Geometry Boost List: [ggl] Intersection/difference and mixed geometries

Subject: [ggl] Intersection/difference and mixed geometries
From: Barend Gehrels (barend.gehrels)
Date: 2011-01-31 04:22:42

Hi Bill,

> I am revisiting this because my latest experiments with boost-geometry-0.8.0 show that not all interesting intersection/difference combinations are supported.
>
> Given:
> 	MultiPoint MP1, MP2, MP;
> 	MultiLinestring ML1, ML2, ML;
> 	MultiPolygon MA1, MA2, MA;
>
> The following intersection combination compiles:
> 	bg::intersection(MA1, MA2, MA);
> However the following "interesting" intersections do not:
> 	bg::intersection(MP1, MA2, MP);
> 	bg::intersection(ML1, MA2, ML);
>
> Likewise for difference, the following combination compiles:
> 	bg::difference(MA1, MA2, MA);
> However the following "interesting" differences do not:
> 	bg::difference(MP1, MA2, MP);
> 	bg::difference(ML1, MA2, ML);

Indeed interesting.

> Any plans to get those implemented?

Yes, in the end I like to have them all implemented. So there are plans.

But for now I concentrate on get Boost.Geometry released... The overlay 
family then goes to areal features, as it was reviewed, but then all 
combinations (clockwise, counterclockwise, open, closed, intersection, 
union, difference, sym_difference, rings, polygons, multi_polygons, 
float, double, ttmath). Most (nearly all) of this is running, a few 
things have to be tested, and documentation finished.

Sorry for the inconvenience.

Regards, Barend