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

package net.minecraft.world.level.levelgen;

import com.mojang.serialization.Codec;
import javax.annotation.Nullable;
import net.minecraft.core.Holder;
import net.minecraft.core.registries.Registries;
import net.minecraft.resources.RegistryFileCodec;
import net.minecraft.util.KeyDispatchDataCodec;
import net.minecraft.world.level.levelgen.blending.Blender;
import net.minecraft.world.level.levelgen.synth.NormalNoise;

public interface DensityFunction {
    Codec<DensityFunction> DIRECT_CODEC = DensityFunctions.DIRECT_CODEC;
    Codec<Holder<DensityFunction>> CODEC = RegistryFileCodec.create(Registries.DENSITY_FUNCTION, DIRECT_CODEC);
    Codec<DensityFunction> HOLDER_HELPER_CODEC = CODEC.xmap(
        DensityFunctions.HolderHolder::new,
        p_208226_ -> (Holder<DensityFunction>)(p_208226_ instanceof DensityFunctions.HolderHolder densityfunctions$holderholder
            ? densityfunctions$holderholder.function()
            : new Holder.Direct<>(p_208226_))
    );

    double compute(DensityFunction.FunctionContext p_208223_);

    void fillArray(double[] p_208227_, DensityFunction.ContextProvider p_208228_);

    DensityFunction mapAll(DensityFunction.Visitor p_208224_);

    double minValue();

    double maxValue();

    KeyDispatchDataCodec<? extends DensityFunction> codec();

    default DensityFunction clamp(double p_208221_, double p_208222_) {
        return new DensityFunctions.Clamp(this, p_208221_, p_208222_);
    }

    default DensityFunction abs() {
        return DensityFunctions.map(this, DensityFunctions.Mapped.Type.ABS);
    }

    default DensityFunction square() {
        return DensityFunctions.map(this, DensityFunctions.Mapped.Type.SQUARE);
    }

    default DensityFunction cube() {
        return DensityFunctions.map(this, DensityFunctions.Mapped.Type.CUBE);
    }

    default DensityFunction halfNegative() {
        return DensityFunctions.map(this, DensityFunctions.Mapped.Type.HALF_NEGATIVE);
    }

    default DensityFunction quarterNegative() {
        return DensityFunctions.map(this, DensityFunctions.Mapped.Type.QUARTER_NEGATIVE);
    }

    default DensityFunction squeeze() {
        return DensityFunctions.map(this, DensityFunctions.Mapped.Type.SQUEEZE);
    }

    public interface ContextProvider {
        DensityFunction.FunctionContext forIndex(int p_208235_);

        void fillAllDirectly(double[] p_208236_, DensityFunction p_208237_);
    }

    public interface FunctionContext {
        int blockX();

        int blockY();

        int blockZ();

        default Blender getBlender() {
            return Blender.empty();
        }
    }

    public record NoiseHolder(Holder<NormalNoise.NoiseParameters> noiseData, @Nullable NormalNoise noise) {
        public static final Codec<DensityFunction.NoiseHolder> CODEC = NormalNoise.NoiseParameters.CODEC
            .xmap(p_224011_ -> new DensityFunction.NoiseHolder((Holder<NormalNoise.NoiseParameters>)p_224011_, null), DensityFunction.NoiseHolder::noiseData);

        public NoiseHolder(Holder<NormalNoise.NoiseParameters> p_224001_) {
            this(p_224001_, null);
        }

        public double getValue(double p_224007_, double p_224008_, double p_224009_) {
            return this.noise == null ? 0.0 : this.noise.getValue(p_224007_, p_224008_, p_224009_);
        }

        public double maxValue() {
            return this.noise == null ? 2.0 : this.noise.maxValue();
        }
    }

    public interface SimpleFunction extends DensityFunction {
        @Override
        default void fillArray(double[] p_208241_, DensityFunction.ContextProvider p_208242_) {
            p_208242_.fillAllDirectly(p_208241_, this);
        }

        @Override
        default DensityFunction mapAll(DensityFunction.Visitor p_208239_) {
            return p_208239_.apply(this);
        }
    }

    public record SinglePointContext(int blockX, int blockY, int blockZ) implements DensityFunction.FunctionContext {
        @Override
        public int blockX() {
            return this.blockX;
        }

        @Override
        public int blockY() {
            return this.blockY;
        }

        @Override
        public int blockZ() {
            return this.blockZ;
        }
    }

    public interface Visitor {
        DensityFunction apply(DensityFunction p_224019_);

        default DensityFunction.NoiseHolder visitNoise(DensityFunction.NoiseHolder p_224018_) {
            return p_224018_;
        }
    }
}