ceph/src/boost/boost/geometry/arithmetic/determinant.hpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2
   3 // Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
   4 // Copyright (c) 2008-2012 Barend Gehrels, Amsterdam, the Netherlands.
   5 // Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
   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_ARITHMETIC_DETERMINANT_HPP
  12 #define BOOST_GEOMETRY_ARITHMETIC_DETERMINANT_HPP
  13
  14
  15 #include <cstddef>
  16
  17 #include <boost/geometry/core/access.hpp>
  18 #include <boost/geometry/geometries/concepts/point_concept.hpp>
  19 #include <boost/geometry/util/select_coordinate_type.hpp>
  20
  21 #include <boost/numeric/conversion/cast.hpp>
  22
  23 namespace boost { namespace geometry
  24 {
  25
  26 #ifndef DOXYGEN_NO_DETAIL
  27 namespace detail
  28 {
  29
  30 template <typename ReturnType, typename U, typename V>
  31 class calculate_determinant
  32 {
  33     template <typename T>
  34     static inline ReturnType rt(T const& v)
  35     {
  36         return boost::numeric_cast<ReturnType>(v);
  37     }
  38
  39 public :
  40
  41     static inline ReturnType apply(U const& ux, U const& uy
  42                                  , V const& vx, V const& vy)
  43     {
  44         return rt(ux) * rt(vy) - rt(uy) * rt(vx);
  45     }
  46 };
  47
  48 template <typename ReturnType, typename U, typename V>
  49 inline ReturnType determinant(U const& ux, U const& uy
  50                             , V const& vx, V const& vy)
  51 {
  52     return calculate_determinant
  53         <
  54             ReturnType, U, V
  55         >::apply(ux, uy, vx, vy);
  56 }
  57
  58
  59 template <typename ReturnType, typename U, typename V>
  60 inline ReturnType determinant(U const& u, V const& v)
  61 {
  62     BOOST_CONCEPT_ASSERT( (concepts::ConstPoint<U>) );
  63     BOOST_CONCEPT_ASSERT( (concepts::ConstPoint<V>) );
  64
  65     return calculate_determinant
  66         <
  67             ReturnType,
  68             typename geometry::coordinate_type<U>::type,
  69             typename geometry::coordinate_type<V>::type
  70         >::apply(get<0>(u), get<1>(u), get<0>(v), get<1>(v));
  71 }
  72
  73 } // namespace detail
  74 #endif // DOXYGEN_NO_DETAIL
  75
  76 }} // namespace boost::geometry
  77
  78 #endif // BOOST_GEOMETRY_ARITHMETIC_DETERMINANT_HPP