[OSM-talk] tagging and rendering highways in the USA and elsewhere

[Tom Hughes]

In message <1208544163.8530.34.camel at localhost.localdomain>
          Jon Burgess <jburgess777 at googlemail.com> wrote:

> Provided we have the polygons describing the boundaries of countries,
> states etc then we could tag the data during the osm2pgsql processing.
> Alternatively it might be possible for Mapnik to query them at run time
> (with the right join to a table containing boundary polygons in the data
> source SELECT line it might even be possible today).

I was thinking about that while I was walking home earlier. The
main question I guess is how efficient PostGIS is at answering
the question "which of these N hundred polygons is this data
in", or how efficiently we can code the equivalent in osm2pgsql.

> My main concern would be the maintainability of the osm.xml style file.
> It is already nearing 200kB and adding country (or state) specific
> rendering would make it even more complex.

Indeed. I was thinking about that too, and I think it needs an
extrat level of indirection, so the existing stylesheet stays
largely as it is but instead of saying that a secondary road
is rendered as #213455 or whatever some sort of code name is
given and then that is mapped to the real colour based on the
country.

Tom

-- 
Tom Hughes (tom at compton.nu)
http://www.compton.nu/