Because of performance problems I had a look at the X11 requests
generated by QT.
Basically it seems QT doesn't use any advanced XRender stuff, although
these days XRender acceleration is very good.
However by doing a lot of stuff on its own, a lot of GetImage requests
are required - which is quite a solution for todays EXA/UXA drivers
which try to keep pixmaps in vram.
- Does client-side gradients
- A lot of GC state changes.
- Does mix&match X11-GC and XRender which is quite often a *bad* idea.
Although this was fast with XAA, most of these operations cause
software-fallbacks these days.
- Doesn't support image transformations
- Doesn't support image repeat patterns
- As far as I've seen ARGB pictures aren't supported either.
Are there plans to improve the X11 backend?
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