Geometry Boost List: [ggl] incorrect result for an intersection

Subject: [ggl] incorrect result for an intersection
From: Simonson, Lucanus J (lucanus.j.simonson)
Date: 2011-04-16 14:27:46

Arash Partow wrote:
> Barend Gehrels wrote:
>> The input is reported as invalid by both SQL Server and PostGIS
>> ("Self-intersection[447765 503335]"). 
>> 
> 
> I'm curious to know why GPC is not used as the gold standard?

GPC will happily accept self intersecting polygons and produce garbage output without letting you know the output is bad.  Also, GPC is not numerically robust, nor is it even close to the optimal algorithm and would be too slow to use on large inputs even if it were reliable enough to handle them.  GPC isn't a gold standard for anything given that it falls short in three significant ways.

Regards,
Luke