node-gamepad

Bindings for Alex Diener's cross-platform gamepad code

The library is tiny and included inside this addon so you don't need any special libraries installed on your system like SDL.

To install as a dependency simple type the following in your project's folder:

npm install gamepad

Examples

var gamepad = require("gamepad");

// Initialize the library
gamepad.init()

// List the state of all currently attached devices
for (var i = 0, l = gamepad.numDevices(); i < l; i++) {
  console.log(i, gamepad.deviceAtIndex());
}

// Create a game loop and poll for events
setInterval(gamepad.processEvents, 16);
// Scan for new gamepads as a slower rate
setInterval(gamepad.detectDevices, 500);

// Listen for move events on all gamepads
gamepad.on("move", function (id, axis, value) {
  console.log("move", {
    id: id,
    axis: axis,
    value: value,
  });
});

// Listen for button up events on all gamepads
gamepad.on("up", function (id, num) {
  console.log("up", {
    id: id,
    num: num,
  });
});

// Listen for button down events on all gamepads
gamepad.on("down", function (id, num) {
  console.log("down", {
    id: id,
    num: num,
  });
});

Events

There are 5 event types attach, remove, down, up, and move. All pass the session id of the gamepad as the first argument.

The attach event also passes current state as the second arg to attach.

The down and up events also pass in the button id and timestamp after device session id.

The move event passes axis, value, old value and timestamp after session id.

Functions

gamepad.init()

Initializes gamepad library and detects initial devices. Call this before any other library function. If you want to receive attach events callbacks from devices detected in gamepad.init(), you must listen for attach before calling gamepad.init().

gamepad.shutdown()

Tears down all data structures created by the gamepad library and releases any memory that was allocated. It is not necessary to call this function at application termination, but it's provided in case you want to free memory associated with gamepads at some earlier time.

numDevices()

Returns the number of currently attached gamepad devices.

deviceAtIndex(deviceIndex)

Returns the specified gamepad's current state, or undefined if deviceIndex is out of bounds.

detectDevices()

Polls for any devices that have been attached since the last call to gamepad.detectDevices() or gamepad.init(). If any new devices are found, the attach event will be emitted once per newly detected device.

Note that depending on implementation, you may receive button and axis event callbacks for devices that have not yet been detected with gamepad.detectDevices(). You can safely ignore these events, but be aware that your callbacks might receive a device ID that hasn't been emitted as an attach event yet.

processEvents()

Reads pending input from all attached devices and emits the appropriate events, if any have been registered.

Developing

Publishing a release

This repository uses prebuild to create pre-built binaries (hosted on GitHub) for Windows, macOS, and Linux.

To trigger a new release, simply push a new tag. The TravisCI and Appveyor build scripts will see that tag, and publish binaries for it.

Once the builds have completed, the release can be published to npm via the normal command: npm publish.