Sally's Summit Summary

[Frank Warmerdam]

On 6/20/05, Paul Ramsey <pramsey at refractions.net> wrote:
> Steve,
> Thanks for the summary, I am sorry I missed the summit, but the Twins
> were playing so we did baseball instead.
> 
> - Paul Spencer and I also talked about "magic projection" support. Many
> formats have projection information embedded or alongside, so having to
> redundently specify them in the map file is not the most user-friendly
> approach. Like the "wms_extent", projection blocks should really only be
> required "as necessary". I think this can be done relatively easily, by
> adding some projection setting code into the LayerOpen area of each
> driver, and agreeing on some heuristics:
> 
> o If there is a PROJECTION in the map file, then don't overwrite it.

Paul, 

I would note that there is already PROJECTION "AUTO" support in
the OGR and GDAL driver code for MapServer.  But it only kicks in
if the user requests "AUTO" as the projection.

I am a bit leery about doing it without the user requesting it for
fear that the system detect very slightly different coordinate systems
(ie NAD83 and WGS84) that would cause alot of unnecessary 
reprojection work.  I believe that is why the "AUTO" keyword was
required in the past. 

I would however like to see more automatic projection support working
more widely in mapserver.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent