projections/proj/eck4.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_ECK4_HPP
0041 #define BOOST_GEOMETRY_PROJECTIONS_ECK4_HPP
0042
0043 #include <boost/geometry/srs/projections/impl/base_static.hpp>
0044 #include <boost/geometry/srs/projections/impl/base_dynamic.hpp>
0045 #include <boost/geometry/srs/projections/impl/projects.hpp>
0046 #include <boost/geometry/srs/projections/impl/factory_entry.hpp>
0047 #include <boost/geometry/srs/projections/impl/aasincos.hpp>
0048
0049 namespace boost { namespace geometry
0050 {
0051
0052 namespace projections
0053 {
0054     #ifndef DOXYGEN_NO_DETAIL
0055     namespace detail { namespace eck4
0056     {
0057
0058             static const double C_x = .42223820031577120149;
0059             static const double C_y = 1.32650042817700232218;
0060             static const double RC_y = .75386330736002178205;
0061             static const double C_p = 3.57079632679489661922;
0062             static const double RC_p = .28004957675577868795;
0063             static const double epsilon = 1e-7;
0064             static const int n_iter = 6;
0065
0066             template <typename T, typename Parameters>
0067             struct base_eck4_spheroid
0068             {
0069                 // FORWARD(s_forward)  spheroid
0070                 // Project coordinates from geographic (lon, lat) to cartesian (x, y)
0071                 inline void fwd(Parameters const& , T const& lp_lon, T lp_lat, T& xy_x, T& xy_y) const
0072                 {
0073                     T p, V, s, c;
0074                     int i;
0075
0076                     p = C_p * sin(lp_lat);
0077                     V = lp_lat * lp_lat;
0078                     lp_lat *= 0.895168 + V * ( 0.0218849 + V * 0.00826809 );
0079                     for (i = n_iter; i ; --i) {
0080                         c = cos(lp_lat);
0081                         s = sin(lp_lat);
0082                         lp_lat -= V = (lp_lat + s * (c + 2.) - p) /
0083                             (1. + c * (c + 2.) - s * s);
0084                         if (fabs(V) < epsilon)
0085                             break;
0086                     }
0087                     if (!i) {
0088                         xy_x = C_x * lp_lon;
0089                         xy_y = lp_lat < 0. ? -C_y : C_y;
0090                     } else {
0091                         xy_x = C_x * lp_lon * (1. + cos(lp_lat));
0092                         xy_y = C_y * sin(lp_lat);
0093                     }
0094                 }
0095
0096                 // INVERSE(s_inverse)  spheroid
0097                 // Project coordinates from cartesian (x, y) to geographic (lon, lat)
0098                 inline void inv(Parameters const& , T const& xy_x, T const& xy_y, T& lp_lon, T& lp_lat) const
0099                 {
0100                     T c;
0101
0102                     lp_lat = aasin(xy_y * RC_y);
0103                     lp_lon = xy_x / (C_x * (1. + (c = cos(lp_lat))));
0104                     lp_lat = aasin((lp_lat + sin(lp_lat) * (c + 2.)) * RC_p);
0105                 }
0106
0107                 static inline std::string get_name()
0108                 {
0109                     return "eck4_spheroid";
0110                 }
0111
0112             };
0113
0114             // Eckert IV
0115             template <typename Parameters>
0116             inline void setup_eck4(Parameters& par)
0117             {
0118                 par.es = 0.;
0119             }
0120
0121     }} // namespace detail::eck4
0122     #endif // doxygen
0123
0124     /*!
0125         \brief Eckert IV projection
0126         \ingroup projections
0127         \tparam Geographic latlong point type
0128         \tparam Cartesian xy point type
0129         \tparam Parameters parameter type
0130         \par Projection characteristics
0131          - Pseudocylindrical
0132          - Spheroid
0133         \par Example
0134         \image html ex_eck4.gif
0135     */
0136     template <typename T, typename Parameters>
0137     struct eck4_spheroid : public detail::eck4::base_eck4_spheroid<T, Parameters>
0138     {
0139         template <typename Params>
0140         inline eck4_spheroid(Params const& , Parameters & par)
0141         {
0142             detail::eck4::setup_eck4(par);
0143         }
0144     };
0145
0146     #ifndef DOXYGEN_NO_DETAIL
0147     namespace detail
0148     {
0149
0150         // Static projection
0151         BOOST_GEOMETRY_PROJECTIONS_DETAIL_STATIC_PROJECTION_FI(srs::spar::proj_eck4, eck4_spheroid)
0152
0153         // Factory entry(s)
0154         BOOST_GEOMETRY_PROJECTIONS_DETAIL_FACTORY_ENTRY_FI(eck4_entry, eck4_spheroid)
0155
0156         BOOST_GEOMETRY_PROJECTIONS_DETAIL_FACTORY_INIT_BEGIN(eck4_init)
0157         {
0158             BOOST_GEOMETRY_PROJECTIONS_DETAIL_FACTORY_INIT_ENTRY(eck4, eck4_entry);
0159         }
0160
0161     } // namespace detail
0162     #endif // doxygen
0163
0164 } // namespace projections
0165
0166 }} // namespace boost::geometry
0167
0168 #endif // BOOST_GEOMETRY_PROJECTIONS_ECK4_HPP
0169