On Wed, 2010-03-24 at 09:50 -0600, Christopher Stevens wrote: > Back to my original issue, here's some troublesome sample XML > (simplified, and for all zoom levels I think but still having the same > issue): > > <Map bgcolor="#00264c" srs="+proj=latlong +datum=WGS84"> > <Style name="point style 7"> > <Rule> > <Filter>[zoom] >= 0</Filter> > <PointSymbolizer file="./images/sys10-3px.png" height="3" > type="png" width="3" /> > </Rule> > </Style> > <Layer name="layer 8" srs="+proj=latlong +datum=WGS84" > status="on"> > <StyleName>point style 7</StyleName> > <Datasource> > <Parameter name="type">shape</Parameter> > <Parameter name="file">./solarSystemsLayer</Parameter> > </Datasource> > </Layer> > </Map> > > As is, I get a blank blue image. If I remove the following line, I get > my dots on an image: > <Filter>[zoom] >= 0</Filter> > > This is when viewing through tilecache. Is there an argument I can > pass in a python script to test out zoom levels? Does zoom level > specific data need to be in the shapefile itself (guessing no)? Am I > using wrongly formatted code? >
Zoom levels don't work like this in Mapnik. It has no concept of fixed zoom levels, it calculates a 'ScaleDenominator' based on the geographic bounding box and the pixel dimensions of the image. Each filter can have minimum and maximum scale value. For more details see: http://trac.mapnik.org/wiki/ScaleAndPpi http://trac.mapnik.org/wiki/MinScaleDenominator To see how the OpenStreetMap zoom levels map to the Mapnik scale values: http://trac.openstreetmap.org/browser/applications/rendering/mapnik/zoom-to-scale.txt Jon _______________________________________________ Mapnik-users mailing list [email protected] https://lists.berlios.de/mailman/listinfo/mapnik-users
