detail/is_valid/has_valid_self_turns.hpp

0001 // Boost.Geometry (aka GGL, Generic Geometry Library)
0002
0003 // Copyright (c) 2014-2024, Oracle and/or its affiliates.
0004 // Contributed and/or modified by Vissarion Fysikopoulos, on behalf of Oracle
0005 // Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle
0006 // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
0007
0008 // Licensed under the Boost Software License version 1.0.
0009 // http://www.boost.org/users/license.html
0010
0011 #ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_VALID_HAS_VALID_SELF_TURNS_HPP
0012 #define BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_VALID_HAS_VALID_SELF_TURNS_HPP
0013
0014 #include <vector>
0015
0016 #include <boost/core/ignore_unused.hpp>
0017 #include <boost/range/empty.hpp>
0018
0019 #include <boost/geometry/algorithms/detail/is_valid/is_acceptable_turn.hpp>
0020 #include <boost/geometry/algorithms/detail/overlay/get_turn_info.hpp>
0021 #include <boost/geometry/algorithms/detail/overlay/turn_info.hpp>
0022 #include <boost/geometry/algorithms/detail/overlay/self_turn_points.hpp>
0023 #include <boost/geometry/algorithms/validity_failure_type.hpp>
0024
0025 #include <boost/geometry/core/assert.hpp>
0026 #include <boost/geometry/core/point_type.hpp>
0027
0028 #include <boost/geometry/policies/predicate_based_interrupt_policy.hpp>
0029
0030 namespace boost { namespace geometry
0031 {
0032
0033
0034 #ifndef DOXYGEN_NO_DETAIL
0035 namespace detail { namespace is_valid
0036 {
0037
0038
0039 template
0040 <
0041     typename Geometry,
0042     typename CSTag // TODO: remove
0043 >
0044 class has_valid_self_turns
0045 {
0046 private:
0047     using point_type = point_type_t<Geometry>;
0048
0049 public:
0050     using turn_type = detail::overlay::turn_info
0051         <
0052             point_type,
0053             typename segment_ratio_type<point_type>::type
0054         >;
0055
0056     // returns true if all turns are valid
0057     template <typename Turns, typename VisitPolicy, typename Strategy>
0058     static inline bool apply(Geometry const& geometry,
0059                              Turns& turns,
0060                              VisitPolicy& visitor,
0061                              Strategy const& strategy)
0062     {
0063         boost::ignore_unused(visitor);
0064
0065         detail::overlay::stateless_predicate_based_interrupt_policy
0066             <
0067                 is_acceptable_turn<Geometry>
0068             > interrupt_policy;
0069
0070         // Calculate self-turns, skipping adjacent segments
0071         detail::self_get_turn_points::self_turns
0072             <
0073                 false, detail::overlay::assign_null_policy
0074             >(geometry, strategy, turns, interrupt_policy,
0075               0, true);
0076
0077         if (interrupt_policy.has_intersections)
0078         {
0079             BOOST_GEOMETRY_ASSERT(! boost::empty(turns));
0080             return visitor.template apply<failure_self_intersections>(turns);
0081         }
0082         else
0083         {
0084             return visitor.template apply<no_failure>();
0085         }
0086     }
0087
0088     // returns true if all turns are valid
0089     template <typename VisitPolicy, typename Strategy>
0090     static inline bool apply(Geometry const& geometry, VisitPolicy& visitor, Strategy const& strategy)
0091     {
0092         std::vector<turn_type> turns;
0093         return apply(geometry, turns, visitor, strategy);
0094     }
0095 };
0096
0097
0098 }} // namespace detail::is_valid
0099 #endif // DOXYGEN_NO_DETAIL
0100
0101 }} // namespace boost::geometry
0102
0103 #endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_VALID_HAS_VALID_SELF_TURNS_HPP