[1.8]PlayerEvent.StartTracking problems

[FLUFFY2]

Hi guys,

 

I have a problem with the tracking event, where i send a packet to the client and when getting the other player from its ID inside the packet, it returns null for some reason.

I guess the tracking starts before the client gets to know the other client.

 

Here is how i send the packet:

@SubscribeEvent
public void StartTracking(PlayerEvent.StartTracking event){
	if(event.target instanceof EntityPlayer){
		EntityPlayer target = (EntityPlayer)event.target;
		if(!event.entityPlayer.worldObj.isRemote){
			ExtendedPlayerPropertiesHandler props = ExtendedPlayerPropertiesHandler.get(target);
			AmnesiaLights.snw.sendTo(new HotbarLanternMessageHandler(target, props.hotbarLantern), (EntityPlayerMP)event.entityPlayer);
		}
	}
}

 

Here is my packet:

package com.fluffy2.amnesialights.pakets;

import io.netty.buffer.ByteBuf;
import net.minecraft.client.Minecraft;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.world.WorldServer;
import net.minecraftforge.fml.common.FMLCommonHandler;
import net.minecraftforge.fml.common.network.simpleimpl.IMessage;
import net.minecraftforge.fml.common.network.simpleimpl.IMessageHandler;
import net.minecraftforge.fml.common.network.simpleimpl.MessageContext;
import net.minecraftforge.fml.relauncher.Side;

import com.fluffy2.amnesialights.AmnesiaLights;
import com.fluffy2.amnesialights.handler.ExtendedPlayerPropertiesHandler;

public class HotbarLanternMessageHandler implements IMessage, IMessageHandler<HotbarLanternMessageHandler, IMessage> { 

private int hotbarLantern;
private int playerID;

public HotbarLanternMessageHandler(){
}

public HotbarLanternMessageHandler(EntityPlayer player, int hotbarLantern){
	this.hotbarLantern = hotbarLantern;
	this.playerID = player.getEntityId();
}

@Override
public void toBytes(ByteBuf buf) {
	buf.writeInt(hotbarLantern);
	buf.writeInt(playerID);
}

@Override
public void fromBytes(ByteBuf buf) { 
	this.hotbarLantern = buf.readInt();
	this.playerID = buf.readInt();
}

@Override
public IMessage onMessage(final HotbarLanternMessageHandler message, final MessageContext ctx){
	if(FMLCommonHandler.instance().getEffectiveSide() == Side.CLIENT){
		EntityPlayer player = (EntityPlayer)Minecraft.getMinecraft().theWorld.getEntityByID(message.playerID);
		ExtendedPlayerPropertiesHandler.get(player).hotbarLantern = message.hotbarLantern;
	}else{
		EntityPlayer player = ctx.getServerHandler().playerEntity;
		ExtendedPlayerPropertiesHandler.get(player).hotbarLantern = message.hotbarLantern;
		((WorldServer)player.worldObj).getEntityTracker().sendToAllTrackingEntity(player, AmnesiaLights.snw.getPacketFrom(new HotbarLanternMessageHandler(player, message.hotbarLantern)));
	}
	return null;
}
}

 

So the problem in the packet is this line:

EntityPlayer player = (EntityPlayer)Minecraft.getMinecraft().theWorld.getEntityByID(message.playerID);

 

It returns null!

So my guess is, when the player connects to the server, the tracing starts, and the server sync the clients, but the packet is sent before the sync and the client cant find the other player by its entity ID.

 

Thanks for helping!

[diesieben07]

First: Read the "Warning" section here. This will fix your problem.

 

Then: Do not use getEffectiveSide. In fact checking the side in the packet handler at all is pointless, since, well, you are the one sending the packet and you know which side you send it to. And the server-side version is thereby not needed, since you should never send this packet to the server. Ever.

Also, checking world.isRemote in the tracking event is also pointless, the event only fires on the server.

[FLUFFY2]

I'm checking the side, because the packet is send to the server to set values and the packet itself send it back to the client. Its like a response packet, you need side checking, because if a server packet send a response back to the client it will also tries to run the server code and evenutally crash.

I'm just not using the return feature, instead i send the packet diferently.

 

I need side checking, but that part dont has to do anything with the current porblem.

But if you dont belive me you can always set up a packet, register it on both side, and make it send to the server that return a responce to the client. You will see you need side checking.

 

I read the "Warning" thing now, let see if it fixes it.

 

Thanks!

 

[FLUFFY2]

Ahahahah, indeed, it fixed the problem!

IThreadListener threadlistener = Minecraft.getMinecraft();
threadlistener.addScheduledTask(new Runnable(){
public void run(){
	//Message to run
}
});

 

So, i need to ask you, do i have to implement thread safety to all the packets, or its not recommended.

How can i see, if a packet needs thread safety?

The network thread cant access some game object, now what are these objects?

 

Thanks diesieben!

[diesieben07]

I'm checking the side, because the packet is send to the server to set values and the packet itself send it back to the client. Its like a response packet, you need side checking, because if a server packet send a response back to the client it will also tries to run the server code and evenutally crash.

I'm just not using the return feature, instead i send the packet diferently.

That is a bad idea. The client should NOT have the ability to just set the value for any player. Your packet does that. This is a big security hole.

The network thread cant access some game object, now what are these objects?

Unless you know what you are doing, do everything on the main thread (i.e. using addScheduledTask).

[FLUFFY2]

That is a bad idea. The client should NOT have the ability to just set the value for any player. Your packet does that. This is a big security hole.

 

I didn't get you. Than whats the purpose of the responce in the packets?

 

.registerMessage(TestMessageHandler.class, TestMessageHandler.class, 3, Side.CLIENT);
.registerMessage(TestMessageHandler.class, TestMessageHandler.class, 4, Side.SERVER);

 

.sendToServer(new TestMessageHandler(data));

 

public IMessage onMessage(final HotbarLanternMessageHandler message, final MessageContext ctx){
       if(FMLCommonHandler.instance().getEffectiveSide() == Side.CLIENT){

       }else{

       }
}

[diesieben07]

HotbarLanternMessageHandler (another thing btw, don't implement IMessage and IMessageHandler on the same class) should not be used for the client -> server packet then, because the playerID is not needed there at all.

[FLUFFY2]

Yeah, thats true, but i need to carry the data over.

 

What i do is:

On the client i check if a player has an item in a specific inventory slot, and set the Extended Player data.

I send that data to the server, set the Exteded Player data there as well, and send the data to all other tracking players. I need to carry the ID, for the client.

 

You might ask then:

WTF? Why not just check the inventory on the server, set the Extended Player on the server, and send to all tracking player(and to myself).

Answer is simple!

 

In the PlayerTickEvent, event.player means all player on the server. it lists all player.

So it causes confusion in the packet, and the data changes wierdly, sometimes even not.

 

That means, i need to use Minecraft.getMinecraft().thePlayer to get myself.

Since i cant send packet from client to client, i need to do client to server to clients.

 

So yeah, i didn't find any easier method.

[FLUFFY2]

Forgot to say:

Im not letting client to change other client data.

I just make so my client actually reads the other clients correct data.

[diesieben07]

In the PlayerTickEvent, event.player means all player on the server. it lists all player.

So it causes confusion in the packet, and the data changes wierdly, sometimes even not.

Then you are doing it wrong.

Detecting this on the server is the only proper way.

[FLUFFY2]

I might rethink the whole thing, i dont know, im too lazy!

Thank you anyways diesieben, you rock!