Martin,

I just hope I didn't confuse you with the "screen coordinates" stuff. From
an Emacs users point of view (and from the point of view of elisp) the
UPPER LEFT corner is 0x0 -- as it is on every other system. The fact that
OS X see everything from the lower left corner is handled by internally by
"nsterm.m". Hence, there is no need to mention this in the manual.

"Flipping" mean that the coordinate system is mirrored, in some way. I
guess it could be used to set the upper left as the origin, but I'm not
that into OS X to tell you how that is done and what other consequences
that would have for the Emacs code base.

Unfortunately, I have no idea why it worked in 24.5 and why it didn't in
25. There has been a lot of changes along the way, so one would have to
inspect each one to see what changed, and why.

/ Anders

On Sun, Sep 20, 2015 at 10:44 AM, martin rudalics <rudalics@gmx.at> wrote:

> > I've attached the patch, sorry for posting it in the mail.
>
> Thank you.  Keith please try it.  If it fixes all remaining issues I'll
> try to commit everything we have now next week.
>
> > You can read more about "screen coordinates" here:
> >
> >
> https://developer.apple.com/library/ios/documentation/General/Conceptual/Devpedia-CocoaApp/CoordinateSystem.html
>
> Thanks.  I'm slightly confused, at least - I have no idea what flipping
> means.  Can you have a short look at the section "Frame Geometry" in the
> Elisp manual?  Maybe I should mention something about this issue there.
>
> And do you have any idea why this apparently worked in Emacs 24.5 and
> doesn't work with present master/trunk?
>
> martin
>