ceph/src/boost/libs/geometry/include/boost/geometry/index/detail/algorithms/comparable_distance_near.hpp

   1 // Boost.Geometry Index
   2 //
   3 // squared distance between point and nearest point of the box or point
   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_COMPARABLE_DISTANCE_NEAR_HPP
  12 #define BOOST_GEOMETRY_INDEX_DETAIL_ALGORITHMS_COMPARABLE_DISTANCE_NEAR_HPP
  13
  14 #include <boost/geometry/index/detail/algorithms/sum_for_indexable.hpp>
  15
  16 namespace boost { namespace geometry { namespace index { namespace detail {
  17
  18 struct comparable_distance_near_tag {};
  19
  20 template <
  21     typename Point,
  22     typename PointIndexable,
  23     size_t N>
  24 struct sum_for_indexable<Point, PointIndexable, point_tag, comparable_distance_near_tag, N>
  25 {
  26     typedef typename geometry::default_comparable_distance_result<Point, PointIndexable>::type result_type;
  27
  28     inline static result_type apply(Point const& pt, PointIndexable const& i)
  29     {
  30         return geometry::comparable_distance(pt, i);
  31     }
  32 };
  33
  34 template <
  35     typename Point,
  36     typename BoxIndexable,
  37     size_t DimensionIndex>
  38 struct sum_for_indexable_dimension<Point, BoxIndexable, box_tag, comparable_distance_near_tag, DimensionIndex>
  39 {
  40     typedef typename geometry::default_comparable_distance_result<Point, BoxIndexable>::type result_type;
  41
  42     inline static result_type apply(Point const& pt, BoxIndexable const& i)
  43     {
  44         typedef typename coordinate_type<Point>::type point_coord_t;
  45         typedef typename coordinate_type<BoxIndexable>::type indexable_coord_t;
  46
  47         point_coord_t pt_c = geometry::get<DimensionIndex>(pt);
  48         indexable_coord_t ind_c_min = geometry::get<geometry::min_corner, DimensionIndex>(i);
  49         indexable_coord_t ind_c_max = geometry::get<geometry::max_corner, DimensionIndex>(i);
  50
  51         result_type diff = 0;
  52
  53         if ( pt_c < ind_c_min )
  54             diff = ind_c_min - pt_c;
  55         else if ( ind_c_max < pt_c )
  56             diff = pt_c - ind_c_max;
  57
  58         return diff * diff;
  59     }
  60 };
  61
  62 template <typename Point, typename Indexable>
  63 typename geometry::default_comparable_distance_result<Point, Indexable>::type
  64 comparable_distance_near(Point const& pt, Indexable const& i)
  65 {
  66     return detail::sum_for_indexable<
  67         Point,
  68         Indexable,
  69         typename tag<Indexable>::type,
  70         detail::comparable_distance_near_tag,
  71         dimension<Indexable>::value
  72     >::apply(pt, i);
  73 }
  74
  75 }}}} // namespace boost::geometry::index::detail
  76
  77 #endif // BOOST_GEOMETRY_INDEX_DETAIL_ALGORITHMS_COMPARABLE_DISTANCE_NEAR_HPP