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+// Boost.Geometry
+
+// Copyright (c) 2018-2019 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_GEOGRAPHIC_BUFFER_POINT_CIRCLE_HPP
+#define BOOST_GEOMETRY_STRATEGIES_GEOGRAPHIC_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, on the Earth
+\ingroup strategies
+\details This strategy can be used as PointStrategy for the buffer algorithm.
+ It creates a circular buffer around a point, on the Earth. It can be applied
+ for points and multi_points.
+
+\qbk{
+[heading Example]
+[buffer_geographic_point_circle]
+[buffer_geographic_point_circle_output]
+[heading See also]
+\* [link geometry.reference.algorithms.buffer.buffer_7_with_strategies buffer (with strategies)]
+\* [link geometry.reference.strategies.strategy_buffer_point_circle point_circle]
+\* [link geometry.reference.strategies.strategy_buffer_point_square point_square]
+}
+ */
+template
+<
+ typename FormulaPolicy = strategy::andoyer,
+ typename Spheroid = srs::spheroid<double>,
+ typename CalculationType = void
+>
+class geographic_point_circle
+{
+public :
+ //! \brief Constructs the strategy
+ //! \param count number of points for the created circle (if count
+ //! is smaller than 3, count is internally set to 3)
+ explicit geographic_point_circle(std::size_t count = 90)
+ : m_count((count < 3u) ? 3u : 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 select_most_precise
+ <
+ typename geometry::coordinate_type<Point>::type,
+ typename geometry::coordinate_type<output_point_type>::type,
+ CalculationType
+ //double
+ >::type calculation_type;
+
+ calculation_type const buffer_distance = distance_strategy.apply(point, point,
+ strategy::buffer::buffer_side_left);
+
+ typedef typename FormulaPolicy::template direct
+ <
+ calculation_type, true, false, false, false
+ > direct_t;
+
+ calculation_type const two_pi = geometry::math::two_pi<calculation_type>();
+
+ calculation_type const diff = two_pi / calculation_type(m_count);
+ // TODO: after calculation of some angles is corrected,
+ // we can start at 0.0
+ calculation_type angle = 0.001;
+
+ for (std::size_t i = 0; i < m_count; i++, angle += diff)
+ {
+ typename direct_t::result_type
+ dir_r = direct_t::apply(get_as_radian<0>(point), get_as_radian<1>(point),
+ buffer_distance, angle,
+ m_spheroid);
+ output_point_type p;
+ set_from_radian<0>(p, dir_r.lon2);
+ set_from_radian<1>(p, dir_r.lat2);
+ output_range.push_back(p);
+ }
+
+ {
+ // Close the range
+ const output_point_type p = output_range.front();
+ output_range.push_back(p);
+ }
+ }
+#endif // DOXYGEN_SHOULD_SKIP_THIS
+
+private :
+ std::size_t m_count;
+ Spheroid m_spheroid;
+};
+
+
+}} // namespace strategy::buffer
+
+}} // namespace boost::geometry
+
+#endif // BOOST_GEOMETRY_STRATEGIES_GEOGRAPHIC_BUFFER_POINT_CIRCLE_HPP