...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
#include <boost/geometry.hpp> #include <boost/geometry/geometries/point.hpp> #include <boost/geometry/geometries/box.hpp> #include <boost/geometry/index/rtree.hpp> #include <cmath> #include <vector> #include <iostream> #include <boost/foreach.hpp> #include <boost/shared_ptr.hpp> namespace bg = boost::geometry; namespace bgi = boost::geometry::index; namespace boost { namespace geometry { namespace index { template <typename Box> struct indexable< boost::shared_ptr<Box> > { typedef boost::shared_ptr<Box> V; typedef Box const& result_type; result_type operator()(V const& v) const { return *v; } }; }}} // namespace boost::geometry::index int main(void) { typedef bg::model::point<float, 2, bg::cs::cartesian> point; typedef bg::model::box<point> box; typedef boost::shared_ptr<box> shp; typedef shp value; // create the rtree using default constructor bgi::rtree< value, bgi::linear<16, 4> > rtree; std::cout << "filling index with boxes shared pointers:" << std::endl; // fill the spatial index for ( unsigned i = 0 ; i < 10 ; ++i ) { // create a box shp b(new box(point(i, i), point(i+0.5f, i+0.5f))); // display new box std::cout << bg::wkt<box>(*b) << std::endl; // insert new value rtree.insert(b); } // find values intersecting some area defined by a box box query_box(point(0, 0), point(5, 5)); std::vector<value> result_s; rtree.query(bgi::intersects(query_box), std::back_inserter(result_s)); // find 5 nearest values to a point std::vector<value> result_n; rtree.query(bgi::nearest(point(0, 0), 5), std::back_inserter(result_n)); // display results std::cout << "spatial query box:" << std::endl; std::cout << bg::wkt<box>(query_box) << std::endl; std::cout << "spatial query result:" << std::endl; BOOST_FOREACH(value const& v, result_s) std::cout << bg::wkt<box>(*v) << std::endl; std::cout << "knn query point:" << std::endl; std::cout << bg::wkt<point>(point(0, 0)) << std::endl; std::cout << "knn query result:" << std::endl; BOOST_FOREACH(value const& v, result_n) std::cout << bg::wkt<box>(*v) << std::endl; return 0; }