Transform

Own fields and getters the Inspector leaves out of this component’s reflected state. Use it for bulk data that is not worth a diagnostic copy — a parsed tilemap, a large lookup table. Lists merge down the class chain, so a subclass adds to its base class’s exclusions.

class TilemapComponent extends VisualComponent {
  static inspectExclude = ["data"];
}

Inherited from

Component.inspectExclude

updatePriority?

static optional updatePriority?: number

Defined in: Component.ts:448

Class-level default for updatePriority: every instance runs at this priority unless its own updatePriority is written. Undeclared = 0. Subclasses inherit their base class’s value unless they declare their own. Declare it on a component whose behavior depends on running after (or before) a sibling, so the entity that adds it does not have to control the add order.

class BoundsClamp extends Component {
  static updatePriority = 10; // after the follow that moves the camera
}

Inherited from

Component.updatePriority

Accessors

context

Get Signature

get context(): EngineContext

Defined in: Component.ts:114

Access the EngineContext from the entity’s scene. Throws if the entity is not in a scene.

Returns

EngineContext

Inherited from

Component.context

effectiveEnabled

Get Signature

get effectiveEnabled(): boolean

Defined in: Component.ts:61

Whether the component is actually running: enabled, on an active entity, and past onAdd. This is the state onEnable and onDisable track — read it when a method has to behave one way live and another way dormant.

Returns

boolean

Inherited from

Component.effectiveEnabled

enabled

Get Signature

get enabled(): boolean

Defined in: Component.ts:45

Whether this component runs. Disabled components are skipped by ComponentUpdateSystem.

Writing this fires onEnable / onDisable when the effective state changes — enabled && entity.isActive. A component disabled here stays disabled through a setActive(false) / setActive(true) cycle on its entity.

Returns

boolean

Set Signature

set enabled(value): void

Defined in: Component.ts:49

Parameters

value

boolean

Returns

void

Inherited from

KeyframeAnimator.enabled

position

Get Signature

get position(): Vec2

Defined in: Transform.ts:75

Local position (relative to parent, or world if no parent).

Returns

Vec2

Set Signature

set position(v): void

Defined in: Transform.ts:79

Parameters

v

Vec2

Returns

void

rotation

Get Signature

get rotation(): number

Defined in: Transform.ts:89

Local rotation in radians.

Returns

number

Set Signature

set rotation(v): void

Defined in: Transform.ts:93

Parameters

v

number

Returns

void

scale

Get Signature

get scale(): Vec2

Defined in: Transform.ts:100

Local scale factor.

Returns

Vec2

Set Signature

set scale(v): void

Defined in: Transform.ts:104

Parameters

v

Vec2

Returns

void

scene

Get Signature

get scene(): Scene

Defined in: Component.ts:100

Access the entity’s scene. Throws if the entity is not in a scene. Prefer this over threading through this.entity.scene in component code.

Returns

Scene

Inherited from

Component.scene

updatePriority

Get Signature

get updatePriority(): number

Defined in: Component.ts:82

Where this component runs among its siblings. ComponentUpdateSystem calls update / fixedUpdate on an entity’s components in ascending priority; equal priorities run in add order. Undeclared = 0, so a negative value runs before siblings that keep the default and a positive value runs after them. Writable at any time, before or after add(). Defaults to the class’s static updatePriority.

class Player extends Entity {
  setup() {
    this.add(new Mover());
    this.add(new Brain()).updatePriority = -1; // decides before Mover moves
  }
}

Returns

number

Set Signature

set updatePriority(value): void

Defined in: Component.ts:90

Parameters

value

number

Returns

void

Inherited from

KeyframeAnimator.updatePriority

worldPosition

Get Signature

get worldPosition(): Vec2

Defined in: Transform.ts:114

Computed world position. Recomputed lazily when dirty.

Returns

Vec2

Set Signature

set worldPosition(v): void

Defined in: Transform.ts:129

Set position in world space. Back-computes the local position from the parent chain. On an axis where the parent’s world scale is 0 no local value can reach the requested world value, so the local value on that axis is kept unchanged (and a dev-mode warning is emitted).

Parameters

v

Vec2

Returns

void

worldRotation

Get Signature

get worldRotation(): number

Defined in: Transform.ts:182

Computed world rotation. Recomputed lazily when dirty.

Returns

number

Set Signature

set worldRotation(v): void

Defined in: Transform.ts:188

Set rotation in world space. Back-computes the local rotation from the parent chain.

Parameters

v

number

Returns

void

worldScale

Get Signature

get worldScale(): Vec2

Defined in: Transform.ts:204

Computed world scale. Recomputed lazily when dirty.

Returns

Vec2

Methods

_applyEnabled()

_applyEnabled(effective): void

Defined in: Component.ts:376

Internal

Force an effective-enabled transition, firing the hook on a flip. Used by Entity for teardown, where enabled and the entity’s activeness both still read true.

Parameters

effective

boolean

Returns

void

Inherited from

Component._applyEnabled

_isTornDown()

_isTornDown(): boolean

Defined in: Component.ts:347

Internal

Internal: true once this component has been removed or its entity destroyed. Components are terminal — Entity.add uses this to reject re-attaching an instance whose cleanups and onDestroy already ran.

Returns

boolean

Inherited from

Component._isTornDown

_markDirty()

_markDirty(): void

Defined in: Transform.ts:335

Internal

Mark this transform and all descendant transforms as dirty.

Returns

void

_markTornDown()

_markTornDown(): void

Defined in: Component.ts:356

Internal

Internal: mark this component torn down. Called by Entity.remove() and Entity._performDestroy() after onDestroy runs.

Returns

void

Inherited from

Component._markTornDown

_refreshEnabled()

_refreshEnabled(): void

Defined in: Component.ts:365

Internal

Recompute effective enabled-ness from enabled and the entity’s activeness, firing the hook on a flip.

Returns

void

Inherited from

Component._refreshEnabled

_runCleanups()

_runCleanups(onError?): void

Defined in: Component.ts:319

Internal

Run and clear all registered cleanups. Called by Entity.remove() and Entity._performDestroy() before onDestroy.

Parameters

onError?

(error) => void

Returns

void

Inherited from

Component._runCleanups

addCleanup()

protected addCleanup(fn): void

Defined in: Component.ts:277

Register a cleanup function to run when this component is removed or destroyed, before onDestroy. Use it for what listen, listenScene and listenBus do not cover, such as an unsubscribe from a custom emitter.

Parameters

fn

() => void

Returns

void

Inherited from

Component.addCleanup

destroy()

destroy(): void

Defined in: Component.ts:335

End this component’s life on its own — the same as entity.remove(SomeClass), without having to name its own class from inside itself, which breaks under subclassing.

Returns

void

Inherited from

Component.destroy

fixedUpdate()?

optional fixedUpdate(dt): void

Defined in: Component.ts:432

Called every fixed timestep by the built-in ComponentUpdateSystem.

Parameters

dt

number

Fixed timestep in seconds, scaled by scene and entity timeScale.

Returns

void

Inherited from

Component.fixedUpdate

getPositionInto()

getPositionInto(out): Vec2Buffer

Defined in: Transform.ts:214

Copy local coordinates into caller-owned scratch.

Parameters

out

Vec2Buffer

Returns

Vec2Buffer

getScaleInto()

getScaleInto(out): Vec2Buffer

Defined in: Transform.ts:225

Copy local scale into caller-owned scratch.

Parameters

out

Vec2Buffer

Returns

Vec2Buffer

getWorldPositionInto()

getWorldPositionInto(out): Vec2Buffer

Defined in: Transform.ts:219

Copy world coordinates into caller-owned scratch.

Parameters

out

Vec2Buffer

Returns

Vec2Buffer

getWorldScaleInto()

getWorldScaleInto(out): Vec2Buffer

Defined in: Transform.ts:230

Copy composed world scale into caller-owned scratch.

Parameters

out

Vec2Buffer

Returns

Vec2Buffer

listen()

protected listen<T>(source, token, handler): void

Defined in: Component.ts:237

Subscribe to events from an entity or a state machine, auto-unsubscribe on removal.

this.listen(this.entity, Hurt, ({ dir }) => this.knockback(dir));
this.listen(brain.mode, brain.mode.events.entered, ({ state }) =>
  this.anim.play(state),
);

Type Parameters

T

T

Parameters

source

EventSource

token

EventToken<T>

handler

(data) => void

Returns

void

Inherited from

Component.listen

listenBus()

protected listenBus<K>(event, handler): void

Defined in: Component.ts:263

Subscribe to an engine EventBus event, auto-unsubscribe on removal. Throws when the entity is not in a scene, like listenScene.

Type Parameters

K

K extends keyof EngineEvents

Parameters

event

K

handler

(data) => void

Returns

void

Inherited from

Component.listenBus

listenScene()

protected listenScene<T>(token, handler): void

Defined in: Component.ts:251

Subscribe to scene-level events, auto-unsubscribe on removal. Handlers fire for bubbled entity events (entity = source) and scene.emit events (entity = undefined).

Type Parameters

T

T

Parameters

token

EventToken<T>

handler

(data, entity?) => void

Returns

void

Inherited from

Component.listenScene

localToWorld()

localToWorld(point): Vec2

Defined in: Transform.ts:297

A point in this entity’s own space, expressed in world space.

The point is scaled by the world scale, turned by the world rotation, and offset by the world position — the same composition a child transform goes through — so an offset authored beside the entity lands where the artwork does whatever the parent chain does.

const muzzle = this.get(Transform).localToWorld({ x: 24, y: -6 });

Parameters

point

Vec2Like

Returns

Vec2

onAdd()?

optional onAdd(): void

Defined in: Component.ts:398

Called when the component is added to an entity. Validate dependencies here — a service, a sibling component, a render layer — and throw when one is missing. The throw is attributed to this component, recorded in Inspector.getErrors().callbackErrors, and rethrown, so it reaches the caller of entity.add() unchanged.

Returns

void

Inherited from

Component.onAdd

onDestroy()?

optional onDestroy(): void

Defined in: Component.ts:420

Called when the component is destroyed (entity destroyed or component removed).

Returns

void

Inherited from

Component.onDestroy

onDisable()?

optional onDisable(): void

Defined in: Component.ts:417

Called when the component stops being effectively enabled — enabled went false, the entity (or an ancestor) was deactivated, or the component is being removed or destroyed. Put live resources to sleep here; the component is reused afterwards, so do not free anything onEnable cannot rebuild.

Returns

void

Inherited from

Component.onDisable

onEnable()?

optional onEnable(): void

Defined in: Component.ts:408

Called when the component becomes effectively enabled — enabled is true and the entity is active. Fires right after onAdd() for a component added to an active entity, and again on every later flip. Bring live resources back online here (unpause a sound, show a display object, re-enable a physics body). Game-state reset does not belong here: the hook sees whatever state the component held while dormant.

Returns

void

Inherited from

Component.onEnable

rotate()

rotate(deltaRadians): void

Defined in: Transform.ts:265

Rotate by a delta in radians.

Parameters

deltaRadians

number

Returns

void

service()

protected service<T>(key): T

Defined in: Component.ts:177

Lazy proxy-based service resolution. Can be used at field-declaration time:

readonly input = this.service(InputManagerKey);

The actual resolution is deferred until first property access.

Type Parameters

T

T extends object

Parameters

key

ServiceKey<T>

Returns

T

Inherited from

Component.service

setPosition()

setPosition(x, y): void

Defined in: Transform.ts:236

Set position directly.

Parameters

x

number

y

number

Returns

void

setRotation()

setRotation(radians): void

Defined in: Transform.ts:258

Set rotation in radians.

Parameters

radians

number

Returns

void

setScale()

setScale(x, y): void

Defined in: Transform.ts:276

Set scale.

Parameters

x

number

y

number

Returns

void

setWorldPosition()

setWorldPosition(x, y): void

Defined in: Transform.ts:134

Set world coordinates without constructing a vector.

Parameters

x

number

y

number

Returns

void

sibling()

protected sibling<C>(cls): C

Defined in: Component.ts:205

Lazy proxy-based sibling component resolution. Can be used at field-declaration time:

readonly anim = this.sibling(AnimatedSpriteComponent);

The actual resolution is deferred until first property access. The reference passes instanceof cls before it resolves, so an engine API that checks the type of what it is handed (camera.follow(this.transform)) accepts it.

Type Parameters

C

C extends Component

Parameters

cls

ComponentClass<C>

Returns

C

Inherited from

Component.sibling

stateMachine()

protected stateMachine<S>(states, initial, options?): StateMachine<S>

Defined in: Component.ts:287

Create a state machine whose hooks and event handlers are attributed to this component when they throw. The machine can be declared as a field because service lookup waits until a hook runs.

Type Parameters

S

S extends string

Parameters

states

StateDefinitions<S>

initial

NoInfer<S>

translate()

translate(dx, dy): void

Defined in: Transform.ts:246

Translate by an offset.

Parameters

dx

number

dy

number

Returns

void

update()?

optional update(dt): void

Defined in: Component.ts:426

Called every frame by the built-in ComponentUpdateSystem.

Parameters

dt

number

Frame delta in seconds, scaled by scene and entity timeScale.

Returns

void

Inherited from

Component.update

use()

protected use<T>(key): T

Defined in: Component.ts:125

Resolve a service by key, cached after first lookup. Scene-scoped values (registered via scene._registerScoped) take precedence over engine scope. A key declared with scope: "scene" that falls back to engine scope emits a one-shot dev warning — almost always signals a missed beforeEnter hook.

Type Parameters

T

T

Parameters

key

ServiceKey<T>

Returns

T

Inherited from

Component.use

worldToLocal()

worldToLocal(point): Vec2

Defined in: Transform.ts:319

Convert a world-space point into this entity’s own local space — the inverse of this transform’s world position, rotation and scale. Use it to ask where a world point falls inside an entity that is parented, rotated or scaled.

On an axis whose world scale is 0 the world transform collapses that axis, so no local point maps back and the result is non-finite there. A caller that can be handed such a transform checks Number.isFinite.

Parameters

point

Vec2Like

Returns

Vec2

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