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// Boost.Geometry (aka GGL, Generic Geometry Library)
// Copyright (c) 2014-2015, 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_LINEAR_HPP
#define BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_VALID_LINEAR_HPP
#include <cstddef>
#include <boost/range.hpp>
#include <boost/geometry/core/closure.hpp>
#include <boost/geometry/core/point_type.hpp>
#include <boost/geometry/core/tags.hpp>
#include <boost/geometry/util/condition.hpp>
#include <boost/geometry/util/range.hpp>
#include <boost/geometry/algorithms/equals.hpp>
#include <boost/geometry/algorithms/validity_failure_type.hpp>
#include <boost/geometry/algorithms/detail/check_iterator_range.hpp>
#include <boost/geometry/algorithms/detail/is_valid/has_invalid_coordinate.hpp>
#include <boost/geometry/algorithms/detail/is_valid/has_spikes.hpp>
#include <boost/geometry/algorithms/detail/num_distinct_consecutive_points.hpp>
#include <boost/geometry/algorithms/dispatch/is_valid.hpp>
namespace boost { namespace geometry
{
#ifndef DOXYGEN_NO_DETAIL
namespace detail { namespace is_valid
{
template <typename Linestring>
struct is_valid_linestring
{
template <typename VisitPolicy>
static inline bool apply(Linestring const& linestring,
VisitPolicy& visitor)
{
if (has_invalid_coordinate<Linestring>::apply(linestring, visitor))
{
return false;
}
if (boost::size(linestring) < 2)
{
return visitor.template apply<failure_few_points>();
}
std::size_t num_distinct = detail::num_distinct_consecutive_points
<
Linestring,
3u,
true,
not_equal_to<typename point_type<Linestring>::type>
>::apply(linestring);
if (num_distinct < 2u)
{
return
visitor.template apply<failure_wrong_topological_dimension>();
}
if (num_distinct == 2u)
{
return visitor.template apply<no_failure>();
}
return ! has_spikes<Linestring, closed>::apply(linestring, visitor);
}
};
}} // namespace detail::is_valid
#endif // DOXYGEN_NO_DETAIL
#ifndef DOXYGEN_NO_DISPATCH
namespace dispatch
{
// A linestring is a curve.
// A curve is 1-dimensional so it has to have at least two distinct
// points.
// A curve is simple if it does not pass through the same point twice,
// with the possible exception of its two endpoints
//
// There is an option here as to whether spikes are allowed for linestrings;
// here we pass this as an additional template parameter: allow_spikes
// If allow_spikes is set to true, spikes are allowed, false otherwise.
// By default, spikes are disallowed
//
// Reference: OGC 06-103r4 (6.1.6.1)
template <typename Linestring, bool AllowEmptyMultiGeometries>
struct is_valid
<
Linestring, linestring_tag, AllowEmptyMultiGeometries
> : detail::is_valid::is_valid_linestring<Linestring>
{};
// A MultiLinestring is a MultiCurve
// A MultiCurve is simple if all of its elements are simple and the
// only intersections between any two elements occur at Points that
// are on the boundaries of both elements.
//
// Reference: OGC 06-103r4 (6.1.8.1; Fig. 9)
template <typename MultiLinestring, bool AllowEmptyMultiGeometries>
class is_valid
<
MultiLinestring, multi_linestring_tag, AllowEmptyMultiGeometries
>
{
private:
template <typename VisitPolicy>
struct per_linestring
{
per_linestring(VisitPolicy& policy) : m_policy(policy) {}
template <typename Linestring>
inline bool apply(Linestring const& linestring) const
{
return detail::is_valid::is_valid_linestring
<
Linestring
>::apply(linestring, m_policy);
}
VisitPolicy& m_policy;
};
public:
template <typename VisitPolicy>
static inline bool apply(MultiLinestring const& multilinestring,
VisitPolicy& visitor)
{
if (BOOST_GEOMETRY_CONDITION(
AllowEmptyMultiGeometries && boost::empty(multilinestring)))
{
return visitor.template apply<no_failure>();
}
return detail::check_iterator_range
<
per_linestring<VisitPolicy>,
false // do not check for empty multilinestring (done above)
>::apply(boost::begin(multilinestring),
boost::end(multilinestring),
per_linestring<VisitPolicy>(visitor));
}
};
} // namespace dispatch
#endif // DOXYGEN_NO_DISPATCH
}} // namespace boost::geometry
#endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_VALID_LINEAR_HPP
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