/// <summary>
/// Returns the heading from one LatLng to another LatLng. Headings are
/// expressed in degrees clockwise from North within the range[-180, 180).
/// </summary>
/// <returns>The heading in degrees clockwise from north.</returns>
public static double computeHeading(Position from, Position to)
{
// http://williams.best.vwh.net/avform.htm#Crs
double fromLat = from.latitude.ToRadian();
double fromLng = from.longitude.ToRadian();
double toLat = to.latitude.ToRadian();
double toLng = to.longitude.ToRadian();
double dLng = toLng - fromLng;
double heading = Math.Atan2(
Math.Sin(dLng) * Math.Cos(toLat),
Math.Cos(fromLat) * Math.Sin(toLat) - Math.Sin(fromLat) * Math.Cos(toLat) * Math.Cos(dLng));
return(GmsMathUtils.Wrap(heading.ToDegrees(), -180, 180));
}
/// <summary>
/// Returns distance on the unit sphere; the arguments are in radians.
/// </summary>
private static double distanceRadians(double lat1, double lng1, double lat2, double lng2)
{
return(GmsMathUtils.ArcHav(GmsMathUtils.HavDistance(lat1, lat2, lng1 - lng2)));
}
