Crop MovieClip to Bitmap (AS3)

function crop( _x:Number, _y:Number, _width:Number, _height:Number, displayObject:DisplayObject = null):Bitmap { var cropArea:Rectangle = new Rectangle( 0, 0, _width, _height ); var croppedBitmap:Bitmap = new Bitmap( new BitmapData( _width, _height ), PixelSnapping.ALWAYS, true ); croppedBitmap.bitmapData.draw( (displayObject!=null) ? displayObject : stage, new Matrix(1, 0, 0, 1, -_x, -_y) , null, null, cropArea, true ); return croppedBitmap; } var myCroppedImage:Bitmap = crop( 100, 100, 200, 200 ); this.addChild ( myCroppedImage );