ceph/src/boost/boost/geometry/srs/projections/impl/pj_phi2.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.
   7 // Modifications copyright (c) 2017, 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_PHI2_HPP
  40 #define BOOST_GEOMETRY_PROJECTIONS_PHI2_HPP
  41
  42 #include <boost/geometry/util/math.hpp>
  43
  44 namespace boost { namespace geometry { namespace projections {
  45 namespace detail {
  46
  47 template <typename T>
  48 inline T pj_phi2(T const& ts, T const& e)
  49 {
  50     static const T TOL = 1.0e-10;
  51     static const int N_ITER = 15;
  52
  53     T eccnth, Phi, con, dphi;
  54     int i;
  55
  56     eccnth = .5 * e;
  57     Phi = geometry::math::half_pi<T>() - 2. * atan (ts);
  58     i = N_ITER;
  59     do {
  60         con = e * sin (Phi);
  61         dphi = geometry::math::half_pi<T>() - 2. * atan (ts * pow((1. - con) /
  62            (1. + con), eccnth)) - Phi;
  63         Phi += dphi;
  64     } while ( geometry::math::abs(dphi) > TOL && --i);
  65     if (i <= 0)
  66         BOOST_THROW_EXCEPTION( projection_exception(-18) );
  67     return Phi;
  68 }
  69
  70 } // namespace detail
  71 }}} // namespace boost::geometry::projections
  72
  73 #endif