On Thursday 04 July 2013, Tirkon wrote: > [...] > The first priority for rendering could be the admin level. Within the > admin level at first the towns with a capital tag are rendered wirh a > star next to the name. If this is space-kompetitiv at a given zoom > level, the winner will be decided on the population. Then all other > towns of the given admin level are rendered. Space-competition is > decided first on the place tag (which could indicate independent > cities) and then on population.
The problem about this is not how to do it in principle but that label placement optimization is a highly non-local problem so doing it well requires doing it for the whole globe at once and you would have to redo it every time something changes anywhere. Even the current very simple approach suffers from this problem resulting in occasional cut off labels at tile edges. The thing is the standard osm.org map is meant to allow near real time updates and compromises rendering quality for that. But there is very little actual real time data in the rendering at the lowest zoom levels anyway - none in 0 and 1, only labels in 2 and 3. Frederik's approach would bring the real time osm data to the lower zoom levels but in the end only few of the individual changes in the database have a visible effect on the map at this scale. So it would make sense to take a split approach to the lower zoom levels - create a real time version that allows reviewing edits made to the database and a second high quality version that is pre-rendered periodically using techniques that can be more expensive. Greetings, -- Christoph Hormann http://www.imagico.de/ _______________________________________________ talk mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk
