algorithms/detail/has_self_intersections.hpp

0001 // Boost.Geometry (aka GGL, Generic Geometry Library)
0002
0003 // Copyright (c) 2011-2012 Barend Gehrels, Amsterdam, the Netherlands.
0004 // Copyright (c) 2017 Adam Wulkiewicz, Lodz, Poland.
0005
0006 // This file was modified by Oracle on 2017-2024.
0007 // Modifications copyright (c) 2017-2024 Oracle and/or its affiliates.
0008 // Contributed and/or modified by Vissarion Fysikopoulos, on behalf of Oracle
0009 // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
0010
0011 // Use, modification and distribution is subject to the Boost Software License,
0012 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
0013 // http://www.boost.org/LICENSE_1_0.txt)
0014
0015 #ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_HAS_SELF_INTERSECTIONS_HPP
0016 #define BOOST_GEOMETRY_ALGORITHMS_DETAIL_HAS_SELF_INTERSECTIONS_HPP
0017
0018 #include <deque>
0019
0020 #include <boost/range/begin.hpp>
0021 #include <boost/range/end.hpp>
0022 #include <boost/throw_exception.hpp>
0023
0024 #include <boost/geometry/core/point_type.hpp>
0025 #include <boost/geometry/algorithms/detail/overlay/turn_info.hpp>
0026 #include <boost/geometry/algorithms/detail/overlay/get_turns.hpp>
0027 #include <boost/geometry/algorithms/detail/overlay/self_turn_points.hpp>
0028
0029 #include <boost/geometry/policies/disjoint_interrupt_policy.hpp>
0030
0031 #ifdef BOOST_GEOMETRY_DEBUG_HAS_SELF_INTERSECTIONS
0032 #  include <boost/geometry/algorithms/detail/overlay/debug_turn_info.hpp>
0033 #  include <boost/geometry/io/dsv/write.hpp>
0034 #endif
0035
0036
0037 namespace boost { namespace geometry
0038 {
0039
0040
0041 #if ! defined(BOOST_GEOMETRY_OVERLAY_NO_THROW)
0042
0043 /*!
0044 \brief Overlay Invalid Input Exception
0045 \ingroup overlay
0046 \details The overlay_invalid_input_exception is thrown at invalid input
0047  */
0048 class overlay_invalid_input_exception : public geometry::exception
0049 {
0050 public:
0051
0052     inline overlay_invalid_input_exception() {}
0053
0054     char const* what() const noexcept override
0055     {
0056         return "Boost.Geometry Overlay invalid input exception";
0057     }
0058 };
0059
0060 #endif
0061
0062
0063 #ifndef DOXYGEN_NO_DETAIL
0064 namespace detail { namespace overlay
0065 {
0066
0067
0068 template <typename Geometry, typename Strategy>
0069 inline bool has_self_intersections(Geometry const& geometry,
0070         Strategy const& strategy,
0071         bool throw_on_self_intersection = true)
0072 {
0073     using point_type = point_type_t<Geometry>;
0074     using turn_info = turn_info
0075     <
0076         point_type,
0077         typename segment_ratio_type<point_type>::type
0078     >;
0079     std::deque<turn_info> turns;
0080     detail::disjoint::disjoint_interrupt_policy policy;
0081
0082     detail::self_get_turn_points::self_turns
0083         <
0084             false,
0085             detail::overlay::assign_null_policy
0086         >(geometry, strategy, turns, policy, 0, false);
0087
0088 #ifdef BOOST_GEOMETRY_DEBUG_HAS_SELF_INTERSECTIONS
0089     bool first = true;
0090 #endif
0091     for (auto const& info : turns)
0092     {
0093         bool const both_union_turn =
0094             info.operations[0].operation == detail::overlay::operation_union
0095             && info.operations[1].operation == detail::overlay::operation_union;
0096         bool const both_intersection_turn =
0097             info.operations[0].operation == detail::overlay::operation_intersection
0098             && info.operations[1].operation == detail::overlay::operation_intersection;
0099
0100         bool const valid = (both_union_turn || both_intersection_turn)
0101             && (info.method == detail::overlay::method_touch
0102                 || info.method == detail::overlay::method_touch_interior);
0103
0104         if (! valid)
0105         {
0106 #ifdef BOOST_GEOMETRY_DEBUG_HAS_SELF_INTERSECTIONS
0107             if (first)
0108             {
0109                 std::cout << "turn points: " << std::endl;
0110                 first = false;
0111             }
0112             std::cout << method_char(info.method);
0113             for (int i = 0; i < 2; i++)
0114             {
0115                 std::cout << " " << operation_char(info.operations[i].operation);
0116                 std::cout << " " << info.operations[i].seg_id;
0117             }
0118             std::cout << " " << geometry::dsv(info.point) << std::endl;
0119 #endif
0120
0121 #if ! defined(BOOST_GEOMETRY_OVERLAY_NO_THROW)
0122             if (throw_on_self_intersection)
0123             {
0124                 BOOST_THROW_EXCEPTION(overlay_invalid_input_exception());
0125             }
0126 #endif
0127             return true;
0128         }
0129
0130     }
0131     return false;
0132 }
0133
0134
0135 }} // namespace detail::overlay
0136 #endif // DOXYGEN_NO_DETAIL
0137
0138
0139 }} // namespace boost::geometry
0140
0141
0142 #endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_HAS_SELF_INTERSECTIONS_HPP
0143