On Fri, Jul 23, 2010 at 11:51, Richard Fairhurst <[email protected]>wrote:
> Chris Browet wrote: > > Zoom levels are fine (as an alternative, IMHO) if they are very clearly >> defined in a generic/projection agnostic manner AND if scales are defined >> too. >> The only generally "recognized" zoom levels are map scales (e.g. 1:5000) >> which are clear and precise for everyone. When you buy a printed map, the >> scale is not defined by a zoom level ;-) >> > > Yep, but most web maps are delivered in a tiled format into a > resolution-dependent browser. In other words, the renderer has no idea what > scale the map will be shown at. If I serve a bunch of standard 900913 tiles > at z15, I don't know whether the user will be looking at them on a 72dpi > monitor, a 96dpi monitor, or whatever - and that affects the scale. > > I'd suggest that we standardise on a choice of: > > |z13 - means standard 900913 zoom level > |s2500 - means 1:2,500 scale > > Renderers should support at a minimum the |s format; the |z format is > advisable if they are likely to be used in a web mapping context. Renderers > should make the best judgement as to scale/zoom mappings based on the > information available to them. > > Completely, 100%, agree. - Chris -
_______________________________________________ Mapcss mailing list [email protected] http://lists.openstreetmap.org/listinfo/mapcss
