ceph/src/boost/boost/geometry/algorithms/detail/is_valid/segment.hpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2
   3 // Copyright (c) 2014-2019, Oracle and/or its affiliates.
   4
   5 // Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle
   6 // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
   7
   8 // Licensed under the Boost Software License version 1.0.
   9 // http://www.boost.org/users/license.html
  10
  11 #ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_VALID_SEGMENT_HPP
  12 #define BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_VALID_SEGMENT_HPP
  13
  14 #include <boost/core/ignore_unused.hpp>
  15
  16 #include <boost/geometry/core/point_type.hpp>
  17 #include <boost/geometry/core/tags.hpp>
  18
  19 #include <boost/geometry/algorithms/assign.hpp>
  20 #include <boost/geometry/algorithms/validity_failure_type.hpp>
  21 #include <boost/geometry/algorithms/detail/equals/point_point.hpp>
  22 #include <boost/geometry/algorithms/detail/is_valid/has_invalid_coordinate.hpp>
  23 #include <boost/geometry/algorithms/dispatch/is_valid.hpp>
  24
  25
  26 namespace boost { namespace geometry
  27 {
  28
  29
  30
  31 #ifndef DOXYGEN_NO_DISPATCH
  32 namespace dispatch
  33 {
  34
  35
  36 // A segment is a curve.
  37 // A curve is simple if it does not pass through the same point twice,
  38 // with the possible exception of its two endpoints
  39 // A curve is 1-dimensional, hence we have to check is the two
  40 // endpoints of the segment coincide, since in this case it is
  41 // 0-dimensional.
  42 //
  43 // Reference: OGC 06-103r4 (6.1.6.1)
  44 template <typename Segment>
  45 struct is_valid<Segment, segment_tag>
  46 {
  47     template <typename VisitPolicy, typename Strategy>
  48     static inline bool apply(Segment const& segment, VisitPolicy& visitor, Strategy const&)
  49     {
  50         typedef typename Strategy::equals_point_point_strategy_type eq_pp_strategy_type;
  51
  52         boost::ignore_unused(visitor);
  53
  54         typename point_type<Segment>::type p[2];
  55         detail::assign_point_from_index<0>(segment, p[0]);
  56         detail::assign_point_from_index<1>(segment, p[1]);
  57
  58         if (detail::is_valid::has_invalid_coordinate
  59                 <
  60                     Segment
  61                 >::apply(segment, visitor))
  62         {
  63             return false;
  64         }
  65         else if (! geometry::detail::equals::equals_point_point(
  66                         p[0], p[1], eq_pp_strategy_type()))
  67         {
  68             return visitor.template apply<no_failure>();
  69         }
  70         else
  71         {
  72             return
  73                 visitor.template apply<failure_wrong_topological_dimension>();
  74         }
  75     }
  76 };
  77
  78
  79 } // namespace dispatch
  80 #endif // DOXYGEN_NO_DISPATCH
  81
  82
  83 }} // namespace boost::geometry
  84
  85
  86 #endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_VALID_SEGMENT_HPP