Re: [boost] [GGL] Is this a bug, or undocumented behavior?

Subject: Re: [boost] [GGL] Is this a bug, or undocumented behavior?
From: Barend Gehrels (barend_at_[hidden])
Date: 2009-11-22 19:04:17

Hi Jonathan,

Jonathan Franklin wrote:
> I have been running some of my own polygon union test cases on the
> union_inserter.  The union_inserter doesn't appear to return a minimal
> set.  E.g. if the start point of a polygon appears in the union, it
> will appear twice (consecutively).
>
> Is this expected behavior?  If so, it should probably be documented.
> I have some other algorithms which expect a sequence of unique points,
> so I would need to pre-process the result of this function call.
>   
>
Good question. This was a known problem, in our tests we're currently 
running "simplify" to remove them.
It should have been documented as known problem, sorry. The intention is 
to return a minimal set.

Instead of simplify you can also call std::unique (as in one of the 
samples) on the rings of the output polygons, this will help (but  I 
agree, inconvenient now).

Regards, Barend