|  | Home | Libraries | People | FAQ | More | 
Densify a geometry using a specified strategy.
template<typename Geometry, typename Distance, typename Strategy> void densify(Geometry const & geometry, Geometry & out, Distance const & max_distance, Strategy const & strategy)
| 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 strategy) | 
| Strategy const & | A type fulfilling a DensifyStrategy concept | strategy | Densify strategy to be used for densification | 
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 linestring in geographic coordinate system
#include <iostream> #include <boost/geometry.hpp> #include <boost/geometry/geometries/point.hpp> #include <boost/geometry/geometries/linestring.hpp> int main() { namespace bg = boost::geometry; typedef bg::model::point<double, 2, bg::cs::geographic<bg::degree> > point_type; typedef bg::model::linestring<point_type> linestring_type; linestring_type ls; bg::read_wkt("LINESTRING(0 0,1 1)", ls); linestring_type res; bg::srs::spheroid<double> spheroid(6378137.0, 6356752.3142451793); bg::strategy::densify::geographic<> strategy(spheroid); boost::geometry::densify(ls, res, 50000.0, strategy); std::cout << "densified: " << boost::geometry::wkt(res) << std::endl; return 0; }
Output:
densified: LINESTRING(0 0,0.249972 0.250011,0.499954 0.500017,0.749954 0.750013,1 1)