Normal.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\generator\normal;
 
use pocketmine\block\Block;
use pocketmine\block\VanillaBlocks;
use pocketmine\data\bedrock\BiomeIds;
use pocketmine\utils\AssumptionFailedError;
use pocketmine\world\biome\Biome;
use pocketmine\world\biome\BiomeRegistry;
use pocketmine\world\ChunkManager;
use pocketmine\world\format\Chunk;
use pocketmine\world\format\PalettedBlockArray;
use pocketmine\world\format\SubChunk;
use pocketmine\world\generator\biome\BiomeSelector;
use pocketmine\world\generator\Gaussian;
use pocketmine\world\generator\Generator;
use pocketmine\world\generator\InvalidGeneratorOptionsException;
use pocketmine\world\generator\noise\Simplex;
use pocketmine\world\generator\object\OreType;
use pocketmine\world\generator\populator\GroundCover;
use pocketmine\world\generator\populator\Ore;
use pocketmine\world\generator\populator\Populator;
use pocketmine\world\World;
use function ceil;
use function floor;
use function fmod;
use function is_int;
use function max;
use function min;
 
class Normal extends Generator{
 
    private int $waterHeight = 62;
    private array $populators = [];
    private array $generationPopulators = [];
    private Simplex $noiseBase;
    private BiomeSelector $selector;
    private Gaussian $gaussian;
 
    private const NOISE_SAMPLING_RATE_Y = 8;
 
    public function __construct(int $seed, string $preset){
        parent::__construct($seed, $preset);
 
        $this->gaussian = new Gaussian(2);
 
        $this->noiseBase = new Simplex($this->random, 4, 1 / 4, 1 / 32);
        $this->random->setSeed($this->seed);
 
        $this->selector = new class($this->random) extends BiomeSelector{
            protected function lookup(float $temperature, float $rainfall) : int{
                if($rainfall < 0.25){
                    if($temperature < 0.7){
                        return BiomeIds::OCEAN;
                    }elseif($temperature < 0.85){
                        return BiomeIds::RIVER;
                    }else{
                        return BiomeIds::SWAMPLAND;
                    }
                }elseif($rainfall < 0.60){
                    if($temperature < 0.25){
                        return BiomeIds::ICE_PLAINS;
                    }elseif($temperature < 0.75){
                        return BiomeIds::PLAINS;
                    }else{
                        return BiomeIds::DESERT;
                    }
                }elseif($rainfall < 0.80){
                    if($temperature < 0.25){
                        return BiomeIds::TAIGA;
                    }elseif($temperature < 0.75){
                        return BiomeIds::FOREST;
                    }else{
                        return BiomeIds::BIRCH_FOREST;
                    }
                }else{
                    if($temperature < 0.20){
                        return BiomeIds::EXTREME_HILLS;
                    }elseif($temperature < 0.40){
                        return BiomeIds::EXTREME_HILLS_EDGE;
                    }else{
                        return BiomeIds::RIVER;
                    }
                }
            }
        };
 
        $this->selector->recalculate();
 
        $cover = new GroundCover();
        $this->generationPopulators[] = $cover;
 
        $ores = new Ore();
        $stone = VanillaBlocks::STONE();
        $ores->setOreTypes([
            new OreType(VanillaBlocks::COAL_ORE(), $stone, 20, 16, 0, 128),
            new OreType(VanillaBlocks::IRON_ORE(), $stone, 20, 8, 0, 64),
            new OreType(VanillaBlocks::REDSTONE_ORE(), $stone, 8, 7, 0, 16),
            new OreType(VanillaBlocks::LAPIS_LAZULI_ORE(), $stone, 1, 6, 0, 32),
            new OreType(VanillaBlocks::GOLD_ORE(), $stone, 2, 8, 0, 32),
            new OreType(VanillaBlocks::DIAMOND_ORE(), $stone, 1, 7, 0, 16),
            new OreType(VanillaBlocks::DIRT(), $stone, 20, 32, 0, 128),
            new OreType(VanillaBlocks::GRAVEL(), $stone, 10, 16, 0, 128)
        ]);
        $this->populators[] = $ores;
    }
 
    private function pickBiome(int $x, int $z) : Biome{
        $hash = $x * 2345803 ^ $z * 9236449 ^ $this->seed;
        $hash *= $hash + 223;
        //the above operations may result in a float. This probably wasn't intended, but we need to stick with it to
        //avoid cliff edges in existing user worlds.
        //We need to mod this so it doesn't generate an error in PHP 8.5 when we cast it back to an int.
        $hash = (int) fmod($hash, 2.0 ** 63);
        $xNoise = $hash >> 20 & 3;
        $zNoise = $hash >> 22 & 3;
        if($xNoise === 3){
            $xNoise = 1;
        }
        if($zNoise === 3){
            $zNoise = 1;
        }
 
        return $this->selector->pickBiome($x + $xNoise - 1, $z + $zNoise - 1);
    }
 
    public function generateChunk(ChunkManager $world, int $chunkX, int $chunkZ) : void{
        $this->random->setSeed(0xdeadbeef ^ ($chunkX << 8) ^ $chunkZ ^ $this->seed);
 
        //TODO: why don't we just create and set the chunk here directly?
        $chunk = $world->getChunk($chunkX, $chunkZ) ?? throw new \InvalidArgumentException("Chunk $chunkX $chunkZ does not yet exist");
 
        $bedrock = VanillaBlocks::BEDROCK()->getStateId();
        $stillWater = VanillaBlocks::WATER()->getStateId();
        $stone = VanillaBlocks::STONE()->getStateId();
 
        $baseX = $chunkX * Chunk::EDGE_LENGTH;
        $baseZ = $chunkZ * Chunk::EDGE_LENGTH;
 
        [$biomeArray, $minNoiseHeights, $maxNoiseHeights] = $this->generateBiomes($baseX, $baseZ);
 
        $lowestNoiseBlock = (int) floor(min($minNoiseHeights));
        $highestNoiseBlock = (int) ceil(max($maxNoiseHeights));
 
        //getFastNoise3D expects the inputs to be aligned with the sampling rate, otherwise the samples will be taken
        //from different coordinates than we originally used when we first implemented this generator
        $noiseMin = (int) floor($lowestNoiseBlock / self::NOISE_SAMPLING_RATE_Y) * self::NOISE_SAMPLING_RATE_Y;
        $noiseMax = (int) ceil($highestNoiseBlock / self::NOISE_SAMPLING_RATE_Y) * self::NOISE_SAMPLING_RATE_Y;
 
        //we only need to generate noise for the blocks which could be affected
        //outside these bounds we'll just flood-fill blocks to save time
        $noise = $this->noiseBase->getFastNoise3D(
            xSize: Chunk::EDGE_LENGTH,
            ySize: $noiseMax - $noiseMin,
            zSize: Chunk::EDGE_LENGTH,
            xSamplingRate: 4,
            ySamplingRate: self::NOISE_SAMPLING_RATE_Y,
            zSamplingRate: 4,
            x: $chunkX * Chunk::EDGE_LENGTH,
            y: $noiseMin,
            z: $chunkZ * Chunk::EDGE_LENGTH
        );
 
        $minNoiseSubChunk = (int) floor($noiseMin / SubChunk::EDGE_LENGTH);
        foreach($chunk->getSubChunks() as $y => $subChunk){
            if($y >= 0 && $y < $minNoiseSubChunk){
                //Everything above 0 and below noiseMin is always solid stone, which can be flood-filled instead of
                //setting the blocks one at a time - this is vastly faster
                $fillId = $stone;
            }else{
                $fillId = Block::EMPTY_STATE_ID;
            }
            $chunk->setSubChunk($y, new SubChunk(Block::EMPTY_STATE_ID, new PalettedBlockArray($fillId), null, clone $biomeArray));
        }
 
        for($x = 0; $x < Chunk::EDGE_LENGTH; ++$x){
            for($z = 0; $z < Chunk::EDGE_LENGTH; ++$z){
                $chunk->setBlockStateId($x, 0, $z, $bedrock);
 
                $columnIndex = World::chunkHash($x, $z);
                $minSum = $minNoiseHeights[$columnIndex];
                $maxSum = $maxNoiseHeights[$columnIndex];
                $maxBlockY = max($maxSum, $this->waterHeight);
                $smoothHeight = ($maxSum - $minSum) / 2;
 
                //Everything below minSum is always solid stone - we already flood-filled the subchunks below though, so
                //we only need to fill the gap in the column here
                for($y = $minNoiseSubChunk * SubChunk::EDGE_LENGTH; $y < $minSum; $y++){
                    $chunk->setBlockStateId($x, $y, $z, $stone);
                }
                for($y = (int) floor($minSum); $y <= $maxBlockY; ++$y){
                    //noiseValue would anyway be <= 0 above maxSum because the smoothing term is >= 1
                    $noiseValue = $y > $noiseMax ?
                        -1 :
                        $noise[$x][$z][$y - $noiseMin] - 1 / $smoothHeight * ($y - $smoothHeight - $minSum);
 
                    if($noiseValue > 0){
                        $chunk->setBlockStateId($x, $y, $z, $stone);
                    }elseif($y <= $this->waterHeight){
                        $chunk->setBlockStateId($x, $y, $z, $stillWater);
                    }
                }
            }
        }
 
        foreach($this->generationPopulators as $populator){
            $populator->populate($world, $chunkX, $chunkZ, $this->random);
        }
    }
 
    public function populateChunk(ChunkManager $world, int $chunkX, int $chunkZ) : void{
        $this->random->setSeed(0xdeadbeef ^ ($chunkX << 8) ^ $chunkZ ^ $this->seed);
        foreach($this->populators as $populator){
            $populator->populate($world, $chunkX, $chunkZ, $this->random);
        }
 
        $chunk = $world->getChunk($chunkX, $chunkZ);
        $biome = BiomeRegistry::getInstance()->getBiome($chunk->getBiomeId(7, 7, 7));
        $biome->populateChunk($world, $chunkX, $chunkZ, $this->random);
    }
 
    private function generateBiomes(int $baseX, int $baseZ) : array{
        $biomeCache = [];
 
        $biomeArray = new PalettedBlockArray(BiomeIds::OCEAN);
 
        $uniform = null;
        $padding = $this->gaussian->smoothSize;
        $start = -$padding;
        $end = Chunk::EDGE_LENGTH + $padding;
        for($x = $start; $x < $end; ++$x){
            $absoluteX = $baseX + $x;
            for($z = $start; $z < $end; ++$z){
                $absoluteZ = $baseZ + $z;
 
                $columnIndex = World::chunkHash($x, $z);
                $biome = $biomeCache[$columnIndex] = $this->pickBiome($absoluteX, $absoluteZ);
                $biomeId = $biome->getId();
                $uniform = match ($uniform) {
                    null, $biomeId => $biomeId,
                    default => false
                };
 
                if($x >= 0 && $x < Chunk::EDGE_LENGTH && $z >= 0 && $z < Chunk::EDGE_LENGTH){
                    for($y = 0; $y < 16; $y++){
                        $biomeArray->set($x, $y, $z, $biomeId);
                    }
                }
            }
        }
 
        if($uniform === false){
            [$minHeights, $maxHeights] = $this->gaussianSmoothElevation($start, $end, $biomeCache);
        }else{
            //If all the biomes in the blurred area are the same, we can save some performance by skipping blurring
            //With the current generator as of 2025-10-23, blurring can be skipped in two-thirds of chunks
            if(!is_int($uniform)){
                throw new AssumptionFailedError();
            }
            $biome = BiomeRegistry::getInstance()->getBiome($uniform);
            $minHeights = [];
            $maxHeights = [];
 
            $minElevation = $biome->getMinElevation() - 1;
            $maxElevation = $biome->getMaxElevation();
            for($x = 0; $x < Chunk::EDGE_LENGTH; $x++){
                for($z = 0; $z < Chunk::EDGE_LENGTH; $z++){
                    $columnIndex = World::chunkHash($x, $z);
                    $minHeights[$columnIndex] = $minElevation;
                    $maxHeights[$columnIndex] = $maxElevation;
                }
            }
        }
 
        return [$biomeArray, $minHeights, $maxHeights];
    }
 
    private function gaussianSmoothElevation(int $start, int $end, array $biomeCache) : array{
        $minHeightsX = [];
        $maxHeightsX = [];
        //blur along the X axis first
        for($x = 0; $x < Chunk::EDGE_LENGTH; $x++){
            //while we don't need to smooth the padding corners, we do need to make sure that the contributions of
            //those corners are included in Z padding, otherwise we can get artifacts at chunk corners
            for($z = $start; $z < $end; $z++){
                $columnIndex = World::chunkHash($x, $z);
 
                $minSum = 0;
                $maxSum = 0;
 
                for($sx = -$this->gaussian->smoothSize; $sx <= $this->gaussian->smoothSize; ++$sx){
                    $weight = $this->gaussian->kernel1D[$sx + $this->gaussian->smoothSize];
                    $adjacent = $biomeCache[World::chunkHash($x + $sx, $z)];
 
                    $minSum += ($adjacent->getMinElevation() - 1) * $weight;
                    $maxSum += $adjacent->getMaxElevation() * $weight;
                }
 
                $minHeightsX[$columnIndex] = $minSum / $this->gaussian->weightSum1D;
                $maxHeightsX[$columnIndex] = $maxSum / $this->gaussian->weightSum1D;
            }
        }
 
        $minHeights = [];
        $maxHeights = [];
 
        //then the Z axis, using the blurred values from the previous loop
        for($x = 0; $x < Chunk::EDGE_LENGTH; $x++){
            for($z = 0; $z < Chunk::EDGE_LENGTH; $z++){
                $columnIndex = World::chunkHash($x, $z);
 
                $minSum = 0;
                $maxSum = 0;
 
                for($sx = -$this->gaussian->smoothSize; $sx <= $this->gaussian->smoothSize; ++$sx){
                    $weight = $this->gaussian->kernel1D[$sx + $this->gaussian->smoothSize];
                    $adjacentIndex = World::chunkHash($x, $z + $sx);
                    $minElevation = $minHeightsX[$adjacentIndex];
                    $maxElevation = $maxHeightsX[$adjacentIndex];
 
                    $minSum += $minElevation * $weight;
                    $maxSum += $maxElevation * $weight;
                }
 
                $minHeights[$columnIndex] = $minSum / $this->gaussian->weightSum1D;
                $maxHeights[$columnIndex] = $maxSum / $this->gaussian->weightSum1D;
            }
        }
 
        return [$minHeights, $maxHeights];
    }
}