projections/proj/eck2.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_ECK2_HPP
0041 #define BOOST_GEOMETRY_PROJECTIONS_ECK2_HPP
0042
0043 #include <boost/geometry/util/math.hpp>
0044
0045 #include <boost/geometry/srs/projections/impl/base_static.hpp>
0046 #include <boost/geometry/srs/projections/impl/base_dynamic.hpp>
0047 #include <boost/geometry/srs/projections/impl/projects.hpp>
0048 #include <boost/geometry/srs/projections/impl/factory_entry.hpp>
0049
0050 namespace boost { namespace geometry
0051 {
0052
0053 namespace projections
0054 {
0055     #ifndef DOXYGEN_NO_DETAIL
0056     namespace detail { namespace eck2
0057     {
0058
0059             static const double FXC = 0.46065886596178063902;
0060             static const double FYC = 1.44720250911653531871;
0061             //static const double C13 = 0.33333333333333333333;
0062             static const double one_plus_eps = 1.0000001;
0063
0064             template <typename T, typename Parameters>
0065             struct base_eck2_spheroid
0066             {
0067                 // FORWARD(s_forward)  spheroid
0068                 // Project coordinates from geographic (lon, lat) to cartesian (x, y)
0069                 inline void fwd(Parameters const& , T const& lp_lon, T const& lp_lat, T& xy_x, T& xy_y) const
0070                 {
0071                     xy_x = FXC * lp_lon * (xy_y = sqrt(4. - 3. * sin(fabs(lp_lat))));
0072                     xy_y = FYC * (2. - xy_y);
0073                     if ( lp_lat < 0.) xy_y = -xy_y;
0074                 }
0075
0076                 // INVERSE(s_inverse)  spheroid
0077                 // Project coordinates from cartesian (x, y) to geographic (lon, lat)
0078                 inline void inv(Parameters const& , T const& xy_x, T const& xy_y, T& lp_lon, T& lp_lat) const
0079                 {
0080                     static const T half_pi = detail::half_pi<T>();
0081                     static const T C13 = detail::third<T>();
0082
0083                     lp_lon = xy_x / (FXC * ( lp_lat = 2. - fabs(xy_y) / FYC) );
0084                     lp_lat = (4. - lp_lat * lp_lat) * C13;
0085                     if (fabs(lp_lat) >= 1.) {
0086                         if (fabs(lp_lat) > one_plus_eps)
0087                             BOOST_THROW_EXCEPTION( projection_exception(error_tolerance_condition) );
0088                         else
0089                             lp_lat = lp_lat < 0. ? -half_pi : half_pi;
0090                     } else
0091                         lp_lat = asin(lp_lat);
0092                     if (xy_y < 0)
0093                         lp_lat = -lp_lat;
0094                 }
0095
0096                 static inline std::string get_name()
0097                 {
0098                     return "eck2_spheroid";
0099                 }
0100
0101             };
0102
0103             // Eckert II
0104             template <typename Parameters>
0105             inline void setup_eck2(Parameters& par)
0106             {
0107                 par.es = 0.;
0108             }
0109
0110     }} // namespace detail::eck2
0111     #endif // doxygen
0112
0113     /*!
0114         \brief Eckert II projection
0115         \ingroup projections
0116         \tparam Geographic latlong point type
0117         \tparam Cartesian xy point type
0118         \tparam Parameters parameter type
0119         \par Projection characteristics
0120          - Pseudocylindrical
0121          - Spheroid
0122         \par Example
0123         \image html ex_eck2.gif
0124     */
0125     template <typename T, typename Parameters>
0126     struct eck2_spheroid : public detail::eck2::base_eck2_spheroid<T, Parameters>
0127     {
0128         template <typename Params>
0129         inline eck2_spheroid(Params const& , Parameters & par)
0130         {
0131             detail::eck2::setup_eck2(par);
0132         }
0133     };
0134
0135     #ifndef DOXYGEN_NO_DETAIL
0136     namespace detail
0137     {
0138
0139         // Static projection
0140         BOOST_GEOMETRY_PROJECTIONS_DETAIL_STATIC_PROJECTION_FI(srs::spar::proj_eck2, eck2_spheroid)
0141
0142         // Factory entry(s)
0143         BOOST_GEOMETRY_PROJECTIONS_DETAIL_FACTORY_ENTRY_FI(eck2_entry, eck2_spheroid)
0144
0145         BOOST_GEOMETRY_PROJECTIONS_DETAIL_FACTORY_INIT_BEGIN(eck2_init)
0146         {
0147             BOOST_GEOMETRY_PROJECTIONS_DETAIL_FACTORY_INIT_ENTRY(eck2, eck2_entry);
0148         }
0149
0150     } // namespace detail
0151     #endif // doxygen
0152
0153 } // namespace projections
0154
0155 }} // namespace boost::geometry
0156
0157 #endif // BOOST_GEOMETRY_PROJECTIONS_ECK2_HPP
0158