[mapserver-dev] Axis order in WMS 1.3.0 (#3582)

[Martin Kofahl]

Hi,

in my mind MapServer still doesn't handle the axis order correctly for WMS 1.3.0 requests. The current implementation does first check a static list of epsg codes about axis orientation and otherwisely swap axes for epsg 4000-4999. (See http://trac.osgeo.org/mapserver/changeset/11155#file4, http://trac.osgeo.org/mapserver/browser/trunk/mapserver/mapaxisorder.csv?rev=11155)

Epsg codes with swapped axes commonly used in Germany are currently neglected and there are probably many more. As more and more WMS 1.3.0 clients come up, users get confused about WMS suddenly deliver a blank map (because of misinterpreted bbox).

MapServer makes the one who compiles MapServer responsible for the swapped-axis-codelist (mapaxisorder.csv). That's why I worry that there will be different MapServer 6 versions running with different handling of the axes order for identical requests.

The best would be to make MapServer axes-orientation-aware. Using the sql snippet from http://trac.osgeo.org/mapserver/ticket/3582#comment:13 I got about 1700 epsg codes with north/east (resp. south/west) axes, see http://trac.osgeo.org/mapserver/attachment/ticket/3582/mapaxisorder.h. I'm no expert in foreign epsg codes. From my understanding they all should be marked having swapped axes when processing WMS 1.3.0 requests. Someone who con confirm this? What about implementing the whole list into MapServer ... and hoping the best?

Best regards,
Martin