src/game/java/net/minecraft/client/renderer/PostChainConfig.java

package net.minecraft.client.renderer;

import com.mojang.blaze3d.vertex.DefaultVertexFormat;
import com.mojang.datafixers.util.Either;
import com.mojang.serialization.Codec;
import com.mojang.serialization.DataResult;
import com.mojang.serialization.codecs.RecordCodecBuilder;
import com.mojang.serialization.codecs.RecordCodecBuilder.Instance;
import it.unimi.dsi.fastutil.objects.ObjectArraySet;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.function.Function;
import net.minecraft.resources.ResourceLocation;
import net.minecraft.util.ExtraCodecs;
import net.minecraftforge.api.distmarker.Dist;
import net.minecraftforge.api.distmarker.OnlyIn;

@OnlyIn(Dist.CLIENT)
public record PostChainConfig(Map<ResourceLocation, PostChainConfig.InternalTarget> internalTargets, List<PostChainConfig.Pass> passes) {
    public static final Codec<PostChainConfig> CODEC = RecordCodecBuilder.create(
        p_362023_ -> p_362023_.group(
                    Codec.unboundedMap(ResourceLocation.CODEC, PostChainConfig.InternalTarget.CODEC)
                        .optionalFieldOf("targets", Map.of())
                        .forGetter(PostChainConfig::internalTargets),
                    PostChainConfig.Pass.CODEC.listOf().optionalFieldOf("passes", List.of()).forGetter(PostChainConfig::passes)
                )
                .apply(p_362023_, PostChainConfig::new)
    );

    @OnlyIn(Dist.CLIENT)
    public static record FixedSizedTarget(int width, int height) implements PostChainConfig.InternalTarget {
        public static final Codec<PostChainConfig.FixedSizedTarget> CODEC = RecordCodecBuilder.create(
            p_363084_ -> p_363084_.group(
                        ExtraCodecs.POSITIVE_INT.fieldOf("width").forGetter(PostChainConfig.FixedSizedTarget::width),
                        ExtraCodecs.POSITIVE_INT.fieldOf("height").forGetter(PostChainConfig.FixedSizedTarget::height)
                    )
                    .apply(p_363084_, PostChainConfig.FixedSizedTarget::new)
        );
    }

    @OnlyIn(Dist.CLIENT)
    public static record FullScreenTarget() implements PostChainConfig.InternalTarget {
        public static final Codec<PostChainConfig.FullScreenTarget> CODEC = Codec.unit(PostChainConfig.FullScreenTarget::new);
    }

    @OnlyIn(Dist.CLIENT)
    public sealed interface Input permits PostChainConfig.TextureInput, PostChainConfig.TargetInput {
        Codec<PostChainConfig.Input> CODEC = Codec.xor(PostChainConfig.TextureInput.CODEC, PostChainConfig.TargetInput.CODEC)
            .xmap(p_368743_ -> p_368743_.map(Function.identity(), Function.identity()), p_368212_ -> {
                Objects.requireNonNull(p_368212_);

                return switch (p_368212_) {
                    case PostChainConfig.TextureInput postchainconfig$textureinput -> Either.left(postchainconfig$textureinput);
                    case PostChainConfig.TargetInput postchainconfig$targetinput -> Either.right(postchainconfig$targetinput);
                    default -> throw new MatchException(null, null);
                };
            });

        String samplerName();

        Set<ResourceLocation> referencedTargets();
    }

    @OnlyIn(Dist.CLIENT)
    public sealed interface InternalTarget permits PostChainConfig.FullScreenTarget, PostChainConfig.FixedSizedTarget {
        Codec<PostChainConfig.InternalTarget> CODEC = Codec.either(PostChainConfig.FixedSizedTarget.CODEC, PostChainConfig.FullScreenTarget.CODEC)
            .xmap(p_364357_ -> p_364357_.map(Function.identity(), Function.identity()), p_362739_ -> {
                Objects.requireNonNull(p_362739_);

                return switch (p_362739_) {
                    case PostChainConfig.FixedSizedTarget postchainconfig$fixedsizedtarget -> Either.left(postchainconfig$fixedsizedtarget);
                    case PostChainConfig.FullScreenTarget postchainconfig$fullscreentarget -> Either.right(postchainconfig$fullscreentarget);
                    default -> throw new MatchException(null, null);
                };
            });
    }

    @OnlyIn(Dist.CLIENT)
    public static record Pass(
        ResourceLocation programId, List<PostChainConfig.Input> inputs, ResourceLocation outputTarget, List<PostChainConfig.Uniform> uniforms
    ) {
        private static final Codec<List<PostChainConfig.Input>> INPUTS_CODEC = PostChainConfig.Input.CODEC.listOf().validate(p_363610_ -> {
            Set<String> set = new ObjectArraySet<>(p_363610_.size());

            for (PostChainConfig.Input postchainconfig$input : p_363610_) {
                if (!set.add(postchainconfig$input.samplerName())) {
                    return DataResult.error(() -> "Encountered repeated sampler name: " + postchainconfig$input.samplerName());
                }
            }

            return DataResult.success(p_363610_);
        });
        public static final Codec<PostChainConfig.Pass> CODEC = RecordCodecBuilder.create(
            p_369989_ -> p_369989_.group(
                        ResourceLocation.CODEC.fieldOf("program").forGetter(PostChainConfig.Pass::programId),
                        INPUTS_CODEC.optionalFieldOf("inputs", List.of()).forGetter(PostChainConfig.Pass::inputs),
                        ResourceLocation.CODEC.fieldOf("output").forGetter(PostChainConfig.Pass::outputTarget),
                        PostChainConfig.Uniform.CODEC.listOf().optionalFieldOf("uniforms", List.of()).forGetter(PostChainConfig.Pass::uniforms)
                    )
                    .apply(p_369989_, PostChainConfig.Pass::new)
        );

        public ShaderProgram program() {
            return new ShaderProgram(this.programId, DefaultVertexFormat.POSITION, ShaderDefines.EMPTY);
        }
    }

    @OnlyIn(Dist.CLIENT)
    public static record TargetInput(String samplerName, ResourceLocation targetId, boolean useDepthBuffer, boolean bilinear) implements PostChainConfig.Input {
        public static final Codec<PostChainConfig.TargetInput> CODEC = RecordCodecBuilder.create(
            p_361775_ -> p_361775_.group(
                        Codec.STRING.fieldOf("sampler_name").forGetter(PostChainConfig.TargetInput::samplerName),
                        ResourceLocation.CODEC.fieldOf("target").forGetter(PostChainConfig.TargetInput::targetId),
                        Codec.BOOL.optionalFieldOf("use_depth_buffer", Boolean.valueOf(false)).forGetter(PostChainConfig.TargetInput::useDepthBuffer),
                        Codec.BOOL.optionalFieldOf("bilinear", Boolean.valueOf(false)).forGetter(PostChainConfig.TargetInput::bilinear)
                    )
                    .apply(p_361775_, PostChainConfig.TargetInput::new)
        );

        @Override
        public Set<ResourceLocation> referencedTargets() {
            return Set.of(this.targetId);
        }

        @Override
        public String samplerName() {
            return this.samplerName;
        }
    }

    @OnlyIn(Dist.CLIENT)
    public static record TextureInput(String samplerName, ResourceLocation location, int width, int height, boolean bilinear)
        implements PostChainConfig.Input {
        public static final Codec<PostChainConfig.TextureInput> CODEC = RecordCodecBuilder.create(
            p_368377_ -> p_368377_.group(
                        Codec.STRING.fieldOf("sampler_name").forGetter(PostChainConfig.TextureInput::samplerName),
                        ResourceLocation.CODEC.fieldOf("location").forGetter(PostChainConfig.TextureInput::location),
                        ExtraCodecs.POSITIVE_INT.fieldOf("width").forGetter(PostChainConfig.TextureInput::width),
                        ExtraCodecs.POSITIVE_INT.fieldOf("height").forGetter(PostChainConfig.TextureInput::height),
                        Codec.BOOL.optionalFieldOf("bilinear", Boolean.valueOf(false)).forGetter(PostChainConfig.TextureInput::bilinear)
                    )
                    .apply(p_368377_, PostChainConfig.TextureInput::new)
        );

        @Override
        public Set<ResourceLocation> referencedTargets() {
            return Set.of();
        }

        @Override
        public String samplerName() {
            return this.samplerName;
        }
    }

    @OnlyIn(Dist.CLIENT)
    public static record Uniform(String name, List<Float> values) {
        public static final Codec<PostChainConfig.Uniform> CODEC = RecordCodecBuilder.create(
            p_361485_ -> p_361485_.group(
                        Codec.STRING.fieldOf("name").forGetter(PostChainConfig.Uniform::name),
                        Codec.FLOAT.sizeLimitedListOf(4).fieldOf("values").forGetter(PostChainConfig.Uniform::values)
                    )
                    .apply(p_361485_, PostChainConfig.Uniform::new)
        );
    }
}