Hi Jukka, On 5/9/11 5:36 AM, Jukka Rahkonen wrote:
In addition to these native relation based polygons we have them also as true polygon features. Polygons are created automatically from the linestrings by a database operation. Polygons are automatically updated if the lines are edited and topology checks are preventing the operation if edits would lead to a non-valid polygon topology.
We do this in our post-processing too, but the results are mixed. Since the map is basically drawn as painted layers, it's very common to find a border-delineating feature (like a road that forms the edge of a park) not having the same path (either the same nodes or the same actual positions) as the park multipolygon. The result are very small slivers of polygons along the edges of features.
As a result, we've had to put in a bunch of code to 'sanitize' the topological-polygon results for our users.
cheers ben -- Scenery Home Page: http://scenery.x-plane.com/ Scenery blog: http://www.x-plane.com/blog/ Plugin SDK: http://www.xsquawkbox.net/xpsdk/ X-Plane Wiki: http://wiki.x-plane.com/ Scenery mailing list: [email protected] Developer mailing list: [email protected] _______________________________________________ dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/dev
