1 // Example of using the GeographicLib::GeodesicLine class
2
3 #include <iostream>
4 #include <iomanip>
5 #include <exception>
6 #include <cmath>
7 #include <GeographicLib/Geodesic.hpp>
8 #include <GeographicLib/GeodesicLine.hpp>
9 #include <GeographicLib/Constants.hpp>
10
11 using namespace std;
12 using namespace GeographicLib;
13
main()14 int main() {
15 try {
16 // Print waypoints between JFK and SIN
17 Geodesic geod(Constants::WGS84_a(), Constants::WGS84_f());
18 // Alternatively: const Geodesic& geod = Geodesic::WGS84();
19 double
20 lat1 = 40.640, lon1 = -73.779, // JFK
21 lat2 = 1.359, lon2 = 103.989; // SIN
22 GeodesicLine line = geod.InverseLine(lat1, lon1, lat2, lon2);
23 double ds0 = 500e3; // Nominal distance between points = 500 km
24 int num = int(ceil(line.Distance() / ds0)); // The number of intervals
25 cout << fixed << setprecision(3);
26 {
27 // Use intervals of equal length
28 double ds = line.Distance() / num;
29 for (int i = 0; i <= num; ++i) {
30 double lat, lon;
31 line.Position(i * ds, lat, lon);
32 cout << i << " " << lat << " " << lon << "\n";
33 }
34 }
35 {
36 // Slightly faster, use intervals of equal arc length
37 double da = line.Arc() / num;
38 for (int i = 0; i <= num; ++i) {
39 double lat, lon;
40 line.ArcPosition(i * da, lat, lon);
41 cout << i << " " << lat << " " << lon << "\n";
42 }
43 }
44 }
45 catch (const exception& e) {
46 cerr << "Caught exception: " << e.what() << "\n";
47 return 1;
48 }
49 }
50