/** Returns current device orientation.
         */
        int getDeviceOrientation()
        {
            int devOrientation;

            //Device orientation is obtained in AndroidCameraPlugin so we only need information about whether orientation is changed
#if UNITY_ANDROID && !UNITY_EDITOR
            int oldWidth  = ImageWidth;
            int oldHeight = ImageHeight;
            VisageTrackerNative._getCameraInfo(out Focus, out ImageWidth, out ImageHeight);

            if ((oldWidth != ImageWidth || oldHeight != ImageHeight) && ImageWidth != 0 && ImageHeight != 0 && oldWidth != 0 && oldHeight != 0)
            {
                devOrientation = (Orientation == 1) ? 0:1;
            }
            else
            {
                devOrientation = Orientation;
            }
#else
            if (Input.deviceOrientation == DeviceOrientation.Portrait)
            {
                devOrientation = 0;
            }
            else if (Input.deviceOrientation == DeviceOrientation.PortraitUpsideDown)
            {
                devOrientation = 2;
            }
            else if (Input.deviceOrientation == DeviceOrientation.LandscapeLeft)
            {
                devOrientation = 3;
            }
            else if (Input.deviceOrientation == DeviceOrientation.LandscapeRight)
            {
                devOrientation = 1;
            }
            else if (Input.deviceOrientation == DeviceOrientation.FaceUp)
            {
                devOrientation = Orientation;
            }
            else
            {
                devOrientation = 0;
            }
#endif
            return(devOrientation);
        }
        void GetCameraInfo()
        {
#if (UNITY_IPHONE) && UNITY_EDITOR
            return;
#endif
            VisageTrackerNative._getCameraInfo(out Focus, out ImageWidth, out ImageHeight);
#if UNITY_ANDROID && !UNITY_EDITOR
            if (ImageWidth == 0 || ImageHeight == 0)
            {
                return;
            }
#endif
            if (setCameraFieldOfView)
            {
                // set camera field of view
                float aspect = ImageWidth / (float)ImageHeight;
                float yRange = (ImageWidth > ImageHeight) ? 1.0f : 1.0f / aspect;
                Camera.main.fieldOfView = Mathf.Rad2Deg * 2.0f * Mathf.Atan(yRange / Focus);
            }
        }