ADD: new track message, Entity class and Position class

libs/geographiclib/develop/M12zero.cpp

@@ -0,0 +1,42 @@
+#include <iostream>
+#include <GeographicLib/Utility.hpp>
+#include <GeographicLib/GeodesicExact.hpp>
+#include <GeographicLib/GeodesicLineExact.hpp>
+
+int main(int argc, const char* const argv[]) {
+  try {
+    using namespace GeographicLib;
+    typedef Math::real real;
+    Utility::set_digits();
+    real a = 2 / Math::pi();
+    if (argc != 2) {
+      std::cout << "Usage: M12zero f\n";
+      return 1;
+    }
+    real f = Utility::fract<real>(std::string(argv[1]));
+
+    GeodesicExact g(a, f);
+    GeodesicLineExact l(g, 90, 0, 0);
+    real s12 = a * Math::pi()/2;
+    real lat2, lon2, azi2, m12, M12, M21, ds12;
+    for (int i = 0; i < 20; ++i) {
+      using std::abs;
+      l.Position(s12, lat2, lon2, azi2, m12, M12, M21);
+      ds12 = m12 * M12 / (1 - M12 * M21);
+      s12 = abs(s12 + ds12);
+    }
+    real q;
+    g.Inverse(0,0,90,0,q);
+    int p = 16 + Math::extra_digits();
+    p = 20;
+    std::cout << std::fixed << std::setprecision(p) << s12 << " " << q << "\n";
+  }
+  catch (const std::exception& e) {
+    std::cerr << "Caught exception: " << e.what() << "\n";
+    return 1;
+  }
+  catch (...) {
+    std::cerr << "Caught unknown exception\n";
+    return 1;
+  }
+}