ceph/src/boost/boost/geometry/srs/projections/impl/pj_auth.hpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2 // This file is manually converted from PROJ4
   3
   4 // Copyright (c) 2008-2012 Barend Gehrels, Amsterdam, the Netherlands.
   5
   6 // This file was modified by Oracle on 2017, 2018.
   7 // Modifications copyright (c) 2017-2018, Oracle and/or its affiliates.
   8 // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
   9
  10 // Use, modification and distribution is subject to the Boost Software License,
  11 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  12 // http://www.boost.org/LICENSE_1_0.txt)
  13
  14 // This file is converted from PROJ4, http://trac.osgeo.org/proj
  15 // PROJ4 is originally written by Gerald Evenden (then of the USGS)
  16 // PROJ4 is maintained by Frank Warmerdam
  17 // PROJ4 is converted to Geometry Library by Barend Gehrels (Geodan, Amsterdam)
  18
  19 // Original copyright notice:
  20
  21 // Permission is hereby granted, free of charge, to any person obtaining a
  22 // copy of this software and associated documentation files (the "Software"),
  23 // to deal in the Software without restriction, including without limitation
  24 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
  25 // and/or sell copies of the Software, and to permit persons to whom the
  26 // Software is furnished to do so, subject to the following conditions:
  27
  28 // The above copyright notice and this permission notice shall be included
  29 // in all copies or substantial portions of the Software.
  30
  31 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  32 // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  33 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  34 // THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  35 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  36 // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  37 // DEALINGS IN THE SOFTWARE.
  38
  39 #ifndef BOOST_GEOMETRY_PROJECTIONS_IMPL_PJ_AUTH_HPP
  40 #define BOOST_GEOMETRY_PROJECTIONS_IMPL_PJ_AUTH_HPP
  41
  42 #include <cassert>
  43 #include <cmath>
  44
  45 #include <boost/geometry/core/assert.hpp>
  46
  47 namespace boost { namespace geometry { namespace projections {
  48
  49 namespace detail {
  50
  51 template <typename T>
  52 struct apa
  53 {
  54     static const std::size_t size = 3;
  55
  56     T const& operator[](size_t i) const { return data[i]; }
  57     T & operator[](size_t i) { return data[i]; }
  58
  59 private:
  60     T data[3];
  61 };
  62
  63 /* determine latitude from authalic latitude */
  64 template <typename T>
  65 inline detail::apa<T> pj_authset(T const& es)
  66 {
  67     static const T P00 = .33333333333333333333;
  68     static const T P01 = .17222222222222222222;
  69     static const T P02 = .10257936507936507936;
  70     static const T P10 = .06388888888888888888;
  71     static const T P11 = .06640211640211640211;
  72     static const T P20 = .01641501294219154443;
  73
  74     T t = 0;
  75     detail::apa<T> apa;
  76
  77     {
  78         apa[0] = es * P00;
  79         t = es * es;
  80         apa[0] += t * P01;
  81         apa[1] = t * P10;
  82         t *= es;
  83         apa[0] += t * P02;
  84         apa[1] += t * P11;
  85         apa[2] = t * P20;
  86     }
  87
  88     return apa;
  89 }
  90
  91 template <typename T>
  92 inline T pj_authlat(T const& beta, detail::apa<T> const& apa)
  93 {
  94     T const t = beta + beta;
  95
  96     return(beta + apa[0] * sin(t) + apa[1] * sin(t + t) + apa[2] * sin(t + t + t));
  97 }
  98
  99 } // namespace detail
 100 }}} // namespace boost::geometry::projections
 101
 102 #endif // BOOST_GEOMETRY_PROJECTIONS_IMPL_PJ_AUTH_HPP