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

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

Converts one geometry to another geometry.

The convert algorithm converts one geometry, e.g. a BOX, to another geometry, e.g. a RING. This only if it is possible and applicable. If the point-order is different, or the closure is different between two geometry types, it will be converted correctly by explicitly reversing the points or closing or opening the polygon rings.

template<typename Geometry1, typename Geometry2> void convert(Geometry1 const & geometry1, Geometry2 & geometry2)

Type |
Concept |
Name |
Description |
---|---|---|---|

Geometry1 const & |
Any type fulfilling a Geometry Concept |
geometry1 |
A model of the specified concept (source) |

Geometry2 & |
Any type fulfilling a Geometry Concept |
geometry2 |
A model of the specified concept (target) |

`#include <boost/geometry/algorithms/convert.hpp>`

Tip | |
---|---|

convert is not defined within OGC or ISO |

Tip | |
---|---|

convert is modelled as source -> target (where assign is modelled as target := source) |

Linear

Shows how to convert a geometry into another geometry

#include <iostream> #include <boost/geometry.hpp> #include <boost/geometry/geometries/box.hpp> #include <boost/geometry/geometries/point_xy.hpp> #include <boost/geometry/geometries/polygon.hpp> #include <boost/geometry/geometries/adapted/boost_tuple.hpp> BOOST_GEOMETRY_REGISTER_BOOST_TUPLE_CS(cs::cartesian) int main() { typedef boost::geometry::model::d2::point_xy<double> point; typedef boost::geometry::model::box<point> box; typedef boost::geometry::model::polygon<point> polygon; point p1(1, 1); box bx = boost::geometry::make<box>(1, 1, 2, 2); // Assign a box to a polygon (conversion box->poly) polygon poly; boost::geometry::convert(bx, poly); // Convert a point to another point type (conversion of point-type) boost::tuple<double, double> p2; boost::geometry::convert(p1, p2); // source -> target using boost::geometry::dsv; std::cout << "box: " << dsv(bx) << std::endl << "polygon: " << dsv(poly) << std::endl << "point: " << dsv(p1) << std::endl << "point tuples: " << dsv(p2) << std::endl ; return 0; }

Output:

box: ((1, 1), (2, 2)) polygon: (((1, 1), (1, 2), (2, 2), (2, 1), (1, 1))) point: (1, 1) point tuples: (1, 1)