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- // Boost.Geometry (aka GGL, Generic Geometry Library)
- // Copyright (c) 2007-2015 Barend Gehrels, Amsterdam, the Netherlands.
- // Copyright (c) 2008-2015 Bruno Lalande, Paris, France.
- // Copyright (c) 2009-2015 Mateusz Loskot, London, UK.
- // Copyright (c) 2013-2015 Adam Wulkiewicz, Lodz, Poland.
- // This file was modified by Oracle on 2015, 2017, 2019.
- // Modifications copyright (c) 2015-2019 Oracle and/or its affiliates.
- // Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle
- // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
- // Use, modification and distribution is subject to the Boost Software License,
- // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
- // http://www.boost.org/LICENSE_1_0.txt)
- #ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_POINT_IS_EQUAL_OR_SPIKE_HPP
- #define BOOST_GEOMETRY_ALGORITHMS_DETAIL_POINT_IS_EQUAL_OR_SPIKE_HPP
- #include <boost/geometry/algorithms/detail/direction_code.hpp>
- #include <boost/geometry/algorithms/detail/recalculate.hpp>
- #include <boost/geometry/core/cs.hpp>
- #include <boost/geometry/policies/robustness/robust_point_type.hpp>
- #include <boost/geometry/strategies/side.hpp>
- #include <boost/geometry/util/condition.hpp>
- #include <boost/geometry/util/math.hpp>
- namespace boost { namespace geometry
- {
- #ifndef DOXYGEN_NO_DETAIL
- namespace detail
- {
- // Checks if a point ("last_point") causes a spike w.r.t.
- // the specified two other points (segment_a, segment_b)
- //
- // x-------x------x
- // a lp b
- //
- // Above, lp generates a spike w.r.t. segment(a,b)
- // So specify last point first, then (a,b)
- // The segment's orientation does matter: if lp is to the right of b
- // no spike is reported
- template
- <
- typename Point1, typename Point2, typename Point3,
- typename SideStrategy
- >
- inline bool point_is_spike_or_equal(Point1 const& last_point, // prev | back
- Point2 const& segment_a, // next | back - 2
- Point3 const& segment_b, // curr | back - 1 | spike's vertex
- SideStrategy const& strategy)
- {
- typedef typename SideStrategy::cs_tag cs_tag;
- int const side = strategy.apply(segment_a, segment_b, last_point);
- if (side == 0)
- {
- // Last point is collinear w.r.t previous segment.
- return direction_code<cs_tag>(segment_a, segment_b, last_point) < 1;
- }
- return false;
- }
- template
- <
- typename Point1,
- typename Point2,
- typename Point3,
- typename SideStrategy,
- typename RobustPolicy
- >
- inline bool point_is_spike_or_equal(Point1 const& last_point,
- Point2 const& segment_a,
- Point3 const& segment_b,
- SideStrategy const& strategy,
- RobustPolicy const& robust_policy)
- {
- if (point_is_spike_or_equal(last_point, segment_a, segment_b, strategy))
- {
- return true;
- }
- if (BOOST_GEOMETRY_CONDITION(! RobustPolicy::enabled))
- {
- return false;
- }
- // Try using specified robust policy
- typedef typename geometry::robust_point_type
- <
- Point1,
- RobustPolicy
- >::type robust_point_type;
- robust_point_type last_point_rob, segment_a_rob, segment_b_rob;
- geometry::recalculate(last_point_rob, last_point, robust_policy);
- geometry::recalculate(segment_a_rob, segment_a, robust_policy);
- geometry::recalculate(segment_b_rob, segment_b, robust_policy);
- return point_is_spike_or_equal
- (
- last_point_rob,
- segment_a_rob,
- segment_b_rob,
- strategy
- );
- }
- template
- <
- typename Point1,
- typename Point2,
- typename Point3,
- typename SideStrategy,
- typename RobustPolicy
- >
- inline bool point_is_collinear(Point1 const& last_point,
- Point2 const& segment_a,
- Point3 const& segment_b,
- SideStrategy const& strategy,
- RobustPolicy const& robust_policy)
- {
- int const side = strategy.apply(segment_a, segment_b, last_point);
- if (side == 0)
- {
- return true;
- }
- // This part (or whole method, because it is then trivial)
- // will be removed after rescaling
- if (BOOST_GEOMETRY_CONDITION(! RobustPolicy::enabled))
- {
- return false;
- }
- // Redo, using specified robust policy
- typedef typename geometry::robust_point_type
- <
- Point1,
- RobustPolicy
- >::type robust_point_type;
- robust_point_type last_point_rob, segment_a_rob, segment_b_rob;
- geometry::recalculate(last_point_rob, last_point, robust_policy);
- geometry::recalculate(segment_a_rob, segment_a, robust_policy);
- geometry::recalculate(segment_b_rob, segment_b, robust_policy);
- int const side_rob = strategy.apply(segment_a_rob, segment_b_rob, last_point_rob);
- return side_rob == 0;
- }
- //! Version with intuitive order (A, B, C). The original order was
- //! unclear (C, A, B). It was used in a different way in has_spikes.
- //! On longer term the C,A,B version can be deprecated
- template
- <
- typename Point1,
- typename Point2,
- typename Point3,
- typename SideStrategy
- >
- inline bool is_spike_or_equal(Point1 const& a,
- Point2 const& b,
- Point3 const& c,
- SideStrategy const& strategy)
- {
- return point_is_spike_or_equal(c, a, b, strategy);
- }
- } // namespace detail
- #endif
- }} // namespace boost::geometry
- #endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_POINT_IS_EQUAL_OR_SPIKE_HPP
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