Incorporate some changes from Billboards in #2669.

CesiumGS · Apr 29, 2015 · 31c7920 · 31c7920
1 parent 62a4593
commit 31c7920
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Showing 3 changed files with 17 additions and 5 deletions.
diff --git a/Source/Scene/PointPrimitive.js b/Source/Scene/PointPrimitive.js
@@ -391,7 +391,7 @@ define([
     var scratchMatrix4 = new Matrix4();
     var scratchCartesian4 = new Cartesian4();
 
-    PointPrimitive._computeScreenSpacePosition = function(modelMatrix, position, scene) {
+    PointPrimitive._computeScreenSpacePosition = function(modelMatrix, position, scene, result) {
         // This function is basically a stripped-down JavaScript version of PointPrimitiveCollectionVS.glsl
         var camera = scene.camera;
         var view = camera.viewMatrix;
@@ -401,7 +401,7 @@ define([
         var mv = Matrix4.multiplyTransformation(view, modelMatrix, scratchMatrix4);
         var positionEC = Matrix4.multiplyByVector(mv, Cartesian4.fromElements(position.x, position.y, position.z, 1, scratchCartesian4), scratchCartesian4);
         var positionCC = Matrix4.multiplyByVector(projection, positionEC, scratchCartesian4); // clip coordinates
-        var positionWC = SceneTransforms.clipToGLWindowCoordinates(scene, positionCC, new Cartesian2());
+        var positionWC = SceneTransforms.clipToGLWindowCoordinates(scene, positionCC, result);
 
         return positionWC;
     };
@@ -412,15 +412,19 @@ define([
      * left to right, and <code>y</code> increases from top to bottom.
      *
      * @param {Scene} scene The scene.
+     * @param {Cartesian2} [result] The object onto which to store the result.
      * @returns {Cartesian2} The screen-space position of the point.
      *
      * @exception {DeveloperError} PointPrimitive must be in a collection.
      *
      * @example
      * console.log(p.computeScreenSpacePosition(scene).toString());
      */
-    PointPrimitive.prototype.computeScreenSpacePosition = function(scene) {
+    PointPrimitive.prototype.computeScreenSpacePosition = function(scene, result) {
         var pointPrimitiveCollection = this._pointPrimitiveCollection;
+        if (!defined(result)) {
+            result = new Cartesian2();
+        }
 
         //>>includeStart('debug', pragmas.debug);
         if (!defined(pointPrimitiveCollection)) {
@@ -432,7 +436,7 @@ define([
         //>>includeEnd('debug');
 
         var modelMatrix = pointPrimitiveCollection.modelMatrix;
-        var windowCoordinates = PointPrimitive._computeScreenSpacePosition(modelMatrix, this._actualPosition, scene);
+        var windowCoordinates = PointPrimitive._computeScreenSpacePosition(modelMatrix, this._actualPosition, scene, result);
         windowCoordinates.y = scene.canvas.clientHeight - windowCoordinates.y;
         return windowCoordinates;
     };

diff --git a/Source/Scene/PointPrimitiveCollection.js b/Source/Scene/PointPrimitiveCollection.js
@@ -671,7 +671,7 @@ define([
         boundingVolume.radius += size;
     }
 
-    var writers = [];
+    var scratchWriterArray = [];
 
     /**
      * @private
@@ -725,6 +725,7 @@ define([
         } else {
             // PointPrimitives were modified, but none were added or removed.
             if (pointPrimitivesToUpdateLength > 0) {
+                var writers = scratchWriterArray;
                 writers.length = 0;
 
                 if (properties[POSITION_INDEX] || properties[OUTLINE_WIDTH_INDEX] || properties[PIXEL_SIZE_INDEX]) {

diff --git a/Specs/Scene/PointPrimitiveCollectionSpec.js b/Specs/Scene/PointPrimitiveCollectionSpec.js
@@ -365,6 +365,10 @@ defineSuite([
         expect(pointPrimitives.contains(new Cartesian2())).toEqual(false);
     });
 
+    it('does not render when constructed', function() {
+        expect(scene.renderForSpecs()).toEqual([0, 0, 0, 255]);
+    });
+
     it('modifies and removes a pointPrimitive, then renders', function() {
         var p1 = pointPrimitives.add({
             position : Cartesian3.ZERO,
@@ -659,6 +663,7 @@ defineSuite([
             }
         });
 
+        // This tests the `PointPrimitiveCollection.equals` function itself, not simple equality.
         expect(p.equals(p2)).toEqual(true);
     });
 
@@ -670,10 +675,12 @@ defineSuite([
             position : new Cartesian3(4.0, 5.0, 6.0)
         });
 
+        // This tests the `PointPrimitiveCollection.equals` function itself, not simple equality.
         expect(p.equals(p2)).toEqual(false);
     });
 
     it('does not equal undefined', function() {
+        // This tests the `PointPrimitiveCollection.equals` function itself, not simple equality.
         var pointPrimitive = pointPrimitives.add();
         expect(pointPrimitive.equals(undefined)).toEqual(false);
     });