Class: ActiveSystem

Top-down DFS: activeInHierarchy = parent.activeInHierarchy && self.active. Other systems gate on this so disabling an entity hides its whole subtree. The same walk derives underCanvas (has a Canvas on itself or an ancestor) for the 2D-renders-only-in-a-Canvas rule.

Skips the walk when nothing changed since last frame — checked via the dirty flag on each ActiveComponent (set by the auto-dirty setter when .active flips) plus a subscription to ActiveComponent adds. With a 50k-entity tree whose active never flips, the steady-state cost drops from a recursive DFS to a single linear scan of dirty bits.

Extends

• System

Constructors

Constructor

new ActiveSystem(): ActiveSystem;

Returns

ActiveSystem

Inherited from

System.constructor

Properties

Property	Modifier	Type	Default value	Inherited from
enabled	public	boolean	true	System.enabled
parallel	public	boolean	false	System.parallel

Methods

GetName()

GetName(): string;

Returns

string

Overrides

System.GetName

---

GetOrder()

GetOrder(): SystemOrder;

Returns

SystemOrder

---

GetPhase()

GetPhase(): SystemPhase;

Returns

SystemPhase

Overrides

System.GetPhase

---

OnClose()

OnClose(): void;

Returns

void

Inherited from

System.OnClose

---

OnInit()

OnInit(_engine): void;

Parameters

Parameter	Type
_engine	IEngine

Returns

void

Inherited from

System.OnInit

---

OnRender()

OnRender(scene, _renderer): void;

Parameters

Parameter	Type
scene	Scene
_renderer	IRenderer

Returns

void

Overrides

System.OnRender

---

OnRendererChanged()

OnRendererChanged(_renderer): void;

Parameters

Parameter	Type
_renderer	IRenderer

Returns

void

Inherited from

System.OnRendererChanged

---

OnStart()

OnStart(scene, _renderer): void;

Parameters

Parameter	Type
scene	Scene
_renderer	IRenderer

Returns

void

Overrides

System.OnStart

---

OnStop()

OnStop(_scene): void;

Parameters

Parameter	Type
_scene	Scene

Returns

void

Overrides

System.OnStop

---

OnUpdate()

OnUpdate(_scene, _dt): void | Promise<void>;

Parameters

Parameter	Type
_scene	Scene
_dt	number

Returns

void | Promise<void>

Inherited from

System.OnUpdate

---

Refresh()

Refresh(scene): void;

The walk, when something changed. Also run before the update phases (ActiveUpdateSystem), so update systems gating on activeInHierarchy see this tick's state — a freshly loaded scene's inactive entities included.

Parameters

Parameter	Type
scene	Scene

Returns

void