Testing pivotPoint argument of prependRotation() method

/**
 * Copyright Fumio ( http://wonderfl.net/user/Fumio )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/tOTV
 */

package {
	import flash.display.Sprite;
	import flash.display.Graphics;
	import flash.geom.Matrix3D;
	import flash.geom.Vector3D;
	import flash.events.Event;
	public class prependRotationPivotPointTest extends Sprite {
		private var mySprite:Sprite;
		private var nX:Number = stage.stageWidth / 2;
		private var nY:Number = stage.stageHeight / 2;
		private var nRotationY:Number = 5;
		private var myMatrix3D:Matrix3D = new Matrix3D();
		private var pivotVector3D:Vector3D = new Vector3D(nX,nY,0);
		public function prependRotationPivotPointTest() {
			mySprite = createRectangle();
			mySprite.transform.matrix3D = myMatrix3D;
			myMatrix3D.appendTranslation(nX, nY, 0);
			addChild(mySprite);
			addEventListener(Event.ENTER_FRAME, xRotate);
		}
		private function createRectangle():Sprite {
			var _sprite:Sprite = new Sprite();
			var myGraphics:Graphics = _sprite.graphics;
			myGraphics.beginFill(0x0000FF);
			myGraphics.drawRect(-50, -50, 100, 100);
			myGraphics.endFill();
			return _sprite;
		}
		private function xRotate(eventObject:Event):void {
			myMatrix3D.appendTranslation(-nX, -nY, 0);
			// myMatrix3D.appendRotation(nRotationY, Vector3D.Y_AXIS);
			// myMatrix3D.appendTranslation(nX, nY, 0);
			// The two statements above are equivalent to the next statement.
			myMatrix3D.appendRotation(nRotationY, Vector3D.Y_AXIS, pivotVector3D);
		}
	}
}