Code/net/minecraft/world/level/levelgen/RandomState.java

package net.minecraft.world.level.levelgen;

import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import net.minecraft.core.Holder;
import net.minecraft.core.HolderGetter;
import net.minecraft.core.registries.Registries;
import net.minecraft.resources.ResourceKey;
import net.minecraft.resources.ResourceLocation;
import net.minecraft.util.RandomSource;
import net.minecraft.world.level.biome.Climate;
import net.minecraft.world.level.levelgen.synth.BlendedNoise;
import net.minecraft.world.level.levelgen.synth.NormalNoise;

public final class RandomState {
    final PositionalRandomFactory random;
    private final HolderGetter<NormalNoise.NoiseParameters> noises;
    private final NoiseRouter router;
    private final Climate.Sampler sampler;
    private final SurfaceSystem surfaceSystem;
    private final PositionalRandomFactory aquiferRandom;
    private final PositionalRandomFactory oreRandom;
    private final Map<ResourceKey<NormalNoise.NoiseParameters>, NormalNoise> noiseIntances;
    private final Map<ResourceLocation, PositionalRandomFactory> positionalRandoms;

    public static RandomState create(HolderGetter.Provider p_255935_, ResourceKey<NoiseGeneratorSettings> p_256314_, long p_256595_) {
        return create(p_255935_.lookupOrThrow(Registries.NOISE_SETTINGS).getOrThrow(p_256314_).value(), p_255935_.lookupOrThrow(Registries.NOISE), p_256595_);
    }

    public static RandomState create(NoiseGeneratorSettings p_255761_, HolderGetter<NormalNoise.NoiseParameters> p_256649_, long p_255965_) {
        return new RandomState(p_255761_, p_256649_, p_255965_);
    }

    private RandomState(NoiseGeneratorSettings p_255668_, HolderGetter<NormalNoise.NoiseParameters> p_256663_, final long p_255691_) {
        this.random = p_255668_.getRandomSource().newInstance(p_255691_).forkPositional();
        this.noises = p_256663_;
        this.aquiferRandom = this.random.fromHashOf(ResourceLocation.withDefaultNamespace("aquifer")).forkPositional();
        this.oreRandom = this.random.fromHashOf(ResourceLocation.withDefaultNamespace("ore")).forkPositional();
        this.noiseIntances = new ConcurrentHashMap<>();
        this.positionalRandoms = new ConcurrentHashMap<>();
        this.surfaceSystem = new SurfaceSystem(this, p_255668_.defaultBlock(), p_255668_.seaLevel(), this.random);
        final boolean flag = p_255668_.useLegacyRandomSource();

        class NoiseWiringHelper implements DensityFunction.Visitor {
            private final Map<DensityFunction, DensityFunction> wrapped = new HashMap<>();

            private RandomSource newLegacyInstance(long p_224592_) {
                return new LegacyRandomSource(p_255691_ + p_224592_);
            }

            @Override
            public DensityFunction.NoiseHolder visitNoise(DensityFunction.NoiseHolder p_224594_) {
                Holder<NormalNoise.NoiseParameters> holder = p_224594_.noiseData();
                if (flag) {
                    if (holder.is(Noises.TEMPERATURE)) {
                        NormalNoise normalnoise3 = NormalNoise.createLegacyNetherBiome(this.newLegacyInstance(0L), new NormalNoise.NoiseParameters(-7, 1.0, 1.0));
                        return new DensityFunction.NoiseHolder(holder, normalnoise3);
                    }

                    if (holder.is(Noises.VEGETATION)) {
                        NormalNoise normalnoise2 = NormalNoise.createLegacyNetherBiome(this.newLegacyInstance(1L), new NormalNoise.NoiseParameters(-7, 1.0, 1.0));
                        return new DensityFunction.NoiseHolder(holder, normalnoise2);
                    }

                    if (holder.is(Noises.SHIFT)) {
                        NormalNoise normalnoise1 = NormalNoise.create(
                            RandomState.this.random.fromHashOf(Noises.SHIFT.location()), new NormalNoise.NoiseParameters(0, 0.0)
                        );
                        return new DensityFunction.NoiseHolder(holder, normalnoise1);
                    }
                }

                NormalNoise normalnoise = RandomState.this.getOrCreateNoise(holder.unwrapKey().orElseThrow());
                return new DensityFunction.NoiseHolder(holder, normalnoise);
            }

            private DensityFunction wrapNew(DensityFunction p_224596_) {
                if (p_224596_ instanceof BlendedNoise blendednoise) {
                    RandomSource randomsource = flag ? this.newLegacyInstance(0L) : RandomState.this.random.fromHashOf(ResourceLocation.withDefaultNamespace("terrain"));
                    return blendednoise.withNewRandom(randomsource);
                } else {
                    return (DensityFunction)(p_224596_ instanceof DensityFunctions.EndIslandDensityFunction
                        ? new DensityFunctions.EndIslandDensityFunction(p_255691_)
                        : p_224596_);
                }
            }

            @Override
            public DensityFunction apply(DensityFunction p_224598_) {
                return this.wrapped.computeIfAbsent(p_224598_, this::wrapNew);
            }
        }

        this.router = p_255668_.noiseRouter().mapAll(new NoiseWiringHelper());
        DensityFunction.Visitor densityfunction$visitor = new DensityFunction.Visitor() {
            private final Map<DensityFunction, DensityFunction> wrapped = new HashMap<>();

            private DensityFunction wrapNew(DensityFunction p_249732_) {
                if (p_249732_ instanceof DensityFunctions.HolderHolder densityfunctions$holderholder) {
                    return densityfunctions$holderholder.function().value();
                } else {
                    return p_249732_ instanceof DensityFunctions.Marker densityfunctions$marker ? densityfunctions$marker.wrapped() : p_249732_;
                }
            }

            @Override
            public DensityFunction apply(DensityFunction p_248616_) {
                return this.wrapped.computeIfAbsent(p_248616_, this::wrapNew);
            }
        };
        this.sampler = new Climate.Sampler(
            this.router.temperature().mapAll(densityfunction$visitor),
            this.router.vegetation().mapAll(densityfunction$visitor),
            this.router.continents().mapAll(densityfunction$visitor),
            this.router.erosion().mapAll(densityfunction$visitor),
            this.router.depth().mapAll(densityfunction$visitor),
            this.router.ridges().mapAll(densityfunction$visitor),
            p_255668_.spawnTarget()
        );
    }

    public NormalNoise getOrCreateNoise(ResourceKey<NormalNoise.NoiseParameters> p_224561_) {
        return this.noiseIntances.computeIfAbsent(p_224561_, p_255589_ -> Noises.instantiate(this.noises, this.random, p_224561_));
    }

    public PositionalRandomFactory getOrCreateRandomFactory(ResourceLocation p_224566_) {
        return this.positionalRandoms.computeIfAbsent(p_224566_, p_224569_ -> this.random.fromHashOf(p_224566_).forkPositional());
    }

    public NoiseRouter router() {
        return this.router;
    }

    public Climate.Sampler sampler() {
        return this.sampler;
    }

    public SurfaceSystem surfaceSystem() {
        return this.surfaceSystem;
    }

    public PositionalRandomFactory aquiferRandom() {
        return this.aquiferRandom;
    }

    public PositionalRandomFactory oreRandom() {
        return this.oreRandom;
    }
}