On 05/04/2012 03:00 PM, Komяpa wrote: > 2012/5/1 Richard Fairhurst <[email protected]>: >> On 01/05/2012 14:47, Paul Hartmann wrote: >>> >>> In my opinion, it should be the same in MapCSS and the definition of the >>> zoom selector should be based on map scale rather than on the projected >>> coordinates in the Mercator projection. > > Here we come to usual problem: > - those who came from traditional maps think in scales; > - those who came from web-GIS think in zoom levels. > > There's no useful "scale" in EPSG:3857 - it changes depending on > latitude. So it is possible that renderer has to mix styles for > different scales in one screen.
This is maybe too drastic, I'd just take the scale of the centre pixel and use it for the entire mapcss styling process. > If you're using a different projection, and it's majorly different > from EPSG:3857, you have no "default" tiles grid. > > Do we have any real application now that uses not EPSG:3857 aka > Spherical Mercator for rendering? In JOSM you can switch to different projections, and this is often necessary in order to display aerial imagery from a local WMS. (On-the-fly warping isn't supported for WMS.) Spherical Mercator is just one projection of many and if it was the reference point, I'd had to put mapcss_scale = scale * cos(lat) somewhere in the display code, and this feels a bit arbitrary. On the other hand it is good, when the mapcss zoom levels correspond to the TMS levels, if they are displayed in the background. Paul _______________________________________________ Mapcss mailing list [email protected] http://lists.openstreetmap.org/listinfo/mapcss
