Code/net/minecraft/world/entity/AgeableMob.java

package net.minecraft.world.entity;

import com.google.common.annotations.VisibleForTesting;
import javax.annotation.Nullable;
import net.minecraft.core.particles.ParticleTypes;
import net.minecraft.nbt.CompoundTag;
import net.minecraft.network.syncher.EntityDataAccessor;
import net.minecraft.network.syncher.EntityDataSerializers;
import net.minecraft.network.syncher.SynchedEntityData;
import net.minecraft.server.level.ServerLevel;
import net.minecraft.world.DifficultyInstance;
import net.minecraft.world.entity.vehicle.AbstractBoat;
import net.minecraft.world.level.Level;
import net.minecraft.world.level.ServerLevelAccessor;

public abstract class AgeableMob extends PathfinderMob {
    private static final EntityDataAccessor<Boolean> DATA_BABY_ID = SynchedEntityData.defineId(AgeableMob.class, EntityDataSerializers.BOOLEAN);
    public static final int BABY_START_AGE = -24000;
    private static final int FORCED_AGE_PARTICLE_TICKS = 40;
    protected static final int DEFAULT_AGE = 0;
    protected static final int DEFAULT_FORCED_AGE = 0;
    protected int age = 0;
    protected int forcedAge = 0;
    protected int forcedAgeTimer;

    protected AgeableMob(EntityType<? extends AgeableMob> p_146738_, Level p_146739_) {
        super(p_146738_, p_146739_);
    }

    @Override
    public SpawnGroupData finalizeSpawn(ServerLevelAccessor p_146746_, DifficultyInstance p_146747_, EntitySpawnReason p_366700_, @Nullable SpawnGroupData p_146749_) {
        if (p_146749_ == null) {
            p_146749_ = new AgeableMob.AgeableMobGroupData(true);
        }

        AgeableMob.AgeableMobGroupData ageablemob$ageablemobgroupdata = (AgeableMob.AgeableMobGroupData)p_146749_;
        if (ageablemob$ageablemobgroupdata.isShouldSpawnBaby()
            && ageablemob$ageablemobgroupdata.getGroupSize() > 0
            && p_146746_.getRandom().nextFloat() <= ageablemob$ageablemobgroupdata.getBabySpawnChance()) {
            this.setAge(-24000);
        }

        ageablemob$ageablemobgroupdata.increaseGroupSizeByOne();
        return super.finalizeSpawn(p_146746_, p_146747_, p_366700_, p_146749_);
    }

    @Nullable
    public abstract AgeableMob getBreedOffspring(ServerLevel p_146743_, AgeableMob p_146744_);

    @Override
    protected void defineSynchedData(SynchedEntityData.Builder p_333447_) {
        super.defineSynchedData(p_333447_);
        p_333447_.define(DATA_BABY_ID, false);
    }

    public boolean canBreed() {
        return false;
    }

    public int getAge() {
        if (this.level().isClientSide) {
            return this.entityData.get(DATA_BABY_ID) ? -1 : 1;
        } else {
            return this.age;
        }
    }

    public void ageUp(int p_146741_, boolean p_146742_) {
        int i = this.getAge();
        i += p_146741_ * 20;
        if (i > 0) {
            i = 0;
        }

        int j = i - i;
        this.setAge(i);
        if (p_146742_) {
            this.forcedAge += j;
            if (this.forcedAgeTimer == 0) {
                this.forcedAgeTimer = 40;
            }
        }

        if (this.getAge() == 0) {
            this.setAge(this.forcedAge);
        }
    }

    public void ageUp(int p_146759_) {
        this.ageUp(p_146759_, false);
    }

    public void setAge(int p_146763_) {
        int i = this.getAge();
        this.age = p_146763_;
        if (i < 0 && p_146763_ >= 0 || i >= 0 && p_146763_ < 0) {
            this.entityData.set(DATA_BABY_ID, p_146763_ < 0);
            this.ageBoundaryReached();
        }
    }

    @Override
    public void addAdditionalSaveData(CompoundTag p_146761_) {
        super.addAdditionalSaveData(p_146761_);
        p_146761_.putInt("Age", this.getAge());
        p_146761_.putInt("ForcedAge", this.forcedAge);
    }

    @Override
    public void readAdditionalSaveData(CompoundTag p_146752_) {
        super.readAdditionalSaveData(p_146752_);
        this.setAge(p_146752_.getIntOr("Age", 0));
        this.forcedAge = p_146752_.getIntOr("ForcedAge", 0);
    }

    @Override
    public void onSyncedDataUpdated(EntityDataAccessor<?> p_146754_) {
        if (DATA_BABY_ID.equals(p_146754_)) {
            this.refreshDimensions();
        }

        super.onSyncedDataUpdated(p_146754_);
    }

    @Override
    public void aiStep() {
        super.aiStep();
        if (this.level().isClientSide) {
            if (this.forcedAgeTimer > 0) {
                if (this.forcedAgeTimer % 4 == 0) {
                    this.level().addParticle(ParticleTypes.HAPPY_VILLAGER, this.getRandomX(1.0), this.getRandomY() + 0.5, this.getRandomZ(1.0), 0.0, 0.0, 0.0);
                }

                this.forcedAgeTimer--;
            }
        } else if (this.isAlive()) {
            int i = this.getAge();
            if (i < 0) {
                this.setAge(++i);
            } else if (i > 0) {
                this.setAge(--i);
            }
        }
    }

    protected void ageBoundaryReached() {
        if (!this.isBaby() && this.isPassenger() && this.getVehicle() instanceof AbstractBoat abstractboat && !abstractboat.hasEnoughSpaceFor(this)) {
            this.stopRiding();
        }
    }

    @Override
    public boolean isBaby() {
        return this.getAge() < 0;
    }

    @Override
    public void setBaby(boolean p_146756_) {
        this.setAge(p_146756_ ? -24000 : 0);
    }

    public static int getSpeedUpSecondsWhenFeeding(int p_216968_) {
        return (int)(p_216968_ / 20 * 0.1F);
    }

    @VisibleForTesting
    public int getForcedAge() {
        return this.forcedAge;
    }

    @VisibleForTesting
    public int getForcedAgeTimer() {
        return this.forcedAgeTimer;
    }

    public static class AgeableMobGroupData implements SpawnGroupData {
        private int groupSize;
        private final boolean shouldSpawnBaby;
        private final float babySpawnChance;

        public AgeableMobGroupData(boolean p_146775_, float p_146776_) {
            this.shouldSpawnBaby = p_146775_;
            this.babySpawnChance = p_146776_;
        }

        public AgeableMobGroupData(boolean p_146773_) {
            this(p_146773_, 0.05F);
        }

        public AgeableMobGroupData(float p_146771_) {
            this(true, p_146771_);
        }

        public int getGroupSize() {
            return this.groupSize;
        }

        public void increaseGroupSizeByOne() {
            this.groupSize++;
        }

        public boolean isShouldSpawnBaby() {
            return this.shouldSpawnBaby;
        }

        public float getBabySpawnChance() {
            return this.babySpawnChance;
        }
    }
}