Complete Gamepad.js code

## Gamepad.js
/**
 * (Note: Depends on window.requestAnimationFrame for polling.)
 *
 * An experimental Gamepad object for detecting
 *  and parsing gamepad input.
 *
 * Current code borrows heavily from Marcin Wichary's work:
 * http://www.html5rocks.com/en/tutorials/doodles/gamepad/
 *
 * Also uses deadzone values from
 * http://msdn.microsoft.com/en-us/library/windows/desktop/ee417001(v=vs.85).aspx
 * Left Stick: 8689/32767.0
 * Right Stick: 7849.0/32767.0
 * Shoulder0: 0.5
 * Shoulder1: 30.0/255.0
 *
 * @property {boolean}  supported                  If gamepads are supported in the current context
 * @property {boolean}  ticking                    If polling is currently taking place
 * @property {array}    gamepads                   The currently connected gamepads, if any
 * @property {float}    SHOULDER0_BUTTON_THRESHOLD The Shoulder0 ('LEFT_SHOULDER') deadzone for when a button is 'pressed'
 * @property {float}    SHOULDER1_BUTTON_THRESHOLD The Shoulder1 ('LEFT_SHOULDER_BOTTOM') deadzone for when a button is 'pressed'
 * @property {float}    LEFT_AXIS_THRESHOLD        The left axis deadzone for when an analogue input has 'moved'
 * @property {float}    RIGHT_AXIS_THRESHOLD       The right axis deadzone for when an analogue input has 'moved'
 * if(gamepad.supported) {
 *   if(gamepad.pressed(0, "FACE_1") {
 *    //Depending on the layout, either 'X', 'A', or 'O' was pressed on the first controller
 *   }
 * }
 */
var Gamepad = (function(self) {

  self.supported = (navigator.webkitGetGamepads && navigator.webkitGetGamepads()) ||
          !!navigator.webkitGamepads || !!navigator.mozGamepads ||
          !!navigator.msGamepads || !!navigator.gamepads ||
          (navigator.getGamepads && navigator.getGamepads());

  self.ticking = false;

  var BUTTONS = {
    FACE_1: 0,
    FACE_2: 1,
    FACE_3: 2,
    FACE_4: 3,
    LEFT_SHOULDER: 4,
    RIGHT_SHOULDER: 5,
    LEFT_SHOULDER_BOTTOM: 6,
    RIGHT_SHOULDER_BOTTOM: 7,
    SELECT: 8,
    START: 9,
    LEFT_ANALOGUE_STICK: 10,
    RIGHT_ANALOGUE_STICK: 11,
    PAD_UP: 12,
    PAD_DOWN: 13,
    PAD_LEFT: 14,
    PAD_RIGHT: 15,
    CENTER_BUTTON: 16
  };

  self.SHOULDER0_BUTTON_THRESHOLD = .5;
  self.SHOULDER1_BUTTON_THRESHOLD = 30.0 / 255.0;
  self.RIGHT_AXIS_THRESHOLD = 7849.0 / 32767.0;
  self.LEFT_AXIS_THRESHOLD = 8689 / 32767.0;
  self.gamepads = [];
  var prevRawGamepadTypes = [];
  var prevTimestamps = [];

  if (self.supported) {
    // Older Firefox
    window.addEventListener('MozGamepadConnected',
            onGamepadConnect, false);
    window.addEventListener('MozGamepadDisconnected',
            onGamepadDisconnect, false);

    //W3C Specification
    window.addEventListener('gamepadconnected', onGamepadConnect, false);
    window.addEventListener('gamepaddisconnected', onGamepadDisconnect, false);

    // Chrome
    if (navigator.webkitGetGamepads && navigator.webkitGetGamepads()) {
      startPolling();
    }

    //CocoonJS
    if(navigator.getGamepads && navigator.getGamepads()) {
      startPolling();
    }
  }

  /**
   * Starts the polling
   * @private
   * @see onGamepadConnect
   */
  function startPolling() {
    if (!self.ticking) {
      self.ticking = true;
      tick();
    }
  }

  /**
   * Does one 'tick' and prepares for the next
   * @private
   * @see pollStatus
   */
  function tick() {
    pollStatus();
    if (self.ticking) {
      window.requestAnimationFrame(tick);
    }
  }

  /**
   * Stops the polling
   * @private
   */
  function stopPolling() {
    self.ticking = false;
  }

  /**
   * Compares timestamps for changes
   * @see pollGamepads()
   */
  function pollStatus() {
    pollGamepads();
    for (var i in self.gamepads) {
      var gamepad = self.gamepads[i];
      if (gamepad.timestamp &&
              (gamepad.timestamp === prevTimestamps[i])) {
        continue;
      }
      prevTimestamps[i] = gamepad.timestamp;
    }
  }

  /**
   * Polls the navigator.*Gamepads object for all gamepads connected
   */
  function pollGamepads() {
    var rawGamepads =
            (navigator.webkitGetGamepads && navigator.webkitGetGamepads()) ||
            navigator.webkitGamepads || navigator.mozGamepads ||
            navigator.msGamepads || navigator.gamepads ||
            (navigator.getGamepads && navigator.getGamepads());
    if (rawGamepads) {
      self.gamepads = [];
      for (var i = 0; i < rawGamepads.length; i++) {
        if (typeof rawGamepads[i] !== prevRawGamepadTypes[i]) {
          prevRawGamepadTypes[i] = typeof rawGamepads[i];
        }
        if (rawGamepads[i]) {
          self.gamepads.push(rawGamepads[i]);
        }
      }
    }
  }
  /**
   * Returns if a specific button on a certain gamepad was pressed
   * @param {number} pad  The Gamepad to check
   * @param {string} buttonId The button to check
   * @returns {boolean} If the button on the specific gamepad is currently pressed
   */
  self.pressed = function(pad, buttonId) {
    if (self.gamepads[pad] && BUTTONS[buttonId]) {
      var buttonIndex = BUTTONS[buttonId];
      if (buttonIndex === 4 || buttonIndex === 5) {
        return self.gamepads[pad].buttons[buttonIndex] > self.SHOULDER0_BUTTON_THRESHOLD;
      } else if (buttonIndex === 6 || buttonIndex === 7) {
        return self.gamepads[pad].buttons[buttonIndex] > self.SHOULDER1_BUTTON_THRESHOLD;
      } else {
        return self.gamepads[pad].buttons[buttonIndex] > 0.5;
      }
    } else {
      return false;
    }
  };

  /**
   * Returns the amount of movement from the deadzone (-1 to 1)
   * @param {number} pad  The Gamepad to check
   * @param {string} axisId The axis and dimension to check
   * @returns {number} The amount of movement, if any
   */
  self.moved = function(pad, axisId) {
    if (self.gamepads[pad]) {
      if (axisId === "LEFT_X") {
        if (self.gamepads[pad].axes[0] < -self.LEFT_AXIS_THRESHOLD ||
                self.gamepads[pad].axes[0] > self.LEFT_AXIS_THRESHOLD) {
          return self.gamepads[pad].axes[0];
        }
      } else if (axisId === "LEFT_Y") {
        if (self.gamepads[pad].axes[1] < -self.LEFT_AXIS_THRESHOLD ||
                self.gamepads[pad].axes[1] > self.LEFT_AXIS_THRESHOLD) {
          return self.gamepads[pad].axes[1];
        }
      } else if (axisId === "RIGHT_X") {
        if (self.gamepads[pad].axes[2] < -self.RIGHT_AXIS_THRESHOLD ||
                self.gamepads[pad].axes[2] > self.RIGHT_AXIS_THRESHOLD) {
          return self.gamepads[pad].axes[2];
        }
      } else if (axisId === "RIGHT_Y") {
        if (self.gamepads[pad].axes[3] < -self.RIGHT_AXIS_THRESHOLD ||
                self.gamepads[pad].axes[3] > self.RIGHT_AXIS_THRESHOLD) {
          return self.gamepads[pad].axes[3];
        }
      }
    } else {
      return 0;
    }
  };
  /**
   * Adds a gamepad when connected and starts the polling
   * @param {EventObject} event A 'MozGamepadConnected' or 'gamepadconnected' event object
   */
  function onGamepadConnect(event) {
    var gamepad = event.gamepad;
    self.gamepads[event.gamepad.id] = gamepad;
    self.startPolling();
  }

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

  return self;

})(Gamepad || {});