[geos-devel] "self intersecting" polys

[Martin Davis]

Um...  If you mean what I think you mean by "zero-width corridor
polygons" (ie. The case in question) - well, depends what you mean by
"easy".  There's no mystery about the machinery, and all the pieces are
there in JTS/GEOS, but there's a certain amount of bookeeping required
to keep everything straight.  Especially if you want to handle a series
of ZWC's all touching one another...

Martin Davis, Senior Technical Architect
Vivid Solutions Inc.      www.vividsolutions.com
Suite #1A-2328 Government Street Victoria, B.C. V8T 5G5
Phone: (250) 385 6040 - Local 308 Fax: (250) 385 6046


> -----Original Message-----
> From: Paul Ramsey [mailto:pramsey at refractions.net] 
> Sent: September 2, 2004 4:02 PM
> To: GEOS Development List
> Subject: Re: [geos-devel] "self intersecting" polys
> 
> 
> Yes, we all look forward to the magical MakeValid() method :) 
> For the relatively simple case of Zero-Width-Corridor polygons, it 
> should be easy to write a function that separates out the holes from 
> hulls, yes?
> P.
> 
> Martin Davis wrote:
> > Unfortunately I can't think of an easy way to convert 
> > self-intersecting polygons to valid JTS/GEOS polygons using the 
> > current API.  This might be a useful function to have in 
> the future, 
> > however.
> > 
> > Martin Davis, Senior Technical Architect
> > Vivid Solutions Inc.      www.vividsolutions.com
> > Suite #1A-2328 Government Street Victoria, B.C. V8T 5G5
> > Phone: (250) 385 6040 - Local 308 Fax: (250) 385 6046
> > 
> > 
> > 
> >>-----Original Message-----
> >>From: Chris G. Nicholas [mailto:cgn at globexplorer.com]
> >>Sent: September 2, 2004 3:37 PM
> >>To: geos-devel at geos.refractions.net
> >>Subject: [geos-devel] "self intersecting" polys
> >>
> >>
> >>How difficult would it be for GEOS to support so-called "self
> >>intersecting" polygons - i.e. those with a common vertex. 
> >>Must we explode this sort of thing into a huge number of 
> >>overlapping polygons?
> >>
> >>thanks!
> >>
> >>Chris Nicholas
> >>GlobeXplorer
> >>
> >>
> >>
> > 
> > _______________________________________________
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> > geos-devel at geos.refractions.net 
> > http://geos.refractions.net/mailman/listinfo/geos-devel
> 
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