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Zengar
04-07-2003, 12:42 PM
Where should I report bugs I encounter in nVidia drivers? I've got some already http://www.opengl.org/discussion_boards/ubb/wink.gif

Zengar
04-08-2003, 10:51 AM
Ignoring, huh?
Don't like the idea of having bugs in your drivers? http://www.opengl.org/discussion_boards/ubb/wink.gif

I know you can hear me! http://www.opengl.org/discussion_boards/ubb/biggrin.gif

vincoof
04-08-2003, 11:24 AM
There are locations at http://developer.nvidia.com where you can give some feedback.

Otherwise you can post in this forum your problem of what you call a bug. If you've made a mistake, we'll probably help you find it. If it really is a bug, someone from nVidia will certainly reply to the thread, especially if the topic title contains "NV" or "GeForce" in it http://www.opengl.org/discussion_boards/ubb/wink.gif

Zengar
04-08-2003, 11:34 AM
Oh, I posted my problem in the beginners forum, but I never got a reply. Ok, I can repeat it.

So, the problem is ARB_vertex_program. As everybody knows, this extensions allows us to specify vertex data as attributes via glVertexAttribxx or glVertexAttribPointer.
But now look:
I disable vertex program, running the fixed-function pipeline.
glVertexAttribxx works great, but trying to pass data via attribute array results in black screen.
But, I enable vertex program - and suddenly it starts to work!

So I mean: is it not funny?? Driver developers should decide if they allow support for vertex attributes during vp disabled, or not. But this support should be complete: it's rather stupid that I can use per-vertex functions but not the arrays.
For me, vertex attributes functions are alternative possibility for standart vertex functions, and I will prefer them to be aviable all the time: I don't like redefining my vertex arrays with different API when I want to enable/disable vp. I mean, it's nothing complicated, but it makes program quite unreadable.

Asgard
04-08-2003, 11:45 AM
Actually, I'd consider it a bug that the glVertexAttrib-calls work when VP mode is disabled. There is no defined interaction of the generic vertex attributes of ARB_v_p with the fixed-function pipeline.

Zengar
04-08-2003, 11:47 AM
I guess you are right...

B.T.W. From today I will always insert 'NV' in my topic names!

vincoof
04-08-2003, 01:09 PM
Sorry Zengar, I didn't notice your thread in the beginners forum.

Actually, I do not think it is a driver bug. It is a strange behaviour, but not a bug.

The ARB_vertex_program specification define that generic vertex attributes can be used by vertex programs, so it is absolutely normal that it works correctly with vp enabled.

But the specification also mandates that setting a generic vertex attribute sets undefined the corresponding conventional vertex attribute, and vice versa.

from the spec :
For example, setting the current normal will leave generic vertex attribute 2 undefined, and vice versa.

So, when vertex programs are disabled, calling glVertexAttrib may or may not work, you don't know. It goes to glVertexAttribPointer either. But it is not specified that "the chosen behaviour for one may apply for the other". In other words, since the behaviour is undefined : don't play with it !



it's rather stupid that I can use per-vertex functions but not the arrays.
It seems stupid, but in fact it's simply a good example of what "undefined" means.



For me, vertex attributes functions are alternative possibility for standart vertex functions, and I will prefer them to be aviable all the time: I don't like redefining my vertex arrays with different API when I want to enable/disable vp.
If you use glVertexAttrib, I guess you're using vertex attributes out of the scope of conventional vertex attributes. If so, it means that you send vertex attributes that are never used when vp is disabled, and so forth you fill the pipeline with useless data. If not, it means that you don't need glVertexAttrib and it that case you can simply use glNormal/glColor/etc and you will have an unified interface whether vp is enabled or disabled.



Actually, I'd consider it a bug that the glVertexAttrib-calls work when VP mode is disabled.
I would not consider it a *bug* but I agree it would be a good thing if the driver didn't accept glVertexAttrib when VP is disabled. Though, it would go against the specification, so...



B.T.W. From today I will always insert 'NV' in my topic names!
LOL you're right http://www.opengl.org/discussion_boards/ubb/smile.gif Would you enter a topic if the title contained the word 'Zengar' ? I guess I know the answer.

I think it's not fair but you may also ask for NVIDIA in the advanced forum. As far as I can remember, I've never seen an NVIDIA post in the beginners forum. (note: this goes to ATi too http://www.opengl.org/discussion_boards/ubb/wink.gif)

[This message has been edited by vincoof (edited 04-08-2003).]

JD
04-08-2003, 09:56 PM
I had good luck with Sim from nvidia. Try emailing him if you have problems.

SDietrich@nvidia.com

From my memory there's also a bug feedback page at www.nvidia/developer (http://www.nvidia/developer) site I think.

Zengar
04-09-2003, 02:45 AM
Thanks, vincoof!