View Full Version : Problem with ARBMultisample (FSAA)

05-29-2004, 10:38 AM
Well I have been triing to get this for a while, and am having no luck.

I have ARBMultisampleing enabled, but I'm unable to disable it.

I should be able to do a glDisable(GL_MULTISAMPLE_ARB); but it is still antialiased after the call.

Any one have any idea how to disable it?

Thanks for any input.

05-29-2004, 02:40 PM
Let me guess, you are using an ATI card?
If yes, you are lost :-) On those cards Multisampling canīt be disabled at runtime. This problem is well known to ATI, but until now they didnīt fix it. It might be well possible, they wonīt ever fix it.

05-29-2004, 03:38 PM
On certain GPUs/drivers, it just doesn't work. You can't disable multisampling after the context has been created with a FSAA pixel format.

See for example bottom of http://developer.apple.com/qa/qa2001/qa1268.html

"Currently, ATI graphics hardware prior to the Radeon 9800 Pro and Radeon 9600 Pro do not support the enable flag for multi-sampling, leaving it enabled in all cases. It is recommended that client correctly set the enable flag for the context as needed but not expect glDisable to be respected for certain ATI hardware."

(tho, in my testing, that should read "prior to and including")

05-29-2004, 08:00 PM
Yeah using an ATI...Hmmm

Well is there any way to override a AA setting set in windows, so my GL will never be multisampled?

05-30-2004, 12:20 AM
Nope, the user has the final say on whether FSAA is applied. I would like to be able to overide multisampling to.