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Diffstat (limited to 'boost/geometry/strategies/geographic/buffer_side_straight.hpp')
-rw-r--r-- | boost/geometry/strategies/geographic/buffer_side_straight.hpp | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/boost/geometry/strategies/geographic/buffer_side_straight.hpp b/boost/geometry/strategies/geographic/buffer_side_straight.hpp new file mode 100644 index 0000000000..65d05d0d4e --- /dev/null +++ b/boost/geometry/strategies/geographic/buffer_side_straight.hpp @@ -0,0 +1,119 @@ +// Boost.Geometry + +// Copyright (c) 2022 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_SIDE_STRAIGHT_HPP +#define BOOST_GEOMETRY_STRATEGIES_GEOGRAPHIC_BUFFER_SIDE_STRAIGHT_HPP + +#include <cstddef> + +#include <boost/range/value_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 +{ + +namespace strategy { namespace buffer +{ + +/*! +\brief Create a straight buffer along a side, on the Earth +\ingroup strategies +\details This strategy can be used as SideStrategy for the buffer algorithm. + */ +template +< + typename FormulaPolicy = strategy::andoyer, + typename Spheroid = srs::spheroid<double>, + typename CalculationType = void +> +class geographic_side_straight +{ +public : + //! \brief Constructs the strategy with a spheroid + //! \param spheroid The spheroid to be used + explicit inline geographic_side_straight(Spheroid const& spheroid) + : m_spheroid(spheroid) + {} + + //! \brief Constructs the strategy + inline geographic_side_straight() + {} + +#ifndef DOXYGEN_SHOULD_SKIP_THIS + // Returns true if the buffer distance is always the same + static inline bool equidistant() + { + return true; + } + + + template + < + typename Point, + typename DistanceStrategy, + typename RangeOut + > + inline result_code apply(Point const& input_p1, Point const& input_p2, + buffer_side_selector side, + DistanceStrategy const& distance_strategy, + RangeOut& range_out) const + { + using calc_t = typename select_calculation_type + < + Point, + typename boost::range_value<RangeOut>::type, + CalculationType + >::type; + + using helper = geographic_buffer_helper<FormulaPolicy, calc_t>; + + calc_t const lon1_rad = get_as_radian<0>(input_p1); + calc_t const lat1_rad = get_as_radian<1>(input_p1); + calc_t const lon2_rad = get_as_radian<0>(input_p2); + calc_t const lat2_rad = get_as_radian<1>(input_p2); + if (lon1_rad == lon2_rad && lat1_rad == lat2_rad) + { + // Coordinates are simplified and therefore most often not equal. + // But if simplify is skipped, or for lines with two + // equal points, length is 0 and we cannot generate output. + return result_no_output; + } + + + // Measure the angle from p1 to p2 with the Inverse transformation, + // and subtract pi/2 to make it perpendicular. + auto const inv = helper::azimuth(lon1_rad, lat1_rad, input_p2, m_spheroid); + auto const angle = math::wrap_azimuth_in_radian(inv - geometry::math::half_pi<calc_t>()); + + // Calculate the distance and generate two points at that distance + auto const distance = distance_strategy.apply(input_p1, input_p2, side); + helper::append_point(lon1_rad, lat1_rad, distance, angle, m_spheroid, range_out); + helper::append_point(lon2_rad, lat2_rad, distance, angle, m_spheroid, range_out); + + return result_normal; + } +#endif // DOXYGEN_SHOULD_SKIP_THIS + +private : + Spheroid m_spheroid; +}; + +}} // namespace strategy::buffer + +}} // namespace boost::geometry + +#endif // BOOST_GEOMETRY_STRATEGIES_GEOGRAPHIC_BUFFER_SIDE_STRAIGHT_HPP |