Geometry Boost List: Re: [geometry] "Boost.Geometry Overlay invalid input exception" in boost::geometry::sym_difference

Subject: Re: [geometry] "Boost.Geometry Overlay invalid input exception" in boost::geometry::sym_difference
From: Barend Gehrels (barend_at_[hidden])
Date: 2013-10-16 10:14:19

Hi Volker,

Volker Schöch wrote On 16-10-2013 12:59:
> Hi Barend,
> Thank you very much for looking into this!
>
>> I will have a look. Is there a ticket for this? No problem if there is not, I will look today, just to know.
> I did not yet file a ticket b/c if it's a known issue and/or resolved in 1.55, then I would just take your word for it and not clutter the bug database. If you think that it's an original issue that is not yet being worked on, I'll happily file a ticket.

The second polygon is not valid. It probably has a spike somewhere here:

If this polygon is generated using Boost.Geometry, this should be solved 
by 1.55 because we avoid generating spikes now, explicitly.

Otherwise we could remove the spike using remove_spikes (currently an 
extension), we can try to release that in 1.56

A third option is let the intersection process handle spikes correctly, 
but the results, and planning, of that are not yet sure.

Yes maybe it is good to file a ticket of this with this information.

Regards, Barend