[OSM-dev] GSoC - Data Tile Service

[Peter Wendorff]

Am 25.05.2012 02:23, schrieb Michael Daines:
>> * Problem: Since we are speaking about "vector tiling" it's
>> unavoidable that polygons are clipped, which makes me wonder on how
>> the client is informed and how he should deal with this?
> I'm not sure if I have a complete answer for that yet. Do you have any suggestions?
>
> One possibility is to do what the API does for bbox queries, where complete geometry for ways with a node intersecting the tile is included, and also the relations which refer to the stuff in the tile, but that's it. (So if you have a tile intersecting with the border of a country, you don't get the entire border, just one part of it.)
AFAIK osm polygons don't have a fixed drawing direction, they may be 
drawn clockwise or counter-clockwise.
Including a part of the polygon only would therefore not be enough, as 
the consumer cannot decide how to draw that part anyhow filled without 
being able to decide about which side of the line is inside and which is 
outside.

regards
Peter