[OSM-dev] Area support

[Frederik Ramm]

Hi,

Stefan Keller wrote:
> The XML encoding we are talking about is about data exchange between two 
> systems. Geospatial data especially has the property to be "write once, 
> read many times".

But the database would still identify nodes by ID, so if the editor 
uploads a changed area to the database, it must upload the IDs of the 
nodes in question; specifying the actual node coordinates is useless at 
that point.

> To be precise, we need a common understanding what is a 
> valid area/polygon geometry type conceptually (I propose to say, that 
> non-overlapping polygons is an additional constraint). I could give 
> precise definitions (in wrods and figures) on that. Then the eoncoding 
> comes in.

Currently we have a soft upper limit on how complex objects we're 
willing to process. Ways and areas with more than 1.000 points are not 
liked - they do exist but are usually split up if encountered. We will 
perhaps require some way to describe an object that is "part of an area 
outline"; we do this with coastlines currently, they exist as many small 
ways but together form the continent areas.

Bye
Frederik

-- 
Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00'09" E008°23'33"