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

— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards

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 | |
---|---|

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 | |
---|---|

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)