projections/proj/gnom.hpp

0001 // Boost.Geometry - gis-projections (based on PROJ4)
0002
0003 // Copyright (c) 2008-2015 Barend Gehrels, Amsterdam, the Netherlands.
0004
0005 // This file was modified by Oracle on 2017, 2018, 2019.
0006 // Modifications copyright (c) 2017-2019, Oracle and/or its affiliates.
0007 // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle.
0008
0009 // Use, modification and distribution is subject to the Boost Software License,
0010 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
0011 // http://www.boost.org/LICENSE_1_0.txt)
0012
0013 // This file is converted from PROJ4, http://trac.osgeo.org/proj
0014 // PROJ4 is originally written by Gerald Evenden (then of the USGS)
0015 // PROJ4 is maintained by Frank Warmerdam
0016 // PROJ4 is converted to Boost.Geometry by Barend Gehrels
0017
0018 // Last updated version of proj: 5.0.0
0019
0020 // Original copyright notice:
0021
0022 // Permission is hereby granted, free of charge, to any person obtaining a
0023 // copy of this software and associated documentation files (the "Software"),
0024 // to deal in the Software without restriction, including without limitation
0025 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
0026 // and/or sell copies of the Software, and to permit persons to whom the
0027 // Software is furnished to do so, subject to the following conditions:
0028
0029 // The above copyright notice and this permission notice shall be included
0030 // in all copies or substantial portions of the Software.
0031
0032 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
0033 // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
0034 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
0035 // THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
0036 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
0037 // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
0038 // DEALINGS IN THE SOFTWARE.
0039
0040 #ifndef BOOST_GEOMETRY_PROJECTIONS_GNOM_HPP
0041 #define BOOST_GEOMETRY_PROJECTIONS_GNOM_HPP
0042
0043 #include <boost/config.hpp>
0044 #include <boost/geometry/util/math.hpp>
0045 #include <boost/math/special_functions/hypot.hpp>
0046
0047 #include <boost/geometry/srs/projections/impl/base_static.hpp>
0048 #include <boost/geometry/srs/projections/impl/base_dynamic.hpp>
0049 #include <boost/geometry/srs/projections/impl/projects.hpp>
0050 #include <boost/geometry/srs/projections/impl/factory_entry.hpp>
0051
0052 namespace boost { namespace geometry
0053 {
0054
0055 namespace projections
0056 {
0057     #ifndef DOXYGEN_NO_DETAIL
0058     namespace detail { namespace gnom
0059     {
0060
0061             static const double epsilon10 = 1.e-10;
0062             enum mode_type {
0063                 n_pole = 0,
0064                 s_pole = 1,
0065                 equit  = 2,
0066                 obliq  = 3
0067             };
0068
0069             template <typename T>
0070             struct par_gnom
0071             {
0072                 T    sinph0;
0073                 T    cosph0;
0074                 mode_type mode;
0075             };
0076
0077             template <typename T, typename Parameters>
0078             struct base_gnom_spheroid
0079             {
0080                 par_gnom<T> m_proj_parm;
0081
0082                 // FORWARD(s_forward)  spheroid
0083                 // Project coordinates from geographic (lon, lat) to cartesian (x, y)
0084                 inline void fwd(Parameters const& , T const& lp_lon, T const& lp_lat, T& xy_x, T& xy_y) const
0085                 {
0086                     T  coslam, cosphi, sinphi;
0087
0088                     sinphi = sin(lp_lat);
0089                     cosphi = cos(lp_lat);
0090                     coslam = cos(lp_lon);
0091
0092                     switch (this->m_proj_parm.mode) {
0093                     case equit:
0094                         xy_y = cosphi * coslam;
0095                         break;
0096                     case obliq:
0097                         xy_y = this->m_proj_parm.sinph0 * sinphi + this->m_proj_parm.cosph0 * cosphi * coslam;
0098                         break;
0099                     case s_pole:
0100                         xy_y = - sinphi;
0101                         break;
0102                     case n_pole:
0103                         xy_y = sinphi;
0104                         break;
0105                     }
0106
0107                     if (xy_y <= epsilon10) {
0108                         BOOST_THROW_EXCEPTION( projection_exception(error_tolerance_condition) );
0109                     }
0110
0111                     xy_x = (xy_y = 1. / xy_y) * cosphi * sin(lp_lon);
0112                     switch (this->m_proj_parm.mode) {
0113                     case equit:
0114                         xy_y *= sinphi;
0115                         break;
0116                     case obliq:
0117                         xy_y *= this->m_proj_parm.cosph0 * sinphi - this->m_proj_parm.sinph0 * cosphi * coslam;
0118                         break;
0119                     case n_pole:
0120                         coslam = - coslam;
0121                         BOOST_FALLTHROUGH;
0122                     case s_pole:
0123                         xy_y *= cosphi * coslam;
0124                         break;
0125                     }
0126                 }
0127
0128                 // INVERSE(s_inverse)  spheroid
0129                 // Project coordinates from cartesian (x, y) to geographic (lon, lat)
0130                 inline void inv(Parameters const& par, T xy_x, T xy_y, T& lp_lon, T& lp_lat) const
0131                 {
0132                     static const T half_pi = detail::half_pi<T>();
0133
0134                     T  rh, cosz, sinz;
0135
0136                     rh = boost::math::hypot(xy_x, xy_y);
0137                     sinz = sin(lp_lat = atan(rh));
0138                     cosz = sqrt(1. - sinz * sinz);
0139
0140                     if (fabs(rh) <= epsilon10) {
0141                         lp_lat = par.phi0;
0142                         lp_lon = 0.;
0143                     } else {
0144                         switch (this->m_proj_parm.mode) {
0145                         case obliq:
0146                             lp_lat = cosz * this->m_proj_parm.sinph0 + xy_y * sinz * this->m_proj_parm.cosph0 / rh;
0147                             if (fabs(lp_lat) >= 1.)
0148                                 lp_lat = lp_lat > 0. ? half_pi : -half_pi;
0149                             else
0150                                 lp_lat = asin(lp_lat);
0151                             xy_y = (cosz - this->m_proj_parm.sinph0 * sin(lp_lat)) * rh;
0152                             xy_x *= sinz * this->m_proj_parm.cosph0;
0153                             break;
0154                         case equit:
0155                             lp_lat = xy_y * sinz / rh;
0156                             if (fabs(lp_lat) >= 1.)
0157                                 lp_lat = lp_lat > 0. ? half_pi : -half_pi;
0158                             else
0159                                 lp_lat = asin(lp_lat);
0160                             xy_y = cosz * rh;
0161                             xy_x *= sinz;
0162                             break;
0163                         case s_pole:
0164                             lp_lat -= half_pi;
0165                             break;
0166                         case n_pole:
0167                             lp_lat = half_pi - lp_lat;
0168                             xy_y = -xy_y;
0169                             break;
0170                         }
0171                         lp_lon = atan2(xy_x, xy_y);
0172                     }
0173                 }
0174
0175                 static inline std::string get_name()
0176                 {
0177                     return "gnom_spheroid";
0178                 }
0179
0180             };
0181
0182             // Gnomonic
0183             template <typename Parameters, typename T>
0184             inline void setup_gnom(Parameters& par, par_gnom<T>& proj_parm)
0185             {
0186                 static const T half_pi = detail::half_pi<T>();
0187
0188                 if (fabs(fabs(par.phi0) - half_pi) < epsilon10) {
0189                     proj_parm.mode = par.phi0 < 0. ? s_pole : n_pole;
0190                 } else if (fabs(par.phi0) < epsilon10) {
0191                     proj_parm.mode = equit;
0192                 } else {
0193                     proj_parm.mode = obliq;
0194                     proj_parm.sinph0 = sin(par.phi0);
0195                     proj_parm.cosph0 = cos(par.phi0);
0196                 }
0197
0198                 par.es = 0.;
0199             }
0200
0201     }} // namespace detail::gnom
0202     #endif // doxygen
0203
0204     /*!
0205         \brief Gnomonic projection
0206         \ingroup projections
0207         \tparam Geographic latlong point type
0208         \tparam Cartesian xy point type
0209         \tparam Parameters parameter type
0210         \par Projection characteristics
0211          - Azimuthal
0212          - Spheroid
0213         \par Example
0214         \image html ex_gnom.gif
0215     */
0216     template <typename T, typename Parameters>
0217     struct gnom_spheroid : public detail::gnom::base_gnom_spheroid<T, Parameters>
0218     {
0219         template <typename Params>
0220         inline gnom_spheroid(Params const& , Parameters & par)
0221         {
0222             detail::gnom::setup_gnom(par, this->m_proj_parm);
0223         }
0224     };
0225
0226     #ifndef DOXYGEN_NO_DETAIL
0227     namespace detail
0228     {
0229
0230         // Static projection
0231         BOOST_GEOMETRY_PROJECTIONS_DETAIL_STATIC_PROJECTION_FI(srs::spar::proj_gnom, gnom_spheroid)
0232
0233         // Factory entry(s)
0234         BOOST_GEOMETRY_PROJECTIONS_DETAIL_FACTORY_ENTRY_FI(gnom_entry, gnom_spheroid)
0235
0236         BOOST_GEOMETRY_PROJECTIONS_DETAIL_FACTORY_INIT_BEGIN(gnom_init)
0237         {
0238             BOOST_GEOMETRY_PROJECTIONS_DETAIL_FACTORY_INIT_ENTRY(gnom, gnom_entry);
0239         }
0240
0241     } // namespace detail
0242     #endif // doxygen
0243
0244 } // namespace projections
0245
0246 }} // namespace boost::geometry
0247
0248 #endif // BOOST_GEOMETRY_PROJECTIONS_GNOM_HPP
0249