Version 4.4.1 dependency and/or linux platform dependency?

[Frank Warmerdam]

On 4/21/05, Brian Davis <bdavis at usgs.gov> wrote:
> When I zoom in to a map, the four corner points of my rubber-band box
> are the new corners for the data displayed in my 400x200 browser space.
> So, if I define an area that is 2:1 in x size to y size, I zoom in
> as expected.  But when defining space that is not this 2:1 rectangular
> ratio, the data gets stretched/contracted/distorted to fit that space,
> because the corners of my new definition become the drawn corners,
> instead of extra data in either the x or y direction being used to
> fill the the remaining area.

Brian,

As I understand it, the problem you are seeing is that MapServer
used to expand the region you requested as needed in order to
ensure square pixels, and now does not resulting in distorted
results, is that right? 

Indeed, for MapServer 4.4 there was "nonsquare" support
added to MapServer.  In WMS mode this is on by default, 
in order to comply with the specification.  In non-WMS mode
it is supposed to be off by default (giving you the traditional 
aspect preserving behavior) unless you add the following 
line to your .map file:

  CONFIG MS_NONSQUARE YES

Is your client requesting data via WMS?  If so, then you
will pretty much have to pre-adjust your bounding box to 
match the aspect ratio of the image size.  If you are getting
this behavior in traditional MapServer cgi mode and haven't
defined MS_NONSQUARE then we should look into what is 
going on.  

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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and watch the world go round - Rush    | Geospatial Programmer for Rent