I did some experimentation and it seems to me that the
WGL_SAMPLE_BUFFERS_ARB attribute does only work for pixel format descriptors
if in conjunction with attribute WGL_DRAW_TO_WINDOW_ARB and not
WGL_DRAW_TO_PBUFFER_ARB!!
Does anybody have experience with antialiased PBuffers on Radeon cards?
One possible implementation of antialiasing puts more than one sample into the frame buffer, and then reads more than one sample out into the DAC, and the actual anti-aliasing blend happens on scan conversion.
If that were the implementation, then I could see very easily how it wouldn’t work in a pbuffer – there’s no DAC to blend the samples for you.