/**
* Applies a mask on the copy of source image
*
* @param GDImage_Image $image
* @param GDImage_Image $mask
* @param smart_coordinate $left
* @param smart_coordinate $top
* @return GDImage_Image
*/
function execute($image, $mask, $left = 0, $top = 0)
{
$left = WideImage_Coordinate::fix($left, $image->getWidth(), $mask->getWidth());
$top = WideImage_Coordinate::fix($top, $image->getHeight(), $mask->getHeight());
$width = $image->getWidth();
$mask_width = $mask->getWidth();
$height = $image->getHeight();
$mask_height = $mask->getHeight();
$result = $image->asTrueColor();
$result->alphaBlending(false);
$result->saveAlpha(true);
$srcTransparentColor = $result->getTransparentColor();
if ($srcTransparentColor >= 0) {
$destTransparentColor = $srcTransparentColor;
} else {
$destTransparentColor = $result->allocateColorAlpha(255, 255, 255, 127);
}
for ($x = 0; $x < $width; $x++) {
for ($y = 0; $y < $height; $y++) {
$mx = $x - $left;
$my = $y - $top;
if ($mx >= 0 && $mx < $mask_width && $my >= 0 && $my < $mask_height) {
$srcColor = $image->getColorAt($x, $y);
if ($srcColor == $srcTransparentColor) {
$destColor = $destTransparentColor;
} else {
$maskRGB = $mask->getRGBAt($mx, $my);
if ($maskRGB['red'] == 0) {
$destColor = $destTransparentColor;
} elseif ($srcColor >= 0) {
$imageRGB = $image->getRGBAt($x, $y);
$level = $maskRGB['red'] / 255 * (1 - $imageRGB['alpha'] / 127);
$imageRGB['alpha'] = 127 - round($level * 127);
if ($imageRGB['alpha'] == 127) {
$destColor = $destTransparentColor;
} else {
$destColor = $result->allocateColorAlpha($imageRGB);
}
} else {
$destColor = $destTransparentColor;
}
}
$result->setColorAt($x, $y, $destColor);
}
}
}
return $result;
}
