code: function(eventData) {
              var data;
              if (window.DeviceOrientationEvent) {
                  data = {
                      // gamma is the left-to-right tilt in degrees, where right is positive
                      tiltLR: eventData.gamma,
                      // beta is the front-to-back tilt in degrees, where front is positive
                      tiltFB: eventData.beta,
                      // alpha is the compass direction the device is facing in degrees
                      dir: eventData.alpha,
                      // deviceorientation does not provide this data
                      motUD: null
                  };
              } else if (window.OrientationEvent) {
                  data = {
                      // x is the left-to-right tilt from -1 to +1, so we need to convert to degrees
                      tiltLR: eventData.x * 90,
                      // y is the front-to-back tilt from -1 to +1, so we need to convert to degrees
                      // We also need to invert the value so tilting the device towards us (forward)
                      // results in a positive value.
                      tiltFB: eventData.y * -90,
                      // MozOrientation does not provide this data
                      dir: null,
                      // z is the vertical acceleration of the device
                      motUD: eventData.z
                  };
              }
  
              Crafty.device._deviceOrientationCallback(data);
          }
docs: The HTML5 DeviceOrientation event returns three pieces of data:
  * alpha the direction the device is facing according to the compass
  * beta the angle in degrees the device is tilted front-to-back
  * gamma the angle in degrees the device is tilted left-to-right.
  * The angles values increase as you tilt the device to the right or towards you.
  
  Since Firefox uses the MozOrientationEvent which returns similar data but
  using different parameters and a different measurement system, we want to
  normalize that before we pass it to our _deviceOrientationCallback function.
  
  @param eventData HTML5 DeviceOrientation event