RefCountedObject base class, used on Mesh and Morph (playcanvas#2650)

mvaligursky · willeastcott · web-flow · commit 0f403ee07291 · 2020-12-30T21:26:22.000Z
* RefCount base class, used on Mesh and Morph

* Remove newline

* == to ===

* fix to tests

- fixes setting mesh to the same (would destroy mesh first, then assign destroyed copy)�
- fixed mesh destroy by sprite

* loop

* renamed RefCount -&gt; RefCountedObject

Co-authored-by: Will Eastcott &lt;will@playcanvas.com&gt;
diff --git a/src/core/ref-counted-object.js b/src/core/ref-counted-object.js
@@ -0,0 +1,33 @@
+// base class for reference counted objects
+class RefCountedObject {
+    constructor() {
+        // counter
+        this._refCount = 0;
+    }
+
+    // inrements the counter
+    incRefCount() {
+        this._refCount++;
+    }
+
+    // decrements the counter. When the value reaches zero, destroy is called
+    decRefCount() {
+        if (--this._refCount === 0) {
+            this.destroy();
+        }
+    }
+
+    // returns current count
+    getRefCount() {
+        return this._refCount;
+    }
+
+    // default version of destroy functionality
+    destroy() {
+        // #ifdef DEBUG
+        console.error("Class extended from the RefCountedObject class needs to have a destroy function implemented.");
+        // #endif
+    }
+}
+
+export { RefCountedObject };
diff --git a/src/index.js b/src/index.js
@@ -22,6 +22,7 @@ export { IndexedList } from './core/indexed-list.js';
 export { Tags } from './core/tags.js';
 export { Timer, now } from './core/time.js';
 export { URI, createURI } from './core/uri.js';
+export { RefCountedObject } from './core/ref-counted-object.js';
 
 // NET
 export { http, Http } from './net/http.js';
diff --git a/src/scene/mesh-instance.js b/src/scene/mesh-instance.js
@@ -97,8 +97,8 @@ class MeshInstance {
         this._staticSource = null;
 
         this.node = node;           // The node that defines the transform of the mesh instance
-        this._mesh = mesh;           // The mesh that this instance renders
-        mesh.incReference();
+        this._mesh = mesh;          // The mesh that this instance renders
+        mesh.incRefCount();
         this.material = material;   // The material with which to render this instance
 
         this._shaderDefs = MASK_DYNAMIC << 16; // 2 byte toggles, 2 bytes light mask; Default value is no toggles and mask = pc.MASK_DYNAMIC
@@ -156,14 +156,19 @@ class MeshInstance {
     }
 
     set mesh(mesh) {
+
+        if (mesh === this._mesh)
+            return;
+
         if (this._mesh) {
-            this._mesh.decReference();
+            // this destroys the mesh if refcount gets to 0
+            this._mesh.decRefCount();
         }
 
         this._mesh = mesh;
 
         if (mesh) {
-            mesh.incReference();
+            mesh.incRefCount();
         }
     }
 
@@ -392,15 +397,15 @@ class MeshInstance {
 
     destroy() {
 
-        var mesh = this.mesh;
-        if (mesh) {
-            this.mesh = null;   // this calls decReference on mesh
-            if (mesh.refCount < 1) {
-                mesh.destroy();
-            }
+        if (this.mesh) {
+            // release previous mesh
+            this.mesh = null;
         }
 
-        this.destroySkinInstance();
+        if (this._skinInstance) {
+            this._skinInstance.destroy();
+            this._skinInstance = null;
+        }
 
         if (this.morphInstance) {
             this.morphInstance.destroy();
@@ -411,13 +416,6 @@ class MeshInstance {
         this.material = null;
     }
 
-    destroySkinInstance() {
-        if (this._skinInstance) {
-            this._skinInstance.destroy();
-            this._skinInstance = null;
-        }
-    }
-
     syncAabb() {
         // Deprecated
     }
diff --git a/src/scene/mesh.js b/src/scene/mesh.js
@@ -1,3 +1,4 @@
+import { RefCountedObject } from '../core/ref-counted-object.js';
 import { Vec3 } from '../math/vec3.js';
 
 import { BoundingBox } from '../shape/bounding-box.js';
@@ -175,9 +176,9 @@ class GeometryVertexStream {
  * @property {pc.Skin} [skin] The skin data (if any) that drives skinned mesh animations for this mesh.
  * @property {pc.Morph} [morph] The morph data (if any) that drives morph target animations for this mesh.
  */
-class Mesh {
+class Mesh extends RefCountedObject {
     constructor(graphicsDevice) {
-        this._refCount = 0;
+        super();
         this.id = id++;
         this.device = graphicsDevice || Application.getApplication().graphicsDevice;
         this.vertexBuffer = null;
@@ -206,18 +207,6 @@ class Mesh {
         this._aabb = aabb;
     }
 
-    get refCount() {
-        return this._refCount;
-    }
-
-    incReference() {
-        this._refCount++;
-    }
-
-    decReference() {
-        this._refCount--;
-    }
-
     /**
      * @function
      * @name pc.Mesh#destroy
diff --git a/src/scene/morph-instance.js b/src/scene/morph-instance.js
@@ -23,6 +23,7 @@ var textureMorphVertexShader =
 class MorphInstance {
     constructor(morph) {
         this.morph = morph;
+        morph.incRefCount();
         this.device = morph.device;
         this.meshInstance = null;
 
@@ -108,7 +109,8 @@ class MorphInstance {
         this.shader = null;
 
         if (this.morph) {
-            this.morph.destroy();
+            // this destroys morph if refcount gets to 0
+            this.morph.decRefCount();
             this.morph = null;
         }
 
diff --git a/src/scene/morph.js b/src/scene/morph.js
@@ -1,3 +1,4 @@
+import { RefCountedObject } from '../core/ref-counted-object.js';
 import { Vec3 } from '../math/vec3.js';
 import { math } from '../math/math.js';
 import { BoundingBox } from '../shape/bounding-box.js';
@@ -16,8 +17,9 @@ import { BUFFER_STATIC, TYPE_FLOAT32, SEMANTIC_ATTR15, ADDRESS_CLAMP_TO_EDGE, FI
  * @param {pc.GraphicsDevice} graphicsDevice - The graphics device used to manage this morph target. If it is not provided, a device is obtained
  * from the {@link pc.Application}.
  */
-class Morph {
+class Morph extends RefCountedObject {
     constructor(targets, graphicsDevice) {
+        super();
 
         this.device = graphicsDevice || Application.getApplication().graphicsDevice;
         this._targets = targets;
diff --git a/src/scene/sprite.js b/src/scene/sprite.js
@@ -252,18 +252,10 @@ Sprite.prototype.endUpdate = function () {
  * @description Free up the meshes created by the sprite.
  */
 Sprite.prototype.destroy = function () {
-    var i;
-    var len;
 
-    // destroy old meshes
-    for (i = 0, len = this._meshes.length; i < len; i++) {
-        var mesh = this._meshes[i];
-        if (!mesh) continue;
-
-        mesh.vertexBuffer.destroy();
-        for (var j = 0, len2 = mesh.indexBuffer.length; j < len2; j++) {
-            mesh.indexBuffer[j].destroy();
-        }
+    for (const mesh of this._meshes) {
+        if (mesh)
+            mesh.destroy();
     }
     this._meshes.length = 0;
 };
