densify

Densify a geometry.

Synopsis

template<typename Geometry, typename Distance>
void densify(Geometry const & geometry, Geometry & out, Distance const & max_distance)

Parameters

Type	Concept	Name	Description
Geometry const &	Any type fulfilling a Geometry Concept	geometry	Input geometry, to be densified
Geometry &	Any type fulfilling a Geometry Concept	out	Output geometry, densified version of the input geometry
Distance const &	A numerical distance measure	max_distance	Distance threshold (in units depending on coordinate system)

Header

Either

#include <boost/geometry.hpp>

#include <boost/geometry/algorithms/densify.hpp>

Conformance

The function densify is not defined by OGC.

	Note
	PostGIS contains an algorithm ST_Segmentize with the same functionality. See the PostGIS documentation.

Behavior

The algorithm divides segments of a geometry if they are longer than passed distance into smaller segments.

	Note
	The units of the distance depends on strategy. In order to change the default behavior a user has to create a strategy and pass it explicitly into the algorithm.

Example

Shows how to densify a polygon

#include <iostream>

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

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

    polygon_type poly;
    boost::geometry::read_wkt(
        "POLYGON((0 0,0 10,10 10,10 0,0 0),(1 1,4 1,4 4,1 4,1 1))", poly);

    polygon_type res;

    boost::geometry::densify(poly, res, 6.0);

    std::cout << "densified: " << boost::geometry::wkt(res) << std::endl;

    return 0;
}

Output:

densified: POLYGON((0 0,0 5,0 10,5 10,10 10,10 5,10 0,5 0,0 0),(1 1,4 1,4 4,1 4,1 1))

Boost C++ Libraries