topological_dimension.hpp 2.7 KB

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  1. // Boost.Geometry (aka GGL, Generic Geometry Library)
  2. // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
  3. // Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
  4. // Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
  5. // This file was modified by Oracle on 2020-2022.
  6. // Modifications copyright (c) 2020-2022, Oracle and/or its affiliates.
  7. // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
  8. // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
  9. // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
  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. #ifndef BOOST_GEOMETRY_CORE_TOPOLOGICAL_DIMENSION_HPP
  14. #define BOOST_GEOMETRY_CORE_TOPOLOGICAL_DIMENSION_HPP
  15. #include <type_traits>
  16. #include <boost/geometry/core/tag.hpp>
  17. #include <boost/geometry/core/tags.hpp>
  18. namespace boost { namespace geometry
  19. {
  20. #ifndef DOXYGEN_NO_DISPATCH
  21. namespace core_dispatch
  22. {
  23. template <typename GeometryTag>
  24. struct top_dim {};
  25. template <>
  26. struct top_dim<point_tag> : std::integral_constant<int, 0> {};
  27. template <>
  28. struct top_dim<linestring_tag> : std::integral_constant<int, 1> {};
  29. template <>
  30. struct top_dim<segment_tag> : std::integral_constant<int, 1> {};
  31. // ring: topological dimension of two, but some people say: 1 !!
  32. // NOTE: This is not OGC LinearRing!
  33. template <>
  34. struct top_dim<ring_tag> : std::integral_constant<int, 2> {};
  35. // TODO: This is wrong! Boxes may have various topological dimensions
  36. template <>
  37. struct top_dim<box_tag> : std::integral_constant<int, 2> {};
  38. template <>
  39. struct top_dim<polygon_tag> : std::integral_constant<int, 2> {};
  40. template <>
  41. struct top_dim<multi_point_tag> : std::integral_constant<int, 0> {};
  42. template <>
  43. struct top_dim<multi_linestring_tag> : std::integral_constant<int, 1> {};
  44. template <>
  45. struct top_dim<multi_polygon_tag> : std::integral_constant<int, 2> {};
  46. template <>
  47. struct top_dim<geometry_collection_tag> : std::integral_constant<int, -1> {};
  48. } // namespace core_dispatch
  49. #endif
  50. /*!
  51. \brief Meta-function returning the topological dimension of a geometry
  52. \details The topological dimension defines a point as 0-dimensional,
  53. a linestring as 1-dimensional,
  54. and a ring or polygon as 2-dimensional.
  55. \see http://www.math.okstate.edu/mathdept/dynamics/lecnotes/node36.html
  56. \ingroup core
  57. */
  58. template <typename Geometry>
  59. struct topological_dimension
  60. : core_dispatch::top_dim<typename tag<Geometry>::type> {};
  61. }} // namespace boost::geometry
  62. #endif // BOOST_GEOMETRY_CORE_TOPOLOGICAL_DIMENSION_HPP