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-   -   Quadro FX 540 and glReadPixels... (http://www.nvnews.net/vbulletin/showthread.php?t=63279)

kaloskagatos 01-13-06 10:20 AM

Quadro FX 540 and glReadPixels...
Hello :) ,

I work on a program which runs on different platforms (HP, SUN, Linux, IRIX). I use it though an XServer emulator (Exceed3D) from a Windows2000 PC.

All worked fine untill today when I used a Windows PC with Exceed3D and a Quadro FX 540. Now the glReadPixels function returns strange values such as shown by the following code:


glReadBuffer( GL_FRONT );
glReadPixels ( xmouse-1 , ymouse-1, 3, 3, GL_DEPTH_COMPONENT, GL_FLOAT, z_picking );

whitch return on a well working station :


z_picking = (0.6561477, 0.6561477, 0.6561477, 0.6561477, 0.6561399, 0.6561399, 0.6561399, 0.6561399, 0.6561399)

and on the nvidia PC :


z_picking = (-1.222404e+37, -1.222404e+37, -1.222404e+37, -1.222404e+37, -5.576056e+27, -5.576056e+27, -1.222404e+37, -5.576056e+27, -5.576056e+27)

The consequence is that I can't locate a point in my openGl scene using the gluUnProject function, and I musn't change it...

What am I doing wrong, or is there a problem with the driver? Thanks a lot for the time you'll spend answering me, and forgive my poor english ;)



kaloskagatos 01-14-06 09:11 AM

Re: Quadro FX 540 and glReadPixels...
Up (nana2)

marc 01-14-06 09:32 AM

Re: Quadro FX 540 and glReadPixels...
The call looks ok, but the result suggests that the size of 'GL_FLOAT' is incorrectly
set/interpreted somewhere along the line, because the numbers look like 32-bit floats in 64-bit double spaces...
I normally only do GLReadPixels with GL_UNSIGNED_BYTE as type (which has
kept me out of trouble so far)

kaloskagatos 01-16-06 04:13 AM

Re: Quadro FX 540 and glReadPixels...
Hi, you should be right but I've found it could be a bug from the driver or the openglLib...



kaloskagatos 01-16-06 04:32 AM

Re: Quadro FX 540 and glReadPixels...
I'm surprised this problem still exists... Does any one have a solution?

Marc, I've tried different combinaisons of type, nothing changes...

kaloskagatos 01-16-06 09:23 AM

Re: Quadro FX 540 and glReadPixels...
Any idea? :(

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