ceph/src/boost/libs/geometry/include/boost/geometry/algorithms/detail/overlay/get_ring.hpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2
   3 // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
   4
   5 // Use, modification and distribution is subject to the Boost Software License,
   6 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   7 // http://www.boost.org/LICENSE_1_0.txt)
   8
   9 #ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_OVERLAY_GET_RING_HPP
  10 #define BOOST_GEOMETRY_ALGORITHMS_DETAIL_OVERLAY_GET_RING_HPP
  11
  12
  13 #include <boost/range.hpp>
  14
  15 #include <boost/geometry/core/assert.hpp>
  16 #include <boost/geometry/core/exterior_ring.hpp>
  17 #include <boost/geometry/core/interior_rings.hpp>
  18 #include <boost/geometry/core/ring_type.hpp>
  19 #include <boost/geometry/core/tags.hpp>
  20 #include <boost/geometry/algorithms/detail/ring_identifier.hpp>
  21 #include <boost/geometry/geometries/concepts/check.hpp>
  22 #include <boost/geometry/util/range.hpp>
  23
  24
  25 namespace boost { namespace geometry
  26 {
  27
  28
  29 #ifndef DOXYGEN_NO_DETAIL
  30 namespace detail { namespace overlay
  31 {
  32
  33
  34 template<typename Tag>
  35 struct get_ring
  36 {};
  37
  38 // A range of rings (multi-ring but that does not exist)
  39 // gets the "void" tag and is dispatched here.
  40 template<>
  41 struct get_ring<void>
  42 {
  43     template<typename Range>
  44     static inline typename boost::range_value<Range>::type const&
  45                 apply(ring_identifier const& id, Range const& container)
  46     {
  47         return range::at(container, id.multi_index);
  48     }
  49 };
  50
  51
  52
  53
  54 template<>
  55 struct get_ring<ring_tag>
  56 {
  57     template<typename Ring>
  58     static inline Ring const& apply(ring_identifier const& , Ring const& ring)
  59     {
  60         return ring;
  61     }
  62 };
  63
  64
  65 template<>
  66 struct get_ring<box_tag>
  67 {
  68     template<typename Box>
  69     static inline Box const& apply(ring_identifier const& ,
  70                     Box const& box)
  71     {
  72         return box;
  73     }
  74 };
  75
  76
  77 template<>
  78 struct get_ring<polygon_tag>
  79 {
  80     template<typename Polygon>
  81     static inline typename ring_return_type<Polygon const>::type const apply(
  82                 ring_identifier const& id,
  83                 Polygon const& polygon)
  84     {
  85         BOOST_GEOMETRY_ASSERT
  86             (
  87                 id.ring_index >= -1
  88                 && id.ring_index < int(boost::size(interior_rings(polygon)))
  89             );
  90         return id.ring_index < 0
  91             ? exterior_ring(polygon)
  92             : range::at(interior_rings(polygon), id.ring_index);
  93     }
  94 };
  95
  96
  97 template<>
  98 struct get_ring<multi_polygon_tag>
  99 {
 100     template<typename MultiPolygon>
 101     static inline typename ring_type<MultiPolygon>::type const& apply(
 102                 ring_identifier const& id,
 103                 MultiPolygon const& multi_polygon)
 104     {
 105         BOOST_GEOMETRY_ASSERT
 106             (
 107                 id.multi_index >= 0
 108                 && id.multi_index < int(boost::size(multi_polygon))
 109             );
 110         return get_ring<polygon_tag>::apply(id,
 111                     range::at(multi_polygon, id.multi_index));
 112     }
 113 };
 114
 115
 116 }} // namespace detail::overlay
 117 #endif // DOXYGEN_NO_DETAIL
 118
 119
 120 }} // namespace boost::geometry
 121
 122
 123 #endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_OVERLAY_GET_RING_HPP