minecraft-src/net/minecraft/world/level/block/CrossCollisionBlock.java

package net.minecraft.world.level.block;

import com.mojang.serialization.MapCodec;
import it.unimi.dsi.fastutil.objects.Object2IntMap;
import it.unimi.dsi.fastutil.objects.Object2IntOpenHashMap;
import java.util.Map;
import net.minecraft.Util;
import net.minecraft.core.BlockPos;
import net.minecraft.core.Direction;
import net.minecraft.world.level.BlockGetter;
import net.minecraft.world.level.block.state.BlockBehaviour;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraft.world.level.block.state.properties.BlockStateProperties;
import net.minecraft.world.level.block.state.properties.BooleanProperty;
import net.minecraft.world.level.material.FluidState;
import net.minecraft.world.level.material.Fluids;
import net.minecraft.world.level.pathfinder.PathComputationType;
import net.minecraft.world.phys.shapes.CollisionContext;
import net.minecraft.world.phys.shapes.Shapes;
import net.minecraft.world.phys.shapes.VoxelShape;

public abstract class CrossCollisionBlock extends Block implements SimpleWaterloggedBlock {
	public static final BooleanProperty NORTH = PipeBlock.NORTH;
	public static final BooleanProperty EAST = PipeBlock.EAST;
	public static final BooleanProperty SOUTH = PipeBlock.SOUTH;
	public static final BooleanProperty WEST = PipeBlock.WEST;
	public static final BooleanProperty WATERLOGGED = BlockStateProperties.WATERLOGGED;
	protected static final Map<Direction, BooleanProperty> PROPERTY_BY_DIRECTION = (Map<Direction, BooleanProperty>)PipeBlock.PROPERTY_BY_DIRECTION
		.entrySet()
		.stream()
		.filter(entry -> ((Direction)entry.getKey()).getAxis().isHorizontal())
		.collect(Util.toMap());
	protected final VoxelShape[] collisionShapeByIndex;
	protected final VoxelShape[] shapeByIndex;
	private final Object2IntMap<BlockState> stateToIndex = new Object2IntOpenHashMap<>();

	protected CrossCollisionBlock(
		float nodeWidth, float extensionWidth, float nodeHeight, float extensionHeight, float collisionHeight, BlockBehaviour.Properties properties
	) {
		super(properties);
		this.collisionShapeByIndex = this.makeShapes(nodeWidth, extensionWidth, collisionHeight, 0.0F, collisionHeight);
		this.shapeByIndex = this.makeShapes(nodeWidth, extensionWidth, nodeHeight, 0.0F, extensionHeight);

		for (BlockState blockState : this.stateDefinition.getPossibleStates()) {
			this.getAABBIndex(blockState);
		}
	}

	@Override
	protected abstract MapCodec<? extends CrossCollisionBlock> codec();

	protected VoxelShape[] makeShapes(float nodeWidth, float extensionWidth, float nodeHeight, float extensionBottom, float extensionHeight) {
		float f = 8.0F - nodeWidth;
		float g = 8.0F + nodeWidth;
		float h = 8.0F - extensionWidth;
		float i = 8.0F + extensionWidth;
		VoxelShape voxelShape = Block.box(f, 0.0, f, g, nodeHeight, g);
		VoxelShape voxelShape2 = Block.box(h, extensionBottom, 0.0, i, extensionHeight, i);
		VoxelShape voxelShape3 = Block.box(h, extensionBottom, h, i, extensionHeight, 16.0);
		VoxelShape voxelShape4 = Block.box(0.0, extensionBottom, h, i, extensionHeight, i);
		VoxelShape voxelShape5 = Block.box(h, extensionBottom, h, 16.0, extensionHeight, i);
		VoxelShape voxelShape6 = Shapes.or(voxelShape2, voxelShape5);
		VoxelShape voxelShape7 = Shapes.or(voxelShape3, voxelShape4);
		VoxelShape[] voxelShapes = new VoxelShape[]{
			Shapes.empty(),
			voxelShape3,
			voxelShape4,
			voxelShape7,
			voxelShape2,
			Shapes.or(voxelShape3, voxelShape2),
			Shapes.or(voxelShape4, voxelShape2),
			Shapes.or(voxelShape7, voxelShape2),
			voxelShape5,
			Shapes.or(voxelShape3, voxelShape5),
			Shapes.or(voxelShape4, voxelShape5),
			Shapes.or(voxelShape7, voxelShape5),
			voxelShape6,
			Shapes.or(voxelShape3, voxelShape6),
			Shapes.or(voxelShape4, voxelShape6),
			Shapes.or(voxelShape7, voxelShape6)
		};

		for (int j = 0; j < 16; j++) {
			voxelShapes[j] = Shapes.or(voxelShape, voxelShapes[j]);
		}

		return voxelShapes;
	}

	@Override
	protected boolean propagatesSkylightDown(BlockState state, BlockGetter level, BlockPos pos) {
		return !(Boolean)state.getValue(WATERLOGGED);
	}

	@Override
	protected VoxelShape getShape(BlockState state, BlockGetter level, BlockPos pos, CollisionContext context) {
		return this.shapeByIndex[this.getAABBIndex(state)];
	}

	@Override
	protected VoxelShape getCollisionShape(BlockState state, BlockGetter level, BlockPos pos, CollisionContext context) {
		return this.collisionShapeByIndex[this.getAABBIndex(state)];
	}

	private static int indexFor(Direction facing) {
		return 1 << facing.get2DDataValue();
	}

	protected int getAABBIndex(BlockState state) {
		return this.stateToIndex.computeIntIfAbsent(state, blockState -> {
			int i = 0;
			if ((Boolean)blockState.getValue(NORTH)) {
				i |= indexFor(Direction.NORTH);
			}

			if ((Boolean)blockState.getValue(EAST)) {
				i |= indexFor(Direction.EAST);
			}

			if ((Boolean)blockState.getValue(SOUTH)) {
				i |= indexFor(Direction.SOUTH);
			}

			if ((Boolean)blockState.getValue(WEST)) {
				i |= indexFor(Direction.WEST);
			}

			return i;
		});
	}

	@Override
	protected FluidState getFluidState(BlockState state) {
		return state.getValue(WATERLOGGED) ? Fluids.WATER.getSource(false) : super.getFluidState(state);
	}

	@Override
	protected boolean isPathfindable(BlockState state, PathComputationType pathComputationType) {
		return false;
	}

	@Override
	protected BlockState rotate(BlockState state, Rotation rotation) {
		switch (rotation) {
			case CLOCKWISE_180:
				return state.setValue(NORTH, (Boolean)state.getValue(SOUTH))
					.setValue(EAST, (Boolean)state.getValue(WEST))
					.setValue(SOUTH, (Boolean)state.getValue(NORTH))
					.setValue(WEST, (Boolean)state.getValue(EAST));
			case COUNTERCLOCKWISE_90:
				return state.setValue(NORTH, (Boolean)state.getValue(EAST))
					.setValue(EAST, (Boolean)state.getValue(SOUTH))
					.setValue(SOUTH, (Boolean)state.getValue(WEST))
					.setValue(WEST, (Boolean)state.getValue(NORTH));
			case CLOCKWISE_90:
				return state.setValue(NORTH, (Boolean)state.getValue(WEST))
					.setValue(EAST, (Boolean)state.getValue(NORTH))
					.setValue(SOUTH, (Boolean)state.getValue(EAST))
					.setValue(WEST, (Boolean)state.getValue(SOUTH));
			default:
				return state;
		}
	}

	@Override
	protected BlockState mirror(BlockState state, Mirror mirror) {
		switch (mirror) {
			case LEFT_RIGHT:
				return state.setValue(NORTH, (Boolean)state.getValue(SOUTH)).setValue(SOUTH, (Boolean)state.getValue(NORTH));
			case FRONT_BACK:
				return state.setValue(EAST, (Boolean)state.getValue(WEST)).setValue(WEST, (Boolean)state.getValue(EAST));
			default:
				return super.mirror(state, mirror);
		}
	}
}