adapted/boost_polygon/hole_iterator.hpp

0001 // Boost.Geometry (aka GGL, Generic Geometry Library)
0002
0003 // Copyright (c) 2010-2012 Barend Gehrels, Amsterdam, the Netherlands.
0004
0005 // Use, modification and distribution is subject to the Boost Software License,
0006 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
0007 // http://www.boost.org/LICENSE_1_0.txt)
0008
0009 #ifndef BOOST_GEOMETRY_GEOMETRIES_ADAPTED_BOOST_POLYGON_HOLE_ITERATOR_HPP
0010 #define BOOST_GEOMETRY_GEOMETRIES_ADAPTED_BOOST_POLYGON_HOLE_ITERATOR_HPP
0011
0012 // Adapts Geometries from Boost.Polygon for usage in Boost.Geometry
0013 // boost::polygon::polygon_with_holes_data -> boost::geometry::polygon
0014 //   hole_iterator  -> returning ring_proxy's instead of normal polygon_data
0015
0016 #include <boost/polygon/polygon.hpp>
0017
0018 #include <boost/iterator/iterator_facade.hpp>
0019
0020
0021 namespace boost { namespace geometry
0022 {
0023
0024 namespace adapt { namespace bp
0025 {
0026
0027
0028 template <typename Polygon, typename RingProxy>
0029 class hole_iterator
0030     : public ::boost::iterator_facade
0031         <
0032             hole_iterator<Polygon, RingProxy>,
0033             RingProxy, // value type
0034             boost::forward_traversal_tag,
0035             RingProxy // reference type
0036         >
0037 {
0038 public :
0039     typedef typename boost::polygon::polygon_with_holes_traits
0040         <
0041             Polygon
0042         >::iterator_holes_type ith_type;
0043
0044     explicit inline hole_iterator(Polygon& polygon, ith_type const it)
0045         : m_polygon(polygon)
0046         , m_base(it)
0047     {
0048     }
0049
0050     typedef std::ptrdiff_t difference_type;
0051
0052 private:
0053     friend class boost::iterator_core_access;
0054
0055     inline RingProxy dereference() const
0056     {
0057         return RingProxy(m_polygon, this->m_base);
0058     }
0059
0060     inline void increment() { ++m_base; }
0061     inline void decrement() { --m_base; }
0062     inline void advance(difference_type n)
0063     {
0064         for (int i = 0; i < n; i++)
0065         {
0066             ++m_base;
0067         }
0068     }
0069
0070     inline bool equal(hole_iterator<Polygon, RingProxy> const& other) const
0071     {
0072         return this->m_base == other.m_base;
0073     }
0074
0075     Polygon& m_polygon;
0076     ith_type m_base;
0077 };
0078
0079
0080 }}}}
0081
0082 #endif // BOOST_GEOMETRY_GEOMETRIES_ADAPTED_BOOST_POLYGON_HOLE_ITERATOR_HPP
0083