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

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

import com.google.common.collect.ImmutableMap;
import java.util.Map;
import net.minecraft.core.BlockPos;
import net.minecraft.core.Vec3i;
import net.minecraft.nbt.CompoundTag;
import net.minecraft.resources.ResourceLocation;
import net.minecraft.util.RandomSource;
import net.minecraft.world.level.ChunkPos;
import net.minecraft.world.level.ServerLevelAccessor;
import net.minecraft.world.level.StructureManager;
import net.minecraft.world.level.WorldGenLevel;
import net.minecraft.world.level.block.Blocks;
import net.minecraft.world.level.block.Mirror;
import net.minecraft.world.level.block.Rotation;
import net.minecraft.world.level.block.entity.BlockEntity;
import net.minecraft.world.level.block.entity.ChestBlockEntity;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraft.world.level.chunk.ChunkGenerator;
import net.minecraft.world.level.levelgen.Heightmap;
import net.minecraft.world.level.levelgen.structure.BoundingBox;
import net.minecraft.world.level.levelgen.structure.StructurePieceAccessor;
import net.minecraft.world.level.levelgen.structure.TemplateStructurePiece;
import net.minecraft.world.level.levelgen.structure.pieces.StructurePieceSerializationContext;
import net.minecraft.world.level.levelgen.structure.pieces.StructurePieceType;
import net.minecraft.world.level.levelgen.structure.templatesystem.BlockIgnoreProcessor;
import net.minecraft.world.level.levelgen.structure.templatesystem.LiquidSettings;
import net.minecraft.world.level.levelgen.structure.templatesystem.StructurePlaceSettings;
import net.minecraft.world.level.levelgen.structure.templatesystem.StructureTemplate;
import net.minecraft.world.level.levelgen.structure.templatesystem.StructureTemplateManager;
import net.minecraft.world.level.storage.loot.BuiltInLootTables;

public class IglooPieces {
	public static final int GENERATION_HEIGHT = 90;
	static final ResourceLocation STRUCTURE_LOCATION_IGLOO = ResourceLocation.withDefaultNamespace("igloo/top");
	private static final ResourceLocation STRUCTURE_LOCATION_LADDER = ResourceLocation.withDefaultNamespace("igloo/middle");
	private static final ResourceLocation STRUCTURE_LOCATION_LABORATORY = ResourceLocation.withDefaultNamespace("igloo/bottom");
	static final Map<ResourceLocation, BlockPos> PIVOTS = ImmutableMap.of(
		STRUCTURE_LOCATION_IGLOO, new BlockPos(3, 5, 5), STRUCTURE_LOCATION_LADDER, new BlockPos(1, 3, 1), STRUCTURE_LOCATION_LABORATORY, new BlockPos(3, 6, 7)
	);
	static final Map<ResourceLocation, BlockPos> OFFSETS = ImmutableMap.of(
		STRUCTURE_LOCATION_IGLOO, BlockPos.ZERO, STRUCTURE_LOCATION_LADDER, new BlockPos(2, -3, 4), STRUCTURE_LOCATION_LABORATORY, new BlockPos(0, -3, -2)
	);

	public static void addPieces(
		StructureTemplateManager structureTemplateManager, BlockPos startPos, Rotation rotation, StructurePieceAccessor pieces, RandomSource random
	) {
		if (random.nextDouble() < 0.5) {
			int i = random.nextInt(8) + 4;
			pieces.addPiece(new IglooPieces.IglooPiece(structureTemplateManager, STRUCTURE_LOCATION_LABORATORY, startPos, rotation, i * 3));

			for (int j = 0; j < i - 1; j++) {
				pieces.addPiece(new IglooPieces.IglooPiece(structureTemplateManager, STRUCTURE_LOCATION_LADDER, startPos, rotation, j * 3));
			}
		}

		pieces.addPiece(new IglooPieces.IglooPiece(structureTemplateManager, STRUCTURE_LOCATION_IGLOO, startPos, rotation, 0));
	}

	public static class IglooPiece extends TemplateStructurePiece {
		public IglooPiece(StructureTemplateManager structureTemplateManager, ResourceLocation location, BlockPos startPos, Rotation rotation, int down) {
			super(
				StructurePieceType.IGLOO,
				0,
				structureTemplateManager,
				location,
				location.toString(),
				makeSettings(rotation, location),
				makePosition(location, startPos, down)
			);
		}

		public IglooPiece(StructureTemplateManager structureTemplateManager, CompoundTag tag) {
			super(
				StructurePieceType.IGLOO,
				tag,
				structureTemplateManager,
				resourceLocation -> makeSettings((Rotation)tag.read("Rot", Rotation.LEGACY_CODEC).orElseThrow(), resourceLocation)
			);
		}

		private static StructurePlaceSettings makeSettings(Rotation rotation, ResourceLocation location) {
			return new StructurePlaceSettings()
				.setRotation(rotation)
				.setMirror(Mirror.NONE)
				.setRotationPivot((BlockPos)IglooPieces.PIVOTS.get(location))
				.addProcessor(BlockIgnoreProcessor.STRUCTURE_BLOCK)
				.setLiquidSettings(LiquidSettings.IGNORE_WATERLOGGING);
		}

		private static BlockPos makePosition(ResourceLocation location, BlockPos pos, int down) {
			return pos.offset((Vec3i)IglooPieces.OFFSETS.get(location)).below(down);
		}

		@Override
		protected void addAdditionalSaveData(StructurePieceSerializationContext context, CompoundTag tag) {
			super.addAdditionalSaveData(context, tag);
			tag.store("Rot", Rotation.LEGACY_CODEC, this.placeSettings.getRotation());
		}

		@Override
		protected void handleDataMarker(String name, BlockPos pos, ServerLevelAccessor level, RandomSource random, BoundingBox box) {
			if ("chest".equals(name)) {
				level.setBlock(pos, Blocks.AIR.defaultBlockState(), 3);
				BlockEntity blockEntity = level.getBlockEntity(pos.below());
				if (blockEntity instanceof ChestBlockEntity) {
					((ChestBlockEntity)blockEntity).setLootTable(BuiltInLootTables.IGLOO_CHEST, random.nextLong());
				}
			}
		}

		@Override
		public void postProcess(
			WorldGenLevel level, StructureManager structureManager, ChunkGenerator generator, RandomSource random, BoundingBox box, ChunkPos chunkPos, BlockPos pos
		) {
			ResourceLocation resourceLocation = ResourceLocation.parse(this.templateName);
			StructurePlaceSettings structurePlaceSettings = makeSettings(this.placeSettings.getRotation(), resourceLocation);
			BlockPos blockPos = (BlockPos)IglooPieces.OFFSETS.get(resourceLocation);
			BlockPos blockPos2 = this.templatePosition
				.offset(StructureTemplate.calculateRelativePosition(structurePlaceSettings, new BlockPos(3 - blockPos.getX(), 0, -blockPos.getZ())));
			int i = level.getHeight(Heightmap.Types.WORLD_SURFACE_WG, blockPos2.getX(), blockPos2.getZ());
			BlockPos blockPos3 = this.templatePosition;
			this.templatePosition = this.templatePosition.offset(0, i - 90 - 1, 0);
			super.postProcess(level, structureManager, generator, random, box, chunkPos, pos);
			if (resourceLocation.equals(IglooPieces.STRUCTURE_LOCATION_IGLOO)) {
				BlockPos blockPos4 = this.templatePosition.offset(StructureTemplate.calculateRelativePosition(structurePlaceSettings, new BlockPos(3, 0, 5)));
				BlockState blockState = level.getBlockState(blockPos4.below());
				if (!blockState.isAir() && !blockState.is(Blocks.LADDER)) {
					level.setBlock(blockPos4, Blocks.SNOW_BLOCK.defaultBlockState(), 3);
				}
			}

			this.templatePosition = blockPos3;
		}
	}
}