minecraft-src/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 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;
import org.jetbrains.annotations.Nullable;

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);
	/**
	 * Contains a Map of the AttributeModifiers registered by potions
	 */
	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 blendInDurationTicks;
	private int blendOutDurationTicks;
	private int blendOutAdvanceTicks;
	private Optional<SoundEvent> soundOnAdded = Optional.empty();
	private FeatureFlagSet requiredFeatures = FeatureFlags.VANILLA_SET;

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

	protected MobEffect(MobEffectCategory category, int color, ParticleOptions particle) {
		this.category = category;
		this.color = color;
		this.particleFactory = mobEffectInstance -> particle;
	}

	public int getBlendInDurationTicks() {
		return this.blendInDurationTicks;
	}

	public int getBlendOutDurationTicks() {
		return this.blendOutDurationTicks;
	}

	public int getBlendOutAdvanceTicks() {
		return this.blendOutAdvanceTicks;
	}

	public boolean applyEffectTick(ServerLevel level, LivingEntity entity, int amplifier) {
		return true;
	}

	public void applyInstantenousEffect(
		ServerLevel level, @Nullable Entity source, @Nullable Entity indirectSource, LivingEntity entity, int amplifier, double health
	) {
		this.applyEffectTick(level, entity, amplifier);
	}

	public boolean shouldApplyEffectTickThisTick(int duration, int amplifier) {
		return false;
	}

	public void onEffectStarted(LivingEntity entity, int amplifier) {
	}

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

	public void onMobRemoved(ServerLevel level, LivingEntity entity, int amplifier, Entity.RemovalReason reason) {
	}

	public void onMobHurt(ServerLevel level, LivingEntity entity, int amplifier, DamageSource damageSource, float amount) {
	}

	/**
	 * Returns {@code true} if the potion has an instant effect instead of a continuous one (e.g. Harming)
	 */
	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;
	}

	/**
	 * Returns the name of the effect.
	 */
	public String getDescriptionId() {
		return this.getOrCreateDescriptionId();
	}

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

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

	/**
	 * Returns the color of the potion liquid.
	 */
	public int getColor() {
		return this.color;
	}

	public MobEffect addAttributeModifier(Holder<Attribute> attribute, ResourceLocation id, double amount, AttributeModifier.Operation operation) {
		this.attributeModifiers.put(attribute, new MobEffect.AttributeTemplate(id, amount, operation));
		return this;
	}

	public MobEffect setBlendDuration(int blendDuration) {
		return this.setBlendDuration(blendDuration, blendDuration, blendDuration);
	}

	public MobEffect setBlendDuration(int blendInDurationTicks, int blendOutDurationTicks, int blendOutAdvanceTicks) {
		this.blendInDurationTicks = blendInDurationTicks;
		this.blendOutDurationTicks = blendOutDurationTicks;
		this.blendOutAdvanceTicks = blendOutAdvanceTicks;
		return this;
	}

	public void createModifiers(int amplifier, BiConsumer<Holder<Attribute>, AttributeModifier> output) {
		this.attributeModifiers.forEach((holder, attributeTemplate) -> output.accept(holder, attributeTemplate.create(amplifier)));
	}

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

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

	/**
	 * Get if the potion is beneficial to the player. Beneficial potions are shown on the first row of the HUD
	 */
	public boolean isBeneficial() {
		return this.category == MobEffectCategory.BENEFICIAL;
	}

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

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

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

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

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