# Module (asset type) A module is a reusable, stateless (or globally-stateful) Luau library that other code pulls in with `require()`. Modules are the unit of factored-out logic in a world: helpers, math libraries, format parsers, registries, shared algorithms. ## When to use one - You have logic you want to share across multiple components, services, scenes, or tools. - You have a registry, lookup table, or shared cache that callers all read from / write to. - You want a stable API surface (`M.fn`) other code can depend on. If the logic is bound to one entity, use a `.component`. If you want a named UI of fields rather than functions, use a `.preset`. ## Where it lives - Source: `/zero/source/.../<name>.module/` - Identity: the source path with `/` written as `.` and each segment's type suffix dropped — `/zero/source/demo/beats.module` is `demo.beats`, and `/zero/source/kit.package/beats.module` is `kit.beats`, the container's name kept and its `.package` suffix gone. `asset.create` returns this string, `asset.resolve(...).identity` reads it back, and the `require` forms below write it as `<identity>`. - Folder shape: - `init.luau` (or `init.lua`) — module body. **Required.** Returns a table (conventionally named `M`). - `README.md` — instance-level documentation. **Required.** - `.metadata` — agent-editable tags + free-form fields. **Required.** ## How to create one ```luau asset.create("module", "<name>") -- Creates: /zero/source/<name>.module/ -- init.luau (canonical `local M = {} … return M`) -- README.md (instance README template) -- `folder` places it in a subfolder of /source, and that subfolder -- leads the identity: `{ folder = "lib" }` produces `lib.<name>`. -- `into` authors it inside a resolved container (a package, a toolbox), -- whose own identity leads the same way: asset.create("module", "<name>", { folder = "lib" }) asset.create("module", "<name>", { into = asset.resolve("myPkg.package") }) ``` ## How it operates 1. **Registration.** Writing `init.luau` into a `.module/` folder indexes the asset and registers the module path with the resolver. 2. **Loading.** The first `require("<identity>")` runs the file's body and caches the returned table. Subsequent requires from anywhere return the **same table** — this is the shared-state lever for "module-local" registries. 3. **Hot reload.** Editing the file re-runs the module body and folds what it returns into the table already loaded, so that table keeps its identity: a caller that captured it with `require` reads the new source's functions and values through the reference it already holds, and a later `require` returns that same table. A key the new source drops goes away; a key something set at runtime stays. The body's own `local`s start again from their initial values, so state that must outlive an edit lives in `modules.state()` (`guides { path: "core/scripting-and-tasks" }`). 4. **Identity resolution.** A module is reached by its `<identity>`, and where the caller lives decides which spelling of it resolves. For a module in a **world**, from a caller in that same world — another module, a component, a scene entrypoint, or an `execute` chunk: - `require("<identity>")` — the identity on its own, resolved against the caller's own root. It carries every folder segment, so a module created with `{ folder = "demo" }` is `require("demo.beats")`. - `require("@root::<identity>")` — the same root-relative resolution, written out. - `require(".sibling")` — a module in the same folder, by its bare name; `..name` steps up one folder, `...name` two. Logs, stack traces and hot-reload notices name that same module `@local.source.<identity>` — its key under the world source root. The `<identity>` tail of that key is the form above, so a trace reading `@local.source.demo.beats` is `require("demo.beats")`. For a module in a **library** — content under `/zero/source/libs/@<lib>/` — `@<lib>::` addresses that library's root from anywhere: `require("@builtin::modules.transform")`. Mounting a world as a library moves its files under such a root and flips the caller root to `@<lib>::`, which is what keeps the root-relative forms above resolving across the move. ## Discovery - `asset.list("module")` — every registered module. - `asset.inspect("<name>")` — public functions, source path, this type README. - `ls /zero/source/<name>.module` lists the files the folder holds. ## Authoring conventions - Return a single `M` table from `init.luau`. Top-level statements with side effects run on first require — useful for one-time initialization, dangerous if they touch the engine before it's ready. - Write exported functions as `typed function`, not `function`: the argument types are enforced at the call and the checker knows the signature, so a caller's mistake is reported where they made it. - Annotate exported functions with `--!desc` / `--!arg` / `--!return` / `--!example` so the LSP, `tools.list`, and `asset.inspect` surface them. A function with no `--!desc` is reachable only by someone already reading this file. - Declare a VALUE with `Field.<kind>(default, mode, description)`, and a table whose members are reached through a metatable with `--!members <TypeName>` — the latter gives the surface its accepted member set, its type, and its documentation from one table. See `guides { path: "core/authoring" }` for all four rules and `modules/api/engine/entity.module/members.module` for a worked member table. - Keep module state in module-local upvalues or in `modules.state()`. Globals leak across reloads. Module-locals start again from their initial values with each hot reload; the table `modules.state()` returns is the same table on both sides of every reload. - Prefer focused modules over kitchen-sink modules. If two halves of a module have no shared state, split them. ## Common pitfalls - **Cyclic requires.** A `require` chain that loops will return the partial table (the half built before the cycle was detected). Design for one-way dependencies. - **Engine-time side effects.** Don't `entity.spawn` at module top-level — the engine may not be ready. Expose an `M.init` and call it from a scene entrypoint. - **Hot-reload + module-local cache.** A module that caches expensive computation in upvalues loses that cache on reload — fine for dev, but be aware in performance work. - **`init.lua` vs `init.luau`.** Either works, `.luau` is canonical. - **Writing one while play runs.** A `/source` write made while play is running lands on the play shadow, and a guarded play-exit discards it unless it is kept. One `.module` write shadows `init.luau`, the `README.md` and the `.metadata` together. `vfs.write(path, bytes, { durable = true })` skips the shadow, and `vfs.promotePlayShadow` keeps what is already on it — the `core/vfs` guide has the model and what each route costs. ## Related types - `.component` — for entity-bound state + lifecycle hooks. - `.service` — generates content you don't have yet (a mesh, sound, texture, …) via a metered provider. - `.tool` — for a single agent-callable function with a YAML schema. - `.package` — to group several modules + components + scenes into one shippable folder. ## In the Inspector Exports: what the module exports (name, kind, signature), parsed from its source without running it, with **Check** (the LSP's diagnostics for its entry file) and **Open**.

# marquee_overlay A screen-space translucent rectangle with a 1px border, drawn while a viewport rubber-band (marquee) selection is dragging and hidden otherwise. It owns one dedicated UI screen tagged `editor`, so it rides the `EditorUI` render layer and the editor's F1 chrome toggle alongside the rest of the editor overlays. `viewport_select` drives it. ## Exports - `M.show(ax, ay, bx, by)` — show the band filling the rectangle spanned by the two corners, given in UI-logical points (the `ui.screenSize()` space). Corners may be passed in any order. - `M.hide()` — hide the band. Safe to call when nothing is shown. ## Notes - Callers work in viewport pixels; convert to UI-logical points (multiply by `ui.screenSize().width / viewport.w` and the height ratio) before calling `show`, since absolute `left`/`top`/`width`/`height` resolve in the logical space, not render pixels. - Coordinates are rounded to whole points so a value in the open `(0, 1)` range is never mistaken for a viewport-axis fraction by the size decoder.

# editor_observe What an editor action committed, and why it committed less than it was asked for. Every editor action — a gizmo drag, a delete, a duplicate, a command dispatch, a selection gesture — closes by publishing one record here, and returns that same record to its caller. Nothing is measured per frame: a record is written where the work happens and read lazily. ```lua local Obs = require("@builtin::modules.api.editor.editor_observe") Obs.observe() -- the whole document: last of each kind, history, counts Obs.last() -- the most recent action of any kind Obs.last("drag") -- the most recent drag Obs.history() -- every retained action, oldest first ``` The same reading is a tool: `tools.use("editor", "observe")`. ## What every record carries - `action` — `drag`, `grab`, `delete`, `duplicate`, `command` or `select`. - `outcome` — `committed`, `partial`, `refused`, `cancelled` or `noop`. - `reason` — the nearest cause, from the closed set below, when the outcome is anything but a clean commit. - `detail` — the engine's own words for that cause. - `entities` — one row per entity the action touched or tried to, each with `before`, `requested` and `after`, and its own `reason` when it is not a clean commit. - `committed` / `changed` / `refused` — how many rows fall in each. - `seq`, `atMs`, `durationMs` — which action this is and how long it was open. ## The reason set `selectionEmpty`, `entityMissing`, `writeRefused`, `writeDiverged`, `pivotLost`, `userCancelled`, `commitFailed`, `duplicateRefused`, `despawnRefused`, `unchanged`, `commandMissing`, `commandDisabled`, `predicateRaised`, `bodyRaised`, `hitNothing`, `pointerBlocked`. `Obs.REASONS` maps each to its one-line meaning, so a caller can enumerate the set rather than guess at it. ## A drag that moved less than asked The drag record separates the three quantities that are usually conflated: - `pointerAsked` — what the pointer's position asked for, before snapping. - `applied` — what the gizmo handed the engine, after snapping. `snapping` and `snapIncrement` say why the two differ. - each entity's `after` — the transform the engine **holds**, read back from the engine rather than recomputed from the drag's own arithmetic. An entity whose `after` differs from its `requested` reads `writeDiverged`; one whose write raised reads `writeRefused` with the message; one despawned mid-drag reads `entityMissing`. A drag that ended on Esc reads `cancelled` / `userCancelled`, and one whose selection emptied under it reads `cancelled` / `pivotLost` — three terminal states a single "the object did not move" cannot tell apart. ## A drag that never began A press that lands on a handle and starts no drag publishes a `grab` record instead — `Obs.last("grab")`, or `Gizmo.lastGrab()`. `pointerBlocked` says the UI layer held pointer focus, so the press never reached the handle. A press away from every handle is a selection click rather than a grab, and records nothing. One record per press: a frame that ticks the gizmo more than once reports the press once. `unit` names what `pointerAsked` and `applied` are measured in: `metres` for a translate or plane drag (a world-space `{x,y,z}` delta), `radians` for a rotate (`{radians}`), `factor` for a scale (`{factor}`). ## Per-frame cost The editor's own per-frame work is named in the profiler rather than pooled into `lua_update`: `script.editor.gizmo.tick`, `script.editor.viewport.select`, `script.editor.selection.highlight`, and `script.editor.panel.<id>` for each dock panel's rebuild. Read them with `profiler.stats()`.

# editorSelection Named selection scopes for the editor. A scope is an independently tracked, ordered set of typed refs plus a primary (the last ref added or clicked). Distinct scopes never clobber each other, so viewport, outliner, inspector and asset browser share one answer to "what is selected" per kind. A ref is `{ kind: string, id: string }` — a stable id, never a display string, so rename/move never invalidates a selection. ## Exports - `M.scope(name) -> Scope` — get/create a named scope handle. - `M.set(scope, refs)` — replace refs in order; primary becomes the last. - `M.get(scope) -> { Ref }` — refs in click order (fresh array). - `M.primary(scope) -> Ref?` — last-clicked ref, or nil. - `M.clear(scope)` — empty a scope. - `M.toggle(scope, ref)` — add if absent, remove if present. - `M.add(scope, refs)` — add each ref not already present; primary becomes the last added. - `M.remove(scope, refs)` — remove each of `refs`; primary becomes the last remaining or nil. - `M.contains(scope, ref) -> boolean` — membership by `(kind, id)`. - `M.count(scope) -> number` — the scope's selection size. - `M.subscribe(scope, fn) -> handle` / `M.unsubscribe(scope, handle) -> boolean`. - `M.context() -> { scope, refs, primary }` — last-focused scope, for command ctx. ## Usage ```luau local Selection = require("@builtin::modules.api.editor.selection") local scope = Selection.scope("entity") Selection.set(scope, { { kind = "entity", id = "player_1" } }) Selection.subscribe(scope, function() refreshInspector() end) ``` ## Notes - State lives in a fixed `_G` slot, seeded pre-seal by the boot chain (`prelude.luau`); it survives hot-reload and edit↔play flips. Mutations after boot write into nested tables only. - `set` / `toggle` / `clear` mark their scope as last-focused, which drives `context()` and therefore which scope commands act on. - The service holds the editor's selection state in Luau. Refs handed back by `get` / `primary` / `context` are copies, so a caller can hold or mutate them without touching internal state.

# picking Mouse/pointer picking helpers. Wraps the engine-provided `getPointerHitTable()` and `getLookHitTable()` globals into decoded Lua tables and exposes small extractors for the entity id / name fields callers reach for most often. ## Exports - `M.getHit() -> Hit?` — current pointer hit, or `nil` when none. - `M.getLook() -> Hit?` — current look-at (camera-center) hit, or `nil`. - `M.hoveredEntityId(hit: Hit?) -> string?` — extract `entity_id` from a hit. - `M.lookedEntityId(hit: Hit?) -> string?` — same shape, semantic mirror of `hoveredEntityId`. - `M.hoveredName(hit: Hit?) -> string?` — extract `name` from a hit. Types: - `Hit = { entity_id: string?, name: string?, [string]: any }` — the engine-emitted hit table; carries additional fields beyond those typed here. ## Usage ```luau local Picking = require("@builtin::modules.picking") local hit = Picking.getHit() local id = Picking.hoveredEntityId(hit) if id then print("hovering over", id) end ``` ## Notes - Returns `nil` (not `false`) when the engine globals are absent — call sites can branch on `if hit then ...`. - The extractors accept `nil` so callers can chain `Picking.hoveredEntityId(Picking.getHit())` without a manual guard. - Pure read-side helpers — no state, no side effects.

# gizmo Transform gizmo — draggable translate/rotate/scale handles at the selection pivot. Handles draw through a debugViz provider; hit-testing and dragging use `gizmo_math` against the cursor's `screenToRay`. Each drag edits every selected entity through the entity proxy transform setters and is wrapped in a multiplayer undo operation, so a whole drag reverts as a single Ctrl+Z. The mode (translate / rotate / scale), the local/world space toggle, and the active drag live in module state; the editor scene entrypoint calls `tick` every frame and switches mode from the tool hotkeys. Handles size themselves to stay a roughly constant on-screen length, and holding the snap modifier quantizes translation to a grid, rotation to angle steps, and scale to fixed steps.

# zinput zinput is the engine's Luau-side input framework and the **only** public Luau input API. It sits on top of the internal `__zero_input.*` FFI (snapshot, events, frameId, pointer-lock, simulate\*) and builds the control model above it in pure Luau: control assets grouped into maps, the live set of activated maps and its per-frame dispatch, per-device-class binding evaluation, the on-screen touch overlay, gesture recognisers, and the tick coordinator that advances all of it. The top-level module re-exports every submodule under a single table and owns the tick coordinator (`Zin.tick`) plus the unified handle namespace for `Zin.disconnect`. ## The control model A control is a `<name>.inputBinding/` folder inside a `<name>.inputMap/` folder. It carries a `label`, a `kind` (`button` / `axis1` / `axis2`), and a binding for each of the three device classes — `kbm`, `gamepad`, `touch`. A class set to `false` is a deliberate refusal. Nothing is live until something activates a map. A world activates the map it needs and subscribes to the controls it uses: ```luau public = { inputMap = Field.assetRef("inputMap", "@builtin::inputMaps.default", NoSync, "The controls this component reads."), speed = Field.number(5, NoSync, "World units per second at full deflection."), jumps = Field.number(0, NoSync, "How many times the jump control was pressed."), } local controls function awake() controls = public.inputMap:activate() controls.move:onInput(function(v, dt, active) if not active then return end local p = public.entity.position local step = public.speed * dt public.entity.position = { p.x + v.x * step, p.y, p.z - v.y * step } end) controls.jump:onPressed(function() public.jumps += 1 end) end function onDestroy() public.inputMap:deactivate(controls) end ``` What `activate` returned is this holder's claim on the map, and handing it back to `deactivate` disconnects the subscriptions made through it while the map stays live for whoever else holds it. Every activation reads the map's binding children again, so a control edited since it came up reaches the running set and the holders already standing on it. Several maps are live at once and compose: the player's surface is the union of them, so picking up a gun adds Fire beside the movement stick and dropping it takes away Fire alone. A map declares the `group` its controls belong to and the groups it `suppresses` while live, which is how a car stands walking down without owning the walk map. `Zin.scheme` holds the live set and runs the dispatch. `man topics/input` is the full walkthrough. ## Exports Subsystems (re-exported from the corresponding submodule): - `M.scheme` — the live set of activated maps and their per-frame dispatch. - `M.bindings` — binding constructors, evaluators, and the legend formatter. - `M.state` — per-frame snapshot reads plus held-time and synthetic repeat. - `M.events` — frame-event readers and `on`/`off` edge subscriptions. - `M.input` — `onBegan` / `onEnded` / `onChanged` / `onTextInput` listeners and `lastInputType()`. - `M.context` — the input context stack. - `M.chords` — sequence and simultaneous recognisers. - `M.gestures` — tap / double-tap / long-press / swipe / pinch / pan recognisers. - `M.touch` — per-finger contacts and `touch.*` listeners. - `M.surface` — touch-vs-kbm device-class classification. - `M.gamepad` — connected pads, family, and button legends. - `M.virtual` — the per-tick virtual-control store on-screen controls write. - `M.touchControls` — the on-screen touch overlay (stick, drag-look zone, buttons) and the API that adds a control while a world runs. - `M.emulation` — the map-driven key-emulation floor. - `M.pointer` — pointer-lock mutations. - `M.back`: Back, claims a world holds while Back means something to it, and `press` to issue one. The engine routes each press to the topmost dismissible overlay, else the most recent claim, else the platform's own default (an Android app moves to the background). - `M.test` — synchronous test-input helpers. - `M.controllers` — `free` / `orbit` / `fps` controller factories. - `M.profile` — binding profiles, saved as JSON and loadable from `@builtin::profiles.<name>`. - `M.rebind` — interactive binding-capture sessions. - `M.conflicts` — the binding-collision reverse index. - `M.autoTick` — the opt-in per-frame tick worker. - `M.utils` — pure helpers. - `M.actions` / `M.axes` / `M.map` — the name-registered action, axis and map registry. A control asset replaced them; each carries its own `--!deprecated` message naming the replacement. Tick coordinator: - `M.tick(dt: number?)` — advance every stateful subsystem. - `M.lastTickAt() -> number` / `M.lastTickFrameId() -> number` — test/debug accessors. - `M._resetTickGuard()` / `M._resetLiveArmed()` — test-only. Handles: - `M.disconnect(handle: number) -> boolean` — accepts any Zin handle (input listener OR action handler) and routes to the right `disconnect`. Constants: - `M.VERSION` — the library version string. - `M.SPEC` — the VFS path of the architecture spec. - `M.ROADMAP` — the VFS path of the roadmap document. ## Raw state `Zin.state` and `Zin.events` are the snapshot and event layer that bindings evaluate against — the layer the emulation floor, rebind capture, and dev tooling operate on directly. Gameplay code subscribes to controls; polling `Zin.state.keyDown` from a world makes that world keyboard-only and draws the `engine-raw-key-poll` diagnostic at author time. ## Notes - `Zin.tick(dt)` is the single hub that advances every stateful subsystem each frame. Stateless features (state / events / utils / bindings / context) work without ticking; the live binding dispatch, axes, chords, subscriptions, held-time, repeat, and rebind are dormant until something ticks. - The first real input read arms the input system on its own: it starts `Zin.autoTick`, so dispatch, the touch overlay and the emulation floor advance with no host component and no explicit tick call. A host script component can still call `Zin.tick(dt)` from its `update(dt)` hook, and `Zin.autoTick.start()` remains available directly; both stay idempotent alongside the self-arming path. `Zin.test` engagement suppresses the arming so suites keep explicit control over tick cadence. - Same-frame re-tick dedup: `__zero_input.events()` is non-draining, so running the observe-and-dispatch pipeline twice in one engine frame would double-fire subscribers. The frame-id guard in `M.tick` and the autoTick worker keeps this from happening. - The handle namespace is unified: every handle from `Zin.input.on*` and `Zin.actions.bind` is drawn from a single counter, and `Zin.disconnect` routes any of them to the correct `disconnect`. `Zin.input.disconnect` and `Zin.actions.disconnect` are also wired to the unified dispatcher. - Library users can either grab the whole table (`require("@builtin::modules.zinput")`) or pull one submodule (`require("@builtin::modules.zinput.state")`). - `__zero_input` is an internal namespace — reachable from Luau but hidden from `/docs/api/`; production game code goes through Zin.

# assetType (asset type) The `assetType` is the **type of types** — the meta-type that every `<typename>.assetType/` folder is an instance of, including itself. A `<typename>.assetType/` folder declares a new asset type called `<typename>`: its on-disk shape, its identity rule, and the structural contract instances of the type must satisfy. This type is self-hosting. `assetType.assetType/` conforms to its own schema — a `type.yaml` plus a `README.md` — so the type system is defined in terms of itself rather than a hidden engine special-case (the same way a C compiler is written in C). Every asset in the engine, including each `.assetType` definition, now resolves to a registered assetType: a `.material` resolves to `material.assetType`, and `material.assetType` resolves to `assetType.assetType`, which resolves to itself. ## Why it exists Assets used to be mapped to their type *implicitly*, by matching the folder suffix against a name-keyed registry. That match carried no stored link: nothing on a `Foo.material` recorded *which* `material.assetType` it was written against, so two worlds shipping a same-named type could silently disagree. Making `assetType` a real, resolvable asset closes that gap — the link from an asset to its type is now an explicit reference pinned in the asset's `.refs` sidecar (`via: "asset_type"`), exactly like every other dependency. ## Where it lives - Source: `/zero/source/.../<typename>.assetType/` - Identity: `<typename>` (the `.assetType` suffix strips from the identity; the folder retains the suffix on disk). - Folder shape: - `type.yaml` — the structural spec the validator reads. **Required.** - `README.md` — type-level documentation. **Required.** - `about.yaml` — three short plain-language texts saying what the type is for (see "Say what your type is for" below). Every built-in type ships one. - `behavior.luau` — optional behavior/scaffolding module. - `template/` — optional canonical placeholder body the templater copies into a new asset of the type. - `<name>.module/` — optional shared code the type ships to **every instance** of it, conventionally `shared.module/` (see below). ## Shared code its instances reach (`asset.containing` + `.modules`) A type ships code every instance of it uses by declaring the modules in its own `behavior.luau`, as a map of tracked `require`s: ```luau -- inside <typename>.assetType/behavior.luau M.modules = { shared = require(".shared") } -- the sibling shared.module/ ``` An instance reaches it with one location-independent line: ```luau -- inside any foo.<typename>/init.luau local api = asset.containing(__FILE__).modules.shared ``` `__FILE__` is the chunk's own VFS path; `asset.containing` resolves the calling asset, and `.modules.<name>` follows the instance's pinned `typeRef` (the type's **guid**, recorded in the instance's `.refs` as `via = "asset_type"`) to the module its type declares. Because resolution follows that link rather than a category name, the same line in an instance of a different type resolves to that type's module, and identically-named modules in two types never collide. `asset.typeRef(target)` reads that guid for any target; `asset.resolve(asset.typeRef(target))` gives the full `AssetRef<assetType>`. See `assetTypes/README.md` § "Shared code: type-owned modules" for the full mechanism. ## How to create one Authoring a new asset type is just creating a `<typename>.assetType/` folder under `/zero/source/`. The engine registers `<typename>` as a category **the moment the folder is written** — no engine restart, no Rust change, and it works for built-in (`@builtin/assetTypes/`) and user-defined types identically. Once `<typename>` is registered, `<name>.<typename>/` folders are recognised as assets of that type and resolve their `asset_type` link back to this definition. Creating a `<name>.<typename>/` folder *before* its `<typename>.assetType/` exists fails fast: the suffix has no registered type, so the folder can't be a valid asset. Author the type first. ## Say what your type is for (`about.yaml`) Every type carries a small `about.yaml` beside its `type.yaml`, and the README you write for the type documents how to author an asset of it. Both are required, and both are meant to be written as you make the type, while you know what it is for. `about.yaml` answers three questions in plain words, one key each: ```yaml intent: "Sets the typeface of the text in your game: UI, labels, signs and 3D lettering." function: "A font, from a TTF, OTF or WOFF file, made available to all of Zero's text, including 3D text." usage: "You choose it by name for your UI or your text, and the text appears in that typeface." ``` - **`intent`** is what the type is for in someone's game. Name the whole range of things it covers, in the words a game maker would use for them. - **`function`** is how it works today: what an asset of the type is made of and what the engine does with it. - **`usage`** is what a person or an agent does with one: how they pick it, place it, call it, or hand it to something else. A few habits keep it useful. Write about the type as a whole, so the text holds for every asset of it, and leave out any one asset's name. Say what the type does right now. Stay with words a game maker would say, and mention a file name or a call only where a game maker would know it. The limits are in bytes: `intent` 800, `function` 1500, `usage` 1200. Each is generous, and a few sentences usually say it. Why bother: agents working in a world read these three texts to learn what your type is for, so they reach for it when it fits and use it the way you meant. People searching find the type by what they want to make, and the three texts let them tell at a glance whether it is the one they need. `asset.create("assetType", name)` scaffolds the file with all three keys, and a README whose first paragraph is a `[[describe]]` note. Each value starts with `[[describe]]` followed by a note on what to write; replace the whole value with your own words. A value or a README line that still starts with `[[describe]]` counts as not written yet, which the push's check of each asset it carries against its type reports, naming the file. A type you leave as it was is not asked, so older types stand. Many types at once, or one you would rather not write by hand: `services describe` lists the types that lack these texts and what filling them costs, and `{ mode = "all" }` writes them into the same files, where you edit them like anything else you wrote. Where the texts show up: `asset.inspect("<typename>", "assetType")` returns them as `detail.about`, `assetTypeRef:getAbout()` returns them as a table with the keys `intent`, `function` and `usage`, the type's `types/<typename>` guide page ends with an "About this type" section holding them, and the Inspector's Type section lists them at the top. The guide page is this README plus that section, so a README that explains the type well and an `about.yaml` that says what it is for read well together. ## Ask your assets to say what they are A type can ask each of its assets to carry a description: a file, written by the author or generated, that says what that asset is and what it is for. The people and agents who find an asset read it to decide whether it fits, and the author knows what it is for at the moment of making it. **1. Declare the file with a `described` check.** This is the whole requirement: ```yaml files: required: - path: "README.md" # any file name works kind: "file" content: - { check: "described", message: "Say what this widget is for and where it goes." } ``` With that in place: - An asset whose file is missing, empty, or still has a line starting with `[[describe]]` does not meet the type's requirements. `asset.validate` names it, `zm status` and `world.publishBlockers()` list it, and a push that carries it is refused with `message`. - `services describe` finds it (`mode = "find"` lists it and the price) and can write the description for it (`mode = "all"`). It writes only this file. For a YAML file that holds several texts, name the keys and their limits in bytes, the way this type does for `about.yaml`: ```yaml content: - check: "described" keys: - { key: "intent", max_bytes: 800 } - { key: "usage", max_bytes: 1200 } message: "Write intent and usage." ``` `headings` names sections a Markdown file must have. `assetTypes/README.md` has the full check. **2. Optionally, steer what gets generated with a `describe:` block:** ```yaml describe: guidance: "Say what the widget shows, what input it reacts to, and where it fits in a UI." examples: - "<identity of an asset of this type whose description reads well>" ``` `guidance` says what a description of your type covers, and `examples` names assets whose descriptions show the shape you want. Without the block, generation still works from the general describing guide and the check's `message`. An example is an asset of your type in the library whose description is a true, written one, never a scaffold's placeholder, and never the asset being described. When the library has none, leave `examples` empty rather than name one that is not. A type whose assets the model cannot perceive (a sound it cannot hear, a motion it cannot see) says so in `guidance`: the description comes only from what the asset's own files state, such as its name and the `.metadata` where a generation service records the prompt that made it, and when they state nothing the model answers `cannot` with that reason. `services describe` then fails that one asset with the reason and leaves its file as it was. **3. Start the file unwritten in your template.** Put a heading and one line that starts with `[[describe]]` and a short note on what to write, in `template/<file>`, so a new asset starts unwritten rather than with text that only looks written. Do not put example content in it: every new asset carries the template verbatim, and the same text on many assets makes them impossible to tell apart in search. Types whose assets say what they are through their own content (a mesh, a texture, a sound) leave this out: declare nothing and nothing is asked. ## The `behavior.luau` contract `behavior.luau` is the type's code. It returns ONE table, and the keys below are the ones the framework reads off it for EVERY type — the surface you get by declaring them. Anything else on the table is your own: reachable by name through `require("@builtin::assetTypes.assetType.shared.ref").loadTypeModule("<typename>")` for a system that knows your type (`computeShader` publishes `dispatchKey` that way), and never called by the framework. ```luau local M = {} M.ref = { ... } -- methods on every AssetRef of this type M.modules = { ... } -- shared code the instances reach M.global = {} -- reserved key; ship the empty table function M.onCreate(name, opts) ... end return M ``` ### The tables | Key | Shape | What the engine does with it | |-----|-------|------------------------------| | `M.ref` | `{ [name] = function(self, ...) }` | Every function becomes a method on every `AssetRef` of this type: `ref:name(...)`, with `self` the ref. This is how a type gives its instances an API. Two names in here are contracted — see below. | | `M.modules` | `{ [name] = require(".sibling") }` | Shared code the type's instances reach through `asset.containing(__FILE__).modules.<name>`, resolved by the instance's pinned `typeRef` guid. See the section above. | | `M.refShapes` | `{ [method] = "TypeName" }` | Declares the result type of a `M.ref` method so the LSP can check what a call site does with it. See the `M.refShapes` section below. | | `M.events` | an events schema | The events an ASSET of this type fires, declared the way a component declares its own. Readers subscribe through `ref.events.<name>:connect(...)`; firing authority stays with the type. Keyed by the asset's guid, so every resolver of the same asset shares the signals and a re-resolved ref re-attaches to subscriptions already there. | | `M.namePattern` | a Lua pattern string | The name shape `asset.create` enforces for instances of this type, replacing the default `^[A-Za-z][A-Za-z0-9_]*$`. | | `M.global` | `{}` | Reserved. Ship the empty table. | ### The lifecycle hooks Each is optional; a type that omits one costs nothing. The engine calls them: | Hook | Signature | When it fires | |------|-----------|---------------| | `M.onCreate` | `(name, opts) -> { [filename] = contents }` | On `asset.create("<type>", name, opts)`. Returns the files that scaffold the new instance, as a map of relative path to contents; the framework writes them. The `opts` type annotation is the schema `asset.create` validates the caller's arguments against, so annotate it. | | `M.onReplace` | `(dest, files) -> { [filename] = contents }` | On an `asset.create` that writes over an asset already at `dest`, after `onCreate`. Receives the files `onCreate` produced and returns the files to write, so a type that re-derives its content (a rig re-imported from its source file) can carry what an author added to the asset it replaces. Optional. | | `M.onRegister` | `(self)` | Once per instance, the first time it registers: on `engine.onWorldLoaded` for instances already in the world, immediately on a live `asset.create`, and when an instance arrives after that sweep (installed, pulled, or synced from a peer). Guarded by the instance's path, so a double trigger never double-registers. An instance that leaves the runtime releases the guard, so one arriving at the same path again registers. This is what makes "write an asset into the world and it takes effect live" work for content that registers into a runtime registry. The `@builtin` library is excluded from the sweep. | | `M.onChange` | `(ref, change)` | On every VFS write to a file INSIDE one of this type's instances. `change` is `{ path, asset, type, kind, origin }`: `kind` is `"edited"` or `"seeded"`, `origin` is `"local"` or `"remote"` (an importer runs on the originator only). **Filter on `change.path`**: the hook fires for any file under the folder, so act on the one you care about. It runs as its own task and may wait on what it reads: a `vfs.read` of bytes only the blob store holds (a binary file on the web build) fetches them. The writes to one asset reach the hook in the order they were made, each once the hook before it has finished. A re-entrancy guard suppresses writes back into the same asset routed inline from the hook, and a write the hook makes is routed on a later frame like any other, so the hook must be convergent on its own: diff the meaningful state and short-circuit while your own regeneration is in flight. | | `M.onDelete` | `(ref)` | When an instance of this type leaves the runtime: it is deleted, or the engine swaps away from the world binding that held it. Its files are gone from `/zero/source` by then. A removal routed while the instance's `onChange` is waiting reaches `onDelete` once that hook, and every write queued behind it, has finished. On a swap the instance still exists in the world it belongs to, and a VFS write the hook makes reaches the world now bound. | | `M.validate` | `(assetRef) -> { { code, message, severity? } }` | On `asset.validate`, after the structural `type.yaml` check, for the type's own SEMANTIC validation. `severity` defaults to `"error"`; error-severity problems flip `ok` to false, warnings do not. A hook that raises or returns a non-table is itself reported as a `validate.hook_failed` error. `world.push` runs this per user asset, so declaring it enforces your type's rules at publish time with no further wiring. | ### The two contracted `M.ref` names Most `M.ref` methods are your type's own surface: name them what you like, return what you like. Two are read by the engine and mean the same thing for every type, so their shape is fixed: - **`instantiate(self, target?, opts?) -> (root, idMap)`** — makes an instance part of the scene. Defining it is the whole opt-in: `ref:canInstantiate()` is true exactly when it exists. Its **return is a contract** — see the next section. - **`inspect(self) -> detail`** — the type-specific half of `asset.inspect`. See its section below. ### Names a type cannot shadow Some keys resolve on every `AssetRef` before per-type dispatch, so an `M.ref` entry of the same name is never reached: `canInstantiate`, `getSource` / `getBytes` / `getText`, `exists`, `deps`, `meta`, `runtime`, `events`, `modules`, `typeRef`, and the residency flags `has_backing_asset`, `has_runtime_changes`, `cpu_resident`, `gpu_resident`. These are the behaviours every asset must expose identically, which is why they win. ### Reloading A `behavior.luau` edit ripples to existing refs with no restart: dispatch reads `mod.ref` fresh each time and `require`'s cache is re-run in place. A type whose folder appears at runtime is picked up on the next dispatch — negative results are not cached either. ## The names your type's assets hold (`references:`) An asset that names another asset by a string depends on it: the named asset travels with it into a pack or a pull, and a name nothing answers to is an unresolved dependency `worldValidation` reports and the push gate refuses. The engine reads `require(...)` and the asset lookups on its own; a name your type's format or API carries anywhere else is one you declare, in `type.yaml`: ```yaml references: # A top-level key of this type's own files that holds a name (or a table of them). keys: - { key: "shader", type: "shader" } # A call's argument, counting from 1, wherever the call is written. args: - { call: "g:node", position: 2, type: "procNode" } # A field of the options table a call takes. fields: - { call: "fx.beam", field: "material", type: "material" } ``` `type` is the category the name resolves in, one of `asset.categories()`. An argument declared once per category, at the same `call` and `position`, takes the name from whichever category answers. A key or a field holds one category: declared again with another `type`, it takes the later one. The block is declared as the type registers, when the library or the world holding it is laid into the VFS, so every reference table reads it whatever script has or has not run. `asset.declareReferenceKey`, `asset.declareReferenceArg` and `asset.declareReferenceField` declare the same things from a script, for a surface that is no type's. ## What search does with your type (`indexing:`) A type declares what search embeds for its instances. **This is not optional and there is no useful default**: ZeroMind runs your declaration and adds nothing of its own, so anything you do not point at is absent from the index — silently, and for every instance of the type forever. Twenty types once shipped with no `indexing:` block and every instance of them was unfindable. A type whose instances are never searchable (a run record, a log) says so with `indexing: none`; every other type declares a recipe. A type without an `about.yaml` beside its `type.yaml` refuses every push that carries it, whether or not the push edited the type. Texts in it that are not written yet follow the rule every `described` file follows: they refuse the push that edits, stages or commits the type. Two words carry the whole thing, and they are the same two the search tool exposes: - **`identity`** — what an instance IS. For anything you can look at, that is the picture (`content:` + `modality: image`, matched directly by a text query). For everything else it is the authored text that says what it is. - **`capability`** — what it DOES and how it is made. Code, settings, the model-written summary of them. A type with no behaviour has no `capability` entry. A type with nothing to look at has no image. Leaving a slot empty is a statement; filling it with whatever happens to be lying around is not. The one you have to decide when authoring a type is: *for an instance of this, what is the thing a person would recognise it by, and what is the thing it does?* A texture answers "the image" and "its compression settings". A module answers "its README" and "its code". Write those two answers into `indexing:` and the rest follows. Three specifics worth knowing before you write one: - **`derive` is instructed by this type's own `README.md`.** A model reads an instance's source and writes a description; what it embeds is the description, not the source. It follows your README to know what it is looking at, so a type whose README says what its instances are gets good derivations for free. There is no prompt to name. - **`derive` loses detail.** It keeps the main technique and drops secondary ones. If the source is code you want searchable by its own vocabulary, declare the same files a second time as `capability` with `extractor: verbatim`. Two entries, same role, different failure modes. - **Never `source: { field: name }`.** A filename is one or two words with no usable embedding, and a corpus indexed that way answers "language runtime" with `say_runtime_2.soundClip`. `facets:` is the second stage: a `file:` embedded whole (`.metadata`, so keys nobody declared still get indexed) plus computed keys that state a value for every instance including `false` — the raw file can imply "not rigged" and can never say it. The full schema, every extractor and the facet sources are in [`assetTypes/README.md`](../README.md); the scaffolded block with inline guidance is in [`template/type.yaml`](template/type.yaml). ## A container whose contents work together (`system: true`) A type that is a container can say its contents are one working whole by declaring `system: true` at the top level of its `type.yaml`. `package` declares it: the components, modules, scenes and tools a package ships are parts of one system. The declaration is plain data, read from the decoded `type.yaml` (`require("@builtin::assetTypes.assetType.shared.declaration").of("package").system`), and a type that leaves it out is an ordinary type. ## What your type looks like (`preview:`) A type declares how its instances are pictured, and the engine makes the picture when something needs it: staging an instance whose `preview.png` is missing or pictures content it no longer holds queues a render, a view that shows the instance asks for one, and `ref:preview()` renders one on demand. An edit renders nothing on its own. Each `preview.png` records the content it pictured, which is how a stale one is told from a current one. The preview studio owns the light, the backdrop, the framing and the camera, and nothing in the world reaches it, so an instance pictures the same in every world. Declare one of four recipes: | `kind` | The picture is | Your type provides | |---|---|---| | `instantiate` | the asset stood in the studio through its own `instantiate` | `ref.instantiate` | | `image` | a file the instance holds, fitted to the frame, nothing rendered | `source.files`, the candidate files in order | | `surface` | the asset painted on a builtin mesh | `mesh`, and `ref.previewMaterial(self) -> { material }` | | `custom` | whatever `ref.preview(self, opts)` returns | `ref.preview` | ```yaml preview: kind: surface mesh: sphere ``` A scene-instantiable type that declares nothing still answers `ref:preview()` through its `instantiate`, but persists no picture: the declaration is what makes the engine keep one. List `preview.png` among the type's files so an instance may hold it. The picture is findable only when `indexing.content` names it. The two are separate statements, and neither is derived from the other: ```yaml indexing: content: - role: identity modality: image source: { file: "preview.png" } ``` `@builtin::assetTypes.assetType.shared.previewRecipe` reads the declaration; the scaffolded block with inline guidance is in [`template/type.yaml`](template/type.yaml). ## Typing a result from the instance (`M.refShapes`) Every method on `M.ref` is checked against the type its `--!return` names, and every asset of the type gets the same one. That is right for most methods and wrong for the ones whose result is shaped by the ASSET: a method answering one entry per child folder, per row of a config, per binding an input map declares. The widest true annotation for those is `{ [string]: Thing }`, and an indexer accepts every key — so a caller's typo reads as valid and nothing reports. `M.refShapes` lets the type state the result per instance. Each entry is `function(self) -> (typeExpression, source?)`: a Luau type expression for THIS asset, and the module whose type vocabulary the expression uses. Read the asset; never run it — stating a type must not take effect. ```lua -- inputMap.assetType/behavior.luau — the shipped example. -- `activate()` hands back one handle per control the map declares. M.refShapes = { activate = function(self): (string, string) local names = {} for _, control in ipairs(M.ref.controls(self)) do table.insert(names, control.name .. ": Handle") end if #names == 0 then return "", "" end return "{ " .. table.concat(names, ", ") .. " }", "@builtin::modules.zinput.scheme" end, } ``` With it, `map.jump:onPressed(fn)` resolves and `map.noexisting` is reported with the map's real controls. Without it, both pass silently. ### What the call site has to say A per-instance type is matched by the asset's IDENTITY, so it applies only where the reference the method is called on says WHICH asset. Two spellings do: ```lua -- a component field, whose declared default names the asset public = { map = Field.assetRef("inputMap", "@builtin::inputMaps.default", Sync) } local controls = public.map:activate() -- typed for THAT map -- an annotation, naming category and identity local m: AssetRef<"inputMap", "@builtin::inputMaps.default"> ``` `asset.resolve("<identity>", "<category>")` carries the CATEGORY, so the methods the category defines are checked on the result — but not which asset it found, so a per-instance result keeps the category's declared return. A reference that names no asset (`asset.resolve(someVariable)`, a value passed in as a parameter) carries neither, and calls on it are unchecked. That is the same rule everywhere: the checker states what the code states, and a name computed at runtime states nothing. ### The result is a value, not a binding The type belongs to the expression, so it travels the way any inferred type travels. Indexing the call's result is checked; stashing it in a module local and indexing it from another function is not, because the local's declared type is what carries across — and `any` (or no annotation) carries nothing: ```lua -- checked: `d.greting` is reported function awake() local d = public.dialogue:lines() d.greeting:say() end -- NOT checked: `lines` is a module local typed `any` local lines: any = nil function awake() lines = public.dialogue:lines() end function start() lines.greting:say() end ``` Bind what you need at the call site and the names stay checked in both places — the asset-derived type at the boundary, ordinary scoping after it: ```lua local lineGreeting = nil function awake() local d = public.dialogue:lines() lineGreeting = d.greeting -- `d.greting` is reported here end function start() lineGreeting:say() end ``` ### When nothing is reported and you expected something From a call site, a type that is correct and a type that was never published look the same: no diagnostic either way. `require("@builtin::assetTypes.assetType.shared.refShapes").published()` answers which it is. It returns two maps — the category surfaces, and the per-asset results keyed by identity and then by method: ```lua local shapes = require("@builtin::assetTypes.assetType.shared.refShapes").published() shapes.categories.dialogue --> "{ lines: () -> any, lineNames: () -> { string } }" shapes.returns.Shopkeeper.lines --> "{ browsing: Line, farewell: Line, greeting: Line, wares: Line }" ``` An identity absent from `returns` was never published for, which is a different thing from published-and-correct — and the reason to look here rather than at the call site. The answers are recomputed when an instance is written, so a control added to a map reaches the checker with no restart. Only types that declare `refShapes` are read per instance, and at most 64 assets of one type are — past that the type keeps its declared return and the engine log names what was dropped. ## The instantiate hook (`M.ref.instantiate`) — a contracted return A type opts into becoming part of the scene by defining `instantiate` on its `ref` table. That is the whole opt-in: `ref:canInstantiate()` is true exactly when the hook exists, so consumers offer a scene path — an `Asset.source` field, a viewport drop, a tool argument — by CAPABILITY rather than by a list of type names. Unlike `inspect`, this hook's **return is a contract**. A caller writes one piece of code against every instantiable type, so what comes back cannot vary by type: ```lua -- behavior.luau local Instantiable = require("@builtin::assetTypes.assetType.shared.instantiable") local M = {} M.ref = { instantiate = function(self, target, opts) local root = Instantiable.root(self, target, opts) -- IN: the base opts -- ... compose whatever this type is, under `root`, NOW ... return Instantiable.result(self, root, idMap) -- OUT: the contract end, } return M ``` **IN.** `target` is an owning entity ref: the instance lands under (or, for a hierarchy type, onto) that owner. With no target the type spawns a fresh root. `position`, `rotation`, `scale`, `name` and `temporary` mean the same for every type — `Instantiable.root` applies them to a root you mint, `Instantiable.place` to one you adopt, so you never re-read the spec. Honour more opts of your own if your type needs them, and document them in the hook's `--!arg` docs. **OUT.** Return `(root, idMap)` through `Instantiable.result`: - **`root`** — the composed root, as an `EntityRef`. Composition is **synchronous**: everything your type builds is live when you return, so the caller can parent to it and read its components in the same statement. Do not defer the work to a component's `awake` and return an empty shell — a root that is not live is refused. - **`idMap`** — the `originalId -> runtimeId` map naming what you spawned, or nil for a type with no addressable children (`result` normalises it to `{}`). **A caller never receives nil.** A component that re-composes your asset on every load keeps this map and passes it back in, which is how a cross-entity reference into the composition survives a reload. `AssetRef` runs every `instantiate` through `result` on the way out whether or not your type called it, so returning something else fails at your own call rather than handing a caller a nil root. Calling it yourself is still how you say what you return, and running it twice changes nothing. `@builtin::assetTypes.assetType.shared.instantiable`'s README is the full reference for both halves. ## The inspect hook (`M.ref.inspect`) `asset.inspect(ref)` resolves `ref`, builds a common envelope shared by every asset (`identity`, `name`, `guid`, `source`, `typeName`, `typeDefinitionPath`, `scope`, `origin`, `description`, `tags`), then calls the resolved type's own inspect hook — `M.ref.inspect(self)` on `behavior.luau` — for the type-specific `detail`. The hook returns *only* `detail`; the framework fills in everything else: ```lua -- behavior.luau local M = {} M.ref = { inspect = function(self) -- self.path is the asset's own folder. Parse the asset's OWN -- files — source text, a native payload header, its `.metadata` -- — never runtime state (a live component instance, a GPU -- upload, a compiled schema): inspect must work on an asset that -- hasn't been compiled, uploaded, or registered yet. return { -- type-specific fields, whatever this type wants to surface } end, } return M ``` A type that omits `M.ref.inspect` yields the generic record: the envelope alone, `detail = nil`. That's a valid, working state — not an error — but it means agents calling `asset.inspect` / `tools.use("assets","describe", ...)` on an instance of the type see only identity and scope, none of what makes an instance of it meaningful. Declaring the hook is what makes a type's instances inspectable for what they actually are. A hook that raises leaves `detail = nil` and sets `record.warning` to the error text — `asset.inspect` itself never raises for a resolved ref. ## Discovery - `asset.list("assetType")` — every registered asset type. - `asset.inspect("<typename>")` — the type's identity, source path, and this README, plus its `about.yaml` texts as `detail.about`. - `asset.resolve("<typename>", "assetType")` — the `<typename>.assetType` asset itself (used by the validator to find the type's `type.yaml`). ## Related - `assetTypes/README.md` — the full `type.yaml` schema and validator rules. - `@builtin::assetTypes.assetType.shared.instantiable` — the instantiation contract's shared implementation, both halves. - Every other `*.assetType/` here — the concrete types built on this meta-type. ## The Inspector a type ships Every type names the file its Inspector sections come from with `inspector: { type: "inspector.luau" }` in its type.yaml. `asset.create("assetType", name)` scaffolds the block and an `inspector.luau` whose Contents section lists an asset's files, built from `ctx.parts`. `asset.validate` on a type that names none reports `assetType.inspector_required` (an error for a `@builtin` type the engine's library authors; a warning for a world's own, and for one the library carries by reference, which the world that published it answers for), and one whose file does not load `assetType.inspector_invalid`. ## In the Inspector Type: what the type.yaml declares (suffix, container, primary files, the settings and inspector blocks), whether the type ships a behavior, how many instances it has, and **Open** for its files. Schema: the settings every instance carries, as read-only typed controls at their defaults (a type whose schema is per instance says where it is declared). Instances: a link to each of the first 20 assets of the type, and how many there are when there are more.

# actions A name-registered action registry over `Zin.bindings` + `Zin.context`. A name maps to a list of binding descriptors and one declared context; polling queries (`held`, `pressed`, `released`, `value`, `heldTime`, `repeated`) evaluate those bindings against the live snapshot, and the handler surface (`bind` / `onPressed` / `onReleased` / `onChanged` / `onHeld`) fires the same state from inside `Zin.tick`, after axes and chords advance. A control asset replaced this. A `<name>.inputBinding/` folder inside an `.inputMap/` carries the label, the kind, and a binding for keyboard-and-mouse, gamepad and touch, and a world activates the map and subscribes to the controls it uses: ```luau public = { inputMap = Field.assetRef("inputMap", "@builtin::inputMaps.default", NoSync, "The controls this component reads."), speed = Field.number(5, NoSync, "World units per second at full deflection."), jumps = Field.number(0, NoSync, "How many times the jump control was pressed."), } local controls function awake() controls = public.inputMap:activate() controls.move:onInput(function(v, dt, active) if not active then return end local p = public.entity.position local step = public.speed * dt public.entity.position = { p.x + v.x * step, p.y, p.z - v.y * step } end) controls.jump:onPressed(function() public.jumps += 1 end) end function onDestroy() public.inputMap:deactivate(controls) end ``` `Zin.map.bake(name)` writes the currently active map out as an `.inputMap` asset. `man topics/input` covers the control model. ## Exports Registry: - `M.define(spec: ActionSpec)` — define / replace actions. - `M.remove(name: string)` — remove one action (also tears down handlers). - `M.clear()` — wipe every action + handler. - `M.has(name: string) -> boolean` - `M.names() -> { string }` - `M.get(name: string) -> ActionEntry?` — the registry record behind a name. - `M.active(name: string) -> boolean` — true iff the action's context matches the top of the stack. Polling queries (gated by context): - `M.held(name) / pressed(name) / released(name) -> boolean` - `M.value(name) -> number | Vec2 | 0/1` - `M.heldTime(name) -> number?` - `M.repeated(name, opts?) -> boolean` Event-driven handlers: - `M.bind(name, fn, opts?) -> ActionHandle?` — register a handler. - `M.disconnect(handle: ActionHandle) -> boolean` - `M.onPressed / onReleased / onChanged / onHeld(name, fn, opts?) -> ActionHandle?` - `M.handlerCount(name) -> number` Internal hooks (wired by `zinput/init.luau`): - `M._setAllocator(fn: () -> number)` — shared id allocator. - `M._setEnsureBindingsFn(fn)` / `M._setEnsureLiveFn(fn)` — the cold-read hooks. - `M._owns(handle: number) -> boolean` - `M._dispatchHandlers(firstTickThisFrame: boolean?)` — called by `Zin.tick`. - `M._clearHandlers()` — test isolation. Types: - `ActionEntry = { context: string, bindings: { any } }` - `ActionSpec = { [string]: any }` — define-spec entry shapes. - `ActionState = "Begin" | "Change" | "End" | "Held"` - `BindOpts = { priority: number?, fire: { ActionState }?, once: boolean? }` - `ActionHandle = number` ## Notes - Define-spec shorthand: - `binding` — single binding under the default context. - `{ binding1, binding2 }` — multiple bindings under the default context. - `{ context = "...", binding = ... }` / `{ context, bindings = {...} }` — explicit context. - Context gating is strict: the action's context string must equal `Zin.context.current()`. There is no inheritance up the stack. - Handlers run from `Zin.tick` after axes/chords advance. With no tick host (or `Zin.autoTick.start()`), handlers never fire. - Returning `"sink"` from a handler stops further (lower-priority) handlers on the same action this tick. Anything else continues. - A handler also ends with the context that bound it: one a component binds ends when that component instance goes (removed, hot-reloaded, or its entity despawned), one a module body binds at the module's next run. `scopes.list()` names each as a `luau` row under the context it follows. - `remove(name)` and `clear()` also wipe handlers bound to those actions — handler state never outlives its action. - The handler allocator is swapped at boot (`_setAllocator`) so handles drawn here share one namespace with `Zin.input.on*`.

# arming The predicate a look-style control hands to its `gate`, in the one place it is written. Backs `Zin.arming`. A mouse always has a delta, so an ungated mouse-look turns the camera whenever the cursor crosses the window. The gate answers "is the player steering?" — and every scheme answers it with the same list of gestures in a different combination. `Zin.arming.gate(opts)` takes the combination and returns the predicate. ```luau local Arming = require("@builtin::modules.zinput.arming") return { label = "Look", kind = "axis2", gate = Arming.gate({ dragZone = "right", stick = "right" }), kbm = B.mouseDelta(), gamepad = B.padStick("right", { as = "delta", unitsPerSecond = 1200 }), touch = B.touchDrag({ zone = "right" }), } ``` A locked pointer always arms: a cursor the scheme took is one the player gave to the camera. The rest is named in `opts` — `dragZone` for a finger inside a touch zone, `stick` for a deflected pad stick, `padButtons` for a trigger, `virtualButtons` for an on-screen button. ## The right mouse button `rightButton` is the field the schemes disagree about, because the button means two different things. | Value | Arms while | Used by | |-------|-----------|---------| | `"free"` (default) | the button is down and no other control that can answer on it declares it | the player scheme | | `"held"` | the button is down | the editor scheme, where holding it IS the fly gesture | | `"off"` | never | a control that reads the button through nothing but pointer lock | `"free"` is what lets a world bind the right button to a game action. The engine's default scheme arms mouse-look on that button, and a world that also binds it would otherwise get the camera turn and its own action from one gesture, with no way to decline the camera half short of standing down its whole control group. Under `"free"` the world's binding is the claim: declare the button in a live `.inputMap` control, or in the `Zin.actions` / `Zin.axes` registry, and the arming stands down for as long as that control can answer on it. A control whose map is standing down for a suppressor, or whose context is not the one on top, is one the player cannot reach — the same two terms the tick's own dispatch reads before it evaluates a control — so the button is free of it while that holds and the camera keeps the drag. `Zin.arming.rightButtonClaimants()` names who is holding it, which is the answer to "why did my right-drag stop turning the camera": ```luau Zin.arming.rightButtonClaimants() --> { "map:torch.torchToggle" } ``` The engine's own arming gesture — the `lookDrag` control on the standard scheme, and the `look_drag` action beside it in the registry — is what `"free"` arms FROM, so those two names are passed over by the search. A claim is decided on the frame the button goes down and holds until it comes up. A map activating mid-drag therefore cannot take a gesture away from the camera halfway through it, and the search runs once per press rather than once per gated control per frame.

# autoTick Opt-in per-frame tick loop for zinput. Spawns a `task.spawnSystem` worker that invokes a registered tick function (`Zin.tick`) once per frame, so code-mode snippets and tests without a host script component still drive the stateful subsystems — live binding dispatch, the touch overlay, the emulation floor, axes, chords, rebind, action handlers, event subscribers. `task.spawnSystem` (not `task.spawn`) makes the loop system-owned, so it keeps ticking while the editor pauses gameplay. The first real input read arms this worker on its own. A host script component can also call `Zin.tick(dt)` from its `update(dt)` hook, and `autoTick.start` can be called directly; all three are idempotent alongside each other. ## Exports - `M.start() -> boolean` — spawn the worker if not already running. Returns true when a new loop was started. - `M.stop()` — flag the loop to exit on its next yield. No-op if not running. - `M.isRunning() -> boolean` — current status. - `M._setTickFn(fn: (number?) -> ())` — internal hook. Called once by `zinput/init.luau` to register `Zin.tick`. - `M._setLastTickFrameIdFn(fn: () -> number)` — internal hook. Wires the frame-id accessor so the worker can dedup itself against explicit ticks within the same engine frame. ## Usage ```luau local Zin = require("@builtin::modules.zinput") -- One-shot test / code-mode setup: Zin.autoTick.start() -- ... later ... Zin.autoTick.stop() ``` ## Notes - Single-flight: calling `start()` twice is a no-op — there is at most one worker per VM. - Cross-coroutine dedup: when an explicit `Zin.tick` ran in the same engine frame, the worker skips that frame so `onHeld` handlers and event subscribers don't double-fire. - Module-local `_running` survives Luau require-cache reload, so a re-required `autoTick.module` still reports the loop is live. `restart_instance` resets the VM and clears everything. - `start()` raises if `_setTickFn` hasn't been wired yet — always `require("@builtin::modules.zinput")` first.

# axes A name-registered axis registry over `Zin.bindings`. Any axis or vector binding becomes a `Zin.axes` entry with optional deadzone, exponential smoothing, curve shaping, invert, context gating, and a per-frame gate function. Stateful — `Zin.tick` calls `advance(dt)` each frame to evolve the smoothed reading. A control asset replaced this. An `axis1` / `axis2` `<name>.inputBinding/` inside an `.inputMap/` carries a binding for keyboard-and-mouse, gamepad and touch, so one control reads a stick and a dragging thumb as well as a key, and the binding's own `as` / `unitsPerSecond` / `scale` bring every class into one unit. It declares the same `deadzone`, `smoothing`, `curve` and `invert`, applied by `Zin.scheme` through the same `Zin.utils` maths this reads: ```luau public = { inputMap = Field.assetRef("inputMap", "@builtin::inputMaps.default", NoSync, "The controls this component reads."), speed = Field.number(5, NoSync, "World units per second at full deflection."), jumps = Field.number(0, NoSync, "How many times the jump control was pressed."), } local controls function awake() controls = public.inputMap:activate() controls.move:onInput(function(v, dt, active) if not active then return end local p = public.entity.position local step = public.speed * dt public.entity.position = { p.x + v.x * step, p.y, p.z - v.y * step } end) controls.jump:onPressed(function() public.jumps += 1 end) end function onDestroy() public.inputMap:deactivate(controls) end ``` `Zin.map.bake(name)` writes the currently active map out as an `.inputMap` asset. `man topics/input` covers the control model. ## Exports Lifecycle: - `M.define(spec: AxisSpec)` — define / replace axes. - `M.remove(name: string)` / `M.clear()` — drop one / all axes. - `M.has(name) -> boolean` / `M.names() -> { string }` / `M.get(name) -> AxisDef?` Reads: - `M.value(name: string) -> any` — smoothed value (`number` for scalar, `{ x, y }` for vector). - `M.raw(name: string) -> any` — raw unsmoothed binding value. Tick hook: - `M.advance(dt: number)` — internal; called by `Zin.tick`. - `M._setEnsureBindingsFn(fn)` / `M._setEnsureLiveFn(fn)` — internal cold-read hooks. - `M._resetGateWarnings()` — test helper. Types: - `Curve = string | (number) -> number` — `"linear"` / `"quadratic"` / `"cubic"` / custom. - `AxisDef = { binding, deadzone, smoothing, curve, invert, context, gate, kind }` - `AxisSpec = { [string]: any }` — define-spec. ## Notes - `smoothing` is the exponential time constant in seconds. `0` means "snap to target instantly". Higher = laggier. - `deadzone` is radial for vector bindings — magnitude under the threshold zeros both axes — and scalar for scalar bindings. - Context gating is strict: the axis's declared context must equal `Zin.context.current()`. Mismatch snaps target to 0, and `advance` smooths current down toward 0. - A throwing `gate` falls through to "ungated" for that frame and logs one warning per axis per session (state cleared via `_resetGateWarnings()`). - Without a tick host (or `Zin.autoTick.start()`), `value()` returns the last computed snapshot; `raw()` always reads live.

# back Back, and the claims a world holds on it. Backs `Zin.back`. Back is the platform's own Back: Android's Back button and back gesture, and a keyboard's Back key (`BrowserBack`, which a browser names the same). A world binds any control of its own to it with `Zin.back.press`, which is how Escape or a pad's button becomes Back too. The engine routes every Back press to the first of these that stands: 1. the topmost overlay on screen that states how it is dismissed: an open `popup` carrying `onDismiss`, or an open, dismissible `modal` carrying `onClose`. Its dismissal runs, the way Escape runs it. 2. the claim held that takes it (`Zin.back.claim`: the highest priority, and the most recent among equals): its handler runs. 3. nothing: the platform's own default answers. On Android the app moves to the background; a desktop window and a browser page stay where they are. A claim says ahead of the press that the world takes Back, which is what Android's predictive back asks for: the system decides before a back gesture begins whether it previews going home. Hold a claim while Back means something to the world and release it when Back should leave. Every press is a `back` event in `input.events()`: `{ kind = "back", taker = "overlay" | "claim" | "none" }`. ## Exports - `M.claim(handler, { priority? }) -> Claim`: take Back. Of the claims held, the highest priority (0 when omitted) takes a press no overlay takes, and the most recent among equals. The editor's claim that leaves play is held at -1, under every claim a played world makes. `claim:release()` gives it up, `claim:held()` says whether it is held. A claim a component makes is released when its entity is destroyed. - `M.press()`: press Back, routed as above. - `M.claims() -> number`: how many claims are held. ## Usage ```luau local Zin = require("@builtin::modules.zinput") local claim local function closeMenu() menu.close() if claim then claim:release() claim = nil end end local function openMenu() menu.open() claim = Zin.back.claim(closeMenu) end -- Escape as Back too, through the world's own control. controls.pause:onPressed(Zin.back.press) ```

# bindings Binding primitives and evaluators. A binding names which physical input satisfies a control on one device class — the value a `.inputBinding` record's `kbm` / `gamepad` / `touch` field holds. A binding is a plain descriptor table (e.g. `{ kind = "key", code = "KeyW" }`); the evaluators (`evalHeld`, `evalPressed`, `evalReleased`, `evalAxis`, `evalVector`) dispatch on `kind` and read `Zin.state` / `Zin.virtual` to produce the live signal. `Zin.scheme` runs them once per tick for every live binding, and they are public so chords, axes and library authors can evaluate a binding without reimplementing the dispatch. ```luau -- boost.inputBinding/init.luau local B = require("@builtin::modules.zinput.bindings") return { label = "Boost", kind = "button", kbm = { B.key("ShiftLeft") }, gamepad = { B.padButton("left_shoulder") }, touch = { B.touchButton({ zone = "right-lower" }) }, } ``` ## Two frames, and which binding speaks which - **Stick bindings** (`vector`, `touchStick`, `padStick`) report the direction the player *means* — forward is `+y`. A `move` control carrying a keyboard class and a stick class drives both devices the same way. - **Delta bindings** (`mouseDelta`, `touchDrag`, `scroll`) report movement that happened — down is `+y`, because that is what the pointer did. They also differ in magnitude: a stick is a position bounded at 1.0, a delta is however far the device moved this frame. A control carrying both — look, zoom — declares `as = "delta"` on its held class with the `unitsPerSecond` a full deflection is worth, and `scale` on a delta class that counts in its own units (a pinch in pixels beside a wheel in notches). `Zin.scheme` applies both, so one sensitivity covers every device. ## Exports Keyboard and mouse constructors: - `M.key(code: string) -> Binding` - `M.mouse(button: string) -> Binding` — `"left"` / `"right"` / `"middle"`. - `M.modKey(spec: string) -> Binding` — `"Ctrl+S"`, `"Shift+Alt+P"`, `"Escape"`. - `M.axis(plus: Binding, minus: Binding, opts: StickOpts?) -> Binding` - `M.vector(right, left, up, down: Binding) -> Binding` - `M.wasd() -> Binding` - `M.arrowKeys() -> Binding` - `M.mouseDelta(axis: string?) -> Binding` — this frame's mouse delta. - `M.scroll(axis: string?) -> Binding` — scrollwheel delta. - `M.pointerLocked() -> Binding` — boolean, true while locked. Touch constructors (fed by `Zin.virtual`, which the on-screen controls write): - `M.touchStick(opts: { zone, axis? }) -> Binding` — vector. - `M.touchButton(opts: { zone?, label?, icon?, priority?, size?, group? }) -> Binding` — boolean. - `M.touchDrag(opts: { zone, axis? }) -> Binding` — per-frame delta vector. - `M.touchPinch(opts: StickOpts?) -> Binding` — scalar pinch delta. Gamepad constructors (addressed by canonical position; `slot` names one pad, omitting it means any connected pad): - `M.padButton(button: string, slot: number?) -> Binding` - `M.padAxis(axis: string, opts: StickOpts?) -> Binding` - `M.padStick(stick: string, opts: StickOpts?) -> Binding` - `M.padTrigger(trigger: string, slot: number?) -> Binding` Predicates: - `M.isBoolean(b) -> boolean` - `M.isAxis(b) -> boolean` - `M.isVector(b) -> boolean` Evaluators: - `M.evalHeld(b) -> boolean` - `M.evalPressed(b) -> boolean` - `M.evalReleased(b) -> boolean` - `M.evalAxis(b) -> number` - `M.evalVector(b) -> Vec2` Pretty-printers: - `M.format(b: any) -> string` — single binding ("Space", "Ctrl+S", "WASD"). - `M.formatAll(bindings: any?, sep: string?) -> string` — joined summary; non-table arg returns `"<no bindings>"`. Types: - `Binding = { [string]: any }` — descriptor table with `kind` plus type-specific fields. - `Vec2 = { x: number, y: number }` - `StickOpts = { slot: number?, as: string?, unitsPerSecond: number?, scale: number? }` ## Notes - Bindings are pure data tables — they serialize cleanly, compare with `Json.encode`, and have no metatables. - `modKey` normalises modifier order in `format()` so a key written as `Shift+Ctrl+KeyS` displays the same as `Ctrl+Shift+KeyS`. The internal `mods = { ctrl, shift, alt }` flags are the canonical representation. - Mouse-delta, scroll, drag and pinch values are raw physical deltas, not clamped to `[-1, 1]`. `as = "delta"` + `unitsPerSecond` on the stick class beside them is what puts every class in one unit. - `as = "delta"` needs `unitsPerSecond` and has no default: the number that makes a pad feel right is the point of declaring the conversion, and a default would be right for one control and quietly wrong for the next. - Reading a member this module does not have raises immediately, naming the nearest members and the full list — a wrong guess at a constructor surfaces at the call rather than as `attempt to call a nil value` later. - `format()` always returns a string, never throws — returns `"<invalid>"` for malformed input.

# chords Chord and sequence state machines. Two kinds: - `sequence` — ordered steps with a per-step window and an overall window (Konami-style codes). - `simultaneous` — N bindings pressed inside a tolerance window, order-insensitive (piano-chord / fighter-combo style). Chords are edge-triggered — `fired(name)` is `true` for exactly one frame when the full pattern completes. A continuous combo like "Ctrl+S held" is a `button` control whose `kbm` class is `B.modKey("Ctrl+S")`: a chord recognizes a pattern over time, which is a different question from whether a combination is down right now. ## Exports Lifecycle: - `M.define(spec: ChordSpec)` — define / replace chords. - `M.remove(name) / M.clear()` - `M.has(name) -> boolean` / `M.names() -> { string }` / `M.get(name) -> ChordDef?` Queries: - `M.fired(name) -> boolean` - `M.progress(name) -> number` (0..1) - `M.cancel(name)` — reset state. Subscriptions: - `M.onFire(name, callback, opts: OnFireOpts?) -> OnFireHandle` - `M.off(handle: OnFireHandle)` Tick hooks (called by `Zin.tick`): - `M._beginTick()` — clears per-frame fire flags. - `M._observeEvent(ev)` — advance state machines on an input event. - `M._advanceTime(dt)` — age out stale recognizers. - `M._dispatchFires()` — invoke onFire callbacks for chords that fired this tick. Types: - `ChordDef = { kind, context, steps?, stepWindowSec?, windowSec?, bindings?, toleranceSec? }` - `ChordSpec = { [string]: any }` - `OnFireOpts = { context: string?, once: boolean? }` - `OnFireHandle = { id: number, name: string, off: () -> () }` ## Usage ```luau local Zin = require("@builtin::modules.zinput") local B = Zin.bindings Zin.chords.define({ konami = { kind = "sequence", steps = { B.key("ArrowUp"), B.key("ArrowUp"), B.key("ArrowDown"), B.key("ArrowDown"), B.key("ArrowLeft"), B.key("ArrowRight"), B.key("ArrowLeft"), B.key("ArrowRight"), B.key("KeyB"), B.key("KeyA") }, stepWindowSec = 0.5, windowSec = 4.0, }, }) Zin.chords.onFire("konami", function() unlockBonus() end) ``` ## Notes - Without a tick host (or `Zin.autoTick.start()`) chords never fire — every state machine is dormant until `Zin.tick` drives it. - A wrong key in a sequence resets to step 0. If the wrong key happens to match step 1, the recogniser restarts from step 1 on the same event (so a long input run can self-recover). - For simultaneous chords, the tolerance window starts on the first matched press. If all bindings haven't matched before `toleranceSec` elapses the state resets — `firstPressAt` is reset too so the next press starts a fresh window. - Subscriber errors are caught and logged via `log.warn`.

# zinput / clock The wall-clock time source for zinput's time-window features — held-time and synthetic key repeat (`state`), chord step / total windows (`chords`), and the tick's fallback delta (`init`). `nowSeconds()` reads the engine's per-frame `getTime()` (seconds since engine start, published from the native clock), which advances with wall time on every platform. `os.clock` measures CPU time and barely moves across scheduler yields on wasm, so it is only the fallback for contexts with no engine time surface. ## API - `nowSeconds() -> number` — current wall-clock seconds for input timing. - `_setClock(fn: (() -> number)?)` — internal; override the clock with `fn` (returns seconds) or `nil` to restore the default. For deterministic timing: fixed-step replay and tests that need a controllable clock.

# conflicts Binding-conflict detection — reverse index over the `Zin.actions` / `Zin.axes` registries. Two bindings "conflict" when they map to the same canonical leaf key (e.g. both bind `Space`, or an action binds `Space` and an axis's `plus` side is `Space`). Backs `Zin.conflicts`. Rows carry a `kind = "real" | "intentional"` classification: two or more action owners in the *same context* are `real`; action + axis overlaps, cross-context actions, and explicitly marked pairs are `intentional`. `realOnly()` is the noise-filtered view the Input tab uses; `forActiveProfile()` is the full audit list. ## Exports Marking: - `M.markIntentional(actionA: string, actionB: string) -> (boolean, string?)` - `M.unmarkIntentional(actionA: string, actionB: string) -> boolean` - `M.isIntentional(actionA: string, actionB: string) -> boolean` - `M.listIntentional() -> { { string } }` Probing: - `M.bindingKey(b: any) -> string?` — `"key:Space"`, `"modKey:Ctrl+KeyS"`, `"mouse:left"`, or `nil`. - `M.find(binding: any) -> { Owner }` — owners that share any leaf key with the probe. - `M.forActiveProfile() -> { ConflictRow }` — every shared-key row. - `M.realOnly() -> { ConflictRow }` — subset where `kind == "real"`. Internal (wired by `zinput/init.luau`): - `M._setPersistFn(fn)` — registers the save-back closure. - `M._loadIntentionalPairs(pairs_)` — seed on profile activate. - `M._serializeIntentional() -> { { string } }` — for profile save. - `M._resetIntentional()` — test isolation. Types: - `Owner = { target: string, name: string, slot: any }` — `target` is `"action"` or `"axis"`. - `ConflictRow = { key: string, owners: { Owner }, kind: string }` — `kind` is `"real"` or `"intentional"`. ## Usage ```luau local Zin = require("@builtin::modules.zinput") -- Audit view (e.g. inside the Input tab): for _, row in ipairs(Zin.conflicts.forActiveProfile()) do print(row.key, row.kind, #row.owners) end -- Suppress an intentional same-context overlap: Zin.conflicts.markIntentional("crouch", "slide") ``` ## Notes - `modKey` leaf keys list modifiers alphabetically (`Alt+Ctrl+Shift`), so `Shift+Ctrl+KeyS` and `Ctrl+Shift+KeyS` compare equal. - Continuous-source bindings (`mouseDelta`, `scroll`, `pointerLocked`) never appear in conflict reports — two axes reading `mouseDelta` is by-design. - Persistence: `_setPersistFn` is wired by `zinput/init.luau` so marks flow into the active profile JSON without conflicts needing a hard dep on profile. - The classifier counts every same-context action pair. If even one pair is unmarked, the row is `"real"`; otherwise `"intentional"`.

# context The input context stack. Pushing a named context ("ui", "menu", "vehicle", ...) stands down everything whose declared context doesn't match the top of the stack; popping restores the previous mode. The bottom is permanently `"default"` so unbalanced pops never leave the stack empty. A control, an action, an axis or an event subscriber can declare one context. `Zin.scheme` honours it on every live binding, so a vehicle-context Brake neither fires nor draws its touch button while the default context is on top. A map standing another map's `group` down is the coarser instrument beside this one: `group` / `suppresses` on an `.inputMap` decides which whole schemes answer, while a context decides which entries within a live scheme do. ## Exports - `M.default() -> string` — the always-on context name (`"default"`). - `M.push(name: string)` — push a context. No-op when `name` is not a non-empty string. - `M.pop() -> string?` — pop the top context; returns `nil` when only `default` remains. - `M.current() -> string` — name at the top of the stack. - `M.contains(name: string) -> boolean` — true if `name` is anywhere in the stack. - `M.stack() -> { string }` — a copy of the live stack, bottom→top. - `M.reset()` — pop everything except `default`. - `M.with<T...>(name: string, fn: () -> T...) -> T...` — run `fn` with `name` pushed, pop guaranteed. ## Usage ```luau local Zin = require("@builtin::modules.zinput") -- menuClose.inputBinding/init.luau declares `context = "ui"`, so it reads -- only while "ui" is on top. Zin.context.push("ui") Zin.context.current() -- "ui" Zin.context.pop() Zin.context.with("ui", function() -- inside this block the "ui" controls are the ones that read end) ``` ## Notes - The stack lives in the module's upvalues, so it persists across Luau script runs that share the require cache. A `restart_instance` resets it (matches the standard caching contract). - Pushing the same context twice requires two pops to fully remove — matches typical UI nesting (a sub-menu pushes "ui" again). - A declared context is compared strictly equal to `current()`; there's no inheritance up the stack.

# controllers Reusable controller factories on top of the `Zin.actions` handler, `Zin.context` and `Zin.state` surfaces. Each factory returns a stateful controller object with the `:start / :stop / :update / :isActive` lifecycle and a small set of intent readers. `free`, `orbit` and `fps` read keyboard and mouse, and their `gamepadIndex` opt is accepted and ignored. `vehicle` reads an input map, so every control answers to keyboard, gamepad and touch. ## Exports Factories (module-level): - `M.free(opts: FreeOpts) -> FreeController` — free-fly designer/debug camera (WASD plane + Q/E vertical + Shift sprint + mouse-look). Writes the entity transform directly. - `M.orbit(opts: OrbitOpts) -> OrbitController` — orbit camera around a target (drag-rotate, scroll-zoom, optional pan). - `M.fps(opts: FpsOpts) -> FpsController` — first-person walker. Produces motion intent for the host (`getDesiredVelocity`, `consumeJumpRequest`, `isSprinting`, `isCrouching`); convenience `applyToTransform` writes directly. - `M.vehicle(opts: VehicleOpts?) -> VehicleController`: driving intent for a ground vehicle, read from `opts.inputMap` (an inputMap ref or its path; `@builtin::inputMaps.vehicle` by default): `getThrottle` (-1..1, positive forward), `getSteer` (-1..1, positive right), `getBrake` (0..1), `isHandbrakeHeld`, `isBoosting`, `consumeRecoverRequest` (true once per press), `consumeZoom` (wheel notches since the last read). `:start` activates the map, which stands the walking scheme down for as long as it is live; `:stop` releases it. The `VehicleController` component drives a car's `WheelCollider`s from this intent. Controller-object methods (returned by the factories; called with `:`): - `:start()` — define actions, push context, optionally request pointer-lock. - `:stop()` — drop actions, pop context, release pointer-lock if `:start` took it. - `:isActive() -> boolean` - `:update(dt: number)` — per-frame; no-op when context doesn't match. - `:actionNames() -> { string }` - `FreeController`: `:setMoveSpeed`, `:setLookSensitivity`, `:getCameraYaw`, `:getCameraPitch`, `:getVelocity`. - `OrbitController`: `:getDistance`, `:getYaw`, `:getPitch`, `:setDistance`, `:setTarget`. - `FpsController`: `:setMoveSpeed`, `:setLookSensitivity`, `:getCameraYaw`, `:getCameraPitch`, `:getDesiredVelocity`, `:isSprinting`, `:isCrouching`, `:consumeJumpRequest`, `:applyToTransform`. Types: - `FreeOpts`, `OrbitOpts`, `FpsOpts` — opts tables; `entity` is the only required field. - `VehicleOpts`: `{ inputMap?, label? }`; every field is optional. - `FreeController`, `OrbitController`, `FpsController` — opaque (typed as `any` so the metatable plumbing doesn't fight the LSP). ## Usage ```luau local Zin = require("@builtin::modules.zinput") local cam = Zin.controllers.free({ entity = cameraEntityId }) cam:start() -- per frame: Zin.tick(dt) cam:update(dt) ``` ## Notes - Each controller's actions are namespaced under `actionPrefix` (default `"free_fly."`, `"orbit."`, `"fps."`). Two co-existing controllers with overlapping prefixes will trample each other — override the prefix when stacking. - The context push/pop pair makes `Zin.context.push("ui")` cleanly suppress every controller without `:stop`. The controller's `:update` early-outs when `Zin.context.current()` doesn't match. - Rotation convention: yaw=0, pitch=0 → `(0, 0, -1)` (-Z forward). Mouse Δx adds to yaw; mouse Δy subtracts from pitch (invert with `invertY = true`). Pitch is clamped to `[-π/2 + ε, π/2 - ε]`. - `FpsController` produces *intent* — gravity, collision, and the jump impulse are the host's responsibility. The `consumeJumpRequest()` accessor returns `true` once per press, so the physics step can fire its impulse exactly once. - Free / FPS request pointer-lock at `:start` (opt out with `requestPointerLock = false`) and only release it on `:stop` when they were the ones who acquired it.

# emulation Map-driven input-emulation floor. Reads `Zin.virtual` (the store on-screen touch controls write) each tick and emulates the equivalent kbm keys / mouse delta, so raw-key-polling worlds (`Zin.state.keyDown`) move from touch input without themselves reading `Zin.virtual` or `Zin.bindings`. Backs `Zin.emulation`. ## What it derives, per tick, from the active effective map Only entries whose `context` matches the current input context (`Zin.context.current()`) participate — the same activity rule `Zin.actions` applies, so a vehicle-context Brake button emulates nothing while the default context is on top. - **touchButton actions** — the OR of every touchButton binding in an action's touch class drives its first kbm `key` binding's code, emulated on the held state's transitions. Actions with no kbm key binding are skipped. - **touchStick axes** whose kbm class is a `vector` of four `key` arms (the `B.wasd()` / `B.arrowKeys()` shape) — each stick component thresholded at `+-0.5` drives the matching direction key. The stick's y is screen-down positive (`Virtual.setStick`'s convention), so negative y (stick pushed up) drives the vector's `up` arm and positive y its `down` arm. - **touchDrag axes** whose kbm class is `mouseDelta` — the drag delta, scaled by `M.setSensitivity`, emulated via `input.emulateMouseDelta` whenever it's non-zero. A control that is already a live binding (`Zin.scheme.has(name)`) is skipped: its touch class drives it directly, and synthesising a key for it as well drives it twice, from opposite conventions. The judgement is per control, because a world can subscribe to some things and poll raw keys for others. Emitted keys are tracked locally and diffed each tick — a held key is emulated once, on the press transition, never re-emitted every tick a control stays held. Switching the active map (name change between ticks) or the input context (top-of-stack change) releases everything emitted under the previous map/context. ## Exports - `M.setSensitivity(n: number)` / `M.getSensitivity() -> number` — the touchDrag -> mouse-delta multiplier (default `1.0`). - `M._advance()` — internal: one tick of the floor, called by `Zin.tick`. - `M._reset()` — test-only: release everything emitted, clear state. ## Usage ```luau local Zin = require("@builtin::modules.zinput") Zin.map.ensureActive() Zin.emulation.setSensitivity(1.5) -- Zin.tick(dt) advances the floor; a virtual Jump press then reads as -- Zin.state.keyDown("Space") for any world that only polls kbm state. ```

# events Frame-event readers and edge-event subscriptions. Wraps the internal `__zero_input.events()` FFI with per-kind filters and a push-style `on/off` API that fires from `Zin.tick`. Backs `Zin.events`. `__zero_input.events()` returns the current frame's events in dispatch order; reading does not consume them. Subscription dispatch happens during `Zin.tick` (or `Zin.autoTick.start()`'s worker), so without a tick host `on()` callbacks never fire. ## Exports - `M.frame() -> { InputEvent }` — this frame's events in dispatch order. - `M.iter() -> iterator` — `ipairs` over `frame()`; reads better at call sites. - `M.keysDown / keysUp / mouseDowns / mouseUps / mouseMoves / mouseWheels / texts() -> { InputEvent }` — per-kind filters. - `M.on(filter: EventFilter, callback, opts: SubOpts?) -> SubHandle` — register an edge subscriber, returns handle. - `M.off(handle: SubHandle | number)` — cancel a subscriber. - `M.clearSubscribers()` — drop all subscribers (test isolation). - `M.subscriberCount() -> number` — current subscriber count. - `M._dispatch(events)` — internal; called by `Zin.tick`. Types: - `InputEvent = { [string]: any }` — one entry of the frame event log. - `EventFilter = string | { [string]: any } | (any) -> boolean` - `SubOpts = { context: string?, once: boolean?, priority: number? }` - `SubHandle = { id: number, off: () -> () }` ## Usage ```luau local Zin = require("@builtin::modules.zinput") for _, ev in ipairs(Zin.events.frame()) do if ev.kind == "key.down" and ev.code == "Space" then -- jump on the press edge, not on every frame the key is held end end local h = Zin.events.on({ kind = "key.down", code = "Escape" }, function(ev, gpe) if not gpe then closeMenu() end end, { context = "ui" }) -- later: h.off() ``` ## Notes - Reading `frame()` is non-destructive — multiple consumers can iterate the same frame's events. The log clears at end-of-frame and is rebuilt next frame. - Subscribers dispatch in priority-desc order; equal priorities preserve insertion order. Returning `"sink"` from a callback halts further dispatch for that single event (lower-priority subscribers skipped). - `once = true` subscribers auto-unsubscribe after their first matching dispatch. - A subscription ends with the context that made it as well as with `off`: one a component makes ends when that component instance goes (removed, hot-reloaded, or its entity despawned), one a module body makes at the module's next run. `scopes.list()` names each as a `luau` row under the context it follows. - Subscriber errors are caught and logged via `log.warn`; one bad handler doesn't break dispatch.

# gamepad The pad-facing surface: which controllers are connected, what family they belong to, and what a legend should call a canonical button on them. Backs `Zin.gamepad`. Bindings never come through here. A scheme binds `B.padButton("south")` and evaluates against whichever pad is connected; this module answers the questions a UI asks — how many players have controllers, and which letter to draw on a prompt. ## Position, not letter The canonical layout names a button by POSITION, because position is what every pad shares — `south` is the lower face button on all of them. The letter printed on it is not shared: `south` is `A` on an Xbox pad, `Cross` on a PlayStation one, and `B` on a Nintendo one. `label()` resolves that from the device name the platform reported, so a binding stays device-independent and only the drawn glyph changes. Anything unrecognised reads as `xbox`, because the standard mapping every backend normalises to is the Xbox layout. ## Exports - `M.list() -> { Pad }` — every connected pad, in slot order. - `M.count() -> number` — how many pads are connected. - `M.get(slot) -> Pad?` — the pad in one slot. - `M.family(slot?) -> string` — `"xbox"` | `"playstation"` | `"nintendo"`. - `M.label(button, slot?) -> string` — the legend for a canonical button. - `M.available() -> boolean` — whether the session has ever seen a pad. Latched by the first connection, so unplugging one does not flip a scheme's prompts back to keyboard glyphs on a cable knock. Types: - `Pad = { slot, name, buttons, buttons_pressed, buttons_released, axes, simulated }` — the button fields are arrays of canonical names, `axes` a map of canonical axis name to number, and `simulated` marks a pad that came from the `inputSim` toolbox rather than a device. ## Usage ```luau local Zin = require("@builtin::modules.zinput") if Zin.gamepad.count() >= 2 then startLocalCoop() end ui.text("Press " .. Zin.gamepad.label("south") .. " to jump") ```

# gestures Touch-gesture recognizers over the touch event stream + contact snapshot; backs `Zin.gestures`. Discrete gestures (tap, double-tap, long-press, swipe) fire subscriptions; continuous gestures (pinch, pan) expose per-tick deltas computed from the two-finger contact state. Advanced by the `Zin.tick` pipeline — dormant until ticked. ## Discrete vs continuous - **Discrete** (tap / double-tap / long-press / swipe) — recognized on a release or hold-duration edge, delivered via `on*` subscriptions on the tick they fire. - **Continuous** (pinch / pan) — recomputed every tick from the two-finger contact positions; read via `pinchDelta()` / `panDelta()`, reset to zero at the start of each tick. The pair is formed from the contacts no on-screen widget is working, the ones `Zin.touchControls` says its stick and buttons hold having been left out, so a thumb on a movement stick is no part of a pinch. ## Config `Zin.gestures.configure` overrides recognition thresholds (unspecified fields keep their current values): | Field | Default | Meaning | |---|---|---| | `tapMaxDuration` | `0.25` s | press→release within this = tap candidate | | `tapMaxMovement` | `16` px | total movement below this = tap candidate | | `doubleTapWindow` | `0.3` s | two taps within this = double-tap | | `longPressDuration` | `0.5` s | held past this (still) = long-press | | `swipeMinDistance` | `60` px | release travel at/above this = swipe candidate | | `swipeMinVelocity` | `800` px/s | release velocity at/above this = swipe | ## Exports - `M.configure(opts: { [string]: number })` — override recognition thresholds. - `M.getConfig() -> GestureConfig` — current thresholds (a copy). - `M.onTap(fn) -> number` — subscribe to taps; `fn(ev)` with `ev = { x, y, id, duration }`. - `M.onDoubleTap(fn) -> number` — subscribe to double-taps; `ev = { x, y, id }`. - `M.onLongPress(fn) -> number` — subscribe to long-presses (fires once per contact); `ev = { x, y, id }`. - `M.onSwipe(fn) -> number` — subscribe to swipes (fires on release); `ev = { direction, dx, dy, velocity, id }`. - `M.off(handle: number) -> boolean` — unsubscribe a handle from any `on*` function. - `M.pinchDelta() -> number` — this tick's two-finger pinch delta in px (positive = spreading). - `M.panDelta() -> (number, number)` — this tick's two-finger pan delta `(dx, dy)` in px. - `M._beginTick()` — internal: clear per-tick continuous deltas; wired by `Zin.tick`. - `M._observeEvent(ev: any)` — internal: builds contact tracks and classifies discrete gestures on release; wired by `Zin.tick`. - `M._advanceTime(dt: number)` — internal: time-based recognition (long-press) + continuous deltas; wired by `Zin.tick`. - `M._setWidgetContacts(ids: { [number]: boolean })` — internal: the contacts an on-screen widget is working; published each tick by `Zin.touchControls`. - `M._pairDown() -> boolean` — internal: whether two contacts no widget is working are down, which is the pair a two-finger gesture reads. - `M._dispatchFires()` — internal: deliver this tick's discrete gesture fires; wired by `Zin.tick`. - `M._reset()` — test-only: clear all tracks, fires, deltas, and subscriptions. Types: - `GestureConfig = { tapMaxDuration, tapMaxMovement, doubleTapWindow, longPressDuration, swipeMinDistance, swipeMinVelocity }` (all `number`) ## Usage ```luau local Gestures = require("@builtin::modules.zinput.gestures") Gestures.onTap(function(ev) print("tap at", ev.x, ev.y) end) Gestures.onSwipe(function(ev) if ev.direction == "left" then nextPage() end end) -- inside a per-frame update: local zoom = Gestures.pinchDelta() local dx, dy = Gestures.panDelta() ``` ## Notes - Pinch and pan deltas are zero unless exactly two contacts are down this tick that no on-screen widget is working. - Long-press fires once per contact — the contact must stay within `tapMaxMovement` for the full `longPressDuration` and is marked so it never also fires a tap on release. - Every qualifying release fires `tap`; the second tap of a double-tap fires `doubleTap` and `tap` on the same tick. - Handler errors during dispatch are caught and logged, not propagated.

# input Event-driven listeners for whole categories of raw input, on top of `Zin.events.on`. Sugar for the most-common filter shapes (`onBegan` / `onEnded` / `onChanged` / `onTextInput`) plus a `lastInputType()` accessor. Backs `Zin.input`. These sit beneath the control model: they answer "any key went down" rather than "the Jump control fired", which is what rebind capture, dev tooling and text-adjacent UI need. Gameplay subscribes to controls through an activated map — `man topics/input` covers that path. ## Exports - `M.lastInputType() -> string?` — userInputType of the most recent input event (`"Keyboard"` / `"Mouse"` / `"Touch"` / `nil`). - `M.onBegan(fn, opts?) -> Handle` — fires on `key.down` / `mouse.down`. - `M.onEnded(fn, opts?) -> Handle` — fires on `key.up` / `mouse.up`. - `M.onChanged(fn, opts?) -> Handle` — fires on `mouse.move` / `mouse.wheel`. - `M.onTextInput(fn, opts?) -> Handle` — fires on committed text input; handler signature is `(text, gpe)`. - `M.disconnect(handle: Handle) -> boolean` — tear down a subscription; idempotent. - `M.subscriberCount() -> number` — number of active composite subscriptions. - `M._reset()` — test-only: clear `lastInputType`. - `M._disconnectAll()` — test-only: tear down every subscription this session. - `M._observeEvent(ev: any)` — internal observer driven by `Zin.tick`. - `M._setAllocator(fn: () -> number)` — internal: wire the shared handle-id allocator. - `M._owns(handle: number) -> boolean` — internal: handle-ownership check for cross-API disconnect. Types: - `Filter = string | { [string]: any } | (any) -> boolean` - `SubOpts = { priority: number?, context: string?, once: boolean? }` - `Handle = number` — composite-handle id, drawn from a shared allocator with `Zin.actions`. ## Usage ```luau local Input = require("@builtin::modules.zinput.input") local h = Input.onBegan(function(io, gpe) if io.kind == "key.down" and io.code == "Space" then print("jumped") end end, { priority = 10 }) Input.disconnect(h) ``` ## Notes - Handler signatures: `fn(io, gpe)` for `onBegan` / `onEnded` / `onChanged`; `fn(text, gpe)` for `onTextInput`. `gpe` is the event's own `consumed_by_ui` marker, stamped as the event arrived against the focus the UI holds over that event's surface: pointer focus for a mouse or touch event, keyboard focus for a key or text event, and never for a pad. - Return `"sink"` from a handler to stop further (lower-priority) handlers receiving the same event. - A single `on*` call installs N underlying `Zin.events.on` subscribers but returns ONE composite handle — `disconnect` tears them all down together. - A composite handle also ends with the context that made it: one a component registers ends when that component instance goes (removed, hot-reloaded, or its entity despawned), one a module body registers at the module's next run. `scopes.list()` names each as a `luau` row under the context it follows. - Handle ids share a namespace with `Zin.actions` (`_setAllocator` wires this at boot), so `Zin.actions.disconnect` accepts handles returned here. - `lastInputType` is updated by the tick observer; text events do not bump it (the preceding key.* event already did).

# map A record-shaped map: `Zin.actions` / `Zin.axes` entries organized per device class (`kbm` | `gamepad` | `touch`) with single-parent `extends`, materialized into an EFFECTIVE map and applied as one binding set at a time. Backs `Zin.map`. An `.inputMap` asset with `.inputBinding` children is the map, and `Zin.scheme` is the live set: several maps are live at once and compose, each declaring the `group` its controls belong to and the groups it `suppresses` while live. `Zin.map.bake(name)` writes the map active here out as an `.inputMap` asset, with synthesis made explicit and editable. `man topics/input` covers the control model. Resolution order per action/axis and device class: 1. the map's own class bindings 2. the `extends` parent's (recursively) 3. synthesis from the `kbm` shape (touch class only) A vector `kbm` binding synthesizes a `touchStick`; a boolean `kbm` binding synthesizes a `touchButton`; a vector-shaped `mouseDelta` synthesizes a `touchDrag`; `scroll` synthesizes a `touchPinch`; an `axis`-kind `kbm` binding and a single-axis `mouseDelta` are left unsynthesized (ambiguous which touch shape to guess). A synthesized `touchButton` carries `priority = 100` — an authored `B.touchButton`'s default priority (50) always outranks synthesis on the touch-controls overlay, so a hand-tuned scheme's own layout hints win over whatever filled a gap automatically. A profile record (actions with `bindings`, axes with `binding`) is accepted anywhere a map record is — its bindings are treated as the `kbm` class. ## Activation and the `<axis>@<class>` convention `activate` flattens every class's bindings into each action/axis's single bindings list and applies it through `Zin.profile`, so any device fires the action. For axes — which evaluate exactly one binding — the primary slot is the first of `kbm` / `touch` / `gamepad` present; any OTHER class's binding registers as a class-suffixed sibling axis (`look` + `look@touch`). A consumer that wants both device values reads both names; a kbm-only world's primary axis (`Zin.axes.value("move")`) behaves identically whether or not a touch class exists. `Zin.profile.ensureActive("default")` delegates to `Zin.map.ensureActive()` when the resolved scheme is the builtin default, so it carries every device class rather than kbm alone. `Zin.map.ensureActive()` / `Zin.map.activate` win regardless of call order (`activate` re-registers the flattened profile under the same name and forces a reactivate). ## Exports - `M.materialize(record: any) -> effective map` — resolve `extends` + synthesize, without activating. - `M.activate(record: any) -> effective map` — materialize + apply as the live binding set (registers/activates a `Zin.profile`). - `M.effective() -> effective map?` — the active map's materialized form. - `M.activeName() -> string?` — the active map's name. - `M.bindingsFor(eff, name, class) -> bindings?` — one action/axis's bindings for one device class. - `M.ensureActive() -> effective map` — keep the current map, else activate `@builtin::inputMaps.default`. - `M.bake(name: string) -> AssetRef` — write the active effective map as a new `.inputMap` instance (`asset.create("inputMap", name, { record = ... })`). - `M.addTouchButton(actionName, buttonOpts, emitKey?) -> binding` — add a touchButton binding to an action's touch class on the live effective map (creating the action if absent) and re-activate. Used by `Zin.touchControls.button`. - `M.removeTouchButton(actionName, binding) -> boolean` — remove a binding added via `addTouchButton` and re-activate; drops the action entry once every class is empty. - `M._reset()` — test-only: clear active-map state. ## Usage ```luau local Zin = require("@builtin::modules.zinput") Zin.map.ensureActive() local eff = Zin.map.effective() print(eff.actions.jump.classes.touch ~= nil) -- synthesized or explicit -- Write the active scheme out as a control-asset map: Zin.map.bake("my_scheme") ```

# observe What became of a device event, and why a live control did not fire. Backs `Zin.observe`. A control can be live, its device can be producing input this frame, and the game can still receive nothing. The input layer works out why every frame — a gate said no, a live map stood the group down, the UI took the pointer, nothing subscribed — and until something reads that decision it is thrown away. This module keeps it. ## The one question ```luau local Zin = require("@builtin::modules.zinput") Zin.observe.whySilent("look") --> { -- name = "look", -- layer = "scheme", -- map = "default", -- reason = "gateRefused", -- means = "the control's own gate answered no. A look control gates on -- the player steering, so a cursor crossing the window reads -- nothing.", -- kind = "axis2", -- subscribers = 1, -- declaredClasses = { "kbm", "gamepad", "touch" }, -- carriedBy = { "scheme" }, -- } ``` One reason, from a closed set, with the particulars behind it. `Zin.observe.reasons()` lists the whole set with a sentence each, so what an answer means is readable from inside the engine rather than only from the source. ## The closed set, nearest cause first | Reason | What it says | |---|---| | `noMapActive` | No input map is activated at all, so there are no controls. | | `unknownControl` | No live map declares a control under that name. | | `groupSuppressed` | A live map stands this control's group down. | | `contextInactive` | The control declares a context that is not on top of the stack. | | `heldOnArrival` | A device the control binds was already held when the control went live. The control reads the hold as held; `pressed` and `released` wait for the next press. | | `gateErrored` | The control's own gate raised. | | `gateRefused` | The control's own gate answered no. | | `noBindingForDevice` | The control declares no binding for any device class this session has. | | `belowDeadzone` | The devices produced a reading and the control's own deadzone zeroed it. | | `noSubscriber` | The control is delivering and nothing subscribed to it. | | `atRest` | The control is live and its devices are not being driven. | | `delivering` | The control is delivering its value to its subscribers. | `atRest` and `unknownControl` are the two an outside reader could never tell apart: a value reader answers `0` for both. This is where they separate. ## Which layer answered Three naming layers coexist: the live maps' controls, and the `Zin.actions` and `Zin.axes` registries a control asset replaced. Their name sets are separate — `toolMove` is a live control and not an action, `move_forward` is an action and not a control — so a name that is live in one reads as silence in the others. Every answer carries `layer` (the one that answered) and `carriedBy` (every layer that has the name at all). ## One control, everything about it ```luau Zin.observe.control("move") --> { -- name = "move", live = true, carriedBy = { "scheme" }, -- entries = { { map = "default", kind = "axis2", subscribers = 1, -- gated = false, classes = { kbm = {...}, gamepad = {...} } } }, -- lastTick = { value = { x = 1, y = 0 }, active = true, delivered = true }, -- why = { reason = "delivering", ... }, -- } ``` ## The frame ```luau Zin.observe.frame() --> { frameId = 41207, window = "one tick of binding dispatch — the most -- recent one", context = "default", maps = {...}, controls = {...}, -- cost = { frameId = 41207, maps = 3, controls = 27, ms = 0.09 } } ``` The window is **one tick** — the most recent one — rather than a sum since anything last looked, and reading takes nothing away from the next reader. Two observers in the same frame both get the truth. `cost.ms` is that one tick's own milliseconds. The same number lands in `profiler.stats("*zin.scheme.advance*")` as `script.zin.scheme.advance`, where it carries the average and the peak across every tick as well. ## Reading it without running a script `/runtime/input` serves the same answers as a file, beside the engine's own account of the frame's device events: ``` /runtime/input the whole document /runtime/input/events the frame's device events, each with `consumed_by_ui` /runtime/input/device pointer lock, UI focus, the session's device classes /runtime/input/mapping this module's account of the tick /runtime/input/controls/<name> one control's entry from that account ``` `input.observe()` returns the same document to a script. Building this layer's half costs a frame of work, so it is built only while something is reading: a read of either surface arms it for a window of frames, and the document's `mappingStatus` says whether the half it carries is `current`, `stale`, `arming` (this read armed it — read again), or `unarmed`. `Zin.observe.armedFrames()` is how many frames that window has left; each frame that passes takes one off it, and the per-frame publish spends the window rather than renewing it, so it runs out once the last reader stops asking. A window that runs out — or that `Zin.observe.arm(false)` closes — drops the report the engine was carrying with it, so a frame nobody observes costs what it cost before anything ever read. `Zin.observe.arm(true)` holds it open for a tool that wants it continuously. ## Which frame an answer covers `Zin.observe.frame()` and `Zin.observe.control()` report the most recent tick of binding dispatch. `Zin.observe.whySilent()` resolves against the devices as they are at the moment of the call, so it answers for a control the tick has never reached and for a name that does not exist. The engine publishes its own half at the end of a frame, after the frame has been drawn and before the frame's events are cleared. A read taken from a script during frame N therefore answers for frame N-1.

# pointer Pointer-lock mutation API. Wraps the internal `__zero_input.requestPointerLock` / `releasePointerLock` primitives and backs `Zin.pointer`. The read side lives on `Zin.state.pointerLocked()`; this module owns the write side plus a convenience read alias. ## Exports - `M.lock()` — request pointer lock (cursor grab + hide). Native takes effect immediately; WASM queues for the next user gesture. - `M.unlock()` — release pointer lock (cursor ungrab + show). - `M.locked() -> boolean` — convenience read alias, identical to `Zin.state.pointerLocked()`. ## Usage ```luau local Pointer = require("@builtin::modules.zinput.pointer") Pointer.lock() if Pointer.locked() then -- pointer captured end Pointer.unlock() ``` ## Notes - Native: `lock()` takes effect immediately. WASM: queued for the next user gesture (browser policy). Both routes share the same underlying FFI mutation; the platform enforces the difference. - Write side and read side are intentionally split: `Zin.state.pointerLocked()` stays alongside the rest of the per-frame snapshot accessors; mutation lives here for discoverability. - All entry points are no-ops when the `__zero_input` FFI is absent (off-host script execution).

# profile Binding profile registry — bundles of named actions / axes / chords that can be loaded from `@builtin::profiles.<name>` Luau modules or saved as JSON under `/zero/profiles/<name>.json`. Activating a profile reconfigures `Zin.actions` / `Zin.axes` / `Zin.chords` in one shot. The active profile is per-client session state held in memory — each session resolves it fresh from the device-appropriate default (or an explicit `activate`), so it is never written to the world source tree. This is the persistence and activation layer for those three registries; `Zin.map.activate` applies a materialized map through it. A scheme is authored as an `.inputMap` of `.inputBinding` controls and goes live through `Zin.scheme` — `man topics/input` covers that path. ## Exports - `M.register(name: string, profile: any) -> (boolean, string?)` — validate + register a profile descriptor. - `M.load(name: string) -> (boolean, any?)` — load + register a profile from `@builtin::profiles.<name>` or `/zero/profiles/<name>.json`. - `M.activate(name: string, opts: ActivateOpts?) -> (boolean, string?)` — apply a profile's sections + set the active name for this session. - `M.current() -> string?` — active profile name for this session, or nil. - `M.get(name: string?) -> any?` — descriptor for the active profile or the named profile. - `M.ensureActive(fallback: string?) -> (boolean, string?)` — bootstrap helper for controllers. - `M.save(name: string, opts: SaveOpts?) -> (boolean, string?)` — capture current Zin.actions / Zin.axes / Zin.chords to JSON. - `M.delete(name: string) -> (boolean, string?)` — remove a user profile's JSON file (built-ins refused). - `M.export(name: string, vfsPath: string) -> (boolean, string?)` — write a serializable JSON snapshot to any VFS path. - `M.import(vfsPath: string, opts: ImportOpts?) -> (boolean, string)` — read + register a profile JSON from any VFS path. - `M.list() -> { string }` — sorted union of built-in + user profile names. - `M.onChange(cb: ChangeCallback) -> number` — subscribe to activation / re-register events; returns a handle. - `M.off(handle: number)` — drop a subscription. - `M._reset()` — test-only: clear in-memory state. Types: - `Profile = { name, description?, actions?, axes?, chords?, intentional_pairs? }` - `ActivateOpts = { reactivate: boolean? }` - `SaveOpts = { description: string?, overwrite: boolean? }` - `ImportOpts = { overrideName: string?, activate: boolean? }` - `ChangeCallback = (string, any) -> ()` ## Usage ```luau local Profile = require("@builtin::modules.zinput.profile") Profile.register("my-bindings", { name = "my-bindings", actions = { jump = { context = "default", bindings = { { kind = "key", code = "Space" } } } }, }) Profile.activate("my-bindings") local h = Profile.onChange(function(name) print("active:", name) end) Profile.off(h) ``` ## Notes - Built-in profiles ship as Luau modules at `@builtin::profiles.<name>` and can include functions (gate, curve). User profiles are pure JSON at `/source/profiles/<name>.json` — function fields are dropped on save. - Activation is no-op when the requested name is already active unless `opts.reactivate = true`. - `save` / `export` VFS writes use the bare `/source/...` mount — the `/zero/...` prefix is read-only and silently drops writes. - The conflicts module's `_setPersistFn` hook is wired here so mark/unmark of intentional pairs persists into the active user profile automatically.

# quiesce The dirty signal `Zin.tick`'s quiescence gate reads. A mutation of the mapping layer's structure outside the tick itself — a map activation, a context change, a virtual-control write, a forced surface class, a new axis over an already-held key — calls `mark()`, and the tick runs a full pass while a mark is pending. A tick with no pending mark and no live input events skips its pass. `mark()` raises the signal, `pending()` answers whether a full pass is owed, and the generation pair (`generation()` / `ack(g)`) keeps a mark raised DURING a full pass pending for the next one, so a mutation racing a tick is never lost. Internal to the zinput package: the mapping-layer modules mark it, the tick drains it.

# rebind Interactive binding-capture sessions. A session listens for the next keyboard or mouse event and produces a binding descriptor; the host can then `apply()` it back into a `Zin.actions` action or a `Zin.axes` axis. Backs `Zin.rebind`. Drives the editor's Input tab rebinding UI and is usable from any Luau code. Modifier-aware (captures `modKey` when Ctrl/Shift/Alt is held) and timeout-bounded (default 30 s). ## Exports - `M.begin(opts: BeginOpts?) -> Session` — start a capture session; subscribes to `Zin.events.on` and returns a session table. - `M.cancelAll()` — cancel every live session. - `M.liveCount() -> number` — number of capturing sessions still active. - `M._advanceTime(dt: number)` — internal: per-frame timeout sweep wired by `Zin.tick`. Types: - `Session = { target, name, slot, mode, status, timeoutSec, result, consume, apply, cancel, conflicts, ... }` - `Owner = { target: string, name: string, slot: any }` - `BeginOpts = { target?, name, slot?, mode?, timeoutSec?, filter?, applyOnCommit?, onCommit?, ... }` ## Usage ```luau local Rebind = require("@builtin::modules.zinput.rebind") local s = Rebind.begin({ target = "action", name = "jump", timeoutSec = 10, applyOnCommit = true, onCommit = function(session) print("captured:", session.result()) end, }) -- The session subscribes itself; just wait for the next tick. if s.status == "capturing" then -- ... end ``` ## Notes - Press Escape during a capture to cancel; a pure modifier press is ignored (the session waits for the base key). - A session that captures with Ctrl/Shift/Alt held returns a `modKey` binding rather than a plain `key` binding. - `session.conflicts()` is self-filtered — rebinding an action to a key it already owns reports no conflict. - Hot-reload safety: the live-sessions list survives require-cache reload; the `_advanceTime` wiring from `zinput/init.luau` keeps timeouts firing across re-requires. - `applyOnCommit = true` calls `apply()` automatically after commit; errors during apply are still visible via `result()` and `conflicts()`.

# scheme The live set of activated input maps, and the per-frame dispatch that turns their bindings into the events a controller subscribed to. Backs `Zin.scheme`. ## Nothing is live until something activates a map A controller holds an `inputMap` ref, activates it when it takes control, and releases it when it gives control up. The live binding set is exactly the union of what current holders asked for, so an empty world has an empty input surface and an empty screen — no scheme is active by default, and nothing appears on a phone that no component consumes. For a component that drives the thing it lives on, taking control and being awake are the same moment, so `awake` / `onDestroy` are the hooks. For anything a player enters and leaves — a car, a turret, a menu — they are not: the car is still there after the player gets out, so the map goes live on entry and stands down on exit. ```luau public = { inputMap = Field.assetRef("inputMap", "@builtin::inputMaps.default", NoSync, "The controls this component reads."), speed = Field.number(5, NoSync, "World units per second at full deflection."), jumps = Field.number(0, NoSync, "How many times the jump control was pressed."), } local controls function awake() controls = public.inputMap:activate() controls.move:onInput(function(v, dt, active) if not active then return end local p = public.entity.position local step = public.speed * dt public.entity.position = { p.x + v.x * step, p.y, p.z - v.y * step } end) controls.jump:onPressed(function() public.jumps += 1 end) end function onDestroy() public.inputMap:deactivate(controls) end ``` What `activate` returned is this holder's **claim** on the map. Keep it and hand it back: releasing the claim disconnects the subscriptions made through it, and the map stays live for whoever else holds it. A claim also ends with the context that opened it. A component's claim is released when that component instance goes, whether or not it writes an `onDestroy`: the component is removed from its entity, the entity despawns, or the component hot-reloads (its new life's `awake` activates again). A claim a module body opens ends at the module's next run. `scopes.list()` names each standing claim as a `luau` row under the context it follows, and `scopes.release(tag)` ends it with everything else that context holds. ## Several maps compose by all being live The player's surface is the union of every live map, which is what a game needs: picking up a gun activates a weapon map and Fire appears beside the movement stick; dropping it takes away Fire and nothing else. Two controllers that each activate a map with a movement stick produce two sticks — visible, attributable to the second controller, and the importer's to resolve. Two components activating the *same* map read one set of controls, each through its own claim. A claim's release disconnects what that holder subscribed and leaves the other holders' handlers attached; the map leaves the live set when its last claim goes. `Zin.scheme.live()` reports each live map's `holders` — how many claims are still standing on it — and `heldBy`, which says who each of them is: `kind` (`"component"` or `"execute"`), `entity`, `source` as the `chunk:line` the activation was opened at, and the `label` the caller passed to `activate("weapon-swap")`. ## An activation reads the map's children as they stand now Every `activate` re-reads the map's `<name>.inputBinding/` children, so a control added, edited or removed since the map came up reaches the running set on the next activation. The controls are edited in place, so it reaches the holders already standing on the map too: their handles keep working and every subscription they made carries on across the edit. ## A map can stand another one down Composition cannot say "not while this is happening". A map declares the `group` its controls belong to and the groups it `suppresses` while live: ```luau -- driving.inputMap/init.luau return { group = "vehicle", suppresses = { "player" } } ``` Every live map in a suppressed group reads nothing and draws nothing for as long as the suppressor is live. It is **not** released: it keeps its holders, its handles and every subscription, and resumes untouched when the suppressor goes. So a car stands down walking without ever finding, owning or releasing the walk map — and a menu stands down the whole game with one declaration. A map that declares no `group` belongs to one named after itself, so it collides with nothing and can still be named by something that wants to stand it down. Declaring neither field composes with everything. The drop frame runs on the tick a map stands down, so a stick held at that moment reports its neutral value once and whatever it drove stops rather than sticking. ## Dispatch `_advance(dt)` evaluates every live binding once per tick, across every device class it carries — a tablet with a keyboard attached and a desktop with a pad plugged in both answer to whichever the player actually used, rather than to a nominated primary. | Event | Fires | Cadence | |---|---|---| | `input` | Once while the binding is active with `(value, dt, true)`, and once more on the frame it goes inactive with the neutral value and `false` | Per engine frame | | `pressed` / `released` | A button's edges | Per engine frame | | `changed` | When the value differs from the previous tick | Per tick | `input` firing on the drop frame is what lets one handler both start and stop the motion it drives, without a second subscription to notice the release. A frame carries more than one tick whenever a host calls `Zin.tick` beside the tick the engine already runs, or fast-forwards several ticks to converge smoothing. Evaluation follows the tick, so the smoothing lands and `changed` reports each step of it. `input`, `pressed` and `released` are stamped with the engine frame they were reported for, so the frame carries one of each however many ticks ran in it. Both edge sources hold this frame's edge for as long as the frame lasts: the input snapshot's `pressed` flag, and `Zin.virtual`'s previous-frame button table. That is what a second reporting pass reads as another press. `Zin.scheme.fired`'s `count` is the number of engine frames a control was active since it last cleared, so a button held across two frames reads 2 for one press. The `pressed` / `released` subscriptions are what count edges. A binding that declares a `context` is live only while that context is on top, the same activity rule actions apply. An `axis1` / `axis2` control's own `deadzone`, `curve`, `invert` and `smoothing` are applied here, in that order, to the reading its classes produced — after `as` / `unitsPerSecond` / `scale` have brought every class into the control's unit, so one deadzone written in that unit covers the stick, the mouse and the finger together. A deadzone is per value on an `axis1` and **radial** on an `axis2`. The shaping maths is `Zin.utils`', shared with the axis registry. `smoothing` is the one piece of the four that is stateful: the value is held per control across frames and approaches whatever the devices report next over the declared time constant. A control that leaves its context, whose group stands down, or whose gate closes has a neutral target, so it drains rather than cutting — and reports its drop frame when it arrives. ## Validation happens before anything registers Activation reads every child binding, collects every fault across all of them, and raises once with the lot. A map with three broken bindings names all three rather than one per attempt, and a map that fails validation registers nothing — a half-live map is worse to debug than one that refused to come up. ## Exports - `M.activate(mapRef, label?) -> { [name]: Handle }` — activate a map, return its handles. `label` names this activation in `M.live()`. - `M.deactivate(mapRef) -> boolean` — release a claim on a map. - `M.live() -> { { guid, name, group, suppresses, suppressedBy, holders, heldBy, bindings } }` — every live map in activation order. What tells an author why two sticks are on screen, or why the controls they activated answer to nothing, or who is holding the map standing them down. - `M.bindings() -> { { map, group, name, label, kind, context, suppressedBy, subscribers, record } }` — every live binding in activation order. The touch overlay builds from this, so what is on screen is exactly what some awake component asked for and nothing is standing down. - `M.suppressed() -> { [group]: mapName }` — which groups are standing down and what put each one down. - `M.has(name) -> boolean` — whether a named control is live anywhere. - `M._advance(dt)` — one tick of dispatch; wired into `Zin.tick`. - `M._childBindings(mapRef) -> { ref }` — the map's `.inputBinding` children, in name order. - `M._reset()` — test-only: drop every live map without firing anything. Types: - `Handle = { onInput, onPressed, onReleased, onChanged, label, kind }` — a thin view over the binding asset's own event facade, so a subscription made through a handle is the same one `ref.events.input:connect` would make and ends the same way.

# state Synchronous per-frame input state. Thin wrapper over the internal `__zero_input.snapshot()` FFI; backs `Zin.state`. Pointer-lock mutations live on `Zin.pointer`; the read-side `pointerLocked()` query lives here with the rest of the snapshot accessors. Held-time and synthetic-repeat state is owned by this module and updated via `_observeEvent` from the `Zin.tick` coordinator. ## Exports - `M.get() -> Snapshot` — full per-frame snapshot table; empty when the FFI is unavailable. - `M.keyDown(key: string) -> boolean` — held this frame. - `M.keyPressed(key: string) -> boolean` — edge-pressed this frame. - `M.keyReleased(key: string) -> boolean` — edge-released this frame. - `M.mousePosition() -> (number, number)` — current mouse `(x, y)`. - `M.mouseDelta() -> (number, number)` — `(dx, dy)` since last frame. - `M.scrollDelta() -> number` — wheel delta this frame. - `M.mouseButtonDown(idx: number?) -> boolean` — held; default idx = 0. - `M.mouseButtonPressed(idx: number?) -> boolean` — edge-pressed. - `M.mouseButtonReleased(idx: number?) -> boolean` — edge-released. - `M.pointerLocked() -> boolean` — pointer-lock query (writes are on `Zin.pointer`). - `M.uiWantsPointer() -> boolean` — `true` when the UI layer claims pointer focus. - `M.uiTookPress() -> boolean?`: `true` while a UI widget sensing a click or a drag holds the pointer press in progress; `false` with no press held and for a press on empty space; `nil` from the moment a press arrives until a UI pass has decided it. - `M.setRepeatDefaults(opts: RepeatOpts?)` — set default delay / period for synthetic repeat. - `M.getRepeatDefaults() -> RepeatDefaults` — read the active synthetic-repeat defaults. - `M.keyHeldTime(code: string) -> number?` — seconds since the key was pressed (or nil). - `M.mouseButtonHeldTime(idx: number?) -> number?` — seconds since a mouse button was pressed. - `M.keyRepeatFired(code: string, opts: RepeatOpts?) -> boolean` — should a synthetic key-repeat fire this frame? - `M._observeEvent(ev: any)` — internal: per-event observer, wired from the tick coordinator. - `M._reset()` — test-only: clear held-time and synthetic-repeat state. Types: - `Snapshot = { [string]: any }` - `RepeatOpts = { delay: number?, period: number? }` - `RepeatDefaults = { delay: number, period: number }` ## Usage ```luau local State = require("@builtin::modules.zinput.state") -- Rebind-capture-style probe: how long has a key been held, and is a -- synthetic repeat due this frame? local heldFor = State.keyHeldTime("Space") if heldFor and State.keyRepeatFired("Space", { delay = 0.4, period = 0.08 }) then -- charge-attack tick, key-repeat menu navigation, etc. end ``` ## Notes - Mouse-button indices are 0-based and follow `InputResource.mouse_buttons[]` (0=left, 1=right, 2=middle). Winit's `0=L, 1=M, 2=R` is converted in Rust before reaching Luau. - `mousePosition` / `mouseDelta` return two numbers, not a table. - Held-time / repeat state is updated by the `Zin.tick` coordinator via `_observeEvent` — without a tick, those queries return `nil` / `false`. - `keyRepeatFired` advances state on every call — call once per frame per consumer. - All entry points are no-ops or return zero values when `__zero_input` is missing (off-host execution). - Gameplay subscribes to controls through an activated `.inputMap`; this module is the raw snapshot layer those bindings evaluate against, used directly by rebind capture, the emulation floor, and dev tooling. Polling it from a world makes that world keyboard-only and draws the `engine-raw-key-poll` diagnostic at author time.

# surface Active input-surface classification. Answers "what device class is the player using right now" — `"touch"` or `"kbm"` — and notifies on change; backs `Zin.surface`. Virtual touch controls mount whenever the surface is `"touch"`, in edit and play alike. ## The frame rule Resolution runs once per engine frame from the `Zin.tick` pipeline: a per-event observer collects which device classes produced events this frame, and the frame resolver applies one rule — **touch wins a frame that contains any touch event**. The primary touch contact also drives the mouse path (a projected `mouse.down`/`move`/`up` in the same frame), so classifying by the latest single event would flip to `kbm` on every tap; the frame rule keeps projection-generated mouse events from masking the touch that caused them. ## Capability default Before any input arrives, the class defaults to `"touch"` on sessions with a touch source (`touch_capable` — latched by the first contact or declared at boot by Android / the web client) and `"kbm"` otherwise, so touch-first devices present touch controls from the first frame. ## Exports - `M.current() -> string` — the active surface class, `"touch"` or `"kbm"`. - `M.onChange(fn: (string, string?) -> ()) -> number` — subscribe to class flips; `fn(now, prev)` where `prev` is the previously reported class (the first-tick capability default when no event had resolved yet). Returns a handle. - `M.off(handle: number) -> boolean` — unsubscribe an `onChange` handle. - `M._beginFrame()` — internal: clear this frame's per-class flags; wired by `Zin.tick`. - `M._observeEvent(ev: any)` — internal: per-event observer; wired by `Zin.tick`. - `M._resolveFrame()` — internal: resolve this frame's class and fire `onChange` on a flip; wired by `Zin.tick`. - `M._reset()` — test-only: clear resolution state and subscriptions. Types: - `SurfaceClass = "touch" | "kbm"` ## Usage ```luau local Surface = require("@builtin::modules.zinput.surface") if Surface.current() == "touch" then showTouchOverlay() end Surface.onChange(function(now, prev) print("surface flipped to", now) end) ``` ## Notes - `onChange` fires from the `Zin.tick` pipeline on the frame the class flips; without a tick, resolution never advances and `current()` keeps returning the capability default. - The change signal compares against the last reported class, whose initial value is the capability default captured on the first tick of the session — a phone's first contact confirms the default silently, while a desktop touchscreen's first contact reports kbm→touch. - Handler errors during `onChange` dispatch are caught and logged, not propagated.

# test Test-input helpers that simulate keyboard / mouse / scroll events and yield one engine frame so the queued events drain into the next snapshot. Backs `Zin.test`. Helpers do NOT call `Zin.tick()` — explicit dispatch control is left to the caller. ## Exports - `M.runFrame()` — yield one engine frame so simulated events drain. - `M.pressKey(code: string)` — hold the key DOWN and leave it held. A second `pressKey` on a held key produces no new press edge — pair every `pressKey` with a `releaseKey`, or use `tapKey` for a full press. - `M.releaseKey(code: string)` — simulate a key release. - `M.tapKey(code: string, duration: number?)` — press + optional hold + release. The helper for "the player taps a key". - `M.pressMouse(button: (number | string)?)` — simulate a mouse button press (default 0 = left). The index and the name (`"left"`/`"right"`/`"middle"`) reach the same button. - `M.releaseMouse(button: (number | string)?)` — simulate a mouse button release. - `M.clickMouse(button: (number | string)?, x: number?, y: number?, duration: number?)` — full click, optionally moving the cursor to `(x, y)` first and holding for `duration` seconds. - `M.moveMouse(x: number, y: number)` — set absolute cursor position. - `M.moveMouseBy(dx: number, dy: number, steps: number?)` — move the pointer by a relative motion. The motion lands in this frame's `mouse_delta` and the position advances by the same amount, so the same `(dx, dy)` repeated keeps producing look movement. `steps` spreads it over that many frames, each carrying its share; 1 when omitted. - `M.scroll(dy: number)` — simulate a wheel scroll. ## Usage ```luau local Test = require("@builtin::modules.zinput.test") Test.tapKey("KeyM") -- press + release Zin.tick(1 / 60) -- explicit dispatch assert(#Zin.scheme.fired() > 0) Test.pressKey("Space") -- key goes DOWN and stays held... Zin.tick(1 / 60) Test.releaseKey("Space") -- ...until released Test.clickMouse(0, 100, 200) ``` ## Notes - Each helper queues the simulated event and yields one frame (`task.wait(0)`) so the snapshot reflects the input on return. - Simulated key state persists like real key state: after `pressKey` the key stays held until `releaseKey`, and only the release re-arms the next press edge. `tapKey` is the edge-per-call helper. - Helpers do NOT call `Zin.tick()` — a test that relies on a control's handlers, or on `Zin.input.on*` / `Zin.actions.bind`, must run a tick itself. `Zin.scheme.fired()` is what turns a simulated input into an assertion: it reports which controls fired since it last read, and from which device class. - Mouse button index is 0-based (0=left, 1=right, 2=middle) following the `InputResource.mouse_buttons` convention. - All helpers are no-ops when the `__zero_input.simulate*` FFI is missing (off-host execution).

# text Requiring this module raises a fatal error: `zinput.text` is not available in this build. ## Exports None — the module raises on `require`.

# touch Per-finger touch contacts. Thin wrapper over the `touches` array of the internal `__zero_input.snapshot()` FFI plus pre-baked `touch.*` event listeners; backs `Zin.touch`. ## Exports - `M.slots() -> { TouchPoint }` — all active contacts this frame, in begin order. - `M.count() -> number` — number of active contacts this frame. - `M.byId(id: number) -> TouchPoint?` — look up an active contact by finger id. - `M.primary() -> TouchPoint?` — the primary contact (slot 0), if a finger is down. - `M.capable() -> boolean` — whether the session has (or has declared) a touch source. - `M.onBegan(fn, opts?) -> handle` — subscribe to `touch.down` events. - `M.onMoved(fn, opts?) -> handle` — subscribe to `touch.move` events. - `M.onEnded(fn, opts?) -> handle` — subscribe to `touch.up` events. - `M.onCancelled(fn, opts?) -> handle` — subscribe to `touch.cancel` events. - `M.off(handle)` — unsubscribe a handle returned by any `on*` function. Types: - `TouchPoint = { id: number, slot: number, x: number, y: number, dx: number, dy: number, pressure: number, phase: string, pointer: boolean }` ## Contact record fields | Field | Meaning | |---|---| | `id` | The platform's stable finger id for the contact. | | `slot` | Lowest index free when the contact began; 0 = primary (also drives the mouse path). | | `x`, `y` | Screen position. | | `dx`, `dy` | This frame's accumulated delta. | | `pressure` | Normalized 0..1 (1 when the platform reports none). | | `phase` | `"began"` \| `"moved"` \| `"stationary"` \| `"ended"` \| `"cancelled"` (ended/cancelled contacts survive exactly one frame). | | `pointer` | Whether the contact drives the UI's pointer, so a widget under it can take its press. The primary contact does, unless it began on a region an on-screen control holds (`input.setTouchClaims`) or is a simulated contact for the game alone. | ## Usage ```luau local Touch = require("@builtin::modules.zinput.touch") for _, t in ipairs(Touch.slots()) do print(t.slot, t.x, t.y) end local h = Touch.onBegan(function(ev, gpe) print(ev.id, ev.x, ev.y) end) ``` ## Notes - `onBegan` / `onMoved` / `onEnded` / `onCancelled` are pre-baked kind filters over `Zin.events.on` — handlers dispatch from the `Zin.tick` pipeline and receive `(ev, gpe)` where `gpe` is the UI-focus flag at fire time. Return `"sink"` to stop lower-priority handlers from seeing the same event. - All entry points return empty / falsy values when `__zero_input` is missing (off-host execution).

# touchControls On-screen touch overlay: a renderer + worker, not an event-driven widget net. The worker reads raw touches (`Zin.touch.slots()`) and routes them into zone geometry derived from the live bindings, writing `Zin.virtual` (stick/button/drag). `Zin.tick` runs the worker early — after `Virtual._beginFrame()` clears the previous tick's drag deltas and before the binding evaluators read `Zin.virtual` — so the touch binding kinds consume those values on the SAME tick they're written. The renderer (a `canvas` screen declaring `pointerEvents = "none"`) only draws and takes no pointer, so every widget beneath it, in any screen at any layer, still receives the presses that land on it. Backs `Zin.touchControls`. ## Who a contact belongs to - A contact that begins on a drawn button, the fan or an open sheet entry is that control's alone. The overlay states those circles to the input layer with `input.setTouchClaims` (in the window pixels contacts arrive in), and a contact beginning inside one drives no pointer: no widget beneath the button is pressed by it, and no mouse button reads held. - A contact that begins anywhere else drives the pointer as the primary contact always does, and the UI decides whether a widget takes its press. When one does, the contact is the widget's: on the tick after it began, the stick or look zone that took it lets it go before it has moved anything. - Everything left falls to the stick and look zones below. ## Coordinate space Touch contacts (`Zin.touch.slots()` — `t.x`/`t.y`/`t.dx`/`t.dy`) carry PHYSICAL framebuffer pixels — `InputResource` keeps the raw platform coordinates unconverted, the same space `getViewportSize()` reports. Every widget geometry computation — button/stick positions, the canvas root's `style.width/height` — lives in `ui.screenSize()`'s LOGICAL space (the space `ui.registerScreen` / `ui.getLayoutInfo` use), which differs from the physical space whenever the display's `pixels_per_point ~= 1` (HiDPI). An internal `logicalScale` helper computes the `screenSize / viewportSize` ratio once per tick, and every touch coordinate this module reads is scaled by it before use. ## Safe area Every control keeps inside the part of the overlay no system bar, display cutout or on-screen keyboard covers. `ui.safeArea()` states that part of the picture the overlay's screen lays out in (the scene viewport's, at `ui.screenSize()`), and the overlay takes it into its own space, which leaves a safe rect `L`/`T` in from the left and top edges, `SW` x `SH` in size (the whole picture where the picture lies inside the window's safe area, as a Scene panel does). The zones, the button column and the stick all lie inside it, a contact beginning outside it starts none of them, and `layout().safe` reports it. ## Size on the glass Every radius, inset and gap is in the points `ui.screenSize()` reports. On a phone or a tablet a point covers at least the display's density (`ui.displayScale()`), so the controls keep one physical size on every phone and in both orientations: a 40 point "small" button is 80 dp across, past the 48 dp touch target. `layout()` reports the radii in points; multiply by the pixels one of the overlay's points covers for their size on the glass: the width `ui.getLayoutInfo("zin_touch_controls_canvas")` gives its canvas, over `layout().safe.width`, times `ui.pixelRatio()`. Button labels are canvas text sized from the button's radius, so the user's text scale leaves them inside their circles. ## Zone geometry (fractions of the safe rect, `SW`/`SH`) - **stick** - activation region `x < L + 0.4*SW and y > T + 0.4*SH` (left 40%, bottom 60%). A floating stick: the base spawns at the touch's start point, the thumb clamps to a 96px radius, and the vector fed to `Zin.virtual.setStick` is `offset / 96` with `y` screen-down positive (matching `setStick`'s documented convention). - **buttons** — one circle per `touchButton` binding among the LIVE bindings (`Zin.scheme.bindings()` — what awake components asked for, so every button corresponds to a control some world actually consumes), budgeted into a two-column band along the safe rect's right edge, between 45% of its height and its bottom edge less the inset. Buttons sort by `(priority, id)` - the touchButton's `priority` option, authored default 50, synthesized default 100 — with same-`group` buttons kept adjacent, then fill the two columns growing inward from the bottom-right corner. Each circle is the radius ITS OWN `size` option names (`small` 40px, `medium` 56px, `large` 72px), so a scheme mixing a `large` action button with a `small` pause pip draws them at 72 and 40 whatever else is live; the largest of those radii is the slot pitch and the row budget the column packs on, so the set decides where a button sits and the button's own declaration decides how big it is. More than 4 authored buttons walk every button one step down its own size, which `layout()` reports as `appliedSize`. Anything past the two-column budget doesn't render individually — the last slot becomes a `...` fan button; tapping it opens a rows-of-3 grid sheet holding the overflow (same tap/hold behavior as a regular button), and tapping the fan again, or any layout-invalidating context/map change, closes it. - **drag** - everything else in the safe rect at `x >= L + 0.4*SW` (accumulates into `Zin.virtual.addDrag` every tick from the contact's per-frame delta). - the remaining top-left quadrant (`x < L + 0.4*SW and y <= T + 0.4*SH`) is unclaimed - free for other UI. A control is drawn only when it is live AND subscribed: a button offered for a control nothing listens to is an offer that cannot be kept, so the layout tracks `Zin.scheme.subscriberEpoch()` alongside `Zin.scheme.generation()`. Only bindings whose `context` matches the current input context (`Zin.context.current()`) contribute controls, so a vehicle-context Brake button neither renders nor claims touches while the default context is on top. The layout rebuilds when the live set, the subscriber count, the context, the screen size or the safe area changes. A record-shaped map applied through `Zin.map.activate` contributes its touch classes too. A control whose name is already live as an asset is skipped, so a world carrying both never draws the same control twice under two ids. A contact is assigned to a region on its `began` phase only (a contact-id -> assignment map) and released on `ended` / `cancelled` / vanishing from `Zin.touch.slots()`. Button circle hit-tests (visible buttons, the fan, the open sheet's entries) take precedence over the stick/drag zone checks — a button is a precise target and wins wherever it lands, including inside a zone (the open sheet grows leftward and can reach the stick zone on a narrow screen). A contact claimed by the stick or a button never also feeds the drag zone (a contact is assigned to exactly one region), so its projected-mouse / `touchDrag` state never competes with a look/aim consumer reading `Zin.virtual.drag` — no extra suppression is needed beyond the region assignment itself. A pinch and the drag region share the same space, so the two are arbitrated once per tick. The contacts the stick and the buttons hold are published to `Zin.gestures`, which forms its two-finger pair out of what is left; while the active map declares a `touchPinch` control and that pair is down, the drag region reports nothing. A pinch made over the look surface therefore reaches the pinch control alone, a thumb resting on the movement stick is no part of a pinch so the other thumb keeps looking, and lifting one finger from a pinch drags again. ## Rendering One screen (`"zin_touch_controls"`, layer 200) whose root is a single transparent `canvas` sized to the safe rect, taking no pointer. The screen lays out inside the safe area, so the canvas starts at the rect's corner and every command is drawn from there. Commands rebuild only when the draw state actually changed (a dirty flag) — buttons are always drawn while mounted; the stick draws only while a stick contact is live. ## Auto-mount Every `_advance()` checks `Zin.surface.current()` — `"touch"` registers (lazily, once) and shows the screen; anything else hides it. Visibility is purely the surface class, in edit and play alike. `M._forceMount(true)` bypasses the surface gate for headless testing. Touch routing itself is unconditional: it runs every tick regardless of mount state, so a forced or real touch always drives `Zin.virtual` even before the overlay is visible. ## Adding a control while the world runs The overlay draws a button for a control that is live and subscribed, so adding one at runtime is adding a control asset, activating it, and subscribing to it — the three steps a component takes in `awake`, in one call: ```luau local h = Zin.touchControls.addControl({ name = "cast", label = "Cast", kbm = Zin.bindings.key("KeyF"), gamepad = Zin.bindings.padButton("north"), onPressed = function() castSpell() end, }) Zin.touchControls.removeControl(h) ``` The control becomes a real `<name>.inputMap/<name>.inputBinding/` under `/source/runtimeControls/`, so it is inspectable, rebindable and publishable like any other, and its name is its id in `Zin.scheme.bindings()` / `Zin.scheme.fired()`. `removeControl` releases it — off the screen, out of the live set, every subscription dropped — and leaves the asset, so re-adding the same name reuses it and its guid. `M.button(opts)` is the same idea against a record-shaped map applied through `Zin.map.activate`, in two flavors: - `{ action = "jump" }` attaches an extra touchButton binding to an existing action on the active map. - `{ emit = "KeyF", label = "Cast" }` registers an overlay-only button: a synthetic `emit:KeyF` action carrying both the kbm key binding and the touchButton, so the emulation floor drives `KeyF` through the same binding/emulation path every other control uses. Both return a handle for `M.removeButton(handle)`. ## Exports - `M.addControl(opts: ControlOpts) -> number` / `M.removeControl(handle) -> boolean` — add or release a control while the world runs. - `M.controls() -> { { handle, name, path } }` — every control `addControl` currently holds, in the order they were added. - `M.button(opts) -> number` / `M.removeButton(handle) -> boolean` — the button API described above. - `M.claimed() -> { number }` — the contact ids currently claimed by the stick, a button, or the drag zone. - `M.primaryClaimed() -> boolean` — whether an on-screen control owns the primary contact. `Zin.bindings` consults this so a thumb on the stick or the look area does not also fire whatever the world bound to left-click. - `M.layout() -> { buttons, fan?, stick?, drag?, pinch?, width, height, safe }` - the current control layout (a copy): `buttons` is the budgeted, VISIBLE stack in draw order, each entry `{ id, label, actionName, priority, size, appliedSize, group, cx, cy, radius }` in `ui.screenSize()` space — `size` is the step the binding declared and `appliedSize` the one `radius` came from, which differ only where a rich scheme's step-down moved a button one size down; `fan` is nil unless the button set exceeded the two-column budget, else `{ open, cx, cy, radius, buttons }` — `open` is whether the overflow sheet is expanded, `buttons` the overflowed entries at their sheet positions (tappable only while `open`); `stick` / `drag` name the axis + virtual zone each region feeds, and `pinch` the axis the two-finger recognizer feeds; `safe` is the safe rect `{ x, y, width, height }` every control keeps inside. Backs custom control-placement UI and headless tests that aim simulated touches at a button's (or the fan's) center. - `M._advance()` — internal: one tick (touch routing, layout, auto-mount, repaint). Wired into `Zin.tick`, before `Zin.emulation._advance()`. - `M._forceMount(on: boolean)` — test-only: force mounting regardless of `Zin.surface.current()`. - `M._setViewportOverride(w?, h?)` — test-only: override the logical screen size the layout budget/fan math reads, without resizing the real window. Pass nil/nil to clear. - `M._reset()` — test-only: unmount, clear routing/layout state, drop buttons, release every runtime control, close the fan, and clear the viewport override.

# utils Pure helpers for the `Zin` input library. Mouse-button name↔index conversion, key-code normalization, held-modifier matching against a frame snapshot, and the shaping a reading passes through on its way to a consumer. No FFI; safe to call from any context. Stateless. ## Exports - `M.buttonName(idx: number) -> string?` — convert a 0-based mouse button index to its name. - `M.buttonIndex(name: string) -> number?` — convert a mouse button name to its 0-based index. - `M.normalizeKey(code: string) -> string` — canonicalize a key code: a single ASCII letter becomes its `Key<L>` code, a single digit its `Digit<N>` code; multi-character codes pass through. - `M.matchModifiers(snapshot: Snapshot, mods: Modifiers) -> boolean` — test whether the snapshot's held keys match the requested modifier set. - `M.applyCurve(curve, x: number) -> number` — apply a response curve to a reading. - `M.applyDeadzoneScalar(x: number, deadzone: number?) -> number` — 0 below the threshold, the reading at or above it. - `M.applyDeadzoneVector(v: Vector2, deadzone: number?) -> Vector2` — the same, measured **radially** on the magnitude of the pair. - `M.shapeScalar(x: number, deadzone: number?, curve, invert: boolean?) -> number` — deadzone, then curve, then inversion. - `M.shapeVector(v: Vector2, deadzone: number?, curve, invert: boolean?) -> Vector2` — the same for a pair. - `M.smoothToward(current: number, target: number, dt: number, tau: number) -> number` — one step of an exponential approach with time constant `tau`. A `curve` is `"linear"`, `"quadratic"`, `"cubic"`, a function of the reading, or `nil` for linear. Types: - `Snapshot = { [string]: any }` — the raw frame-snapshot table returned by `Zin.state.get()`. - `Modifiers = { ctrl: boolean?, shift: boolean?, alt: boolean? }` — modifier subset to require in `matchModifiers`. - `Vector2 = { x: number, y: number }` — a two-component reading. ## Shaping The order is deadzone, curve, invert, then the approach toward the shaped target. A scalar takes its deadzone per value; a pair takes it radially, so a diagonal is not clipped into a cross by two independent thresholds. `"quadratic"` squares while keeping the sign, so a half-pushed stick reads a quarter in the direction it was pushed. A curve function that raises, or answers with anything other than a number, leaves the reading as it was. This is the one implementation of that shaping: `Zin.axes` reads it for a registered axis and `Zin.scheme` for an `axis1` / `axis2` control, so an axis and a control declaring the same numbers read the same. ## Usage ```luau local Utils = require("@builtin::modules.zinput.utils") local name = Utils.buttonName(0) -- "left" local idx = Utils.buttonIndex("right") -- 1 local key = Utils.normalizeKey("w") -- "KeyW" local hit = Utils.matchModifiers(snap, { ctrl = true, shift = false }) ``` ## Notes - Pure functions — no state, no side effects. - Mouse-button indexing is 0-based and matches `Zin.state.mouseButtonDown(idx)` (0=left, 1=right, 2=middle). - `matchModifiers` ignores fields set to `nil` in `mods` — only `true`/`false` are constraints. - `normalizeKey` rejects any other single character: no bound key code is one character long, so `"?"` raises rather than resolving to a phantom key nothing consumes.

# virtual Per-tick virtual-control values. On-screen controls (and tests) write stick vectors, button states, and drag deltas here; the `touchStick` / `touchButton` / `touchDrag` / `touchPinch` binding kinds in `Zin.bindings` read them. Backs `Zin.virtual`. Three families, each keyed by the control's binding identity: - **Sticks** — zone string (`"left"`, `"right"`, ...). A vector clamped to `[-1, 1]` per component, persisting until set again or reset. - **Buttons** — id string: a `touchButton`'s `id` (stamped with the control's name when its map activates), else its `label`, else its `zone`. A held boolean; `buttonPressed` / `buttonReleased` derive edges from the previous frame boundary. - **Drags** — zone string. A delta vector that accumulates within a tick (`addDrag` sums repeated calls) and clears at the next frame boundary — the same per-frame-delta semantics as `Zin.state.mouseDelta()`. ## Edge-at-frame-boundary semantics `_beginFrame()` shifts `_buttons` into `_buttonsPrev` and clears drag deltas. It runs once per engine frame from the `Zin.tick` coordinator's gated begin block, before any binding evals happen. On-screen overlay code (script phase) calls `setButton` earlier in the same frame it wants the press recognized; `buttonPressed` reads true starting the frame `_beginFrame` next observes the transition — matching how a real key's press edge surfaces on the frame after the OS event, not the same frame the write happened. ## Exports - `M.setStick(zone: string, x: number, y: number)` — set a stick's vector (clamped). - `M.stick(zone: string) -> (number, number)` — read a stick's `(x, y)`; `(0, 0)` when unset. - `M.setButton(id: string, held: boolean)` — set a button's held state. - `M.button(id: string) -> boolean` — held state. - `M.buttonPressed(id: string) -> boolean` — press edge this frame. - `M.buttonReleased(id: string) -> boolean` — release edge this frame. - `M.addDrag(zone: string, dx: number, dy: number)` — accumulate a drag delta. - `M.drag(zone: string) -> (number, number)` — read a zone's accumulated `(dx, dy)` this frame. - `M._beginFrame()` — internal: frame-boundary edge shift + drag clear, called by `Zin.tick`. - `M._reset()` — test-only: clear all virtual state. ## Usage ```luau local Virtual = require("@builtin::modules.zinput.virtual") Virtual.setStick("left", 0.4, -0.9) local x, y = Virtual.stick("left") Virtual.setButton("Jump", true) if Virtual.buttonPressed("Jump") then -- fires once, on the frame after the set end ```

# luau_introspect (module) Parses Luau/asset source TEXT into structured declarations. Pure string/pattern parsing (`string.find` / `string.match` / `string.gmatch`) over the literal source — no compiling, no VM spawn, no runtime state, no engine FFI. Given source text, it extracts what is written in the file. This is the shared parser every per-assetType `M.ref.inspect` hook uses to turn a component/module/tool's own source into the structured record `asset.inspect` returns. ## Exports - `docstrings(src) -> DocMap` — scans `--!desc` / `--!arg` / `--!return` / `--!example` comment runs and binds each run to the name of the declaration on the next non-comment line (the identifier after `function`, `public:`, `local function`, or `M.`). - `publicFields(src) -> { FieldEntry }` — parses `public = { name = Field.<kind>(default, mode), ... }` table-literal entries and module-scope `public.<name> = Field.<kind>(...)` assignments. - `events(src) -> { EventEntry }` — parses `events = { name = Event(payloadSchema?, syncMode?), ... }` table-literal entries. - `methods(src) -> { MethodEntry }` — parses `function public:<name>(...)` / `typed function public:<name>(...)` declarations (params + optional return type). - `lifecycleHooks(src, catalog) -> { string }` — top-level `function <name>(` declarations whose name is in the caller-supplied `catalog` array. - `moduleExports(src) -> { ExportEntry }` — parses `M.<name> = function` assignments, `function M.<name>(...)` declarations, and a trailing `return { foo = foo, ... }` export table. - `forSource(src, computeFn) -> any` — memoises `computeFn(src)` keyed on `src` itself in a module-local table. The same source text returns the cached result without re-running `computeFn`; different source text recomputes. Keyed on the source content (not an asset checksum) because composite/container assets (component folders, scene folders, etc.) all hash to the empty-string checksum — a checksum-keyed cache collapses every such asset's detail onto whichever one was inspected first. ## Usage ```luau local Introspect = require("modules.luau_introspect") local src = self:getInitScript() local detail = Introspect.forSource(src, function(s) return { fields = Introspect.publicFields(s), events = Introspect.events(s), methods = Introspect.methods(s), hooks = Introspect.lifecycleHooks(s, lifecycleCatalog), } end) ``` ## Notes - Every function is a pure string→table transform: same source text in, same structured table out, every time. No reads of live component state, no entity/world queries. - Structural scanning runs over a comment- and string-aware **mask** of the source (a same-length copy where comment bodies and string-literal contents are blanked to spaces, delimiters and newlines preserved). Pattern matches and brace/paren balancing run on the mask — so a brace, `Field.`, `Event(`, or a whole entry that appears inside a comment or a string literal never registers — while captured values are sliced from the original source at the same (aligned) indices. This makes the parser robust to apostrophes in comments, commented-out entries, string defaults containing `}` / `Field.` / `Event(`, and `[[ ]]` long strings. - `default` / `category` are raw trimmed source-text slices (with any trailing comment stripped), not evaluated values. - For a **ref constructor** (`Field.assetRef` / `dataRef` / `resource` / `componentRef`) the FIRST positional argument is the category / contract / componentType selector, captured under `category`; the SECOND argument is captured under `default`. - For every **other** Field kind the first argument is the `default` and `category` is nil. - A trailing `Sync` / `NoSync` identifier is captured as `sync`, tolerating a trailing comma or a trailing comment after the last argument. - Field/Event entries whose key is a computed or indirect expression (`[expr] = Field.number(...)`) are omitted — only literal identifier keys are recognised. - `methods` captures a `...` variadic parameter (as `name = "..."`), with its `: <type>` annotation when present. - A `--!desc` written above a field/event declaration (`<name> = Field.<kind>(...)` / `<name> = Event(...)`) or a `public.<name> =` assignment binds to that name in `docstrings`, and is folded into the corresponding `publicFields` / `events` entry's `desc`. - `lifecycleHooks` never hardcodes the lifecycle-callback catalog; the caller passes the list of names to match against. - `forSource`'s memo is bounded (oldest-key eviction) so a long session touching many distinct asset versions can't grow it without limit.

# assetType.shared.ref Builds the metatable every `AssetRef` (the `{ __ref, type, name, guid, identity, path }` envelope returned by `asset.resolve` / `asset.ref`) carries. Replaces the per-call C metatable that used to live in `crates/zero_scripting/src/ffi/bindings/asset.rs::attach_asset_ref_metatable`. ## Public API ```lua local assetRef = require("@builtin::assetTypes.assetType.shared.ref") -- Called by the Rust factory (push_asset_ref_handle) via -- _G.__build_asset_ref_proxy after the envelope fields are set. assetRef.build(envelope) -- attaches AssetRefMT, returns the table ``` The module exposes no invalidation surface — discovery is registry-driven and hot-reload is transparent (see "Discovery and hot-reload" below). ## Method dispatch order `ref.foo` is resolved in this order: 1. **Default methods** — `getSource` / `getBytes` / `getText` / `exists` / `inspect` and the lazy `meta` property. Per-type definitions cannot override these (engine contract from gh#1889). 2. **Per-type `ref` table** — discovered through `asset.resolve(<typename>, "assetType")` + `require(<identity>.behavior)`. The lookup resolves to whichever `<typename>.assetType/` folder is currently registered for the typename (built-in, user, or library-vendored) and pulls its `ref` methods. 3. **Nil** — unknown key, same shape as the original C metatable. ## Adding methods for a new asset type Drop a `behavior.luau` into the type folder: ``` src/lua/lib/assetTypes/<typename>.assetType/ ├── type.yaml -- structural spec (existing) ├── behavior.luau -- ref + global behaviour (new) └── template/ -- placeholder body (existing) ``` `behavior.luau` returns: ```lua return { ref = { --!desc Per-instance method on every `<typename>` AssetRef. myMethod = function(self, ...) ... end, }, global = { -- Reserved for the asset.<typename>.* surface — not consumed -- yet; included so the contract from gh#1889 lands cleanly. }, } ``` Within `ref` methods, `self` is the AssetRef envelope: `self.path`, `self.identity`, `self.guid`, `self.type`, `self.name` are available. Engine-required fields (`guid`, `path`, `identity`, `type`) must not be redefined. ## Discovery and hot-reload Type discovery uses the asset registry, so it doesn't matter where a `<typename>.assetType/` folder lives — engine built-ins under `@builtin::assetTypes.<X>`, user types dropped under `/zero/source/<X>.assetType/`, or types vendored inside an imported library all resolve identically. The dispatcher walks `asset.resolve(<typename>, "assetType")` → canonical identity → `require <identity>.behavior` on every miss; the asset registry is the cache for the resolve half and Luau's `_LOADED` is the cache for the require half. Hot-reload is transparent. When a `<typename>.assetType/behavior.luau` is rewritten through VFS, the engine's `invalidate_require_cache_for_state` re-runs the module and mutates the cached `_LOADED[<identity>.behavior]` table in place. Dispatch reads `mod.ref` on every access (rather than caching a sub-pointer), so existing AssetRefs see the new methods on the very next access — no Rust-side hook into this module is needed, and no invalidation API is exposed for callers to call. The same registry-driven path also handles type **registration** correctness: dropping a new `<typename>.assetType/behavior.luau` updates the asset registry, the next `asset.resolve(<typename>, "assetType")` returns the new ref, and AssetRefs of that type immediately gain the new methods. ## Why Luau, not Rust The asset surface needed per-category behaviour (`material:getProperties()`, `bundle:instantiate(entityId)`, `tool:run(args)`) and the old shape couldn't grow without an FFI change per method. Owning the proxy in Luau means: - Type-specific methods ship as content (the `<typename>.assetType/` folder), not engine code. - Adding a new asset type drops in a new folder; no Rust rebuild. - Methods can call any other Luau global (`vfs`, `asset`, `Material`, `entity`, etc.) directly, instead of going through narrow FFI primitives. ## Consumers - `crates/zero_scripting/src/ffi/bindings/asset.rs::attach_asset_ref_metatable` — the Rust factory that pushes envelopes invokes `_G.__build_asset_ref_proxy` once per push. - Every Luau call site of `asset.resolve` / `asset.ref` / `entity(id).component.X.material` / any binding declared `AssetRef<...>` — they all receive envelopes built through this module.

# yaml.module YAML decode + encode for authored engine content. Pure Luau, no engine dependencies — a general parsing library, not data-system plumbing. ```luau local Yaml = require("@builtin::modules.yaml") local doc = Yaml.decode(vfs.read(path)) vfs.write(path, Yaml.encode(doc)) ``` ## Supported subset - Block mappings (`key: value`) and block sequences (`- item`), nested to any depth. - Compact sequence-of-mapping entries (`- path: x` / ` kind: y`). - Flow collections — `{ a: 1, b: 2 }` and `[1, 2, 3]` — single line. - Plain scalars with type inference: `~` / `null` → nil, `true` / `false` → boolean, numeric literals → number, everything else → string. - Single- and double-quoted strings (`''` escapes a literal quote inside a single-quoted string; `\n` `\t` `\r` `\\` `\"` inside a double-quoted one). A quote opens a quoted scalar where a scalar begins — after `key:`, after a `- ` entry marker, or inside a flow collection — so a plain scalar carries an apostrophe as data (`note: the world's rules`). Quoted keys are read in flow mappings. - `#` comments — honored outside quotes, so a `#` inside a quoted string is kept as data. - Literal (`|`) and folded (`>`) block scalars — the bare indicators only. A block scalar's content is literal text: quotes (balanced or not), `#`, `key: value` and `---` inside it are data. - An optional leading `---` document marker. ## Loud-error contract Constructs outside the subset above raise instead of misparsing: anchors/aliases (`&`, `*`), tags (`!`), directives (`%`), multi-document streams (a second `---`), block-scalar chomping/indentation indicators (`|-`, `|+`, `>-`, `|2`, ...), tab indentation, and inconsistent indentation (both block structure and block-scalar bodies). Every error carries the offending line number (`yaml: line N: ...`), so a bad config points straight at the line to fix. Tab indentation is rejected everywhere — including block-scalar body lines whose leading whitespace contains a tab. A tab after the first non-space character of a line is content and passes through. ## API - `Yaml.decode(text: string): any` — decode a YAML document into a Luau value (table, scalar, or nil for an empty document). Raises on malformed input or an unsupported construct. - `Yaml.decodeWithComments(text: string): (any, boolean)` — decode as `decode` does, and report whether the text carries a comment by the decoder's own rule: a `#` at a line's start or after whitespace, outside a quoted scalar and outside a block scalar. Re-encoding the value drops such comments, so an editor that writes a document back reads this first. - `Yaml.encode(value: table): string` — encode a Luau table as YAML (block style, two-space indent, alphabetically sorted keys). Raises on values YAML can't represent (functions, userdata, non-string mapping keys). A top-level empty table encodes to an empty document, which decodes back to `nil` (the YAML empty-document ambiguity).

# json JSON encode/decode library for Luau. Encodes Lua values to JSON strings and decodes JSON strings back to Lua values. Used for communication with the Rust side of the engine, the VFS read/write bridge, and any wire-format that needs JSON. Pure Luau, no engine dependencies. Compact and pretty-printed encoders, plus a hand-rolled decoder that streams the input by position so it works under WASM as well as native. ## Exports - `Json.encode(value: any, indent?: string, currentIndent?: string) -> string` — compact encode. Functions / unknown types and NaN/Inf encode as `null`. - `Json.encodePretty(value: any, indentStr?: string) -> string` — pretty-printed encode with sorted object keys (diff-friendly). - `Json.encodeArgs(...: any) -> string` — encode varargs as a JSON array. - `Json.decode(str: string) -> any` — decode a JSON string. Returns the decoded value, or `nil` + error message on failure. ## Usage ```luau local Json = require("@builtin::modules.json") local widget = { type = "button", text = "Click Me" } local compact = Json.encode(widget) -- '{"text":"Click Me","type":"button"}' local pretty = Json.encodePretty(widget, " ") local decoded = Json.decode(compact) local v, err = Json.decode("oops") -- v = nil, err = error message ``` ## Notes - Object keys are sorted alphabetically in both encoders for consistent output across runs. - Numeric keys on objects are stringified at encode time (JSON has no numeric keys). Pure-integer key sets get detected as arrays via `isArray` and encoded with brackets. - NaN, +Inf, -Inf encode as `null` — JSON has no representation. Round trips through `decode` recover `null` (Lua `nil`), so they don't preserve. - Unicode `\uXXXX` escapes decode to UTF-8 by hand to stay WASM-safe. Only the BMP is covered; supplementary planes via surrogate pairs are not. - Functions encode as `null`. - Decode is character-streamed — no regex, no `string.match` patterns on the whole input — so the line-and-column information needs to be reconstructed from the position offset.

# assetType runtime The machinery that reads a `<typename>.assetType/behavior.luau` and turns its declarations into live behaviour. A `behavior.luau` is a table of declarations — `ref` methods, `modules` shared code, an `events` schema, a `namePattern`, `refShapes`, and the `onCreate` / `onRegister` / `onChange` / `onDelete` / `validate` / `settingsDefaults` / `settingsCorrections` hooks. None of it runs itself. This is the code that runs it, and it lives here because reading a type's declarations is the **assetType type's own behaviour** — the same way `material.assetType` owns what a `.material` does. ## Sub-modules | Module | Reads | Responsibility | |---|---|---| | `ref.module` | `ref`, `modules` | Builds every `AssetRef` envelope, attaches the shared metatable, and dispatches per-type methods and shared modules onto it. Also owns edit-mode write-behind persistence. | | `create.module` | `onCreate`, `namePattern`, `validate` | Backs `asset.create`: resolves the type, checks the name against its pattern, runs `onCreate` (or clones `template/`), and writes the instance. `validate.module` beside it checks a creation `opts` table against the type's `createSchema`. Before running `onCreate`, resolves the type's settings chain (below) and hands the result to the hook as `opts.settings`. | | `settings.module` | `settings`, `settingsDefaults`, `settingsCorrections` | A type's declared settings schema and where its values live (`type.yaml`'s `settings:` block). `Settings.resolveForCreate` layers the schema's own defaults, the type's own `settingsDefaults(name, opts, asked)` hook (a DEFAULT the schema can't express — a name-derived convention, a fact read off a payload the caller handed it, a value following a field `asked` shows a higher layer naming; any later layer overrides it), the Preset Manager, an importer's settings, the caller's `settings` table, then the type's own `settingsCorrections(values, name, opts)` hook (a CROSS-FIELD CONSTRAINT the schema can't express, applied last over the fully merged values). A correction over a default/preset/importer value lands silently; a correction that would override what the caller's own `settings` table explicitly asked for refuses the creation instead, naming the field and why. Neither hook is ever handed a table to mutate; each returns what it wants changed (`settingsCorrections` may also return a `{ [field]: reason }` table for that refusal message). `Settings.cloneValues` deep-copies a values table — `create.module` hands `onCreate` a copy, never the table it stamps. `Settings.valuesOf` / `writeValues` read and write an asset's own values file. | | `typeYaml.module` | `type.yaml` | The folder a type lives in and its parsed `type.yaml`, decoded once per content version of the file. `settings.module` and `inspector.module` read their blocks through it. `about` / `aboutAt` read a type's `about.yaml` (`intent`, `function`, `usage`), leaving out any key that is empty or still starts with `[[describe]]`; `aboutRows` and `aboutMarkdown` lay the texts out for the Inspector and the `types/<name>` guide. | | `inspector.module` | `type.yaml`'s `inspector:` block | Which inspector a type declares for its assets (`inspector: { type: ... }` or `{ instance: ... }`), and the declaration that file returns — the sections it adds, the generic ones it replaces, and their order — or the problem that kept it from loading. | | `onRegister.module` | `onRegister` | Fires an instance's once-only registration hook — on arrival, on world load, and for `@builtin` library instances. | | `changeDispatch.module` | `onChange`, `onDelete`, `refShapes` | Routes a VFS source write or a folder delete to the enclosing typed asset's type hooks. | | `refShapes.module` | `refShapes`, `ref` | Publishes what every `AssetRef<category>` answers to, so a member read on an asset-typed value is checked against that category's real surface. | | `events.module` | `events` | The per-asset event runtime behind `ref.events`. | | `instantiable.module` | `ref.instantiate` | The instantiation contract an asset type opts into: `root` stands the root entity, `place` applies the base placement opts to one the type adopted, and `result` shapes the `(root, idMap)` every `instantiate` returns. Also registers the `sceneInstantiable` field-constraint validator. | | `declaration.module` | `type.yaml` | The type's decoded declaration, read once and held until a write inside an `.assetType` folder; what every question about a type as a whole reads. | | `previewRecipe.module` | `type.yaml` `preview:` | How an instance's `preview.png` is produced: which of the four recipes (`instantiate`, `image`, `surface`, `custom`) the type declares, and what that recipe needs. | ## Reaching it ```luau local rt = require("@builtin::assetTypes.assetType.shared") rt.ref.loadTypeBehavior("material") ``` Fields resolve lazily. The prelude requires the sub-modules directly, in dependency order (`ref`, then `changeDispatch`, `onRegister.install()`, `refShapes.install()`) — a table that required all six on load would take that ordering away from it.