raea/app

raea/app is Bevy's App in TypeScript. A video registers its compositions here (registerRoot, <Composition>). A game or tool written as an App adds plugins with definePlugin and systems in Bevy's schedules (Startup, Update, FixedUpdate and the rest, exported by name), and BevyApp opens a headless App you can step frame by frame from a script or a test.

import { BevyApp, Startup, Update, definePlugin } from "raea/app";

let n = 0;
const Counter = definePlugin({
  name: "counter",
  build(app) {
    app.addSystems(Startup, () => { n = 0; });
    app.addSystems(Update, () => { n += 1; });
  },
});

const app = BevyApp.open({ plugins: [] }).addPlugins(Counter);
app.step(10);

import { App, BevyApp, clearRegistry, Composition } from "raea/app"

raea/app exports 1 component, 4 functions, 3 classes, 17 values, 8 types. Bevy's counterpart: bevy_app. Source: sdk/raea/src/app.ts.

#Components

#Composition

Declares a composition inside the root. It draws nothing itself; a renderer finds it through registerRoot.

#Functions

#clearRegistry

Forgets the registered root and its compositions (for tests; exported from the test entry only).

function clearRegistry(): void

#definePlugin

A TypeScript plugin: definePlugin({ name: "hud", build(app) { app.addSystems(Update,...) } }).

function definePlugin(p: Plugin): Plugin

#getCompositions

The compositions the registered root declares, in order.

function getCompositions(): RegisteredComposition[]

#registerRoot

Names the root component the renderer starts from, and records its compositions. Call it once.

function registerRoot(given: ReactElement<unknown, string | JSXElementConstructor<any>> | ComponentType): void

#Classes

#App

A headless Bevy App driven from TypeScript through Bevy's remote protocol: open it with its plugins, then spawn, insert, query and step it, and add TypeScript systems to its schedules.

#BevyApp

A headless Bevy App driven from TypeScript through Bevy's remote protocol: open it with its plugins, then spawn, insert, query and step it, and add TypeScript systems to its schedules.

#PluginGroup

Plugins added together, as Bevy's PluginGroup: group.set(p) replaces the member of p's name, disable(name) leaves one out, and the App adds the rest in order.

#Values

#conditions

Bevy's common run conditions (bevy_ecs::schedule::common_conditions, bevy_state's in_state, bevy_time's on_timer), as Conditions for system(..., { when }) and configureSet. Each call makes a fresh condition with its own memory (runOnce, resourceChanged, onTimer).

#First

The frame's schedules, in the order Bevy runs them (with StateTransition and the fixed step's inside).

#FixedFirst

The fixed step's schedules, run once a frame at the clock's step.

#FixedLast

#FixedPostUpdate

#FixedPreUpdate

#FixedUpdate

#Last

#PostStartup

#PostUpdate

#PreStartup

Bevy's schedules by their labels, for app.addSystems(Update,...) as in Rust.

#PreUpdate

#RunFixedMainLoop

#SpawnScene

#Startup

#StateTransition

#Update

The frame's main schedules: Update for game logic, then SpawnScene, PostUpdate and Last.

#Types

#CompositionProps

The props of Composition, tabled there.

#Condition

A run condition: asked on the frame's World before a system or set runs; false skips it this frame.

type Condition = (app: BevyApp, frame: number) => boolean

#Edit

A hand edit: segments are the composition's own frame ranges, [from, to), played one after another, so a trim, a split, a cut word or a moved span is a change to this list; the length becomes their sum.

#OpenOptions

#Plugin

A plugin written in TypeScript, as bevy_app's Plugin trait: build adds its systems, resources, observers and states to the App; once every plugin is built, each one's finish runs, then each one's cleanup, as App::run does. Unique by name unless isUnique is false (Bevy panics on a unique plugin added twice; this throws).

#PluginRef

A plugin of any author: a Rust plugin in raea's plugin build by its declared name (package.json raea.plugins: "avian", or a half: "lightyear_server") or by its generated handles (avian from avian.gen.tsx, which carries plugin: "avian"), a TypeScript Plugin, or a group of them.

type PluginRef = string | { readonly plugin: string } | Plugin | PluginGroup

#RegisteredComposition

#SystemOptions