There seem to be craploads of problems to do with resizing and rotating them, but I haven't come across anythong like my current problem: The alpha is off by one pixel, in the x axis only.
Here's the code:
$sizes = getimagesize($_FILES['uploadedfile']['tmp_name']);
$imtc = imagecreatetruecolor($sizes, $sizes);
$transparent = imagecolorallocate($imtc, 255, 0, 255);
imagefilledrectangle($imtc, 0, 0, $sizes, $sizes, $transparent);
imagecopy($imtc, $im, 0, 0, 0, 0, $sizes, $sizes);
imagecolortransparent($imtc, $transparent); //files output here are not transparent at all
imagetruecolortopalette($imtc, false, 32);
imagegif($imtc, 'result.gif'); //this file's alpha is correct other than being x+1.
And the images (fake pokemon sprites, haha):
This seems to be a byproduct of the imagetruecolortopalette function as noted above.
Could I alter the pixel data itself? Would it matter? Thanks a lot for any help!