SubChunkExplorer.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\world\utils;
 
use pocketmine\world\ChunkManager;
use pocketmine\world\format\Chunk;
use pocketmine\world\format\SubChunk;
 
class SubChunkExplorer{
    public ?Chunk $currentChunk = null;
    public ?SubChunk $currentSubChunk = null;
 
    protected int $currentX;
    protected int $currentY;
    protected int $currentZ;
 
    public function __construct(
        protected ChunkManager $world
    ){}
 
    public function moveTo(int $x, int $y, int $z) : int{
        $newChunkX = $x >> SubChunk::COORD_BIT_SIZE;
        $newChunkZ = $z >> SubChunk::COORD_BIT_SIZE;
        if($this->currentChunk === null || $this->currentX !== $newChunkX || $this->currentZ !== $newChunkZ){
            $this->currentX = $newChunkX;
            $this->currentZ = $newChunkZ;
            $this->currentSubChunk = null;
 
            $this->currentChunk = $this->world->getChunk($this->currentX, $this->currentZ);
            if($this->currentChunk === null){
                return SubChunkExplorerStatus::INVALID;
            }
        }
 
        $newChunkY = $y >> SubChunk::COORD_BIT_SIZE;
        if($this->currentSubChunk === null || $this->currentY !== $newChunkY){
            $this->currentY = $newChunkY;
 
            if($this->currentY < Chunk::MIN_SUBCHUNK_INDEX || $this->currentY > Chunk::MAX_SUBCHUNK_INDEX){
                $this->currentSubChunk = null;
                return SubChunkExplorerStatus::INVALID;
            }
 
            $this->currentSubChunk = $this->currentChunk->getSubChunk($newChunkY);
            return SubChunkExplorerStatus::MOVED;
        }
 
        return SubChunkExplorerStatus::OK;
    }
 
    public function moveToChunk(int $chunkX, int $chunkY, int $chunkZ) : int{
        //this is a cold path, so we don't care much if it's a bit slower (extra fcall overhead)
        return $this->moveTo($chunkX << SubChunk::COORD_BIT_SIZE, $chunkY << SubChunk::COORD_BIT_SIZE, $chunkZ << SubChunk::COORD_BIT_SIZE);
    }
 
    public function isValid() : bool{
        return $this->currentSubChunk !== null;
    }
 
    public function invalidate() : void{
        $this->currentChunk = null;
        $this->currentSubChunk = null;
    }
}