Raster to be the default Qt4 graphics engine @ Gentoo Linux

February 23, 2010 · Posted in Gentoo, Linux 

In our latest meeting[1] we decided to test and enable raster[2] use flag by default in Qt4. In order to achieve this, we kindly ask you to set this use flag on qt-gui and test as many Qt4 apps as you can. If you don’t feel like rebuilding qt-gui, you can simply append

-graphicssystem raster when launching a Qt4 application like this:

qmpdclient -graphicssystem raster 

You may also post your results on the respective topic on Gentoo forums[3]

Your feedback is much appreciated.

On behalf of the Gentoo Qt team, thank you

[1] http://gitorious.org/gentoo-qt/pages/Meeting20100219

[2] http://labs.trolltech.com/blogs/2008/10/22/so-long-and-thanks-for-the-blit/

[3] http://forums.gentoo.org/viewtopic-t-816758.html


22 Responses to “Raster to be the default Qt4 graphics engine @ Gentoo Linux”

  1. Mike Lothian on February 23rd, 2010 11:32 pm

    What about -graphicsystem opengl? I thought that was the way forward?

  2. eliasp on February 23rd, 2010 11:39 pm

    Please do this only for ~ builds – raster has still way too many problems – e.g. rendering Choqok and many other apps useless.
    I don’t think raster is yet stable enough for being the default graphicssystem.
    I’ve used raster some time ago with 4.6.0 and had a lot of trouble, so I switched back.

    Good luck on getting this beast stable!

  3. Markos on February 24th, 2010 12:29 am

    Of course. We wont touch the stable Qt ebuilds :)

    @ Mike

    Opengl is way more unstable. Almost every Qt4 app ( at least on my dev machine ) fails to launch when I use opengl

  4. Pavel on February 24th, 2010 12:42 am

    @Mike: AFAIK, opengl isn’t yet considered stable, so I guess that’d be the reason why to go for raster. But at some point opengl should be an option, couldn’t the graphics engine be eselected?

  5. Mike Lothian on February 24th, 2010 3:13 am

    I guess either eselelcted or use more USE flags to control the renderer

    The reason I asked about OpenGL is it’s going to take a lot of effort to get raster working, perhaps it would be better to get OpenGL working instead as I believe this is what Nokia / Qt guys are working on

  6. Kevin Bowling on February 24th, 2010 5:51 am

    What is prompting the change? Have you solicited upstream’s advice? What other distros have done or are considering this?

    It seems like a rash move based on numbers from over a year ago. The X11 backend is fine and has advantages when using ssh X tunneling or NX. I’d prefer we not deviate from the norm too far unless upstream recommends it or there is a very large win like with OpenGL rendering.

  7. Markos on February 24th, 2010 7:09 am

    I wouldn’t say that this is a rash move. This engine is there for over a year ago. And yes, it was very unstable at the beginning, but here we are, 18 months later, trying to figure out whether this engine is still unusable or not.

    If your feedback is negative we wont enable it by default. No need to clarify this :). But if you people believe that this engine is usable then I would like it to have it enabled by default.

    We are still in the feedback/discussion process. No decisions have been made yet

    @ all

    eselect seems like a good solution to me. I haven’t thought that to an end, so I have to discuss it with the rest of the team first :)

  8. [...] Raster to be the default Qt4 graphics engine @ Gentoo Linux [...]

  9. fate on March 2nd, 2010 8:28 pm

    No offense, Markos, but for me OpenGL is working without *serious* problems, that said, there are small glitches, like screen flashing when switching tabs in Konqueror but I’d call that mild annoying at most and it’s not like Konqueror was a terribly good web browser in the first place. Currently using KDE 4.4 on Linux 2.6.33 with nVidia’s binary blob 195.36.03.
    As for my laptop with Radeon integrated GPU and live open source driver: its OpenGL support is very flaky, therefore I’m using raster engine on it (yup, I like KDE4 so much, that I’m running it as my only DE even on a mere laptop) and, well, I don’t really feel much difference, apart from laptop being overall slower (which might or might not be related to CPU having to render GUI).

  10. fate on March 2nd, 2010 8:33 pm

    BTW, I’m using Chromium 5.0.340.0 (40230) and not that fruitware.

  11. Smorg on March 3rd, 2010 2:13 pm

    Something like an environment variable or eselect as Pavel mentioned in order to toggle which renderer is used at runtime would be ideal given the issue with NX and X11 forwarding. Raster

  12. Smorg on March 3rd, 2010 2:18 pm

    Something like an environment variable or eselect as Pavel mentioned in order to toggle which renderer is used at runtime would be ideal given the issue with NX and X11 forwarding. Raster makes it almost unusably slow, but also has performance advantages when running things locally. A toggle might be important so that someone logged in remotely can have their environment set to run QT programs with the native renderer while a local user can simultaniously run with raster without having to manually set the flag at the command line.

  13. Slavko on March 3rd, 2010 6:24 pm

    Dear sirs,

    i’m not sure how you are measuring the perfomance, but switching the default rendering to raster has changed my life. I see up to 3x performance in drawing for instance in krusader. The kind lord knows you shouldnt be able to see it with the plain eye but this is the state of linux graphics. (ok holding enter on a directory you can see how fast it redraws… raster is clearly faster)

    Going from 40%+ X cpu usage to max 5% AND FASTER DRAWING is something worth looking at and shows where the problem is.

    Opengl just doesnt seem as fast and works for only 70% of the apps but im hoping it will be finished soon:)

    Im just sorry that GTK doesnt have this (chromium:’( ).


  14. fate on March 3rd, 2010 8:06 pm

    Gravataron, as you should already know, hardware accelerated 3D is a mess on Linux. Depending on hardware, drivers, settings and app (not to mention direction of wind) it can outperform Windows, be utterly slow or just blow up spectacularly. At least state your GPU and driver used. Thanks.

  15. Non_E on March 4th, 2010 12:33 am

    Well, I am amazed it is already enabled on my box. No problems so far.

  16. Markos on March 4th, 2010 10:08 am

    I enabled it on my laptops’ 4.6.2 ( I used to use raster on 4.6.9999 packages only ). Everything looks fine with a minor performance boost. I use latest ~Xpackages and Intel drivers

  17. [...] USE flag is going to be on by default. Μάρκος (hwoarang) already blogged about this asking for [...]

  18. Mihai on March 15th, 2010 1:48 pm

    In my opinion, raster is not yet ready. I’m running latest ~amd64 (qt 4.6.2, xf86-video-intel) and I’m experiencing some issues: some fonts “jump” up and down in konsole when the cursor highlights them, konsole tab switching is noticeably slower and sometimes (once/twice a day) widgets seem to miss repaint events.

  19. Sven Eden on February 9th, 2012 11:16 am

    I second that. With xf86-video-intel (latest) all context menus (RMB) do not show up, I have to move the mouse over the area they should be to make them appear. I had to switch back to native. (With OpenGL not even kdm starts but crashes immediately. But that might be, because I am using EGL/GLES instead of OpenGL)

  20. Sven Eden on February 28th, 2012 3:38 pm

    A little update: Today I have upgraded to x11-drivers/xf86-video-intel-2.18.0 and media-libs/mesa-8.0.1 and can now use the new raster engine without any problems so far. *yay*

  21. Robson Peixoto on September 21st, 2012 11:19 am

    Is raster stable on currents qt’s versions ?

  22. Markos on October 2nd, 2012 7:46 am

    It should be!

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