// Boost.Geometry (aka GGL, Generic Geometry Library) // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands. // Copyright (c) 2008-2012 Bruno Lalande, Paris, France. // Copyright (c) 2009-2012 Mateusz Loskot, London, UK. // This file was modified by Oracle on 2020-2023. // Modifications copyright (c) 2020-2023 Oracle and/or its affiliates. // Contributed and/or modified by Vissarion Fysikopoulos, on behalf of Oracle // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library // (geolib/GGL), copyright (c) 1995-2010 Geodan, 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_VIEWS_REVERSIBLE_VIEW_HPP #define BOOST_GEOMETRY_VIEWS_REVERSIBLE_VIEW_HPP #include <boost/version.hpp> #include <boost/range/adaptor/reversed.hpp> #include <boost/geometry/core/closure.hpp> #include <boost/geometry/core/point_order.hpp> #include <boost/geometry/core/ring_type.hpp> #include <boost/geometry/core/tag.hpp> #include <boost/geometry/core/tags.hpp> #include <boost/geometry/util/order_as_direction.hpp> #include <boost/geometry/views/identity_view.hpp> namespace boost { namespace geometry { #ifndef DOXYGEN_NO_DETAIL namespace detail { template < typename Range, order_selector Order = geometry::point_order<Range>::value > struct clockwise_view : identity_view<Range> { explicit inline clockwise_view(Range& r) : identity_view<Range>(r) {} }; template <typename Range> struct clockwise_view<Range, counterclockwise> : boost::reversed_range<Range> { explicit inline clockwise_view(Range& r) : boost::reversed_range<Range>(r) {} }; } // namespace detail #endif // DOXYGEN_NO_DETAIL /*! \brief View on a range, reversing direction if necessary \tparam Range original range \tparam Direction direction of iteration \ingroup views */ template <typename Range, iterate_direction Direction> struct reversible_view {}; #ifndef DOXYGEN_NO_SPECIALIZATIONS template <typename Range> struct reversible_view<Range, iterate_forward> { using type = identity_view<Range>; }; template <typename Range> struct reversible_view<Range, iterate_reverse> { using type = boost::reversed_range<Range>; }; #endif // DOXYGEN_NO_SPECIALIZATIONS #ifndef DOXYGEN_NO_TRAITS_SPECIALIZATIONS namespace traits { template <typename Range, order_selector Order> struct tag<geometry::detail::clockwise_view<Range, Order> > : geometry::tag<Range> {}; template <typename Range, order_selector Order> struct point_order<geometry::detail::clockwise_view<Range, Order> > { static const order_selector value = clockwise; }; template <typename Range, order_selector Order> struct closure<geometry::detail::clockwise_view<Range, Order> > : geometry::closure<Range> {}; } // namespace traits #endif // DOXYGEN_NO_TRAITS_SPECIALIZATIONS }} // namespace boost::geometry #endif // BOOST_GEOMETRY_VIEWS_REVERSIBLE_VIEW_HPP