Add existing to tracked

node_modules/@cesium/engine/Source/Renderer/TextureCache.js

@@ -0,0 +1,81 @@
+import defined from "../Core/defined.js";
+import destroyObject from "../Core/destroyObject.js";
+
+/**
+ * @private
+ */
+function TextureCache() {
+  this._textures = {};
+  this._numberOfTextures = 0;
+  this._texturesToRelease = {};
+}
+
+Object.defineProperties(TextureCache.prototype, {
+  numberOfTextures: {
+    get: function () {
+      return this._numberOfTextures;
+    },
+  },
+});
+
+TextureCache.prototype.getTexture = function (keyword) {
+  const cachedTexture = this._textures[keyword];
+  if (!defined(cachedTexture)) {
+    return undefined;
+  }
+
+  // No longer want to release this if it was previously released.
+  delete this._texturesToRelease[keyword];
+
+  ++cachedTexture.count;
+  return cachedTexture.texture;
+};
+
+TextureCache.prototype.addTexture = function (keyword, texture) {
+  const cachedTexture = {
+    texture: texture,
+    count: 1,
+  };
+
+  texture.finalDestroy = texture.destroy;
+
+  const that = this;
+  texture.destroy = function () {
+    if (--cachedTexture.count === 0) {
+      that._texturesToRelease[keyword] = cachedTexture;
+    }
+  };
+
+  this._textures[keyword] = cachedTexture;
+  ++this._numberOfTextures;
+};
+
+TextureCache.prototype.destroyReleasedTextures = function () {
+  const texturesToRelease = this._texturesToRelease;
+
+  for (const keyword in texturesToRelease) {
+    if (texturesToRelease.hasOwnProperty(keyword)) {
+      const cachedTexture = texturesToRelease[keyword];
+      delete this._textures[keyword];
+      cachedTexture.texture.finalDestroy();
+      --this._numberOfTextures;
+    }
+  }
+
+  this._texturesToRelease = {};
+};
+
+TextureCache.prototype.isDestroyed = function () {
+  return false;
+};
+
+TextureCache.prototype.destroy = function () {
+  const textures = this._textures;
+  for (const keyword in textures) {
+    if (textures.hasOwnProperty(keyword)) {
+      textures[keyword].texture.finalDestroy();
+    }
+  }
+  return destroyObject(this);
+};
+export default TextureCache;