%PDF-
%PDF-
Mini Shell
Mini Shell
// Boost.Geometry (aka GGL, Generic Geometry Library)
// Copyright (c) 2017-2017 Barend Gehrels, Amsterdam, the Netherlands.
// 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_NEEDS_SELF_TURNS_HPP
#define BOOST_GEOMETRY_ALGORITHMS_DETAIL_OVERLAY_NEEDS_SELF_TURNS_HPP
#include <boost/range.hpp>
#include <boost/geometry/core/tags.hpp>
#include <boost/geometry/algorithms/num_interior_rings.hpp>
namespace boost { namespace geometry
{
#ifndef DOXYGEN_NO_DETAIL
namespace detail { namespace overlay
{
template
<
typename Geometry,
typename Tag = typename tag<Geometry>::type
>
struct needs_self_turns
{
};
template <typename Geometry>
struct needs_self_turns<Geometry, box_tag>
{
static inline bool apply(Geometry const&)
{
return false;
}
};
template <typename Geometry>
struct needs_self_turns<Geometry, ring_tag>
{
static inline bool apply(Geometry const&)
{
return false;
}
};
template <typename Geometry>
struct needs_self_turns<Geometry, polygon_tag>
{
static inline bool apply(Geometry const& polygon)
{
return geometry::num_interior_rings(polygon) > 0;
}
};
template <typename Geometry>
struct needs_self_turns<Geometry, multi_polygon_tag>
{
static inline bool apply(Geometry const& multi)
{
typedef typename boost::range_value<Geometry>::type polygon_type;
std::size_t const n = boost::size(multi);
return n > 1 || (n == 1
&& needs_self_turns<polygon_type>
::apply(*boost::begin(multi)));
}
};
}} // namespace detail::overlay
#endif // DOXYGEN_NO_DETAIL
}} // namespace boost::geometry
#endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_OVERLAY_NEEDS_SELF_TURNS_HPP
Zerion Mini Shell 1.0