Behaviour

Since 0.6

The base of a behaviour written as a class.

P is the shape of its props (the script component's props); the fields a class declares take props of the same name. ts import { Behaviour, turnTowards, yawTo } from "@argus/gameplay" import type { EntityHandle } from "@argus/api" export default class Turret extends Behaviour { turnRate = 2 // rad/s; props.turnRate overrides it target: EntityHandle | null = null Start() { this.target = this.world.find("player") } Update(dt: number) { if (this.target) this.entity.yaw = turnTowards(this.entity.yaw, yawTo(this.entity, this.target), this.turnRate * dt) } OnTriggerEnter(other: EntityHandle) { if (other.hasTag("player")) this.events.emit("spotted") } }

Signature

export class Behaviour<P extends Record<string, any> = Record<string, any>> {
  constructor()
  Start?(): void
  Update?(dt: number): void
  OnPausedUpdate?(dt: number): void
  OnEnable?(): void
  OnDisable?(): void
  OnDestroy?(): void
  OnTriggerEnter?(other: EntityHandle): void
  OnTriggerExit?(other: EntityHandle): void
  OnCollisionEnter?(collision: Collision): void
  OnEvent?(event: GameEvent): void
  declare Awake?: "Awake is never called: use a field initialiser, or Start()"
  declare FixedUpdate?: "FixedUpdate is never called: Update(dt) runs every fixed 60 Hz tick, which is the fixed-step update other engines call FixedUpdate"
  declare LateUpdate?: "LateUpdate is never called: there is one fixed tick; do it in Update(dt)"
  declare OnTriggerStay?: "OnTriggerStay is never called: use OnTriggerEnter/OnTriggerExit and a field"
  declare OnCollisionStay?: "OnCollisionStay is never called: contacts report their start (OnCollisionEnter); keep a field"
  declare OnCollisionExit?: "OnCollisionExit is never called: contacts report their start (OnCollisionEnter); keep a field"
  declare update?: "a Behaviour class's hooks use the usual names: Update(dt), Start(), OnDestroy()"
  declare init?: "a Behaviour class's hooks use the usual names: Start(), or a field initialiser"
  get ctx(): Ctx<Record<string, any>, P>
  get entity(): EntityHandle
  get world(): WorldQuery
  get body(): RigidBody | null
  get controller(): Controller | null
  get input(): InputState | null
  get animator(): Animator | null
  get nav(): NavAgent | null
  get events(): EventBus
  get time(): TimeInfo
  get camera(): CameraHandle
  get audio(): AudioHandle
  get particles(): ParticlesHandle
  get labels(): LabelsHandle
  get render(): RenderHandle
  get ui(): UiHandle
  get hud(): HudHandle
  get session(): SessionHandle
  get save(): SaveHandle
  get files(): FilesHandle
  get props(): Readonly<P>
  log(message: string, data?: unknown): void
  get enabled(): boolean
  set enabled(on: boolean)
  static init(this: new () => Behaviour<any>, ctx: Ctx): void
  static update(ctx: Ctx, dt: number): void
  static pausedUpdate(ctx: Ctx, dt: number): void
  static dispose(ctx: Ctx, reason?: "detach" | "reload"): void
  static onTriggerEnter(ctx: Ctx, other: EntityHandle): void
  static onTriggerExit(ctx: Ctx, other: EntityHandle): void
  static onCollision(ctx: Ctx, collision: Collision): void
  static onEvent(ctx: Ctx, event: GameEvent): void
}

Import: import { Behaviour } from "@argus/gameplay"

Members

Member	Signature	Description
`constructor`	`constructor()`
`Start`	`Start?(): void`	Once, at the top of the first tick after the behaviour attached (after every field initialiser).
`Update`	`Update?(dt: number): void`	Every fixed 60 Hz tick while enabled — the fixed-step update (`FixedUpdate` in some engines); `dt` is 1/60 s.
`OnPausedUpdate`	`OnPausedUpdate?(dt: number): void`	Every tick while the world is held (a pause menu, `ctx.session.pause()`), in place of `Update`.
`OnEnable`	`OnEnable?(): void`	When the behaviour attaches or is re-enabled, and after a hot reload.
`OnDisable`	`OnDisable?(): void`	When it is disabled, detached, or about to be hot-reloaded.
`OnDestroy`	`OnDestroy?(): void`	When the entity (or the scene) is going. Not for a hot reload.
`OnTriggerEnter`	`OnTriggerEnter?(other: EntityHandle): void`	Something entered a trigger this entity takes part in; `other` is the other participant.
`OnTriggerExit`	`OnTriggerExit?(other: EntityHandle): void`	The other participant left.
`OnCollisionEnter`	`OnCollisionEnter?(collision: Collision): void`	A contact started.
`OnEvent`	`OnEvent?(event: GameEvent): void`	Any `emit`, from any behaviour or the app.
`Awake`	`declare Awake?: "Awake is never called: use a field initialiser, or Start()"`	Names Behaviour never calls: declared so that writing one is a type error whose message is the fix.
`FixedUpdate`	`declare FixedUpdate?: "FixedUpdate is never called: Update(dt) runs every fixed 60 Hz tick, which is the fixed-step update other engines call FixedUpdate"`
`LateUpdate`	`declare LateUpdate?: "LateUpdate is never called: there is one fixed tick; do it in Update(dt)"`
`OnTriggerStay`	`declare OnTriggerStay?: "OnTriggerStay is never called: use OnTriggerEnter/OnTriggerExit and a field"`
`OnCollisionStay`	`declare OnCollisionStay?: "OnCollisionStay is never called: contacts report their start (OnCollisionEnter); keep a field"`
`OnCollisionExit`	`declare OnCollisionExit?: "OnCollisionExit is never called: contacts report their start (OnCollisionEnter); keep a field"`
`update`	`declare update?: "a Behaviour class's hooks use the usual names: Update(dt), Start(), OnDestroy()" · static update(ctx: Ctx, dt: number): void`
`init`	`declare init?: "a Behaviour class's hooks use the usual names: Start(), or a field initialiser" · static init(this: new () => Behaviour<any>, ctx: Ctx): void`
`ctx`	`get ctx(): Ctx<Record<string, any>, P>`	The whole Argus ctx, for what has no handle here.
`entity`	`get entity(): EntityHandle`	This entity. Space is Argus's: `position` (local), `worldPosition`, `yaw` (radians), `forward` (-Z).
`world`	`get world(): WorldQuery`
`body`	`get body(): RigidBody \| null`
`controller`	`get controller(): Controller \| null`
`input`	`get input(): InputState \| null`
`animator`	`get animator(): Animator \| null`
`nav`	`get nav(): NavAgent \| null`
`events`	`get events(): EventBus`
`time`	`get time(): TimeInfo`
`camera`	`get camera(): CameraHandle`
`audio`	`get audio(): AudioHandle`
`particles`	`get particles(): ParticlesHandle`
`labels`	`get labels(): LabelsHandle`
`render`	`get render(): RenderHandle`	`ctx.render`: shader parameter writes (`setShaderParam`, `setMaterialParam`).
`ui`	`get ui(): UiHandle`
`hud`	`get hud(): HudHandle`
`session`	`get session(): SessionHandle`
`save`	`get save(): SaveHandle`
`files`	`get files(): FilesHandle`	The project's files under `data/`, read-only (`ctx.files`).
`props`	`get props(): Readonly<P>`	The script component's props, read-only (fields of the same name already hold them).
`log`	`log(message: string, data?: unknown): void`	A structured log line.
`enabled`	`get enabled(): boolean · set enabled(on: boolean)`	Whether `Update` runs. Setting it runs `OnEnable` / `OnDisable`, as in other engines.
`pausedUpdate`	`static pausedUpdate(ctx: Ctx, dt: number): void`
`dispose`	`static dispose(ctx: Ctx, reason?: "detach" \| "reload"): void`
`onTriggerEnter`	`static onTriggerEnter(ctx: Ctx, other: EntityHandle): void`
`onTriggerExit`	`static onTriggerExit(ctx: Ctx, other: EntityHandle): void`
`onCollision`	`static onCollision(ctx: Ctx, collision: Collision): void`
`onEvent`	`static onEvent(ctx: Ctx, event: GameEvent): void`