Calling interested Glamo OpenGL developers (was: The forbidden topic: Glamo OpenGL)

Carsten Haitzler (The Rasterman) raster at
Thu Nov 20 23:16:15 CET 2008

On Thu, 20 Nov 2008 19:00:02 +0100 "Nicola Mfb" <nicola.mfb at> babbled:

> 2008/11/18 The Rasterman Carsten Haitzler <raster at>
> > [...]
> > evas supports opengl too. no it doesn't have an advantage, as glamo won't
> > be
> > doing opengl at VGA (the resolution of the device) so you won't be doing it
> > for
> > normal 2D UI's (thus my comments of it being of limited use for some
> > fullscreen
> > games for example where you drop to QVGA for the game). also the 256x256
> > max
> > texture size leads to problems even if it could do VGA output.
> Oh this is a definitive limit, I would appreciate 3d acceleration to speedup
> everyday apps, and not some small 3d games, this is secondary for the
> freerunner actually.
> > > *) when necessary you can use directly Xlib because X is 2d accelerated ?
> >
> > you ALWAYS use xlib* - if you want to interact with x in any way.
> I mean, if my preferred toolkit does not advantages of hardware
> acceleration, I may use Xlib and call for example XCopyArea to do fast blits
> in video memory?

you can.

> I wrote a small code snippet to test XCopyArea performance, and it seems to
> do about 25fps smoothscrolling but at the cost of XGlamo using 70/80% of
> CPU. This seems very strange, it maybe my code is wrong (I repeat I'm not an
> expert :) ), or XCopyArea is not full accelerated, or Xglamo has to be
> optimized, or that the Glamo GPU is simply slow :)

it's accelerated - but likely polling the command queue status as you have no
interrupts thanks to the linux kernel's policy of not exporting interrupts to
userspace, so you're stuck with a poll loop. i can't remember if glamo had a
"i'm done" interrupt for the command queue or operations - i know it had
several interrupts it can generate (but as the kernel wouldnt allow userspace
to make use of them i pretty much ignored them).

------------- Codito, ergo sum - "I code, therefore I am" --------------
The Rasterman (Carsten Haitzler)    raster at

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