How do i create custom packets?

[Seynox]

Hello!

I'm trying to make a packet when the player press his jump keybind.

I have a custom item that allow you to double jump when equipped in a Bauble Slot (Belt slot).

 

Everything seems to work, i only need to know when the player press space when he's not touching the ground.

I already saw the Forge Doc about SimpleImpl, but i don't really get it.. Do i need 3 class? PacketHandler, MyMessage and MyMessageHandler? (I guess i can rename the Messages classes)

 

Here's the item im making :

Spoiler

boolean usedDoubleJump = false;
	public void onWornTick(ItemStack itemstack, EntityLivingBase player) {
		World world = player.world;
		
		if(!player.onGround) {
			if(/*player press space &&*/!usedDoubleJump) {
				usedDoubleJump = true;
				player.motionY = 0.42D;
				player.fallDistance = 0;
			}
			
			
		} else if(usedDoubleJump) {usedDoubleJump = false;}
	}

 

Can you guys give me examples?

[Cadiboo]

What version

[Seynox]

Just now, Cadiboo said:

What version

1.12.2

[Seynox]

I pretty much copied Botania's PacketHandler and PacketJump that looks pretty strange but i think that's pretty much what i want, and it's not doing anything so it might be outdated, or i did something wrong

[Seynox]

Anyone?

[Seynox]

Is this outdated? https://gist.github.com/CatDany/4a3df7fcb3c8270cf70b

If i get it, after doing this i just have to put the condition before sending the packet right? Like in useExemple

[Seynox]

Okay so here's what i did. Every println are showing up in the console, which mean everything is working, but the player.motionY = 0.42D; (Inside PacketJump) is not happening, and i don't have any errors. I think it might be a side problem, but i don't see how i can fix it

 

ClientProxy :

Spoiler

@Override
    public void preInit(FMLPreInitializationEvent event) {

        MinecraftForge.EVENT_BUS.register(new KeyPressHandler());

}

 

 

KeyPressHandler :

Spoiler

@SideOnly(Side.CLIENT)
public class KeyPressHandler {
    
    @SubscribeEvent
    public void onKeyPress(InputEvent.KeyInputEvent event) {
        
        EntityPlayerSP player = Minecraft.getMinecraft().player;
        World world = player.world;

        if (Minecraft.getMinecraft().gameSettings.keyBindJump.isPressed() && !player.onGround) {
            IMessage jumpmsg = new PacketJump.JumpMessage(player.getEntityId());
            PacketHandler.INSTANCE.sendToServer(jumpmsg);
            System.out.println("Jump Packet sent. Player : " + player);
            return;
        }
    }

}

 

 

PacketHandler :

Spoiler

public class PacketHandler {
	
	public static final SimpleNetworkWrapper INSTANCE = NetworkRegistry.INSTANCE.newSimpleChannel(Reference.MOD_ID.toLowerCase());
	
	public static void init() {
		registerMessage(PacketJump.class, PacketJump.JumpMessage.class);
	}
	
	private static int nextPacketId = 0;
	  
	  private static void registerMessage(Class packet, Class message)
	  {
	    INSTANCE.registerMessage(packet, message, nextPacketId, Side.CLIENT);
	    INSTANCE.registerMessage(packet, message, nextPacketId, Side.SERVER);
	    nextPacketId++;
	}

}

 

 

PacketJump :

Spoiler

public class PacketJump implements IMessageHandler<PacketJump.JumpMessage, IMessage>
{
	  @Override
		public IMessage onMessage(JumpMessage message, MessageContext ctx)
		{
		  EntityPlayer playerID = (ctx.side.isClient() ? Minecraft.getMinecraft().player : ctx.getServerHandler().player);
		  EntityPlayer player = (EntityPlayer)playerID.world.getEntityByID(message.playerid);
		  
		  boolean usedDoubleJump = false;
		  
		  ItemStack belt = BaublesApi.getBaublesHandler(player).getStackInSlot(3);
		  if(!belt.isEmpty() && belt.getItem() instanceof CloudInJar && !usedDoubleJump) {
			    usedDoubleJump = true;
				player.motionY = 0.42D;
				player.fallDistance = 0;
				System.out.println("Added motionY to " + player);
		  }
		  
		return null;
		}
	  
	  public static class JumpMessage implements IMessage
	  {
	    int playerid;
	    
	    public JumpMessage() {}
	    
	    public JumpMessage(int playerid)
	    {
	      this.playerid = playerid;
	    }
	    
	    @Override
	    public void fromBytes(ByteBuf buf)
	    {
	      this.playerid = ByteBufUtils.readVarInt(buf, 4);
	    }
	    
	    @Override
	    public void toBytes(ByteBuf buf)
	    {
	    	ByteBufUtils.writeVarInt(buf, playerid, 4);
	    }
	}
	  
	  
}

 

 

The console output when i press space while in the air :

Spoiler

[15:23:06] [main/INFO] [STDOUT]: [com.seynox.seynoxstuffmod.util.handlers.KeyPressHandler:onKeyPress:28]: Jump Packet sent. Player : EntityPlayerSP['Player644'/79, l='MpServer', x=601.12, y=83.25, z=648.43]
[15:23:06] [Netty Server IO #1/INFO] [STDOUT]: [com.seynox.seynoxstuffmod.network.PacketJump:onMessage:33]: Added motionY to EntityPlayerMP['Player644'/79, l='border', x=601.12, y=83.25, z=648.43]

 

[V0idWa1k3r]

I know it seems counter-intuitive but player motion must be changed on the client, the server doesn't actually control it.

[Cadiboo]

You can get rid of your client proxy and use @EventBusSubscriber(modid = YourMod.MODID, value = Side.CLIENT) with static methods in your class

[Seynox]

6 hours ago, V0idWa1k3r said:

I know it seems counter-intuitive but player motion must be changed on the client, the server doesn't actually control it.

How can i make the client execute player.motionY? world.isRemote isnt working here

[Seynox]

Nevermind, i just added the motionY in the KeyPressHandler! Thanks a lot!

[Seynox]

I just tried the mod on server, and it's crashing about the EntityPlayerSP

Spoiler

Caused by: java.lang.NoClassDefFoundError: net/minecraft/client/entity/EntityPlayerSP
	at java.lang.Class.getDeclaredConstructors0(Native Method) ~[?:1.8.0_211]
	at java.lang.Class.privateGetDeclaredConstructors(Unknown Source) ~[?:1.8.0_211]
	at java.lang.Class.getConstructor0(Unknown Source) ~[?:1.8.0_211]
	at java.lang.Class.newInstance(Unknown Source) ~[?:1.8.0_211]
	at net.minecraftforge.fml.common.network.simpleimpl.SimpleNetworkWrapper.instantiate(SimpleNetworkWrapper.java:166) ~[SimpleNetworkWrapper.class:?]
	at net.minecraftforge.fml.common.network.simpleimpl.SimpleNetworkWrapper.registerMessage(SimpleNetworkWrapper.java:159) ~[SimpleNetworkWrapper.class:?]
	at com.seynox.adventum.network.PacketHandler.registerMessage(PacketHandler.java:21) ~[PacketHandler.class:?]
	at com.seynox.adventum.network.PacketHandler.init(PacketHandler.java:14) ~[PacketHandler.class:?]
	at com.seynox.adventum.Adventum.init(Adventum.java:42) ~[Adventum.class:?]

 

How can i make this thread-safe?

[Cadiboo]

5 minutes ago, Seynox said:

How can i make this thread-safe?

This isn’t about thread safety, this is physical sides. Read https://mcforge.readthedocs.io/en/latest/concepts/sides/. Post your packet class

[Seynox]

3 minutes ago, Cadiboo said:

Post your packet class

 

PacketHandler :

Spoiler

public class PacketHandler {
	
	public static final SimpleNetworkWrapper INSTANCE = NetworkRegistry.INSTANCE.newSimpleChannel(Reference.MODID.toLowerCase());
	
	public static void init() {
		registerMessage(PacketJump.class, PacketJump.JumpMessage.class);
	}
	
	private static int nextPacketId = 0;
	  
	  private static void registerMessage(Class packet, Class message)
	  {
	    INSTANCE.registerMessage(packet, message, nextPacketId, Side.CLIENT);
	    INSTANCE.registerMessage(packet, message, nextPacketId, Side.SERVER);
	    nextPacketId++;
	}

}

 

 

JumpPacket :

Spoiler

public class PacketJump implements IMessageHandler<PacketJump.JumpMessage, IMessage>
{
	  @Override
		public IMessage onMessage(JumpMessage message, MessageContext ctx)
		{
		  EntityPlayer playerID = (ctx.side.isClient() ? Minecraft.getMinecraft().player : ctx.getServerHandler().player);
		  EntityPlayer player = (EntityPlayer)playerID.world.getEntityByID(message.playerid);
		  
		  boolean usedDoubleJump = false;
		  
		  ItemStack belt = BaublesApi.getBaublesHandler(player).getStackInSlot(3);
		  if(!belt.isEmpty() && belt.getItem() instanceof CloudInJar && !usedDoubleJump) {
			    usedDoubleJump = true;
				player.fallDistance = 0;
		  }
		  
		return null;
		}
	  
	  public static class JumpMessage implements IMessage
	  {
	    int playerid;
	    
	    public JumpMessage() {}
	    
	    public JumpMessage(int playerid)
	    {
	      this.playerid = playerid;
	    }
	    
	    @Override
	    public void fromBytes(ByteBuf buf)
	    {
	      this.playerid = ByteBufUtils.readVarInt(buf, 4);
	    }
	    
	    @Override
	    public void toBytes(ByteBuf buf)
	    {
	    	ByteBufUtils.writeVarInt(buf, playerid, 4);
	    }
	}
	  
	  
}

 

 

[Seynox]

5 minutes ago, diesieben07 said:

Why do you check the side in onMessage? Your messages should usually only go one way.

You cannot access client-only classes from common code (such as your IMessageHandler). You need to encapsulate such access using the @SidedProxy system

Can you give me an exemple? I have no idea how i can do this

 

[Seynox]

30 minutes ago, diesieben07 said:

https://mcforge.readthedocs.io/en/latest/concepts/sides/#sidedproxy

Fixed! Thanks you