# Renet
[](https://crates.io/crates/renet)
[](https://docs.rs/renet)
Renet is a network library for Server/Client games written in rust. It is focused on fast-paced games such as FPS, and competitive games.
Provides the following features:
- Client/Server connection management
- Message based communication using channels, they can have different guarantees:
- ReliableOrdered: guarantee of message delivery and order
- ReliableUnordered: guarantee of message delivery but not order
- Unreliable: no guarantee of message delivery or order
- Packet fragmentation and reassembly
- Authentication and encryption, using [renetcode](https://github.com/lucaspoffo/renet/tree/master/renetcode)
- The transport layer can be customizable. The default transport can be disabled and replaced with a custom one
## Channels
Renet communication is message based, and channels describe how the messages should be delivered.
Channels are unidirectional, `ConnectionConfig.client_channels_config` describes the channels that the clients sends to the server, and `ConnectionConfig.server_channels_config` describes the channels that the server sends to the clients.
Each channel has its own configuration `ChannelConfig`:
```rust
// No guarantee of message delivery or order
let send_type = SendType::Unreliable;
// guarantee of message delivery and order
let send_type = SendType::ReliableOrdered {
// If a message is lost, it will be resent after this duration
resend_time: Duration::from_millis(300)
};
// Guarantee of message delivery but not order
let send_type = SendType::ReliableUnordered {
resend_time: Duration::from_millis(300)
};
let channel_config = ChannelConfig {
// The id for the channel, must be unique within its own list,
// but it can be repeated between the server and client lists.
channel_id: 0,
// Maximum number of bytes that the channel may hold without acknowledgement of messages before becoming full.
max_memory_usage_bytes: 5 * 1024 * 1024, // 5 megabytes
send_type
};
```
## Usage
Renet aims to have a simple API that is easy to integrate with any code base. Poll for new messages at the start of a frame with `update`. Call `send_packets` from the transport layer to send packets to the client/server.
### Server
```rust
let mut server = RenetServer::new(ConnectionConfig::default());
// Setup transport layer
const SERVER_ADDR: SocketAddr = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 5000);
let socket: UdpSocket = UdpSocket::bind(SERVER_ADDR).unwrap();
let server_config = ServerConfig {
current_time: SystemTime::now().duration_since(SystemTime::UNIX_EPOCH).unwrap(),
max_clients: 64,
protocol_id: 0,
public_addresses: vec![SERVER_ADDR],
authentication: ServerAuthentication::Unsecure
};
let mut transport = NetcodeServerTransport::new(server_config, socket).unwrap();
// Your gameplay loop
loop {
let delta_time = Duration::from_millis(16);
// Receive new messages and update clients
server.update(delta_time);
transport.update(delta_time, &mut server)?;
// Check for client connections/disconnections
while let Some(event) = server.get_event() {
match event {
ServerEvent::ClientConnected { client_id } => {
println!("Client {client_id} connected");
}
ServerEvent::ClientDisconnected { client_id, reason } => {
println!("Client {client_id} disconnected: {reason}");
}
}
}
// Receive message from channel
for client_id in server.clients_id() {
// The enum DefaultChannel describe the channels used by the default configuration
while let Some(message) = server.receive_message(client_id, DefaultChannel::ReliableOrdered) {
// Handle received message
}
}
// Send a text message for all clients
server.broadcast_message(DefaultChannel::ReliableOrdered, "server message");
let client_id = ClientId::from_raw(0);
// Send a text message for all clients except for Client 0
server.broadcast_message_except(client_id, DefaultChannel::ReliableOrdered, "server message");
// Send message to only one client
server.send_message(client_id, DefaultChannel::ReliableOrdered, "server message");
// Send packets to clients using the transport layer
transport.send_packets(&mut server);
std::thread::sleep(delta_time); // Running at 60hz
}
```
### Client
```rust
let mut client = RenetClient::new(ConnectionConfig::default());
// Setup transport layer
const server_addr: SocketAddr = "127.0.0.1:5000".parse().unwrap();
let socket = UdpSocket::bind("127.0.0.1:0").unwrap();
let current_time = SystemTime::now().duration_since(SystemTime::UNIX_EPOCH).unwrap();
let authentication = ClientAuthentication::Unsecure {
server_addr,
client_id: 0,
user_data: None,
protocol_id: 0,
};
let mut transport = NetcodeClientTransport::new(current_time, authentication, socket).unwrap();
// Your gameplay loop
loop {
let delta_time = Duration::from_millis(16);
// Receive new messages and update client
client.update(delta_time);
transport.update(delta_time, &mut client).unwrap();
if client.is_connected() {
// Receive message from server
while let Some(message) = client.receive_message(DefaultChannel::ReliableOrdered) {
// Handle received message
}
// Send message
client.send_message(DefaultChannel::ReliableOrdered, "client text");
}
// Send packets to server using the transport layer
transport.send_packets(&mut client)?;
std::thread::sleep(delta_time); // Running at 60hz
}
```
## Demos
You can checkout the [echo example](https://github.com/lucaspoffo/renet/blob/master/renet/examples/echo.rs) for a simple usage of the library. Usage:
- Server: `cargo run --example echo -- server 5000`
- Client: `cargo run --example echo -- client 127.0.0.1:5000 CoolNickName`
Or you can look into the two demos that have more complex uses of renet:
Bevy Demo
Simple bevy application to demonstrate how you could replicate entities and send reliable messages as commands from the server/client using renet:
[Bevy Demo.webm](https://user-images.githubusercontent.com/35241085/180664609-f8c969e0-d313-45c0-9c04-8a116896d0bd.webm)
[Repository](https://github.com/lucaspoffo/renet/tree/master/demo_bevy)
Chat Demo
Simple chat application made with egui to demonstrate how you could handle errors, states transitions and client self hosting:
[Chat Demo.webm](https://user-images.githubusercontent.com/35241085/180664911-0baf7b35-c9d4-43ff-b793-5955060adebc.webm)
[Repository](https://github.com/lucaspoffo/renet/tree/master/demo_chat)