1 // Boost.Geometry (aka GGL, Generic Geometry Library)
2 
3 // Copyright (c) 2014, Oracle and/or its affiliates.
4 
5 // Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle
6 
7 // Licensed under the Boost Software License version 1.0.
8 // http://www.boost.org/users/license.html
9 
10 #ifndef BOOST_GEOMETRY_ALGORITHMS_POLICIES_PREDICATE_BASED_INTERRUPT_POLICY_HPP
11 #define BOOST_GEOMETRY_ALGORITHMS_POLICIES_PREDICATE_BASED_INTERRUPT_POLICY_HPP
12 
13 #include <boost/range.hpp>
14 
15 #include <boost/geometry/algorithms/detail/check_iterator_range.hpp>
16 
17 
18 namespace boost { namespace geometry
19 {
20 
21 
22 #ifndef DOXYGEN_NO_DETAIL
23 namespace detail { namespace overlay
24 {
25 
26 
27 template
28 <
29     typename IsAcceptableTurnPredicate,
30     bool AllowEmptyTurnRange = true // by default, allow an empty turn range
31 >
32 struct stateless_predicate_based_interrupt_policy
33 {
34     static bool const enabled = true;
35     bool has_intersections; // set to true if there is at least one
36                             // unacceptable turn
37 
stateless_predicate_based_interrupt_policyboost::geometry::detail::overlay::stateless_predicate_based_interrupt_policy38     inline stateless_predicate_based_interrupt_policy()
39         : has_intersections(false)
40     {}
41 
42     template <typename Range>
applyboost::geometry::detail::overlay::stateless_predicate_based_interrupt_policy43     inline bool apply(Range const& range)
44     {
45         // if there is at least one unacceptable turn in the range, return false
46         has_intersections = !detail::check_iterator_range
47             <
48                 IsAcceptableTurnPredicate,
49                 AllowEmptyTurnRange
50             >::apply(boost::begin(range), boost::end(range));
51 
52         return has_intersections;
53     }
54 };
55 
56 
57 
58 
59 template
60 <
61     typename IsAcceptableTurnPredicate,
62     bool AllowEmptyTurnRange = true // by default, allow an empty turn range
63 >
64 struct predicate_based_interrupt_policy
65 {
66     static bool const enabled = true;
67     bool has_intersections; // set to true if there is at least one
68                             // unacceptable turn
69     IsAcceptableTurnPredicate const& m_predicate;
70 
71     inline
predicate_based_interrupt_policyboost::geometry::detail::overlay::predicate_based_interrupt_policy72     predicate_based_interrupt_policy(IsAcceptableTurnPredicate const& predicate)
73         : has_intersections(false)
74         , m_predicate(predicate)
75     {}
76 
77     template <typename Range>
applyboost::geometry::detail::overlay::predicate_based_interrupt_policy78     inline bool apply(Range const& range)
79     {
80         // if there is at least one unacceptable turn in the range, return false
81         has_intersections = !detail::check_iterator_range
82             <
83                 IsAcceptableTurnPredicate,
84                 AllowEmptyTurnRange
85             >::apply(boost::begin(range), boost::end(range), m_predicate);
86 
87         return has_intersections;
88     }
89 };
90 
91 
92 
93 
94 }} // namespace detail::overlay
95 #endif // DOXYGEN_NO_DETAIL
96 
97 
98 }} // namespace boost::geometry
99 
100 
101 #endif // BOOST_GEOMETRY_ALGORITHMS_POLICIES_PREDICATE_BASED_INTERRUPT_POLICY_HPP
102