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Subject: [ggl] Considering GEOS
From: Mateusz Loskot (mateusz)
Date: 2009-04-15 16:33:16

Barend Gehrels wrote:
> Hi Mateusz,
>> When I found GGL and started to work with it, I got an idea of
>> porting some of GEOS [1] algorithms to GGL.
> Actually I had seen that and had to think about it. Personally I
> don't think it is really useful to us. Our approach is totally
> different from theirs.

Yes, I'm aware of that.

> In the past I've looked to some implementations (not GEOS but e.g.
> geometryalgorithms). It is possible but in the end they turn out to
> be completely rewritten. It is justed an "influence" like reading an
> article.

I've been thinking of looking at some solutions,
constructions, algorithms and re-implement them completely,
according to GGL approach.

> Besides that I'm afraid that if we "copy" GEOS code we'll also get (a
> part of) its performance.

It is possible.

> Finally there is the license issue.


> It might seem attractive because they have much more (= all OGC)
> operations implemented. However, if we continue the step of the new
> segment intersection, together with the (completely revised) steps in
> the polygon clip (Weiler Atherton graph traversal), we have
> touch,overlaps,intersects,relate,disjoint,equals,intersection,union
> and buffer all implemented so it then becomes really useful.

Absolutely, I can see this potential.

> More about this will follow.

OK, no rush.

Best regards,

Mateusz Loskot,
Charter Member of OSGeo,

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