diff options
Diffstat (limited to 'boost/geometry/strategies/geographic/buffer_point_circle.hpp')
| -rw-r--r-- | boost/geometry/strategies/geographic/buffer_point_circle.hpp | 96 |
1 files changed, 47 insertions, 49 deletions
diff --git a/boost/geometry/strategies/geographic/buffer_point_circle.hpp b/boost/geometry/strategies/geographic/buffer_point_circle.hpp index 8d6643d73d..8aa7fce24e 100644 --- a/boost/geometry/strategies/geographic/buffer_point_circle.hpp +++ b/boost/geometry/strategies/geographic/buffer_point_circle.hpp @@ -1,9 +1,9 @@ // Boost.Geometry -// Copyright (c) 2018-2019 Barend Gehrels, Amsterdam, the Netherlands. +// Copyright (c) 2018-2022 Barend Gehrels, Amsterdam, the Netherlands. -// This file was modified by Oracle on 2020. -// Modifications copyright (c) 2020 Oracle and/or its affiliates. +// This file was modified by Oracle on 2020-2021. +// Modifications copyright (c) 2020-2021 Oracle and/or its affiliates. // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle // Use, modification and distribution is subject to the Boost Software License, @@ -17,10 +17,14 @@ #include <boost/range/value_type.hpp> -#include <boost/geometry/util/math.hpp> -#include <boost/geometry/util/select_calculation_type.hpp> +#include <boost/geometry/core/radian_access.hpp> +#include <boost/geometry/srs/spheroid.hpp> #include <boost/geometry/strategies/buffer.hpp> +#include <boost/geometry/strategies/geographic/buffer_helper.hpp> +#include <boost/geometry/strategies/geographic/parameters.hpp> +#include <boost/geometry/util/math.hpp> +#include <boost/geometry/util/select_calculation_type.hpp> namespace boost { namespace geometry @@ -55,81 +59,75 @@ template class geographic_point_circle { public : + + //! \brief Constructs the strategy with a spheroid + //! \param spheroid The spheroid to be used + //! \param count Number of points (minimum 3) for the created circle + explicit inline geographic_point_circle(Spheroid const& spheroid, + std::size_t count = default_points_per_circle) + : m_spheroid(spheroid) + , m_count(get_point_count_for_circle(count)) + {} + //! \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) + //! \param count Number of points (minimum 3) for the created circle + explicit inline geographic_point_circle(std::size_t count = default_points_per_circle) + : m_count(get_point_count_for_circle(count)) {} #ifndef DOXYGEN_SHOULD_SKIP_THIS - //! Fills output_range with a circle around point using distance_strategy + //! Fills range_out with a circle around point using distance_strategy template < typename Point, - typename OutputRange, - typename DistanceStrategy + typename DistanceStrategy, + typename RangeOut > inline void apply(Point const& point, - DistanceStrategy const& distance_strategy, - OutputRange& output_range) const + DistanceStrategy const& distance_strategy, + RangeOut& range_out) const { - typedef typename boost::range_value<OutputRange>::type output_point_type; - - typedef typename select_calculation_type + using calc_t = typename select_calculation_type < - Point, output_point_type, + Point, + typename boost::range_value<RangeOut>::type, CalculationType - //double - >::type calculation_type; + >::type; - calculation_type const buffer_distance = distance_strategy.apply(point, point, - strategy::buffer::buffer_side_left); + using helper = geographic_buffer_helper<FormulaPolicy, calc_t>; - typedef typename FormulaPolicy::template direct - < - calculation_type, true, false, false, false - > direct_t; + calc_t const lon_rad = get_as_radian<0>(point); + calc_t const lat_rad = get_as_radian<1>(point); + + calc_t const buffer_distance = distance_strategy.apply(point, + point, strategy::buffer::buffer_side_left); - calculation_type const two_pi = geometry::math::two_pi<calculation_type>(); - calculation_type const pi = geometry::math::pi<calculation_type>(); + calc_t const two_pi = geometry::math::two_pi<calc_t>(); + calc_t const pi = geometry::math::pi<calc_t>(); - 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; + calc_t const diff = two_pi / calc_t(m_count); + calc_t angle = -pi; for (std::size_t i = 0; i < m_count; i++, angle += diff) { - if (angle > pi) - { - angle -= two_pi; - } - - 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); + // If angle is zero, shift angle a tiny bit to avoid spikes. + calc_t const eps = angle == 0 ? 1.0e-10 : 0.0; + helper::append_point(lon_rad, lat_rad, buffer_distance, angle + eps, m_spheroid, range_out); } { // Close the range - const output_point_type p = output_range.front(); - output_range.push_back(p); + auto const p = range_out.front(); + range_out.push_back(p); } } #endif // DOXYGEN_SHOULD_SKIP_THIS private : - std::size_t m_count; Spheroid m_spheroid; + std::size_t m_count; }; - }} // namespace strategy::buffer }} // namespace boost::geometry |