function _flipPng()
{
$source = ImagecreateFromPng($this->_source);
$width = imagesx($source);
$height = imagesy($source);
if ($this->_isPNG8($this->_source)) {
$image = ImageCreate($height, $width);
} else {
$image = ImageCreateTrueColor($height, $width);
imagealphablending($image, false);
imagesavealpha($image, true);
}
if ($this->_hori) {
for ($i = 0; $i < $width; $i++) {
ImageCopyResampled($image, $source, $width - $i - 1, 0, $i, 0, 1, $height, 1, $height);
}
if ($this->_vert) {
ImageCopyResampled($source, $image, 0, 0, 0, 0, $width, $height, $width, $height);
}
}
if ($this->_vert) {
for ($i = 0; $i < $height; $i++) {
ImageCopyResampled($image, $source, 0, $height - $i - 1, 0, $i, $width, 1, $width, 1);
}
}
ImageDestroy($source);
$result = ImagePng($image, $this->_target);
ImageDestroy($image);
return $result;
}
/**
* Internal function for resizing png images.
* @return Bool true or false depending on success or not.
*/
function _resizePng()
{
$source = ImagecreateFromPng($this->_source);
$image = ImageCreate($this->_width, $this->_height);
imagealphablending($image, true);
imagesavealpha($image, true);
$transparent = imagecolorallocatealpha($image, 255, 255, 255, 0);
imagefilledrectangle($image, 0, 0, $this->_width, $this->_height, $transparent);
imagecolortransparent($image, $transparent);
ImageCopyResampled($image, $source, 0, 0, 0, 0, $this->_width, $this->_height, ImageSX($source), ImageSY($source));
$result = ImagePng($image, $this->_target);
ImageDestroy($image);
ImageDestroy($source);
return $result;
}
