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[mkgmap-dev] Splitting at country borders?

From Johann Gail johann.gail at gmx.de on Sun Sep 20 22:13:01 BST 2009

> neither splitter or osmosis insert new points. but it is required to  
> have boundary nodes in mkgmap. splitter would need to calculate  
> crossing points with the boundary or a provided split polygon with all  
> ways and insert the boundary points.
This is my opinion too. Whatever tool does the splitting into countries, 
it has to create new nodes at the intersection of the roads and the 
state borders.
> you can do the presplit but routing can't work then across boundaries.
> osmosis has different modes
> - clip ways at the boundary -> no routing across tiles due to missing  
> nodes
As I'he written before, I don't know the internals of osmosis. But if I 
the ways are clipped at a border, then it should be possible to create a 
new node at the intersection and mark the node as a border node.
Is there a developper of osmosis reading this list?
>>> Then it would be possilbe to download europe from geofabrik, split it
>>> into countries and then crate maps from it.
>>> These maps would be interroutable. It would be also need less  
>>> computing
>>> power/memory for doing this compared of
>>> processing the whole europe map
>> I would expect the interstate routing to work. Precondition is  
>> obviously
>> that the presplitted tiles don't miss any segments at the border and  
>> the
>> border nodes have exactly the same coordinates.
> still don't understand why this is useful. If you want multiple  
> countries and route across countries and tiles why split it more than  
> necessary and try to assemble again?
As some other users have written, then it would be possible to download 
the regions of interest from geofabrik and compile them with splitter 
and mkgmap and have a routable map.
Then its not neccessary to download whole europe, when I want only 
bavaria and austria. I could furthermore load the precompiled maps of 
countires onto my etrex, just as I need them.

So I would really appreciate it, if the presplitted maps from geofabrik 
are clipped 'correctly' at the borders.

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