示例#1
0
        /// <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));
        }
示例#2
0
 /// <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)));
 }