WMS: non square pixels performance

[Frank Warmerdam]

Eijnden, Bart van den (AGI) wrote:
> Hi Frank,
> 
> the data (shape file) can be downloaded from here (about 20 Mb):

Bart,

Whew, that is a big slow down!  It seems that the projection you are using
is very expensive computationally, and it was being applied twice per
point unecessarily so that the rescaling needed for non-square pixels could
be applied.

I have applied a change in mapproject.c to short circuit this reprojection
work that brings down the slow case to only about 50% more time than the
fast case.  If you can easily test with trunk or perhaps incorporate this
change into the source you are building from that would be appreciated.

   http://trac.osgeo.org/mapserver/changeset/6075

If it works well for you, I'd be inclined to incorporate this fix into
MapServer 4.10.2 but I'll need a ticket in trac to reference.

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    | President OSGeo, http://osgeo.org