skin.php

<?php
class Skin{
	public static function getTextureFromFile(string $filename) : string{
		$im = imagecreatefrompng($filename);
		list($width, $height) = getimagesize($filename);
		$bytes = "";
		for($y = 0; $y < $height; $y++){
			for($x = 0; $x < $width; $x++){
				$code = imagecolorat($im, $x, $y);
				$bytes .= chr(($code >> 16) & 0xff) . chr(($code >> 8) & 0xff) . chr(($code >> 16) & 0xff) . ($code >> 24) & 0xff;
			}
		}
		imagedestroy($im);
		return $bytes;
	}

	public static function saveTextureToFile(string $filename, string $bytes) : void{
		$len = strlen($bytes);
		$im = imagecreatetruecolor(64, $len === 8192 ? 32 : 64);
		$x = $y = $part = 0;
		while($y < 64){
			$cid = substr($bytes, $part, 3);
			if(isset($cid[0])){
				imagesetpixel($im, $x, $y, imagecolorallocate($im, ord($cid[0]), ord($cid[1]), ord($cid[2])));
			}
			$x++;
			$part += 4;
			if($x === 64){
				$x = 0;
				$y++;
			}
		}
		imagepng($im, $filename);
		imagedestroy($im);
	}
}