function scaleNearestNeighbor(&$image, &$newImage)
{
$imageInfo = getImageInfo($image);
$colors = array();
for ($y = 0; $y < $imageInfo['height']; $y++) {
for ($x = 0; $x < $imageInfo['width']; $x++) {
$color = imagecolorsforindex($image, imagecolorat($image, $x, $y));
if ($color['alpha'] < 0x7f) {
$hex = ownDecHex($color['red']) . ownDecHex($color['green']) . ownDecHex($color['blue']);
if (!isset($colors[$hex])) {
$colors[$hex] = imagecolorallocatealpha($newImage, $color['red'], $color['green'], $color['blue'], 0x0);
}
imagefilledrectangle($newImage, intval($x * 4), intval($y * 4), intval($x * 4 + 4), intval($y * 4 + 4), $colors[$hex]);
}
}
}
}
*/
require_once './lib.php';
$sprites = glob('./sprites/*.png');
if (!is_dir('./negative')) {
mkdir('./negative');
}
foreach ($sprites as $sprite) {
$image = imagecreatefrompng($sprite);
$imageInfo = getImageInfo($image);
$newImage = imagecreatetruecolor($imageInfo['width'], $imageInfo['height']);
$colors = array();
echo 'Turning sprite ' . basename($sprite, '.png') . ' to negative' . "\n";
imagealphablending($newImage, false);
imagesavealpha($newImage, true);
imagefill($newImage, 0, 0, imagecolorallocatealpha($newImage, 0xff, 0xff, 0xff, 0x7f));
for ($y = 0; $y < $imageInfo['height']; $y++) {
for ($x = 0; $x < $imageInfo['width']; $x++) {
$color = imagecolorsforindex($image, imagecolorat($image, $x, $y));
if ($color['alpha'] < 0x7f) {
$hex = ownDecHex($color['red']) . ownDecHex($color['green']) . ownDecHex($color['blue']);
if (!isset($colors[$hex])) {
$colors[$hex] = imagecolorallocatealpha($newImage, 0xff - $color['red'], 0xff - $color['green'], 0xff - $color['blue'], 0x0);
}
imagesetpixel($newImage, $x, $y, $colors[$hex]);
}
}
}
imagepng($newImage, './negative/' . basename($sprite), 9);
imagedestroy($image);
imagedestroy($newImage);
}