1 // Boost.Geometry (aka GGL, Generic Geometry Library) 2 3 // Copyright (c) 2014, Oracle and/or its affiliates. 4 5 // Licensed under the Boost Software License version 1.0. 6 // http://www.boost.org/users/license.html 7 8 // Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle 9 10 11 #ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_TURNS_FILTER_CONTINUE_TURNS_HPP 12 #define BOOST_GEOMETRY_ALGORITHMS_DETAIL_TURNS_FILTER_CONTINUE_TURNS_HPP 13 14 #include <algorithm> 15 #include <boost/geometry/algorithms/detail/overlay/turn_info.hpp> 16 17 namespace boost { namespace geometry 18 { 19 20 namespace detail { namespace turns 21 { 22 23 24 template <typename Turns, bool Enable> 25 struct filter_continue_turns 26 { applyboost::geometry::detail::turns::filter_continue_turns27 static inline void apply(Turns&) {} 28 }; 29 30 31 template <typename Turns> 32 class filter_continue_turns<Turns, true> 33 { 34 private: 35 class IsContinueTurn 36 { 37 private: 38 template <typename Operation> is_continue_or_opposite(Operation const & operation) const39 inline bool is_continue_or_opposite(Operation const& operation) const 40 { 41 return operation == detail::overlay::operation_continue 42 || operation == detail::overlay::operation_opposite; 43 } 44 45 public: 46 template <typename Turn> operator ()(Turn const & turn) const47 bool operator()(Turn const& turn) const 48 { 49 if ( turn.method != detail::overlay::method_collinear 50 && turn.method != detail::overlay::method_equal ) 51 { 52 return false; 53 } 54 55 return is_continue_or_opposite(turn.operations[0].operation) 56 && is_continue_or_opposite(turn.operations[1].operation); 57 } 58 }; 59 60 61 public: apply(Turns & turns)62 static inline void apply(Turns& turns) 63 { 64 turns.erase( std::remove_if(turns.begin(), turns.end(), 65 IsContinueTurn()), 66 turns.end() 67 ); 68 } 69 }; 70 71 72 }} // namespace detail::turns 73 74 }} // namespect boost::geometry 75 76 77 78 #endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_TURNS_FILTER_CONTINUE_TURNS_HPP 79