ceph/src/boost/libs/geometry/include/boost/geometry/algorithms/detail/flattening.hpp

   1 // Boost.Geometry
   2
   3 // Copyright (c) 2014 Oracle and/or its affiliates.
   4
   5 // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
   6
   7 // Use, modification and distribution is subject to the Boost Software License,
   8 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   9 // http://www.boost.org/LICENSE_1_0.txt)
  10
  11 #ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_FLATTENING_HPP
  12 #define BOOST_GEOMETRY_ALGORITHMS_DETAIL_FLATTENING_HPP
  13
  14 #include <boost/geometry/core/radius.hpp>
  15 #include <boost/geometry/core/tag.hpp>
  16 #include <boost/geometry/core/tags.hpp>
  17
  18 #include <boost/geometry/algorithms/not_implemented.hpp>
  19
  20 namespace boost { namespace geometry
  21 {
  22
  23 #ifndef DOXYGEN_NO_DISPATCH
  24 namespace detail_dispatch
  25 {
  26
  27 template <typename ResultType, typename Geometry, typename Tag = typename tag<Geometry>::type>
  28 struct flattening
  29     : not_implemented<Tag>
  30 {};
  31
  32 template <typename ResultType, typename Geometry>
  33 struct flattening<ResultType, Geometry, srs_sphere_tag>
  34 {
  35     static inline ResultType apply(Geometry const& /*geometry*/)
  36     {
  37         return ResultType(0);
  38     }
  39 };
  40
  41 template <typename ResultType, typename Geometry>
  42 struct flattening<ResultType, Geometry, srs_spheroid_tag>
  43 {
  44     static inline ResultType apply(Geometry const& geometry)
  45     {
  46         return ResultType(get_radius<0>(geometry) - get_radius<2>(geometry))
  47                     / ResultType(get_radius<0>(geometry));
  48     }
  49 };
  50
  51 } // namespace detail_dispatch
  52 #endif // DOXYGEN_NO_DISPATCH
  53
  54 #ifndef DOXYGEN_NO_DETAIL
  55 namespace detail
  56 {
  57
  58 template <typename ResultType, typename Geometry>
  59 ResultType flattening(Geometry const& geometry)
  60 {
  61     return detail_dispatch::flattening<ResultType, Geometry>::apply(geometry);
  62 }
  63
  64 } // namespace detail
  65 #endif // DOXYGEN_NO_DETAIL
  66
  67 }} // namespace boost::geometry
  68
  69 #endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_FLATTENING_HPP