reverse.hpp 2.9 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125
  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. // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
  6. // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
  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. #ifndef BOOST_GEOMETRY_ALGORITHMS_REVERSE_HPP
  11. #define BOOST_GEOMETRY_ALGORITHMS_REVERSE_HPP
  12. #include <algorithm>
  13. #include <boost/range.hpp>
  14. #include <boost/typeof/typeof.hpp>
  15. #include <boost/geometry/core/interior_rings.hpp>
  16. #include <boost/geometry/geometries/concepts/check.hpp>
  17. namespace boost { namespace geometry
  18. {
  19. #ifndef DOXYGEN_NO_DETAIL
  20. namespace detail { namespace reverse
  21. {
  22. struct range_reverse
  23. {
  24. template <typename Range>
  25. static inline void apply(Range& range)
  26. {
  27. std::reverse(boost::begin(range), boost::end(range));
  28. }
  29. };
  30. struct polygon_reverse: private range_reverse
  31. {
  32. template <typename Polygon>
  33. static inline void apply(Polygon& polygon)
  34. {
  35. typedef typename geometry::ring_type<Polygon>::type ring_type;
  36. range_reverse::apply(exterior_ring(polygon));
  37. typename interior_return_type<Polygon>::type rings
  38. = interior_rings(polygon);
  39. for (BOOST_AUTO_TPL(it, boost::begin(rings)); it != boost::end(rings); ++it)
  40. {
  41. range_reverse::apply(*it);
  42. }
  43. }
  44. };
  45. }} // namespace detail::reverse
  46. #endif // DOXYGEN_NO_DETAIL
  47. #ifndef DOXYGEN_NO_DISPATCH
  48. namespace dispatch
  49. {
  50. template <typename Geometry, typename Tag = typename tag<Geometry>::type>
  51. struct reverse
  52. {
  53. static inline void apply(Geometry&)
  54. {}
  55. };
  56. template <typename Ring>
  57. struct reverse<Ring, ring_tag>
  58. : detail::reverse::range_reverse
  59. {};
  60. template <typename LineString>
  61. struct reverse<LineString, linestring_tag>
  62. : detail::reverse::range_reverse
  63. {};
  64. template <typename Polygon>
  65. struct reverse<Polygon, polygon_tag>
  66. : detail::reverse::polygon_reverse
  67. {};
  68. } // namespace dispatch
  69. #endif
  70. /*!
  71. \brief Reverses the points within a geometry
  72. \details Generic function to reverse a geometry. It resembles the std::reverse
  73. functionality, but it takes the geometry type into account. Only for a ring
  74. or for a linestring it is the same as the std::reverse.
  75. \ingroup reverse
  76. \tparam Geometry \tparam_geometry
  77. \param geometry \param_geometry which will be reversed
  78. \qbk{[include reference/algorithms/reverse.qbk]}
  79. */
  80. template <typename Geometry>
  81. inline void reverse(Geometry& geometry)
  82. {
  83. concept::check<Geometry>();
  84. dispatch::reverse<Geometry>::apply(geometry);
  85. }
  86. }} // namespace boost::geometry
  87. #endif // BOOST_GEOMETRY_ALGORITHMS_REVERSE_HPP