[mkgmap-dev] Distorted lines

Wed Feb 19 11:51:38 GMT 2014

Hi Andrzej,

seems that the garmin data is older.
Reg. polygon optimization:
When I started to implement that, I noticed problems with buildings
that share lines. Sometimes the lines were moved apart
because the algo optimized one poly after the other.
So I started to code that ShapeMergeFilter
which connects the polygon and removes points where possible.
The open problem now is that I merge the polys of each 
sub division. If I optimize them, I see again the "move apart"
problem at places where one poly is in one sub div and another 
neighbour poly is in a different sub div.
Maybe I can implement an algo that optimizes at least those 
polygons which can't share any points with others in other 
sub divisions with some kind of reference counter.
The correct solution that I have in mind requires a big 
change in data structures, so I'd like to postpone that
because I want to merge the branch to trunk first.

Gerd

popej wrote
> Hi Gerd,
> 
>  > Are you also satisfied with the results?
> 
> Sure, thanks. Railways look good.
> 
> I'm a bit worried about inconsistency. See this building:
> http://www.openstreetmap.org/way/256598227
> 
> I have attached screenshot building-mkgmap.png. On my map this building 
> is drawn as an outline and a polygon. I know that other people use this 
> kind of presentation too. I would preffer similar simplification for 
> polygons.
> 
> See building-garmin.png. Garmin is using more extreme simplification, 
> maybe even dedicated algorithm for buildings.
> 
> -- 
> Best regards,
> Andrzej
> 
> _______________________________________________
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> mkgmap-dev at .org

> http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
> 
> building-mkgmap.png (20K)
> &lt;http://gis.19327.n5.nabble.com/attachment/5796805/0/building-mkgmap.png&gt;
> building-garmin.png (17K)
> &lt;http://gis.19327.n5.nabble.com/attachment/5796805/1/building-garmin.png&gt;

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