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