generate orientation texture

TextureGenerator.as

public static function generateOrientationTexture(size:int):BitmapData {
	var half:uint = size / 2;
	var bmd:BitmapData = new BitmapData(size, size, false, 0x000000);
	for (var i:uint = 0; i < size; i++) {
		for (var j:uint = 0; j < size; j++) {
			var directionX:Number = i - half;
			var directionY:Number = j - half;
			var length:Number = Math.sqrt(directionX * directionX + directionY * directionY);
			directionX /= length;
			directionY /= length;

			var red:uint = packFloat(directionX);
			var green:uint = packFloat(directionY);
			bmd.setPixel(i, j, (red << 16) + (green << 8) + 0xFF);
		}
	}
	return bmd;
}

private static function packFloat(value:Number):uint {
	var result:uint;
	if (value < 0) {
		result = 128 - Math.abs(value) * 128;
	} else {
		result = value * 128 + 128;
	}
	if (result > 255) result = 255;
	return result;
}