gm-socketio

Socket.IO extension for GameMaker: Studio 2.3 HTML5
Preview on YouTube | Download latest release

Working with GameMaker: Studio 1.4 too, but won't be updated in the marketplace.

Features

Socket.IO enables real-time, bidirectional and event-based communication. It works on every platform, browser or device, focusing equally on reliability and speed.

This is an intuitive Game Maker Studio: 2 extension which enables fast Socket.IO communication for the client!

Quick Start

GML (GameMaker Client)

// 1. Connect to server
sio_connect_by_url("http://localhost:3000");

// 2. Add event listener (creates callback)
sio_addEvent("player_joined");

// 3. Send data to server
sio_emit("move", json_encode({x: x, y: y}));

JavaScript (Node.js Server)

const io = require('socket.io')(3000);

io.on('connection', (socket) => {
  console.log('Player connected:', socket.id);
  
  socket.on('move', (data) => {
    // Broadcast to all other players
    socket.broadcast.emit('player_moved', data);
  });
});

See the /examples folder for more complete working examples including multiplayer movement and chat.

Installation

1. Import the extension into your GameMaker project
2. Call sio_connect() or sio_connect_by_url(url) to connect
3. Done! No initialization objects needed.

Check out the examples to get started.

API Reference

sio_connect()

Connects to window.location. Call this before using other extension functions.

sio_connect_by_url(url)

Connect to a specific server URL instead of window.location.

sio_disconnect()

Closes the current connection.

sio_reconnect()

Reconnect using the previous address. Note: Socket.IO auto-reconnects by default, so you rarely need to call this manually.

sio_addEvent(eventName)

Creates an event listener. You must create a callback script following this naming convention:

Script name: gmcallback_sio_on_EVENTNAME (replace EVENTNAME with your event name, case sensitive)

Example:

// Register the event listener
sio_addEvent("create_player");

// Create a script named: gmcallback_sio_on_create_player
// Content:
var data = json_decode(argument[0]);
var username = data[? "username"];
var playerID = data[? "id"];

The callback receives argument[0] containing the data from the server. JSON objects are automatically converted to JSON strings.

sio_emit(eventName, data)

Send data to the server. Event name is case sensitive.

var map = ds_map_create();
map[? "username"] = "Player1";
map[? "x"] = x;
map[? "y"] = y;
sio_emit("create_player", json_encode(map));
ds_map_destroy(map);

sio_get_connection_status()

Returns true if connected to the server, false otherwise.

Development

# Install dependencies
yarn install

# Build the extension
yarn build

# Test the build (starts test server)
yarn test

# Clean build artifacts
yarn clean

Server Requirements

• Socket.IO server v4.x (compatible with socket.io-client v4.x bundled in this extension)
• See /test/server.js for a minimal working example

Resources

• Example projects
• Getting started blog post

License

MIT