More cleanup?

assets/entities/cube.js

@@ -2,12 +2,9 @@ function CubeEntity() {
   Entity.call(this);
 
   this.add(POSITION);
+  this.position.position = new Vec3(1, 0, 0);
   this.add(MESH);
   this.add(MATERIAL);
-  
-  this.position.x = 0;
-  this.position.y = 0;
-  this.position.z = 0;
 }
 
 CubeEntity.prototype = Object.create(Entity.prototype);
@@ -16,9 +13,13 @@ CubeEntity.prototype.constructor = CubeEntity;
 CubeEntity.prototype.update = function() {
   var speed = 3.0;
   var move = Input.axis2D(INPUT_ACTION_LEFT, INPUT_ACTION_RIGHT, INPUT_ACTION_UP, INPUT_ACTION_DOWN);
-  this.position.x += move.x * speed * TIME.delta;
-  this.position.z += move.y * speed * TIME.delta;
+  var pos = this.position.position;
+  this.position.position = new Vec3(
+    pos.x + move.x * speed * TIME.delta,
+    pos.y,
+    pos.z + move.y * speed * TIME.delta
+  );
   this.material.setColor(Color.rainbow());
 };
 
-module = CubeEntity;
+module = CubeEntity;