Re: [Traverso-devel] line based audio painting in cvs

[Nicola Döbelin]

Am Dienstag, 8. Januar 2008 21.46:20 schrieb Remon:
> Stumbled by accident on some performance related painting stuff today, so I
> figured, let's dump it here.
>
> Some ideas, in respect to nvidia and xorg. Do you have EXA or XAA enabled
> as acceleration architecture ?

After digging in xorg.conf and messing with different options, I noticed that 
Mandriva added the following line to the section "Device" by default:

Option "RenderAccel" "false"

Maybe because they use Metisse or Compiz by default. There's a warning about 
possible texture problems in the corresponding option in the control centre. 
Removing this option in xorg.conf (or checking the box "Activate RENDER 
acceleration (may lead to texture errors)" in the X-Server configuration of 
the Control Centre) makes Traverso paint PERFECTLY SMOOTH! Xorg load drops to 
1% and Traverso load to 3% for playback.

Some more info about my system:

- nVidia Corporation NV36.1 [GeForce FX 5700 Ultra] (rev a1), 128 MB
- NVidia driver version: 100.14.19
- Display resolution 1680x1050 (60Hz)
- Window manager: KWin 3.5.7

I don't know about EXA or XAA, but the Device section in my xorg.conf looks 
like this now:

Section "Device"
    Identifier "device1"
    VendorName "nVidia Corporation"
    BoardName "NVIDIA GeForce FX - GeForce 8800"
    Driver "nvidia"
    Option "DPMS"
    Option "AddARGBGLXVisuals"
EndSection

> What I wonder about now is, should I remove the line based painting, it's
> not a 'lower cpu using' alternative for polygon based painting, and imho it
> looks ugly :)
> It adds to the code that needs to be maintained, and jet another option
> which most users won't find or use anyways....?

I would definitely remove the option from the settings dialog and default to 
whatever you like more. Maybe you want to leave the code there for a little 
while, e.g. until Qt 4.4 is released. If you then still prefer the other 
solution, it's probably safe to remove the obsolete painting method from the 
sources.

> Last but not least, we should probably mention these problems somewhere,
> and if certain settings improve the real bad performance issue, list it as
> a possible solution.

Hehe, if the solution is as simple as shown above... But there's probably a 
reason for Mandriva to default to RenderAccel=false. Maybe people using 
composite WMs experience problems and have to decide between a composite WM 
or smooth painting in Traverso.

Greetings
Nic