perf(BoundingBox): add isBoundChange tag to Entity (Orillusion#257)

Add tags to entity to check for any changes in the bound, and optimize the repeated calculation of the bound

samples/base/Sample_BoundingBox.ts

@@ -0,0 +1,55 @@
+import { GUIHelp } from '@orillusion/debug/GUIHelp';
+import { Color, Engine3D, Object3D, Object3DUtil, Transform, View3D, } from '@orillusion/core';
+import { GUIUtil } from '@samples/utils/GUIUtil';
+import { createExampleScene, createSceneParam } from '@samples/utils/ExampleScene';
+
+// A sample to show boundingbox
+class Sample_BoundingBox {
+    view: View3D;
+    box: Object3D;
+    container: Object3D;
+    async run() {
+        // init engine
+        await Engine3D.init({ renderLoop: () => { this.loop() } });
+        GUIHelp.init();
+        let param = createSceneParam();
+        param.camera.distance = 1;
+        param.camera.near = 0.01;
+        param.camera.far = 100;
+        param.camera.distance = 2;
+        let exampleScene = createExampleScene(param);
+        Engine3D.startRenderViews([exampleScene.view]);
+        Engine3D.getRenderJob(exampleScene.view);
+
+        let box = Object3DUtil.GetSingleCube(0.5, 0.3, 0.8, 1, 1, 1);
+        box.transform.eventDispatcher.addEventListener(Transform.LOCAL_ONCHANGE, this.logChange, this);
+
+        this.box = box;
+        this.view = exampleScene.view;
+
+        let parent = this.container = new Object3D();
+        parent.addChild(box);
+        exampleScene.scene.addChild(parent);
+
+        GUIHelp.open();
+        GUIHelp.addButton('Remove Box', () => { box.transform.parent && box.removeFromParent(); })
+        GUIHelp.addButton('Add Box', () => { !box.transform.parent && parent.addChild(box); })
+
+        GUIUtil.renderTransform(parent.transform, true, 'Container');
+        GUIUtil.renderTransform(box.transform, true, 'Box');
+
+    }
+
+    logChange() {
+        console.log('BoudingBox changed');
+    }
+
+    red = new Color(1, 0, 0, 1);
+    gree = new Color(0, 1, 0, 1);
+    loop() {
+        this.view.graphic3D.drawBoundingBox(this.box.uuid, this.box.bound as any, this.gree);
+        this.view.graphic3D.drawBoundingBox(this.container.uuid, this.container.bound as any, this.red);
+    }
+}
+
+new Sample_BoundingBox().run()

src/components/ComponentBase.ts

@@ -19,7 +19,15 @@ export class ComponentBase implements IComponent {
     /**
      * @internal
      */
-    public eventDispatcher: CEventDispatcher;
+    protected _eventDispatcher: CEventDispatcher;
+    public get eventDispatcher() {
+        this._eventDispatcher ||= new CEventDispatcher();
+        return this._eventDispatcher;
+    }
+
+    public set eventDispatcher(value) {
+        console.error('The eventDispatcher should not be set externally!');
+    }
 
     /**
      * @internal
@@ -28,9 +36,6 @@ export class ComponentBase implements IComponent {
 
     private __isStart: boolean = false;
 
-    constructor() {
-        this.eventDispatcher = new CEventDispatcher();
-    }
 
     /**
      * Return the Transform component attached to the Object3D.