Chris@16: // Boost.Geometry (aka GGL, Generic Geometry Library)
Chris@16: 
Chris@16: // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
Chris@16: // Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
Chris@16: // Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
Chris@16: 
Chris@16: // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
Chris@16: // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
Chris@16: 
Chris@16: // Use, modification and distribution is subject to the Boost Software License,
Chris@16: // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_GEOMETRY_ALGORITHMS_CLEAR_HPP
Chris@16: #define BOOST_GEOMETRY_ALGORITHMS_CLEAR_HPP
Chris@16: 
Chris@16: 
Chris@101: #include <boost/type_traits/remove_const.hpp>
Chris@101: 
Chris@101: #include <boost/variant/apply_visitor.hpp>
Chris@101: #include <boost/variant/static_visitor.hpp>
Chris@101: #include <boost/variant/variant_fwd.hpp>
Chris@101: 
Chris@16: #include <boost/geometry/algorithms/not_implemented.hpp>
Chris@16: #include <boost/geometry/core/access.hpp>
Chris@16: #include <boost/geometry/core/exterior_ring.hpp>
Chris@16: #include <boost/geometry/core/interior_rings.hpp>
Chris@16: #include <boost/geometry/core/mutable_range.hpp>
Chris@16: #include <boost/geometry/core/tag_cast.hpp>
Chris@101: #include <boost/geometry/core/tags.hpp>
Chris@16: #include <boost/geometry/geometries/concepts/check.hpp>
Chris@16: 
Chris@16: 
Chris@16: namespace boost { namespace geometry
Chris@16: {
Chris@16: 
Chris@16: #ifndef DOXYGEN_NO_DETAIL
Chris@16: namespace detail { namespace clear
Chris@16: {
Chris@16: 
Chris@16: template <typename Geometry>
Chris@16: struct collection_clear
Chris@16: {
Chris@16:     static inline void apply(Geometry& geometry)
Chris@16:     {
Chris@16:         traits::clear<Geometry>::apply(geometry);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: template <typename Polygon>
Chris@16: struct polygon_clear
Chris@16: {
Chris@16:     static inline void apply(Polygon& polygon)
Chris@16:     {
Chris@16:         traits::clear
Chris@16:             <
Chris@16:                 typename boost::remove_reference
Chris@16:                     <
Chris@16:                         typename traits::interior_mutable_type<Polygon>::type
Chris@16:                     >::type
Chris@16:             >::apply(interior_rings(polygon));
Chris@16:         traits::clear
Chris@16:             <
Chris@16:                 typename boost::remove_reference
Chris@16:                     <
Chris@16:                         typename traits::ring_mutable_type<Polygon>::type
Chris@16:                     >::type
Chris@16:             >::apply(exterior_ring(polygon));
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: template <typename Geometry>
Chris@16: struct no_action
Chris@16: {
Chris@16:     static inline void apply(Geometry& )
Chris@16:     {
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: 
Chris@16: }} // namespace detail::clear
Chris@16: #endif // DOXYGEN_NO_DETAIL
Chris@16: 
Chris@16: #ifndef DOXYGEN_NO_DISPATCH
Chris@16: namespace dispatch
Chris@16: {
Chris@16: 
Chris@16: template
Chris@16: <
Chris@16:     typename Geometry,
Chris@16:     typename Tag = typename tag_cast<typename tag<Geometry>::type, multi_tag>::type
Chris@16: >
Chris@16: struct clear: not_implemented<Tag>
Chris@16: {};
Chris@16: 
Chris@16: // Point/box/segment do not have clear. So specialize to do nothing.
Chris@16: template <typename Geometry>
Chris@16: struct clear<Geometry, point_tag>
Chris@16:     : detail::clear::no_action<Geometry>
Chris@16: {};
Chris@16: 
Chris@16: template <typename Geometry>
Chris@16: struct clear<Geometry, box_tag>
Chris@16:     : detail::clear::no_action<Geometry>
Chris@16: {};
Chris@16: 
Chris@16: template <typename Geometry>
Chris@16: struct clear<Geometry, segment_tag>
Chris@16:     : detail::clear::no_action<Geometry>
Chris@16: {};
Chris@16: 
Chris@16: template <typename Geometry>
Chris@16: struct clear<Geometry, linestring_tag>
Chris@16:     : detail::clear::collection_clear<Geometry>
Chris@16: {};
Chris@16: 
Chris@16: template <typename Geometry>
Chris@16: struct clear<Geometry, ring_tag>
Chris@16:     : detail::clear::collection_clear<Geometry>
Chris@16: {};
Chris@16: 
Chris@16: 
Chris@16: // Polygon can (indirectly) use std for clear
Chris@16: template <typename Polygon>
Chris@16: struct clear<Polygon, polygon_tag>
Chris@16:     : detail::clear::polygon_clear<Polygon>
Chris@16: {};
Chris@16: 
Chris@16: 
Chris@16: template <typename Geometry>
Chris@101: struct clear<Geometry, multi_tag>
Chris@101:     : detail::clear::collection_clear<Geometry>
Chris@101: {};
Chris@101: 
Chris@101: 
Chris@101: } // namespace dispatch
Chris@101: #endif // DOXYGEN_NO_DISPATCH
Chris@101: 
Chris@101: 
Chris@101: namespace resolve_variant {
Chris@101: 
Chris@101: template <typename Geometry>
Chris@101: struct clear
Chris@16: {
Chris@16:     static inline void apply(Geometry& geometry)
Chris@16:     {
Chris@101:         dispatch::clear<Geometry>::apply(geometry);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: template <BOOST_VARIANT_ENUM_PARAMS(typename T)>
Chris@101: struct clear<variant<BOOST_VARIANT_ENUM_PARAMS(T)> >
Chris@16: {
Chris@16:     struct visitor: static_visitor<void>
Chris@16:     {
Chris@16:         template <typename Geometry>
Chris@16:         inline void operator()(Geometry& geometry) const
Chris@16:         {
Chris@16:             clear<Geometry>::apply(geometry);
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16:     static inline void apply(variant<BOOST_VARIANT_ENUM_PARAMS(T)>& geometry)
Chris@16:     {
Chris@16:         apply_visitor(visitor(), geometry);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@101: } // namespace resolve_variant
Chris@16: 
Chris@16: 
Chris@16: /*!
Chris@16: \brief Clears a linestring, ring or polygon (exterior+interiors) or multi*
Chris@16: \details Generic function to clear a geometry. All points will be removed from the collection or collections
Chris@16:     making up the geometry. In most cases this is equivalent to the .clear() method of a std::vector<...>. In
Chris@16:     the case of a polygon, this clear functionality is automatically called for the exterior ring, and for the
Chris@16:     interior ring collection. In the case of a point, boxes and segments, nothing will happen.
Chris@16: \ingroup clear
Chris@16: \tparam Geometry \tparam_geometry
Chris@16: \param geometry \param_geometry which will be cleared
Chris@16: \note points and boxes cannot be cleared, instead they can be set to zero by "assign_zero"
Chris@16: 
Chris@16: \qbk{[include reference/algorithms/clear.qbk]}
Chris@16: */
Chris@16: template <typename Geometry>
Chris@16: inline void clear(Geometry& geometry)
Chris@16: {
Chris@16:     concept::check<Geometry>();
Chris@16: 
Chris@101:     resolve_variant::clear<Geometry>::apply(geometry);
Chris@16: }
Chris@16: 
Chris@16: 
Chris@16: }} // namespace boost::geometry
Chris@16: 
Chris@16: 
Chris@16: #endif // BOOST_GEOMETRY_ALGORITHMS_CLEAR_HPP