Gamepad3

Gamepad.js

/**
   * In Firefox only, adds a gamepad when connected and starts the polling
   * @param {EventObject} event A 'MozGamepadConnected' event object
   */
  function onGamepadConnect(event) {
    var gamepad = event.gamepad;
    self.gamepads[event.gamepad.id] = gamepad;
    startPolling();
  }

  /**
   * In Firefox only, sets a disconnected gamepad to 'null'
   * @param {EventObject} event A 'MozGamepadDisconnected' event object
   */
  function onGamepadDisconnect(event) {
    self.gamepads[event.gamepad.id] = null;
    if (self.gamepads.length === 0) {
      stopPolling();
    }