1 // Boost.Geometry
2
3 // Copyright (c) 2015-2020, 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 <algorithm>
15 #include <cstddef>
16 #include <type_traits>
17
18 #include <boost/geometry/core/access.hpp>
19 #include <boost/geometry/core/coordinate_dimension.hpp>
20 #include <boost/geometry/core/coordinate_type.hpp>
21
22 #include <boost/geometry/util/math.hpp>
23
24 #include <boost/geometry/views/detail/indexed_point_view.hpp>
25
26 namespace boost { namespace geometry
27 {
28
29 #ifndef DOXYGEN_NO_DETAIL
30 namespace detail { namespace expand
31 {
32
33 template
34 <
35 typename Point,
36 template <typename> class PlusOrMinus,
37 std::size_t I = 0,
38 std::size_t D = dimension<Point>::value
39 >
40 struct corner_by_epsilon
41 {
applyboost::geometry::detail::expand::corner_by_epsilon42 static inline void apply(Point & point)
43 {
44 typedef typename coordinate_type<Point>::type coord_type;
45 coord_type const coord = get<I>(point);
46 coord_type const seps = math::scaled_epsilon(coord);
47
48 set<I>(point, PlusOrMinus<coord_type>()(coord, seps));
49
50 corner_by_epsilon<Point, PlusOrMinus, I+1>::apply(point);
51 }
52
applyboost::geometry::detail::expand::corner_by_epsilon53 static inline void apply(Point & point,
54 typename coordinate_type<Point>::type const& eps)
55 {
56 typedef typename coordinate_type<Point>::type coord_type;
57 coord_type const coord = get<I>(point);
58 coord_type const seps = math::scaled_epsilon(coord, eps);
59
60 set<I>(point, PlusOrMinus<coord_type>()(coord, seps));
61
62 corner_by_epsilon<Point, PlusOrMinus, I + 1>::apply(point);
63 }
64 };
65
66 template
67 <
68 typename Point,
69 template <typename> class PlusOrMinus,
70 std::size_t D
71 >
72 struct corner_by_epsilon<Point, PlusOrMinus, D, D>
73 {
applyboost::geometry::detail::expand::corner_by_epsilon74 static inline void apply(Point const&) {}
applyboost::geometry::detail::expand::corner_by_epsilon75 static inline void apply(Point const&, typename coordinate_type<Point>::type const&) {}
76 };
77
78 template
79 <
80 typename Box,
81 bool Enable = ! std::is_integral<typename coordinate_type<Box>::type>::value
82 >
83 struct expand_by_epsilon
84 {
applyboost::geometry::detail::expand::expand_by_epsilon85 static inline void apply(Box & box)
86 {
87 typedef detail::indexed_point_view<Box, min_corner> min_type;
88 min_type min_point(box);
89 corner_by_epsilon<min_type, std::minus>::apply(min_point);
90
91 typedef detail::indexed_point_view<Box, max_corner> max_type;
92 max_type max_point(box);
93 corner_by_epsilon<max_type, std::plus>::apply(max_point);
94 }
95
applyboost::geometry::detail::expand::expand_by_epsilon96 static inline void apply(Box & box,
97 typename coordinate_type<Box>::type const& eps)
98 {
99 typedef detail::indexed_point_view<Box, min_corner> min_type;
100 min_type min_point(box);
101 corner_by_epsilon<min_type, std::minus>::apply(min_point, eps);
102
103 typedef detail::indexed_point_view<Box, max_corner> max_type;
104 max_type max_point(box);
105 corner_by_epsilon<max_type, std::plus>::apply(max_point, eps);
106 }
107 };
108
109 template <typename Box>
110 struct expand_by_epsilon<Box, false>
111 {
applyboost::geometry::detail::expand::expand_by_epsilon112 static inline void apply(Box &) {}
applyboost::geometry::detail::expand::expand_by_epsilon113 static inline void apply(Box &, typename coordinate_type<Box>::type const&) {}
114 };
115
116 } // namespace expand
117
118 template <typename Box>
expand_by_epsilon(Box & box)119 inline void expand_by_epsilon(Box & box)
120 {
121 expand::expand_by_epsilon<Box>::apply(box);
122 }
123
124 template <typename Box>
expand_by_epsilon(Box & box,typename coordinate_type<Box>::type const & eps)125 inline void expand_by_epsilon(Box & box,
126 typename coordinate_type<Box>::type const& eps)
127 {
128 expand::expand_by_epsilon<Box>::apply(box, eps);
129 }
130
131 } // namespace detail
132 #endif // DOXYGEN_NO_DETAIL
133
134 }} // namespace boost::geometry
135
136 #endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_EXPAND_EXPAND_BY_EPSILON_HPP
137