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+// Boost.Geometry (aka GGL, Generic Geometry Library)
+// Copyright (c) 2012-2014 Barend Gehrels, 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_STRATEGIES_CARTESIAN_BUFFER_POINT_CIRCLE_HPP
+#define BOOST_GEOMETRY_STRATEGIES_CARTESIAN_BUFFER_POINT_CIRCLE_HPP
+
+#include <cstddef>
+
+#include <boost/range.hpp>
+
+#include <boost/geometry/util/math.hpp>
+
+#include <boost/geometry/strategies/buffer.hpp>
+
+
+namespace boost { namespace geometry
+{
+
+namespace strategy { namespace buffer
+{
+
+/*!
+\brief Create a circular buffer around a point
+\ingroup strategies
+\details This strategy can be used as PointStrategy for the buffer algorithm.
+ It creates a circular buffer around a point. It can be applied
+ for points and multi_points, but also for a linestring (if it is degenerate,
+ so consisting of only one point) and for polygons (if it is degenerate).
+ This strategy is only applicable for Cartesian coordinate systems.
+
+\qbk{
+[heading Example]
+[buffer_point_circle]
+[heading Output]
+[$img/strategies/buffer_point_circle.png]
+[heading See also]
+\* [link geometry.reference.algorithms.buffer.buffer_7_with_strategies buffer (with strategies)]
+\* [link geometry.reference.strategies.strategy_buffer_point_square point_square]
+}
+ */
+class point_circle
+{
+public :
+ //! \brief Constructs the strategy
+ //! \param count number of points for the created circle
+ explicit point_circle(std::size_t count = 90)
+ : m_count(count)
+ {}
+
+#ifndef DOXYGEN_SHOULD_SKIP_THIS
+ //! Fills output_range with a circle around point using distance_strategy
+ template
+ <
+ typename Point,
+ typename OutputRange,
+ typename DistanceStrategy
+ >
+ inline void apply(Point const& point,
+ DistanceStrategy const& distance_strategy,
+ OutputRange& output_range) const
+ {
+ typedef typename boost::range_value<OutputRange>::type output_point_type;
+
+ typedef typename geometry::select_most_precise
+ <
+ typename geometry::select_most_precise
+ <
+ typename geometry::coordinate_type<Point>::type,
+ typename geometry::coordinate_type<output_point_type>::type
+ >::type,
+ double
+ >::type promoted_type;
+
+ promoted_type const buffer_distance = distance_strategy.apply(point, point,
+ strategy::buffer::buffer_side_left);
+
+ promoted_type const two = 2.0;
+ promoted_type const two_pi = two * geometry::math::pi<promoted_type>();
+
+ promoted_type const diff = two_pi / promoted_type(m_count);
+ promoted_type a = 0;
+
+ for (std::size_t i = 0; i < m_count; i++, a -= diff)
+ {
+ output_point_type p;
+ set<0>(p, get<0>(point) + buffer_distance * cos(a));
+ set<1>(p, get<1>(point) + buffer_distance * sin(a));
+ output_range.push_back(p);
+ }
+
+ // Close it:
+ output_range.push_back(output_range.front());
+ }
+#endif // DOXYGEN_SHOULD_SKIP_THIS
+
+private :
+ std::size_t m_count;
+};
+
+
+}} // namespace strategy::buffer
+
+}} // namespace boost::geometry
+
+#endif // BOOST_GEOMETRY_STRATEGIES_CARTESIAN_BUFFER_POINT_CIRCLE_HPP