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

   1 // Boost.Geometry Index
   2 //
   3 // n-dimensional box's margin value (hypersurface), 2d perimeter, 3d surface, etc...
   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_MARGIN_HPP
  12 #define BOOST_GEOMETRY_INDEX_DETAIL_ALGORITHMS_MARGIN_HPP
  13
  14 // WARNING! comparable_margin() will work only if the same Geometries are compared
  15 // so it shouldn't be used in the case of Variants!
  16
  17 namespace boost { namespace geometry { namespace index { namespace detail {
  18
  19 template <typename Box>
  20 struct default_margin_result
  21 {
  22     typedef typename select_most_precise<
  23         typename coordinate_type<Box>::type,
  24         long double
  25     >::type type;
  26 };
  27
  28 //template <typename Box,
  29 //          std::size_t CurrentDimension,
  30 //          std::size_t EdgeDimension = dimension<Box>::value>
  31 //struct margin_for_each_edge
  32 //{
  33 //    BOOST_STATIC_ASSERT(0 < CurrentDimension);
  34 //    BOOST_STATIC_ASSERT(0 < EdgeDimension);
  35 //
  36 //    static inline typename default_margin_result<Box>::type apply(Box const& b)
  37 //    {
  38 //        return margin_for_each_edge<Box, CurrentDimension, EdgeDimension - 1>::apply(b) *
  39 //            ( geometry::get<max_corner, EdgeDimension - 1>(b) - geometry::get<min_corner, EdgeDimension - 1>(b) );
  40 //    }
  41 //};
  42 //
  43 //template <typename Box, std::size_t CurrentDimension>
  44 //struct margin_for_each_edge<Box, CurrentDimension, CurrentDimension>
  45 //{
  46 //    BOOST_STATIC_ASSERT(0 < CurrentDimension);
  47 //
  48 //    static inline typename default_margin_result<Box>::type apply(Box const& b)
  49 //    {
  50 //        return margin_for_each_edge<Box, CurrentDimension, CurrentDimension - 1>::apply(b);
  51 //    }
  52 //};
  53 //
  54 //template <typename Box, std::size_t CurrentDimension>
  55 //struct margin_for_each_edge<Box, CurrentDimension, 1>
  56 //{
  57 //    BOOST_STATIC_ASSERT(0 < CurrentDimension);
  58 //
  59 //    static inline typename default_margin_result<Box>::type apply(Box const& b)
  60 //    {
  61 //        return geometry::get<max_corner, 0>(b) - geometry::get<min_corner, 0>(b);
  62 //    }
  63 //};
  64 //
  65 //template <typename Box>
  66 //struct margin_for_each_edge<Box, 1, 1>
  67 //{
  68 //    static inline typename default_margin_result<Box>::type apply(Box const& /*b*/)
  69 //    {
  70 //        return 1;
  71 //    }
  72 //};
  73 //
  74 //template <typename Box,
  75 //          std::size_t CurrentDimension = dimension<Box>::value>
  76 //struct margin_for_each_dimension
  77 //{
  78 //    BOOST_STATIC_ASSERT(0 < CurrentDimension);
  79 //
  80 //    static inline typename default_margin_result<Box>::type apply(Box const& b)
  81 //    {
  82 //        return margin_for_each_dimension<Box, CurrentDimension - 1>::apply(b) +
  83 //            margin_for_each_edge<Box, CurrentDimension>::apply(b);
  84 //    }
  85 //};
  86 //
  87 //template <typename Box>
  88 //struct margin_for_each_dimension<Box, 1>
  89 //{
  90 //    static inline typename default_margin_result<Box>::type apply(Box const& b)
  91 //    {
  92 //        return margin_for_each_edge<Box, 1>::apply(b);
  93 //    }
  94 //};
  95
  96 // TODO - test if this definition of margin is ok for Dimension > 2
  97 // Now it's sum of edges lengths
  98 // maybe margin_for_each_dimension should be used to get more or less hypersurface?
  99
 100 template <typename Box,
 101           std::size_t CurrentDimension = dimension<Box>::value>
 102 struct simple_margin_for_each_dimension
 103 {
 104     BOOST_STATIC_ASSERT(0 < CurrentDimension);
 105
 106     static inline typename default_margin_result<Box>::type apply(Box const& b)
 107     {
 108         return simple_margin_for_each_dimension<Box, CurrentDimension - 1>::apply(b) +
 109             geometry::get<max_corner, CurrentDimension - 1>(b) - geometry::get<min_corner, CurrentDimension - 1>(b);
 110     }
 111 };
 112
 113 template <typename Box>
 114 struct simple_margin_for_each_dimension<Box, 1>
 115 {
 116     static inline typename default_margin_result<Box>::type apply(Box const& b)
 117     {
 118         return geometry::get<max_corner, 0>(b) - geometry::get<min_corner, 0>(b);
 119     }
 120 };
 121
 122 namespace dispatch {
 123
 124 template <typename Geometry, typename Tag>
 125 struct comparable_margin
 126 {
 127     BOOST_MPL_ASSERT_MSG(false, NOT_IMPLEMENTED_FOR_THIS_GEOMETRY, (Geometry, Tag));
 128 };
 129
 130 template <typename Geometry>
 131 struct comparable_margin<Geometry, point_tag>
 132 {
 133     typedef typename default_margin_result<Geometry>::type result_type;
 134
 135     static inline result_type apply(Geometry const& ) { return 0; }
 136 };
 137
 138 template <typename Box>
 139 struct comparable_margin<Box, box_tag>
 140 {
 141     typedef typename default_margin_result<Box>::type result_type;
 142
 143     static inline result_type apply(Box const& g)
 144     {
 145         //return detail::margin_for_each_dimension<Box>::apply(g);
 146         return detail::simple_margin_for_each_dimension<Box>::apply(g);
 147     }
 148 };
 149
 150 } // namespace dispatch
 151
 152 template <typename Geometry>
 153 typename default_margin_result<Geometry>::type comparable_margin(Geometry const& g)
 154 {
 155     return dispatch::comparable_margin<
 156         Geometry,
 157         typename tag<Geometry>::type
 158     >::apply(g);
 159 }
 160
 161 //template <typename Box>
 162 //typename default_margin_result<Box>::type margin(Box const& b)
 163 //{
 164 //    return 2 * detail::margin_for_each_dimension<Box>::apply(b);
 165 //}
 166
 167 }}}} // namespace boost::geometry::index::detail
 168
 169 #endif // BOOST_GEOMETRY_INDEX_DETAIL_ALGORITHMS_MARGIN_HPP