How to make an entity to save its property when reentering the game?

[GsE-26]

Hello! I was trying to create a mob which has two different textures: "red" and "black". It should be chosen randomly when the mob spawns and then never change. I had to find some way to save data about the variant of the mob when player go out from the game. I thought that using read/addAdditionalSaveData can help, but nothing has changed, it still doesn't remember what color each mob had. Did I something wrong? Here are methods in MyEntity class, related to the problem:

private final static EntityDataAccessor<String> DATA_VARIANT_NAME = SynchedEntityData.defineId(MyEntity.class, EntityDataSerializers.STRING);

//Entity variant is set in constructor
public MyEntity(EntityType<? extends Animal> pEntityType, Level pLevel) {
    super(pEntityType, pLevel);
    setMyEntityVariant(RandomMyEntityVariant());
}

@Override
protected void defineSynchedData() {
    super.defineSynchedData();
    this.entityData.define(DATA_VARIANT_NAME, RandomMyEntityVariant().getSerializedName());
}

public static enum MyEntityVariant implements StringRepresentable{
    RED("red"),
    BLACK("black");

    private final String name;

    private MyEntityVariant(String name){
        this.name = name;
    }

    @Override
    public String getSerializedName() {
        return name;
    }

    public static MyEntityVariant byName(String pName) {
        if (Objects.equals(pName, "black")){
            return BLACK;
        }
        else return RED;
    }
}

private MyEntityVariant RandomMyEntityVariant(){
    switch (this.random.nextIntBetweenInclusive(1,2)){
        case 1:
            return MyEntityVariant.BLACK;
        default:
            return MyEntityVariant.RED;
    }
}

public MyEntityVariant getMyEntityVariant(){
    return MyEntityVariant.byName(this.entityData.get(DATA_VARIANT_NAME));
}

public void setMyEntityVariant(MyEntityVariant variant){
    this.entityData.set(DATA_VARIANT_NAME,variant.getSerializedName());
}

@Override
public void addAdditionalSaveData(CompoundTag pCompound) {
    super.addAdditionalSaveData(pCompound);
    pCompound.putString("MyEntityVariant",this.getVariant().getSerializedName());
}

@Override
public void readAdditionalSaveData(CompoundTag pCompound) {
    super.readAdditionalSaveData(pCompound);
    this.setMyEntityVariant(MyEntityVariant.byName(pCompound.getString("MyEntityVariant")));
}

Maybe, I should call SetMyEntityVariant somewhere in another place?

[Xoroshio]

You could store your variant as a plain string, then implement IEntityAdditionalSpawnData, and write and read your string to the client there. Then just read and write your string inside read/addAdditionalSaveData

[GsE-26]

9 hours ago, Xoroshio said:

You could store your variant as a plain string, then implement IEntityAdditionalSpawnData, and write and read your string to the client there. Then just read and write your string inside read/addAdditionalSaveData

Thank you! So I mustn't to use EntityData to store the variant? Also, when implementing IEntityAdditionalSpawnData I must override two additional methods (write/readSpawnData). Should I write and read my string in two places (write/readSpawnData and read/addAdditionalSaveData)?

[Xoroshio]

no you dont need EntityData, and yes, read and write your string in the read/writeSpawn data

[GsE-26]

55 minutes ago, Xoroshio said:

no you dont need EntityData, and yes, read and write your string in the read/writeSpawn data

Something still goes wrong. I've changed my code: added new field Variant, which also is set randomly in constructor. Here are my write/readSpawnData:

@Override
public void writeSpawnData(FriendlyByteBuf friendlyByteBuf) {
    System.out.print("WRITING");
    friendlyByteBuf.writeEnum(this.getVariant());
}

@Override
public void readSpawnData(FriendlyByteBuf friendlyByteBuf) {
    System.out.print("READING");
    friendlyByteBuf.readEnum(MyEntityType.class);
}

But in my log WRITING or READING never appears. So when these methods should be called?

[Xoroshio]

I should be working, I’m not sure what’s going on. Have you registered the entity, and are you spawning it in the world?

Also, you need to do variant = friendlyByteBuff.readEnum(MyEntityType.class);

currently you are just reading the data and not doing anything with it, but that’s a minor problem compared to the methods not firing. The read and write spawn data methods are called automatically by the games client packet manager.

[Xoroshio]

Ok here is some code that I think might do the job

 

public class MyEntity extends Animal {

// 0 : black

// 1 : red
private int colorId;

public MyEntity(EntityType<? extends Animal> pEntityType, Level pLevel) {

super(pEntityType, pLevel);

colourId = pLevel.random().nextInt(0,1);

}

@Override public void addAdditionalSaveData(CompoundTag pCompound) { super.addAdditionalSaveData(pCompound); pCompound.putInt("MyEntityVariant",colourId);

}

@Override public void readAdditionalSaveData(CompoundTag pCompound) { super.readAdditionalSaveData(pCompound);

colorId = pCompound.getInt(“MyEntityVarient”);

}

public Packet<ClientGamePacketListener> getAddEntityPacket() {
      return new ClientboundAddEntityPacket(this, colourId);
   }

   public void recreateFromPacket(ClientboundAddEntityPacket packet) {
      super.recreateFromPacket(packet);
      colorId = packet.getData();
   }

}

Edited September 1, 2024 by Xoroshio