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// Boost.Geometry (aka GGL, Generic Geometry Library)
// Copyright (c) 2014-2017, 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
// Licensed under the Boost Software License version 1.0.
// http://www.boost.org/users/license.html
#ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_VALID_SEGMENT_HPP
#define BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_VALID_SEGMENT_HPP
#include <boost/core/ignore_unused.hpp>
#include <boost/geometry/core/point_type.hpp>
#include <boost/geometry/core/tags.hpp>
#include <boost/geometry/algorithms/assign.hpp>
#include <boost/geometry/algorithms/equals.hpp>
#include <boost/geometry/algorithms/validity_failure_type.hpp>
#include <boost/geometry/algorithms/detail/is_valid/has_invalid_coordinate.hpp>
#include <boost/geometry/algorithms/dispatch/is_valid.hpp>
namespace boost { namespace geometry
{
#ifndef DOXYGEN_NO_DISPATCH
namespace dispatch
{
// A segment is a curve.
// A curve is simple if it does not pass through the same point twice,
// with the possible exception of its two endpoints
// A curve is 1-dimensional, hence we have to check is the two
// endpoints of the segment coincide, since in this case it is
// 0-dimensional.
//
// Reference: OGC 06-103r4 (6.1.6.1)
template <typename Segment>
struct is_valid<Segment, segment_tag>
{
template <typename VisitPolicy, typename Strategy>
static inline bool apply(Segment const& segment, VisitPolicy& visitor, Strategy const&)
{
boost::ignore_unused(visitor);
typename point_type<Segment>::type p[2];
detail::assign_point_from_index<0>(segment, p[0]);
detail::assign_point_from_index<1>(segment, p[1]);
if (detail::is_valid::has_invalid_coordinate
<
Segment
>::apply(segment, visitor))
{
return false;
}
else if (! geometry::equals(p[0], p[1]))
{
return visitor.template apply<no_failure>();
}
else
{
return
visitor.template apply<failure_wrong_topological_dimension>();
}
}
};
} // namespace dispatch
#endif // DOXYGEN_NO_DISPATCH
}} // namespace boost::geometry
#endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_VALID_SEGMENT_HPP
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