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

package net.minecraft.world.level.block;

import com.mojang.serialization.MapCodec;
import java.util.List;
import net.minecraft.core.BlockPos;
import net.minecraft.core.Direction;
import net.minecraft.server.level.ServerLevel;
import net.minecraft.sounds.SoundEvents;
import net.minecraft.sounds.SoundSource;
import net.minecraft.util.RandomSource;
import net.minecraft.world.InteractionResult;
import net.minecraft.world.entity.decoration.ItemFrame;
import net.minecraft.world.entity.player.Player;
import net.minecraft.world.level.BlockGetter;
import net.minecraft.world.level.Level;
import net.minecraft.world.level.LevelAccessor;
import net.minecraft.world.level.block.entity.BlockEntity;
import net.minecraft.world.level.block.entity.ComparatorBlockEntity;
import net.minecraft.world.level.block.state.BlockBehaviour;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraft.world.level.block.state.StateDefinition;
import net.minecraft.world.level.block.state.properties.BlockStateProperties;
import net.minecraft.world.level.block.state.properties.ComparatorMode;
import net.minecraft.world.level.block.state.properties.EnumProperty;
import net.minecraft.world.phys.AABB;
import net.minecraft.world.phys.BlockHitResult;
import net.minecraft.world.ticks.TickPriority;
import org.jetbrains.annotations.Nullable;

public class ComparatorBlock extends DiodeBlock implements EntityBlock {
	public static final MapCodec<ComparatorBlock> CODEC = simpleCodec(ComparatorBlock::new);
	public static final EnumProperty<ComparatorMode> MODE = BlockStateProperties.MODE_COMPARATOR;

	@Override
	public MapCodec<ComparatorBlock> codec() {
		return CODEC;
	}

	public ComparatorBlock(BlockBehaviour.Properties properties) {
		super(properties);
		this.registerDefaultState(this.stateDefinition.any().setValue(FACING, Direction.NORTH).setValue(POWERED, false).setValue(MODE, ComparatorMode.COMPARE));
	}

	@Override
	protected int getDelay(BlockState state) {
		return 2;
	}

	@Override
	public BlockState updateShape(BlockState state, Direction direction, BlockState neighborState, LevelAccessor level, BlockPos pos, BlockPos neighborPos) {
		return direction == Direction.DOWN && !this.canSurviveOn(level, neighborPos, neighborState)
			? Blocks.AIR.defaultBlockState()
			: super.updateShape(state, direction, neighborState, level, pos, neighborPos);
	}

	@Override
	protected int getOutputSignal(BlockGetter level, BlockPos pos, BlockState state) {
		BlockEntity blockEntity = level.getBlockEntity(pos);
		return blockEntity instanceof ComparatorBlockEntity ? ((ComparatorBlockEntity)blockEntity).getOutputSignal() : 0;
	}

	private int calculateOutputSignal(Level level, BlockPos pos, BlockState state) {
		int i = this.getInputSignal(level, pos, state);
		if (i == 0) {
			return 0;
		} else {
			int j = this.getAlternateSignal(level, pos, state);
			if (j > i) {
				return 0;
			} else {
				return state.getValue(MODE) == ComparatorMode.SUBTRACT ? i - j : i;
			}
		}
	}

	@Override
	protected boolean shouldTurnOn(Level level, BlockPos pos, BlockState state) {
		int i = this.getInputSignal(level, pos, state);
		if (i == 0) {
			return false;
		} else {
			int j = this.getAlternateSignal(level, pos, state);
			return i > j ? true : i == j && state.getValue(MODE) == ComparatorMode.COMPARE;
		}
	}

	@Override
	protected int getInputSignal(Level level, BlockPos pos, BlockState state) {
		int i = super.getInputSignal(level, pos, state);
		Direction direction = state.getValue(FACING);
		BlockPos blockPos = pos.relative(direction);
		BlockState blockState = level.getBlockState(blockPos);
		if (blockState.hasAnalogOutputSignal()) {
			i = blockState.getAnalogOutputSignal(level, blockPos);
		} else if (i < 15 && blockState.isRedstoneConductor(level, blockPos)) {
			blockPos = blockPos.relative(direction);
			blockState = level.getBlockState(blockPos);
			ItemFrame itemFrame = this.getItemFrame(level, direction, blockPos);
			int j = Math.max(
				itemFrame == null ? Integer.MIN_VALUE : itemFrame.getAnalogOutput(),
				blockState.hasAnalogOutputSignal() ? blockState.getAnalogOutputSignal(level, blockPos) : Integer.MIN_VALUE
			);
			if (j != Integer.MIN_VALUE) {
				i = j;
			}
		}

		return i;
	}

	@Nullable
	private ItemFrame getItemFrame(Level level, Direction facing, BlockPos pos) {
		List<ItemFrame> list = level.getEntitiesOfClass(
			ItemFrame.class,
			new AABB(pos.getX(), pos.getY(), pos.getZ(), pos.getX() + 1, pos.getY() + 1, pos.getZ() + 1),
			itemFrame -> itemFrame != null && itemFrame.getDirection() == facing
		);
		return list.size() == 1 ? (ItemFrame)list.get(0) : null;
	}

	@Override
	protected InteractionResult useWithoutItem(BlockState state, Level level, BlockPos pos, Player player, BlockHitResult hitResult) {
		if (!player.getAbilities().mayBuild) {
			return InteractionResult.PASS;
		} else {
			state = state.cycle(MODE);
			float f = state.getValue(MODE) == ComparatorMode.SUBTRACT ? 0.55F : 0.5F;
			level.playSound(player, pos, SoundEvents.COMPARATOR_CLICK, SoundSource.BLOCKS, 0.3F, f);
			level.setBlock(pos, state, 2);
			this.refreshOutputState(level, pos, state);
			return InteractionResult.sidedSuccess(level.isClientSide);
		}
	}

	@Override
	protected void checkTickOnNeighbor(Level level, BlockPos pos, BlockState state) {
		if (!level.getBlockTicks().willTickThisTick(pos, this)) {
			int i = this.calculateOutputSignal(level, pos, state);
			BlockEntity blockEntity = level.getBlockEntity(pos);
			int j = blockEntity instanceof ComparatorBlockEntity ? ((ComparatorBlockEntity)blockEntity).getOutputSignal() : 0;
			if (i != j || (Boolean)state.getValue(POWERED) != this.shouldTurnOn(level, pos, state)) {
				TickPriority tickPriority = this.shouldPrioritize(level, pos, state) ? TickPriority.HIGH : TickPriority.NORMAL;
				level.scheduleTick(pos, this, 2, tickPriority);
			}
		}
	}

	private void refreshOutputState(Level level, BlockPos pos, BlockState state) {
		int i = this.calculateOutputSignal(level, pos, state);
		BlockEntity blockEntity = level.getBlockEntity(pos);
		int j = 0;
		if (blockEntity instanceof ComparatorBlockEntity comparatorBlockEntity) {
			j = comparatorBlockEntity.getOutputSignal();
			comparatorBlockEntity.setOutputSignal(i);
		}

		if (j != i || state.getValue(MODE) == ComparatorMode.COMPARE) {
			boolean bl = this.shouldTurnOn(level, pos, state);
			boolean bl2 = (Boolean)state.getValue(POWERED);
			if (bl2 && !bl) {
				level.setBlock(pos, state.setValue(POWERED, false), 2);
			} else if (!bl2 && bl) {
				level.setBlock(pos, state.setValue(POWERED, true), 2);
			}

			this.updateNeighborsInFront(level, pos, state);
		}
	}

	@Override
	protected void tick(BlockState state, ServerLevel level, BlockPos pos, RandomSource random) {
		this.refreshOutputState(level, pos, state);
	}

	@Override
	protected boolean triggerEvent(BlockState state, Level level, BlockPos pos, int id, int param) {
		super.triggerEvent(state, level, pos, id, param);
		BlockEntity blockEntity = level.getBlockEntity(pos);
		return blockEntity != null && blockEntity.triggerEvent(id, param);
	}

	@Override
	public BlockEntity newBlockEntity(BlockPos pos, BlockState state) {
		return new ComparatorBlockEntity(pos, state);
	}

	@Override
	protected void createBlockStateDefinition(StateDefinition.Builder<Block, BlockState> builder) {
		builder.add(FACING, MODE, POWERED);
	}
}