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

package net.minecraft.world.level.block;

import com.mojang.serialization.MapCodec;
import net.minecraft.advancements.CriteriaTriggers;
import net.minecraft.core.BlockPos;
import net.minecraft.core.particles.BlockParticleOption;
import net.minecraft.core.particles.ParticleTypes;
import net.minecraft.server.level.ServerPlayer;
import net.minecraft.sounds.SoundEvents;
import net.minecraft.world.entity.Entity;
import net.minecraft.world.entity.InsideBlockEffectApplier;
import net.minecraft.world.entity.LivingEntity;
import net.minecraft.world.entity.item.PrimedTnt;
import net.minecraft.world.entity.vehicle.AbstractBoat;
import net.minecraft.world.entity.vehicle.AbstractMinecart;
import net.minecraft.world.level.BlockGetter;
import net.minecraft.world.level.Level;
import net.minecraft.world.level.block.state.BlockBehaviour;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraft.world.phys.Vec3;
import net.minecraft.world.phys.shapes.CollisionContext;
import net.minecraft.world.phys.shapes.VoxelShape;

public class HoneyBlock extends HalfTransparentBlock {
	public static final MapCodec<HoneyBlock> CODEC = simpleCodec(HoneyBlock::new);
	private static final double SLIDE_STARTS_WHEN_VERTICAL_SPEED_IS_AT_LEAST = 0.13;
	private static final double MIN_FALL_SPEED_TO_BE_CONSIDERED_SLIDING = 0.08;
	private static final double THROTTLE_SLIDE_SPEED_TO = 0.05;
	private static final int SLIDE_ADVANCEMENT_CHECK_INTERVAL = 20;
	private static final VoxelShape SHAPE = Block.column(14.0, 0.0, 15.0);

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

	public HoneyBlock(BlockBehaviour.Properties properties) {
		super(properties);
	}

	private static boolean doesEntityDoHoneyBlockSlideEffects(Entity entity) {
		return entity instanceof LivingEntity || entity instanceof AbstractMinecart || entity instanceof PrimedTnt || entity instanceof AbstractBoat;
	}

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

	@Override
	public void fallOn(Level level, BlockState state, BlockPos pos, Entity entity, double fallDistance) {
		entity.playSound(SoundEvents.HONEY_BLOCK_SLIDE, 1.0F, 1.0F);
		if (!level.isClientSide) {
			level.broadcastEntityEvent(entity, (byte)54);
		}

		if (entity.causeFallDamage(fallDistance, 0.2F, level.damageSources().fall())) {
			entity.playSound(this.soundType.getFallSound(), this.soundType.getVolume() * 0.5F, this.soundType.getPitch() * 0.75F);
		}
	}

	@Override
	protected void entityInside(BlockState state, Level level, BlockPos pos, Entity entity, InsideBlockEffectApplier effectApplier) {
		if (this.isSlidingDown(pos, entity)) {
			this.maybeDoSlideAchievement(entity, pos);
			this.doSlideMovement(entity);
			this.maybeDoSlideEffects(level, entity);
		}

		super.entityInside(state, level, pos, entity, effectApplier);
	}

	private static double getOldDeltaY(double deltaY) {
		return deltaY / 0.98F + 0.08;
	}

	private static double getNewDeltaY(double deltaY) {
		return (deltaY - 0.08) * 0.98F;
	}

	private boolean isSlidingDown(BlockPos pos, Entity entity) {
		if (entity.onGround()) {
			return false;
		} else if (entity.getY() > pos.getY() + 0.9375 - 1.0E-7) {
			return false;
		} else if (getOldDeltaY(entity.getDeltaMovement().y) >= -0.08) {
			return false;
		} else {
			double d = Math.abs(pos.getX() + 0.5 - entity.getX());
			double e = Math.abs(pos.getZ() + 0.5 - entity.getZ());
			double f = 0.4375 + entity.getBbWidth() / 2.0F;
			return d + 1.0E-7 > f || e + 1.0E-7 > f;
		}
	}

	private void maybeDoSlideAchievement(Entity entity, BlockPos pos) {
		if (entity instanceof ServerPlayer && entity.level().getGameTime() % 20L == 0L) {
			CriteriaTriggers.HONEY_BLOCK_SLIDE.trigger((ServerPlayer)entity, entity.level().getBlockState(pos));
		}
	}

	private void doSlideMovement(Entity entity) {
		Vec3 vec3 = entity.getDeltaMovement();
		if (getOldDeltaY(entity.getDeltaMovement().y) < -0.13) {
			double d = -0.05 / getOldDeltaY(entity.getDeltaMovement().y);
			entity.setDeltaMovement(new Vec3(vec3.x * d, getNewDeltaY(-0.05), vec3.z * d));
		} else {
			entity.setDeltaMovement(new Vec3(vec3.x, getNewDeltaY(-0.05), vec3.z));
		}

		entity.resetFallDistance();
	}

	private void maybeDoSlideEffects(Level level, Entity entity) {
		if (doesEntityDoHoneyBlockSlideEffects(entity)) {
			if (level.random.nextInt(5) == 0) {
				entity.playSound(SoundEvents.HONEY_BLOCK_SLIDE, 1.0F, 1.0F);
			}

			if (!level.isClientSide && level.random.nextInt(5) == 0) {
				level.broadcastEntityEvent(entity, (byte)53);
			}
		}
	}

	public static void showSlideParticles(Entity entity) {
		showParticles(entity, 5);
	}

	public static void showJumpParticles(Entity entity) {
		showParticles(entity, 10);
	}

	private static void showParticles(Entity entity, int particleCount) {
		if (entity.level().isClientSide) {
			BlockState blockState = Blocks.HONEY_BLOCK.defaultBlockState();

			for (int i = 0; i < particleCount; i++) {
				entity.level().addParticle(new BlockParticleOption(ParticleTypes.BLOCK, blockState), entity.getX(), entity.getY(), entity.getZ(), 0.0, 0.0, 0.0);
			}
		}
	}
}