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template<typename Geometry, typename Distance> void densify(Geometry const & geometry, Geometry & out, Distance const & max_distance)
| 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) | 
Either
            #include <boost/geometry.hpp>
          
Or
            #include <boost/geometry/algorithms/densify.hpp>
          
The function densify is not defined by OGC.
| ![[Note]](../../../../../../../../doc/src/images/note.png) | Note | 
|---|---|
| PostGIS contains an algorithm ST_Segmentize with the same functionality. See the PostGIS documentation. | 
The algorithm divides segments of a geometry if they are longer than passed distance into smaller segments.
| ![[Note]](../../../../../../../../doc/src/images/note.png) | 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. | 
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))