[mkgmap-dev] Multipolygon-Relation checks in mkgmap

Thu Jan 26 08:42:24 GMT 2017

Hi Ticker,

the overlap is produced by the RoundCoordsFilter at res 20. This is quite normal and the algo should be able to handle
them. The alternative would be to change the the filter(s) so that they don't produce self- intersecting polygons.

Gerd

________________________________________
Von: Gerd Petermann
Gesendet: Mittwoch, 25. Januar 2017 16:22:05
An: Development list for mkgmap
Betreff: AW: [mkgmap-dev] Multipolygon-Relation checks in mkgmap

Hi Ticker,

okay, I'll have a look at the branch. The problem  in http://www.openstreetmap.org/relation/2199651
is solved with r3773, but your case looks different.

Gerd

________________________________________
Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag von Ticker Berkin <rwb-mkgmap at jagit.co.uk>
Gesendet: Mittwoch, 25. Januar 2017 15:56:06
An: mkgmap-dev at lists.mkgmap.org.uk
Betreff: Re: [mkgmap-dev] Multipolygon-Relation checks in mkgmap

Hi Gerd

Using your split of germany, 63240135.osm.pbf gives me the problem
after I converted PolygonSplitterBase and AreaClipper to the new algo

It is the outer way of relation/27312 at 48.94071,13.70245
At highest resolution, openStreetMap shows no intersection, but when I
dump the highRes points after the split complains and plot them it
shows an overlap.

Ticker

On Wed, 2017-01-25 at 14:29 +0000, Gerd Petermann wrote:
> Hi Ticker,
>
> do you have an example for such a problem case?
>
> Gerd
>
> ________________________________________
> Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag
> von Ticker Berkin <rwb-mkgmap at jagit.co.uk>
> Gesendet: Mittwoch, 25. Januar 2017 13:25:34
> An: mkgmap-dev at lists.mkgmap.org.uk
> Betreff: Re: [mkgmap-dev] Multipolygon-Relation checks in mkgmap
>
> Hi Gerd
>
> Yes - please
>
> I started looking at MultiPolygonRelation yesterday with a view of
> trying to convert it to use the new ShapeSplitter algorithm.
>
> I think that the way a self-intersecting polygon is rewritten after a
> split using the Java2D library causes problems for the new algorithm
> when it makes a later cut for points limits or subdivisions, even
> when
> the next cut isn't in the overlapped area.
>
> All I've done so far is convert a few more places to use highPrec
> logic
> and then slightly disparaging at the complexity of the whole thing.
>
> Ticker
>
> On Wed, 2017-01-25 at 09:05 +0000, Gerd Petermann wrote:
> > Hi all,
> >
> > I'd like to rewrite the code in MultiPolygonRelation so that it
> > tolerates more mp-rels.
> > For example, the relation
> > http://www.openstreetmap.org/relation/2199651
> > produces these warnings:
> > WARN: uk.me.parabola.mkgmap.reader.osm.MultiPolygonRelation
> >  f:\osm\rel2199651.osm: Some polygons are intersecting. This is not
> > allowed in multipolygons.
> > WARN: uk.me.parabola.mkgmap.reader.osm.MultiPolygonRelation
> >  f:\osm\rel2199651.osm: -
> > http://www.openstreetmap.org/way/165084794
> > WARN: uk.me.parabola.mkgmap.reader.osm.MultiPolygonRelation
> >  f:\osm\rel2199651.osm: -
> > http://www.openstreetmap.org/way/165084810
> > WARN: uk.me.parabola.mkgmap.reader.osm.MultiPolygonRelation
> >  f:\osm\rel2199651.osm: Polygon
> > 4611686018427387906(8P)(165084810[8P]) carries role inner but is
> > not
> > inside any other polygon. Potentially it does not belong to this
> > multipolygon.
> > The inner way touches the outer way in one point. My understanding
> > is
> > that this is correct, mkgmap should not complain about it.
> >
> >  OK?
> > Gerd
> >
> > _______________________________________________
> > mkgmap-dev mailing list
> > mkgmap-dev at lists.mkgmap.org.uk
> > http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
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