Geometry Boost List: Re: [geometry] Segment to Segment Distance

Subject: Re: [geometry] Segment to Segment Distance
From: Barend Gehrels (barend_at_[hidden])
Date: 2012-05-21 15:46:00

Hi Dan,

On 19-5-2012 19:44, Dan Chianucci wrote:
> Hey guys,
>
> I'm trying to find the minimum distance between two segments, however 
> this feature doesn't seem to be supported
>
> http://www.boost.org/doc/libs/1_49_0/libs/geometry/doc/html/geometry/reference/algorithms/distance/distance_2.html
>
> Shows that this is true, however replacing the 1_49_0 with a 1_48_0 
> shows that it did in fact used to be supported.  I am currious as to 
> why this support was removed.  Or are the charts on the previous 
> version documentation incorrect?

Yes, sorry. The charts on previous version docs were not always correct. 
So segment-segment is not yet supported. Not that it is difficult, it is 
just not yet done. So it was also not yet there in 1.48

>
> It seems like the latter may be the case as the tables on the previous 
> versions site seem to be incorrect.

Yes, there were more incorrections in the previous version docs. They 
are enhanced now using another system of generation (thanks to Bruno).

>
> Eg.  Going down the MultiLineString column says that the distance 
> operation for MultiLineString can be computed against all other 
> geometries except Segment, Box and Ring.  However going across the 
> MultiLineString row says the only supported geometries are Point, 
> MultiPoint, and MultiLineString.

So yes, that was wrong too. If the matrix is not symmetric, it is 
(probably) incorrect. Currently the distance support matrix is symmetric 
and afaik correct.

Thanks, Barend