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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
// Licensed under the Boost Software License version 1.0.
// http://www.boost.org/users/license.html
#ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_SIMPLE_LINEAR_HPP
#define BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_SIMPLE_LINEAR_HPP
#include <algorithm>
#include <deque>
#include <boost/assert.hpp>
#include <boost/range.hpp>
#include <boost/geometry/core/closure.hpp>
#include <boost/geometry/core/coordinate_type.hpp>
#include <boost/geometry/core/point_type.hpp>
#include <boost/geometry/core/tag.hpp>
#include <boost/geometry/core/tags.hpp>
#include <boost/geometry/util/range.hpp>
#include <boost/geometry/policies/predicate_based_interrupt_policy.hpp>
#include <boost/geometry/policies/robustness/no_rescale_policy.hpp>
#include <boost/geometry/policies/robustness/segment_ratio.hpp>
#include <boost/geometry/algorithms/equals.hpp>
#include <boost/geometry/algorithms/intersects.hpp>
#include <boost/geometry/algorithms/not_implemented.hpp>
#include <boost/geometry/algorithms/detail/check_iterator_range.hpp>
#include <boost/geometry/algorithms/detail/signed_index_type.hpp>
#include <boost/geometry/algorithms/detail/disjoint/linear_linear.hpp>
#include <boost/geometry/algorithms/detail/overlay/get_turn_info.hpp>
#include <boost/geometry/algorithms/detail/overlay/turn_info.hpp>
#include <boost/geometry/algorithms/detail/overlay/self_turn_points.hpp>
#include <boost/geometry/algorithms/detail/is_valid/has_duplicates.hpp>
#include <boost/geometry/algorithms/detail/is_valid/has_spikes.hpp>
#include <boost/geometry/algorithms/detail/is_simple/debug_print_boundary_points.hpp>
#include <boost/geometry/algorithms/detail/is_simple/failure_policy.hpp>
#include <boost/geometry/algorithms/detail/is_valid/debug_print_turns.hpp>
#include <boost/geometry/algorithms/dispatch/is_simple.hpp>
namespace boost { namespace geometry
{
#ifndef DOXYGEN_NO_DETAIL
namespace detail { namespace is_simple
{
template <typename Turn>
inline bool check_segment_indices(Turn const& turn,
signed_index_type last_index)
{
return
(turn.operations[0].seg_id.segment_index == 0
&& turn.operations[1].seg_id.segment_index == last_index)
||
(turn.operations[0].seg_id.segment_index == 0
&& turn.operations[1].seg_id.segment_index == last_index);
}
template <typename Geometry, typename Tag = typename tag<Geometry>::type>
class is_acceptable_turn
: not_implemented<Geometry>
{};
template <typename Linestring>
class is_acceptable_turn<Linestring, linestring_tag>
{
public:
is_acceptable_turn(Linestring const& linestring)
: m_linestring(linestring)
, m_is_closed(geometry::equals(range::front(linestring),
range::back(linestring)))
{}
template <typename Turn>
inline bool apply(Turn const& turn) const
{
BOOST_ASSERT(boost::size(m_linestring) > 1);
return m_is_closed
&& turn.method == overlay::method_none
&& check_segment_indices(turn, boost::size(m_linestring) - 2)
&& turn.operations[0].fraction.is_zero();
}
private:
Linestring const& m_linestring;
bool const m_is_closed;
};
template <typename MultiLinestring>
class is_acceptable_turn<MultiLinestring, multi_linestring_tag>
{
private:
typedef typename boost::range_value<MultiLinestring>::type linestring_type;
typedef is_acceptable_turn<linestring_type> base_type;
template <typename Point, typename Linestring>
static inline bool is_boundary_point_of(Point const& point,
Linestring const& linestring)
{
BOOST_ASSERT(boost::size(linestring) > 1);
return
! geometry::equals(range::front(linestring),
range::back(linestring))
&&
(geometry::equals(point, range::front(linestring))
|| geometry::equals(point, range::back(linestring)));
}
template <typename Turn, typename Linestring>
static inline bool is_closing_point_of(Turn const& turn,
Linestring const& linestring)
{
BOOST_ASSERT(boost::size(linestring) > 1);
return
turn.method == overlay::method_none
&&
check_segment_indices(turn, boost::size(linestring) - 2)
&&
geometry::equals(range::front(linestring), range::back(linestring))
&&
turn.operations[0].fraction.is_zero();
;
}
template <typename Linestring1, typename Linestring2>
static inline bool have_same_boundary_points(Linestring1 const& ls1,
Linestring2 const& ls2)
{
return
geometry::equals(range::front(ls1), range::front(ls2))
?
geometry::equals(range::back(ls1), range::back(ls2))
:
(geometry::equals(range::front(ls1), range::back(ls2))
&&
geometry::equals(range::back(ls1), range::front(ls2)))
;
}
public:
is_acceptable_turn(MultiLinestring const& multilinestring)
: m_multilinestring(multilinestring)
{}
template <typename Turn>
inline bool apply(Turn const& turn) const
{
linestring_type const& ls1 =
range::at(m_multilinestring, turn.operations[0].seg_id.multi_index);
linestring_type const& ls2 =
range::at(m_multilinestring, turn.operations[1].seg_id.multi_index);
if (turn.operations[0].seg_id.multi_index
== turn.operations[1].seg_id.multi_index)
{
return is_closing_point_of(turn, ls1);
}
return
is_boundary_point_of(turn.point, ls1)
&& is_boundary_point_of(turn.point, ls2)
&&
( boost::size(ls1) != 2
|| boost::size(ls2) != 2
|| ! have_same_boundary_points(ls1, ls2) );
}
private:
MultiLinestring const& m_multilinestring;
};
template <typename Linear>
inline bool has_self_intersections(Linear const& linear)
{
typedef typename point_type<Linear>::type point_type;
// compute self turns
typedef detail::overlay::turn_info
<
point_type,
geometry::segment_ratio
<
typename geometry::coordinate_type<point_type>::type
>
> turn_info;
std::deque<turn_info> turns;
typedef detail::overlay::get_turn_info
<
detail::disjoint::assign_disjoint_policy
> turn_policy;
is_acceptable_turn<Linear> predicate(linear);
detail::overlay::predicate_based_interrupt_policy
<
is_acceptable_turn<Linear>
> interrupt_policy(predicate);
detail::self_get_turn_points::get_turns
<
turn_policy
>::apply(linear,
detail::no_rescale_policy(),
turns,
interrupt_policy);
detail::is_valid::debug_print_turns(turns.begin(), turns.end());
debug_print_boundary_points(linear);
return interrupt_policy.has_intersections;
}
template <typename Linestring, bool CheckSelfIntersections = true>
struct is_simple_linestring
{
static inline bool apply(Linestring const& linestring)
{
simplicity_failure_policy policy;
return ! detail::is_valid::has_duplicates
<
Linestring, closed
>::apply(linestring, policy)
&& ! detail::is_valid::has_spikes
<
Linestring, closed
>::apply(linestring, policy)
&& ! (CheckSelfIntersections && has_self_intersections(linestring));
}
};
template <typename MultiLinestring>
struct is_simple_multilinestring
{
static inline bool apply(MultiLinestring const& multilinestring)
{
// check each of the linestrings for simplicity
// but do not compute self-intersections yet; these will be
// computed for the entire multilinestring
if ( ! detail::check_iterator_range
<
is_simple_linestring
<
typename boost::range_value<MultiLinestring>::type,
false // do not compute self-intersections
>,
false // do not allow empty multilinestring
>::apply(boost::begin(multilinestring),
boost::end(multilinestring))
)
{
return false;
}
return ! has_self_intersections(multilinestring);
}
};
}} // namespace detail::is_simple
#endif // DOXYGEN_NO_DETAIL
#ifndef DOXYGEN_NO_DISPATCH
namespace dispatch
{
// A linestring 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
//
// Reference: OGC 06-103r4 (6.1.6.1)
template <typename Linestring>
struct is_simple<Linestring, linestring_tag>
: detail::is_simple::is_simple_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>
struct is_simple<MultiLinestring, multi_linestring_tag>
: detail::is_simple::is_simple_multilinestring<MultiLinestring>
{};
} // namespace dispatch
#endif // DOXYGEN_NO_DISPATCH
}} // namespace boost::geometry
#endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_SIMPLE_LINEAR_HPP
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