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1 | // Boost.Geometry Index |
2 | // | |
3 | // n-dimensional box-linestring intersection | |
4 | // | |
b32b8144 | 5 | // Copyright (c) 2011-2017 Adam Wulkiewicz, Lodz, Poland. |
7c673cae FG |
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_PATH_INTERSECTION_HPP | |
12 | #define BOOST_GEOMETRY_INDEX_DETAIL_ALGORITHMS_PATH_INTERSECTION_HPP | |
13 | ||
b32b8144 | 14 | |
7c673cae FG |
15 | #include <boost/geometry/index/detail/algorithms/segment_intersection.hpp> |
16 | ||
b32b8144 FG |
17 | #include <boost/geometry/strategies/default_length_result.hpp> |
18 | ||
19 | ||
7c673cae FG |
20 | namespace boost { namespace geometry { namespace index { namespace detail { |
21 | ||
22 | namespace dispatch { | |
23 | ||
24 | template <typename Indexable, typename Geometry, typename IndexableTag, typename GeometryTag> | |
25 | struct path_intersection | |
26 | { | |
27 | BOOST_MPL_ASSERT_MSG((false), NOT_IMPLEMENTED_FOR_THIS_GEOMETRY_OR_INDEXABLE, (path_intersection)); | |
28 | }; | |
29 | ||
30 | // TODO: FP type must be used as a relative distance type! | |
31 | // and default_distance_result can be some user-defined int type | |
32 | // BUT! This code is experimental and probably won't be released at all | |
33 | // since more flexible user-defined-nearest predicate should be added instead | |
34 | ||
35 | template <typename Indexable, typename Segment> | |
36 | struct path_intersection<Indexable, Segment, box_tag, segment_tag> | |
37 | { | |
38 | typedef typename default_distance_result<typename point_type<Segment>::type>::type comparable_distance_type; | |
39 | ||
40 | static inline bool apply(Indexable const& b, Segment const& segment, comparable_distance_type & comparable_distance) | |
41 | { | |
42 | typedef typename point_type<Segment>::type point_type; | |
43 | point_type p1, p2; | |
44 | geometry::detail::assign_point_from_index<0>(segment, p1); | |
45 | geometry::detail::assign_point_from_index<1>(segment, p2); | |
46 | return index::detail::segment_intersection(b, p1, p2, comparable_distance); | |
47 | } | |
48 | }; | |
49 | ||
50 | template <typename Indexable, typename Linestring> | |
51 | struct path_intersection<Indexable, Linestring, box_tag, linestring_tag> | |
52 | { | |
53 | typedef typename default_length_result<Linestring>::type comparable_distance_type; | |
54 | ||
55 | static inline bool apply(Indexable const& b, Linestring const& path, comparable_distance_type & comparable_distance) | |
56 | { | |
57 | typedef typename ::boost::range_value<Linestring>::type point_type; | |
58 | typedef typename ::boost::range_const_iterator<Linestring>::type const_iterator; | |
59 | typedef typename ::boost::range_size<Linestring>::type size_type; | |
60 | ||
61 | const size_type count = ::boost::size(path); | |
62 | ||
63 | if ( count == 2 ) | |
64 | { | |
65 | return index::detail::segment_intersection(b, *::boost::begin(path), *(::boost::begin(path)+1), comparable_distance); | |
66 | } | |
67 | else if ( 2 < count ) | |
68 | { | |
69 | const_iterator it0 = ::boost::begin(path); | |
70 | const_iterator it1 = ::boost::begin(path) + 1; | |
71 | const_iterator last = ::boost::end(path); | |
72 | ||
73 | comparable_distance = 0; | |
74 | ||
75 | for ( ; it1 != last ; ++it0, ++it1 ) | |
76 | { | |
77 | typename default_distance_result<point_type, point_type>::type | |
78 | dist = geometry::distance(*it0, *it1); | |
79 | ||
80 | comparable_distance_type rel_dist; | |
81 | if ( index::detail::segment_intersection(b, *it0, *it1, rel_dist) ) | |
82 | { | |
83 | comparable_distance += dist * rel_dist; | |
84 | return true; | |
85 | } | |
86 | else | |
87 | comparable_distance += dist; | |
88 | } | |
89 | } | |
90 | ||
91 | return false; | |
92 | } | |
93 | }; | |
94 | ||
95 | } // namespace dispatch | |
96 | ||
97 | template <typename Indexable, typename SegmentOrLinestring> | |
98 | struct default_path_intersection_distance_type | |
99 | { | |
100 | typedef typename dispatch::path_intersection< | |
101 | Indexable, SegmentOrLinestring, | |
102 | typename tag<Indexable>::type, | |
103 | typename tag<SegmentOrLinestring>::type | |
104 | >::comparable_distance_type type; | |
105 | }; | |
106 | ||
107 | template <typename Indexable, typename SegmentOrLinestring> inline | |
108 | bool path_intersection(Indexable const& b, | |
109 | SegmentOrLinestring const& path, | |
110 | typename default_path_intersection_distance_type<Indexable, SegmentOrLinestring>::type & comparable_distance) | |
111 | { | |
112 | // TODO check Indexable and Linestring concepts | |
113 | ||
114 | return dispatch::path_intersection< | |
115 | Indexable, SegmentOrLinestring, | |
116 | typename tag<Indexable>::type, | |
117 | typename tag<SegmentOrLinestring>::type | |
118 | >::apply(b, path, comparable_distance); | |
119 | } | |
120 | ||
121 | }}}} // namespace boost::geometry::index::detail | |
122 | ||
123 | #endif // BOOST_GEOMETRY_INDEX_DETAIL_ALGORITHMS_PATH_INTERSECTION_HPP |