Code/net/minecraft/world/entity/monster/Spider.java

package net.minecraft.world.entity.monster;

import javax.annotation.Nullable;
import net.minecraft.core.BlockPos;
import net.minecraft.core.Holder;
import net.minecraft.network.syncher.EntityDataAccessor;
import net.minecraft.network.syncher.EntityDataSerializers;
import net.minecraft.network.syncher.SynchedEntityData;
import net.minecraft.sounds.SoundEvent;
import net.minecraft.sounds.SoundEvents;
import net.minecraft.util.RandomSource;
import net.minecraft.world.Difficulty;
import net.minecraft.world.DifficultyInstance;
import net.minecraft.world.damagesource.DamageSource;
import net.minecraft.world.effect.MobEffect;
import net.minecraft.world.effect.MobEffectInstance;
import net.minecraft.world.effect.MobEffects;
import net.minecraft.world.entity.Entity;
import net.minecraft.world.entity.EntitySpawnReason;
import net.minecraft.world.entity.EntityType;
import net.minecraft.world.entity.LivingEntity;
import net.minecraft.world.entity.SpawnGroupData;
import net.minecraft.world.entity.ai.attributes.AttributeSupplier;
import net.minecraft.world.entity.ai.attributes.Attributes;
import net.minecraft.world.entity.ai.goal.AvoidEntityGoal;
import net.minecraft.world.entity.ai.goal.FloatGoal;
import net.minecraft.world.entity.ai.goal.LeapAtTargetGoal;
import net.minecraft.world.entity.ai.goal.LookAtPlayerGoal;
import net.minecraft.world.entity.ai.goal.MeleeAttackGoal;
import net.minecraft.world.entity.ai.goal.RandomLookAroundGoal;
import net.minecraft.world.entity.ai.goal.WaterAvoidingRandomStrollGoal;
import net.minecraft.world.entity.ai.goal.target.HurtByTargetGoal;
import net.minecraft.world.entity.ai.goal.target.NearestAttackableTargetGoal;
import net.minecraft.world.entity.ai.navigation.PathNavigation;
import net.minecraft.world.entity.ai.navigation.WallClimberNavigation;
import net.minecraft.world.entity.animal.IronGolem;
import net.minecraft.world.entity.animal.armadillo.Armadillo;
import net.minecraft.world.entity.player.Player;
import net.minecraft.world.level.Level;
import net.minecraft.world.level.ServerLevelAccessor;
import net.minecraft.world.level.block.Blocks;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraft.world.phys.Vec3;

public class Spider extends Monster {
    private static final EntityDataAccessor<Byte> DATA_FLAGS_ID = SynchedEntityData.defineId(Spider.class, EntityDataSerializers.BYTE);
    private static final float SPIDER_SPECIAL_EFFECT_CHANCE = 0.1F;

    public Spider(EntityType<? extends Spider> p_33786_, Level p_33787_) {
        super(p_33786_, p_33787_);
    }

    @Override
    protected void registerGoals() {
        this.goalSelector.addGoal(1, new FloatGoal(this));
        this.goalSelector.addGoal(2, new AvoidEntityGoal<>(this, Armadillo.class, 6.0F, 1.0, 1.2, p_328323_ -> !((Armadillo)p_328323_).isScared()));
        this.goalSelector.addGoal(3, new LeapAtTargetGoal(this, 0.4F));
        this.goalSelector.addGoal(4, new Spider.SpiderAttackGoal(this));
        this.goalSelector.addGoal(5, new WaterAvoidingRandomStrollGoal(this, 0.8));
        this.goalSelector.addGoal(6, new LookAtPlayerGoal(this, Player.class, 8.0F));
        this.goalSelector.addGoal(6, new RandomLookAroundGoal(this));
        this.targetSelector.addGoal(1, new HurtByTargetGoal(this));
        this.targetSelector.addGoal(2, new Spider.SpiderTargetGoal<>(this, Player.class));
        this.targetSelector.addGoal(3, new Spider.SpiderTargetGoal<>(this, IronGolem.class));
    }

    @Override
    protected PathNavigation createNavigation(Level p_33802_) {
        return new WallClimberNavigation(this, p_33802_);
    }

    @Override
    protected void defineSynchedData(SynchedEntityData.Builder p_334759_) {
        super.defineSynchedData(p_334759_);
        p_334759_.define(DATA_FLAGS_ID, (byte)0);
    }

    @Override
    public void tick() {
        super.tick();
        if (!this.level().isClientSide) {
            this.setClimbing(this.horizontalCollision);
        }
    }

    public static AttributeSupplier.Builder createAttributes() {
        return Monster.createMonsterAttributes().add(Attributes.MAX_HEALTH, 16.0).add(Attributes.MOVEMENT_SPEED, 0.3F);
    }

    @Override
    protected SoundEvent getAmbientSound() {
        return SoundEvents.SPIDER_AMBIENT;
    }

    @Override
    protected SoundEvent getHurtSound(DamageSource p_33814_) {
        return SoundEvents.SPIDER_HURT;
    }

    @Override
    protected SoundEvent getDeathSound() {
        return SoundEvents.SPIDER_DEATH;
    }

    @Override
    protected void playStepSound(BlockPos p_33804_, BlockState p_33805_) {
        this.playSound(SoundEvents.SPIDER_STEP, 0.15F, 1.0F);
    }

    @Override
    public boolean onClimbable() {
        return this.isClimbing();
    }

    @Override
    public void makeStuckInBlock(BlockState p_33796_, Vec3 p_33797_) {
        if (!p_33796_.is(Blocks.COBWEB)) {
            super.makeStuckInBlock(p_33796_, p_33797_);
        }
    }

    @Override
    public boolean canBeAffected(MobEffectInstance p_33809_) {
        return p_33809_.is(MobEffects.POISON) ? false : super.canBeAffected(p_33809_);
    }

    public boolean isClimbing() {
        return (this.entityData.get(DATA_FLAGS_ID) & 1) != 0;
    }

    public void setClimbing(boolean p_33820_) {
        byte b0 = this.entityData.get(DATA_FLAGS_ID);
        if (p_33820_) {
            b0 = (byte)(b0 | 1);
        } else {
            b0 = (byte)(b0 & -2);
        }

        this.entityData.set(DATA_FLAGS_ID, b0);
    }

    @Nullable
    @Override
    public SpawnGroupData finalizeSpawn(ServerLevelAccessor p_33790_, DifficultyInstance p_33791_, EntitySpawnReason p_368176_, @Nullable SpawnGroupData p_33793_) {
        p_33793_ = super.finalizeSpawn(p_33790_, p_33791_, p_368176_, p_33793_);
        RandomSource randomsource = p_33790_.getRandom();
        if (randomsource.nextInt(100) == 0) {
            Skeleton skeleton = EntityType.SKELETON.create(this.level(), EntitySpawnReason.JOCKEY);
            if (skeleton != null) {
                skeleton.snapTo(this.getX(), this.getY(), this.getZ(), this.getYRot(), 0.0F);
                skeleton.finalizeSpawn(p_33790_, p_33791_, p_368176_, null);
                skeleton.startRiding(this);
            }
        }

        if (p_33793_ == null) {
            p_33793_ = new Spider.SpiderEffectsGroupData();
            if (p_33790_.getDifficulty() == Difficulty.HARD && randomsource.nextFloat() < 0.1F * p_33791_.getSpecialMultiplier()) {
                ((Spider.SpiderEffectsGroupData)p_33793_).setRandomEffect(randomsource);
            }
        }

        if (p_33793_ instanceof Spider.SpiderEffectsGroupData spider$spidereffectsgroupdata) {
            Holder<MobEffect> holder = spider$spidereffectsgroupdata.effect;
            if (holder != null) {
                this.addEffect(new MobEffectInstance(holder, -1));
            }
        }

        return p_33793_;
    }

    @Override
    public Vec3 getVehicleAttachmentPoint(Entity p_333349_) {
        return p_333349_.getBbWidth() <= this.getBbWidth() ? new Vec3(0.0, 0.3125 * this.getScale(), 0.0) : super.getVehicleAttachmentPoint(p_333349_);
    }

    static class SpiderAttackGoal extends MeleeAttackGoal {
        public SpiderAttackGoal(Spider p_33822_) {
            super(p_33822_, 1.0, true);
        }

        @Override
        public boolean canUse() {
            return super.canUse() && !this.mob.isVehicle();
        }

        @Override
        public boolean canContinueToUse() {
            float f = this.mob.getLightLevelDependentMagicValue();
            if (f >= 0.5F && this.mob.getRandom().nextInt(100) == 0) {
                this.mob.setTarget(null);
                return false;
            } else {
                return super.canContinueToUse();
            }
        }
    }

    public static class SpiderEffectsGroupData implements SpawnGroupData {
        @Nullable
        public Holder<MobEffect> effect;

        public void setRandomEffect(RandomSource p_219119_) {
            int i = p_219119_.nextInt(5);
            if (i <= 1) {
                this.effect = MobEffects.SPEED;
            } else if (i <= 2) {
                this.effect = MobEffects.STRENGTH;
            } else if (i <= 3) {
                this.effect = MobEffects.REGENERATION;
            } else if (i <= 4) {
                this.effect = MobEffects.INVISIBILITY;
            }
        }
    }

    static class SpiderTargetGoal<T extends LivingEntity> extends NearestAttackableTargetGoal<T> {
        public SpiderTargetGoal(Spider p_33832_, Class<T> p_33833_) {
            super(p_33832_, p_33833_, true);
        }

        @Override
        public boolean canUse() {
            float f = this.mob.getLightLevelDependentMagicValue();
            return f >= 0.5F ? false : super.canUse();
        }
    }
}