[mkgmap-dev] Question about splitter and ways going in and out of atile

Fri Jul 29 15:04:29 BST 2011

The splitter has a command line parameter called --overlap which defaults 
to 2000. If a node falls within this many map units of a tile edge, it will 
still be included in that tile. You could try increasing this to a larger 
number to see if it solves your problem.

Failing that, the starting point for this logic is in SplitProcessor.writeNode(). 
The call to OSMWriter.nodeBelongsToThisArea() determines whether or not a 
node is written out to a particular tile. SplitProcessor.writeWay() is where 
the ways are queued up for writing.

Regards,
Chris

> Dear all,
> 
> I'm currently building a contour map for france and spain from srtm
> data (with strm2osm or gdal tools).
> I'd like to use splitter to divide the huge osm file I produced.
> However I've got a problem with contour lines getting in and out of  a
> tile and any help would be appreciated.
> I've tried to split similar tiles with osmosis and think the behavior
> in splitter is the same as in Osmosis with (or without anyway)
> clipIncompleteEntities.
> Ie when the way is written to a given tile, the nodes outside of the
> tile are dismissed.
> But now the way has a straight line between the point where the way
> gets out of the tile to the point where it gets back in.
> I managed to modify Osmosis so that it splits the way into different
> parts (just adding a somewhat random value to the way id, so that it
> does not collide with other ids), rather than writing a unique way
> with outside nodes dismissed.
> I'd like to know how splitter writes the ways into the different tiles
> and where to look in the source code so that I can easily modify the
> code and implement a similar behavior.
> Regards,
> 