Minimalist Multiplayer Game Server for Node.js. View documentation.

Read the blog post to understand the motivation behind this project.

Live demos:

• tanx (source-code)
• tic-tac-toe (source-code)
• LD35 entry: dotower (source-code)
• React Example (source-code)

Features

• WebSocket-based communication
• Room instantiation
• Binary data transfer (through msgpack)
• Delta-encoded state broadcasts (through fast-json-patch - RFC6902)
• Lag compensation (using timeframe, a Timeline implementation)
  • (Not automatic. You should apply the technique as you need, in the client and/or the server.)

TODO:

• "area of interest" updates/broadcasts

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Room instantiation diagram:

Room state diagram:

Room API

Properties

• clock - A ClockTimer instance
• timeline - A Timeline instance (see useTimeline)
• clients - Array of connected clients

Methods you should implement

• onJoin (client) - When a client joins the room
• onLeave (client) - When a client leaves the room
• onMessage (client, data) - When a client send a message
• onDispose () - Cleanup callback, called after there's no more clients on the room

Available methods

• setState( object ) - Set the current state to be broadcasted / patched.
• setSimulationInterval( callback[, milliseconds=16.6] ) - (Optional) Create the simulation interval that will change the state of the game. Default simulation interval: 16.6ms (60fps)
• setPatchRate( milliseconds ) - Set frequency the patched state should be sent to all clients. Default is 50ms (20fps).
• useTimeline([ maxSnapshots=10 ]) - (Optional) Keep state history between broadcatesd patches.
• send( client, data ) - Send data to a particular client.
• lock() - Lock the room to new clients.
• unlock() - Unlock the room to new clients.
• broadcast( data ) - Send data to all connected clients.
• disconnect() - Disconnect all clients then dispose.

Production usage

It's recommended to use a process manager to ensure the server will reload in case your application goes down.

pm2 start server.js --node-args="--harmony"

Redirect port 80 to target deployment port (e.g. 3000), to avoid running harmful code as sudoer: (read more)

sudo iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 3000

License

MIT