I have an Asus AMD Radeon 5870V2 with Ubuntu 11.04 and I cannot get a multisample framebuffer (8 samples per pixel) working with Catalyst 11.7 and 11.8 . I enable multisampling with glEnable(GL_MULTISAMPLE) and check the result with glGetIntegerv(GL_SAMPLES,&numSamples). numSamples = 8. This is correct.
Also forcing multisampling in the Catalyst control center don’t work. I can get a working multisample framebuffer with catalyst 11.6 with the same code. So I suspect a bug inside the version 11.7 and 11.8 of the driver. The only way I can do fullscreen anti-aliasing with those two latest Catalyst drivers is to draw the scene in a FBO with a multisample renderbuffer attached. Then blit the result to another FBO to resolve and use the texture on a fullscreen quad.
Does anybody that have an AMD Radeon on linux noticed the same problem?
I can post a cleaned version of my program upon request.
I would like a cleaned up version of your program but the fact that it used to work and doesn’t work with driver overrides is in itself a troubling factor. That doesn’t preclude breakage in your app that used to have no effect but it should be explored.
Here is a very small test program that always reproduce the problem with multisample framebuffer. With this small program, the triangle have smooth edge with Catalyst 11.6 but have jagged edge with Catalyst 11.7 and 11.8 . Also there is two screen shot.
The 4.1.10834.png image from Catalyst 11.6 show the correct behavior. The 4.1.11005.png image from Catalyst 11.8 show the “wrong” behavior.