# Network

### Server

R-THAï is based on a UDP (User Datagram Protocol) protocol and created when executing the binary "r-type\_server".

All the game logic and the connexions are handled by the server and sent to the clients.

In order to start a server, you need to specify a port (8000 by default) in the entrypoint of the server part. The Server class is a singleton which run independently to the ECS.\
The server is asynchronous and the receiving IOService run in a thread.

Two LockedQueue (using mutexs) are responsible of the ingoing and outgoing data. In order to send data, you need to push a network::Message (wich is a std::array) into the outgoingQueue, incomming messages are handled in the HandleIncommingMessage class.

```cpp
network::Message msg;
//fill message
msg[0] = 0;
network::Server::getOutgoingMessages().push( 
network::ServerMessage(msg, std::vector()));
```

{% hint style="info" %}
src/ecs/systems/server/HandleIncommingMessage.hpp
{% endhint %}

### Client

A Client is created when executing the binary "r-type\_client" .

The menu permit you to select a room, or to set the options of your game like the sound volume.

The Client class is also a singleton using threads to hande incomming and outgoing data and work like the server (remember ingoing and outgoing lockedQueue ?). 

The client display every drawable entities from the server and himself (like the HUD) on the screen, and send the keyboards input to the server who handle them.

Because R-THAÏ is a multiplayer game, you can play on different client at the same time.

### Lobby

The lobby countain 4 rooms you can connect to. It interact with the client who can choose his room. It works by forking and executing the r-type\_server binary with different ports.

### RFC

The RFC (Request for comments) of our server/client protocol can be found here

{% content-ref url="network/rfc" %}
[rfc](https://cavonstavants-organization.gitbook.io/rtype/development-guidelines-and-how-tos/network/rfc)
{% endcontent-ref %}