fix(core): Avoid allocating new objects every frame in DepthSensingSystem.

Summary:
Small fixes on the depth occlusion sample to register the component together with the system.

Also, improved the depth sensing system to reuse objects instead of creating new allocations per frame.

Reviewed By: felixtrz

Differential Revision: D94250212

fbshipit-source-id: 591b5ce55eb4ded0923da0484392777a8192738b

Author: zjm-meta

examples/depth-occlusion/src/index.js

@@ -91,7 +91,9 @@ export class OcclusionDemoSystem extends createSystem({
       movementMode: MovementMode.MoveFromTarget,
     });
     entity.addComponent(XRAnchor);
-    entity.addComponent(DepthOccludable, { mode: OcclusionShadersMode.HardOcclusion });
+    entity.addComponent(DepthOccludable, {
+      mode: OcclusionShadersMode.HardOcclusion,
+    });
 
     return entity;
   }
@@ -214,19 +216,18 @@ World.create(document.getElementById('scene-container'), {
   camera.position.set(0, 1.6, 0);
 
   // Register the depth sensing system with occlusion enabled
-  world.registerSystem(DepthSensingSystem, {
-    enableDepthTexture: true,
-    enableOcclusion: true,
-    useFloat32: true,
-    blurRadius: 20.0,
-  });
+  world
+    .registerSystem(DepthSensingSystem, {
+      enableDepthTexture: true,
+      enableOcclusion: true,
+      useFloat32: true,
+      blurRadius: 20.0,
+    })
+    .registerComponent(DepthOccludable);
 
   // Register the demo system
   world.registerSystem(OcclusionDemoSystem);
 
-  // Register the DepthOccludable component
-  world.registerComponent(DepthOccludable);
-
   console.log('Depth Occlusion Demo initialized');
   console.log('Virtual objects will be hidden when behind real-world surfaces');
 });

packages/core/src/depth/depth-sensing-system.ts

@@ -66,6 +66,7 @@ export class DepthSensingSystem extends createSystem(
 
   // Occlusion
   private entityShaderMap = new Map<Entity, Set<ShaderUniforms>>();
+  private readonly viewportSize = new Vector2();
 
   /**
    * Get the raw value to meters conversion factor.
@@ -372,8 +373,7 @@ export class DepthSensingSystem extends createSystem(
     const depthTextureArray = isGPUDepth ? nativeTexture : dataArrayTexture;
     if (!depthTextureArray) return;
 
-    const viewportSize = new Vector2();
-    this.renderer.getDrawingBufferSize(viewportSize);
+    this.renderer.getDrawingBufferSize(this.viewportSize);
 
     for (const [entity, entityUniforms] of this.entityShaderMap) {
       const isHardMode =
@@ -385,7 +385,7 @@ export class DepthSensingSystem extends createSystem(
         uniforms.uRawValueToMeters.value = this.rawValueToMeters;
         uniforms.uIsGPUDepth.value = isGPUDepth;
         uniforms.uDepthNear.value = depthNear;
-        (uniforms.uViewportSize.value as Vector2).copy(viewportSize);
+        (uniforms.uViewportSize.value as Vector2).copy(this.viewportSize);
         uniforms.uOcclusionBlurRadius.value = this.config.blurRadius.value;
         uniforms.uOcclusionHardMode.value = isHardMode;
         uniforms.occlusionEnabled.value = this.config.enableOcclusion.value;