1 // Boost.Geometry (aka GGL, Generic Geometry Library)
2
3 // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
4 // Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
5 // Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
6 // Copyright (c) 2014 Adam Wulkiewicz, Lodz, Poland.
7
8 // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
9 // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
10
11 // Use, modification and distribution is subject to the Boost Software License,
12 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
13 // http://www.boost.org/LICENSE_1_0.txt)
14
15 #ifndef BOOST_GEOMETRY_ALGORITHMS_REVERSE_HPP
16 #define BOOST_GEOMETRY_ALGORITHMS_REVERSE_HPP
17
18 #include <algorithm>
19
20 #include <boost/range.hpp>
21 #include <boost/type_traits/remove_reference.hpp>
22
23 #include <boost/variant/apply_visitor.hpp>
24 #include <boost/variant/static_visitor.hpp>
25 #include <boost/variant/variant_fwd.hpp>
26
27 #include <boost/geometry/algorithms/detail/interior_iterator.hpp>
28 #include <boost/geometry/algorithms/detail/multi_modify.hpp>
29 #include <boost/geometry/core/interior_rings.hpp>
30 #include <boost/geometry/core/tags.hpp>
31 #include <boost/geometry/geometries/concepts/check.hpp>
32
33
34 namespace boost { namespace geometry
35 {
36
37
38 #ifndef DOXYGEN_NO_DETAIL
39 namespace detail { namespace reverse
40 {
41
42
43 struct range_reverse
44 {
45 template <typename Range>
applyboost::geometry::detail::reverse::range_reverse46 static inline void apply(Range& range)
47 {
48 std::reverse(boost::begin(range), boost::end(range));
49 }
50 };
51
52
53 struct polygon_reverse: private range_reverse
54 {
55 template <typename Polygon>
applyboost::geometry::detail::reverse::polygon_reverse56 static inline void apply(Polygon& polygon)
57 {
58 range_reverse::apply(exterior_ring(polygon));
59
60 typename interior_return_type<Polygon>::type
61 rings = interior_rings(polygon);
62
63 for (typename detail::interior_iterator<Polygon>::type
64 it = boost::begin(rings); it != boost::end(rings); ++it)
65 {
66 range_reverse::apply(*it);
67 }
68 }
69 };
70
71
72 }} // namespace detail::reverse
73 #endif // DOXYGEN_NO_DETAIL
74
75
76 #ifndef DOXYGEN_NO_DISPATCH
77 namespace dispatch
78 {
79
80
81 template <typename Geometry, typename Tag = typename tag<Geometry>::type>
82 struct reverse
83 {
applyboost::geometry::dispatch::reverse84 static inline void apply(Geometry&)
85 {}
86 };
87
88
89 template <typename Ring>
90 struct reverse<Ring, ring_tag>
91 : detail::reverse::range_reverse
92 {};
93
94
95 template <typename LineString>
96 struct reverse<LineString, linestring_tag>
97 : detail::reverse::range_reverse
98 {};
99
100
101 template <typename Polygon>
102 struct reverse<Polygon, polygon_tag>
103 : detail::reverse::polygon_reverse
104 {};
105
106
107 template <typename Geometry>
108 struct reverse<Geometry, multi_linestring_tag>
109 : detail::multi_modify
110 <
111 Geometry,
112 detail::reverse::range_reverse
113 >
114 {};
115
116
117 template <typename Geometry>
118 struct reverse<Geometry, multi_polygon_tag>
119 : detail::multi_modify
120 <
121 Geometry,
122 detail::reverse::polygon_reverse
123 >
124 {};
125
126
127
128 } // namespace dispatch
129 #endif
130
131
132 namespace resolve_variant
133 {
134
135 template <typename Geometry>
136 struct reverse
137 {
applyboost::geometry::resolve_variant::reverse138 static void apply(Geometry& geometry)
139 {
140 concepts::check<Geometry>();
141 dispatch::reverse<Geometry>::apply(geometry);
142 }
143 };
144
145 template <BOOST_VARIANT_ENUM_PARAMS(typename T)>
146 struct reverse<boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> >
147 {
148 struct visitor: boost::static_visitor<void>
149 {
150 template <typename Geometry>
operator ()boost::geometry::resolve_variant::reverse::visitor151 void operator()(Geometry& geometry) const
152 {
153 reverse<Geometry>::apply(geometry);
154 }
155 };
156
applyboost::geometry::resolve_variant::reverse157 static inline void apply(boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>& geometry)
158 {
159 boost::apply_visitor(visitor(), geometry);
160 }
161 };
162
163 } // namespace resolve_variant
164
165
166 /*!
167 \brief Reverses the points within a geometry
168 \details Generic function to reverse a geometry. It resembles the std::reverse
169 functionality, but it takes the geometry type into account. Only for a ring
170 or for a linestring it is the same as the std::reverse.
171 \ingroup reverse
172 \tparam Geometry \tparam_geometry
173 \param geometry \param_geometry which will be reversed
174
175 \qbk{[include reference/algorithms/reverse.qbk]}
176 */
177 template <typename Geometry>
reverse(Geometry & geometry)178 inline void reverse(Geometry& geometry)
179 {
180 resolve_variant::reverse<Geometry>::apply(geometry);
181 }
182
183 }} // namespace boost::geometry
184
185
186 #endif // BOOST_GEOMETRY_ALGORITHMS_REVERSE_HPP
187