ADD: new track message, Entity class and Position class

libs/geographiclib/examples/example-TransverseMercatorExact.cpp

@@ -0,0 +1,37 @@
+// Example of using the GeographicLib::TransverseMercatorExact class
+
+#include <iostream>
+#include <iomanip>
+#include <exception>
+#include <GeographicLib/TransverseMercatorExact.hpp>
+
+using namespace std;
+using namespace GeographicLib;
+
+int main() {
+  try {
+    TransverseMercatorExact proj(Constants::WGS84_a(), Constants::WGS84_f(),
+                                 Constants::UTM_k0());
+    // Alternatively:
+    // const TransverseMercatorExact& proj = TransverseMercatorExact::UTM();
+    double lon0 = -75;          // Central meridian for UTM zone 18
+    {
+      // Sample forward calculation
+      double lat = 40.3, lon = -74.7; // Princeton, NJ
+      double x, y;
+      proj.Forward(lon0, lat, lon, x, y);
+      cout << x << " " << y << "\n";
+    }
+    {
+      // Sample reverse calculation
+      double x = 25e3, y = 4461e3;
+      double lat, lon;
+      proj.Reverse(lon0, x, y, lat, lon);
+      cout << lat << " " << lon << "\n";
+    }
+  }
+  catch (const exception& e) {
+    cerr << "Caught exception: " << e.what() << "\n";
+    return 1;
+  }
+}