pyopengl-users

[PyOpenGL-Users] Works on OSX, fails on Linux

[Derakon <de...@gm...>]

I'm trying to port a program from OSX to Linux, so it can be run over
an SSH tunnel. I'm getting "invalid operation" errors when I call
glTexSubImage2D, though. I've trimmed the program down to a
more-or-less minimal program (still almost 200 lines) which still
exhibits the failure:

http://paste.ubuntu.com/611982/

Dependencies are PyOpenGL, numpy, and wx. I apologize for the very
inconsistent code style/formatting; this is a bit of a hodgepodge and
I'm cleaning it up as I get the chance.

I've pasted the error I'm getting at the end of this message. It's
occurring in some PyOpenGL-accelerate code. From my understanding,
this package isn't actually necessary; it just makes certain
operations faster. Is it possible to uninstall it? Googling around
doesn't show it being particularly straightforward to uninstall Python
packages, but perhaps this one's more self-contained?

Could it be that running over ssh -Y is what's giving me trouble? I'm
not really familiar with SSH tunneling in general and what it does to
the display. Before I started trimming down the program to make the
"minimal" version, I was actually semi-randomly getting assertion
errors in /usr/lib/libxcb-xlib.so (and when the assertions didn't show
up the app would just hang with nothing displayed).

Anyway, here's the error. Any advice would be appreciated. Thanks!

Traceback (most recent call last):
  File "editor.py", line 159, in OnPaint
    image.refresh()
  File "editor.py", line 52, in refresh
    GL.GL_LUMINANCE, GL.GL_SHORT, imgString)
  File "latebind.pyx", line 32, in
OpenGL_accelerate.latebind.LateBind.__call__ (src/latebind.c:559)
  File "wrapper.pyx", line 315, in
OpenGL_accelerate.wrapper.Wrapper.__call__ (src/wrapper.c:5196)
OpenGL.error.GLError: GLError(
	err = 1282,
	description = 'invalid operation',
	baseOperation = glTexSubImage2D,
	pyArgs = (
		GL_TEXTURE_2D,
		0,
		0,
		0,
		512,
		512,
		GL_LUMINANCE,
		GL_SHORT,
		'\x00\x00\x01\x00\x02\x00\x03\x00\x04...,
	),
	cArgs = (
		GL_TEXTURE_2D,
		0,
		0,
		0,
		512,
		512,
		GL_LUMINANCE,
		GL_SHORT,
		'\x00\x00\x01\x00\x02\x00\x03\x00\x04...,
	),
	cArguments = (
		GL_TEXTURE_2D,
		0,
		0,
		0,
		512,
		512,
		GL_LUMINANCE,
		GL_SHORT,
		'\x00\x00\x01\x00\x02\x00\x03\x00\x04...,
	)
)

Re: [PyOpenGL-Users] Works on OSX, fails on Linux

[Mike C. F. <mcf...@vr...>]

On 11-05-23 02:41 PM, Derakon wrote:
> I'm trying to port a program from OSX to Linux, so it can be run over
> an SSH tunnel. I'm getting "invalid operation" errors when I call
> glTexSubImage2D, though. I've trimmed the program down to a
> more-or-less minimal program (still almost 200 lines) which still
> exhibits the failure:
I'm pretty sure the problem is that you haven't properly bound your
texture for the refresh and as a result you are seeing an error due to
e.g. alignment or similar issues pushing your image parameters into
invalid territory.  I come to that conclusion by adding a
self.bindtexture() to your image class' refresh method, which eliminates
the errors and displays some gradients.  This kind of thing is common in
cross-platform OpenGL, one implementation happens to allow it, another
is more strict about the order of operations.  Linux, in particular, has
become far more stringent in recent years as to order of operations.

HTH,
Mike

-- 
________________________________________________
  Mike C. Fletcher
  Designer, VR Plumber, Coder
  http://www.vrplumber.com
  http://blog.vrplumber.com

Re: [PyOpenGL-Users] Works on OSX, fails on Linux

[Alejandro S. <as...@gm...>]

Hi Derakon,

On Mon, May 23, 2011 at 4:04 PM, Mike C. Fletcher <mcf...@vr...>wrote:

> I'm pretty sure the problem is that you haven't properly bound your
> texture for the refresh and as a result you are seeing an error due to
> e.g. alignment or similar issues pushing your image parameters into
> invalid territory.


I subscribe to Mike's comments. In line 159 you are forgetting to call
image.bindTexture() before calling image.refresh(). This might not be what
you intended.

Good luck,

Alejandro.-



-- 
http://alejandrosegovia.net

[PyOpenGL-Users] Fwd: Works on OSX, fails on Linux

[Alejandro S. <as...@gm...>]

Forwarding to PyOpenGL Users on behalf of Derakon ;)

Alejandro.-

---------- Forwarded message ----------
From: Derakon <de...@gm...>
Date: Mon, May 23, 2011 at 4:30 PM
Subject: Re: [PyOpenGL-Users] Works on OSX, fails on Linux
To: Alejandro Segovia <as...@gm...>


On Mon, May 23, 2011 at 12:22 PM, Alejandro Segovia <as...@gm...>
wrote:
> Hi Derakon,
> On Mon, May 23, 2011 at 4:04 PM, Mike C. Fletcher <mcf...@vr...>
> wrote:
>>
>> I'm pretty sure the problem is that you haven't properly bound your
>> texture for the refresh and as a result you are seeing an error due to
>> e.g. alignment or similar issues pushing your image parameters into
>> invalid territory.
>
> I subscribe to Mike's comments. In line 159 you are forgetting to call
> image.bindTexture() before calling image.refresh(). This might not be what
> you intended.

Yeah, this was the fix. Thanks, guys!

I found that the the assertion errors I was getting earlier had
something to do with my multithreaded viewer-update code. In normal
use the program has three separate windows showing different views of
a dataset; when the dataset updates I have to update all three
viewers, which I was doing in three separate threads. I guess
something about that isn't quite threadsafe, since while it worked
fine on OSX I had to revert to a sequential update for the Linux port.

Anyway, it's working now!

-Chris



-- 
http://alejandrosegovia.net