/usr/include/GeographicLib/GARS.hpp is in libgeographic-dev 1.45-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 | /**
* \file GARS.hpp
* \brief Header for GeographicLib::GARS class
*
* Copyright (c) Charles Karney (2015) <charles@karney.com> and licensed under
* the MIT/X11 License. For more information, see
* http://geographiclib.sourceforge.net/
**********************************************************************/
#if !defined(GEOGRAPHICLIB_GARS_HPP)
#define GEOGRAPHICLIB_GARS_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 {
/**
* \brief Conversions for the Global Area Reference System (GARS)
*
* The Global Area Reference System is described in
* - https://en.wikipedia.org/wiki/Global_Area_Reference_System
* - http://earth-info.nga.mil/GandG/coordsys/grids/gars.html
* .
* It provides a compact string representation of a geographic area
* (expressed as latitude and longitude). The classes Georef and Geohash
* implement similar compact representations.
*
* Example of use:
* \include example-GARS.cpp
**********************************************************************/
class GEOGRAPHICLIB_EXPORT GARS {
private:
typedef Math::real real;
static const std::string digits_;
static const std::string letters_;
enum {
lonorig_ = -180, // Origin for longitude
latorig_ = -90, // Origin for latitude
baselon_ = 10, // Base for longitude tiles
baselat_ = 24, // Base for latitude tiles
lonlen_ = 3,
latlen_ = 2,
baselen_ = lonlen_ + latlen_,
mult1_ = 2, // base precision = 1/2 degree
mult2_ = 2, // 6th char gives 2x more precision
mult3_ = 3, // 7th char gives 3x more precision
m_ = mult1_ * mult2_ * mult3_,
maxprec_ = 2,
maxlen_ = baselen_ + maxprec_,
};
GARS(); // Disable constructor
public:
/**
* Convert from geographic coordinates to GARS.
*
* @param[in] lat latitude of point (degrees).
* @param[in] lon longitude of point (degrees).
* @param[in] prec the precision of the resulting GARS.
* @param[out] gars the GARS string.
* @exception GeographicErr if \e lat is not in [−90°,
* 90°].
* @exception std::bad_alloc if memory for \e gars can't be allocated.
*
* \e prec specifies the precision of \e gars as follows:
* - \e prec = 0 (min), 30' precision, e.g., 006AG;
* - \e prec = 1, 15' precision, e.g., 006AG3;
* - \e prec = 2 (max), 5' precision, e.g., 006AG39.
*
* If \e lat or \e lon is NaN, then \e gars is set to "INVALID".
**********************************************************************/
static void Forward(real lat, real lon, int prec, std::string& gars);
/**
* Convert from GARS to geographic coordinates.
*
* @param[in] gars the GARS.
* @param[out] lat latitude of point (degrees).
* @param[out] lon longitude of point (degrees).
* @param[out] prec the precision of \e gars.
* @param[in] centerp if true (the default) return the center of the
* \e gars, otherwise return the south-west corner.
* @exception GeographicErr if \e gars is illegal.
*
* The case of the letters in \e gars is ignored. \e prec is in the range
* [0, 2] and gives the precision of \e gars as follows:
* - \e prec = 0 (min), 30' precision, e.g., 006AG;
* - \e prec = 1, 15' precision, e.g., 006AG3;
* - \e prec = 2 (max), 5' precision, e.g., 006AG39.
*
* If the first 3 characters of \e gars are "INV", then \e lat and \e lon
* are set to NaN and \e prec is unchanged.
**********************************************************************/
static void Reverse(const std::string& gars, real& lat, real& lon,
int& prec, bool centerp = true);
/**
* The angular resolution of a GARS.
*
* @param[in] prec the precision of the GARS.
* @return the latitude-longitude resolution (degrees).
*
* Internally, \e prec is first put in the range [0, 2].
**********************************************************************/
static Math::real Resolution(int prec) {
return 1/real(prec <= 0 ? mult1_ : (prec == 1 ? mult1_ * mult2_ :
mult1_ * mult2_ * mult3_));
}
/**
* The GARS precision required to meet a given geographic resolution.
*
* @param[in] res the minimum of resolution in latitude and longitude
* (degrees).
* @return GARS precision.
*
* The returned length is in the range [0, 2].
**********************************************************************/
static int Precision(real res) {
using std::abs; res = abs(res);
for (int prec = 0; prec < maxprec_; ++prec)
if (Resolution(prec) <= res)
return prec;
return maxprec_;
}
};
} // namespace GeographicLib
#if defined(_MSC_VER)
# pragma warning (pop)
#endif
#endif // GEOGRAPHICLIB_GARS_HPP
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