ceph/src/boost/boost/geometry/core/topological_dimension.hpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2
   3 // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
   4 // Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
   5 // Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
   6
   7 // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
   8 // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
   9
  10 // Use, modification and distribution is subject to the Boost Software License,
  11 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  12 // http://www.boost.org/LICENSE_1_0.txt)
  13
  14
  15 #ifndef BOOST_GEOMETRY_CORE_TOPOLOGICAL_DIMENSION_HPP
  16 #define BOOST_GEOMETRY_CORE_TOPOLOGICAL_DIMENSION_HPP
  17
  18
  19 #include <boost/mpl/int.hpp>
  20
  21
  22 #include <boost/geometry/core/tag.hpp>
  23 #include <boost/geometry/core/tags.hpp>
  24
  25
  26 namespace boost { namespace geometry
  27 {
  28
  29
  30 #ifndef DOXYGEN_NO_DISPATCH
  31 namespace core_dispatch
  32 {
  33
  34
  35 template <typename GeometryTag>
  36 struct top_dim {};
  37
  38
  39 template <>
  40 struct top_dim<point_tag>      : boost::mpl::int_<0> {};
  41
  42
  43 template <>
  44 struct top_dim<linestring_tag> : boost::mpl::int_<1> {};
  45
  46
  47 template <>
  48 struct top_dim<segment_tag>    : boost::mpl::int_<1> {};
  49
  50
  51 // ring: topological dimension of two, but some people say: 1 !!
  52 // NOTE: This is not OGC LinearRing!
  53 template <>
  54 struct top_dim<ring_tag>       : boost::mpl::int_<2> {};
  55
  56
  57 // TODO: This is wrong! Boxes may have various topological dimensions
  58 template <>
  59 struct top_dim<box_tag>        : boost::mpl::int_<2> {};
  60
  61
  62 template <>
  63 struct top_dim<polygon_tag>    : boost::mpl::int_<2> {};
  64
  65
  66 template <>
  67 struct top_dim<multi_point_tag> : boost::mpl::int_<0> {};
  68
  69
  70 template <>
  71 struct top_dim<multi_linestring_tag> : boost::mpl::int_<1> {};
  72
  73
  74 template <>
  75 struct top_dim<multi_polygon_tag> : boost::mpl::int_<2> {};
  76
  77
  78 } // namespace core_dispatch
  79 #endif
  80
  81
  82
  83
  84
  85 /*!
  86     \brief Meta-function returning the topological dimension of a geometry
  87     \details The topological dimension defines a point as 0-dimensional,
  88         a linestring as 1-dimensional,
  89         and a ring or polygon as 2-dimensional.
  90     \see http://www.math.okstate.edu/mathdept/dynamics/lecnotes/node36.html
  91     \ingroup core
  92 */
  93 template <typename Geometry>
  94 struct topological_dimension
  95     : core_dispatch::top_dim<typename tag<Geometry>::type> {};
  96
  97
  98 }} // namespace boost::geometry
  99
 100
 101 #endif // BOOST_GEOMETRY_CORE_TOPOLOGICAL_DIMENSION_HPP