Boost C++ Libraries

Let the buffer create rounded ends.

Description

This strategy can be used as EndStrategy for the buffer algorithm. It creates a rounded end for each linestring-end. It can be applied for (multi)linestrings. Also it is applicable for spikes in (multi)polygons. This strategy is only applicable for Cartesian coordinate systems.

Synopsis

class strategy::buffer::end_round
{
  // ...
};

Constructor(s)

end_round(std::size_t points_per_circle = 90)

Header

#include <boost/geometry/strategies/cartesian/buffer_end_round.hpp>

Example

Shows how the end_round strategy can be used as a EndStrategy to create rounded ends

#include <boost/geometry.hpp>
#include <boost/geometry/geometries/point_xy.hpp>
#include <boost/geometry/geometries/geometries.hpp>


int main()
{
    typedef boost::geometry::model::d2::point_xy<double> point;
    typedef boost::geometry::model::linestring<point> linestring;
    typedef boost::geometry::model::polygon<point> polygon;

    // Declare the round-end strategy with 36 points for a full circle
    boost::geometry::strategy::buffer::end_round end_strategy(36);

    // Declare other strategies
    boost::geometry::strategy::buffer::distance_symmetric<double> distance_strategy(1.0);
    boost::geometry::strategy::buffer::side_straight side_strategy;
    boost::geometry::strategy::buffer::join_round join_strategy;
    boost::geometry::strategy::buffer::point_circle point_strategy;

    // Declare/fill a multi linestring
    boost::geometry::model::multi_linestring<linestring> ml;
    boost::geometry::read_wkt("MULTILINESTRING((3 5,5 10,7 5),(7 7,11 10,15 7,19 10))", ml);

    // Create the buffered geometry with rounded ends
    boost::geometry::model::multi_polygon<polygon> result;
    boost::geometry::buffer(ml, result,
                distance_strategy, side_strategy,
                join_strategy, end_strategy, point_strategy);


    return 0;
}

Output

See also