[OSM-talk] Mapnik handling of highways that are also landuse...

[Martijn van Oosterhout]

On Thu, Aug 28, 2008 at 8:47 PM, Jon Burgess <jburgess777 at googlemail.com> wrote:
>> FWIW, I've been planning to implement just that at some point, just
>> havn't gotten around to it yet. The biggest problem is that the style
>> file needs to contain information like "tag X applies only to
>> nodes/ways/areas" and this information simply does not exist.
>> Collecting this information is a project in itself.
>
> I did something similar to put the features into multiple tables but I
> didn't do any tag filtering. The tag filtering was not important at one
> time because there were no common rendering styles shared between linear
> and area features. Now some combinations like
> highway=pedestrian,area=yes make things things more complicated.

In case anybody is wondering, if you know tag X does not apply to
nodes ever, osm2pgsql supports that now. For the distinction between
lines and polygons there is an attempt but it doesn't quite work
right. What I want to do extend it to is that highway=traffic_signals
is only for nodes and highway=pedestrian only for ways.

> My personal opinion is that features like a road around an area should
> use different ways. When mapping features myself I don't even share the
> nodes. I find it much clearer to leave a small gap between the area and
> surrounding ways.

For stuff like name which can be applied to anything it will always
get copied to all objects. Being able to have multiple features out of
a single OSM object isn't ever going to be easy. But we can do things
much better than now...

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