RuntimeDataWriter.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\data\runtime;
 
use pocketmine\block\utils\WallConnectionType;
use pocketmine\math\Axis;
use pocketmine\math\Facing;
use function log;
use function spl_object_id;
 
final class RuntimeDataWriter implements RuntimeDataDescriber{
    private int $value = 0;
    private int $offset = 0;
 
    public function __construct(
        private int $maxBits
    ){}
 
    public function writeInt(int $bits, int $value) : void{
        if($this->offset + $bits > $this->maxBits){
            throw new \InvalidArgumentException("Bit buffer cannot be larger than $this->maxBits bits (already have $this->offset bits)");
        }
        if(($value & (~0 << $bits)) !== 0){
            throw new \InvalidArgumentException("Value $value does not fit into $bits bits");
        }
 
        $this->value |= ($value << $this->offset);
        $this->offset += $bits;
    }
 
    public function int(int $bits, int &$value) : void{
        $this->writeInt($bits, $value);
    }
 
    private function writeBoundedIntAuto(int $min, int $max, int $value) : void{
        if($value < $min || $value > $max){
            throw new \InvalidArgumentException("Value $value is outside the range $min - $max");
        }
        $bits = ((int) log($max - $min, 2)) + 1;
        $this->writeInt($bits, $value - $min);
    }
 
    public function boundedIntAuto(int $min, int $max, int &$value) : void{
        $this->writeBoundedIntAuto($min, $max, $value);
    }
 
    protected function writeBool(bool $value) : void{
        $this->writeInt(1, $value ? 1 : 0);
    }
 
    public function bool(bool &$value) : void{
        $this->writeBool($value);
    }
 
    public function facingExcept(Facing &$facing, Facing $except) : void{
        $this->enum($facing);
    }
 
    public function horizontalAxis(Axis &$axis) : void{
        $this->writeInt(1, match($axis){
            Axis::X => 0,
            Axis::Z => 1,
            default => throw new \InvalidArgumentException("Invalid horizontal axis $axis->name")
        });
    }
 
    public function wallConnections(array &$connections) : void{
        $packed = 0;
        $offset = 0;
        foreach(Facing::HORIZONTAL as $facing){
            $packed += match($connections[$facing->value] ?? null){
                null => 0,
                WallConnectionType::SHORT => 1,
                WallConnectionType::TALL => 2,
            } * (3 ** $offset);
            $offset++;
        }
        $this->writeBoundedIntAuto(0, (3 ** 4) - 1, $packed);
    }
 
    public function enum(\UnitEnum &$case) : void{
        $metadata = RuntimeEnumMetadata::from($case);
        $this->writeInt($metadata->bits, $metadata->enumToInt($case));
    }
 
    public function enumSet(array &$set, array $allCases) : void{
        foreach($allCases as $case){
            $this->writeBool(isset($set[spl_object_id($case)]));
        }
    }
 
    public function getValue() : int{ return $this->value; }
 
    public function getOffset() : int{ return $this->offset; }
}