[OSM-dev] Multilingual Maps Overlays

Jon Burgess jburgess777 at gmail.com
Wed Jun 16 20:53:00 BST 2010


On Wed, 2010-06-16 at 14:57 +0200, Lennard wrote:
> > This seems like the most logical thing to do, although I'm curious how
> > much things would overlap since mapnik wouldn't know which language
> > layer is being shown to move things around a bit.
> 
> Mapnik doesn't move things around to fit.
> 
> And quite a lot of overlap, actually. The text overlay places text where
> it sees fit, without taking any of the base map symbols/positioning into
> account. It's most apparent when at the highest zooms, in dense areas with
> lots of POIs.

I think that only applies to objects which use the point placement
method. For road labels it uses 'line placement' and this will move a
label if it finds the first position overlaps with another one. This is
important for gridded road layouts, e.g. compare the intersection of
William & Monument streets in Mapnik and Osmarender:
http://www.openstreetmap.org/?lat=-32.00572&lon=115.76109&zoom=17&layers=B000FTF

It is not an iterative approach, it does not go back and try updating
the position of labels which have already been placed.

	Jon






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