Hello List;
While checking my flow-graph I discovered the following problem with the
“WX
GUI FFT Sink” in
GnuRadio-Companion.
When the flow graph is running and you try to check the “Persistance”
box
you get the following error:
Traceback (most recent call last):
File
“/usr/local/lib/python2.6/dist-packages/gnuradio/wxgui/plotter/plotter_base.
py”, line 192, in _on_paint
GL.glAccum(GL.GL_LOAD, 1.0)
File “/usr/lib/pymodules/python2.6/OpenGL/error.py”, line 194, in
glCheckError
baseOperation = baseOperation,
OpenGL.error.GLError: GLError(
err = 1282,
description = 'invalid operation',
baseOperation = glAccum,
cArguments = (GL_LOAD, 1.0)
)
There are no errors at build time .
Has anyone seen this? I could have sworn it was working OK before.
Bill
I’ve seen that as well, and as far as I know, it has to do with
something deep in the bowels of OpenGL, and not directly related to
Gnu Radio specifically–it’s just that our “stuff” provokes it.
I’ve noticed that as well, have for years. So, I just don’t use
persistence.
On 05/15/2012 05:32 PM, William Pretty Security wrote:
When the flow graph is running and you try to check the “Persistance” box
you get the following error:
Been happening for me for years now. I dont think the persistence is one
of those cross GL features. Only available on some GPU cards, like
nvidia. The sink could stand to have a graceful try/except though…
-josh
Discuss-gnuradio Info Page
Sweet jesuit crispies on a leprotic camel. “Persistence” is a fairly
simple operation. Why, I ask rhetorically, in holy heck, should it
require
GD GPU support? And if the GPU doesn’t support it, GL can’t do it in
fakking software? I used to think GL was cool, now I think it’s
a festering sore, a blight on the landscape, a miserable piece of
ill-considered flotsam, bobbing up and down on a cesspool of its own
creation, a putrescent mound of worthless troll spittle.
–
Marcus L.
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
On Tue, May 15, 2012 at 6:01 PM, Marcus D. Leech [email protected]
wrote:
https://lists.gnu.org/mailman/**listinfo/discuss-gnuradiohttps://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Sweet jesuit crispies on a leprotic camel. “Persistence” is a fairly
simple operation. Why, I ask rhetorically, in holy heck, should it require
GD GPU support? And if the GPU doesn’t support it, GL can’t do it in
fakking software? I used to think GL was cool, now I think it’s
a festering sore, a blight on the landscape, a miserable piece of
ill-considered flotsam, bobbing up and down on a cesspool of its own
creation, a putrescent mound of worthless troll spittle.
Gee, Marcus. Tell us what you really think. 
–n
It’s not OpenGL, it’s badly designed OpenGL drivers, saying OpenGL
sucks is like saying C is slow, it can with a bad implementation, but
by its self no. Back on topic, I too have had all sorts of problems
like this with WX FFT, but it’s a different error on each OS on each
system 0_o. I have to just use Baudline for my FFT ( much more useful
IMHO, but not open source 
)
Gee, Marcus. Tell us what you really think.
–n
I edited myself considerably 
–
Marcus L.
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
Someone reads a lot of Dickens and Douglas Adams…
It’s not OpenGL, it’s badly designed OpenGL drivers, saying OpenGL
sucks is like saying C is slow, it can with a bad implementation, but
by its self no. Back on topic, I too have had all sorts of problems
like this with WX FFT, but it’s a different error on each OS on each
system 0_o. I have to just use Baudline for my FFT ( much more useful
IMHO, but not open source 
)
Well, if OpenGL simple turns every rendering task I ask it to do and
defers to the hardware, then it isn’t much good as a Graphics API.
If, however, it’s intended to simply be a universal API for rendering
hardware, then perhaps it’s not appropriate to use it at all for
simple, uncomplicated, 2D tasks such as those asked of it by Gnu
Radio.
But if OpenGL is intended to be an environment for rendering various
graphical concepts, using whatever optimizations happen to be
available to it, or not, then it fails.
–
Marcus L.
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
On 05/15/2012 08:29 PM, Andrew D. wrote:
It’s up to the driver writer to handle missing components properly,
Mesa has a full software OpenGL stack, I never thought about it but
i’ll try using that and see what errors I get.
I would like to be wrong, but as I recall, persistence was a non
standard thing. So drivers don’t even bother to emulate it.
-josh
Success, with a pure software renderer WX FFT works. Not sure why the
Intel graphics drivers doesn’t play nice, but I don’t think the WXGUI
code is to blame ( not that I doubted you :). OP try switching drivers
and see what happens.
On Wed, May 16, 2012 at 11:30 AM, Nowlan, Sean
It’s up to the driver writer to handle missing components properly,
Mesa has a full software OpenGL stack, I never thought about it but
i’ll try using that and see what errors I get.
Success, with a pure software renderer WX FFT works. Not sure why the
Intel graphics drivers doesn’t play nice, but I don’t think the WXGUI
code is to blame ( not that I doubted you :). OP try switching drivers
and see what happens.
Hmm, I wonder what the effects on performance will be?
How do you get the Mesa renderer installed on Linuxoid systems?
Been happening for me for years now. I dont think the persistence is
Principal Investigator
Discuss-gnuradio mailing list
[email protected]
Discuss-gnuradio Info Page
Discuss-gnuradio mailing list
[email protected]
Discuss-gnuradio Info Page
–
Marcus L.
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
Hi Marcus, etc.
If I may make a suggestion:
Is there any way to remove/disable the “Persistence” check box from that
block??
At least until the OpenGL problem is fixed or what ever ??
Bill
Hello All;
Thanks for all the feedback (wow!) …
Sounds like I’m hosed
I’ll just tell the client not to use “Persistence” for the time being
…
Marcus: How is that ulcer of yours doing? Have you tried decaf ?
Later;
Bill
3D performance on everything else sucked, but the FFT was exactly the
same, I think it always uses software for line drawing, just the
software in the GPU drivers isn’t as good as the full software driver.
To switch, just change the driver line in your xorg.conf, I changed
mine to " Driver “vesa” ", which changes the OpenGL stack to Mesa’s
full software renderer.
Andrew;
I did a “find -name” in my GnuRadio directories and couldn’t find any
xorg.conf file.
I found a number of xorg.conf files, but none that seem to relate
specifically to GnuRadio …
Do I have to create one ??
Bill
https://wiki.archlinux.org/index.php/Xorg#Monitor_settings
This section should work for any modern X environment.
What we really need to do is find a way to just tell OpenGL to use
software only, I remember something about this from my video game days
( the GL in my email ) but cant seem to remember how…
On 17/05/12 19:33, William Pretty Security wrote:
I did a “find -name” in my GnuRadio directories and couldn’t find any
xorg.conf file.
I found a number of xorg.conf files, but none that seem to relate
specifically to GnuRadio …
Do I have to create one ??
xorg.conf is a system-wide config file for the X server. You may have to
create one as modern systems auto-detect as much as possible in order to
avoid needing one. It has nothing to do with gnuradio.
alexd