Code/net/minecraft/world/entity/projectile/Arrow.java

package net.minecraft.world.entity.projectile;

import javax.annotation.Nullable;
import net.minecraft.core.component.DataComponents;
import net.minecraft.core.particles.ColorParticleOption;
import net.minecraft.core.particles.ParticleTypes;
import net.minecraft.network.syncher.EntityDataAccessor;
import net.minecraft.network.syncher.EntityDataSerializers;
import net.minecraft.network.syncher.SynchedEntityData;
import net.minecraft.world.effect.MobEffectInstance;
import net.minecraft.world.entity.Entity;
import net.minecraft.world.entity.EntityType;
import net.minecraft.world.entity.LivingEntity;
import net.minecraft.world.item.ItemStack;
import net.minecraft.world.item.Items;
import net.minecraft.world.item.alchemy.PotionContents;
import net.minecraft.world.level.Level;

public class Arrow extends AbstractArrow {
    private static final int EXPOSED_POTION_DECAY_TIME = 600;
    private static final int NO_EFFECT_COLOR = -1;
    private static final EntityDataAccessor<Integer> ID_EFFECT_COLOR = SynchedEntityData.defineId(Arrow.class, EntityDataSerializers.INT);
    private static final byte EVENT_POTION_PUFF = 0;

    public Arrow(EntityType<? extends Arrow> p_36858_, Level p_36859_) {
        super(p_36858_, p_36859_);
    }

    public Arrow(Level p_36866_, double p_312497_, double p_312591_, double p_311058_, ItemStack p_310811_, @Nullable ItemStack p_343588_) {
        super(EntityType.ARROW, p_312497_, p_312591_, p_311058_, p_36866_, p_310811_, p_343588_);
        this.updateColor();
    }

    public Arrow(Level p_36861_, LivingEntity p_310439_, ItemStack p_310691_, @Nullable ItemStack p_344310_) {
        super(EntityType.ARROW, p_310439_, p_36861_, p_310691_, p_344310_);
        this.updateColor();
    }

    private PotionContents getPotionContents() {
        return this.getPickupItemStackOrigin().getOrDefault(DataComponents.POTION_CONTENTS, PotionContents.EMPTY);
    }

    private float getPotionDurationScale() {
        return this.getPickupItemStackOrigin().getOrDefault(DataComponents.POTION_DURATION_SCALE, 1.0F);
    }

    private void setPotionContents(PotionContents p_328713_) {
        this.getPickupItemStackOrigin().set(DataComponents.POTION_CONTENTS, p_328713_);
        this.updateColor();
    }

    @Override
    protected void setPickupItemStack(ItemStack p_332340_) {
        super.setPickupItemStack(p_332340_);
        this.updateColor();
    }

    private void updateColor() {
        PotionContents potioncontents = this.getPotionContents();
        this.entityData.set(ID_EFFECT_COLOR, potioncontents.equals(PotionContents.EMPTY) ? -1 : potioncontents.getColor());
    }

    public void addEffect(MobEffectInstance p_36871_) {
        this.setPotionContents(this.getPotionContents().withEffectAdded(p_36871_));
    }

    @Override
    protected void defineSynchedData(SynchedEntityData.Builder p_331799_) {
        super.defineSynchedData(p_331799_);
        p_331799_.define(ID_EFFECT_COLOR, -1);
    }

    @Override
    public void tick() {
        super.tick();
        if (this.level().isClientSide) {
            if (this.isInGround()) {
                if (this.inGroundTime % 5 == 0) {
                    this.makeParticle(1);
                }
            } else {
                this.makeParticle(2);
            }
        } else if (this.isInGround() && this.inGroundTime != 0 && !this.getPotionContents().equals(PotionContents.EMPTY) && this.inGroundTime >= 600) {
            this.level().broadcastEntityEvent(this, (byte)0);
            this.setPickupItemStack(new ItemStack(Items.ARROW));
        }
    }

    private void makeParticle(int p_36877_) {
        int i = this.getColor();
        if (i != -1 && p_36877_ > 0) {
            for (int j = 0; j < p_36877_; j++) {
                this.level()
                    .addParticle(ColorParticleOption.create(ParticleTypes.ENTITY_EFFECT, i), this.getRandomX(0.5), this.getRandomY(), this.getRandomZ(0.5), 0.0, 0.0, 0.0);
            }
        }
    }

    public int getColor() {
        return this.entityData.get(ID_EFFECT_COLOR);
    }

    @Override
    protected void doPostHurtEffects(LivingEntity p_36873_) {
        super.doPostHurtEffects(p_36873_);
        Entity entity = this.getEffectSource();
        PotionContents potioncontents = this.getPotionContents();
        float f = this.getPotionDurationScale();
        potioncontents.forEachEffect(p_390741_ -> p_36873_.addEffect(p_390741_, entity), f);
    }

    @Override
    protected ItemStack getDefaultPickupItem() {
        return new ItemStack(Items.ARROW);
    }

    @Override
    public void handleEntityEvent(byte p_36869_) {
        if (p_36869_ == 0) {
            int i = this.getColor();
            if (i != -1) {
                float f = (i >> 16 & 0xFF) / 255.0F;
                float f1 = (i >> 8 & 0xFF) / 255.0F;
                float f2 = (i >> 0 & 0xFF) / 255.0F;

                for (int j = 0; j < 20; j++) {
                    this.level()
                        .addParticle(
                            ColorParticleOption.create(ParticleTypes.ENTITY_EFFECT, f, f1, f2),
                            this.getRandomX(0.5),
                            this.getRandomY(),
                            this.getRandomZ(0.5),
                            0.0,
                            0.0,
                            0.0
                        );
                }
            }
        } else {
            super.handleEntityEvent(p_36869_);
        }
    }
}