SubChunk.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\format;
 
class SubChunk{
    public const COORD_BIT_SIZE = 4;
    public const COORD_MASK = ~(~0 << self::COORD_BIT_SIZE);
    public const EDGE_LENGTH = 1 << self::COORD_BIT_SIZE;
 
    public function __construct(
        private int $emptyBlockId,
        private ?PalettedBlockArray $blockLayer0,
        private ?PalettedBlockArray $blockLayer1,
        private PalettedBlockArray $biomes,
        private ?LightArray $skyLight = null,
        private ?LightArray $blockLight = null
    ){}
 
    public function isEmptyAuthoritative() : bool{
        $this->collectGarbage();
        return $this->isEmptyFast();
    }
 
    public function isEmptyFast() : bool{
        return $this->blockLayer0 === null && $this->blockLayer1 === null;
    }
 
    public function getEmptyBlockId() : int{ return $this->emptyBlockId; }
 
    public function getBlockStateId(int $x, int $y, int $z) : int{
        return $this->blockLayer0?->get($x, $y, $z) ?? $this->emptyBlockId;
    }
 
    public function setBlockStateId(int $x, int $y, int $z, int $block) : void{
        if($this->blockLayer0 === null){
            $this->blockLayer0 = new PalettedBlockArray($this->emptyBlockId);
        }
        $this->blockLayer0->set($x, $y, $z, $block);
    }
 
    public function getBlockLayer0() : ?PalettedBlockArray{
        return $this->blockLayer0;
    }
 
    public function getBlockLayer1() : ?PalettedBlockArray{
        return $this->blockLayer1;
    }
 
    public function getBlockLayers() : array{
        $layers = [];
        if($this->blockLayer0 !== null){
            $layers[] = $this->blockLayer0;
        }
        if($this->blockLayer1 !== null){
            $layers[] = $this->blockLayer1;
        }
        return $layers;
    }
 
    public function getHighestBlockAt(int $x, int $z) : ?int{
        if($this->blockLayer0 === null){
            return null;
        }
        for($y = self::EDGE_LENGTH - 1; $y >= 0; --$y){
            if($this->blockLayer0->get($x, $y, $z) !== $this->emptyBlockId){
                return $y;
            }
        }
 
        return null; //highest block not in this subchunk
    }
 
    public function getBiomeArray() : PalettedBlockArray{ return $this->biomes; }
 
    public function getBlockSkyLightArray() : LightArray{
        return $this->skyLight ??= LightArray::fill(0);
    }
 
    public function setBlockSkyLightArray(LightArray $data) : void{
        $this->skyLight = $data;
    }
 
    public function getBlockLightArray() : LightArray{
        return $this->blockLight ??= LightArray::fill(0);
    }
 
    public function setBlockLightArray(LightArray $data) : void{
        $this->blockLight = $data;
    }
 
    public function __debugInfo() : array{
        return [];
    }
 
    private static function gcBlockPalette(?PalettedBlockArray $layer, int $emptyBlockId) : ?PalettedBlockArray{
        if($layer === null){
            return null;
        }
        $layer->collectGarbage();
        return $layer->getBitsPerBlock() === 0 && $layer->get(0, 0, 0) === $emptyBlockId ? null : $layer;
    }
 
    public function collectGarbage() : void{
        $this->blockLayer0 = self::gcBlockPalette($this->blockLayer0, $this->emptyBlockId);
        $this->blockLayer1 = self::gcBlockPalette($this->blockLayer1, $this->emptyBlockId);
        if($this->blockLayer0 === null && $this->blockLayer1 !== null){
            $this->blockLayer0 = $this->blockLayer1;
            $this->blockLayer1 = null;
        }
        $this->biomes->collectGarbage();
 
        if($this->skyLight !== null && $this->skyLight->isUniform(0)){
            $this->skyLight = null;
        }
        if($this->blockLight !== null && $this->blockLight->isUniform(0)){
            $this->blockLight = null;
        }
    }
 
    public function __clone(){
        $this->blockLayer0 = $this->blockLayer0 !== null ? clone $this->blockLayer0 : null;
        $this->blockLayer1 = $this->blockLayer1 !== null ? clone $this->blockLayer1 : null;
        $this->biomes = clone $this->biomes;
 
        if($this->skyLight !== null){
            $this->skyLight = clone $this->skyLight;
        }
        if($this->blockLight !== null){
            $this->blockLight = clone $this->blockLight;
        }
    }
}