example-GeodesicLine.cs

using System;
using NETGeographicLib;

namespace example_GeodesicLine
{
    class Program
    {
        static void Main(string[] args)
        {
            try
            {
                // Print waypoints between JFK and SIN
                Geodesic geod = new Geodesic(); // WGS84
                double
                    lat1 = 40.640, lon1 = -73.779, // JFK
                    lat2 = 1.359, lon2 = 103.989; // SIN
                double s12, azi1, azi2,
                    a12 = geod.Inverse(lat1, lon1, lat2, lon2, out s12, out azi1, out azi2);
                GeodesicLine line = new GeodesicLine(geod, lat1, lon1, azi1, Mask.ALL);
                // Alternatively GeodesicLine line = geod.Line(lat1, lon1, azi1, Mask.ALL);
                double ds = 500e3;          // Nominal distance between points = 500 km
                int num = (int)(Math.Ceiling(s12 / ds)); // The number of intervals
                {
                    // Use intervals of equal length
                    ds = s12 / num;
                    for (int i = 0; i <= num; ++i)
                    {
                        double lat, lon;
                        line.Position(i * ds, out lat, out lon);
                        Console.WriteLine(String.Format("i: {0} Latitude: {1} Longitude: {2}", i, lat, lon));
                    }
                }
                {
                    // Slightly faster, use intervals of equal arc length
                    double da = a12 / num;
                    for (int i = 0; i <= num; ++i)
                    {
                        double lat, lon;
                        line.ArcPosition(i * da, out lat, out lon);
                        Console.WriteLine(String.Format("i: {0} Latitude: {1} Longitude: {2}", i, lat, lon));
                    }
                }
            }
            catch (GeographicErr e)
            {
                Console.WriteLine(String.Format("Caught exception: {0}", e.Message));
            }
        }
    }
}