minecraft-src/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.Sampler;
import net.minecraft.world.level.levelgen.synth.BlendedNoise;
import net.minecraft.world.level.levelgen.synth.NormalNoise;
import net.minecraft.world.level.levelgen.synth.NormalNoise.NoiseParameters;

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

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

	public static RandomState create(NoiseGeneratorSettings settings, HolderGetter<NoiseParameters> noiseParametersGetter, long levelSeed) {
		return new RandomState(settings, noiseParametersGetter, levelSeed);
	}

	private RandomState(NoiseGeneratorSettings settings, HolderGetter<NoiseParameters> noiseParametersGetter, long levelSeed) {
		this.random = settings.getRandomSource().newInstance(levelSeed).forkPositional();
		this.noises = noiseParametersGetter;
		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, settings.defaultBlock(), settings.seaLevel(), this.random);
		final boolean bl = settings.useLegacyRandomSource();

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

			private RandomSource newLegacyInstance(long seed) {
				return new LegacyRandomSource(levelSeed + seed);
			}

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

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

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

				NormalNoise normalNoise = RandomState.this.getOrCreateNoise((ResourceKey<NoiseParameters>)holder.unwrapKey().orElseThrow());
				return new DensityFunction.NoiseHolder(holder, normalNoise);
			}

			private DensityFunction wrapNew(DensityFunction densityFunction) {
				if (densityFunction instanceof BlendedNoise blendedNoise) {
					RandomSource randomSource = bl ? this.newLegacyInstance(0L) : RandomState.this.random.fromHashOf(ResourceLocation.withDefaultNamespace("terrain"));
					return blendedNoise.withNewRandom(randomSource);
				} else {
					return (DensityFunction)(densityFunction instanceof DensityFunctions.EndIslandDensityFunction
						? new DensityFunctions.EndIslandDensityFunction(levelSeed)
						: densityFunction);
				}
			}

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

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

			private DensityFunction wrapNew(DensityFunction densityFunction) {
				if (densityFunction instanceof DensityFunctions.HolderHolder holderHolder) {
					return holderHolder.function().value();
				} else {
					return densityFunction instanceof DensityFunctions.Marker marker ? marker.wrapped() : densityFunction;
				}
			}

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

	public NormalNoise getOrCreateNoise(ResourceKey<NoiseParameters> resourceKey) {
		return (NormalNoise)this.noiseIntances.computeIfAbsent(resourceKey, resourceKey2 -> Noises.instantiate(this.noises, this.random, resourceKey));
	}

	public PositionalRandomFactory getOrCreateRandomFactory(ResourceLocation location) {
		return (PositionalRandomFactory)this.positionalRandoms.computeIfAbsent(location, resourceLocation2 -> this.random.fromHashOf(location).forkPositional());
	}

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

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

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

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

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