[OSM-talk] area_with_holes as alternative to multipolygon relation

[Igor Brejc]

Ok, then please let me know when you finish this transition to the new 
system, so that I can update the Kosmos code. And it would be a good 
thing to include a description of a recommended logic for rendering on 
the http://wiki.openstreetmap.org/index.php/Relations/Multipolygon page, 
so that it is implemented consistently in all of OSM software.

Cheers,
Igor

Jon Burgess wrote:
> 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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