[mkgmap-dev] special case where splitting fails without a log message

Tue May 25 12:36:36 BST 2021

Hi Gerd

I'm getting very confused by this. When I build with my trunk (some
filter order changes + a few others), I see a whole lot more that JOSM
shows. It and your 6324001.img just show a central bit. Looking with
GPSMapEdit with "Highlight Polygon Contours". I also see areas where
all islands are inverted.

I'll undo my trunk changes and look again.

Does JOSM have self-intersection checking?

Was the gpx trace hi-res (30bit) and then this kept when generating the
osm. If not, then I'd expect problems.

Ticker

On Tue, 2021-05-25 at 11:18 +0000, Gerd Petermann wrote:
> Hi Ticker,
> 
> I didn't investigate the details. I've created the osm data by
> converting a gpx back to osm. I guess in the original input duplicate
> points are identical. I found more such cases where parts are
> removed.
> 
> Gerd
> 
> 
> ________________________________________
> Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag
> von Ticker Berkin <rwb-mkgmap at jagit.co.uk>
> Gesendet: Dienstag, 25. Mai 2021 12:51
> An: Development list for mkgmap
> Betreff: Re: [mkgmap-dev] special case where splitting fails without
> a log message
> 
> Hi Gerd
> 
> OK - I've reproduced this. Is split-failed.osm self-intersecting? I'm
> not sure how to tell from Josm, but it looks like it isn't. I get the
> messages from shapeSplitter because it thinks it is and then the
> result
> is not good - as expected.
> 
> I'll investigate more.
> 
> Ticker
> 
> 
> On Tue, 2021-05-25 at 10:04 +0000, Gerd Petermann wrote:
> > Hi Ticker,
> > 
> > while looking at the problems with sea I found this case where
> > ShapeSplitter removes a small part of an island from a self
> > -intersecting polygon in res 24.
> > Compiled with mkgmap from trunk, default style and no options.
> > 
> > Look at 67.6742611, 14.6783525
> > 
> > Found this with some check code that compares the area of the
> > original polygon with that of sum of the parts.
> > 
> > Gerd
> > _______________________________________________
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> > mkgmap-dev at lists.mkgmap.org.uk
> > https://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
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