src/game/java/net/minecraft/world/item/BrushItem.java

package net.minecraft.world.item;

import net.minecraft.core.BlockPos;
import net.minecraft.core.Direction;
import net.minecraft.core.particles.BlockParticleOption;
import net.minecraft.core.particles.ParticleTypes;
import net.minecraft.server.level.ServerLevel;
import net.minecraft.sounds.SoundEvent;
import net.minecraft.sounds.SoundEvents;
import net.minecraft.sounds.SoundSource;
import net.minecraft.world.InteractionHand;
import net.minecraft.world.InteractionResult;
import net.minecraft.world.entity.EntitySelector;
import net.minecraft.world.entity.EquipmentSlot;
import net.minecraft.world.entity.HumanoidArm;
import net.minecraft.world.entity.LivingEntity;
import net.minecraft.world.entity.player.Player;
import net.minecraft.world.entity.projectile.ProjectileUtil;
import net.minecraft.world.item.context.UseOnContext;
import net.minecraft.world.level.Level;
import net.minecraft.world.level.block.BrushableBlock;
import net.minecraft.world.level.block.RenderShape;
import net.minecraft.world.level.block.entity.BrushableBlockEntity;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraft.world.phys.BlockHitResult;
import net.minecraft.world.phys.HitResult;
import net.minecraft.world.phys.Vec3;

public class BrushItem extends Item {
    public static final int ANIMATION_DURATION = 10;
    private static final int USE_DURATION = 200;

    public BrushItem(Item.Properties p_272907_) {
        super(p_272907_);
    }

    @Override
    public InteractionResult useOn(UseOnContext p_272607_) {
        Player player = p_272607_.getPlayer();
        if (player != null && this.calculateHitResult(player).getType() == HitResult.Type.BLOCK) {
            player.startUsingItem(p_272607_.getHand());
        }

        return InteractionResult.CONSUME;
    }

    @Override
    public ItemUseAnimation getUseAnimation(ItemStack p_273490_) {
        return ItemUseAnimation.BRUSH;
    }

    @Override
    public int getUseDuration(ItemStack p_272765_, LivingEntity p_343510_) {
        return 200;
    }

    @Override
    public void onUseTick(Level p_273467_, LivingEntity p_273619_, ItemStack p_273316_, int p_273101_) {
        if (p_273101_ >= 0 && p_273619_ instanceof Player player) {
            HitResult hitresult = this.calculateHitResult(player);
            if (hitresult instanceof BlockHitResult blockhitresult && hitresult.getType() == HitResult.Type.BLOCK) {
                int i = this.getUseDuration(p_273316_, p_273619_) - p_273101_ + 1;
                boolean flag = i % 10 == 5;
                if (flag) {
                    BlockPos blockpos = blockhitresult.getBlockPos();
                    BlockState blockstate = p_273467_.getBlockState(blockpos);
                    HumanoidArm humanoidarm = p_273619_.getUsedItemHand() == InteractionHand.MAIN_HAND ? player.getMainArm() : player.getMainArm().getOpposite();
                    if (blockstate.shouldSpawnTerrainParticles() && blockstate.getRenderShape() != RenderShape.INVISIBLE) {
                        this.spawnDustParticles(p_273467_, blockhitresult, blockstate, p_273619_.getViewVector(0.0F), humanoidarm);
                    }

                    SoundEvent soundevent;
                    if (blockstate.getBlock() instanceof BrushableBlock brushableblock) {
                        soundevent = brushableblock.getBrushSound();
                    } else {
                        soundevent = SoundEvents.BRUSH_GENERIC;
                    }

                    p_273467_.playSound(player, blockpos, soundevent, SoundSource.BLOCKS);
                    if (p_273467_ instanceof ServerLevel serverlevel && p_273467_.getBlockEntity(blockpos) instanceof BrushableBlockEntity brushableblockentity) {
                        boolean flag1 = brushableblockentity.brush(p_273467_.getGameTime(), serverlevel, player, blockhitresult.getDirection(), p_273316_);
                        if (flag1) {
                            EquipmentSlot equipmentslot = p_273316_.equals(player.getItemBySlot(EquipmentSlot.OFFHAND))
                                ? EquipmentSlot.OFFHAND
                                : EquipmentSlot.MAINHAND;
                            p_273316_.hurtAndBreak(1, player, equipmentslot);
                        }
                    }
                }

                return;
            }

            p_273619_.releaseUsingItem();
        } else {
            p_273619_.releaseUsingItem();
        }
    }

    private HitResult calculateHitResult(Player p_311819_) {
        return ProjectileUtil.getHitResultOnViewVector(p_311819_, EntitySelector.CAN_BE_PICKED, p_311819_.blockInteractionRange());
    }

    private void spawnDustParticles(Level p_278327_, BlockHitResult p_278272_, BlockState p_278235_, Vec3 p_278337_, HumanoidArm p_285071_) {
        double d0 = 3.0;
        int i = p_285071_ == HumanoidArm.RIGHT ? 1 : -1;
        int j = p_278327_.getRandom().nextInt(7, 12);
        BlockParticleOption blockparticleoption = new BlockParticleOption(ParticleTypes.BLOCK, p_278235_);
        Direction direction = p_278272_.getDirection();
        BrushItem.DustParticlesDelta brushitem$dustparticlesdelta = BrushItem.DustParticlesDelta.fromDirection(p_278337_, direction);
        Vec3 vec3 = p_278272_.getLocation();

        for (int k = 0; k < j; k++) {
            p_278327_.addParticle(
                blockparticleoption,
                vec3.x - (double)(direction == Direction.WEST ? 1.0E-6F : 0.0F),
                vec3.y,
                vec3.z - (double)(direction == Direction.NORTH ? 1.0E-6F : 0.0F),
                brushitem$dustparticlesdelta.xd() * (double)i * 3.0 * p_278327_.getRandom().nextDouble(),
                0.0,
                brushitem$dustparticlesdelta.zd() * (double)i * 3.0 * p_278327_.getRandom().nextDouble()
            );
        }
    }

    static record DustParticlesDelta(double xd, double yd, double zd) {
        private static final double ALONG_SIDE_DELTA = 1.0;
        private static final double OUT_FROM_SIDE_DELTA = 0.1;

        public static BrushItem.DustParticlesDelta fromDirection(Vec3 p_273421_, Direction p_272987_) {
            double d0 = 0.0;

            return switch (p_272987_) {
                case DOWN, UP -> new BrushItem.DustParticlesDelta(p_273421_.z(), 0.0, -p_273421_.x());
                case NORTH -> new BrushItem.DustParticlesDelta(1.0, 0.0, -0.1);
                case SOUTH -> new BrushItem.DustParticlesDelta(-1.0, 0.0, 0.1);
                case WEST -> new BrushItem.DustParticlesDelta(-0.1, 0.0, -1.0);
                case EAST -> new BrushItem.DustParticlesDelta(0.1, 0.0, 1.0);
            };
        }
    }
}