Re: [Discuss-gnuradio] Use of OpenGL in gr-qtgui

[Moeller]

On 27.03.2011 10:10, Alexandru Csete wrote:
>> If they do, then are the Qt widgets equally-likely to provoke some of the
>> horrible problems I've seen with the OpenGL in
>>  WxWidgets used in Gnu Radio?
>> The OpenGL "eco-system" seems to break randomly, even for apparently-correct
>> applications, particularly when the DRM
>>  is used in the X server, but only on certain hardware.  This makes it

It did not work with a remote X server (Xming) on Windows XP.
(missing X extensions) So I had to switch it off.

>>  eco-system, but if Qt in turn uses OpenGL to render certain things, then
>> perhaps that's not a wise thing to do?

Is it needed for 2D acceleration? I didn't see any 3D graphics in Gnuradio.
I saw OpenGL in the waterfall plot code. Perhaps there are no standard
X functions for accelerated 2D shifting and stretching raster graphics, right?
Btw, why are the spectral plots only stretched in X direction but not in Y?

> With the graphics framework available in recent Qt, the application
> can decide at runtime whether to use Open GL rendering or not.
> The qt-gui sink in GNU Radio uses Qwt so it is one level higher, still
> the constructor has the parameter "use_openGL" which defaults to true:
> qtgui_sink_c_sptr qtgui_make_sink_c (int fftsize, int wintype,
...
>                                    bool use_openGL=true,
>                                    QWidget *parent=NULL);

With wxgui this could be configured in ~/.gnuradio/config.conf:

[wxgui]
style=nongl