[OSM-talk] area_with_holes as alternative to multipolygon relation

Jon Burgess jburgess777 at googlemail.com
Mon Mar 10 22:22:51 GMT 2008


On Mon, 2008-03-10 at 22:51 +0100, Igor Brejc wrote:
> I too am a little bit confused: now the whole issue basically comes
> down 
> to renaming the relation from "multipolygon" to "area_with_holes". But
> the inital proposal had some other features, like using the inner 
> polygons' tags to render the inner polygons content directly (not as 
> holes) + abandoning clockwise/anticlockwise approach.

Right, it is exactly these sort of differences which require this to be
a new relation type (IMO).

> Is the renaming really necessary? I think the existing renderers
> already 
> know how to draw multipolygons even without outer/inner specification.

This is my point too. Don't break what already works. By all means
create a new relation to cover the new rules. The old type can be
depreciated and it is easy to know how many of the existing relations
have been validated and migrated to the new rules.

> > That may be what we want but a significant proportion of the
> existing
> > data also has:
> > 1) an outer ring which is not a single closed way
> > 2) the same tags on all of the ways
> Shouldn't this be handled just by fixing the inconsistent data?
> 
Point (2) is actually a feature of the existing multipolygons. Changing
this retrospectively will break things. 

	Jon






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