]>
Commit | Line | Data |
---|---|---|
7c673cae FG |
1 | // Boost.Geometry (aka GGL, Generic Geometry Library) |
2 | ||
20effc67 | 3 | // Copyright (c) 2014-2020, Oracle and/or its affiliates. |
7c673cae FG |
4 | |
5 | // Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle | |
20effc67 | 6 | // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle |
7c673cae FG |
7 | |
8 | // Licensed under the Boost Software License version 1.0. | |
9 | // http://www.boost.org/users/license.html | |
10 | ||
11 | #ifndef BOOST_GEOMETRY_ALGORITHMS_NUM_SEGMENTS_HPP | |
12 | #define BOOST_GEOMETRY_ALGORITHMS_NUM_SEGMENTS_HPP | |
13 | ||
14 | #include <cstddef> | |
15 | ||
20effc67 TL |
16 | #include <boost/range/size.hpp> |
17 | #include <boost/range/value_type.hpp> | |
7c673cae FG |
18 | |
19 | #include <boost/variant/apply_visitor.hpp> | |
20 | #include <boost/variant/static_visitor.hpp> | |
21 | #include <boost/variant/variant_fwd.hpp> | |
22 | ||
23 | #include <boost/geometry/core/closure.hpp> | |
24 | #include <boost/geometry/core/tag.hpp> | |
25 | #include <boost/geometry/core/tags.hpp> | |
26 | ||
27 | #include <boost/geometry/util/range.hpp> | |
28 | ||
29 | #include <boost/geometry/geometries/concepts/check.hpp> | |
30 | ||
31 | #include <boost/geometry/algorithms/not_implemented.hpp> | |
32 | ||
33 | #include <boost/geometry/algorithms/detail/counting.hpp> | |
34 | ||
35 | ||
36 | namespace boost { namespace geometry | |
37 | { | |
38 | ||
39 | #ifndef DOXYGEN_NO_DETAIL | |
40 | namespace detail { namespace num_segments | |
41 | { | |
42 | ||
43 | ||
44 | struct range_count | |
45 | { | |
46 | template <typename Range> | |
47 | static inline std::size_t apply(Range const& range) | |
48 | { | |
49 | std::size_t n = boost::size(range); | |
50 | if ( n <= 1 ) | |
51 | { | |
52 | return 0; | |
53 | } | |
54 | ||
55 | return | |
56 | geometry::closure<Range>::value == open | |
57 | ? | |
58 | n | |
59 | : | |
60 | static_cast<std::size_t>(n - 1); | |
61 | } | |
62 | }; | |
63 | ||
64 | }} // namespace detail::num_segments | |
65 | #endif // DOXYGEN_NO_DETAIL | |
66 | ||
67 | ||
68 | ||
69 | #ifndef DOXYGEN_NO_DISPATCH | |
70 | namespace dispatch | |
71 | { | |
72 | ||
73 | template <typename Geometry, typename Tag = typename tag<Geometry>::type> | |
74 | struct num_segments | |
75 | : not_implemented<Tag> | |
76 | {}; | |
77 | ||
78 | template <typename Geometry> | |
79 | struct num_segments<Geometry, point_tag> | |
80 | : detail::counting::other_count<0> | |
81 | {}; | |
82 | ||
83 | // the number of segments (1-dimensional faces) of the hypercube is | |
84 | // given by the formula: d * 2^(d-1), where d is the dimension of the | |
85 | // hypercube; see also: | |
86 | // http://en.wikipedia.org/wiki/Hypercube | |
87 | template <typename Geometry> | |
88 | struct num_segments<Geometry, box_tag> | |
89 | : detail::counting::other_count | |
90 | < | |
91 | geometry::dimension<Geometry>::value | |
92 | * (1 << (geometry::dimension<Geometry>::value - 1)) | |
93 | > | |
94 | {}; | |
95 | ||
96 | template <typename Geometry> | |
97 | struct num_segments<Geometry, segment_tag> | |
98 | : detail::counting::other_count<1> | |
99 | {}; | |
100 | ||
101 | template <typename Geometry> | |
102 | struct num_segments<Geometry, linestring_tag> | |
103 | : detail::num_segments::range_count | |
104 | {}; | |
105 | ||
106 | template <typename Geometry> | |
107 | struct num_segments<Geometry, ring_tag> | |
108 | : detail::num_segments::range_count | |
109 | {}; | |
110 | ||
111 | template <typename Geometry> | |
112 | struct num_segments<Geometry, polygon_tag> | |
113 | : detail::counting::polygon_count<detail::num_segments::range_count> | |
114 | {}; | |
115 | ||
116 | template <typename Geometry> | |
117 | struct num_segments<Geometry, multi_point_tag> | |
118 | : detail::counting::other_count<0> | |
119 | {}; | |
120 | ||
121 | template <typename Geometry> | |
122 | struct num_segments<Geometry, multi_linestring_tag> | |
123 | : detail::counting::multi_count | |
124 | < | |
125 | num_segments< typename boost::range_value<Geometry>::type> | |
126 | > | |
127 | {}; | |
128 | ||
129 | template <typename Geometry> | |
130 | struct num_segments<Geometry, multi_polygon_tag> | |
131 | : detail::counting::multi_count | |
132 | < | |
133 | num_segments< typename boost::range_value<Geometry>::type> | |
134 | > | |
135 | {}; | |
136 | ||
137 | ||
138 | } // namespace dispatch | |
139 | #endif // DOXYGEN_NO_DISPATCH | |
140 | ||
141 | ||
142 | ||
143 | namespace resolve_variant | |
144 | { | |
145 | ||
146 | ||
147 | template <typename Geometry> | |
148 | struct num_segments | |
149 | { | |
150 | static inline std::size_t apply(Geometry const& geometry) | |
151 | { | |
152 | concepts::check<Geometry const>(); | |
153 | ||
154 | return dispatch::num_segments<Geometry>::apply(geometry); | |
155 | } | |
156 | }; | |
157 | ||
158 | ||
159 | template <BOOST_VARIANT_ENUM_PARAMS(typename T)> | |
160 | struct num_segments<boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> > | |
161 | { | |
162 | struct visitor: boost::static_visitor<std::size_t> | |
163 | { | |
164 | template <typename Geometry> | |
165 | inline std::size_t operator()(Geometry const& geometry) const | |
166 | { | |
167 | return num_segments<Geometry>::apply(geometry); | |
168 | } | |
169 | }; | |
170 | ||
171 | static inline std::size_t | |
172 | apply(boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> const& geometry) | |
173 | { | |
174 | return boost::apply_visitor(visitor(), geometry); | |
175 | } | |
176 | }; | |
177 | ||
178 | ||
179 | } // namespace resolve_variant | |
180 | ||
181 | ||
182 | ||
183 | /*! | |
184 | \brief \brief_calc{number of segments} | |
185 | \ingroup num_segments | |
186 | \details \details_calc{num_segments, number of segments}. | |
187 | \tparam Geometry \tparam_geometry | |
188 | \param geometry \param_geometry | |
189 | \return \return_calc{number of segments} | |
190 | ||
191 | \qbk{[include reference/algorithms/num_segments.qbk]} | |
192 | */ | |
193 | template <typename Geometry> | |
194 | inline std::size_t num_segments(Geometry const& geometry) | |
195 | { | |
196 | return resolve_variant::num_segments<Geometry>::apply(geometry); | |
197 | } | |
198 | ||
199 | ||
200 | ||
201 | }} // namespace boost::geometry | |
202 | ||
203 | #endif // BOOST_GEOMETRY_ALGORITHMS_NUM_SEGMENTS_HPP |