[1.8] package problem

knokko · October 31, 2015

I am trying to render energy in cables in my mod.

The TileEntity sends a packet to the Client that says where to render the energy.

But between toBytes(ByteBuf and fromBytes(ByteBuf, it causes several Exceptions and a crash.

There seems to be a problem with the discriminator, it seems to be -1 when the ID of the message is 0.

Here is the message registered:

public static SimpleNetworkWrapper network;

@EventHandler
public void preInit(FMLPreInitializationEvent event){
	HyperItems.load();
	HyperBlocks.load();
	network = NetworkRegistry.INSTANCE.newSimpleChannel("knokko Hyper Combat");
	network.registerMessage(CableMessage.Handler.class, CableMessage.class, 0, Side.CLIENT);
}

Here is the packet class:

public class CableMessage implements IMessage {

public static final byte[] BYTES = new byte[]{64,32,16,8,4,2,1};

private int x;
private int y;
private int z;
private boolean[] energy;

public CableMessage() {}

public CableMessage(int x, int y, int z, boolean[] energy){
	this.x = x;
	this.y = y;
	this.z = z;
	this.energy = energy;
}

@Override
public void fromBytes(ByteBuf buf) {
	System.out.println("decode from bytes...");
	x = buf.getInt(0);
	y = buf.getInt(4);
	z = buf.getInt(;
	energy = toBinair(buf.getByte(12));
	System.out.println("decoded from bytes");
}

@Override
public void toBytes(ByteBuf buf) {
	System.out.println("convert to bytes...");
	buf.setInt(0, x);
	buf.setInt(4, y);
	buf.setInt(8, z);
	buf.setByte(12, fromBinair(new boolean[]{energy[0], energy[1], energy[2], energy[3], energy[4], energy[5], false, false}));
	System.out.println("converted to bytes");
}

public static class Handler implements IMessageHandler<CableMessage, IMessage> {
//Gets the TileEntity at the given position and marks the places to render the energy
	@Override
	public IMessage onMessage(final CableMessage message, MessageContext ctx) {
		IThreadListener listener = Minecraft.getMinecraft();
		listener.addScheduledTask(new Runnable(){
			@Override
			public void run(){
				World world = Minecraft.getMinecraft().theWorld;
				TileEntity entity = world.getTileEntity(new BlockPos(message.x, message.y, message.z));
				if(world.isRemote && entity instanceof TileEntityCable)
					((TileEntityCable)entity).isEnergy = new boolean[]{message.energy[0], message.energy[1], message.energy[2], message.energy[3], message.energy[4], message.energy[5]};
				System.out.println("packet arrived: energy = " + message.energy + " and entity = " + entity);
		}});
		return null;
	}
}
//gets 8 booleans from 1 byte
public static boolean[] toBinair(byte b){
	boolean[] bools = new boolean[8];
	if(b >= 0)
		bools[7] = true;
	else {
		b++;
		b *= -1;
	}
	byte t = 0;
	while(t < 7){
		if(b >= BYTES[t]){
			b -= BYTES[t];
			bools[t] = true;
		}
		++t;
	}
	return bools;
}
//stores 8 booleans into 1 byte
public static byte fromBinair(boolean[] bools){
	byte b = 0;
	int t = 0;
	while(t < 7){
		if(bools[t])
			b += BYTES[t];
		++t;
	}
	if(!bools[7]){
		b *= -1;
		b--;
	}
	return b;
}
}

Here is the method where the packet is sent:

@Override
public int drainEnergy(EnumFacing facing, int requestedAmount) {
	//isEnergy = new boolean[6];
	System.out.println("drainEnergy...");
	int energy = 0;
//isDraining is here to prevent infinite loops
	if(!isDraining){
		if(capacity == 0){
			Block block = worldObj.getBlockState(pos).getBlock();
			if(block instanceof BlockCable)
				capacity = ((BlockCable) block).getCapacity();
		}
		if(requestedAmount > capacity)
			requestedAmount = capacity;
		isDraining = true;
		int t = 0;
		while(t < EnumFacing.values().length){
			if(energy >= requestedAmount){
				isDraining = false;
//sending the packet...
				System.out.println("starting to send message...");
				HyperCombat.network.sendToAllAround(new CableMessage(pos.getX(), pos.getY(), pos.getZ(), isEnergy), new TargetPoint(worldObj.provider.getDimensionId(), pos.getX(), pos.getY(), pos.getZ(), 32));
				System.out.println("message send... hopefully");
				return energy;
			}
			if(facing != EnumFacing.values()[t].getOpposite()){
				int extra = drain(EnumFacing.values()[t], requestedAmount - energy);
				energy += extra;
				if(extra > 0)
					isEnergy[t] = true;
			}
			++t;
		}
	}
	isDraining = false;
	if(energy > 0)
		isEnergy[facing.ordinal()] = true;
	System.out.println("starting to send message...");
	HyperCombat.network.sendToAllAround(new CableMessage(pos.getX(), pos.getY(), pos.getZ(), isEnergy), new TargetPoint(worldObj.provider.getDimensionId(), pos.getX(), pos.getY(), pos.getZ(), 32));
	System.out.println("message send... hopefully");
	return energy;
}

Here is the important part of the console log:

[11:51:02] [server thread/INFO] [FML]: Injecting existing block and item data into this server instance

[11:51:02] [server thread/INFO] [FML]: Applying holder lookups

[11:51:02] [server thread/INFO] [FML]: Holder lookups applied

[11:51:02] [server thread/INFO] [FML]: Loading dimension 0 (New World) (net.minecraft.server.integrated.IntegratedServer@5af49ae5)

[11:51:02] [server thread/INFO] [FML]: Loading dimension 1 (New World) (net.minecraft.server.integrated.IntegratedServer@5af49ae5)

[11:51:02] [server thread/INFO] [FML]: Loading dimension -1 (New World) (net.minecraft.server.integrated.IntegratedServer@5af49ae5)

[11:51:02] [server thread/INFO]: Preparing start region for level 0

[11:51:03] [server thread/INFO] [sTDOUT]: [knokko.tileentity.TileEntityCable:drainEnergy:33]: drainEnergy...

[11:51:03] [server thread/INFO] [sTDOUT]: [knokko.tileentity.TileEntityCable:drainEnergy:65]: starting to send message...

[11:51:04] [server thread/INFO] [sTDOUT]: [knokko.packet.CableMessage:toBytes:44]: convert to bytes...

[11:51:04] [server thread/INFO] [sTDOUT]: [knokko.packet.CableMessage:toBytes:49]: converted to bytes

[11:51:04] [server thread/INFO] [sTDOUT]: [knokko.tileentity.TileEntityCable:drainEnergy:67]: message send... hopefully

[11:51:04] [server thread/INFO] [sTDOUT]: [knokko.tileentity.TileEntityCable:drainEnergy:65]: starting to send message...

[11:51:04] [server thread/INFO] [sTDOUT]: [knokko.packet.CableMessage:toBytes:44]: convert to bytes...

[11:51:04] [server thread/INFO] [sTDOUT]: [knokko.packet.CableMessage:toBytes:49]: converted to bytes

[11:51:04] [server thread/INFO] [sTDOUT]: [knokko.tileentity.TileEntityCable:drainEnergy:67]: message send... hopefully

[11:51:04] [server thread/INFO] [sTDOUT]: [knokko.tileentity.TileEntityCable:drainEnergy:33]: drainEnergy...

[11:51:04] [server thread/INFO] [sTDOUT]: [knokko.tileentity.TileEntityCable:drainEnergy:65]: starting to send message...

[11:51:04] [server thread/INFO] [sTDOUT]: [knokko.packet.CableMessage:toBytes:44]: convert to bytes...

[11:51:04] [server thread/INFO] [sTDOUT]: [knokko.packet.CableMessage:toBytes:49]: converted to bytes

[11:51:04] [server thread/INFO] [sTDOUT]: [knokko.tileentity.TileEntityCable:drainEnergy:67]: message send... hopefully

[11:51:04] [server thread/INFO]: Changing view distance to 12, from 10