Определение цвета в прозрачной BitmapData

Код AS3:

var zz:uint = 0x90CCCCCC;
var del:Number = (zz >>> 24) / 0xFF;
zz *= del;
zz /= del;
trace("0xZZ=0x" + (zz >>> 24).toString(16) + (zz & 0xFFFFFF).toString(16));
//0xZZ=0x90ccccca

R = 0xFF & (k * R);
G = 0xFF & (k * G);
B = 0xFF & (k * B);
color = (R << 16) | (G << 8) | B;

resultColor = color | backgroundColor;

trace((0x90 / 0xFF).toFixed(8)); //0.56470588 
trace((0.56470588 * 0xFF).toString(16)); //8f

function setPixel32(color) {
  A = (color >>> 24);
  R = (color >>> 16) & 0xFF;
  G = (color >>> 8) & 0xFF;
  B = color & 0xFF;
  newA = A;
  newR = Math.round(A*R/255);
  newG = Math.round(A*G/255);
  newB = Math.round(A*B/255);
  color = (newA << 24) | (newR << 16) | (newG << 8) | newB;
}

function getPixel32() {
  A = (color >>> 24);
  R = (color >>> 16) & 0xFF;
  G = (color >>> 8) & 0xFF;
  B = color & 0xFF;
  oldA = A;
  oldR = R*255/A;
  oldG = G*255/A;
  oldB = B*255/A;
  color = (oldA << 24) | (oldR << 16) | (oldG << 8) | oldB;
  return color;
}

focus=0x90CCCCCC
toHex(focus) // 0x90cccccc

focus=setPixel32(focus)
toHex(focus) // 0xd6666666

focus=getPixel32(focus)
toHex(focus) // 0x00



function setPixel32(color) {
  A = (color << 24);
  R = (color << 16) & 0xFF;
  G = (color << 8) & 0xFF;
  B = color & 0xFF;
  newA = A;
  newR = Math.round(A*R/255);
  newG = Math.round(A*G/255);
  newB = Math.round(A*B/255);
  color = (newA << 24) | (newR << 16) | (newG << 8) | newB;
  return color
}

function getPixel32(color) {
  A = (color << 24);
  R = (color << 16) & 0xFF;
  G = (color << 8) & 0xFF;
  B = color & 0xFF;
  oldA = A;
  oldR = R*255/A;
  oldG = G*255/A;
  oldB = B*255/A;
  color = (oldA << 24) | (oldR << 16) | (oldG << 8) | oldB;
  return color;
}

function toHex(num){
	trace("0x"+(num>>>24).toString(16)+(num & 0xFFFFFF).toString(16))
}