インボリュート曲線

/**
 * Copyright kuma360 ( http://wonderfl.net/user/kuma360 )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/cAxs
 */

package 
{
    import flash.display.Bitmap;
    import flash.display.BitmapData;
    import flash.display.Sprite;
        
    public class Main extends Sprite 
    {
        private var _canvas:BitmapData = new BitmapData ( 465 , 465 , false , 0 ) ;
        
        public function Main():void 
        {
            addChild ( new Bitmap ( _canvas ) ) ;
            
            var a:Number = 5 ;
            var offset:Number = 230 ;
            for ( var I:Number = 0 ; I < 2000 ; ++ I ) {
                var R:Number = I * Math.PI / 180 ;
                var x:Number = a * ( Math.cos ( R ) + R * Math.sin ( R ) ) ;
                var y:Number = a * ( Math.sin ( R ) - R * Math.cos ( R ) ) ;
                _canvas.setPixel ( x + offset , y + offset , 0xFFFFFF ) ;
            }
            
        }
        
    }
    
}