Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world.

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)

Either

`#include <boost/geometry.hpp>`

Or

`#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;
"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))
```