flash on 2010-4-13

/**
 * Copyright kihon ( http://wonderfl.net/user/kihon )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/vkH1
 */

package
{
	import flash.display.Sprite;
 
	public class Main extends Sprite
	{	
		public function Main()
		{
			graphics.beginFill(alphaBlend(0xFF0000, 0xFFFFFF, 0.2));
			graphics.drawRect(0, 0, 100, 100);
			graphics.endFill();
		}
 
		private function alphaBlend(front:int, back:int, alpha:Number):int
		{
			var r:int = ((front >> 16 & 0xFF) * alpha + (back >> 16 & 0xFF) * (1 - alpha));
			var g:int = ((front >> 8  & 0xFF) * alpha + (back >>  8 & 0xFF) * (1 - alpha));
			var b:int = ((front       & 0xFF) * alpha + (back       & 0xFF) * (1 - alpha));
 
			return (r << 16) + (g << 8) + b;
		}
	}
}