Chris@16: // Boost.Geometry Index
Chris@16: //
Chris@16: // Spatial index distance predicates, calculators and checkers
Chris@16: // used in nearest query - specialized for envelopes
Chris@16: //
Chris@101: // Copyright (c) 2011-2015 Adam Wulkiewicz, Lodz, Poland.
Chris@16: //
Chris@16: // Use, modification and distribution is subject to the Boost Software License,
Chris@16: // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_GEOMETRY_INDEX_DETAIL_DISTANCE_PREDICATES_HPP
Chris@16: #define BOOST_GEOMETRY_INDEX_DETAIL_DISTANCE_PREDICATES_HPP
Chris@16: 
Chris@16: #include <boost/geometry/index/detail/algorithms/comparable_distance_near.hpp>
Chris@16: #include <boost/geometry/index/detail/algorithms/comparable_distance_far.hpp>
Chris@16: #include <boost/geometry/index/detail/algorithms/comparable_distance_centroid.hpp>
Chris@16: #include <boost/geometry/index/detail/algorithms/path_intersection.hpp>
Chris@16: 
Chris@16: #include <boost/geometry/index/detail/tags.hpp>
Chris@16: 
Chris@16: namespace boost { namespace geometry { namespace index { namespace detail {
Chris@16: 
Chris@16: // ------------------------------------------------------------------ //
Chris@16: // relations
Chris@16: // ------------------------------------------------------------------ //
Chris@16: 
Chris@16: template <typename T>
Chris@16: struct to_nearest
Chris@16: {
Chris@16:     to_nearest(T const& v) : value(v) {}
Chris@16:     T value;
Chris@16: };
Chris@16: 
Chris@16: template <typename T>
Chris@16: struct to_centroid
Chris@16: {
Chris@16:     to_centroid(T const& v) : value(v) {}
Chris@16:     T value;
Chris@16: };
Chris@16: 
Chris@16: template <typename T>
Chris@16: struct to_furthest
Chris@16: {
Chris@16:     to_furthest(T const& v) : value(v) {}
Chris@16:     T value;
Chris@16: };
Chris@16: 
Chris@16: // tags
Chris@16: 
Chris@16: struct to_nearest_tag {};
Chris@16: struct to_centroid_tag {};
Chris@16: struct to_furthest_tag {};
Chris@16: 
Chris@16: // ------------------------------------------------------------------ //
Chris@16: // relation traits and access
Chris@16: // ------------------------------------------------------------------ //
Chris@16: 
Chris@16: template <typename T>
Chris@16: struct relation
Chris@16: {
Chris@16:     typedef T value_type;
Chris@16:     typedef to_nearest_tag tag;
Chris@16:     static inline T const& value(T const& v) { return v; }
Chris@16:     static inline T & value(T & v) { return v; }
Chris@16: };
Chris@16: 
Chris@16: template <typename T>
Chris@16: struct relation< to_nearest<T> >
Chris@16: {
Chris@16:     typedef T value_type;
Chris@16:     typedef to_nearest_tag tag;
Chris@16:     static inline T const& value(to_nearest<T> const& r) { return r.value; }
Chris@16:     static inline T & value(to_nearest<T> & r) { return r.value; }
Chris@16: };
Chris@16: 
Chris@16: template <typename T>
Chris@16: struct relation< to_centroid<T> >
Chris@16: {
Chris@16:     typedef T value_type;
Chris@16:     typedef to_centroid_tag tag;
Chris@16:     static inline T const& value(to_centroid<T> const& r) { return r.value; }
Chris@16:     static inline T & value(to_centroid<T> & r) { return r.value; }
Chris@16: };
Chris@16: 
Chris@16: template <typename T>
Chris@16: struct relation< to_furthest<T> >
Chris@16: {
Chris@16:     typedef T value_type;
Chris@16:     typedef to_furthest_tag tag;
Chris@16:     static inline T const& value(to_furthest<T> const& r) { return r.value; }
Chris@16:     static inline T & value(to_furthest<T> & r) { return r.value; }
Chris@16: };
Chris@16: 
Chris@16: // ------------------------------------------------------------------ //
Chris@16: // calculate_distance
Chris@16: // ------------------------------------------------------------------ //
Chris@16: 
Chris@16: template <typename Predicate, typename Indexable, typename Tag>
Chris@16: struct calculate_distance
Chris@16: {
Chris@16:     BOOST_MPL_ASSERT_MSG((false), INVALID_PREDICATE_OR_TAG, (calculate_distance));
Chris@16: };
Chris@16: 
Chris@16: // this handles nearest() with default Point parameter, to_nearest() and bounds
Chris@16: template <typename PointRelation, typename Indexable, typename Tag>
Chris@101: struct calculate_distance< predicates::nearest<PointRelation>, Indexable, Tag >
Chris@16: {
Chris@16:     typedef detail::relation<PointRelation> relation;
Chris@16:     typedef typename relation::value_type point_type;
Chris@101:     typedef typename geometry::default_comparable_distance_result<point_type, Indexable>::type result_type;
Chris@16: 
Chris@101:     static inline bool apply(predicates::nearest<PointRelation> const& p, Indexable const& i, result_type & result)
Chris@16:     {
Chris@101:         result = geometry::comparable_distance(relation::value(p.point_or_relation), i);
Chris@16:         return true;
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: template <typename Point, typename Indexable>
Chris@101: struct calculate_distance< predicates::nearest< to_centroid<Point> >, Indexable, value_tag>
Chris@16: {
Chris@16:     typedef Point point_type;
Chris@101:     typedef typename geometry::default_comparable_distance_result<point_type, Indexable>::type result_type;
Chris@16: 
Chris@101:     static inline bool apply(predicates::nearest< to_centroid<Point> > const& p, Indexable const& i, result_type & result)
Chris@16:     {
Chris@16:         result = index::detail::comparable_distance_centroid(p.point_or_relation.value, i);
Chris@16:         return true;
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: template <typename Point, typename Indexable>
Chris@101: struct calculate_distance< predicates::nearest< to_furthest<Point> >, Indexable, value_tag>
Chris@16: {
Chris@16:     typedef Point point_type;
Chris@101:     typedef typename geometry::default_comparable_distance_result<point_type, Indexable>::type result_type;
Chris@16: 
Chris@101:     static inline bool apply(predicates::nearest< to_furthest<Point> > const& p, Indexable const& i, result_type & result)
Chris@16:     {
Chris@16:         result = index::detail::comparable_distance_far(p.point_or_relation.value, i);
Chris@16:         return true;
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: template <typename SegmentOrLinestring, typename Indexable, typename Tag>
Chris@101: struct calculate_distance< predicates::path<SegmentOrLinestring>, Indexable, Tag>
Chris@16: {
Chris@16:     typedef typename index::detail::default_path_intersection_distance_type<
Chris@16:         Indexable, SegmentOrLinestring
Chris@16:     >::type result_type;
Chris@16: 
Chris@101:     static inline bool apply(predicates::path<SegmentOrLinestring> const& p, Indexable const& i, result_type & result)
Chris@16:     {
Chris@16:         return index::detail::path_intersection(i, p.geometry, result);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: }}}} // namespace boost::geometry::index::detail
Chris@16: 
Chris@16: #endif // BOOST_GEOMETRY_INDEX_RTREE_DISTANCE_PREDICATES_HPP