]>
Commit | Line | Data |
---|---|---|
7c673cae FG |
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 | ||
7 | // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library | |
8 | // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands. | |
9 | ||
10 | // Use, modification and distribution is subject to the Boost Software License, | |
11 | // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at | |
12 | // http://www.boost.org/LICENSE_1_0.txt) | |
13 | ||
14 | #ifndef BOOST_GEOMETRY_ALGORITHMS_CLEAR_HPP | |
15 | #define BOOST_GEOMETRY_ALGORITHMS_CLEAR_HPP | |
16 | ||
17 | ||
18 | #include <boost/type_traits/remove_const.hpp> | |
19 | ||
20 | #include <boost/variant/apply_visitor.hpp> | |
21 | #include <boost/variant/static_visitor.hpp> | |
22 | #include <boost/variant/variant_fwd.hpp> | |
23 | ||
24 | #include <boost/geometry/algorithms/not_implemented.hpp> | |
25 | #include <boost/geometry/core/access.hpp> | |
26 | #include <boost/geometry/core/exterior_ring.hpp> | |
27 | #include <boost/geometry/core/interior_rings.hpp> | |
28 | #include <boost/geometry/core/mutable_range.hpp> | |
29 | #include <boost/geometry/core/tag_cast.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 | #ifndef DOXYGEN_NO_DETAIL | |
38 | namespace detail { namespace clear | |
39 | { | |
40 | ||
41 | template <typename Geometry> | |
42 | struct collection_clear | |
43 | { | |
44 | static inline void apply(Geometry& geometry) | |
45 | { | |
46 | traits::clear<Geometry>::apply(geometry); | |
47 | } | |
48 | }; | |
49 | ||
50 | template <typename Polygon> | |
51 | struct polygon_clear | |
52 | { | |
53 | static inline void apply(Polygon& polygon) | |
54 | { | |
55 | traits::clear | |
56 | < | |
57 | typename boost::remove_reference | |
58 | < | |
59 | typename traits::interior_mutable_type<Polygon>::type | |
60 | >::type | |
61 | >::apply(interior_rings(polygon)); | |
62 | traits::clear | |
63 | < | |
64 | typename boost::remove_reference | |
65 | < | |
66 | typename traits::ring_mutable_type<Polygon>::type | |
67 | >::type | |
68 | >::apply(exterior_ring(polygon)); | |
69 | } | |
70 | }; | |
71 | ||
72 | template <typename Geometry> | |
73 | struct no_action | |
74 | { | |
75 | static inline void apply(Geometry& ) | |
76 | { | |
77 | } | |
78 | }; | |
79 | ||
80 | ||
81 | }} // namespace detail::clear | |
82 | #endif // DOXYGEN_NO_DETAIL | |
83 | ||
84 | #ifndef DOXYGEN_NO_DISPATCH | |
85 | namespace dispatch | |
86 | { | |
87 | ||
88 | template | |
89 | < | |
90 | typename Geometry, | |
91 | typename Tag = typename tag_cast<typename tag<Geometry>::type, multi_tag>::type | |
92 | > | |
93 | struct clear: not_implemented<Tag> | |
94 | {}; | |
95 | ||
96 | // Point/box/segment do not have clear. So specialize to do nothing. | |
97 | template <typename Geometry> | |
98 | struct clear<Geometry, point_tag> | |
99 | : detail::clear::no_action<Geometry> | |
100 | {}; | |
101 | ||
102 | template <typename Geometry> | |
103 | struct clear<Geometry, box_tag> | |
104 | : detail::clear::no_action<Geometry> | |
105 | {}; | |
106 | ||
107 | template <typename Geometry> | |
108 | struct clear<Geometry, segment_tag> | |
109 | : detail::clear::no_action<Geometry> | |
110 | {}; | |
111 | ||
112 | template <typename Geometry> | |
113 | struct clear<Geometry, linestring_tag> | |
114 | : detail::clear::collection_clear<Geometry> | |
115 | {}; | |
116 | ||
117 | template <typename Geometry> | |
118 | struct clear<Geometry, ring_tag> | |
119 | : detail::clear::collection_clear<Geometry> | |
120 | {}; | |
121 | ||
122 | ||
123 | // Polygon can (indirectly) use std for clear | |
124 | template <typename Polygon> | |
125 | struct clear<Polygon, polygon_tag> | |
126 | : detail::clear::polygon_clear<Polygon> | |
127 | {}; | |
128 | ||
129 | ||
130 | template <typename Geometry> | |
131 | struct clear<Geometry, multi_tag> | |
132 | : detail::clear::collection_clear<Geometry> | |
133 | {}; | |
134 | ||
135 | ||
136 | } // namespace dispatch | |
137 | #endif // DOXYGEN_NO_DISPATCH | |
138 | ||
139 | ||
140 | namespace resolve_variant { | |
141 | ||
142 | template <typename Geometry> | |
143 | struct clear | |
144 | { | |
145 | static inline void apply(Geometry& geometry) | |
146 | { | |
147 | dispatch::clear<Geometry>::apply(geometry); | |
148 | } | |
149 | }; | |
150 | ||
151 | template <BOOST_VARIANT_ENUM_PARAMS(typename T)> | |
152 | struct clear<variant<BOOST_VARIANT_ENUM_PARAMS(T)> > | |
153 | { | |
154 | struct visitor: static_visitor<void> | |
155 | { | |
156 | template <typename Geometry> | |
157 | inline void operator()(Geometry& geometry) const | |
158 | { | |
159 | clear<Geometry>::apply(geometry); | |
160 | } | |
161 | }; | |
162 | ||
163 | static inline void apply(variant<BOOST_VARIANT_ENUM_PARAMS(T)>& geometry) | |
164 | { | |
165 | boost::apply_visitor(visitor(), geometry); | |
166 | } | |
167 | }; | |
168 | ||
169 | } // namespace resolve_variant | |
170 | ||
171 | ||
172 | /*! | |
173 | \brief Clears a linestring, ring or polygon (exterior+interiors) or multi* | |
174 | \details Generic function to clear a geometry. All points will be removed from the collection or collections | |
175 | making up the geometry. In most cases this is equivalent to the .clear() method of a std::vector<...>. In | |
176 | the case of a polygon, this clear functionality is automatically called for the exterior ring, and for the | |
177 | interior ring collection. In the case of a point, boxes and segments, nothing will happen. | |
178 | \ingroup clear | |
179 | \tparam Geometry \tparam_geometry | |
180 | \param geometry \param_geometry which will be cleared | |
181 | \note points and boxes cannot be cleared, instead they can be set to zero by "assign_zero" | |
182 | ||
183 | \qbk{[include reference/algorithms/clear.qbk]} | |
184 | */ | |
185 | template <typename Geometry> | |
186 | inline void clear(Geometry& geometry) | |
187 | { | |
188 | concepts::check<Geometry>(); | |
189 | ||
190 | resolve_variant::clear<Geometry>::apply(geometry); | |
191 | } | |
192 | ||
193 | ||
194 | }} // namespace boost::geometry | |
195 | ||
196 | ||
197 | #endif // BOOST_GEOMETRY_ALGORITHMS_CLEAR_HPP |