D14784: [scenes/opengl] Fix overlaps in shadow texture atlas

zzag added inline comments.

INLINE COMMENTS

> davidedmundson wrote in scene_opengl.cpp:2425-2426
> If left is wider than topleft then we'll end up with a gap between the topleft and top.
> 
> Personally I'd call that a corrupt data and not care, which is what the code currently does.
> But this whole patch is about handling corrupt shadows.
> 
> ---
> 
> We could either p.drawPixmap(QRect, QImage)  so it scales to fill the quadrant
> 
> or
> 
> p.drawPixmap( innerRectLeft - shadowElementTopLeft.width(), ....)
> 
> so that we align the topLeft element to the right of it's allocated rectangle.
> 
> (or the equivalent with style()->drawItemPixmap)

> If left is wider than topleft then we'll end up with a gap between the topleft and top.

Yes, there will be gap. That's fault of whoever provided such corrupted tiles, not ours.

Normally, the texture atlas won't have gaps between tiles.

I don't think that's good idea to stretch tiles. FWIW, plasma provides corner tiles that are bigger than left/top/right/bottom tiles (because of rounded corners).

REPOSITORY
  R108 KWin

REVISION DETAIL
  https://phabricator.kde.org/D14784

To: zzag, #kwin
Cc: davidedmundson, abetts, kwin, mkulinski, ragreen, jackyalcine, Pitel, iodelay, bwowk, ZrenBot, lesliezhai, ali-mohamed, hardening, jensreuterberg, sebas, apol, mart