C++ R - tree implementation wanted

Question

Does anyone know a good and simple to use in production code R-tree implementation? (actually, any implementations - R*, R+ or PR-tree would be great)

It doesn't matter if it is a template or library implementation, but some implementations that Google found look very disappointing...

Answer 1

You may also check out the rtree variants provided by the Boost.Geometry library:

http://www.boost.org/doc/libs/release/libs/geometry/doc/html/geometry/spatial_indexes.html

Boost.Geometry rtree implementation allows storing values of arbitrary type in the spatial index and performing complex queries. Parameters like maximum node elements may be passed as compile- or run-time parameters. It supports C++11 move semantics also emulated on pre-C++11 compilers thanks to Boost.Move. It also supports stateful allocators which allows e.g. to store the rtree in a shared memory using Boost.Interprocess. And it's fast.

On the down-side, currently persistent storage isn't yet supported so if you need more than in-memory spatial index you should probably check one of the other mentioned libraries.

Quick example:

Probably the most common use case is when you store some geometric objects in a container and their bounding boxes with some ids in the spatial index. In case of Boost.Geometry rtree this could look like this:

#include <boost/geometry.hpp>
#include <boost/geometry/index/rtree.hpp>
#include <vector>

namespace bg = boost::geometry;
namespace bgi = boost::geometry::index;

/* The definition of my_object type goes here */

int main()
{
    typedef bg::model::point<float, 2, bg::cs::cartesian> point;
    typedef bg::model::box<point> box;
    typedef std::pair<box, size_t> value;

    std::vector<my_object> objects;

    /* Fill objects */

    // create the R* variant of the rtree
    bgi::rtree< value, bgi::rstar<16> > rtree;

    // insert some values to the rtree
    for ( size_t i = 0 ; i < objects.size() ; ++i )
    {
        // create a box
        box b = objects[i].calculate_bounding_box();
        // insert new value
        rtree.insert(std::make_pair(b, i));
    }

    // 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));

    return 0;
}