Syncing entities without datawatcher

[shucke]

I am wondering if there is a way to sync my entities without using the datawatcher.

I dont want to use the datawatcher since it is a lot of data and packets are easier in my opinion.

So i need to sync my entities with all the players when the entity is instatiated.

so i made this simple packet:

public class PacketEntityPetData extends PacketBase{

private EntityPet pet;

private int entityID;
private int petID;

public PacketEntityPetData(){}

public PacketEntityPetData(EntityPet entityPet){
	this.pet = entityPet;
}

@Override
public void write(ByteArrayDataOutput out) {
	if(FMLCommonHandler.instance().getEffectiveSide().isClient()){
		out.writeInt(pet.entityId);
	}else{
		out.writeInt(pet.entityId);
		out.writeInt(pet.getPet().getPetID());
	}
}

@Override
public void read(ByteArrayDataInput in) throws ProtocolException {
	if(FMLCommonHandler.instance().getEffectiveSide().isClient()){
		this.entityID = in.readInt();
		this.petID = in.readInt();
	}else{
		this.entityID = in.readInt();
	}
}

@Override
public void execute(EntityPlayer player, Side side) throws ProtocolException {
	if(side.isClient()){
		this.pet = (EntityPet) player.worldObj.getEntityByID(entityID);
		this.pet.setPetBase(petID);
	}else{
		System.out.println(this.entityID);
		this.pet = (EntityPet) player.worldObj.getEntityByID(entityID);
		PacketDispatcher.sendPacketToPlayer(new PacketEntityPetData(this.pet).makePacket(), (Player) player);
	}
}
}

and the packet is send in the entityInit method:

protected void entityInit(){
	super.entityInit();
	if(this.worldObj.isRemote){
		PacketDispatcher.sendPacketToServer(new PacketEntityPetData(this).makePacket());
	}
	//this.dataWatcher.addObject(21, Integer.valueOf(1));
}

 

but i noticed that the entity ids arent the same when i send the packet.

it prints 214 on the first tick on client opposing to the server which prints 103.

so im getting a NullPointerException.

 

anyone knows how to sync properly between client and server?

 

[Draco18s]

If it's a TileEntity you can pass XYZ coordinates, then use world.getBlockTileEntity(...)

[shadowmage4513]

A:  You cannot rely upon EntityID on the client side until AFTER that entity has been fully setup.  The entity spawn packet/data will force-set that client-side entity to use the same entityID as the server-side copy of that entity -- but only AFTER it has received all of its spawn data.  E.g.  you cannot rely upon client-side entityID in the constructor for that entity.

 

(as entityInit gets called in the entity constructor, it is not yet fully setup at that point).

 

Also, as others point out, you should be sending information from server -> client in most cases.  Only rarely would you need to send client->server data from an entity -- it is usually better to handle the player interaction logic server side and use the normal server-> client update channels.

 

The proper method to setup a client-side entity is to use the IEntityAdditionalSpawnData interface to load the initial client-side entity with data.  After that, a data-watcher is probably the best built-in method to keep things synched.  It has less overhead than you seem to think -- the data-watcher is already being synched to client-- adding in a few more bits (ints) of data is small compared to the overhead of a complete packet for only sending 1/2 ints -- data watchers also only update/send data when their data has changed.

[shucke]

I thought that since the entity init was also called on the client side i just created a package to request the data from the server and send a new package back to the client.

 

and i didnt know about the IEntityAdditionalSpawnData interface

but that is exactly what i needed, thx!