title: Airplane Animatiton on GMap.net not flight in straight line
body: <p>i am trying to ceate plane animation on gmap.net
  I created the route like that:</p>
  <pre><code>        Map.Markers.Remove(_route);
          _route = new GMapRoute(PointsList.Select(x =&gt; x.Location).ToList());
          Map.Markers.Add(_route);
  </code></pre>
  <p>The start flight method is :</p>
  <pre><code>while (!IsFlightEnded())
          {
              CalculateNextPoint();
              _plane.Position = _nextPointInRoute;
              await Task.Delay(250);
          }
  </code></pre>
  <p>The calculate next point is:</p>
  <pre><code>    private void CalculateNextPoint()
      {
          _nextPointInRoute.Lat += LattitudeDifference() / 100;
          _nextPointInRoute.Lng += LongitudeDifference() / 100;
      }
  </code></pre>
  <p>the LattitudeDifference is calculate the difference between the destanation's lat to the source's lat.
  Same thing to the LongitudeDifference.</p>
  <p>The problem is that the animation not moving on the straight route, and it is going like parabola
  I even tried to use linear equation but it was the same.</p>