BlockLightUpdate.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\light;
 
use pocketmine\world\format\LightArray;
use pocketmine\world\format\PalettedBlockArray;
use pocketmine\world\format\SubChunk;
use pocketmine\world\utils\SubChunkExplorer;
use pocketmine\world\utils\SubChunkExplorerStatus;
use function max;
 
class BlockLightUpdate extends LightUpdate{
    public function __construct(
        SubChunkExplorer $subChunkExplorer,
        array $lightFilters,
        private array $lightEmitters
    ){
        parent::__construct($subChunkExplorer, $lightFilters);
    }
 
    protected function getCurrentLightArray() : LightArray{
        return $this->subChunkExplorer->currentSubChunk->getBlockLightArray();
    }
 
    public function recalculateNode(int $x, int $y, int $z) : void{
        if($this->subChunkExplorer->moveTo($x, $y, $z) !== SubChunkExplorerStatus::INVALID){
            $block = $this->subChunkExplorer->currentSubChunk->getBlockStateId($x & SubChunk::COORD_MASK, $y & SubChunk::COORD_MASK, $z & SubChunk::COORD_MASK);
            $this->setAndUpdateLight($x, $y, $z, max($this->lightEmitters[$block] ?? 0, $this->getHighestAdjacentLight($x, $y, $z) - ($this->lightFilters[$block] ?? self::BASE_LIGHT_FILTER)));
        }
    }
 
    private function layerHasLightEmitter(?PalettedBlockArray $layer) : bool{
        if($layer === null){
            return false;
        }
 
        foreach($layer->getPalette() as $state){
            if(($this->lightEmitters[$state] ?? 0) > 0){
                return true;
            }
        }
 
        return false;
    }
 
    public function recalculateChunk(int $chunkX, int $chunkZ) : int{
        if($this->subChunkExplorer->moveToChunk($chunkX, 0, $chunkZ) === SubChunkExplorerStatus::INVALID){
            throw new \InvalidArgumentException("Chunk $chunkX $chunkZ does not exist");
        }
        $chunk = $this->subChunkExplorer->currentChunk;
 
        $lightSources = 0;
        foreach($chunk->getSubChunks() as $subChunkY => $subChunk){
            $subChunk->setBlockLightArray(LightArray::fill(0));
 
            if(
                $this->layerHasLightEmitter($subChunk->getBlockLayer0()) ||
                $this->layerHasLightEmitter($subChunk->getBlockLayer1())
            ){
                $lightSources += $this->scanForLightEmittingBlocks($subChunk, $chunkX << SubChunk::COORD_BIT_SIZE, $subChunkY << SubChunk::COORD_BIT_SIZE, $chunkZ << SubChunk::COORD_BIT_SIZE);
            }
        }
 
        return $lightSources;
    }
 
    private function scanForLightEmittingBlocks(SubChunk $subChunk, int $baseX, int $baseY, int $baseZ) : int{
        $lightSources = 0;
        for($x = 0; $x < SubChunk::EDGE_LENGTH; ++$x){
            for($z = 0; $z < SubChunk::EDGE_LENGTH; ++$z){
                for($y = 0; $y < SubChunk::EDGE_LENGTH; ++$y){
                    $light = $this->lightEmitters[$subChunk->getBlockStateId($x, $y, $z)] ?? 0;
                    if($light > 0){
                        $this->setAndUpdateLight(
                            $baseX + $x,
                            $baseY + $y,
                            $baseZ + $z,
                            $light
                        );
                        $lightSources++;
                    }
                }
            }
        }
        return $lightSources;
    }
}