Geometry Boost List: [geometry] Integrating OGR library with Boost.Geometry

Subject: [geometry] Integrating OGR library with Boost.Geometry
From: Eric MSP Veith (eveith_at_[hidden])
Date: 2015-01-07 12:34:56

[ Disclaimer: This is a cross-post; a similar question has been posted on 
stackoverflow.com: <http://stackoverflow.com/questions/27767656/how-to-register-a-boost-geometry-distance-strategy-for-ogrpoint-and-ogrlinestrin> ]

Hello list!

I am a first-time user of Boost.Geometry. My goal is to use Boost.Geometry's 
rtree implementation with OGRGeometry instances [0]. To that end, I've adapted 
the necessary OGR classes (OGRPoint, OGRLineString, OGRLinearRing and 
OGRPolygon) to Boost.Geometry's model. Iterating, etc. works good.

However, the current version of Boost.Geometry has no support for different 
map projections, which is why I'm forced to stick with OGRGeometry in general. 
Also, the existing codebase makes heavy use of the OGR* interfaces. 

What I am looking for is to use Boost.Geometry's tag/dispatch feature to call 
OGRGeometry::Distance() whenever I (or rtree) uses bg::distance(), 
OGRGeometry::Crosses() when bg::crosses() is used, and so an. Basically, the 
Boost.Geometry predicates are then nothing more than wrappers around the 
corresponding OGR* counterparts.

I've begun with bg::distance for OGRPoint to OGRPoint, and it worked. However, 
I'm stuck with bg::distance(OGRPoint &, OGRLineString &), with a compile 
error. My guess is that it stems from Boost.Geometry's concept of a 
linestring, which is nothing more than an ordered collection of points.

Is there any kind of template specialisation I can use so that a call to 
bg::distance(OGRGeometry const&, OGRGeometry const&) is dispatched to 
OGRGeometry::Distance(...)?

What follows is the template instanciation that makes me believe that my 
dispatching does not work due to a Boost.Geometry linestring being a 
collection of points, the full error message, and my current code:

---%<---
struct boost::geometry::strategy::distance::services::default_strategy<
        boost::geometry::point_tag,
        boost::geometry::segment_tag,
        OGRPoint,                           // NOTE: Twice OGRPoint!
        OGRPoint,
        MyCode::OGRCoordinateSystemTag,
        MyCode::OGRCoordinateSystemTag, void>
--->%---

The full error message is:

--->%---
In file included from 
/usr/include/boost/geometry/strategies/strategies.hpp:30:0,
                 from /usr/include/boost/geometry/geometry.hpp:43,
                 from /usr/include/boost/geometry.hpp:17,
                 from 
../../../winzent/test/simulation/OGRLineStringAdapterTest.cpp:7:
/usr/include/boost/geometry/strategies/distance.hpp: In instantiation of 
'struct 
boost::geometry::strategy::distance::services::default_strategy<boost::geometry::point_tag, 
boost::geometry::segment_tag, OGRPoint, OGRPoint, 
Winzent::Simulation::boost::OGRCoordinateSystemTag, 
Winzent::Simulation::boost::OGRCoordinateSystemTag, void>':
/usr/include/boost/geometry/algorithms/detail/distance/default_strategies.hpp:57:8:   
required from 'struct 
boost::geometry::detail::distance::default_strategy<OGRPoint, OGRLineString, 
boost::geometry::pointlike_tag, boost::geometry::linestring_tag, false>'
/usr/include/boost/geometry/algorithms/detail/distance/default_strategies.hpp:73:8:   
required from 'struct 
boost::geometry::detail::distance::default_strategy<OGRLineString, OGRPoint, 
boost::geometry::linestring_tag, boost::geometry::pointlike_tag, true>'
/usr/include/boost/geometry/strategies/distance_result.hpp:60:8:   required 
from 'struct boost::geometry::resolve_strategy::distance_result<OGRLineString, 
OGRPoint, boost::geometry::default_strategy>'
/usr/include/boost/geometry/strategies/distance_result.hpp:79:8:   required 
from 'struct boost::geometry::resolve_variant::distance_result<OGRLineString, 
OGRPoint, boost::geometry::default_strategy>'
/usr/include/boost/geometry/strategies/distance_result.hpp:199:8:   required 
from 'struct boost::geometry::distance_result<OGRLineString, OGRPoint, 
boost::geometry::default_strategy>'
/usr/include/boost/geometry/strategies/distance_result.hpp:205:8:   required 
from 'struct boost::geometry::distance_result<OGRLineString, OGRPoint, void>'
/usr/include/boost/geometry/strategies/default_distance_result.hpp:35:8:   
required from 'struct boost::geometry::default_distance_result<OGRLineString, 
OGRPoint>'
/usr/include/boost/geometry/algorithms/detail/distance/interface.hpp:392:1:   
required by substitution of 'template<class Geometry1, class Geometry2> 
typename boost::geometry::default_distance_result<Geometry1, Geometry2>::type 
boost::geometry::distance(const Geometry1&, const Geometry2&) [with Geometry1 
= OGRLineString; Geometry2 = OGRPoint]'
../../../winzent/test/simulation/OGRLineStringAdapterTest.cpp:71:62:   
required from here
/usr/include/boost/geometry/strategies/distance.hpp:97:456: error: no matching 
function for call to 'assertion_failed(mpl_::failed************ 
(boost::geometry::strategy::distance::services::default_strategy<boost::geometry::point_tag, 
boost::geometry::segment_tag, OGRPoint, OGRPoint, 
Winzent::Simulation::boost::OGRCoordinateSystemTag, 
Winzent::Simulation::boost::OGRCoordinateSystemTag, 
void>::NOT_IMPLEMENTED_FOR_THIS_POINT_TYPE_COMBINATION::************)
(mpl_::assert_::types<OGRPoint, OGRPoint, 
Winzent::Simulation::boost::OGRCoordinateSystemTag, 
Winzent::Simulation::boost::OGRCoordinateSystemTag>))'
     BOOST_MPL_ASSERT_MSG
---%<---

And this is my current attempt on a distance strategy:

---%<---
namespace boost {
    namespace geometry {
        namespace detail {
            namespace distance {

                template <>
                struct default_strategy<
                        OGRPoint,
                        OGRLineString,
                        pointlike_tag,
                        linestring_tag,
                        false>
                {
                    typedef OGRPointToLineStringDistanceStrategy type;
                };
            } // namespace distance
        } // namespace detail
    } // namespace geometry
} // namespace boost
--->%---

Thanks a lot in advance for any hints!

Kind Regards,
Eric

[0] http://www.gdal.org/classOGRGeometry.html