[OSM-talk] Mapnik & large rievrs

[Martijn van Oosterhout]

On Wed, Jun 11, 2008 at 3:58 PM, Andy Allan <gravitystorm at gmail.com> wrote:
> The more complex case, which I'm surprised hasn't been discussed at
> any point in this feature's development, is how I render a river with
> a polygon fill and a polyline riverbank (e.g. a dark blue line down
> each riverbank). As far as I see it osm2pgsql will have to do some
> complex pre-processing to make sure that the sections of riverbank
> which span the river (i.e. aren't actually river banks) don't get
> rendered when rendering an outline of the river.

If it ever gets decided to do riverbanks as just polylines instead of
complete polygons, the main effect will be that the processing will be
pushed out-of-line just like the coastlines are now. We'll have to
generate seperate riverbank shapefiles  for all the riverbanks which
with then have to be processed seperately in the stylesheet.

We support the usage of polylines for coastlines because we pretty
much have to. But PFTLOG don't do go suggesting polylines-for-areas
for everything just because it would be nice, because it really just
isn't nice at all...

polylines-joined-by-a-relation is cool, no problems there.

Have a nice day,
-- 
Martijn van Oosterhout <kleptog at gmail.com> http://svana.org/kleptog/