src/game/java/net/minecraft/world/effect/MobEffect.java

package net.minecraft.world.effect;

import com.mojang.serialization.Codec;
import it.unimi.dsi.fastutil.objects.Object2ObjectOpenHashMap;
import java.util.Map;
import java.util.Optional;
import java.util.Map.Entry;
import java.util.function.BiConsumer;
import java.util.function.Function;
import javax.annotation.Nullable;
import net.minecraft.Util;
import net.minecraft.core.Holder;
import net.minecraft.core.particles.ColorParticleOption;
import net.minecraft.core.particles.ParticleOptions;
import net.minecraft.core.particles.ParticleTypes;
import net.minecraft.core.registries.BuiltInRegistries;
import net.minecraft.core.registries.Registries;
import net.minecraft.network.RegistryFriendlyByteBuf;
import net.minecraft.network.chat.Component;
import net.minecraft.network.codec.ByteBufCodecs;
import net.minecraft.network.codec.StreamCodec;
import net.minecraft.resources.ResourceLocation;
import net.minecraft.server.level.ServerLevel;
import net.minecraft.sounds.SoundEvent;
import net.minecraft.util.ARGB;
import net.minecraft.util.Mth;
import net.minecraft.world.damagesource.DamageSource;
import net.minecraft.world.entity.Entity;
import net.minecraft.world.entity.LivingEntity;
import net.minecraft.world.entity.ai.attributes.Attribute;
import net.minecraft.world.entity.ai.attributes.AttributeInstance;
import net.minecraft.world.entity.ai.attributes.AttributeMap;
import net.minecraft.world.entity.ai.attributes.AttributeModifier;
import net.minecraft.world.flag.FeatureElement;
import net.minecraft.world.flag.FeatureFlag;
import net.minecraft.world.flag.FeatureFlagSet;
import net.minecraft.world.flag.FeatureFlags;

public class MobEffect implements FeatureElement {
    public static final Codec<Holder<MobEffect>> CODEC = BuiltInRegistries.MOB_EFFECT.holderByNameCodec();
    public static final StreamCodec<RegistryFriendlyByteBuf, Holder<MobEffect>> STREAM_CODEC = ByteBufCodecs.holderRegistry(Registries.MOB_EFFECT);
    private static final int AMBIENT_ALPHA = Mth.floor(38.25F);
    private final Map<Holder<Attribute>, MobEffect.AttributeTemplate> attributeModifiers = new Object2ObjectOpenHashMap<>();
    private final MobEffectCategory category;
    private final int color;
    private final Function<MobEffectInstance, ParticleOptions> particleFactory;
    @Nullable
    private String descriptionId;
    private int blendDurationTicks;
    private Optional<SoundEvent> soundOnAdded = Optional.empty();
    private FeatureFlagSet requiredFeatures = FeatureFlags.VANILLA_SET;

    protected MobEffect(MobEffectCategory p_19451_, int p_19452_) {
        this.category = p_19451_;
        this.color = p_19452_;
        this.particleFactory = p_358853_ -> {
            int i = p_358853_.isAmbient() ? AMBIENT_ALPHA : 255;
            return ColorParticleOption.create(ParticleTypes.ENTITY_EFFECT, ARGB.color(i, p_19452_));
        };
    }

    protected MobEffect(MobEffectCategory p_335432_, int p_334901_, ParticleOptions p_331136_) {
        this.category = p_335432_;
        this.color = p_334901_;
        this.particleFactory = p_326745_ -> p_331136_;
    }

    public int getBlendDurationTicks() {
        return this.blendDurationTicks;
    }

    public boolean applyEffectTick(ServerLevel p_361900_, LivingEntity p_333541_, int p_333570_) {
        return true;
    }

    public void applyInstantenousEffect(ServerLevel p_369379_, @Nullable Entity p_19462_, @Nullable Entity p_19463_, LivingEntity p_19464_, int p_19465_, double p_19466_) {
        this.applyEffectTick(p_369379_, p_19464_, p_19465_);
    }

    public boolean shouldApplyEffectTickThisTick(int p_297908_, int p_301085_) {
        return false;
    }

    public void onEffectStarted(LivingEntity p_299085_, int p_297449_) {
    }

    public void onEffectAdded(LivingEntity p_335100_, int p_336309_) {
        this.soundOnAdded
            .ifPresent(
                p_374927_ -> p_335100_.level()
                        .playSound(null, p_335100_.getX(), p_335100_.getY(), p_335100_.getZ(), p_374927_, p_335100_.getSoundSource(), 1.0F, 1.0F)
            );
    }

    public void onMobRemoved(ServerLevel p_368376_, LivingEntity p_335815_, int p_328980_, Entity.RemovalReason p_328413_) {
    }

    public void onMobHurt(ServerLevel p_367917_, LivingEntity p_19467_, int p_19468_, DamageSource p_334111_, float p_330556_) {
    }

    public boolean isInstantenous() {
        return false;
    }

    protected String getOrCreateDescriptionId() {
        if (this.descriptionId == null) {
            this.descriptionId = Util.makeDescriptionId("effect", BuiltInRegistries.MOB_EFFECT.getKey(this));
        }

        return this.descriptionId;
    }

    public String getDescriptionId() {
        return this.getOrCreateDescriptionId();
    }

    public Component getDisplayName() {
        return Component.translatable(this.getDescriptionId());
    }

    public MobEffectCategory getCategory() {
        return this.category;
    }

    public int getColor() {
        return this.color;
    }

    public MobEffect addAttributeModifier(Holder<Attribute> p_332101_, ResourceLocation p_342976_, double p_19475_, AttributeModifier.Operation p_19476_) {
        this.attributeModifiers.put(p_332101_, new MobEffect.AttributeTemplate(p_342976_, p_19475_, p_19476_));
        return this;
    }

    public MobEffect setBlendDuration(int p_328727_) {
        this.blendDurationTicks = p_328727_;
        return this;
    }

    public void createModifiers(int p_334564_, BiConsumer<Holder<Attribute>, AttributeModifier> p_333602_) {
        this.attributeModifiers.forEach((p_341255_, p_341256_) -> p_333602_.accept((Holder<Attribute>)p_341255_, p_341256_.create(p_334564_)));
    }

    public void removeAttributeModifiers(AttributeMap p_19470_) {
        for (Entry<Holder<Attribute>, MobEffect.AttributeTemplate> entry : this.attributeModifiers.entrySet()) {
            AttributeInstance attributeinstance = p_19470_.getInstance(entry.getKey());
            if (attributeinstance != null) {
                attributeinstance.removeModifier(entry.getValue().id());
            }
        }
    }

    public void addAttributeModifiers(AttributeMap p_19479_, int p_19480_) {
        for (Entry<Holder<Attribute>, MobEffect.AttributeTemplate> entry : this.attributeModifiers.entrySet()) {
            AttributeInstance attributeinstance = p_19479_.getInstance(entry.getKey());
            if (attributeinstance != null) {
                attributeinstance.removeModifier(entry.getValue().id());
                attributeinstance.addPermanentModifier(entry.getValue().create(p_19480_));
            }
        }
    }

    public boolean isBeneficial() {
        return this.category == MobEffectCategory.BENEFICIAL;
    }

    public ParticleOptions createParticleOptions(MobEffectInstance p_332465_) {
        return this.particleFactory.apply(p_332465_);
    }

    public MobEffect withSoundOnAdded(SoundEvent p_329951_) {
        this.soundOnAdded = Optional.of(p_329951_);
        return this;
    }

    public MobEffect requiredFeatures(FeatureFlag... p_329270_) {
        this.requiredFeatures = FeatureFlags.REGISTRY.subset(p_329270_);
        return this;
    }

    @Override
    public FeatureFlagSet requiredFeatures() {
        return this.requiredFeatures;
    }

    static record AttributeTemplate(ResourceLocation id, double amount, AttributeModifier.Operation operation) {
        public AttributeModifier create(int p_332230_) {
            return new AttributeModifier(this.id, this.amount * (double)(p_332230_ + 1), this.operation);
        }
    }
}