[OSM-talk] The segments vs ways vs superways question again...

[Thomas Walraet]

bvh a écrit :
> On Wed, Jan 03, 2007 at 04:39:22PM +0100, Jochen Topf wrote:
>> Currently we can't do:
>>
>> - Areas with holes in them. Current hack around this: Define inner area
>>   with higher layer. Disjoint areas: Say several parking lots around a
>>   convention center that we want to tag together.
> 
> A client can easily order an unordered set of segments in two subsets:
> those forming the exterior and those forming the holes.

It doesn't seams so easy to me with the current data model.

As I say on another message, the client has to know for each area type 
if it's considered a hole in the water or not. And without orientation 
of the area border, you can't cope with incomplete data (coastline...)


> The datamodel
> does not need to express that information.

I think the data should represent the reality.

We approximate roads as lines. But for the water i think it's better to 
use oriented areas which could correctly represent the reality than to 
approximate it with a stack of layers for sea, continent, lake, island 
on lake, small lake on island, etc.