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// Boost.Geometry (aka GGL, Generic Geometry Library)
// Copyright (c) 2014-2021, 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_HAS_SPIKES_HPP
#define BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_VALID_HAS_SPIKES_HPP
#include <algorithm>
#include <boost/core/ignore_unused.hpp>
#include <boost/range/begin.hpp>
#include <boost/range/end.hpp>
#include <boost/range/rbegin.hpp>
#include <boost/range/rend.hpp>
#include <boost/geometry/algorithms/detail/equals/point_point.hpp>
#include <boost/geometry/algorithms/validity_failure_type.hpp>
#include <boost/geometry/algorithms/detail/point_is_spike_or_equal.hpp>
#include <boost/geometry/core/assert.hpp>
#include <boost/geometry/core/point_type.hpp>
#include <boost/geometry/core/tag.hpp>
#include <boost/geometry/core/tags.hpp>
#include <boost/geometry/io/dsv/write.hpp>
#include <boost/geometry/policies/is_valid/default_policy.hpp>
#include <boost/geometry/util/range.hpp>
#include <boost/geometry/util/type_traits.hpp>
#include <boost/geometry/views/closeable_view.hpp>
namespace boost { namespace geometry
{
#ifndef DOXYGEN_NO_DETAIL
namespace detail { namespace is_valid
{
template <typename Range>
struct has_spikes
{
template <typename Iterator, typename Strategy>
static inline Iterator find_different_from_first(Iterator first,
Iterator last,
Strategy const& strategy)
{
if (first == last)
{
return last;
}
auto const& front = *first;
++first;
return std::find_if(first, last, [&](auto const& pt) {
return ! equals::equals_point_point(pt, front, strategy);
});
}
template <typename View, typename VisitPolicy, typename Strategy>
static inline bool apply_at_closure(View const& view, VisitPolicy& visitor,
Strategy const& strategy,
bool is_linear)
{
boost::ignore_unused(visitor);
auto cur = boost::begin(view);
auto prev = find_different_from_first(boost::rbegin(view),
boost::rend(view),
strategy);
auto next = find_different_from_first(cur, boost::end(view), strategy);
if (detail::is_spike_or_equal(*next, *cur, *prev, strategy.side()))
{
return ! visitor.template apply<failure_spikes>(is_linear, *cur);
}
else
{
return ! visitor.template apply<no_failure>();
}
}
template <typename VisitPolicy, typename Strategy>
static inline bool apply(Range const& range, VisitPolicy& visitor,
Strategy const& strategy)
{
boost::ignore_unused(visitor);
bool const is_linestring = util::is_linestring<Range>::value;
detail::closed_view<Range const> const view(range);
auto prev = boost::begin(view);
auto const end = boost::end(view);
auto cur = find_different_from_first(prev, boost::end(view), strategy);
if (cur == end)
{
// the range has only one distinct point, so it
// cannot have a spike
return ! visitor.template apply<no_failure>();
}
auto next = find_different_from_first(cur, boost::end(view), strategy);
if (next == end)
{
// the range has only two distinct points, so it
// cannot have a spike
return ! visitor.template apply<no_failure>();
}
while (next != end)
{
// Verify spike. TODO: this is a reverse order from expected
// in is_spike_or_equal, but this order calls the side
// strategy in the way to correctly detect the spikes,
// also in geographic cases going over the pole
if (detail::is_spike_or_equal(*next, *cur, *prev, strategy.side()))
{
return ! visitor.template apply<failure_spikes>(is_linestring, *cur);
}
prev = cur;
cur = next;
next = find_different_from_first(cur, boost::end(view), strategy);
}
if (equals::equals_point_point(range::front(view), range::back(view),
strategy))
{
return apply_at_closure(view, visitor, strategy, is_linestring);
}
return ! visitor.template apply<no_failure>();
}
};
}} // namespace detail::is_valid
#endif // DOXYGEN_NO_DETAIL
}} // namespace boost::geometry
#endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_VALID_HAS_SPIKES_HPP
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