Georef.hpp

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#if !defined(GEOGRAPHICLIB_GEOREF_HPP)
#define GEOGRAPHICLIB_GEOREF_HPP 1

#include <GeographicLib/Constants.hpp>

#if defined(_MSC_VER)
// Squelch warnings about dll vs string
#  pragma warning (push)
#  pragma warning (disable: 4251)
#endif

namespace GeographicLib {

  class GEOGRAPHICLIB_EXPORT Georef {
  private:
    typedef Math::real real;
    static const char* const digits_;
    static const char* const lontile_;
    static const char* const lattile_;
    static const char* const degrees_;
    enum {
      tile_ = 15,               // The size of tile in degrees
      lonorig_ = -180,          // Origin for longitude
      latorig_ = -90,           // Origin for latitude
      base_ = 10,               // Base for minutes
      baselen_ = 4,
      maxprec_ = 11,            // approximately equivalent to MGRS class
      maxlen_ = baselen_ + 2 * maxprec_,
    };
    Georef();                     // Disable constructor

  public:

    static void Forward(real lat, real lon, int prec, std::string& georef);

    static void Reverse(const std::string& georef, real& lat, real& lon,
                        int& prec, bool centerp = true);

    static Math::real Resolution(int prec) {
      if (prec < 1)
        return real(prec < 0 ? 15 : 1);
      else {
        using std::pow;
        // Treat prec = 1 as 2.
        prec = (std::max)(2, (std::min)(int(maxprec_), prec));
        // Need extra real because, since C++11, pow(float, int) returns double
        return 1/(60 * real(pow(real(base_), prec - 2)));
      }
    }

    static int Precision(real res) {
      using std::abs; res = abs(res);
      for (int prec = 0; prec < maxprec_; ++prec) {
        if (prec == 1)
          continue;
        if (Resolution(prec) <= res)
          return prec;
      }
      return maxprec_;
    }

  };

} // namespace GeographicLib

#if defined(_MSC_VER)
#  pragma warning (pop)
#endif

#endif  // GEOGRAPHICLIB_GEOREF_HPP