/usr/include/boost/geometry/algorithms/area.hpp is in libboost1.55-dev 1.55.0+dfsg-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 | // 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.
// 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_ALGORITHMS_AREA_HPP
#define BOOST_GEOMETRY_ALGORITHMS_AREA_HPP
#include <boost/concept_check.hpp>
#include <boost/mpl/if.hpp>
#include <boost/range/functions.hpp>
#include <boost/range/metafunctions.hpp>
#include <boost/variant/static_visitor.hpp>
#include <boost/variant/apply_visitor.hpp>
#include <boost/variant/variant_fwd.hpp>
#include <boost/geometry/core/closure.hpp>
#include <boost/geometry/core/exterior_ring.hpp>
#include <boost/geometry/core/interior_rings.hpp>
#include <boost/geometry/core/point_order.hpp>
#include <boost/geometry/core/ring_type.hpp>
#include <boost/geometry/geometries/concepts/check.hpp>
#include <boost/geometry/algorithms/detail/calculate_null.hpp>
#include <boost/geometry/algorithms/detail/calculate_sum.hpp>
// #include <boost/geometry/algorithms/detail/throw_on_empty_input.hpp>
#include <boost/geometry/strategies/area.hpp>
#include <boost/geometry/strategies/default_area_result.hpp>
#include <boost/geometry/strategies/concepts/area_concept.hpp>
#include <boost/geometry/util/math.hpp>
#include <boost/geometry/util/order_as_direction.hpp>
#include <boost/geometry/views/closeable_view.hpp>
#include <boost/geometry/views/reversible_view.hpp>
namespace boost { namespace geometry
{
#ifndef DOXYGEN_NO_DETAIL
namespace detail { namespace area
{
struct box_area
{
template <typename Box, typename Strategy>
static inline typename coordinate_type<Box>::type
apply(Box const& box, Strategy const&)
{
// Currently only works for 2D Cartesian boxes
assert_dimension<Box, 2>();
return (get<max_corner, 0>(box) - get<min_corner, 0>(box))
* (get<max_corner, 1>(box) - get<min_corner, 1>(box));
}
};
template
<
iterate_direction Direction,
closure_selector Closure
>
struct ring_area
{
template <typename Ring, typename Strategy>
static inline typename Strategy::return_type
apply(Ring const& ring, Strategy const& strategy)
{
BOOST_CONCEPT_ASSERT( (geometry::concept::AreaStrategy<Strategy>) );
assert_dimension<Ring, 2>();
// Ignore warning (because using static method sometimes) on strategy
boost::ignore_unused_variable_warning(strategy);
// An open ring has at least three points,
// A closed ring has at least four points,
// if not, there is no (zero) area
if (int(boost::size(ring))
< core_detail::closure::minimum_ring_size<Closure>::value)
{
return typename Strategy::return_type();
}
typedef typename reversible_view<Ring const, Direction>::type rview_type;
typedef typename closeable_view
<
rview_type const, Closure
>::type view_type;
typedef typename boost::range_iterator<view_type const>::type iterator_type;
rview_type rview(ring);
view_type view(rview);
typename Strategy::state_type state;
iterator_type it = boost::begin(view);
iterator_type end = boost::end(view);
for (iterator_type previous = it++;
it != end;
++previous, ++it)
{
strategy.apply(*previous, *it, state);
}
return strategy.result(state);
}
};
}} // namespace detail::area
#endif // DOXYGEN_NO_DETAIL
#ifndef DOXYGEN_NO_DISPATCH
namespace dispatch
{
template
<
typename Geometry,
typename Tag = typename tag<Geometry>::type
>
struct area : detail::calculate_null
{
template <typename Strategy>
static inline typename Strategy::return_type apply(Geometry const& geometry, Strategy const& strategy)
{
return calculate_null::apply<typename Strategy::return_type>(geometry, strategy);
}
};
template <typename Geometry>
struct area<Geometry, box_tag> : detail::area::box_area
{};
template <typename Ring>
struct area<Ring, ring_tag>
: detail::area::ring_area
<
order_as_direction<geometry::point_order<Ring>::value>::value,
geometry::closure<Ring>::value
>
{};
template <typename Polygon>
struct area<Polygon, polygon_tag> : detail::calculate_polygon_sum
{
template <typename Strategy>
static inline typename Strategy::return_type apply(Polygon const& polygon, Strategy const& strategy)
{
return calculate_polygon_sum::apply<
typename Strategy::return_type,
detail::area::ring_area
<
order_as_direction<geometry::point_order<Polygon>::value>::value,
geometry::closure<Polygon>::value
>
>(polygon, strategy);
}
};
template <typename Geometry>
struct devarianted_area
{
template <typename Strategy>
static inline typename Strategy::return_type apply(Geometry const& geometry,
Strategy const& strategy)
{
return area<Geometry>::apply(geometry, strategy);
}
};
template <BOOST_VARIANT_ENUM_PARAMS(typename T)>
struct devarianted_area<boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> >
{
template <typename Strategy>
struct visitor: boost::static_visitor<typename Strategy::return_type>
{
Strategy const& m_strategy;
visitor(Strategy const& strategy): m_strategy(strategy) {}
template <typename Geometry>
typename Strategy::return_type operator()(Geometry const& geometry) const
{
return devarianted_area<Geometry>::apply(geometry, m_strategy);
}
};
template <typename Strategy>
static inline typename Strategy::return_type
apply(boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> const& geometry,
Strategy const& strategy)
{
return boost::apply_visitor(visitor<Strategy>(strategy), geometry);
}
};
} // namespace dispatch
#endif // DOXYGEN_NO_DISPATCH
/*!
\brief \brief_calc{area}
\ingroup area
\details \details_calc{area}. \details_default_strategy
The area algorithm calculates the surface area of all geometries having a surface, namely
box, polygon, ring, multipolygon. The units are the square of the units used for the points
defining the surface. If subject geometry is defined in meters, then area is calculated
in square meters.
The area calculation can be done in all three common coordinate systems, Cartesian, Spherical
and Geographic as well.
\tparam Geometry \tparam_geometry
\param geometry \param_geometry
\return \return_calc{area}
\qbk{[include reference/algorithms/area.qbk]}
\qbk{[heading Examples]}
\qbk{[area] [area_output]}
*/
template <typename Geometry>
inline typename default_area_result<Geometry>::type area(Geometry const& geometry)
{
concept::check<Geometry const>();
typedef typename point_type<Geometry>::type point_type;
typedef typename strategy::area::services::default_strategy
<
typename cs_tag<point_type>::type,
point_type
>::type strategy_type;
// detail::throw_on_empty_input(geometry);
return dispatch::devarianted_area<Geometry>::apply(geometry, strategy_type());
}
/*!
\brief \brief_calc{area} \brief_strategy
\ingroup area
\details \details_calc{area} \brief_strategy. \details_strategy_reasons
\tparam Geometry \tparam_geometry
\tparam Strategy \tparam_strategy{Area}
\param geometry \param_geometry
\param strategy \param_strategy{area}
\return \return_calc{area}
\qbk{distinguish,with strategy}
\qbk{
[include reference/algorithms/area.qbk]
[heading Example]
[area_with_strategy]
[area_with_strategy_output]
[heading Available Strategies]
\* [link geometry.reference.strategies.strategy_area_surveyor Surveyor (cartesian)]
\* [link geometry.reference.strategies.strategy_area_huiller Huiller (spherical)]
}
*/
template <typename Geometry, typename Strategy>
inline typename Strategy::return_type area(
Geometry const& geometry, Strategy const& strategy)
{
concept::check<Geometry const>();
// detail::throw_on_empty_input(geometry);
return dispatch::devarianted_area<Geometry>::apply(geometry, strategy);
}
}} // namespace boost::geometry
#endif // BOOST_GEOMETRY_ALGORITHMS_AREA_HPP
|