Skin.php

<?php
 
/*
 *
 *  ____            _        _   __  __ _                  __  __ ____
 * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
 * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
 * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
 * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * @author PocketMine Team
 * @link http://www.pocketmine.net/
 *
 *
 */
 
declare(strict_types=1);
 
namespace pocketmine\entity;
 
use Ahc\Json\Comment as CommentedJsonDecoder;
use pocketmine\utils\Limits;
use function implode;
use function in_array;
use function json_encode;
use function strlen;
use const JSON_THROW_ON_ERROR;
 
final class Skin{
    public const ACCEPTED_SKIN_SIZES = [
        64 * 32 * 4,
        64 * 64 * 4,
        128 * 128 * 4
    ];
 
    private string $skinId;
    private string $skinData;
    private string $capeData;
    private string $geometryName;
    private string $geometryData;
 
    private static function checkLength(string $string, string $name, int $maxLength) : void{
        if(strlen($string) > $maxLength){
            throw new InvalidSkinException("$name must be at most $maxLength bytes, but have " . strlen($string) . " bytes");
        }
    }
 
    public function __construct(string $skinId, string $skinData, string $capeData = "", string $geometryName = "", string $geometryData = ""){
        self::checkLength($skinId, "Skin ID", Limits::INT16_MAX);
        self::checkLength($geometryName, "Geometry name", Limits::INT16_MAX);
        self::checkLength($geometryData, "Geometry data", Limits::INT32_MAX);
 
        if($skinId === ""){
            throw new InvalidSkinException("Skin ID must not be empty");
        }
        $len = strlen($skinData);
        if(!in_array($len, self::ACCEPTED_SKIN_SIZES, true)){
            throw new InvalidSkinException("Invalid skin data size $len bytes (allowed sizes: " . implode(", ", self::ACCEPTED_SKIN_SIZES) . ")");
        }
        if($capeData !== "" && strlen($capeData) !== 8192){
            throw new InvalidSkinException("Invalid cape data size " . strlen($capeData) . " bytes (must be exactly 8192 bytes)");
        }
 
        if($geometryData !== ""){
            try{
                $decodedGeometry = (new CommentedJsonDecoder())->decode($geometryData);
            }catch(\RuntimeException $e){
                throw new InvalidSkinException("Invalid geometry data: " . $e->getMessage(), 0, $e);
            }
 
            /*
             * Hack to cut down on network overhead due to skins, by un-pretty-printing geometry JSON.
             *
             * Mojang, some stupid reason, send every single model for every single skin in the selected skin-pack.
             * Not only that, they are pretty-printed.
             * TODO: find out what model crap can be safely dropped from the packet (unless it gets fixed first)
             */
            $geometryData = json_encode($decodedGeometry, JSON_THROW_ON_ERROR);
        }
 
        $this->skinId = $skinId;
        $this->skinData = $skinData;
        $this->capeData = $capeData;
        $this->geometryName = $geometryName;
        $this->geometryData = $geometryData;
    }
 
    public function getSkinId() : string{
        return $this->skinId;
    }
 
    public function getSkinData() : string{
        return $this->skinData;
    }
 
    public function getCapeData() : string{
        return $this->capeData;
    }
 
    public function getGeometryName() : string{
        return $this->geometryName;
    }
 
    public function getGeometryData() : string{
        return $this->geometryData;
    }
}