Imported Upstream version 1.49.0upstream/1.49.0

1 files changed, 295 insertions, 0 deletions

diff --git a/boost/geometry/algorithms/area.hpp b/boost/geometry/algorithms/area.hpp
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+// 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/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
+{
+
+template<typename Box, typename Strategy>
+struct box_area
+{
+    typedef typename coordinate_type<Box>::type return_type;
+
+    static inline return_type apply(Box const& box, Strategy const&)
+    {
+        // Currently only works for 2D Cartesian boxes
+        assert_dimension<Box, 2>();
+
+        return_type const dx = get<max_corner, 0>(box)
+                - get<min_corner, 0>(box);
+        return_type const dy = get<max_corner, 1>(box)
+                - get<min_corner, 1>(box);
+
+        return dx * dy;
+    }
+};
+
+
+template
+<
+    typename Ring,
+    iterate_direction Direction,
+    closure_selector Closure,
+    typename Strategy
+>
+struct ring_area
+{
+    BOOST_CONCEPT_ASSERT( (geometry::concept::AreaStrategy<Strategy>) );
+
+    typedef typename Strategy::return_type type;
+
+    static inline type apply(Ring const& ring, Strategy const& 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 (boost::size(ring)
+                < core_detail::closure::minimum_ring_size<Closure>::value)
+        {
+            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 Strategy = typename strategy::area::services::default_strategy
+                                 <
+                                     typename cs_tag
+                                     <
+                                         typename point_type<Geometry>::type
+                                     >::type,
+                                     typename point_type<Geometry>::type
+                                 >::type,
+    typename Tag = typename tag<Geometry>::type
+>
+struct area
+    : detail::calculate_null
+        <
+            typename Strategy::return_type,
+            Geometry,
+            Strategy
+        > {};
+
+
+template
+<
+    typename Geometry,
+    typename Strategy
+>
+struct area<Geometry, Strategy, box_tag>
+    : detail::area::box_area<Geometry, Strategy>
+{};
+
+
+template
+<
+    typename Ring,
+    typename Strategy
+>
+struct area<Ring, Strategy, ring_tag>
+    : detail::area::ring_area
+        <
+            Ring,
+            order_as_direction<geometry::point_order<Ring>::value>::value,
+            geometry::closure<Ring>::value,
+            Strategy
+        >
+{};
+
+
+template
+<
+    typename Polygon,
+    typename Strategy
+>
+struct area<Polygon, Strategy, polygon_tag>
+    : detail::calculate_polygon_sum
+        <
+            typename Strategy::return_type,
+            Polygon,
+            Strategy,
+            detail::area::ring_area
+                <
+                    typename ring_type<Polygon const>::type,
+                    order_as_direction<geometry::point_order<Polygon>::value>::value,
+                    geometry::closure<Polygon>::value,
+                    Strategy
+                >
+        >
+{};
+
+
+} // 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::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::area
+        <
+            Geometry,
+            Strategy
+        >::apply(geometry, strategy);
+}
+
+
+}} // namespace boost::geometry
+
+
+#endif // BOOST_GEOMETRY_ALGORITHMS_AREA_HPP