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

package net.minecraft.world.level.block;

import com.mojang.serialization.MapCodec;
import net.minecraft.core.BlockPos;
import net.minecraft.core.Direction;
import net.minecraft.server.level.ServerLevel;
import net.minecraft.tags.BlockTags;
import net.minecraft.tags.FluidTags;
import net.minecraft.util.RandomSource;
import net.minecraft.world.entity.Entity;
import net.minecraft.world.entity.LivingEntity;
import net.minecraft.world.entity.player.Player;
import net.minecraft.world.item.context.BlockPlaceContext;
import net.minecraft.world.level.BlockGetter;
import net.minecraft.world.level.GameRules;
import net.minecraft.world.level.Level;
import net.minecraft.world.level.LevelAccessor;
import net.minecraft.world.level.LevelReader;
import net.minecraft.world.level.block.piston.MovingPistonBlock;
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.IntegerProperty;
import net.minecraft.world.level.gameevent.GameEvent;
import net.minecraft.world.level.pathfinder.PathComputationType;
import net.minecraft.world.phys.shapes.CollisionContext;
import net.minecraft.world.phys.shapes.VoxelShape;
import org.jetbrains.annotations.Nullable;

public class FarmBlock extends Block {
	public static final MapCodec<FarmBlock> CODEC = simpleCodec(FarmBlock::new);
	public static final IntegerProperty MOISTURE = BlockStateProperties.MOISTURE;
	protected static final VoxelShape SHAPE = Block.box(0.0, 0.0, 0.0, 16.0, 15.0, 16.0);
	public static final int MAX_MOISTURE = 7;

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

	protected FarmBlock(BlockBehaviour.Properties properties) {
		super(properties);
		this.registerDefaultState(this.stateDefinition.any().setValue(MOISTURE, 0));
	}

	@Override
	protected BlockState updateShape(BlockState state, Direction direction, BlockState neighborState, LevelAccessor level, BlockPos pos, BlockPos neighborPos) {
		if (direction == Direction.UP && !state.canSurvive(level, pos)) {
			level.scheduleTick(pos, this, 1);
		}

		return super.updateShape(state, direction, neighborState, level, pos, neighborPos);
	}

	@Override
	protected boolean canSurvive(BlockState state, LevelReader level, BlockPos pos) {
		BlockState blockState = level.getBlockState(pos.above());
		return !blockState.isSolid() || blockState.getBlock() instanceof FenceGateBlock || blockState.getBlock() instanceof MovingPistonBlock;
	}

	@Override
	public BlockState getStateForPlacement(BlockPlaceContext context) {
		return !this.defaultBlockState().canSurvive(context.getLevel(), context.getClickedPos())
			? Blocks.DIRT.defaultBlockState()
			: super.getStateForPlacement(context);
	}

	@Override
	protected boolean useShapeForLightOcclusion(BlockState state) {
		return true;
	}

	@Override
	protected VoxelShape getShape(BlockState state, BlockGetter level, BlockPos pos, CollisionContext context) {
		return SHAPE;
	}

	@Override
	protected void tick(BlockState state, ServerLevel level, BlockPos pos, RandomSource random) {
		if (!state.canSurvive(level, pos)) {
			turnToDirt(null, state, level, pos);
		}
	}

	@Override
	protected void randomTick(BlockState state, ServerLevel level, BlockPos pos, RandomSource random) {
		int i = (Integer)state.getValue(MOISTURE);
		if (!isNearWater(level, pos) && !level.isRainingAt(pos.above())) {
			if (i > 0) {
				level.setBlock(pos, state.setValue(MOISTURE, i - 1), 2);
			} else if (!shouldMaintainFarmland(level, pos)) {
				turnToDirt(null, state, level, pos);
			}
		} else if (i < 7) {
			level.setBlock(pos, state.setValue(MOISTURE, 7), 2);
		}
	}

	@Override
	public void fallOn(Level level, BlockState state, BlockPos pos, Entity entity, float fallDistance) {
		if (!level.isClientSide
			&& level.random.nextFloat() < fallDistance - 0.5F
			&& entity instanceof LivingEntity
			&& (entity instanceof Player || level.getGameRules().getBoolean(GameRules.RULE_MOBGRIEFING))
			&& entity.getBbWidth() * entity.getBbWidth() * entity.getBbHeight() > 0.512F) {
			turnToDirt(entity, state, level, pos);
		}

		super.fallOn(level, state, pos, entity, fallDistance);
	}

	public static void turnToDirt(@Nullable Entity entity, BlockState state, Level level, BlockPos pos) {
		BlockState blockState = pushEntitiesUp(state, Blocks.DIRT.defaultBlockState(), level, pos);
		level.setBlockAndUpdate(pos, blockState);
		level.gameEvent(GameEvent.BLOCK_CHANGE, pos, GameEvent.Context.of(entity, blockState));
	}

	private static boolean shouldMaintainFarmland(BlockGetter level, BlockPos pos) {
		return level.getBlockState(pos.above()).is(BlockTags.MAINTAINS_FARMLAND);
	}

	private static boolean isNearWater(LevelReader level, BlockPos pos) {
		for (BlockPos blockPos : BlockPos.betweenClosed(pos.offset(-4, 0, -4), pos.offset(4, 1, 4))) {
			if (level.getFluidState(blockPos).is(FluidTags.WATER)) {
				return true;
			}
		}

		return false;
	}

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

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