minecraft-src/net/minecraft/world/level/levelgen/structure/structures/JigsawStructure.java

package net.minecraft.world.level.levelgen.structure.structures;

import com.google.common.annotations.VisibleForTesting;
import com.mojang.serialization.Codec;
import com.mojang.serialization.DataResult;
import com.mojang.serialization.MapCodec;
import com.mojang.serialization.codecs.RecordCodecBuilder;
import java.util.List;
import java.util.Optional;
import net.minecraft.core.BlockPos;
import net.minecraft.core.Holder;
import net.minecraft.resources.ResourceLocation;
import net.minecraft.world.level.ChunkPos;
import net.minecraft.world.level.levelgen.Heightmap;
import net.minecraft.world.level.levelgen.WorldGenerationContext;
import net.minecraft.world.level.levelgen.heightproviders.HeightProvider;
import net.minecraft.world.level.levelgen.structure.Structure;
import net.minecraft.world.level.levelgen.structure.StructureType;
import net.minecraft.world.level.levelgen.structure.Structure.GenerationContext;
import net.minecraft.world.level.levelgen.structure.Structure.GenerationStub;
import net.minecraft.world.level.levelgen.structure.Structure.StructureSettings;
import net.minecraft.world.level.levelgen.structure.pools.DimensionPadding;
import net.minecraft.world.level.levelgen.structure.pools.JigsawPlacement;
import net.minecraft.world.level.levelgen.structure.pools.StructureTemplatePool;
import net.minecraft.world.level.levelgen.structure.pools.alias.PoolAliasBinding;
import net.minecraft.world.level.levelgen.structure.pools.alias.PoolAliasLookup;
import net.minecraft.world.level.levelgen.structure.templatesystem.LiquidSettings;

public final class JigsawStructure extends Structure {
	public static final DimensionPadding DEFAULT_DIMENSION_PADDING = DimensionPadding.ZERO;
	public static final LiquidSettings DEFAULT_LIQUID_SETTINGS = LiquidSettings.APPLY_WATERLOGGING;
	public static final int MAX_TOTAL_STRUCTURE_RANGE = 128;
	public static final int MIN_DEPTH = 0;
	public static final int MAX_DEPTH = 20;
	public static final MapCodec<JigsawStructure> CODEC = RecordCodecBuilder.<JigsawStructure>mapCodec(
			instance -> instance.group(
					settingsCodec(instance),
					StructureTemplatePool.CODEC.fieldOf("start_pool").forGetter(jigsawStructure -> jigsawStructure.startPool),
					ResourceLocation.CODEC.optionalFieldOf("start_jigsaw_name").forGetter(jigsawStructure -> jigsawStructure.startJigsawName),
					Codec.intRange(0, 20).fieldOf("size").forGetter(jigsawStructure -> jigsawStructure.maxDepth),
					HeightProvider.CODEC.fieldOf("start_height").forGetter(jigsawStructure -> jigsawStructure.startHeight),
					Codec.BOOL.fieldOf("use_expansion_hack").forGetter(jigsawStructure -> jigsawStructure.useExpansionHack),
					Heightmap.Types.CODEC.optionalFieldOf("project_start_to_heightmap").forGetter(jigsawStructure -> jigsawStructure.projectStartToHeightmap),
					Codec.intRange(1, 128).fieldOf("max_distance_from_center").forGetter(jigsawStructure -> jigsawStructure.maxDistanceFromCenter),
					Codec.list(PoolAliasBinding.CODEC).optionalFieldOf("pool_aliases", List.of()).forGetter(jigsawStructure -> jigsawStructure.poolAliases),
					DimensionPadding.CODEC.optionalFieldOf("dimension_padding", DEFAULT_DIMENSION_PADDING).forGetter(jigsawStructure -> jigsawStructure.dimensionPadding),
					LiquidSettings.CODEC.optionalFieldOf("liquid_settings", DEFAULT_LIQUID_SETTINGS).forGetter(jigsawStructure -> jigsawStructure.liquidSettings)
				)
				.apply(instance, JigsawStructure::new)
		)
		.validate(JigsawStructure::verifyRange);
	private final Holder<StructureTemplatePool> startPool;
	private final Optional<ResourceLocation> startJigsawName;
	private final int maxDepth;
	private final HeightProvider startHeight;
	private final boolean useExpansionHack;
	private final Optional<Heightmap.Types> projectStartToHeightmap;
	private final int maxDistanceFromCenter;
	private final List<PoolAliasBinding> poolAliases;
	private final DimensionPadding dimensionPadding;
	private final LiquidSettings liquidSettings;

	private static DataResult<JigsawStructure> verifyRange(JigsawStructure structure) {
		int i = switch (structure.terrainAdaptation()) {
			case NONE -> 0;
			case BURY, BEARD_THIN, BEARD_BOX, ENCAPSULATE -> 12;
		};
		return structure.maxDistanceFromCenter + i > 128
			? DataResult.error(() -> "Structure size including terrain adaptation must not exceed 128")
			: DataResult.success(structure);
	}

	public JigsawStructure(
		StructureSettings settings,
		Holder<StructureTemplatePool> startPool,
		Optional<ResourceLocation> startJigsawName,
		int maxDepth,
		HeightProvider startHeight,
		boolean useExpansionHack,
		Optional<Heightmap.Types> projectStartToHeightmap,
		int maxDistanceFromCenter,
		List<PoolAliasBinding> poolAliases,
		DimensionPadding dimensionPadding,
		LiquidSettings liquidSettings
	) {
		super(settings);
		this.startPool = startPool;
		this.startJigsawName = startJigsawName;
		this.maxDepth = maxDepth;
		this.startHeight = startHeight;
		this.useExpansionHack = useExpansionHack;
		this.projectStartToHeightmap = projectStartToHeightmap;
		this.maxDistanceFromCenter = maxDistanceFromCenter;
		this.poolAliases = poolAliases;
		this.dimensionPadding = dimensionPadding;
		this.liquidSettings = liquidSettings;
	}

	public JigsawStructure(
		StructureSettings settings,
		Holder<StructureTemplatePool> startPool,
		int maxDepth,
		HeightProvider startHeight,
		boolean useExpansionHack,
		Heightmap.Types projectStartToHeightmap
	) {
		this(
			settings,
			startPool,
			Optional.empty(),
			maxDepth,
			startHeight,
			useExpansionHack,
			Optional.of(projectStartToHeightmap),
			80,
			List.of(),
			DEFAULT_DIMENSION_PADDING,
			DEFAULT_LIQUID_SETTINGS
		);
	}

	public JigsawStructure(StructureSettings settings, Holder<StructureTemplatePool> startPool, int maxDepth, HeightProvider startHeight, boolean useExpansionHack) {
		this(
			settings,
			startPool,
			Optional.empty(),
			maxDepth,
			startHeight,
			useExpansionHack,
			Optional.empty(),
			80,
			List.of(),
			DEFAULT_DIMENSION_PADDING,
			DEFAULT_LIQUID_SETTINGS
		);
	}

	@Override
	public Optional<GenerationStub> findGenerationPoint(GenerationContext context) {
		ChunkPos chunkPos = context.chunkPos();
		int i = this.startHeight.sample(context.random(), new WorldGenerationContext(context.chunkGenerator(), context.heightAccessor()));
		BlockPos blockPos = new BlockPos(chunkPos.getMinBlockX(), i, chunkPos.getMinBlockZ());
		return JigsawPlacement.addPieces(
			context,
			this.startPool,
			this.startJigsawName,
			this.maxDepth,
			blockPos,
			this.useExpansionHack,
			this.projectStartToHeightmap,
			this.maxDistanceFromCenter,
			PoolAliasLookup.create(this.poolAliases, blockPos, context.seed()),
			this.dimensionPadding,
			this.liquidSettings
		);
	}

	@Override
	public StructureType<?> type() {
		return StructureType.JIGSAW;
	}

	@VisibleForTesting
	public Holder<StructureTemplatePool> getStartPool() {
		return this.startPool;
	}

	@VisibleForTesting
	public List<PoolAliasBinding> getPoolAliases() {
		return this.poolAliases;
	}
}