glXChooseVisual problem with nvidea quadro4 and RedHat8

[ilan_gr]

Does anyone has a clue?

the glXChooseVisual cannot open a proper visual on my computer.

When I tried to do the same with other computer that has, RedHat8 with Asus GeforceIII Ti200 it worked good.

I've installed the nvidia drivers has it was written in the instructions.

Please Help Me

[bwkaz]

What visual is it looking for?

What's available? (you can find out with glxinfo -t)

[ilan_gr]

???

[bwkaz]

I figured you'd know, since you've provided very little information in your post...

I was under the impression that you had written a program that used glXChooseVisual (since that was the function you referenced), that was failing to find a proper visual. That was how I thought you'd know "what it was looking for". I also figured that since (I thought) you had written the program, that you would know what to look for in the table.

But whether you are or aren't talking about a program you wrote, I really can't osmose what the program that's running is trying to do... ;)

If you didn't write a program, then what is going on?

[ilan_gr]

I wrote a program that basicly uses OpenGL on a glut interface.
The program has worked for about 3 years now on sgi-pc stations with sgi linux visual workstation.

when we upgraded two of our computers to P4, one with Asus Geforce3 Ti200 and one with Quadro4 Glx the problems with the glx command started to appear.

I'm using the glx command only to open a pixmap screen to dump it into a file and print it afterwards.
I don't realy know much in glx commands, i just copied the example from the openGL book (the green one for X systems)

The only thing i know is just that i tryied to open several screens, like, RGBA, DOUBLEBUFFER, STREO, but nothing worked(only on the Quadro4 system)

In the table I see lots of columns i'll try to write some of them:
Vis iD: (0x21 - 0x28)
VisDepth: 16
VisType: TrueColor/DirectColor
TransParent: 0
buffsize: 16
level: 0
renderType: rgba

Until this coulmne everything looks the same on both computers.

DB : 0/1
stereo: 0
R-sz: 5
G-sz: 6
B-sz: 5
a-sz: 0
aux-buf: 0
depth: 0/16
stencl: 0
acr: 16

on the extensions, GLX_ARB_multisample, is the only extension that the Geforce has but the Quadro doesn't. But I also don't see it in the sgi stations.

I hope i explained it to you more detailed this time.
thnx Ilan.

[bwkaz]

Are they both running in 16-bit color mode? Are you asking glXChooseVisual for a 24-bit mode maybe?

And I see in the manpage for glXChooseVisual that:

There is no direct filter for picking only visuals that support GLXPixmaps. GLXPixmaps are supported for visuals whose GLX_BUFFER_SIZE is one of the pixmap depths supported by the X server So I assume this condition holds? I don't know what pixmap depths X servers support, but it is (extremely unlikely, but) possible that 16-bit isn't one of them...

[ilan_gr]

I can see it now. On the computer with the GeForce3 Ti 200 and on the SGI stations I have some 24 color depth and some 16.
But on the Quadro4 system i only have only 16 color depth.
Maybe Thats why it doesn't work on this station.

But why i don't have 24 color depth, it is supposed to be more powerfull vga card than the other ones?

Do you have any alternate solution for printing into a picture file or printer in OpenGL?

thnx,
Ilan

[bwkaz]

Your XF86Config controls the color depth. Make the DefaultColorDepth (or DefaultDepth; use whichever you have) line be 24, and make sure there's a Display SubSection with a Depth of 24 and a set of modes listed there.

[ilan_gr]

I just changed the display settings to 24bit and it worked.

It is still strange because the station with the GeforceIII works in 16 bit color depth but can work with glXChooseVisual.

But this doesn't matter now!

Thank you very much :D