projections/proj/airy.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 // Purpose:  Implementation of the airy (Airy) projection.
0023 // Author:   Gerald Evenden (1995)
0024 //           Thomas Knudsen (2016) - revise/add regression tests
0025 // Copyright (c) 1995, Gerald Evenden
0026
0027 // Permission is hereby granted, free of charge, to any person obtaining a
0028 // copy of this software and associated documentation files (the "Software"),
0029 // to deal in the Software without restriction, including without limitation
0030 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
0031 // and/or sell copies of the Software, and to permit persons to whom the
0032 // Software is furnished to do so, subject to the following conditions:
0033
0034 // The above copyright notice and this permission notice shall be included
0035 // in all copies or substantial portions of the Software.
0036
0037 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
0038 // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
0039 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
0040 // THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
0041 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
0042 // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
0043 // DEALINGS IN THE SOFTWARE.
0044
0045 #ifndef BOOST_GEOMETRY_PROJECTIONS_AIRY_HPP
0046 #define BOOST_GEOMETRY_PROJECTIONS_AIRY_HPP
0047
0048 #include <boost/geometry/srs/projections/impl/base_static.hpp>
0049 #include <boost/geometry/srs/projections/impl/base_dynamic.hpp>
0050 #include <boost/geometry/srs/projections/impl/factory_entry.hpp>
0051 #include <boost/geometry/srs/projections/impl/pj_param.hpp>
0052 #include <boost/geometry/srs/projections/impl/projects.hpp>
0053
0054 #include <boost/geometry/util/math.hpp>
0055
0056 namespace boost { namespace geometry
0057 {
0058
0059 namespace projections
0060 {
0061     #ifndef DOXYGEN_NO_DETAIL
0062     namespace detail { namespace airy
0063     {
0064
0065             static const double epsilon = 1.e-10;
0066             enum mode_type {
0067                 n_pole = 0,
0068                 s_pole = 1,
0069                 equit  = 2,
0070                 obliq  = 3
0071             };
0072
0073             template <typename T>
0074             struct par_airy
0075             {
0076                 T    p_halfpi;
0077                 T    sinph0;
0078                 T    cosph0;
0079                 T    Cb;
0080                 mode_type mode;
0081                 bool no_cut;    /* do not cut at hemisphere limit */
0082             };
0083
0084             template <typename T, typename Parameters>
0085             struct base_airy_spheroid
0086             {
0087                 par_airy<T> m_proj_parm;
0088
0089                 // FORWARD(s_forward)  spheroid
0090                 // Project coordinates from geographic (lon, lat) to cartesian (x, y)
0091                 inline void fwd(Parameters const& , T const& lp_lon, T lp_lat, T& xy_x, T& xy_y) const
0092                 {
0093                     static const T half_pi = detail::half_pi<T>();
0094
0095                     T  sinlam, coslam, cosphi, sinphi, t, s, Krho, cosz;
0096
0097                     sinlam = sin(lp_lon);
0098                     coslam = cos(lp_lon);
0099                     switch (this->m_proj_parm.mode) {
0100                     case equit:
0101                     case obliq:
0102                         sinphi = sin(lp_lat);
0103                         cosphi = cos(lp_lat);
0104                         cosz = cosphi * coslam;
0105                         if (this->m_proj_parm.mode == obliq)
0106                             cosz = this->m_proj_parm.sinph0 * sinphi + this->m_proj_parm.cosph0 * cosz;
0107                         if (!this->m_proj_parm.no_cut && cosz < -epsilon) {
0108                             BOOST_THROW_EXCEPTION( projection_exception(error_tolerance_condition) );
0109                         }
0110                         if (fabs(s = 1. - cosz) > epsilon) {
0111                             t = 0.5 * (1. + cosz);
0112                             Krho = -log(t)/s - this->m_proj_parm.Cb / t;
0113                         } else
0114                             Krho = 0.5 - this->m_proj_parm.Cb;
0115                         xy_x = Krho * cosphi * sinlam;
0116                         if (this->m_proj_parm.mode == obliq)
0117                             xy_y = Krho * (this->m_proj_parm.cosph0 * sinphi -
0118                                 this->m_proj_parm.sinph0 * cosphi * coslam);
0119                         else
0120                             xy_y = Krho * sinphi;
0121                         break;
0122                     case s_pole:
0123                     case n_pole:
0124                         lp_lat = fabs(this->m_proj_parm.p_halfpi - lp_lat);
0125                         if (!this->m_proj_parm.no_cut && (lp_lat - epsilon) > half_pi)
0126                             BOOST_THROW_EXCEPTION( projection_exception(error_tolerance_condition) );
0127                         if ((lp_lat *= 0.5) > epsilon) {
0128                             t = tan(lp_lat);
0129                             Krho = -2.*(log(cos(lp_lat)) / t + t * this->m_proj_parm.Cb);
0130                             xy_x = Krho * sinlam;
0131                             xy_y = Krho * coslam;
0132                             if (this->m_proj_parm.mode == n_pole)
0133                                 xy_y = -xy_y;
0134                         } else
0135                             xy_x = xy_y = 0.;
0136                     }
0137                 }
0138
0139                 static inline std::string get_name()
0140                 {
0141                     return "airy_spheroid";
0142                 }
0143
0144             };
0145
0146             // Airy
0147             template <typename Params, typename Parameters, typename T>
0148             inline void setup_airy(Params const& params, Parameters& par, par_airy<T>& proj_parm)
0149             {
0150                 static const T half_pi = detail::half_pi<T>();
0151
0152                 T beta;
0153
0154                 proj_parm.no_cut = pj_get_param_b<srs::spar::no_cut>(params, "no_cut", srs::dpar::no_cut);
0155                 beta = 0.5 * (half_pi - pj_get_param_r<T, srs::spar::lat_b>(params, "lat_b", srs::dpar::lat_b));
0156                 if (fabs(beta) < epsilon)
0157                     proj_parm.Cb = -0.5;
0158                 else {
0159                     proj_parm.Cb = 1./tan(beta);
0160                     proj_parm.Cb *= proj_parm.Cb * log(cos(beta));
0161                 }
0162
0163                 if (fabs(fabs(par.phi0) - half_pi) < epsilon)
0164                     if (par.phi0 < 0.) {
0165                         proj_parm.p_halfpi = -half_pi;
0166                         proj_parm.mode = s_pole;
0167                     } else {
0168                         proj_parm.p_halfpi =  half_pi;
0169                         proj_parm.mode = n_pole;
0170                     }
0171                 else {
0172                     if (fabs(par.phi0) < epsilon)
0173                         proj_parm.mode = equit;
0174                     else {
0175                         proj_parm.mode = obliq;
0176                         proj_parm.sinph0 = sin(par.phi0);
0177                         proj_parm.cosph0 = cos(par.phi0);
0178                     }
0179                 }
0180                 par.es = 0.;
0181             }
0182
0183     }} // namespace detail::airy
0184     #endif // doxygen
0185
0186     /*!
0187         \brief Airy projection
0188         \ingroup projections
0189         \tparam Geographic latlong point type
0190         \tparam Cartesian xy point type
0191         \tparam Parameters parameter type
0192         \par Projection characteristics
0193          - Miscellaneous
0194          - Spheroid
0195          - no inverse
0196         \par Projection parameters
0197          - no_cut: Do not cut at hemisphere limit (boolean)
0198          - lat_b (degrees)
0199         \par Example
0200         \image html ex_airy.gif
0201     */
0202     template <typename T, typename Parameters>
0203     struct airy_spheroid : public detail::airy::base_airy_spheroid<T, Parameters>
0204     {
0205         template <typename Params>
0206         inline airy_spheroid(Params const& params, Parameters & par)
0207         {
0208             detail::airy::setup_airy(params, par, this->m_proj_parm);
0209         }
0210     };
0211
0212     #ifndef DOXYGEN_NO_DETAIL
0213     namespace detail
0214     {
0215
0216         // Static projection
0217         BOOST_GEOMETRY_PROJECTIONS_DETAIL_STATIC_PROJECTION_F(srs::spar::proj_airy, airy_spheroid)
0218
0219         // Factory entry(s)
0220         BOOST_GEOMETRY_PROJECTIONS_DETAIL_FACTORY_ENTRY_F(airy_entry, airy_spheroid)
0221
0222         BOOST_GEOMETRY_PROJECTIONS_DETAIL_FACTORY_INIT_BEGIN(airy_init)
0223         {
0224             BOOST_GEOMETRY_PROJECTIONS_DETAIL_FACTORY_INIT_ENTRY(airy, airy_entry)
0225         }
0226
0227     } // namespace detail
0228     #endif // doxygen
0229
0230 } // namespace projections
0231
0232 }} // namespace boost::geometry
0233
0234 #endif // BOOST_GEOMETRY_PROJECTIONS_AIRY_HPP
0235