Rectangle.Union will now cache all vars internally so you can use one of the input rectangles as the output rectangle without corrupting it.

Author: photonstorm

CHANGELOG.md

@@ -106,6 +106,7 @@
 * List.sort no longer takes an array as its argument, instead it only sorts the List contents by the defined property.
 * List.addMultiple has been removed. Used `List.add` instead which offers the exact same functionality.
 * List is now internally using all of the new Utils.Array functions.
+* Rectangle.Union will now cache all vars internally so you can use one of the input rectangles as the output rectangle without corrupting it.
 
 ### Animation System Updates
 

src/geom/rectangle/Union.js

@@ -24,15 +24,13 @@ var Union = function (rectA, rectB, out)
 {
     if (out === undefined) { out = new Rectangle(); }
 
+    //  Cache vars so we can use one of the input rects as the output rect
     var x = Math.min(rectA.x, rectB.x);
     var y = Math.min(rectA.y, rectB.y);
+    var w = Math.max(rectA.right, rectB.right) - x;
+    var h = Math.max(rectA.bottom, rectB.bottom) - y;
 
-    return out.setTo(
-        x,
-        y,
-        Math.max(rectA.right, rectB.right) - x,
-        Math.max(rectA.bottom, rectB.bottom) - y
-    );
+    return out.setTo(x, y,w, h);
 };
 
 module.exports = Union;