1 | // Boost.Geometry Index |
2 | // |
3 | // n-dimensional box's margin value (hypersurface), 2d perimeter, 3d surface, etc... |
4 | // |
5 | // Copyright (c) 2011-2014 Adam Wulkiewicz, Lodz, Poland. |
6 | // |
7 | // Use, modification and distribution is subject to the Boost Software License, |
8 | // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at |
9 | // http://www.boost.org/LICENSE_1_0.txt) |
10 | |
11 | #ifndef BOOST_GEOMETRY_INDEX_DETAIL_ALGORITHMS_MARGIN_HPP |
12 | #define BOOST_GEOMETRY_INDEX_DETAIL_ALGORITHMS_MARGIN_HPP |
13 | |
14 | // WARNING! comparable_margin() will work only if the same Geometries are compared |
15 | // so it shouldn't be used in the case of Variants! |
16 | |
17 | namespace boost { namespace geometry { namespace index { namespace detail { |
18 | |
19 | template <typename Box> |
20 | struct default_margin_result |
21 | { |
22 | typedef typename select_most_precise< |
23 | typename coordinate_type<Box>::type, |
24 | long double |
25 | >::type type; |
26 | }; |
27 | |
28 | //template <typename Box, |
29 | // std::size_t CurrentDimension, |
30 | // std::size_t EdgeDimension = dimension<Box>::value> |
31 | //struct margin_for_each_edge |
32 | //{ |
33 | // BOOST_STATIC_ASSERT(0 < CurrentDimension); |
34 | // BOOST_STATIC_ASSERT(0 < EdgeDimension); |
35 | // |
36 | // static inline typename default_margin_result<Box>::type apply(Box const& b) |
37 | // { |
38 | // return margin_for_each_edge<Box, CurrentDimension, EdgeDimension - 1>::apply(b) * |
39 | // ( geometry::get<max_corner, EdgeDimension - 1>(b) - geometry::get<min_corner, EdgeDimension - 1>(b) ); |
40 | // } |
41 | //}; |
42 | // |
43 | //template <typename Box, std::size_t CurrentDimension> |
44 | //struct margin_for_each_edge<Box, CurrentDimension, CurrentDimension> |
45 | //{ |
46 | // BOOST_STATIC_ASSERT(0 < CurrentDimension); |
47 | // |
48 | // static inline typename default_margin_result<Box>::type apply(Box const& b) |
49 | // { |
50 | // return margin_for_each_edge<Box, CurrentDimension, CurrentDimension - 1>::apply(b); |
51 | // } |
52 | //}; |
53 | // |
54 | //template <typename Box, std::size_t CurrentDimension> |
55 | //struct margin_for_each_edge<Box, CurrentDimension, 1> |
56 | //{ |
57 | // BOOST_STATIC_ASSERT(0 < CurrentDimension); |
58 | // |
59 | // static inline typename default_margin_result<Box>::type apply(Box const& b) |
60 | // { |
61 | // return geometry::get<max_corner, 0>(b) - geometry::get<min_corner, 0>(b); |
62 | // } |
63 | //}; |
64 | // |
65 | //template <typename Box> |
66 | //struct margin_for_each_edge<Box, 1, 1> |
67 | //{ |
68 | // static inline typename default_margin_result<Box>::type apply(Box const& /*b*/) |
69 | // { |
70 | // return 1; |
71 | // } |
72 | //}; |
73 | // |
74 | //template <typename Box, |
75 | // std::size_t CurrentDimension = dimension<Box>::value> |
76 | //struct margin_for_each_dimension |
77 | //{ |
78 | // BOOST_STATIC_ASSERT(0 < CurrentDimension); |
79 | // |
80 | // static inline typename default_margin_result<Box>::type apply(Box const& b) |
81 | // { |
82 | // return margin_for_each_dimension<Box, CurrentDimension - 1>::apply(b) + |
83 | // margin_for_each_edge<Box, CurrentDimension>::apply(b); |
84 | // } |
85 | //}; |
86 | // |
87 | //template <typename Box> |
88 | //struct margin_for_each_dimension<Box, 1> |
89 | //{ |
90 | // static inline typename default_margin_result<Box>::type apply(Box const& b) |
91 | // { |
92 | // return margin_for_each_edge<Box, 1>::apply(b); |
93 | // } |
94 | //}; |
95 | |
96 | // TODO - test if this definition of margin is ok for Dimension > 2 |
97 | // Now it's sum of edges lengths |
98 | // maybe margin_for_each_dimension should be used to get more or less hypersurface? |
99 | |
100 | template <typename Box, |
101 | std::size_t CurrentDimension = dimension<Box>::value> |
102 | struct simple_margin_for_each_dimension |
103 | { |
104 | BOOST_STATIC_ASSERT(0 < CurrentDimension); |
105 | |
106 | static inline typename default_margin_result<Box>::type apply(Box const& b) |
107 | { |
108 | return simple_margin_for_each_dimension<Box, CurrentDimension - 1>::apply(b) + |
109 | geometry::get<max_corner, CurrentDimension - 1>(b) - geometry::get<min_corner, CurrentDimension - 1>(b); |
110 | } |
111 | }; |
112 | |
113 | template <typename Box> |
114 | struct simple_margin_for_each_dimension<Box, 1> |
115 | { |
116 | static inline typename default_margin_result<Box>::type apply(Box const& b) |
117 | { |
118 | return geometry::get<max_corner, 0>(b) - geometry::get<min_corner, 0>(b); |
119 | } |
120 | }; |
121 | |
122 | namespace dispatch { |
123 | |
124 | template <typename Geometry, typename Tag> |
125 | struct comparable_margin |
126 | { |
127 | BOOST_MPL_ASSERT_MSG(false, NOT_IMPLEMENTED_FOR_THIS_GEOMETRY, (Geometry, Tag)); |
128 | }; |
129 | |
130 | template <typename Geometry> |
131 | struct comparable_margin<Geometry, point_tag> |
132 | { |
133 | typedef typename default_margin_result<Geometry>::type result_type; |
134 | |
135 | static inline result_type apply(Geometry const& ) { return 0; } |
136 | }; |
137 | |
138 | template <typename Box> |
139 | struct comparable_margin<Box, box_tag> |
140 | { |
141 | typedef typename default_margin_result<Box>::type result_type; |
142 | |
143 | static inline result_type apply(Box const& g) |
144 | { |
145 | //return detail::margin_for_each_dimension<Box>::apply(g); |
146 | return detail::simple_margin_for_each_dimension<Box>::apply(g); |
147 | } |
148 | }; |
149 | |
150 | } // namespace dispatch |
151 | |
152 | template <typename Geometry> |
153 | typename default_margin_result<Geometry>::type comparable_margin(Geometry const& g) |
154 | { |
155 | return dispatch::comparable_margin< |
156 | Geometry, |
157 | typename tag<Geometry>::type |
158 | >::apply(g); |
159 | } |
160 | |
161 | //template <typename Box> |
162 | //typename default_margin_result<Box>::type margin(Box const& b) |
163 | //{ |
164 | // return 2 * detail::margin_for_each_dimension<Box>::apply(b); |
165 | //} |
166 | |
167 | }}}} // namespace boost::geometry::index::detail |
168 | |
169 | #endif // BOOST_GEOMETRY_INDEX_DETAIL_ALGORITHMS_MARGIN_HPP |
170 | |