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View Full Version : No 32 bit's Z-Buffer in linux



BGM
03-28-2002, 02:45 AM
I have a Geforce2 mx 400 with 64 mb ram.

If I try to use a 32 bit Z-Buffer under linux
it doesn't work, however under windows a 32 bit
Z-Buffer is no problem. My drivers are up to date
in windows and in linux, so why doesn't it work ?

PS the error I get : Couldn't find matching GLX visual

03-29-2002, 01:16 AM
I think NVidia cards gives you a depth buffer size depending on the color depth. A screen in 16 bit color depth gives you a 16 bit depth buffer. If 24 bit colors is used will you get an 24 bit Z-buffer combined with a 8 bit stencil buffer. This is the same under both Windows and linux. You can see the available visuals with the glxinfo command.

The man page for glXChooseVisual says:
" glXChooseVisual returns a pointer to an XVisualInfo structure describing the visual that best meets a minimum specification. The boolean GLX attributes of the visual that is returned will match the specified values, and the integer GLX attributes will meet or exceed the specified minimum values."
This means that if you specify a Z-buffer size between 1-24 will you get the 24+8 combination. If you ask for a 32 bit depth buffer will the function fail and return NULL.