// Boost.Geometry (aka GGL, Generic Geometry Library)
|
|
// Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
|
|
// This file was modified by Oracle on 2020.
|
// Modifications copyright (c) 2020 Oracle and/or its affiliates.
|
// 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_OVERLAY_GET_RING_HPP
|
#define BOOST_GEOMETRY_ALGORITHMS_DETAIL_OVERLAY_GET_RING_HPP
|
|
|
#include <boost/range/size.hpp>
|
#include <boost/range/value_type.hpp>
|
|
#include <boost/geometry/core/assert.hpp>
|
#include <boost/geometry/core/exterior_ring.hpp>
|
#include <boost/geometry/core/interior_rings.hpp>
|
#include <boost/geometry/core/ring_type.hpp>
|
#include <boost/geometry/core/tags.hpp>
|
#include <boost/geometry/algorithms/detail/ring_identifier.hpp>
|
#include <boost/geometry/algorithms/detail/overlay/segment_identifier.hpp>
|
#include <boost/geometry/algorithms/num_points.hpp>
|
#include <boost/geometry/geometries/concepts/check.hpp>
|
#include <boost/geometry/util/range.hpp>
|
|
|
namespace boost { namespace geometry
|
{
|
|
|
#ifndef DOXYGEN_NO_DETAIL
|
namespace detail { namespace overlay
|
{
|
|
|
template<typename Tag>
|
struct get_ring
|
{};
|
|
// A range of rings (multi-ring but that does not exist)
|
// gets the "void" tag and is dispatched here.
|
template<>
|
struct get_ring<void>
|
{
|
template<typename Range>
|
static inline typename boost::range_value<Range>::type const&
|
apply(ring_identifier const& id, Range const& container)
|
{
|
return range::at(container, id.multi_index);
|
}
|
};
|
|
|
template<>
|
struct get_ring<ring_tag>
|
{
|
template<typename Ring>
|
static inline Ring const& apply(ring_identifier const& , Ring const& ring)
|
{
|
return ring;
|
}
|
};
|
|
|
template<>
|
struct get_ring<box_tag>
|
{
|
template<typename Box>
|
static inline Box const& apply(ring_identifier const& ,
|
Box const& box)
|
{
|
return box;
|
}
|
};
|
|
|
template<>
|
struct get_ring<polygon_tag>
|
{
|
template<typename Polygon>
|
static inline typename ring_return_type<Polygon const>::type const apply(
|
ring_identifier const& id,
|
Polygon const& polygon)
|
{
|
BOOST_GEOMETRY_ASSERT
|
(
|
id.ring_index >= -1
|
&& id.ring_index < int(boost::size(interior_rings(polygon)))
|
);
|
return id.ring_index < 0
|
? exterior_ring(polygon)
|
: range::at(interior_rings(polygon), id.ring_index);
|
}
|
};
|
|
|
template<>
|
struct get_ring<multi_polygon_tag>
|
{
|
template<typename MultiPolygon>
|
static inline typename ring_type<MultiPolygon>::type const& apply(
|
ring_identifier const& id,
|
MultiPolygon const& multi_polygon)
|
{
|
BOOST_GEOMETRY_ASSERT
|
(
|
id.multi_index >= 0
|
&& id.multi_index < int(boost::size(multi_polygon))
|
);
|
return get_ring<polygon_tag>::apply(id,
|
range::at(multi_polygon, id.multi_index));
|
}
|
};
|
|
|
template <typename Geometry>
|
inline std::size_t segment_count_on_ring(Geometry const& geometry,
|
segment_identifier const& seg_id)
|
{
|
typedef typename geometry::tag<Geometry>::type tag;
|
ring_identifier const rid(0, seg_id.multi_index, seg_id.ring_index);
|
// A closed polygon, a triangle of 4 points, including starting point,
|
// contains 3 segments. So handle as if closed and subtract one.
|
return geometry::num_points(detail::overlay::get_ring<tag>::apply(rid, geometry), true) - 1;
|
}
|
|
}} // namespace detail::overlay
|
#endif // DOXYGEN_NO_DETAIL
|
|
|
}} // namespace boost::geometry
|
|
|
#endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_OVERLAY_GET_RING_HPP
|
