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

   1 // Boost.Geometry
   2
   3 // Copyright (c) 2015, Oracle and/or its affiliates.
   4
   5 // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
   6
   7 // Distributed under the Boost Software License, Version 1.0.
   8 // (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_EXPAND_EXPAND_BY_EPSILON_HPP
  12 #define BOOST_GEOMETRY_ALGORITHMS_DETAIL_EXPAND_EXPAND_BY_EPSILON_HPP
  13
  14 #include <cstddef>
  15 #include <algorithm>
  16
  17 #include <boost/type_traits/is_floating_point.hpp>
  18
  19 #include <boost/geometry/core/access.hpp>
  20 #include <boost/geometry/core/coordinate_dimension.hpp>
  21 #include <boost/geometry/core/coordinate_type.hpp>
  22
  23 #include <boost/geometry/util/math.hpp>
  24
  25 #include <boost/geometry/views/detail/indexed_point_view.hpp>
  26
  27 namespace boost { namespace geometry
  28 {
  29
  30 #ifndef DOXYGEN_NO_DETAIL
  31 namespace detail { namespace expand
  32 {
  33
  34 template
  35 <
  36     typename Point,
  37     template <typename> class PlusOrMinus,
  38     std::size_t I = 0,
  39     std::size_t D = dimension<Point>::value,
  40     bool Enable = boost::is_floating_point
  41                     <
  42                         typename coordinate_type<Point>::type
  43                     >::value
  44 >
  45 struct corner_by_epsilon
  46 {
  47     static inline void apply(Point & point)
  48     {
  49         typedef typename coordinate_type<Point>::type coord_type;
  50         coord_type const coord = get<I>(point);
  51         coord_type const eps = math::scaled_epsilon(coord);
  52
  53         set<I>(point, PlusOrMinus<coord_type>()(coord, eps));
  54
  55         corner_by_epsilon<Point, PlusOrMinus, I+1>::apply(point);
  56     }
  57 };
  58
  59 template
  60 <
  61     typename Point,
  62     template <typename> class PlusOrMinus,
  63     std::size_t I,
  64     std::size_t D
  65 >
  66 struct corner_by_epsilon<Point, PlusOrMinus, I, D, false>
  67 {
  68     static inline void apply(Point const&) {}
  69 };
  70
  71 template
  72 <
  73     typename Point,
  74     template <typename> class PlusOrMinus,
  75     std::size_t D,
  76     bool Enable
  77 >
  78 struct corner_by_epsilon<Point, PlusOrMinus, D, D, Enable>
  79 {
  80     static inline void apply(Point const&) {}
  81 };
  82
  83 template
  84 <
  85     typename Point,
  86     template <typename> class PlusOrMinus,
  87     std::size_t D
  88 >
  89 struct corner_by_epsilon<Point, PlusOrMinus, D, D, false>
  90 {
  91     static inline void apply(Point const&) {}
  92 };
  93
  94 } // namespace expand
  95
  96 template <typename Box>
  97 inline void expand_by_epsilon(Box & box)
  98 {
  99     typedef detail::indexed_point_view<Box, min_corner> min_type;
 100     min_type min_point(box);
 101     expand::corner_by_epsilon<min_type, std::minus>::apply(min_point);
 102
 103     typedef detail::indexed_point_view<Box, max_corner> max_type;
 104     max_type max_point(box);
 105     expand::corner_by_epsilon<max_type, std::plus>::apply(max_point);
 106 }
 107
 108 } // namespace detail
 109 #endif // DOXYGEN_NO_DETAIL
 110
 111 }} // namespace boost::geometry
 112
 113 #endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_EXPAND_EXPAND_BY_EPSILON_HPP