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

   1 // Boost.Geometry Index
   2 //
   3 // squared distance between point and furthest 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_FAR_HPP
  12 #define BOOST_GEOMETRY_INDEX_DETAIL_ALGORITHMS_COMPARABLE_DISTANCE_FAR_HPP
  13
  14 #include <boost/geometry/index/detail/algorithms/diff_abs.hpp>
  15 #include <boost/geometry/index/detail/algorithms/sum_for_indexable.hpp>
  16
  17 namespace boost { namespace geometry { namespace index { namespace detail {
  18
  19 // minmaxdist component
  20
  21 struct comparable_distance_far_tag {};
  22
  23 template <
  24     typename Point,
  25     typename BoxIndexable,
  26     size_t DimensionIndex>
  27 struct sum_for_indexable_dimension<Point, BoxIndexable, box_tag, comparable_distance_far_tag, DimensionIndex>
  28 {
  29     typedef typename geometry::default_comparable_distance_result<Point, BoxIndexable>::type result_type;
  30
  31     inline static result_type apply(Point const& pt, BoxIndexable const& i)
  32     {
  33         typedef typename coordinate_type<Point>::type point_coord_t;
  34         typedef typename coordinate_type<BoxIndexable>::type indexable_coord_t;
  35
  36         point_coord_t pt_c = geometry::get<DimensionIndex>(pt);
  37         indexable_coord_t ind_c_min = geometry::get<geometry::min_corner, DimensionIndex>(i);
  38         indexable_coord_t ind_c_max = geometry::get<geometry::max_corner, DimensionIndex>(i);
  39
  40         result_type further_diff = 0;
  41
  42         if ( (ind_c_min + ind_c_max) / 2 <= pt_c )
  43             further_diff = pt_c - ind_c_min;
  44         else
  45             further_diff = detail::diff_abs(pt_c, ind_c_max); // unsigned values protection
  46
  47         return further_diff * further_diff;
  48     }
  49 };
  50
  51 template <typename Point, typename Indexable>
  52 typename geometry::default_comparable_distance_result<Point, Indexable>::type
  53 comparable_distance_far(Point const& pt, Indexable const& i)
  54 {
  55     return detail::sum_for_indexable<
  56         Point,
  57         Indexable,
  58         typename tag<Indexable>::type,
  59         detail::comparable_distance_far_tag,
  60         dimension<Indexable>::value
  61     >::apply(pt, i);
  62 }
  63
  64 }}}} // namespace boost::geometry::index::detail
  65
  66 #endif // BOOST_GEOMETRY_INDEX_DETAIL_ALGORITHMS_COMPARABLE_DISTANCE_FAR_HPP