MapScript's prepareImage() doesn't support non-square pixels

[dmorissette]

While working on bug 945, it was noted that MapScript's prepareImage (SWIG and
PHP) could not easily be made to support non-square pixels. This is a low
priority, but I'm filing this as an enhancement bug so that we don't forget.

Here is what I had written in bug 945:
> 
> Frank: I was not sure how to handle the MS_NONSQUARE thing inside
> msPrepareImage() since it requires that the caller should call
> msMapRestoreRealExtent() when he's done. With scripts calling
> $map->prepareimage() there is no way to guarantee that this would happen. To
> resolve the issue quickly, I simply added a allow_nonsquare boolean which is
> set to MS_FALSE from MapScript, and is set to MS_TRUE when called from 
> msDrawMap().
> Could you please review what I've done and tell us if it would be possible to
> allow mapscript to call prepareimage with nonsquare pixels and get rid of my
> allow_nonsquare hack?

[dmorissette]

Setting FUTURE target milestone. This is definitely not a priority for 4.4

[akrherz@…]

Hi,

For what it is worth, it would be nice to see this feature supported.  Are there
any updates?

thanks,
  daryl

[sgillies@…]

Daryl, also check out bug 1645. Frank suggested a solution that doesn't seem to
be working for that reporter. I tried something similiar a few months ago also
without success. Nonsquare pixels is controlled by several parameters and I
haven't hit the right combination yet.

[sgillies@…]

Disregard comment #3. As long as layers have projections, the MS_NONSQUARE
config option is all that's needed.