bevy-rtc

bevy-rtc is a simple, multi-platform WebRTC networking library for client<->server topologies using Bevy.

• Simple: no knowledge of WebRTC is needed
• Easy unreliable (UDP-like) and reliable (TCP-like) networking on web
• Bevy system parameters for reading and writing packets
• Derive macros for creating protocols
• Support for unbounded and bounded buffers
• Easily read instantaneous and smoothed latency

Quickstart

For your client:

cargo add bevy-rtc -F client

For your server:

cargo add bevy-rtc -F server

Run the demos and instructions.

Compatibility

Cargo features

All features are opt-in.

• server - Provides necessary networking for server applications
• client - Provides necessary networking for client applications
• binary - Sends networking packets as binary instead of JSON (the default)

[!IMPORTANT]

• The client feature supports both WASM and native targets.
• The server feature is native only.

The server is native only because it serves a signaling server (and is the first peer of itself). While a WASM server is possible by depending on an external WebRTC signaling server, WASM is (currently) single threaded like JavaScript. If you really want a WASM server, I would accept PRs, but you probably don't want one!

Demos

There are two demos provided, a simple ping/pong demo and a painting game. Run one demo server, and any number of respective clients.

• Server (Native only)

cargo run -p painting-server

• Client (Native)

cargo run -p painting-client

• Client (Web)

cargo install wasm-server-runner
cd demos/painting-client
cargo run --target wasm32-unknown-unknown

Instructions

Protocols

Place your packet definitions in a shared location.

#[derive(Payload)]
pub enum MyPacket {
    Ping,
    Pong
}

Need help? See the demo protocol source or open an issue.

Server

• Ensure your client has the server feature

  cargo add bevy-rtc -F server
  

• Add the RtcServerPlugin to your app.

  .add_plugins(RtcServerPlugin { port: 3536 })
  

• Register your protocols as bounded or unbounded.

  • Bounded protocols will only keep the most recent N payloads received to read.
  • Unbounded protocols will keep all payloads using a resizable buffer.

  Payloads are only flushed by a system when they get read!
  It is recommended to keep your protocols bounded on the server.

  // Only choose one!
  .add_bounded_protocol::<MyPacket>(5) // Only keep the most recent 5 payloads for reading
  .add_unbounded_protocol::<MyPacket>() // Keep all payloads until read
  

• Add systems to read and send payloads.

  .add_systems(
      Update,
      |mut reader: NetworkReader<MyPacket>, mut writer: NetworkWriter<MyPacket>| {
          for (peer_id, packet) in reader.read() {
              if let MyPacket::Ping = packet {
                  writer.reliable_to_peer(peer_id, MyPacket::Pong);
              }
          }
      })
  

  Need help? See the ping-server or painting-server source or open an issue.

For the client:

• Ensure your client has the client feature

  cargo add bevy-rtc -F client
  

• Add the RtcClientPlugin to your app.

  .add_plugins(RtcClientPlugin)
  

• Register your protocols as bounded or unbounded.

  • Bounded protocols will only keep the most recent N payloads received to read.
  • Unbounded protocols will keep all payloads using a resizable buffer.

  Payloads are only flushed by a system when they get read!
  It is recommended to keep your protocols unbounded on the client.

  // Only choose one!
  .add_bounded_protocol::<MyPacket>(5) // Only keep the most recent 5 payloads for reading
  .add_unbounded_protocol::<MyPacket>() // Keep all payloads until read
  

• Add systems to read and send payloads.

  .add_systems(
      Update,
      {
          |mut writer: NetworkWriter<PingPayload>| {
              writer.reliable_to_host(PingPayload::Ping);
          }
      }
      .run_if(
          // Only send every second, and if we are connected.
          on_timer(Duration::from_secs(1)).and_then(
              state_exists_and_equals(RtcClientStatus::Connected),
          ),
      ),
  )
  .add_systems(Update, |mut reader: NetworkReader<PingPayload>| {
      for payload in reader.read() {
          if let PingPayload::Pong = payload {
              info!("..Received pong!");
          }
      }
  })
  

  Need help? See the ping-client or ping-server source or open an issue.