[PATCH] fb: Fix origin of source picture in fbGlyphs

Keith Packard keithp at keithp.com
Mon Apr 21 20:51:06 PDT 2014

Peter Harris <pharris at opentext.com> writes:

> On 2014-04-21 18:20, Keith Packard wrote:
>> Peter Harris <pharris at opentext.com> writes:
>>> If a source picture doesn't repeat and a mask format is specified, the
>>> incorrect calulation of the origin of the glyphs caused the glyphs to
>>> not be drawn at all.
>>> Noticed when running gtk-demo from RHEL 6.5 and selecting "Rotated
>>> Text".
>> Can you explain a bit more about how to reproduce this? I'm running the
>> gtk+2.0 gtk-demo app from the gtk2.0-examples debian package and not
>> seeing anything obviously incorrect?
> RHEL is about the only distribution us Debian users can call "outdated"
> with a straight face.
> Recent gtk-demo uses a solid (or at least repeating) source picture. The
> older gtk-demo used a non-repeating source picture with a width and
> height equal to that of the rotated text. I think the older gtk-demo is
> the only app I've ever seen in the wild that uses a non-repeating source
> picture.
> I just whipped up a minimal example; see attached. With miGlyphs (eg.
> before 9cbcb5bd6a5360a128d15b77a02d8d3351f74366) it draws a green X in
> the middle of the window. With fbGlyphs (before my patch), the window
> stays blank.

I've merged your fix and added your test app to the commit message so
that the next time we find that this is broken, we can make sure the fix
doesn't break this case again...

Who would have thought that with the only coordinate transform available
being translation that we'd have so many bugs because of it...

   ea15f8b..983e303  master -> master

keith.packard at intel.com
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