refactor: avoid adding new helper function

Author: donmccurdy

packages/engine/Source/Renderer/TextureAtlas.js

@@ -193,17 +193,22 @@ Object.defineProperties(TextureAtlas.prototype, {
 });
 
 /**
- * Get integer pixel coordinates for a given image or image region.
+ * Get the texture coordinates for reading the associated image in shaders.
  * @param {number} index The index of the image region.
  * @param {BoundingRectangle} [result] The object into which to store the result.
  * @return {BoundingRectangle} The modified result parameter or a new BoundingRectangle instance if one was not provided.
  * @private
+ * @example
+ * const index = await atlas.addImage("myImage", image);
+ * const rectangle = atlas.computeTextureCoordinates(index);
+ * BoundingRectangle.pack(rectangle, bufferView);
  */
-TextureAtlas.prototype.computePixelCoordinates = function (index, result) {
+TextureAtlas.prototype.computeTextureCoordinates = function (index, result) {
   //>>includeStart('debug', pragmas.debug);
   Check.typeOf.number.greaterThanOrEquals("index", index, 0);
   //>>includeEnd('debug');
 
+  const texture = this._texture;
   const rectangle = this._rectangles[index];
 
   if (!defined(result)) {
@@ -219,6 +224,9 @@ TextureAtlas.prototype.computePixelCoordinates = function (index, result) {
     return result;
   }
 
+  const atlasWidth = texture.width;
+  const atlasHeight = texture.height;
+
   const width = rectangle.width;
   const height = rectangle.height;
   let x = rectangle.x;
@@ -232,36 +240,10 @@ TextureAtlas.prototype.computePixelCoordinates = function (index, result) {
     y += parentRectangle.y;
   }
 
-  result.x = x;
-  result.y = y;
-  result.width = width;
-  result.height = height;
-
-  return result;
-};
-
-/**
- * Get the texture coordinates for reading the associated image in shaders.
- * @param {number} index The index of the image region.
- * @param {BoundingRectangle} [result] The object into which to store the result.
- * @return {BoundingRectangle} The modified result parameter or a new BoundingRectangle instance if one was not provided.
- * @private
- * @example
- * const index = await atlas.addImage("myImage", image);
- * const rectangle = atlas.computeTextureCoordinates(index);
- * BoundingRectangle.pack(rectangle, bufferView);
- */
-TextureAtlas.prototype.computeTextureCoordinates = function (index, result) {
-  result = this.computePixelCoordinates(index, result);
-
-  const texture = this._texture;
-  const atlasWidth = texture.width;
-  const atlasHeight = texture.height;
-
-  result.x /= atlasWidth;
-  result.y /= atlasHeight;
-  result.width /= atlasWidth;
-  result.height /= atlasHeight;
+  result.x = x / atlasWidth;
+  result.y = y / atlasHeight;
+  result.width = width / atlasWidth;
+  result.height = height / atlasHeight;
 
   return result;
 };

packages/engine/Specs/Renderer/TextureAtlasSpec.js

@@ -1398,7 +1398,13 @@ function drawAtlas(atlas, indices) {
 
   // draw each rectangle, filling with its index.
   for (const index of indices) {
-    atlas.computePixelCoordinates(index, rect);
+    // compute rectangle coordinates in pixels.
+    atlas.computeTextureCoordinates(index, rect);
+    rect.x *= width;
+    rect.y *= height;
+    rect.width *= width;
+    rect.height *= height;
+
     for (let dx = 0; dx < rect.width; dx++) {
       const x = rect.x + dx;
       for (let dy = 0; dy < rect.height; dy++) {