User defined spatial predicate within Boost Geometry

[Frank Hippmann <frank.hippmann@…>]

I need to determine whether the interiors of two geometries intersect. An InteriorsIntersect predicate is not specified by OGC or Boost Geometry but is defined by the DE-9IM matrix:

T * *
* * *
* * *

I've created my own predicate using the relate function in Boost Geometry.

namespace bgr = boost::geometry::detail::relate;
using InteriorsIntersectMask = bgr::static_mask<'T','*','*','*','*','*','*','*','*'>;

template<typename Geom1, typename Geom2>
inline bool interiorsIntersect(const Geom1& geom1, const Geom2& geom2)
{
    return bgr::relate<InteriorsIntersectMask>(geom1, geom2);
}

This works great. My only concern is that the relate function and static_mask type are not documented as part of the Boost Geometry API and are implementation details as far as I can tell. Is it safe to use relate in this way? Is there an alternative to achieving the same goal using Boost Geometry? Ideally I would like to see relate be an algorithm within boost/geometry/algorithms.

[awulkiew]

Yes, this was planned some time ago already. This is a GitHub pull request with the change: ​https://github.com/boostorg/geometry/pull/288

The interface is the same for run-time and compile-time masks.

namespace bg = boost::geometry;
using InteriorsIntersectMask = bg::de9im::static_mask<'T','*','*','*','*','*','*','*','*'>;

bg::relate(geom1, geom2, InteriorsIntersectMask());

Does it satisfy your needs?

[Frank Hippmann <frank.hippmann@…>]

Thanks, that's exactly what I am after.