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 | // This file was modified by Oracle on 2014. |
8 | // Modifications copyright (c) 2014 Oracle and/or its affiliates. |
9 | |
10 | // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle |
11 | |
12 | // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library |
13 | // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands. |
14 | |
15 | // Use, modification and distribution is subject to the Boost Software License, |
16 | // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at |
17 | // http://www.boost.org/LICENSE_1_0.txt) |
18 | |
19 | #ifndef BOOST_GEOMETRY_CORE_POINT_ORDER_HPP |
20 | #define BOOST_GEOMETRY_CORE_POINT_ORDER_HPP |
21 | |
22 | |
23 | #include <boost/mpl/assert.hpp> |
24 | #include <boost/range/value_type.hpp> |
25 | #include <boost/type_traits/remove_const.hpp> |
26 | |
27 | #include <boost/geometry/core/ring_type.hpp> |
28 | #include <boost/geometry/core/tag.hpp> |
29 | #include <boost/geometry/core/tags.hpp> |
30 | |
31 | namespace boost { namespace geometry |
32 | { |
33 | |
34 | /*! |
35 | \brief Enumerates options for the order of points within polygons |
36 | \ingroup enum |
37 | \details The enumeration order_selector describes options for the order of |
38 | points within a polygon. Polygons can be ordered either clockwise or |
39 | counterclockwise. The specific order of a polygon type is defined by the |
40 | point_order metafunction. The point_order metafunction defines a value, |
41 | which is one of the values enumerated in the order_selector |
42 | |
43 | \qbk{ |
44 | [heading See also] |
45 | [link geometry.reference.core.point_order The point_order metafunction] |
46 | } |
47 | */ |
48 | enum order_selector |
49 | { |
50 | /// Points are ordered clockwise |
51 | clockwise = 1, |
52 | /// Points are ordered counter clockwise |
53 | counterclockwise = 2, |
54 | /// Points might be stored in any order, algorithms will determine it on the |
55 | /// fly (not yet supported) |
56 | order_undetermined = 0 |
57 | }; |
58 | |
59 | namespace traits |
60 | { |
61 | |
62 | /*! |
63 | \brief Traits class indicating the order of contained points within a |
64 | ring or (multi)polygon, clockwise, counter clockwise or not known. |
65 | \ingroup traits |
66 | \tparam Ring ring |
67 | */ |
68 | template <typename Ring> |
69 | struct point_order |
70 | { |
71 | static const order_selector value = clockwise; |
72 | }; |
73 | |
74 | |
75 | } // namespace traits |
76 | |
77 | |
78 | #ifndef DOXYGEN_NO_DETAIL |
79 | namespace detail { namespace point_order |
80 | { |
81 | |
82 | struct clockwise |
83 | { |
84 | static const order_selector value = geometry::clockwise; |
85 | }; |
86 | |
87 | |
88 | }} // namespace detail::point_order |
89 | #endif // DOXYGEN_NO_DETAIL |
90 | |
91 | |
92 | |
93 | #ifndef DOXYGEN_NO_DISPATCH |
94 | namespace core_dispatch |
95 | { |
96 | |
97 | template <typename Tag, typename Geometry> |
98 | struct point_order |
99 | { |
100 | BOOST_MPL_ASSERT_MSG |
101 | ( |
102 | false, NOT_IMPLEMENTED_FOR_THIS_GEOMETRY_TYPE |
103 | , (types<Geometry>) |
104 | ); |
105 | }; |
106 | |
107 | template <typename Point> |
108 | struct point_order<point_tag, Point> |
109 | : public detail::point_order::clockwise {}; |
110 | |
111 | template <typename Segment> |
112 | struct point_order<segment_tag, Segment> |
113 | : public detail::point_order::clockwise {}; |
114 | |
115 | |
116 | template <typename Box> |
117 | struct point_order<box_tag, Box> |
118 | : public detail::point_order::clockwise {}; |
119 | |
120 | template <typename LineString> |
121 | struct point_order<linestring_tag, LineString> |
122 | : public detail::point_order::clockwise {}; |
123 | |
124 | |
125 | template <typename Ring> |
126 | struct point_order<ring_tag, Ring> |
127 | { |
128 | static const order_selector value |
129 | = geometry::traits::point_order<Ring>::value; |
130 | }; |
131 | |
132 | // Specialization for polygon: the order is the order of its rings |
133 | template <typename Polygon> |
134 | struct point_order<polygon_tag, Polygon> |
135 | { |
136 | static const order_selector value = core_dispatch::point_order |
137 | < |
138 | ring_tag, |
139 | typename ring_type<polygon_tag, Polygon>::type |
140 | >::value ; |
141 | }; |
142 | |
143 | template <typename MultiPoint> |
144 | struct point_order<multi_point_tag, MultiPoint> |
145 | : public detail::point_order::clockwise {}; |
146 | |
147 | template <typename MultiLinestring> |
148 | struct point_order<multi_linestring_tag, MultiLinestring> |
149 | : public detail::point_order::clockwise {}; |
150 | |
151 | |
152 | // Specialization for multi_polygon: the order is the order of its polygons |
153 | template <typename MultiPolygon> |
154 | struct point_order<multi_polygon_tag, MultiPolygon> |
155 | { |
156 | static const order_selector value = core_dispatch::point_order |
157 | < |
158 | polygon_tag, |
159 | typename boost::range_value<MultiPolygon>::type |
160 | >::value ; |
161 | }; |
162 | |
163 | } // namespace core_dispatch |
164 | #endif // DOXYGEN_NO_DISPATCH |
165 | |
166 | |
167 | /*! |
168 | \brief \brief_meta{value, point order (clockwise\, counterclockwise), |
169 | \meta_geometry_type} |
170 | \tparam Geometry \tparam_geometry |
171 | \ingroup core |
172 | |
173 | \qbk{[include reference/core/point_order.qbk]} |
174 | */ |
175 | template <typename Geometry> |
176 | struct point_order |
177 | { |
178 | static const order_selector value = core_dispatch::point_order |
179 | < |
180 | typename tag<Geometry>::type, |
181 | typename util::bare_type<Geometry>::type |
182 | >::value; |
183 | }; |
184 | |
185 | }} // namespace boost::geometry |
186 | |
187 | #endif // BOOST_GEOMETRY_CORE_POINT_ORDER_HPP |
188 | |