[mkgmap-dev] (almost) duplicated node issue

Mon May 25 21:34:30 BST 2009

Just a few thoughts...

1. Why not giving a special mark to such nodes which have been generated by a clipping process? Maybe there is own tag for this? Then you would know that merging is not appropriate.

2. And... please be careful when merging nodes which are parts of ways with different layers. These could represent separate floors of a public lift, e.g.

3. Is there special a tag for marking those nodes which must not be merged although they have the same coordinates? This tag could be used to prevent automatic merging.

-------- Original-Nachricht --------
> Datum: Mon, 25 May 2009 21:12:07 +0100
> Von: Mark Burton <markb at ordern.com>
> An: mkgmap-dev at lists.mkgmap.org.uk
> Betreff: Re: [mkgmap-dev] (almost) duplicated node issue

> 
> Hi Marco,
> 
> > I want to say: duplicated nodes and almost duplicated nodes are map
> errors (expecially if they describe an highway). We do not know wich was the
> right intention of the mapper (make routing possible/impossible).
> > 
> > I think that the best we can do when mkgmap finds 2 nodes that encode in
> the same IMG point (so in both cases: duplicated nodes or
> almost-duplicated nodes) is to collapse the 2 nodes in one node exacly as JOSM validator
> would do if they were duplicated.
> > 
> > Does it sound good?
> > 
> > Just my proposal...
> 
> I should think that it would be reasonably easy to merge close nodes
> using a first pass before any ways are processed.
> 
> However, tricky issues remain. Like, how do you cope with the situation
> of a node being generated by the clipping process and that node is
> within the critical distance of an existing node on the same way?
> 
> Cheers,
> 
> Mark
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