ceph/src/boost/libs/geometry/include/boost/geometry/algorithms/buffer.hpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2
   3 // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
   4 // Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
   5 // Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
   6
   7 // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
   8 // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
   9
  10 // Use, modification and distribution is subject to the Boost Software License,
  11 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  12 // http://www.boost.org/LICENSE_1_0.txt)
  13
  14 #ifndef BOOST_GEOMETRY_ALGORITHMS_BUFFER_HPP
  15 #define BOOST_GEOMETRY_ALGORITHMS_BUFFER_HPP
  16
  17 #include <cstddef>
  18
  19 #include <boost/numeric/conversion/cast.hpp>
  20
  21 #include <boost/range.hpp>
  22
  23 #include <boost/variant/apply_visitor.hpp>
  24 #include <boost/variant/static_visitor.hpp>
  25 #include <boost/variant/variant_fwd.hpp>
  26
  27 #include <boost/geometry/algorithms/clear.hpp>
  28 #include <boost/geometry/algorithms/envelope.hpp>
  29 #include <boost/geometry/algorithms/is_empty.hpp>
  30 #include <boost/geometry/algorithms/not_implemented.hpp>
  31 #include <boost/geometry/arithmetic/arithmetic.hpp>
  32 #include <boost/geometry/geometries/concepts/check.hpp>
  33 #include <boost/geometry/geometries/box.hpp>
  34 #include <boost/geometry/util/math.hpp>
  35
  36 #include <boost/geometry/algorithms/detail/buffer/buffer_inserter.hpp>
  37
  38 namespace boost { namespace geometry
  39 {
  40
  41
  42 #ifndef DOXYGEN_NO_DETAIL
  43 namespace detail { namespace buffer
  44 {
  45
  46 template <typename BoxIn, typename BoxOut, typename T, std::size_t C, std::size_t D, std::size_t N>
  47 struct box_loop
  48 {
  49     typedef typename coordinate_type<BoxOut>::type coordinate_type;
  50
  51     static inline void apply(BoxIn const& box_in, T const& distance, BoxOut& box_out)
  52     {
  53         coordinate_type d = distance;
  54         set<C, D>(box_out, get<C, D>(box_in) + d);
  55         box_loop<BoxIn, BoxOut, T, C, D + 1, N>::apply(box_in, distance, box_out);
  56     }
  57 };
  58
  59 template <typename BoxIn, typename BoxOut, typename T, std::size_t C, std::size_t N>
  60 struct box_loop<BoxIn, BoxOut, T, C, N, N>
  61 {
  62     static inline void apply(BoxIn const&, T const&, BoxOut&) {}
  63 };
  64
  65 // Extends a box with the same amount in all directions
  66 template<typename BoxIn, typename BoxOut, typename T>
  67 inline void buffer_box(BoxIn const& box_in, T const& distance, BoxOut& box_out)
  68 {
  69     assert_dimension_equal<BoxIn, BoxOut>();
  70
  71     static const std::size_t N = dimension<BoxIn>::value;
  72
  73     box_loop<BoxIn, BoxOut, T, min_corner, 0, N>::apply(box_in, -distance, box_out);
  74     box_loop<BoxIn, BoxOut, T, max_corner, 0, N>::apply(box_in, distance, box_out);
  75 }
  76
  77
  78
  79 }} // namespace detail::buffer
  80 #endif // DOXYGEN_NO_DETAIL
  81
  82 #ifndef DOXYGEN_NO_DISPATCH
  83 namespace dispatch
  84 {
  85
  86 template
  87 <
  88     typename Input,
  89     typename Output,
  90     typename TagIn = typename tag<Input>::type,
  91     typename TagOut = typename tag<Output>::type
  92 >
  93 struct buffer: not_implemented<TagIn, TagOut>
  94 {};
  95
  96
  97 template <typename BoxIn, typename BoxOut>
  98 struct buffer<BoxIn, BoxOut, box_tag, box_tag>
  99 {
 100     template <typename Distance>
 101     static inline void apply(BoxIn const& box_in, Distance const& distance,
 102                 Distance const& , BoxOut& box_out)
 103     {
 104         detail::buffer::buffer_box(box_in, distance, box_out);
 105     }
 106 };
 107
 108 } // namespace dispatch
 109 #endif // DOXYGEN_NO_DISPATCH
 110
 111
 112 namespace resolve_variant {
 113
 114 template <typename Geometry>
 115 struct buffer
 116 {
 117     template <typename Distance, typename GeometryOut>
 118     static inline void apply(Geometry const& geometry,
 119                              Distance const& distance,
 120                              Distance const& chord_length,
 121                              GeometryOut& out)
 122     {
 123         dispatch::buffer<Geometry, GeometryOut>::apply(geometry, distance, chord_length, out);
 124     }
 125 };
 126
 127 template <BOOST_VARIANT_ENUM_PARAMS(typename T)>
 128 struct buffer<boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> >
 129 {
 130     template <typename Distance, typename GeometryOut>
 131     struct visitor: boost::static_visitor<void>
 132     {
 133         Distance const& m_distance;
 134         Distance const& m_chord_length;
 135         GeometryOut& m_out;
 136
 137         visitor(Distance const& distance,
 138                 Distance const& chord_length,
 139                 GeometryOut& out)
 140         : m_distance(distance),
 141           m_chord_length(chord_length),
 142           m_out(out)
 143         {}
 144
 145         template <typename Geometry>
 146         void operator()(Geometry const& geometry) const
 147         {
 148             buffer<Geometry>::apply(geometry, m_distance, m_chord_length, m_out);
 149         }
 150     };
 151
 152     template <typename Distance, typename GeometryOut>
 153     static inline void apply(
 154         boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> const& geometry,
 155         Distance const& distance,
 156         Distance const& chord_length,
 157         GeometryOut& out
 158     )
 159     {
 160         boost::apply_visitor(visitor<Distance, GeometryOut>(distance, chord_length, out), geometry);
 161     }
 162 };
 163
 164 } // namespace resolve_variant
 165
 166
 167 /*!
 168 \brief \brief_calc{buffer}
 169 \ingroup buffer
 170 \details \details_calc{buffer, \det_buffer}.
 171 \tparam Input \tparam_geometry
 172 \tparam Output \tparam_geometry
 173 \tparam Distance \tparam_numeric
 174 \param geometry_in \param_geometry
 175 \param geometry_out \param_geometry
 176 \param distance The distance to be used for the buffer
 177 \param chord_length (optional) The length of the chord's in the generated arcs around points or bends
 178
 179 \qbk{[include reference/algorithms/buffer.qbk]}
 180  */
 181 template <typename Input, typename Output, typename Distance>
 182 inline void buffer(Input const& geometry_in, Output& geometry_out,
 183             Distance const& distance, Distance const& chord_length = -1)
 184 {
 185     concepts::check<Input const>();
 186     concepts::check<Output>();
 187
 188     resolve_variant::buffer<Input>::apply(geometry_in, distance, chord_length, geometry_out);
 189 }
 190
 191 /*!
 192 \brief \brief_calc{buffer}
 193 \ingroup buffer
 194 \details \details_calc{return_buffer, \det_buffer}. \details_return{buffer}.
 195 \tparam Input \tparam_geometry
 196 \tparam Output \tparam_geometry
 197 \tparam Distance \tparam_numeric
 198 \param geometry \param_geometry
 199 \param distance The distance to be used for the buffer
 200 \param chord_length (optional) The length of the chord's in the generated arcs
 201     around points or bends (RESERVED, NOT YET USED)
 202 \return \return_calc{buffer}
 203  */
 204 template <typename Output, typename Input, typename Distance>
 205 Output return_buffer(Input const& geometry, Distance const& distance, Distance const& chord_length = -1)
 206 {
 207     concepts::check<Input const>();
 208     concepts::check<Output>();
 209
 210     Output geometry_out;
 211
 212     resolve_variant::buffer<Input>::apply(geometry, distance, chord_length, geometry_out);
 213
 214     return geometry_out;
 215 }
 216
 217 /*!
 218 \brief \brief_calc{buffer}
 219 \ingroup buffer
 220 \details \details_calc{buffer, \det_buffer}.
 221 \tparam GeometryIn \tparam_geometry
 222 \tparam MultiPolygon \tparam_geometry{MultiPolygon}
 223 \tparam DistanceStrategy A strategy defining distance (or radius)
 224 \tparam SideStrategy A strategy defining creation along sides
 225 \tparam JoinStrategy A strategy defining creation around convex corners
 226 \tparam EndStrategy A strategy defining creation at linestring ends
 227 \tparam PointStrategy A strategy defining creation around points
 228 \param geometry_in \param_geometry
 229 \param geometry_out output multi polygon (or std:: collection of polygons),
 230     will contain a buffered version of the input geometry
 231 \param distance_strategy The distance strategy to be used
 232 \param side_strategy The side strategy to be used
 233 \param join_strategy The join strategy to be used
 234 \param end_strategy The end strategy to be used
 235 \param point_strategy The point strategy to be used
 236
 237 \qbk{distinguish,with strategies}
 238 \qbk{[include reference/algorithms/buffer_with_strategies.qbk]}
 239  */
 240 template
 241 <
 242     typename GeometryIn,
 243     typename MultiPolygon,
 244     typename DistanceStrategy,
 245     typename SideStrategy,
 246     typename JoinStrategy,
 247     typename EndStrategy,
 248     typename PointStrategy
 249 >
 250 inline void buffer(GeometryIn const& geometry_in,
 251                 MultiPolygon& geometry_out,
 252                 DistanceStrategy const& distance_strategy,
 253                 SideStrategy const& side_strategy,
 254                 JoinStrategy const& join_strategy,
 255                 EndStrategy const& end_strategy,
 256                 PointStrategy const& point_strategy)
 257 {
 258     typedef typename boost::range_value<MultiPolygon>::type polygon_type;
 259     concepts::check<GeometryIn const>();
 260     concepts::check<polygon_type>();
 261
 262     typedef typename point_type<GeometryIn>::type point_type;
 263     typedef typename rescale_policy_type<point_type>::type rescale_policy_type;
 264
 265     geometry_out.clear();
 266
 267     if (geometry::is_empty(geometry_in))
 268     {
 269         // Then output geometry is kept empty as well
 270         return;
 271     }
 272
 273     model::box<point_type> box;
 274     geometry::envelope(geometry_in, box);
 275     geometry::buffer(box, box, distance_strategy.max_distance(join_strategy, end_strategy));
 276
 277     rescale_policy_type rescale_policy
 278             = boost::geometry::get_rescale_policy<rescale_policy_type>(box);
 279
 280     detail::buffer::buffer_inserter<polygon_type>(geometry_in, range::back_inserter(geometry_out),
 281                 distance_strategy,
 282                 side_strategy,
 283                 join_strategy,
 284                 end_strategy,
 285                 point_strategy,
 286                 rescale_policy);
 287 }
 288
 289
 290 }} // namespace boost::geometry
 291
 292 #endif // BOOST_GEOMETRY_ALGORITHMS_BUFFER_HPP