry::read(&root, Default::default(), blocks));
        let rect = crate::hud::Rect {
@@ -1966,6 +1993,7 @@ mod tests {
            facts: &scene.facts,
            collision: &scene.collision,
            player: None,
+            cached_chunk: std::cell::Cell::new(None),
        };
        let mut engine = engine(Registry::read(&root, Default::default(), blocks));
        engine.polytone_entity(&level, "minecraft:player", [1.0, 70.0, 1.0]);
@@ -2014,6 +2042,7 @@ mod tests {
            facts: &scene.facts,
            collision: &scene.collision,
            player: None,
+            cached_chunk: std::cell::Cell::new(None),
        };
        let mut engine = engine(Registry::read(&root, Default::default(), blocks));
        let rect = crate::hud::Rect {
@@ -2080,6 +2109,7 @@ mod tests {
            facts: &scene.facts,
            collision: &scene.collision,
            player: None,
+            cached_chunk: std::cell::Cell::new(None),
        };
        let registry = Arc::new(Registry::read(&root, Default::default(), blocks));
        // The chunk's biome is id 0: plains, whose foliage is #336699.
@@ -2198,6 +2228,7 @@ mod tests {
            facts: &scene.facts,
            collision: &scene.collision,
            player: None,
+            cached_chunk: std::cell::Cell::new(None),
        };
        let mut engine = engine(Registry::read(&root, Default::default(), blocks));
        engine.polytone_entity(&level, "minecraft:player", [1.5, 70.0, 1.5]);
@@ -2276,6 +2307,7 @@ mod tests {
            facts: &scene.facts,
            collision: &scene.collision,
            player: None,
+            cached_chunk: std::cell::Cell::new(None),
        };
        let mut engine = engine(Registry::read(&root, Default::default(), blocks));
        // The test chunk's biome is the table's first: a cold one first, then a warm one.
@@ -0,0 +1,73 @@
+//! Where particles come into the engine: a server's particle packet and a single particle made
+//! where the game asks for one.
+use super::*;
+
+impl ParticleEngine {
+    /// `ClientPacketListener.handleParticleEvent` for `ServerLevel.sendParticles`.
+    pub fn send_particles(
+        &mut self,
+        options: &ParticleOptions,
+        at: [f64; 3],
+        spread: [f64; 3],
+        speed: f64,
+        count: u32,
+    ) {
+        if count == 0 {
+            let v = [speed * spread[0], speed * spread[1], speed * spread[2]];
+            self.add(options, at, v);
+            return;
+        }
+        for _ in 0..count {
+            let r = &mut self.random;
+            let p = [
+                at[0] + r.next_gaussian() * spread[0],
+                at[1] + r.next_gaussian() * spread[1],
+                at[2] + r.next_gaussian() * spread[2],
+            ];
+            let v = [
+                r.next_gaussian() * speed,
+                r.next_gaussian() * speed,
+                r.next_gaussian() * speed,
+            ];
+            self.add(options, p, v);
+        }
+    }
+    /// `ParticleEngine.createParticle`: always spawned, but `ParticleEngine.add`
+    /// drops a spore blossom air particle once `ParticleLimit.SPORE_BLOSSOM` is full.
+    pub fn create(&mut self, options: &ParticleOptions, p: [f64; 3], v: [f64; 3]) {
+        if let Some(requests) = &mut self.created_requests {
+            requests.push((options.clone(), p, v));
+            return;
+        }
+        let seed = self.seeds.next_long();
+        if let Some(mut particle) = self.make(options, p, v, seed) {
+            *self.made.entry(options.ty.name()).or_default() += 1;
+            // Resource packs' Polytone particle modifiers (#11486), once as it spawns.
+            if let Some(registry) = &self.polytone
+                && registry.modifies_particles()
+            {
+                let id = match &options.mod_particle {
+                    Some(name) => name.clone(),
+                    None => format!("minecraft:{}", options.ty.name()),
+                };
+                polytone::modify(registry, &id, options.source.as_deref(), &mut particle);
+            }
+            // The provider has drawn, so rejecting here keeps vanilla's RNG order.
+            // shortcut: counts live plus queued particles by scanning instead of
+            // vanilla's counted map; use a counter if spore spawning shows in profiles.
+            if particle.ty == ParticleType::SporeBlossomAir
+                && self.particles.len() + self.pending.len() >= SPORE_BLOSSOM_LIMIT
+                && self
+                    .particles
+                    .iter()
+                    .chain(self.pending.iter())
+                    .filter(|q| q.ty == ParticleType::SporeBlossomAir)
+                    .count()
+                    >= SPORE_BLOSSOM_LIMIT
+            {
+                return;
+            }
+            self.pending.push(particle);
+        }
+    }
+}
@@ -93,6 +93,7 @@ fn particle_tick_cost() {
        facts: &facts,
        collision: &collision,
        player: None,
+        cached_chunk: std::cell::Cell::new(None),
    };
    let ty = |name: &str| ParticleType::from_name(name).unwrap();
    let (fx, fy, fz) = (0.5, f64::from(FLOOR_Y + 5), 20.5);
@@ -4,7 +4,6 @@
 //! Horizon Settings > PvP & HUD. Every option is off by default, so the game looks like
 //! vanilla until the player changes one, and none of them shows anything vanilla doesn't
 //! already tell the player.
-use horizon_hooks::look::Look;

 /// Colours the PvP options pick from. `Inverted` is vanilla's crosshair blend: the colour
 /// under it, inverted.
@@ -264,6 +263,15 @@ impl ViewWeather {
        Self::ALL.into_iter().find(|c| c.name() == s)
    }
 }
+/// The day time this player sees with `fixed` set: the same day (the moon's phase follows the
+/// world's), at that time.
+pub fn view_day_time(world: i64, fixed: Option<ViewTime>) -> i64 {
+    match fixed {
+        Some(t) => world.div_euclid(24000) * 24000 + t.day_time(),
+        None => world,
+    }
+}
+
 /// The crosshair's look. Its defaults draw vanilla's: a 15-pixel cross, one pixel thick,
 /// inverting what is under it.
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
@@ -520,36 +528,24 @@ impl Hit {
    }
 }

+/// What the renderer reads of these options each frame (`FrameInputs::pvp`); the default is
+/// vanilla's look.
+#[derive(Clone, Copy, Debug, Default, PartialEq)]
+pub struct Frame {
+    /// The block outline's stroke ([`Outline::stroke`]).
+    pub outline: Option<(u32, f32)>,
+    /// The hurt overlay texel ([`Hit::texel`]), 0 for vanilla's.
+    pub hurt_texel: u32,
+    /// The glint's colour ([`Tweaks::glint_texel`]), 0 for vanilla's.
+    pub glint: u32,
+}
 impl Pvp {
-    /// What the engine reads of these options (`horizon_hooks::look`): all it draws differently.
-    /// Sets PvP & HUD's fields of `look`, the others' stay.
-    pub fn apply(&self, look: &mut Look) {
-        let (c, t) = (self.combat, self.tweaks);
-        look.legacy_pose = c.legacy;
-        look.hide_attack_indicator = c.legacy && !c.indicator;
-        look.mute_attack_sounds = c.legacy && c.sounds;
-        look.hide_attack_particles = c.legacy;
-        look.frame.outline = self.outline.stroke();
-        look.frame.hurt_texel = self.hit.texel();
-        look.frame.glint = t.glint_texel();
-        look.shield_size = t.shield_size;
-        look.totem_scale = f32::from(t.totem_size) / 100.0;
-        look.fire_lower = f32::from(t.fire_lower) / 100.0;
-        look.clear_lava = t.clear_lava;
-        look.clear_water = t.clear_water;
-        look.chat.timestamps = self.chat.timestamps;
-        look.chat.compact = self.chat.compact;
-        look.chat.copy = self.chat.copy;
-        look.chat.search = self.chat.search;
-        look.hide_effect_icons = self.hud.effects;
-        look.time_of_day = t.time.map(ViewTime::day_time);
-        look.weather = t.weather.map(ViewWeather::levels);
-    }
-    /// [`Pvp::apply`] on vanilla's look.
-    pub fn look(&self) -> Look {
-        let mut look = Look::default();
-        self.apply(&mut look);
-        look
+    pub fn frame(&self) -> Frame {
+        Frame {
+            outline: self.outline.stroke(),
+            hurt_texel: self.hit.texel(),
+            glint: self.tweaks.glint_texel(),
+        }
    }
 }

@@ -745,6 +741,15 @@ pub struct ChatOptions {
    /// Ctrl+F in the chat searches the chat's messages.
    pub search: bool,
 }
+impl ChatOptions {
+    /// What `chat::Chat` lays its lines out with.
+    pub fn qol(&self) -> crate::chat::ChatQol {
+        crate::chat::ChatQol {
+            timestamps: self.timestamps,
+            compact: self.compact,
+        }
+    }
+}

 /// Combat feel (`docs/pvp.md`): how fights look. Legacy draws them as 1.8.9 did; what the
 /// game sends to a server never changes, so a vanilla server and its anticheat see 26.3.
@@ -761,6 +766,21 @@ pub struct Combat {
    /// (`horizon_client::legacy_combat`). Never used as a client of a server.
    pub rules: bool,
 }
+impl Combat {
+    /// Whether this client leaves out sound `name` a server sent: under Legacy with its
+    /// sounds, the `entity.player.attack.*` family (strong, weak, crit, sweep, knockback,
+    /// nodamage), which 1.9 brought with the attack cooldown.
+    pub fn mutes_sound(&self, name: &str) -> bool {
+        let name = name.strip_prefix("minecraft:").unwrap_or(name);
+        self.legacy && self.sounds && name.starts_with("entity.player.attack.")
+    }
+    /// Whether this client leaves out particles of `ty` a server sent: under Legacy, the
+    /// sweep and the damage hearts, which 1.9 brought (1.8.9's hits show crits only).
+    pub fn hides_particle(&self, ty: crate::particles::ParticleType) -> bool {
+        use crate::particles::ParticleType as T;
+        self.legacy && matches!(ty, T::SweepAttack | T::DamageIndicator)
+    }
+}

 #[derive(Clone, Debug, PartialEq)]
 pub struct Pvp {
@@ -1687,6 +1707,18 @@ mod tests {
        assert_eq!(fresh.extras.pvp.tweaks.fire_lower, PRESET_FIRE_LOWER);
    }

+    #[test]
+    fn a_fixed_time_keeps_the_worlds_day() {
+        // Day 9 at 5000: the moon's phase (the day number) stays, the time of day is the chosen.
+        let world = 9 * 24000 + 5000;
+        assert_eq!(view_day_time(world, None), world);
+        assert_eq!(
+            view_day_time(world, Some(ViewTime::Midnight)),
+            9 * 24000 + 18000
+        );
+        assert_eq!(view_day_time(-100, Some(ViewTime::Noon)), -24000 + 6000);
+    }
+
    #[test]
    fn the_glint_colour_reaches_the_shaders_as_rgb_bytes() {
        let mut t = Tweaks::default();
@@ -1773,33 +1805,31 @@ mod tests {
        }
    }

-    /// Legacy leaves out what 1.9 added to a hit: its sounds only with the sounds option, the
-    /// sweep and hearts always; the indicator stays when kept. Modern changes nothing.
    #[test]
-    fn combat_feel_reaches_the_look() {
-        let mut pvp = Pvp::default();
-        assert_eq!(pvp.look(), Look::default(), "vanilla's look");
-        let strong = "minecraft:entity.player.attack.strong";
-        pvp.combat.legacy = true;
-        let look = pvp.look();
-        assert!(look.legacy_pose && look.hide_attack_particles && look.hide_attack_indicator);
-        assert!(!look.mutes_sound(strong), "only with the sounds option");
-        pvp.combat.sounds = true;
-        pvp.combat.indicator = true;
-        let look = pvp.look();
-        assert!(look.mutes_sound(strong) && !look.hide_attack_indicator);
-    }
-
-    #[test]
-    fn view_time_weather_and_sizes_reach_the_look() {
-        let mut pvp = Pvp::default();
-        pvp.tweaks.time = Some(ViewTime::Midnight);
-        pvp.tweaks.weather = Some(ViewWeather::Thunder);
-        pvp.tweaks.totem_size = 50;
-        pvp.tweaks.fire_lower = 40;
-        let look = pvp.look();
-        assert_eq!(look.day_time(9 * 24000 + 5000), 9 * 24000 + 18000);
-        assert_eq!(look.weather, Some((1.0, 1.0)));
-        assert_eq!((look.totem_scale, look.fire_lower), (0.5, 0.4));
+    fn legacy_leaves_out_what_1_9_added_to_a_hit() {
+        use crate::particles::ParticleType as T;
+        let modern = Combat::default();
+        let legacy = Combat {
+            legacy: true,
+            ..Combat::default()
+        };
+        let sounds = Combat {
+            sounds: true,
+            ..legacy
+        };
+        for name in [
+            "minecraft:entity.player.attack.strong",
+            "entity.player.attack.sweep",
+            "minecraft:entity.player.attack.nodamage",
+        ] {
+            assert!(sounds.mutes_sound(name), "{name}");
+            assert!(!legacy.mutes_sound(name), "only with the sounds option");
+            assert!(!modern.mutes_sound(name));
+        }
+        // 1.8.9 had the hurt sound: it stays.
+        assert!(!sounds.mutes_sound("minecraft:entity.player.hurt"));
+        assert!(legacy.hides_particle(T::SweepAttack) && legacy.hides_particle(T::DamageIndicator));
+        assert!(!legacy.hides_particle(T::Crit) && !legacy.hides_particle(T::EnchantedHit));
+        assert!(!modern.hides_particle(T::SweepAttack));
    }
 }
@@ -871,6 +871,8 @@ pub enum Opt {
    PadGameplayGuide,
    /// `options.modelPart.*`: one skin layer (index into `options_file::MODEL_PARTS`).
    ModelPart(usize),
+    /// A slider of a page a crate registered (`horizon_hooks::pages`): (page, row).
+    Page(usize, usize),
    /// 3D skin layers: the player's outer layer as extruded slabs.
    SkinLayers3d,
    MainHand,
@@ -192,7 +192,12 @@ impl SignData {
        let side = |t: Option<&Tag>| -> SignText {
            let mut out = SignText::default();
            let Some(t) = t else { return out };
-            if let Some(Tag::List(messages)) = t.get("messages") {
+            if let Some(messages) = t.get("messages") {
+                // `SignText.CODEC` reads a side all or nothing: a messages
+                // field that is not a list leaves the side empty.
+                let Tag::List(messages) = messages else {
+                    return SignText::default();
+                };
                for (i, m) in messages.iter().take(4).enumerate() {
                    out.lines[i] = component_text(m);
                    out.click[i] = click_event(m);
@@ -307,6 +312,27 @@ pub fn editor_sprite(folder: &str, wood: &str) -> String {
 #[cfg(test)]
 mod tests {
    use super::*;
+    /// `SignText.CODEC` reads messages as a list: a string field fails the
+    /// whole side, taking its colour and glow with it.
+    #[test]
+    fn messages_that_are_not_a_list_load_an_empty_side() {
+        let tag = Tag::compound([(
+            "front_text",
+            Tag::compound([
+                ("messages", Tag::String("not a list".into())),
+                ("color", Tag::String("red".into())),
+                ("has_glowing_text", Tag::Byte(1)),
+            ]),
+        )]);
+        let mut decoded = SignData::default();
+        decoded.decode(&tag);
+        assert_eq!(
+            decoded.front,
+            SignText::default(),
+            "a failed message list takes the side's colour and glow with it"
+        );
+    }
+
    #[test]
    fn waxed_and_glowing_text_take_any_number() {
        let tag = Tag::compound([
@@ -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
@@ -1238,6 +1238,9 @@ pub struct EditBox {
    /// Grey completion shown after the text (EditBox.setSuggestion).
    pub suggestion: Option<String>,
    pub text_color: u32,
+    /// `EditBox.setCentered`: the text starts in the middle of the box's
+    /// width, not at its left edge (`BookSignScreen`'s title).
+    pub centered: bool,
    /// `EditBox.textColorUneditable`: the colour of a box `setEditable(false)`
    /// made read-only, which still shows its value and caret.
    pub text_color_uneditable: u32,
@@ -1248,6 +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]>,
@@ -1536,9 +1542,11 @@ impl EditBox {
            focused_at: Instant::now(),
            suggestion: None,
            text_color: rgba(224, 224, 224, 255),
+            centered: false,
            text_color_uneditable: rgba(112, 112, 112, 255),
            editable: true,
            message: String::new(),
+            invert_highlighted_text_color: true,
            frame: None,
        }
    }
@@ -1559,6 +1567,16 @@ impl EditBox {
            self.y
        }
    }
+    /// `EditBox.updateTextPosition`: where the text starts, `(width - text
+    /// width) / 2` in for a centred box (vanilla's `textX`), else at
+    /// `text_x` (4 in from a border).
+    pub fn text_start_x(&self, text_width: f32) -> f32 {
+        if self.centered {
+            self.x + ((self.width - text_width) / 2.0).floor()
+        } else {
+            self.text_x()
+        }
+    }
    pub fn reset_blink(&mut self) {
        self.focused_at = Instant::now();
    }
@@ -1641,8 +1659,13 @@ impl EditBox {
    /// EditBox.findClickedPositionInText: the character boundary under GUI `x`.
    pub fn position_at(&mut self, atlas: &HudAtlas, x: f32) -> usize {
        self.layout(atlas);
-        let room = (x.floor() - self.text_x()).min(self.inner_width());
        let rest: String = self.value.chars().skip(self.display).collect();
+        let shown: String = rest
+            .chars()
+            .take(atlas.font.fit(&rest, self.inner_width()))
+            .collect();
+        let start = self.text_start_x(atlas.font.width_text(&Text::literal(shown.as_str())));
+        let room = (x.floor() - start).min(self.inner_width());
        self.display + atlas.font.fit(&rest, room)
    }
    /// EditBox.onClick: the cursor to the pointer, extending the selection
@@ -1849,7 +1872,12 @@ impl EditBox {
                ),
            }
        };
-        let (tx, ty) = (self.text_x(), self.text_y());
+        let start = if self.centered {
+            self.text_start_x(atlas.font.width_text(&Text::literal(displayed.as_str())))
+        } else {
+            self.text_x()
+        };
+        let (tx, ty) = (start, self.text_y());
        let mut draw_x = tx;
        if !displayed.is_empty() {
            let half = if on_screen {
@@ -1894,7 +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 {
@@ -2604,6 +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,
@@ -2650,4 +2696,19 @@ mod tests {
        assert!(edit.key(winit::keyboard::KeyCode::Backspace, false, false));
        assert_eq!(edit.value, "name");
    }
+
+    /// `EditBox.setCentered` (`BookSignScreen`'s title box): with the flag the
+    /// text starts `(width - text width) / 2` in, which is also where a click
+    /// maps; without it the text starts at the box's left edge.
+    #[test]
+    fn a_centred_box_starts_its_text_in_the_middle() {
+        let mut edit = EditBox::new(10.0, 0.0, 114.0, 9.0);
+        edit.bordered = false;
+        assert_eq!(edit.text_start_x(0.0), 10.0);
+        edit.centered = true;
+        assert_eq!(edit.text_start_x(0.0), 67.0);
+        assert_eq!(edit.text_start_x(18.0), 58.0);
+        // (114 - 5) / 2 = 54.5, rounded down.
+        assert_eq!(edit.text_start_x(5.0), 64.0);
+    }
 }
@@ -119,15 +119,17 @@ 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, Discord 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 = ["discord", "friends"]
+horizon-extras = ["horizon-client-lib/horizon-extras", "horizon-client-render/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"]
-# Play with Friends: sharing a world behind an invite code (game/friends.rs) and joining one.
-friends = ["horizon-client-lib/friends", "dep:horizon-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"]
 # Records the call sites of mob random draws (`mob_ai_probe` traces).
 rng-trace = ["horizon-core/rng-trace", "horizon-client-lib/rng-trace"]
 # Rust's allocations go to the system heap instead of mimalloc, where heap profilers that replace
@@ -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.",
@@ -441,6 +442,7 @@
  "HDR Calibration %s/%s: %s": "HDR Calibration %s/%s: %s",
  "Sets the three below full screen, one test picture at a time.": "Sets the three below full screen, one test picture at a time.",
  "Your display didn't say how bright it gets: calibrate to set it up.": "Your display didn't say how bright it gets: calibrate to set it up.",
+  "Your display's reported peak is often too high: calibrate to set it up.": "Your display's reported peak is often too high: calibrate to set it up.",
  "Already set up for your display. Only calibrate if HDR looks wrong.": "Already set up for your display. Only calibrate if HDR looks wrong.",
  "Puts Peak Brightness and Paper White back to your display's setup.": "Puts Peak Brightness and Paper White back to your display's setup.",
  "Set up for your display. Leave on Auto unless it looks wrong.": "Set up for your display. Leave on Auto unless it looks wrong.",
@@ -97,6 +97,7 @@ pub fn main() -> Result<()> {
        facts: &facts,
        collision: &collision,
        player: None,
+        cached_chunk: std::cell::Cell::new(None),
    };
    let mut engine = ParticleEngine::new(&root, &Default::default(), &Default::default());
    let mut out = BufWriter::new(File::create(&args[2])?);
@@ -194,6 +194,7 @@ pub fn main() -> Result<()> {
            facts: &facts,
            collision: &collision,
            player: None,
+            cached_chunk: std::cell::Cell::new(None),
        };
        let v = |key: &str| -> [f64; 3] {
            std::array::from_fn(|i| case[key][i].as_f64().unwrap_or(0.0))
@@ -612,6 +612,7 @@ fn do_animate_tick(
        facts: ctx.facts,
        collision: ctx.collision,
        player: None,
+        cached_chunk: std::cell::Cell::new(None),
    };
    engine.polytone_animate(&level, pos);
    let facts = ctx.facts.get(state);
@@ -1994,8 +1995,10 @@ pub fn campfire_particles<'a>(
        }
    }
 }
-/// `CampfireBlock.makeParticles` (always visible, overriding the limiter);
-/// `smoking` adds the plain smoke puff at the logs.
+/// `CampfireBlock.makeParticles`: the cosy or signal smoke through
+/// `addAlwaysVisibleParticle(.., true, ..)` (it overrides the limiter but still
+/// rolls the Particles option); `smoking` adds the plain smoke puff at the logs
+/// through `addParticle`, so the limiter can drop it.
 pub fn make_campfire_smoke(
    engine: &mut ParticleEngine,
    pos: [i32; 3],
@@ -2014,7 +2017,13 @@ pub fn make_campfire_smoke(
    } else {
        T::CampfireCosySmoke
    };
-    engine.create(&ParticleOptions::simple(ty), [x, y, z], [0.0, 0.07, 0.0]);
+    engine.add_with(
+        &ParticleOptions::simple(ty),
+        [x, y, z],
+        [0.0, 0.07, 0.0],
+        true,
+        true,
+    );
    if smoking {
        let r = engine.random();
        let dx = r.next_double() / 4.0 * sign(r);
@@ -2024,13 +2033,49 @@ pub fn make_campfire_smoke(
            f64::from(pos[1]) + 0.4,
            f64::from(pos[2]) + 0.5 + dz,
        ];
-        engine.create(&ParticleOptions::simple(T::Smoke), at, [0.0, 0.005, 0.0]);
+        add(engine, T::Smoke, at, [0.0, 0.005, 0.0]);
    }
 }

 #[cfg(test)]
 mod tests {
    use super::*;
+    /// `CampfireBlock.makeParticles` through `ClientLevel.doAddParticle`: the
+    /// cosy smoke overrides the limiter, the plain smoke does not, so it is
+    /// dropped beyond 32 blocks and at Particles: Minimal, and at Decreased
+    /// each puff is dropped when `calculateParticleLevel`'s `nextInt(3)` is 0.
+    #[test]
+    fn doused_campfire_smoke_goes_through_the_particle_limiter() {
+        use horizon_core::random::RandomSource as _;
+        use std::collections::{HashMap, HashSet};
+        let run = |level: u8, camera: [f64; 3]| {
+            let mut engine = ParticleEngine::new(Path::new(""), &HashMap::new(), &HashSet::new());
+            engine.seed_randoms(5, 9, 0);
+            engine.created_requests = Some(Vec::new());
+            engine.particle_level = level;
+            engine.camera = camera;
+            for _ in 0..20 {
+                make_campfire_smoke(&mut engine, [0, 64, 0], false, true);
+            }
+            let made = engine.created_requests.take().unwrap();
+            let count = |ty| made.iter().filter(|(o, ..)| o.ty == ty).count();
+            (count(T::CampfireCosySmoke), count(T::Smoke))
+        };
+        let near = [0.5, 65.0, 0.5];
+        assert_eq!(run(0, near), (20, 20), "All");
+        assert_eq!(run(2, near), (20, 0), "Minimal");
+        assert_eq!(run(0, [100.5, 65.0, 0.5]), (20, 0), "100 blocks away");
+        // Decreased: per puff the cosy smoke's roll, then the plain smoke's.
+        let mut level = LegacyRandom::new(9);
+        let kept = (0..20)
+            .filter(|_| {
+                level.next_int_bound(3).unwrap();
+                level.next_int_bound(3).unwrap() != 0
+            })
+            .count();
+        assert!(0 < kept && kept < 20);
+        assert_eq!(run(1, near), (20, kept), "Decreased");
+    }
    #[test]
    fn classifies_animated_blocks() {
        let none = |_: &str| None;
@@ -19,8 +19,8 @@ pub use horizon_client_render::{
    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_palette, pack_screen,
-    packs, pad_cursor, pad_glyph, par, particles, poi_sections, polytone_colors,
+    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,
@@ -70,7 +70,6 @@ pub mod falling_block;
 pub mod fire_render;
 pub mod first_person;
 pub mod flatgen;
-pub mod friends_screen;
 pub mod furnace;
 pub mod game_mode_switcher;
 pub mod game_rules_screen;
@@ -87,7 +86,6 @@ pub mod item_tooltip;
 pub mod join_seq;
 pub mod lan;
 pub mod landing;
-pub mod last_server;
 pub mod legacy_combat;
 pub mod locator_bar;
 pub mod lod_net;
@@ -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;
@@ -84,7 +84,7 @@ fn slime_at(world: &World, facts: &BlockFacts, position: BlockPos) -> bool {
 mod fluids;
 mod item_fall;
 mod item_no_physics;
-pub use fluids::{fluid_flow, update_entity_fluids, water_clip};
+pub use fluids::{fall_reset_hit, fluid_flow, update_entity_fluids, water_clip};

 #[cfg(test)]
 mod drop_motion_tests {
@@ -45,6 +45,30 @@ pub fn fluid_flow(world: &World, fluids: &FluidResources, pos: [i32; 3]) -> [f64
    let flow = flow_at(&mut scene, state, at).unwrap_or(Vec3::ZERO);
    [flow.x, flow.y, flow.z]
 }
+/// `Entity.move`'s fall-reset ray along a move from `from`, up to 8 blocks:
+/// `ClipContext.Fluid.WATER` (the water's shape) and
+/// `ClipContext.Block.FALLDAMAGE_RESETTING` (a block `tagged` says is a reset
+/// block clips as a full block). Both shapes are queried for every visited
+/// block, the water's first (its first query fixes the shared cached shape);
+/// either one hitting ends the ray.
+pub fn fall_reset_hit(
+    world: &World,
+    fluids: &FluidResources,
+    tagged: impl Fn(BlockPos) -> bool,
+    from: Vec3,
+    moved: Vec3,
+) -> bool {
+    let to = from.add_vector(moved.normalize().scale(moved.length().min(8.0)));
+    let hit = horizon_core::geometry::traverse_blocks(from, to, 1_000_000, |p| {
+        let water = water_clip(world, fluids, from, to, p);
+        let reset = tagged(p)
+            && horizon_core::geometry::VoxelShape::block()
+                .clip(from, to, p)
+                .is_some();
+        (water || reset).then_some(())
+    });
+    matches!(hit, Ok(Some(())))
+}
 /// `ClipContext.Fluid.WATER` in a fall-reset ray through `p`: the water's
 /// shape from the shared `FlowingFluid.shapes` cache (the first query of a
 /// fluid state fixes its height), as the player's own ray reads it.
@@ -233,7 +233,7 @@ fn is_animal(id: &str) -> bool {
 use crate::mobs::persistent_anger;
 /// The single player's UUID (`offline_uuid("Player")`): the entity the
 /// neutral mobs are angry at.
-fn player_uuid() -> [i32; 4] {
+pub(crate) fn player_uuid() -> [i32; 4] {
    let u = horizon_protocol::crypto::offline_uuid("Player");
    [
        (u >> 96) as u32 as i32,
@@ -1297,7 +1297,7 @@ pub fn mob_to_nbt(
            crate::mobs::nautilus::to_nbt(m, map);
        }
        "minecraft:sulfur_cube" => crate::mobs::sulfur_cube::to_nbt(m, map),
-        "minecraft:bee" => crate::mobs::bee::to_nbt(m, map),
+        "minecraft:bee" => crate::mobs::bee::to_nbt(m, map, &mut uuid_of),
        "minecraft:sniffer" => crate::mobs::sniffer::to_nbt(m, map),
        "minecraft:wither" => {
            map.insert("Invul".into(), Tag::Int(m.extra.counter));
@@ -2666,9 +2666,9 @@ pub fn mob_from_nbt_with_random(
        m.extra.counter = number(tag.get("still_timeout")).unwrap_or(0) as i32;
    }
    if m.species() == crate::mobs::Species::Shulker {
-        m.extra.variant3 = number(tag.get("AttachFace")).unwrap_or(0).clamp(0, 5) as u8;
-        m.extra.counter = number(tag.get("Peek")).unwrap_or(0).clamp(0, 100) as i32;
-        m.extra.color = number(tag.get("Color")).map_or(16, |c| c.clamp(0, 16) as u8);
+        m.extra.variant3 = (number(tag.get("AttachFace")).unwrap_or(0) % 6).unsigned_abs() as u8;
+        m.extra.counter = number(tag.get("Peek")).map_or(0, |v| v as i8 as i32);
+        m.extra.color = number(tag.get("Color")).map_or(16, |v| v as i8 as u8);
        m.anim.v[0] = m.extra.counter as f32 * 0.01;
        m.anim.vo[0] = m.anim.v[0];
        // Shulker.setPos: square on its block.
@@ -13,6 +13,8 @@ pub fn main_with(mods: crate::mod_api::Mods) {
        log::warn!("Trait mods already installed; ignoring the second list");
    }
    horizon_threads::configure_allocator();
+    // OptiFine's and Polytone's pack formats (platform, docs/layers.md), before any pack loads.
+    horizon_client::pack_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
@@ -21,13 +23,9 @@ 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);
-    // Auto-reconnect, a Horizon extra still in the engine crates, runs on the connection hooks as
-    // the crates above do (horizon_client::reconnect; docs/layers.md, plan M5).
-    if cfg!(feature = "horizon-extras") {
-        let _ = horizon_hooks::register(&horizon_client::reconnect::HOOKS);
-    }
-    // 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();
@@ -189,52 +189,6 @@ impl hud::Canvas for Canvas<'_> {
    }
 }

-/// Draws on an open container screen (`horizon_hooks::containers`): `draw` gets a canvas whose
-/// (0, 0) is the panel's top left corner, at `origin` on the screen. It has no corners: `place`
-/// answers `None`.
-pub fn draw_on_panel(
-    batch: &mut HudBatch,
-    atlas: &HudAtlas,
-    origin: (f32, f32),
-    draw: impl FnOnce(&mut dyn hud::Canvas),
-) {
-    draw(&mut Panel {
-        batch,
-        atlas,
-        origin,
-    });
-}
-
-struct Panel<'a> {
-    batch: &'a mut HudBatch,
-    atlas: &'a HudAtlas,
-    origin: (f32, f32),
-}
-
-impl hud::Canvas for Panel<'_> {
-    fn size(&self) -> (f32, f32) {
-        (self.batch.width, self.batch.height)
-    }
-    fn tr(&self, key: &str) -> String {
-        crate::lang::get(key)
-    }
-    fn text_width(&self, text: &str) -> f32 {
-        HudBatch::text_width(self.atlas, text)
-    }
-    fn text(&mut self, x: f32, y: f32, text: &str, argb: u32, shadow: bool) {
-        let (x, y) = (self.origin.0 + x, self.origin.1 + y);
-        self.batch
-            .text(self.atlas, text, x, y, argb_color(argb), shadow);
-    }
-    fn fill(&mut self, x: f32, y: f32, w: f32, h: f32, argb: u32) {
-        let (x, y) = (self.origin.0 + x, self.origin.1 + y);
-        self.batch.fill(self.atlas, x, y, w, h, argb_color(argb));
-    }
-    fn place(&mut self, _: hud::Corner, _: f32, _: f32) -> Option<(f32, f32)> {
-        None
-    }
-}
-
 #[cfg(test)]
 mod tests {
    use super::*;
@@ -237,7 +237,6 @@ mod llamas;
 mod loading_screen;
 mod loading_window;
 mod locator_bar;
-mod look;
 mod loom;
 mod mace;
 mod machines;
@@ -374,6 +373,7 @@ 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)]
@@ -384,6 +384,7 @@ mod potions;
 mod powder_snow;
 mod prediction;
 mod pumpkin;
+mod pvp;
 mod quick_actions;
 mod raids;
 mod random_textures;
@@ -402,6 +403,7 @@ mod remote_vehicles;
 mod render_control;
 mod render_settings;
 mod render_tick;
+mod replay;
 mod repro;
 mod resource_load;
 mod resource_loader;
@@ -467,6 +469,7 @@ mod trial_spawner;
 mod trial_visuals;
 mod trident;
 mod tutorial;
+mod tweaks;
 mod ui_control;
 mod use_hand;
 mod using_item;
@@ -649,7 +652,7 @@ enum Screen {
    /// WorldOptionsScreen (game/lan_screen.rs).
    WorldOptions,
    /// Play with Friends, from the pause menu's Friends button
-    /// (`friends_screen`, game/friends.rs).
+    /// (game/friends.rs, game/friends/screen.rs).
    Friends,
    /// `SocialInteractionsScreen` (`social_screen`, game/social.rs).
    Social,
@@ -2017,8 +2020,8 @@ pub struct PackResources {
    clouds: Arc<(u32, u32, Vec<bool>)>,
    /// misc/forcefield.png: (width, height, RGBA) for the world border wall.
    forcefield: Arc<(u32, u32, Vec<u8>)>,
-    /// OptiFine custom sky layers (`optifine/sky`) with their textures; empty without them.
-    custom_sky: Arc<horizon_client::custom_sky::CustomSky>,
+    /// Custom sky layers (OptiFine's `optifine/sky`) with their textures; none without them.
+    custom_sky: Arc<dyn horizon_client::custom_sky::SkyLayers>,
    /// The overworld's, Nether's and End's attribute stacks with the packs' Polytone biome and
    /// dimension modifiers (#11486), when a pack has some: what the frame draws.
    environments: Option<Arc<[Environment; 3]>>,
@@ -2027,7 +2030,7 @@ pub struct PackResources {
    /// The packs' Polytone post chains (#11486), when a pack has some.
    polytone_post: Option<Arc<horizon_client::polytone_post::PolytonePost>>,
    /// The packs' Polytone custom colours (`polytone/colors.json`).
-    polytone_colors: Arc<horizon_client::polytone_colors::PackColors>,
+    polytone_colors: Arc<horizon_client::pack_palette::PackColors>,
 }
 /// A quick craft drag as the screen draws it: each dragged slot's count and
 /// whether the slot caps it (None: hidden), and what stays in hand.
@@ -2221,7 +2224,7 @@ struct Game<'a> {
    /// `AbstractContainerScreen`'s quick craft and skip-release state.
    inv_clicks: horizon_client::container_screen::Clicks,
    /// The Mouse Tweaks extra's drag and wheel (`tweaks`).
-    tweaks: extras::mouse_tweaks::Tweaks,
+    tweaks: tweaks::Tweaks,
    /// The wheel and hovered slot of `BundleMouseActions`.
    bundle_mouse: bundles::BundleMouse,
    /// The last inventory click, for the double click that gathers a stack.
@@ -2810,9 +2813,10 @@ struct Game<'a> {
    pending_bench: Option<(Instant, std::sync::mpsc::Sender<String>)>,
    /// Recent frame times for the performance overlay.
    frame_graph: horizon_client::perf_overlay::FrameGraph,
-    /// Horizon's extras (mods' minimap and counters; PvP & HUD's): `game/extras.rs`.
+    /// Horizon's extras (minimap, auto-reconnect; mods' counters): `game/extras.rs`.
    extras: extras::ExtrasState,
-    pvp: extras::pvp::PvpState,
+    /// The PvP & HUD options' state (`game/pvp.rs`).
+    pvp: pvp::PvpState,
    /// Horizon mods (`game/mods.rs`), none running unless turned on.
    mods: mods::ModsState,
    /// Every item and recipe, for mods (`game/native_recipes.rs`), made once.
@@ -2877,22 +2881,12 @@ struct Game<'a> {
    entity_attachments: HashMap<[i32; 4], horizon_world::attachments::Attachments>,
    /// Connected to a server: the world comes from the network (game/remote.rs).
    remote: Option<remote::Remote>,
-    /// The multiplayer server connected to last, and whether it is a Realm; the connection's
-    /// lifecycle reaches the hooks through it (`last_server.rs`).
-    last_server: horizon_client::last_server::LastServer,
-    /// 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,
+    /// The open connection joined from Realms: `ServerData.isRealm` for the friends
+    /// service's presence status.
+    realm_session: bool,
+    /// 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.
@@ -5024,7 +5018,7 @@ 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);
@@ -5488,34 +5482,6 @@ impl Game<'_> {
        );
        cancel
    }
-    /// The ticks the frame shows (animated textures, the HUD, a shader pack's clock): the
-    /// client's, or under `HORIZON_STILL` (`FixedStep::still`) the world's game time, which
-    /// moves only while the world runs.
-    pub(super) fn visual_ticks(&self) -> u64 {
-        if self.clock.still() {
-            self.world.game_time.max(0) as u64
-        } else {
-            self.ticks
-        }
-    }
-    /// The clock of the animated textures: `Minecraft.runTick` ticks the `TextureManager`
-    /// only while the level runs normally. Under `HORIZON_STILL` it is the world's ticks.
-    pub(super) fn texture_clock(&self) -> u64 {
-        if self.clock.still() {
-            self.visual_ticks()
-        } else {
-            self.texture_ticks
-        }
-    }
-    /// `Util.getMillis` for what the frame shows (the world border's scroll, the hearts' blink,
-    /// the glint's under the switch): under `HORIZON_STILL`, the world's ticks in milliseconds.
-    pub(super) fn visual_millis(&self) -> i64 {
-        if self.clock.still() {
-            self.visual_ticks() as i64 * 50
-        } else {
-            self.started.elapsed().as_millis() as i64
-        }
-    }
    /// `PresenceHandler.getPresenceStatus`: what an all-sharing player is doing, for
    /// the friends service's `updatePresence`.
    fn presence_status(&self) -> horizon_client::social::PresenceStatus {
@@ -5530,7 +5496,7 @@ impl Game<'_> {
            }
        } else if self.remote.is_some() {
            // `getCurrentServer().isRealm()`: the connection came from Realms.
-            if self.last_server.realm {
+            if self.realm_session {
                PresenceStatus::PlayingRealms
            } else {
                PresenceStatus::PlayingServer
@@ -5871,9 +5837,9 @@ 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.glint_texel();
+        batch.glint_colour = self.settings.extras.pvp.tweaks.glint_texel();
        // GlobalSettingsUniform's GameTime, for a resource pack's text shader.
        batch.game_time = ((self.world.game_time.rem_euclid(24000)) as f32
            + self.clock.fraction() as f32)
@@ -5968,8 +5934,7 @@ 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.
@@ -5986,7 +5951,8 @@ impl Game<'_> {
            // Hud.extractCrosshair / extractItemHotbar / extractPlayerHealth /
            // extractVehicleHealth and the experience bar, laid out by hud_layout.
            // Combat feel Legacy hides the attack indicator unless the player keeps it.
-            let indicator = if self.attack_indicator_hidden() {
+            let combat = self.settings.extras.pvp.combat;
+            let indicator = if combat.legacy && !combat.indicator {
                0
            } else {
                self.settings.attack_indicator
@@ -6050,7 +6016,7 @@ impl Game<'_> {
            });
            self.gui_layer("minecraft:effects", &mut batch, |g, batch| {
                // The PvP & HUD effects widget takes the icons' place.
-                if !g.effect_icons_hidden() {
+                if !g.pvp_effects_shown() {
                    g.draw_effect_icons(batch);
                }
            });
@@ -6167,7 +6133,7 @@ impl Game<'_> {
                    let atlas = &g.gui.atlas;
                    let width = |s: &str| HudBatch::text_width(atlas, s) as i32;
                    let draws = hud_layout::experience_colored(
-                        g.pack.polytone_colors.xp_bar(),
+                        g.pack.polytone_colors.xp_bar,
                        wi,
                        hi,
                        g.experience.progress,
@@ -6307,23 +6273,7 @@ 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);
        }
@@ -6485,7 +6435,7 @@ impl Game<'_> {
        self.draw_hovered_slot_highlight(batch, false, ox, oy);
        self.draw_inventory_slots(batch, ox, oy);
        self.draw_hovered_slot_highlight(batch, true, ox, oy);
-        self.draw_container_extras(batch, ox, oy);
+        self.draw_sort_buttons(batch, ox, oy);
        self.draw_recipe_book(batch);
        let effect_tip = if self.container.is_none() && self.craft_size == 2 && !self.mount_active()
        {
@@ -6500,18 +6450,6 @@ impl Game<'_> {
            self.draw_tooltip_lines(batch, &lines, self.cursor.0, self.cursor.1);
        }
    }
-    /// `AbstractContainerScreen` keeps `isQuickCrafting` and the drag it
-    /// belongs to on the screen. Horizon keeps both on `Game` (`inv_clicks`,
-    /// `inv_drag`, `last_inv_click`), so they are dropped when the pointer
-    /// changes hands: a screen that opens or closes starts with its own
-    /// state, and a press whose release never reached the screen -- the
-    /// pointer left the window, or the screen closed first -- would
-    /// otherwise leave every later press on every later screen swallowed.
-    pub(super) fn reset_inventory_clicks(&mut self) {
-        self.inv_clicks.cancel_drag();
-        self.inv_drag = None;
-        self.last_inv_click = None;
-    }
    pub(super) fn close_container(&mut self) {
        // `Gui.setScreen` clears the old screen's focus before it goes: the
        // key that closed the container (Tab bound to the inventory) has
@@ -6555,29 +6493,15 @@ impl Game<'_> {
        }
        self.close_ender_chest();
    }
-    /// A sound a menu click made the player play (a bundle's insert or
-    /// remove): `Entity.playSound` at the player.
-    pub(super) fn player_menu_sound(&mut self, sound: &str) {
-        let Some(p) = self.player.as_ref() else {
-            return;
-        };
-        let at = [p.position.x, p.position.y, p.position.z];
-        let (volume, pitch) = if sound == horizon_client::bundle::INSERT_FAIL {
-            (1.0, 1.0)
-        } else {
-            (0.8, 0.8 + self.world.random.next_float() * 0.4)
-        };
-        self.audio.play(sound, Some(at), volume, pitch);
-    }
    /// `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.
@@ -6784,11 +6708,7 @@ 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() {
@@ -7517,7 +7437,6 @@ impl Game<'_> {
        self.spawn_phantoms();
        self.tick_advancements();
        self.tick_player_model();
-        self.tick_emotes();
        Ok(())
    }

@@ -9287,7 +9206,7 @@ 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)
@@ -9465,14 +9384,7 @@ 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");
@@ -9494,7 +9406,7 @@ 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)
@@ -9620,7 +9532,7 @@ 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 {
@@ -9895,7 +9807,7 @@ impl Game<'_> {
            outline,
            outline_after_terrain,
            outline_high_contrast: self.settings.file.bool("highContrastBlockOutline"),
-            look: self.look_frame(),
+            pvp: self.settings.extras.pvp.frame(),
            debug_lines: &debug_lines,
            debug_lines_on_top: &debug_lines_on_top,
            debug_crosshair: &debug_crosshair,
@@ -10125,7 +10037,7 @@ impl Game<'_> {
                )
            )
        {
-            self.pad.keyboard_took_over = true;
+            self.input_keyboard_used();
        }
        if let WindowEvent::KeyboardInput { event, .. } = &event
            && event.state == ElementState::Pressed
@@ -10513,21 +10425,7 @@ 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) {
@@ -10578,7 +10476,7 @@ 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)),
@@ -10706,7 +10604,7 @@ impl Game<'_> {
                    if self.screen == Screen::Inventory
                        && d != 0.0
                        && !bundle
-                        && !self.container_scroll(d)
+                        && !self.tweak_scroll(d, self.inventory_target().0)
                    {
                        self.station_scroll(d);
                    }
@@ -10855,90 +10753,7 @@ 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)
@@ -10954,7 +10769,7 @@ impl Game<'_> {
                        return Ok(());
                    }
                    if pressed
-                        && (self.container_mouse_press(button)
+                        && (self.sort_mouse_press(button)
                            || self.hud_editor_key_press(&horizon_client::keybinds::mouse_name(
                                button,
                            )))
@@ -11408,24 +11223,7 @@ 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
@@ -11496,9 +11294,9 @@ impl Game<'_> {
                        }
                    }
                    self.extras_frame(elapsed);
-                    self.reconnect_when_due()?;
+                    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();
@@ -11607,20 +11405,21 @@ impl Game<'_> {
                            self.settings.simulation_distance,
                            self.settings.entity_distance,
                        );
-                        server.set_legacy_rules(self.pvp_legacy_rules());
+                        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()
                    {
@@ -11633,7 +11432,6 @@ impl Game<'_> {
                            }
                            .to_string(),
                        );
-                        consumed = true;
                    }
                    if let Some(result) =
                        self.renderer.as_mut().and_then(|r| r.capture_result.take())
@@ -11642,12 +11440,6 @@ 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);
@@ -12207,17 +11999,9 @@ impl<'a> Game<'a> {
            persist: Default::default(),
            entity_attachments: Default::default(),
            remote: None,
-            last_server: Default::default(),
-            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,
+            realm_session: false,
+            replay: Default::default(),
+            studio: Default::default(),
            lan: None,
            integrated: None,
            level_shapes: Default::default(),
@@ -12716,17 +12500,8 @@ 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));
-        let player_dir = horizon_client::logging::player_dir();
-        // horizon-extras: the official server is Horizon's (docs/forking.md).
-        if cfg!(feature = "horizon-extras")
-            && let Err(e) = horizon_client::multiplayer::add_official_server(&player_dir)
-        {
-            log::warn!("could not add the official server to servers.dat: {e}");
-        }
-        if let Err(e) = horizon_client::multiplayer::withdraw_partner_servers(&player_dir) {
-            log::warn!("could not take the withdrawn partner server out of servers.dat: {e}");
-        }
+        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();
@@ -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));
    }
@@ -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) {
@@ -686,23 +686,15 @@ impl Game<'_> {
        if fall == 0.0 || length < 1.0 {
            return fall;
        }
-        let to = from.add_vector(moved.normalize().scale(moved.length().min(8.0)));
        let reset = &self.res.motion().fall_reset;
-        let fluids = &self.res.motion().fluids;
-        let hit = horizon_core::geometry::traverse_blocks(from, to, 1_000_000, |p| {
-            // A tagged block clips as a full block, not its collider.
-            let name = &self.res.facts().get(self.world.block(p.x, p.y, p.z)).name;
-            if reset.contains(&**name) && VoxelShape::block().clip(from, to, p).is_some() {
-                return Some(());
-            }
-            // The water's shape, through the shared fluid shape cache.
-            horizon_client::entities::water_clip(&self.world, fluids, from, to, p).then_some(())
-        });
-        if matches!(hit, Ok(Some(()))) {
-            0.0
-        } else {
-            fall
-        }
+        let hit = horizon_client::entities::fall_reset_hit(
+            &self.world,
+            &self.res.motion().fluids,
+            |p| reset.contains(&*self.res.facts().get(self.world.block(p.x, p.y, p.z)).name),
+            from,
+            moved,
+        );
+        if hit { 0.0 } else { fall }
    }
    /// `AbstractBoat.checkFallDamage` after a move that went `moved_y` (with
    /// `b` already where it landed): on the ground the fall resets; a move
@@ -33,6 +33,8 @@ fn book_title_box() -> ui::EditBox {
    edit.bordered = false;
    edit.max_length = 15;
    edit.text_color = BLACK;
+    // BookSignScreen sets the title box centred.
+    edit.centered = true;
    edit.focused = true;
    edit
 }
@@ -68,6 +70,23 @@ pub(super) enum BookScreen {
        lectern: Option<(i32, i32, i32)>,
    },
 }
+impl BookScreen {
+    /// `BookSignScreen`'s constructor: its title box opens with the title
+    /// kept from the last time, which Cancel stored (`titleValue`).
+    fn begin_signing(&mut self) {
+        if let Self::Edit {
+            signing,
+            title,
+            title_edit,
+            ..
+        } = self
+        {
+            *signing = true;
+            title_edit.set_value(title.as_str());
+            title_edit.reset_blink();
+        }
+    }
+}
 /// The pages a book screen reads: a written book's components (so their
 /// click events stay), else a writable book's text.
 fn view_pages(data: Option<&StackData>) -> Vec<Text> {
@@ -986,7 +1005,7 @@ impl Game<'_> {
                    title,
                    ..
                }) if !title.trim().is_empty() => self.save_book(true),
-                Some(BookScreen::Edit { signing, .. }) => *signing = true,
+                Some(book @ BookScreen::Edit { .. }) => book.begin_signing(),
                _ => return Err("not a book and quill".into()),
            },
            Some("done") => match self.book.as_mut() {
@@ -1188,8 +1207,8 @@ impl Game<'_> {
                    self.turn_page(false);
                } else if inside(w / 2.0 - 100.0, 196.0, 98.0, 20.0) {
                    click(self);
-                    if let Some(BookScreen::Edit { signing, .. }) = self.book.as_mut() {
-                        *signing = true;
+                    if let Some(book) = self.book.as_mut() {
+                        book.begin_signing();
                    }
                } else if inside(w / 2.0 + 2.0, 196.0, 98.0, 20.0) {
                    click(self);
@@ -1618,6 +1637,19 @@ pub(super) fn lectern_signal(world: &horizon_client::world::World, pos: BlockPos
    }
 }

+#[cfg(test)]
+mod title_box_tests {
+    use super::book_title_box;
+
+    /// `BookSignScreen` sets its 15 character title box centred and unbordered.
+    #[test]
+    fn the_sign_title_box_is_centred() {
+        let edit = book_title_box();
+        assert!(edit.centered);
+        assert!(!edit.bordered);
+        assert_eq!(edit.max_length, 15);
+    }
+}
 #[cfg(test)]
 mod lectern_books_tag_tests {
    use super::super::native_machines::tests::server_game;
@@ -1794,3 +1826,46 @@ mod lectern_reach_tests {
        );
    }
 }
+
+#[cfg(test)]
+mod sign_tests {
+    use super::{BookScreen, book_page_box, book_title_box};
+
+    /// `BookSignScreen`'s constructor sets its title box to `titleValue`, what
+    /// Cancel kept; reopening the sign screen shows the title typed before,
+    /// not an empty box beside a stale `title`.
+    #[test]
+    fn the_sign_screen_opens_with_the_title_it_kept() {
+        let mut book = BookScreen::Edit {
+            slot: 0,
+            pages: vec!["page".into()],
+            page: 0,
+            signing: false,
+            title: "My Book".into(),
+            title_edit: book_title_box(),
+            page_edit: book_page_box(),
+        };
+        assert_eq!(book_title_value(&book), "");
+        book.begin_signing();
+        let BookScreen::Edit {
+            signing,
+            title,
+            title_edit,
+            ..
+        } = &book
+        else {
+            panic!("the book stays open");
+        };
+        assert!(signing);
+        assert_eq!(title.as_str(), "My Book");
+        assert_eq!(title_edit.value, "My Book");
+        assert_eq!(title_edit.cursor, 7);
+    }
+
+    fn book_title_value(book: &BookScreen) -> String {
+        match book {
+            BookScreen::Edit { title_edit, .. } => title_edit.value.clone(),
+            BookScreen::View { .. } => String::new(),
+        }
+    }
+}
@@ -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.
@@ -1278,7 +1278,7 @@ impl Game<'_> {
        let ctrl = self.has_control_down_with_quirk();
        let shift = self.has_shift_down();
        // PvP & HUD's chat search: Ctrl+F starts and stops it, Enter stops it (sends nothing).
-        if self.chat_look().search
+        if self.settings.extras.pvp.chat.search
            && match key {
                KeyCode::KeyF => ctrl,
                KeyCode::Enter | KeyCode::NumpadEnter => self.pvp.chat_search,
@@ -1487,7 +1487,7 @@ impl Game<'_> {
            cursor.1 as f64,
        );
        // PvP & HUD's copy on click: a message where the click has nothing else to do.
-        if self.chat_look().copy
+        if self.settings.extras.pvp.chat.copy
            && !self.has_shift_down()
            && style.as_ref().is_none_or(|s| s.click.is_none())
            && let Some(message) =
@@ -1665,8 +1665,8 @@ impl Game<'_> {
    /// Chat lines over the HUD (focused while the chat screen is open).
    pub(super) fn draw_chat(&mut self, batch: &mut HudBatch) {
        let focused = self.screen == Screen::Chat;
-        let options = self.chat_look();
-        self.ui.chat.set_qol(&self.gui.atlas, self.chat_qol());
+        let options = self.settings.extras.pvp.chat;
+        self.ui.chat.set_qol(&self.gui.atlas, options.qol());
        // A search ends with its option; a chat closed some other way ends it in keep_chat_draft.
        if self.pvp.chat_search && self.ui.chat_screen.is_none() {
            // The chat went without closing (leaving the world): nothing to give back.
@@ -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()));
@@ -42,8 +42,8 @@ impl Reply {
    }

    pub(super) fn duration(millis: i64) -> Text {
-        use horizon_chat_filter::DurationUnit;
-        let (count, unit) = horizon_chat_filter::duration_parts(millis);
+        use horizon_server_files::duration::{DurationUnit, duration_parts};
+        let (count, unit) = duration_parts(millis);
        let key = match (unit, count == 1) {
            (DurationUnit::Minute, true) => "horizon.moderation.duration.minute",
            (DurationUnit::Minute, false) => "horizon.moderation.duration.minutes",
@@ -93,7 +93,7 @@ pub(super) const MUTE_USAGES: [&str; 4] = [
 fn mute_time(words: &[&str]) -> (Option<i64>, usize) {
    match words
        .get(2)
-        .and_then(|w| horizon_chat_filter::parse_duration(w))
+        .and_then(|w| horizon_server_files::duration::parse_duration(w))
    {
        Some(ms) => (Some(ms), 3),
        None => (None, 2),
@@ -133,7 +133,7 @@ impl Game<'_> {
        count: u32,
        action: Action,
    ) {
-        let now = horizon_chat_filter::now_millis();
+        let now = horizon_server_files::duration::now_millis();
        let summary = format!(
            "[chat-filter] Refused {name}'s {} (hit {count}: {})",
            place.name(),
@@ -281,7 +281,7 @@ impl Game<'_> {
        let reason = |from: usize| (words.len() > from).then(|| words[from..].join(" "));
        match words {
            ["mutelist"] => {
-                let now = horizon_chat_filter::now_millis();
+                let now = horizon_server_files::duration::now_millis();
                let mutes = host.hub.mutes();
                if mutes.is_empty() {
                    return vec![Reply::translated("horizon.moderation.mutelist.empty", &[])];
@@ -319,13 +319,15 @@ impl Game<'_> {
                let (time, from) = mute_time(words);
                vec![self.mute(host, name, time, reason(from), by)]
            }
-            ["tempmute", name, time, ..] => match horizon_chat_filter::parse_duration(time) {
-                Some(ms) => vec![self.mute(host, name, Some(ms), reason(3), by)],
-                None => vec![Reply::translated(
-                    "horizon.moderation.invalid_duration",
-                    &[Text::literal(*time)],
-                )],
-            },
+            ["tempmute", name, time, ..] => {
+                match horizon_server_files::duration::parse_duration(time) {
+                    Some(ms) => vec![self.mute(host, name, Some(ms), reason(3), by)],
+                    None => vec![Reply::translated(
+                        "horizon.moderation.invalid_duration",
+                        &[Text::literal(*time)],
+                    )],
+                }
+            }
            ["mute", ..] => vec![Reply::translated("horizon.moderation.usage.mute", &[])],
            ["tempmute", ..] => vec![Reply::translated("horizon.moderation.usage.tempmute", &[])],
            ["unmute", ..] => vec![Reply::translated("horizon.moderation.usage.unmute", &[])],
@@ -353,10 +355,10 @@ impl Game<'_> {
        let Some((uuid, name)) = user else {
            return Reply::no_player();
        };
-        let until = time.map(|ms| horizon_chat_filter::now_millis() + ms);
+        let until = time.map(|ms| horizon_server_files::duration::now_millis() + ms);
        let what = time.map_or_else(
            || "until unmuted".into(),
-            |ms| format!("for {}", horizon_chat_filter::duration_text(ms)),
+            |ms| format!("for {}", horizon_server_files::duration::duration_text(ms)),
        );
        let why = reason
            .as_deref()
@@ -227,16 +227,16 @@ impl Game<'_> {
            );
        }
        for m in self.mobs.iter() {
-            if !m.alive() {
+            // A mob with no effects swirls nothing: skipped before its size
+            // is worked out, which every mob in a crowded world would pay
+            // for (#14053).
+            if !m.alive() || (m.extra.effect_particles.is_empty() && m.extra.effects.is_empty()) {
                continue;
            }
            let size = (f64::from(m.width()), f64::from(m.height()));
            let invisible = m.invisible || m.has_effect("minecraft:invisibility");
            if m.extra.effect_particles.is_empty() {
                // A mob of this game: its own effects, visible and not ambient.
-                if m.extra.effects.is_empty() {
-                    continue;
-                }
                let list: Vec<_> = m
                    .extra
                    .effects
@@ -92,6 +92,7 @@ fn a_mods_fireworks_burst_and_bang_on_the_client_only() {
            facts: game.res.facts(),
            collision: game.collision,
            player: None,
+            cached_chunk: std::cell::Cell::new(None),
        };
        game.particles.tick(&level);
    };
@@ -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());
@@ -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)
@@ -1567,11 +1568,11 @@ impl Game<'_> {
            "streaming": self.streaming.stages().into_iter().map(|(k, v)| (k.to_string(), v.into())).collect::<serde_json::Map<_, _>>(),
            "dirty_light": self.world.dirty_light.len(),
            "renderer": renderer,
-            "display": self.window.as_deref().and_then(horizon_client::telemetry::monitor).map(|m| json!({
-                "width": m.size().width,
-                "height": m.size().height,
-                "scale": m.scale_factor(),
-                "refresh_hz": m.refresh_rate_millihertz().map(|r| r.div_ceil(1000)),
+            "display": self.window.as_deref().and_then(horizon_client::window::display).map(|d| json!({
+                "width": d.width,
+                "height": d.height,
+                "scale": d.scale,
+                "refresh_hz": d.refresh_hz,
            })),
            "uptime_seconds": self.started.elapsed().as_secs_f64(),
            "server": self.remote_status(),
@@ -623,3 +623,6 @@ fn stack_drop_requires_ctrl_even_with_sprint_latched() {
        }
    }
 }
+
+#[path = "play_ping_tests.rs"]
+mod play_ping_tests;
@@ -20,13 +20,17 @@ use horizon_cosmetics::follow::Follow;
 use horizon_cosmetics::prefs::{self, Others};
 use horizon_cosmetics::trail::{Budget, Emitter};
 use horizon_cosmetics::{Item, Slot};
+use horizon_hooks::players::{
+    Badge, CameraOverride, CameraView, Frame, Gear, Kind, Mark, NameDecoration, PlayerModel,
+    PlayerModels, SpriteStore, Sprites,
+};
 use std::cell::{Cell, RefCell};
-use std::sync::Arc;
 use std::sync::mpsc::{Receiver, channel};
+use std::sync::{Arc, Mutex, PoisonError};
 use std::time::{Duration, Instant};

 /// Horizon's mark before a Horizon player's name, over their name tag and in the player list.
-pub(super) const MARK: horizon_client::tab_list::NameMark = &horizon_cosmetics::mark::MARK;
+const MARK: Mark = &horizon_cosmetics::mark::MARK;

 /// An item as the renderer takes it.
 struct Baked {
@@ -55,7 +59,8 @@ impl Baked {

 #[derive(Default)]
 pub(super) struct Cosmetics {
-    client: Option<horizon_cosmetics::Cosmetics>,
+    /// The hooks' client (`Seat`), taken once it started.
+    client: Option<Arc<horizon_cosmetics::Cosmetics>>,
    /// By the item's address; each entry holds its item, so the address isn't reused.
    baked: RefCell<FxHashMap<usize, Baked>>,
    /// Items drawn whose texture isn't in the atlas yet.
@@ -65,16 +70,6 @@ pub(super) struct Cosmetics {
    poses: RefCell<(Poses, Poses)>,
    /// Item files from a folder (`HORIZON_COSMETICS_LOCAL`): mannequins wear them too.
    local: bool,
-    /// Show my cosmetics on its way to the service.
-    mine: AccountSync,
-    /// Show me as a Horizon player: sent at start, on each change and every hour while on.
-    listed: AccountSync,
-    /// Whether the signed-in account owns a cosmetic.
-    owner: OwnerCheck,
-    /// Which other players play an emote (`horizon_cosmetics::Feed`), started with the client.
-    feed: Option<horizon_cosmetics::Feed>,
-    /// My emote on its way to the service.
-    emote_out: EmoteOut,
    /// Companions, trails and auras.
    fx: RefCell<Fx>,
    /// Emotes: those the wheel offers and the one playing (`cosmetics/emotes.rs`).
@@ -405,17 +400,13 @@ fn slot_image(item: &Item) -> Vec<u8> {

 /// Which slots an avatar's gear covers: a helmet or head item hides a hat, an elytra or a cape
 /// what is worn on the back. A name tag style is never drawn on the body.
-fn covered(m: &Mob, slot: Slot) -> bool {
+fn covered(gear: Gear, slot: Slot) -> bool {
    match slot {
-        Slot::Head => m.extra.head.is_some(),
-        Slot::Back => m.cape.is_some() || m.extra.chest.as_deref() == Some("minecraft:elytra"),
+        Slot::Head => gear.head,
+        Slot::Back => gear.back,
        Slot::Shoulder => false,
        // A chestplate, not an elytra.
-        Slot::Torso => m
-            .extra
-            .chest
-            .as_deref()
-            .is_some_and(|c| c != "minecraft:elytra"),
+        Slot::Torso => gear.chest,
        Slot::NameTag | Slot::Emote => true,
        // On no bone: drawn by a pass of their own, never on the body.
        Slot::Companion | Slot::Trail | Slot::Aura => true,
@@ -427,12 +418,12 @@ fn covered(m: &Mob, slot: Slot) -> bool {
 /// (`worn` is None), another player's at "name tags only" or hidden, or every item `covered` (a
 /// helmet over a hat). One max over at most five items, read when the item was parsed.
 fn body_top(
-    extras: &horizon_client::extras::Extras,
+    others: Others,
    own: bool,
    worn: Option<&horizon_cosmetics::Worn>,
    covered: impl Fn(Slot) -> bool,
 ) -> Option<f32> {
-    if !own && extras.effective_others() != Others::Shown {
+    if !own && others != Others::Shown {
        return None;
    }
    worn?
@@ -449,115 +440,424 @@ pub(super) fn enabled() -> bool {
    cfg!(feature = "horizon-extras") && horizon_cosmetics::enabled()
 }

+/// What the cosmetics' hooks keep for one splitscreen player (`horizon_hooks::seat`): the
+/// service's client, the emote feed and what the account tells the service.
+#[derive(Default)]
+struct Seat {
+    client: Option<Arc<horizon_cosmetics::Cosmetics>>,
+    /// Item files from a folder (`HORIZON_COSMETICS_LOCAL`).
+    local: bool,
+    /// Show my cosmetics on its way to the service.
+    mine: AccountSync,
+    /// Show me as a Horizon player: sent at start, on each change and every hour while on.
+    listed: AccountSync,
+    /// Whether the signed-in account owns a cosmetic.
+    owner: OwnerCheck,
+    /// Which other players play an emote (`horizon_cosmetics::Feed`), started with the client.
+    feed: Option<horizon_cosmetics::Feed>,
+    /// My emote on its way to the service.
+    emote_out: EmoteOut,
+    /// What the game's settings and the player's emote say (`Game::cosmetics_say`).
+    said: Said,
+    /// Kept between ticks so a tick allocates nothing: the player models in view.
+    models: Vec<PlayerModel>,
+    /// The world is the window's own single-player one (`Frame::solo`).
+    solo: bool,
+    /// Name tag badges' sprites, by the item's address: their id (never reused) and the item,
+    /// held so the address isn't reused while it is there.
+    sprites: FxHashMap<usize, (u64, Arc<Item>)>,
+    last_sprite: u64,
+    /// Sprites drawing missed, put in the atlas next frame.
+    wanted: Vec<u64>,
+}
+
+/// What the game tells the hooks before each call, until the settings move here (spec #14091
+/// step 5a) and the player's emote with them (step 4).
+#[derive(Default)]
+struct Said {
+    mine: bool,
+    listed: bool,
+    /// Other players' cosmetics are shown (not "name tags only", not hidden).
+    others_shown: bool,
+    /// Other players' cosmetics are hidden (not even name tag styles).
+    others_hidden: bool,
+    /// Horizon's mark by Horizon players' names.
+    marks: bool,
+    /// Cosmetics in single player: the signed-in account's on the player's own model.
+    solo: bool,
+    /// My emote pulled the camera back: when it started (the own model's age).
+    pull: Option<f32>,
+    /// My emote while it plays: its id and whether it loops.
+    playing: Option<(String, bool)>,
+    /// A folder's first emote, which mannequins play.
+    first: Option<Arc<Item>>,
+}
+
+/// One [`Seat`] per splitscreen player.
+static SERVICES: Mutex<Vec<Seat>> = Mutex::new(Vec::new());
+
+/// Runs `f` on this seat's [`Seat`]. Never called inside itself.
+fn service<R>(f: impl FnOnce(&mut Seat) -> R) -> R {
+    let seat = horizon_hooks::seat();
+    let mut all = SERVICES.lock().unwrap_or_else(PoisonError::into_inner);
+    if all.len() <= seat {
+        all.resize_with(seat + 1, Seat::default);
+    }
+    f(&mut all[seat])
+}
+
+/// The cosmetics' hooks, registered when [`enabled`].
+pub(super) struct Hooks;
+pub(super) static HOOKS: Hooks = Hooks;
+
+impl horizon_hooks::Hooks for Hooks {
+    fn frame(&self, frame: &Frame, sprites: &mut dyn SpriteStore) {
+        service(|s| {
+            s.solo = frame.solo;
+            s.frame();
+            s.put_sprites(sprites);
+        });
+    }
+
+    fn tick(&self, models: &mut dyn PlayerModels) {
+        service(|s| s.tick(models));
+    }
+
+    fn name_decoration(
+        &self,
+        model: &PlayerModel,
+        sprites: &dyn Sprites,
+    ) -> Option<NameDecoration> {
+        service(|s| s.name_decoration(model, sprites))
+    }
+
+    fn player_mark(&self, uuid: u128) -> Option<Mark> {
+        service(|s| {
+            let client = s.client.as_ref().filter(|_| s.said.marks)?;
+            client.frame().horizon(uuid).then_some(MARK)
+        })
+    }
+
+    /// An emote pulls the camera back: it eases out over the emote's first quarter second.
+    fn camera(&self, own: &CameraView) -> Option<CameraOverride> {
+        let start = service(|s| s.said.pull)?;
+        let t = ((own.age - start) / 5.0).clamp(0.0, 1.0);
+        Some(CameraOverride::new(0.35 + 0.65 * t * t * (3.0 - 2.0 * t)))
+    }
+}
+
+impl Seat {
+    /// Once a frame: starts the service's client on first use, asks whether the account owns a
+    /// cosmetic, and tells the service what the account shows.
+    fn frame(&mut self) {
+        if self.client.is_none() {
+            let (client, local) = Cosmetics::client();
+            self.client = Some(Arc::new(client));
+            self.local = local;
+            // Others' emotes come from the service only (a local folder has no one playing).
+            if !local {
+                self.feed = Some(horizon_cosmetics::Feed::new(http()));
+            }
+        }
+        // Item files from a folder (the art, the bench): shown as to an owner, nothing asked.
+        if self.local {
+            self.owner.owns = true;
+            return;
+        }
+        // Whether the account owns a cosmetic: what the last run learnt, then the service.
+        let o = &mut self.owner;
+        if !o.started {
+            o.started = true;
+            o.owns = account()
+                .is_some_and(|(_, uuid, home)| prefs::owned(&home, &uuid).unwrap_or(false));
+        }
+        if let Some(done) = o.asking.as_ref().and_then(|rx| rx.try_recv().ok()) {
+            o.asking = None;
+            match done {
+                Ok(owns) => (o.owns, o.known, o.retry) = (owns, true, None),
+                Err(_) => o.retry = backoff(o.retry),
+            }
+        }
+        // One sign-in at a time: Mojang keeps one joined server id per account.
+        let due = !o.known && o.retry.is_none_or(|(at, _)| Instant::now() >= at);
+        if due && o.asking.is_none() && self.mine.sending.is_none() && self.listed.sending.is_none()
+        {
+            let (tx, rx) = channel();
+            o.asking = Some(rx);
+            std::thread::Builder::new()
+                .name("Cosmetics account".into())
+                .spawn(move || {
+                    let _ = tx.send(check_owner());
+                })
+                .ok();
+        }
+        // Show my cosmetics: sent once per change of the wish, then retried until confirmed.
+        // Show me as a Horizon player: also said again every hour while on.
+        let every = horizon_cosmetics::account::PRESENCE_EVERY;
+        self.mine.settle(None);
+        self.listed.settle(Some(every));
+        // One sign-in at a time, as for the ownership check above.
+        let busy = self.owner.asking.is_some()
+            || self.mine.sending.is_some()
+            || self.listed.sending.is_some();
+        let said = &self.said;
+        if let Some(done) = self
+            .emote_out
+            .sending
+            .as_ref()
+            .and_then(|rx| rx.try_recv().ok())
+        {
+            self.emote_out.sending = None;
+            match done {
+                Ok(()) => self.emote_out.retry = None,
+                Err(_) => {
+                    self.emote_out.retry = backoff(self.emote_out.retry);
+                    self.emote_out.sent = None;
+                }
+            }
+        }
+        // My emote: only while I show myself as a Horizon player (playing one says so).
+        let playing = said.playing.as_ref();
+        let looping = playing.is_some_and(|(_, looping)| *looping);
+        let wish = playing.map(|(id, _)| id.as_str()).filter(|_| said.listed);
+        let o = &mut self.emote_out;
+        let changed = o.sent.as_ref().map(Option::as_deref) != Some(wish);
+        let again = looping && o.again.is_some_and(|at| Instant::now() >= at);
+        let waited = o.retry.is_none_or(|(at, _)| Instant::now() >= at);
+        // Nothing sent yet and nothing playing: nothing to say (a failed send forgets what
+        // was sent: the service ends a one-shot by itself, a loop within a minute).
+        let quiet = wish.is_none() && o.sent.is_none();
+        let emote_due = !quiet && waited && (changed || again);
+        // One sign-in at a time, the emote's included.
+        if busy || o.sending.is_some() {
+        } else if emote_due {
+            let wish = wish.map(str::to_owned);
+            o.sent = Some(wish.clone());
+            o.again = looping.then(|| Instant::now() + LOOP_AGAIN);
+            let (tx, rx) = channel();
+            o.sending = Some(rx);
+            let kept = o.kept.clone();
+            std::thread::Builder::new()
+                .name("Cosmetics emote".into())
+                .spawn(move || {
+                    let _ = tx.send(send_emote(&kept, wish.as_deref()));
+                })
+                .ok();
+        } else if self.mine.due(said.mine) {
+            self.mine.start(said.mine, send_mine);
+        } else if self.listed.due(said.listed) {
+            self.listed.start(said.listed, send_listed);
+        }
+    }
+
+    /// What goes by `m`'s name: Horizon's mark if they play Horizon (and the mark is on), the
+    /// name tag style they wear if cosmetics are shown for them (name tags only counts), and how
+    /// high what is drawn on their body gets (`body_top`). One look in the cache for all three.
+    fn name_decoration(
+        &mut self,
+        m: &PlayerModel,
+        sprites: &dyn Sprites,
+    ) -> Option<NameDecoration> {
+        let said = &self.said;
+        let own = m.kind == Kind::Own;
+        let styles = if own { said.mine } else { !said.others_hidden };
+        if !(styles || said.marks) {
+            return None;
+        }
+        let uuid = match m.kind {
+            Kind::Own => own_uuid(m.uuid, self.solo, said.solo, || {
+                horizon_client::auth::current().map(|s| s.uuid)
+            }),
+            Kind::Mannequin if self.local => Some(u128::from(m.id)),
+            Kind::Player => m.uuid,
+            _ => None,
+        }?;
+        let mut frame = self.client.as_ref()?.frame();
+        let mark = (said.marks && frame.horizon(uuid)).then_some(MARK);
+        let worn = if styles { frame.worn(uuid) } else { None };
+        drop(frame);
+        let others = if said.others_shown {
+            Others::Shown
+        } else {
+            Others::NameTags
+        };
+        let top = body_top(others, own, worn.as_ref(), |slot| covered(m.gear, slot))
+            .filter(|_| !m.invisible);
+        let badge = worn.and_then(|w| self.badge(&w, sprites));
+        Some(NameDecoration::new(mark, badge, top))
+    }
+
+    /// The name tag style in `worn`: its badge's place in the atlas and its line's colour. None
+    /// until the badge is in the atlas (it is put there next frame).
+    fn badge(&mut self, worn: &horizon_cosmetics::Worn, sprites: &dyn Sprites) -> Option<Badge> {
+        let item = worn.iter().find(|i| i.slot == Slot::NameTag)?;
+        let [r, g, b] = item.tag?.line;
+        let next = self.last_sprite + 1;
+        let (id, _) = *self
+            .sprites
+            .entry(Arc::as_ptr(item) as usize)
+            .or_insert_with(|| (next, item.clone()));
+        self.last_sprite = self.last_sprite.max(id);
+        let Some([u0, v0, u1, v1]) = sprites.get(id) else {
+            if !self.wanted.contains(&id) {
+                self.wanted.push(id);
+            }
+            return None;
+        };
+        // The mark sits in the slot's top left corner.
+        let u1 = u0 + (u1 - u0) * item.texture.width as f32 / 64.0;
+        let v1 = v0 + (v1 - v0) * item.texture.height as f32 / 64.0;
+        Some(Badge::new(
+            [u0, v0, u1, v1],
+            u32::from_be_bytes([0, r, g, b]),
+        ))
+    }
+
+    /// Puts the sprites drawing missed in the atlas; forgets those of items no one wears.
+    fn put_sprites(&mut self, store: &mut dyn SpriteStore) {
+        for id in self.wanted.drain(..) {
+            let item = self.sprites.values().find(|(i, _)| *i == id);
+            if let Some((_, item)) = item.filter(|_| !store.has(id)) {
+                store.put(id, slot_image(item));
+            }
+        }
+        self.sprites
+            .retain(|_, (_, item)| Arc::strong_count(item) > 1);
+    }
+
+    /// Once a tick: names the Horizon players in view to the emote feed and plays what it says
+    /// they play on their models; one that moved ends theirs here at once. Others' emotes show
+    /// with "Other players' cosmetics" on Shown only; otherwise nothing is asked.
+    fn tick(&mut self, models: &mut dyn PlayerModels) {
+        let mut seen = std::mem::take(&mut self.models);
+        seen.clear();
+        models.for_each(&mut |m| {
+            if m.kind != Kind::Own {
+                seen.push(m);
+            }
+        });
+        self.play_others(models, &mut seen);
+        self.models = seen;
+    }
+
+    fn play_others(&self, models: &mut dyn PlayerModels, view: &mut Vec<PlayerModel>) {
+        let shown = self.said.others_shown;
+        // Items from a folder (the art, the bench): every mannequin plays its first emote, again
+        // and again.
+        if self.local && shown {
+            let Some(first) = &self.said.first else {
+                return;
+            };
+            for m in view.iter().filter(|m| m.kind == Kind::Mannequin) {
+                let age = m.age as f32;
+                let now = emotes::pose_playing(models.body_pose(m.id));
+                if now.is_none_or(|p| p.at(age).is_none()) {
+                    let playing = horizon_cosmetics::Playing {
+                        item: first.clone(),
+                        // Out of step, so a crowd doesn't move as one.
+                        start: age - (m.id % 40) as f32,
+                        stop: None,
+                    };
+                    emotes::set_model_playing(models, m.id, Some(playing));
+                }
+            }
+            return;
+        }
+        let (Some(feed), Some(client)) = (&self.feed, &self.client) else {
+            return;
+        };
+        if !shown {
+            feed.ask([]);
+            for m in view.iter() {
+                emotes::set_model_playing(models, m.id, None);
+            }
+            return;
+        }
+        let mut frame = client.frame();
+        view.retain(|m| m.kind == Kind::Player && m.uuid.is_some_and(|u| frame.horizon(u)));
+        drop(frame);
+        feed.ask(view.iter().filter_map(|m| m.uuid));
+        let now = Instant::now();
+        for m in view.iter() {
+            let Some(uuid) = m.uuid else { continue };
+            let seen = feed.playing(uuid);
+            let age = m.age as f32;
+            let mut next = emotes::pose_playing(models.body_pose(m.id)).cloned();
+            match (seen, &mut next) {
+                (Some(seen), Some(p)) if Arc::ptr_eq(&p.item, &seen.item) => {
+                    if m.moved && p.stop.is_none() {
+                        p.stop = Some(age);
+                    }
+                }
+                (Some(seen), slot) if !m.moved => {
+                    let ticks = now.duration_since(seen.started).as_secs_f32() * 20.0;
+                    *slot = Some(horizon_cosmetics::Playing {
+                        item: seen.item,
+                        start: age - ticks,
+                        stop: None,
+                    });
+                }
+                (_, Some(p)) if p.stop.is_none() => p.stop = Some(age),
+                _ => {}
+            }
+            emotes::set_model_playing(models, m.id, next.filter(|p| p.at(age).is_some()));
+        }
+    }
+}
+
 impl Game<'_> {
-    /// Once a frame, before drawing: starts the service's client on first use and puts the
+    /// Hands the hooks what the game's settings and the player's emote say (allocating only when
+    /// the emote changes).
+    pub(super) fn cosmetics_say(&mut self) {
+        if !enabled() {
+            return;
+        }
+        let first = if self.cosmetics.local {
+            service(|s| s.said.first.is_none())
+                .then(|| self.owned_emotes().first().cloned())
+                .flatten()
+        } else {
+            None
+        };
+        let extras = &self.settings.extras;
+        let playing = self.cosmetics.emotes.sending();
+        let pull = self.cosmetics.emotes.pull();
+        service(|s| {
+            let said = &mut s.said;
+            said.mine = extras.cosmetics_mine;
+            said.listed = extras.horizon_listed;
+            said.others_shown = extras.effective_others() == Others::Shown;
+            said.others_hidden = extras.effective_others() == Others::Hidden;
+            said.marks = extras.horizon_marks;
+            said.solo = extras.cosmetics_solo;
+            said.pull = pull;
+            if said.playing.as_ref().map(|(id, l)| (id.as_str(), *l)) != playing {
+                said.playing = playing.map(|(id, l)| (id.to_owned(), l));
+            }
+            if first.is_some() {
+                said.first = first;
+            }
+        });
+    }
+
+    /// Once a frame, after the hooks: takes the service's client for drawing and puts the
    /// textures the last frame wanted into the atlas.
    pub(super) fn cosmetics_frame(&mut self) {
        if !enabled() {
            return;
        }
        let c = &mut self.cosmetics;
-        if c.client.is_none() {
-            let (client, local) = Cosmetics::client();
-            c.client = Some(client);
-            c.local = local;
-            // Others' emotes come from the service only (a local folder has no one playing).
-            if !local {
-                c.feed = Some(horizon_cosmetics::Feed::new(http()));
+        let owns = service(|s| {
+            if c.client.is_none() {
+                c.client = s.client.clone();
+                c.local = s.local;
            }
-        }
+            s.owner.owns
+        });
+        // Read every frame: the settings button shows it, and it is never saved.
+        self.settings.extras.cosmetics_owner = owns;
        c.frame.set(c.frame.get().wrapping_add(1));
        c.fx.get_mut().frame(c.frame.get());
-        // Item files from a folder (the art, the bench): shown as to an owner, nothing asked.
-        if c.local {
-            c.owner.owns = true;
-        } else {
-            // Whether the account owns a cosmetic: what the last run learnt, then the service.
-            let o = &mut c.owner;
-            if !o.started {
-                o.started = true;
-                o.owns = account()
-                    .is_some_and(|(_, uuid, home)| prefs::owned(&home, &uuid).unwrap_or(false));
-            }
-            if let Some(done) = o.asking.as_ref().and_then(|rx| rx.try_recv().ok()) {
-                o.asking = None;
-                match done {
-                    Ok(owns) => (o.owns, o.known, o.retry) = (owns, true, None),
-                    Err(_) => o.retry = backoff(o.retry),
-                }
-            }
-            // One sign-in at a time: Mojang keeps one joined server id per account.
-            let due = !o.known && o.retry.is_none_or(|(at, _)| Instant::now() >= at);
-            if due && o.asking.is_none() && c.mine.sending.is_none() && c.listed.sending.is_none() {
-                let (tx, rx) = channel();
-                o.asking = Some(rx);
-                std::thread::Builder::new()
-                    .name("Cosmetics account".into())
-                    .spawn(move || {
-                        let _ = tx.send(check_owner());
-                    })
-                    .ok();
-            }
-        }
-        // Read every frame: the settings button shows it, and it is never saved.
-        self.settings.extras.cosmetics_owner = c.owner.owns;
-        // Show my cosmetics: sent once per change of the wish, then retried until confirmed.
-        // Show me as a Horizon player: also said again every hour while on.
-        if !c.local {
-            let every = horizon_cosmetics::account::PRESENCE_EVERY;
-            c.mine.settle(None);
-            c.listed.settle(Some(every));
-            // One sign-in at a time, as for the ownership check above.
-            let busy =
-                c.owner.asking.is_some() || c.mine.sending.is_some() || c.listed.sending.is_some();
-            let extras = &self.settings.extras;
-            if let Some(done) = c
-                .emote_out
-                .sending
-                .as_ref()
-                .and_then(|rx| rx.try_recv().ok())
-            {
-                c.emote_out.sending = None;
-                match done {
-                    Ok(()) => c.emote_out.retry = None,
-                    Err(_) => {
-                        c.emote_out.retry = backoff(c.emote_out.retry);
-                        c.emote_out.sent = None;
-                    }
-                }
-            }
-            // My emote: only while I show myself as a Horizon player (playing one says so).
-            let playing = c.emotes.sending();
-            let looping = playing.as_ref().is_some_and(|(_, looping)| *looping);
-            let wish = playing.map(|(id, _)| id).filter(|_| extras.horizon_listed);
-            let o = &mut c.emote_out;
-            let changed = o.sent.as_ref() != Some(&wish);
-            let again = looping && o.again.is_some_and(|at| Instant::now() >= at);
-            let waited = o.retry.is_none_or(|(at, _)| Instant::now() >= at);
-            // Nothing sent yet and nothing playing: nothing to say (a failed send forgets what
-            // was sent: the service ends a one-shot by itself, a loop within a minute).
-            let quiet = wish.is_none() && o.sent.is_none();
-            let emote_due = !quiet && waited && (changed || again);
-            // One sign-in at a time, the emote's included.
-            if busy || o.sending.is_some() {
-            } else if emote_due {
-                o.sent = Some(wish.clone());
-                o.again = looping.then(|| Instant::now() + LOOP_AGAIN);
-                let (tx, rx) = channel();
-                o.sending = Some(rx);
-                let kept = o.kept.clone();
-                std::thread::Builder::new()
-                    .name("Cosmetics emote".into())
-                    .spawn(move || {
-                        let _ = tx.send(send_emote(&kept, wish.as_deref()));
-                    })
-                    .ok();
-            } else if c.mine.due(extras.cosmetics_mine) {
-                c.mine.start(extras.cosmetics_mine, send_mine);
-            } else if c.listed.due(extras.horizon_listed) {
-                c.listed.start(extras.horizon_listed, send_listed);
-            }
-        }
        let uploads = std::mem::take(&mut *c.uploads.borrow_mut());
        for item in uploads {
            let location = format!("cosmetics/{:x}", Arc::as_ptr(&item) as usize);
@@ -572,88 +872,6 @@ impl Game<'_> {
            .retain(|_, b| Arc::strong_count(&b.item) > 1);
    }

-    /// Once a tick: names the Horizon players in view to the emote feed and plays what it says
-    /// they play on their models; one that moved ends theirs here at once. Others' emotes show
-    /// with "Other players' cosmetics" on Shown only; otherwise nothing is asked.
-    pub(super) fn tick_others_emotes(&mut self) {
-        let shown = self.settings.extras.effective_others() == Others::Shown;
-        // Items from a folder (the art, the bench): every mannequin plays its first emote, again
-        // and again.
-        if self.cosmetics.local && shown {
-            let Some(first) = self.owned_emotes().first().cloned() else {
-                return;
-            };
-            for m in self.mobs.iter_mut() {
-                let age = m.age as f32;
-                if &*m.kind.id == "minecraft:mannequin"
-                    && emotes::playing(m).is_none_or(|p| p.at(age).is_none())
-                {
-                    let playing = horizon_cosmetics::Playing {
-                        item: first.clone(),
-                        // Out of step, so a crowd doesn't move as one.
-                        start: age - (m.id % 40) as f32,
-                        stop: None,
-                    };
-                    emotes::set_playing(m, Some(playing));
-                }
-            }
-            return;
-        }
-        let (Some(feed), Some(client)) = (&self.cosmetics.feed, &self.cosmetics.client) else {
-            return;
-        };
-        if !shown {
-            feed.ask([]);
-            for m in self.mobs.iter_mut() {
-                emotes::set_playing(m, None);
-            }
-            return;
-        }
-        let mut frame = client.frame();
-        let mut horizon = Vec::new();
-        for m in self.mobs.iter() {
-            if &*m.kind.id == "minecraft:player"
-                && let Some(uuid) = self.remote_player_uuid(m.id)
-                && frame.horizon(uuid)
-            {
-                horizon.push((m.id, uuid));
-            }
-        }
-        drop(frame);
-        feed.ask(horizon.iter().map(|(_, u)| *u));
-        let now = Instant::now();
-        for (id, uuid) in horizon {
-            let seen = feed.playing(uuid);
-            let Some(m) = self.mobs.iter_mut().find(|m| m.id == id) else {
-                continue;
-            };
-            let age = m.age as f32;
-            let moved = {
-                let (dx, dz) = (m.position.x - m.previous.x, m.position.z - m.previous.z);
-                dx * dx + dz * dz > 1e-4
-            };
-            let mut next = emotes::playing(m).cloned();
-            match (seen, &mut next) {
-                (Some(seen), Some(p)) if Arc::ptr_eq(&p.item, &seen.item) => {
-                    if moved && p.stop.is_none() {
-                        p.stop = Some(age);
-                    }
-                }
-                (Some(seen), slot) if !moved => {
-                    let ticks = now.duration_since(seen.started).as_secs_f32() * 20.0;
-                    *slot = Some(horizon_cosmetics::Playing {
-                        item: seen.item,
-                        start: age - ticks,
-                        stop: None,
-                    });
-                }
-                (_, Some(p)) if p.stop.is_none() => p.stop = Some(age),
-                _ => {}
-            }
-            emotes::set_playing(m, next.filter(|p| p.at(age).is_some()));
-        }
-    }
-
    /// Asks the service which emotes the account owns, for the wheel: when it opens, at most
    /// every 10 minutes (a folder's emotes need no asking; an offline account has none).
    pub(super) fn refresh_owned_emotes(&mut self) {
@@ -669,7 +887,7 @@ impl Game<'_> {
        }
        let (tx, rx) = channel();
        e.loading = Some(rx);
-        let kept = self.cosmetics.emote_out.kept.clone();
+        let kept = service(|s| s.emote_out.kept.clone());
        std::thread::Builder::new()
            .name("Cosmetics emotes owned".into())
            .spawn(move || {
@@ -678,81 +896,6 @@ impl Game<'_> {
            .ok();
    }

-    /// Items from a folder (`HORIZON_COSMETICS_LOCAL`): mannequins are dressed and marked too.
-    pub(super) fn cosmetics_local(&self) -> bool {
-        self.cosmetics.local
-    }
-
-    /// What goes by `m`'s name: Horizon's mark if they play Horizon (and the mark is on), the
-    /// name tag style they wear if cosmetics are shown for them (name tags only counts), and how
-    /// high what is drawn on their body gets (`body_top`). One look in the cache for all three.
-    pub(super) fn cosmetics_marks(&self, m: &Mob, own: bool) -> super::names::Marks {
-        let mut marks = super::names::Marks::default();
-        let extras = &self.settings.extras;
-        let styles = if own {
-            extras.cosmetics_mine
-        } else {
-            extras.effective_others() != Others::Hidden
-        };
-        if !(styles || extras.horizon_marks) {
-            return marks;
-        }
-        let (Some(client), Some(uuid)) = (&self.cosmetics.client, self.cosmetics_uuid(m, own))
-        else {
-            return marks;
-        };
-        let mut frame = client.frame();
-        marks.horizon = extras.horizon_marks && frame.horizon(uuid);
-        let worn = if styles { frame.worn(uuid) } else { None };
-        drop(frame);
-        if !horizon_client::mobs::trader::is_invisible(m) {
-            marks.top = body_top(extras, own, worn.as_ref(), |slot| covered(m, slot));
-        }
-        marks.style = worn.and_then(|w| self.cosmetics_tag(&w));
-        marks
-    }
-
-    /// Those of `uuids` who play Horizon, with the mark on (the player list): one look each.
-    pub(super) fn horizon_players(
-        &self,
-        uuids: impl Iterator<Item = u128>,
-    ) -> std::collections::HashSet<u128> {
-        match &self.cosmetics.client {
-            Some(c) if self.settings.extras.horizon_marks => {
-                let mut frame = c.frame();
-                uuids.filter(|u| frame.horizon(*u)).collect()
-            }
-            _ => Default::default(),
-        }
-    }
-
-    /// The name tag style in `worn`: its badge's place in the atlas and its line's colour. None
-    /// until the badge is in the atlas.
-    fn cosmetics_tag(&self, worn: &horizon_cosmetics::Worn) -> Option<super::names::TagStyle> {
-        let item = worn.iter().find(|i| i.slot == Slot::NameTag)?;
-        let [r, g, b] = item.tag?.line;
-        let frame = self.cosmetics.frame.get();
-        let mut baked = self.cosmetics.baked.borrow_mut();
-        let entry = baked
-            .entry(Arc::as_ptr(item) as usize)
-            .or_insert_with(|| Baked::new(item, frame));
-        let Some(slot) = self.gui.atlas.sprites.get(&entry.location) else {
-            self.cosmetics.uploads.borrow_mut().push(item.clone());
-            return None;
-        };
-        if entry.marked.replace(frame) != frame {
-            self.skin_downloads.borrow_mut().drawn(&entry.location);
-        }
-        // The mark sits in the slot's top left corner.
-        let mut mark = *slot;
-        mark.u1 = mark.u0 + (slot.u1 - slot.u0) * item.texture.width as f32 / 64.0;
-        mark.v1 = mark.v0 + (slot.v1 - slot.v0) * item.texture.height as f32 / 64.0;
-        Some(super::names::TagStyle {
-            mark,
-            line: u32::from_be_bytes([0, r, g, b]),
-        })
-    }
-
    /// What `m` wears, if cosmetics are shown for it: `own` for the player's own model.
    fn worn(&self, m: &Mob, own: bool) -> Option<horizon_cosmetics::Worn> {
        let client = self.cosmetics.client.as_ref()?;
@@ -844,7 +987,7 @@ impl Game<'_> {
                }
                continue;
            }
-            if emoting.is_none() && covered(m, item.slot) {
+            if emoting.is_none() && covered(super::player_hooks::gear(m), item.slot) {
                continue;
            }
            let Some((models, uv)) = self.cosmetics_baked(item) else {
@@ -962,7 +1105,7 @@ impl Game<'_> {
 mod tests {
    use super::*;
    use horizon_client::extras::Extras;
-    use std::sync::Mutex;
+    use horizon_client::mobs::anim::BodyPose;

    /// A name tag style with a 1×1 mark.
    const TAG: &str = r##"{"format": 1, "id": "tag", "slot": "name_tag", "parts": [],
@@ -1150,13 +1293,18 @@ mod tests {
        let (short, long) = (Duration::from_millis(300), Duration::from_secs(10));
        let top_of = |extras: &Extras, patience| {
            let (worn, _) = other_player_from(Service(Arc::default(), both), extras, patience);
-            body_top(extras, false, worn.as_ref(), |_| false)
+            body_top(extras.effective_others(), false, worn.as_ref(), |_| false)
        };
        // No cosmetics drawn on the body (a name tag style only): vanilla's height exactly.
        let (worn, _) = other_player(&shown, long);
        assert!(worn.is_some());
        assert_eq!(
-            tag(body_top(&shown, false, worn.as_ref(), |_| false)),
+            tag(body_top(
+                shown.effective_others(),
+                false,
+                worn.as_ref(),
+                |_| false
+            )),
            VANILLA
        );
        // A small hat under the tag: vanilla's height too.
@@ -1170,7 +1318,9 @@ mod tests {
        );
        // A helmet over it: vanilla's height.
        let (worn, _) = other_player_from(Service(Arc::default(), both), &shown, long);
-        let helmet = body_top(&shown, false, worn.as_ref(), |slot| slot == Slot::Head);
+        let helmet = body_top(shown.effective_others(), false, worn.as_ref(), |slot| {
+            slot == Slot::Head
+        });
        assert_eq!(tag(helmet), VANILLA);
        // Others' cosmetics on name tags only, or hidden: nothing on the body, vanilla's height.
        for others in [Others::NameTags, Others::Hidden] {
@@ -1186,4 +1336,66 @@ mod tests {
            assert_eq!(tag(top_of(&extras, patience)), VANILLA, "{others:?}");
        }
    }
+
+    /// Player models as the hooks see them, with the pose laid over each.
+    struct View(Vec<(PlayerModel, Option<Arc<dyn BodyPose>>)>);
+
+    impl PlayerModels for View {
+        fn connection(&self) -> u64 {
+            1
+        }
+        fn for_each(&self, f: &mut dyn FnMut(PlayerModel)) {
+            self.0.iter().for_each(|(m, _)| f(*m));
+        }
+        fn body_pose(&self, id: u32) -> Option<&Arc<dyn BodyPose>> {
+            self.0.iter().find(|(m, _)| m.id == id)?.1.as_ref()
+        }
+        fn set_body_pose(&mut self, id: u32, pose: Option<Arc<dyn BodyPose>>) {
+            if let Some((_, p)) = self.0.iter_mut().find(|(m, _)| m.id == id) {
+                *p = pose;
+            }
+        }
+    }
+
+    #[test]
+    fn with_a_folder_mannequins_play_its_first_emote_out_of_step_and_players_do_not() {
+        let item = Arc::new(
+            Item::parse(
+                br#"{"format": 1, "id": "up", "slot": "emote", "parts": [],
+                    "emote": {"length": 20, "blend": 0, "tracks": [
+                      {"part": "right_arm", "keys": [{"t": 10, "rotation": [0, 0, 90]}]}]}}"#,
+            )
+            .unwrap(),
+        );
+        let mut service = Seat {
+            local: true,
+            said: Said {
+                others_shown: true,
+                first: Some(item.clone()),
+                ..Said::default()
+            },
+            ..Seat::default()
+        };
+        let model = |id, kind, uuid| (PlayerModel::new(id, kind, uuid, 50, false), None);
+        let mut view = View(vec![
+            model(1, Kind::Own, None),
+            model(41, Kind::Mannequin, None),
+            model(2, Kind::Player, Some(7)),
+        ]);
+        service.tick(&mut view);
+        let playing = emotes::pose_playing(view.0[1].1.as_ref()).expect("the mannequin plays");
+        assert!(Arc::ptr_eq(&playing.item, &item));
+        // Out of step by its id: 50 - 41 % 40.
+        assert_eq!(playing.start, 49.0);
+        assert!(view.0[0].1.is_none() && view.0[2].1.is_none());
+        // Still playing: the same pose stays.
+        let first = view.0[1].1.clone().unwrap();
+        service.tick(&mut view);
+        assert!(Arc::ptr_eq(&first, view.0[1].1.as_ref().unwrap()));
+        // Others' cosmetics not shown: a new mannequin plays nothing.
+        service.said.others_shown = false;
+        view.0.push(model(3, Kind::Mannequin, None));
+        service.tick(&mut view);
+        assert!(view.0[3].1.is_none());
+    }
 }
@@ -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 +65,48 @@ 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 emote `m` plays, if any.
+pub(in crate::game) fn playing(m: &Mob) -> Option<&Playing> {
+    pose_playing(m.emote.as_ref())
+}
+
+/// 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 +260,7 @@ 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 +281,6 @@ 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)
    }
 }

@@ -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