Matrixで回転

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

package {
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.geom.Matrix;
    
    public class FlashTest extends Sprite {
        private var angle:Number = 0;
        private var box:Sprite;
        
        public function FlashTest() {
            init();         
        }
        
        private function init():void {
            box = new Sprite();
            box.graphics.beginFill( 0xff0000 );
            box.graphics.drawRect( -50, -50, 100, 100 );
            box.graphics.endFill();
            addChild( box );
            
            addEventListener(Event.ENTER_FRAME, onEnterFrame);
        }
        
        private function onEnterFrame(e:Event):void {
            angle += 0.1;
            var cos:Number = Math.cos( angle );
            var sin:Number = Math.sin( angle );
            box.transform.matrix = new Matrix( cos, sin, -sin, cos, stage.stageWidth / 2, stage.stageHeight / 2);
        }

    }
}