On Jun 4, 2010, at 11:16 AM, Jon Burgess wrote: > On Fri, 2010-06-04 at 08:50 -0700, Dane Springmeyer wrote: >> I've been wondering if we need to switch to clipping (the extents used >> to determine layer intersection in feature_style_processor.cpp) by map >> extent (rather than layer extent), while adding the ability to >> manually set the MAX_EXTENT in the <Map /> section of an xml (in the >> target projection). This method would open the door to bogus (and >> unprojectedable) extents being passed to proj4 based on the map bbox, >> but hopefully most situations could be prevented using a MAX_EXTENT >> variable, which could be auto-calculated from each layer if not set >> (http://trac.mapnik.org/ticket/506). >> > > I have been thinking about a different solution. If there was some way > to mark the layer extent as 'all' or 'world', then the stage which > projects the layer extent to the target srs & applies the clipping could > be skipped entirely. This would be simple to implement and should avoid > all these issues.
What is the default behavior of Mapnik here? I've repeatedly run into extent/estimate_extent issues, most recently yesterday. I've managed to develop the right calluses around this stuff, but I find myself explaining it as magic to other users. It seems useful for Mapnik to assume "world" in most if not all cases. -mike. ---------------------------------------------------------------- michal migurski- [email protected] 415.558.1610 _______________________________________________ Mapnik-users mailing list [email protected] https://lists.berlios.de/mailman/listinfo/mapnik-users
