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Diffstat (limited to 'boost/geometry/strategies/geographic/buffer_point_circle.hpp')
-rw-r--r-- | boost/geometry/strategies/geographic/buffer_point_circle.hpp | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/boost/geometry/strategies/geographic/buffer_point_circle.hpp b/boost/geometry/strategies/geographic/buffer_point_circle.hpp new file mode 100644 index 0000000000..7e7c8fe81d --- /dev/null +++ b/boost/geometry/strategies/geographic/buffer_point_circle.hpp @@ -0,0 +1,127 @@ +// 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 |