ceph/src/boost/boost/geometry/index/detail/distance_predicates.hpp

   1 // Boost.Geometry Index
   2 //
   3 // Spatial index distance predicates, calculators and checkers
   4 // used in nearest query - specialized for envelopes
   5 //
   6 // Copyright (c) 2011-2015 Adam Wulkiewicz, Lodz, Poland.
   7 //
   8 // Use, modification and distribution is subject to the Boost Software License,
   9 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  10 // http://www.boost.org/LICENSE_1_0.txt)
  11
  12 #ifndef BOOST_GEOMETRY_INDEX_DETAIL_DISTANCE_PREDICATES_HPP
  13 #define BOOST_GEOMETRY_INDEX_DETAIL_DISTANCE_PREDICATES_HPP
  14
  15 #include <boost/geometry/index/detail/algorithms/comparable_distance_near.hpp>
  16 #include <boost/geometry/index/detail/algorithms/comparable_distance_far.hpp>
  17 #include <boost/geometry/index/detail/algorithms/comparable_distance_centroid.hpp>
  18 #include <boost/geometry/index/detail/algorithms/path_intersection.hpp>
  19
  20 #include <boost/geometry/index/detail/tags.hpp>
  21
  22 namespace boost { namespace geometry { namespace index { namespace detail {
  23
  24 // ------------------------------------------------------------------ //
  25 // relations
  26 // ------------------------------------------------------------------ //
  27
  28 template <typename T>
  29 struct to_nearest
  30 {
  31     to_nearest(T const& v) : value(v) {}
  32     T value;
  33 };
  34
  35 template <typename T>
  36 struct to_centroid
  37 {
  38     to_centroid(T const& v) : value(v) {}
  39     T value;
  40 };
  41
  42 template <typename T>
  43 struct to_furthest
  44 {
  45     to_furthest(T const& v) : value(v) {}
  46     T value;
  47 };
  48
  49 // tags
  50
  51 struct to_nearest_tag {};
  52 struct to_centroid_tag {};
  53 struct to_furthest_tag {};
  54
  55 // ------------------------------------------------------------------ //
  56 // relation traits and access
  57 // ------------------------------------------------------------------ //
  58
  59 template <typename T>
  60 struct relation
  61 {
  62     typedef T value_type;
  63     typedef to_nearest_tag tag;
  64     static inline T const& value(T const& v) { return v; }
  65     static inline T & value(T & v) { return v; }
  66 };
  67
  68 template <typename T>
  69 struct relation< to_nearest<T> >
  70 {
  71     typedef T value_type;
  72     typedef to_nearest_tag tag;
  73     static inline T const& value(to_nearest<T> const& r) { return r.value; }
  74     static inline T & value(to_nearest<T> & r) { return r.value; }
  75 };
  76
  77 template <typename T>
  78 struct relation< to_centroid<T> >
  79 {
  80     typedef T value_type;
  81     typedef to_centroid_tag tag;
  82     static inline T const& value(to_centroid<T> const& r) { return r.value; }
  83     static inline T & value(to_centroid<T> & r) { return r.value; }
  84 };
  85
  86 template <typename T>
  87 struct relation< to_furthest<T> >
  88 {
  89     typedef T value_type;
  90     typedef to_furthest_tag tag;
  91     static inline T const& value(to_furthest<T> const& r) { return r.value; }
  92     static inline T & value(to_furthest<T> & r) { return r.value; }
  93 };
  94
  95 // ------------------------------------------------------------------ //
  96 // calculate_distance
  97 // ------------------------------------------------------------------ //
  98
  99 template <typename Predicate, typename Indexable, typename Tag>
 100 struct calculate_distance
 101 {
 102     BOOST_MPL_ASSERT_MSG((false), INVALID_PREDICATE_OR_TAG, (calculate_distance));
 103 };
 104
 105 // this handles nearest() with default Point parameter, to_nearest() and bounds
 106 template <typename PointRelation, typename Indexable, typename Tag>
 107 struct calculate_distance< predicates::nearest<PointRelation>, Indexable, Tag >
 108 {
 109     typedef detail::relation<PointRelation> relation;
 110     typedef typename relation::value_type point_type;
 111     typedef typename geometry::default_comparable_distance_result<point_type, Indexable>::type result_type;
 112
 113     static inline bool apply(predicates::nearest<PointRelation> const& p, Indexable const& i, result_type & result)
 114     {
 115         result = geometry::comparable_distance(relation::value(p.point_or_relation), i);
 116         return true;
 117     }
 118 };
 119
 120 template <typename Point, typename Indexable>
 121 struct calculate_distance< predicates::nearest< to_centroid<Point> >, Indexable, value_tag>
 122 {
 123     typedef Point point_type;
 124     typedef typename geometry::default_comparable_distance_result<point_type, Indexable>::type result_type;
 125
 126     static inline bool apply(predicates::nearest< to_centroid<Point> > const& p, Indexable const& i, result_type & result)
 127     {
 128         result = index::detail::comparable_distance_centroid(p.point_or_relation.value, i);
 129         return true;
 130     }
 131 };
 132
 133 template <typename Point, typename Indexable>
 134 struct calculate_distance< predicates::nearest< to_furthest<Point> >, Indexable, value_tag>
 135 {
 136     typedef Point point_type;
 137     typedef typename geometry::default_comparable_distance_result<point_type, Indexable>::type result_type;
 138
 139     static inline bool apply(predicates::nearest< to_furthest<Point> > const& p, Indexable const& i, result_type & result)
 140     {
 141         result = index::detail::comparable_distance_far(p.point_or_relation.value, i);
 142         return true;
 143     }
 144 };
 145
 146 template <typename SegmentOrLinestring, typename Indexable, typename Tag>
 147 struct calculate_distance< predicates::path<SegmentOrLinestring>, Indexable, Tag>
 148 {
 149     typedef typename index::detail::default_path_intersection_distance_type<
 150         Indexable, SegmentOrLinestring
 151     >::type result_type;
 152
 153     static inline bool apply(predicates::path<SegmentOrLinestring> const& p, Indexable const& i, result_type & result)
 154     {
 155         return index::detail::path_intersection(i, p.geometry, result);
 156     }
 157 };
 158
 159 }}}} // namespace boost::geometry::index::detail
 160
 161 #endif // BOOST_GEOMETRY_INDEX_RTREE_DISTANCE_PREDICATES_HPP