private void tracker_GazeDataReceived(IEyeTrackerDriver sender, GazeData gaze)
{
double?distance = gaze.GetEyeDistance();
double?relativeEyeDistance = gaze.GetRelativeEyeDistance();
var recommendation = GetRecommendation(relativeEyeDistance);
// Point (0,0,0) of the TrackBox Coordinate System is in the top right corner nearest to the eye tracker from the user's
// point of view (see Figure 3, Tobii Analytics SDK Developers Guide, p. 15), not the top left corner like the screen is,
// so we swap the X coordinate. Y coordinate is still in the right direction.
var leftEyePosition = new Point2(1 - gaze.LeftEye.EyePosition3DRelative.X, gaze.LeftEye.EyePosition3DRelative.Y);
var rightEyePosition = new Point2(1 - gaze.RightEye.EyePosition3DRelative.X, gaze.RightEye.EyePosition3DRelative.Y);
PositionChanged?.Invoke(this, new EyesPosition(leftEyePosition, gaze.Validity.HasLeftEye(),
rightEyePosition, gaze.Validity.HasRightEye(),
distance, relativeEyeDistance, recommendation));
}
