With alpha to coverage, alpha to one, and the depth test enabled, the depth buffer unmasked, and a depth test of less than or equal to, would you expect a 50 % alpha polygon rendered to a clear (color, depth, and stencil) frame buffer at z = x to cause the clear color to occlude a fully opaque polygon rendered at depth z = x + 1, where x and x + 1 are resolvable depth values?
It would appear that it does with current ATI drivers, but not with current nVidia ones. I believe some previous ATI drivers (I can’t remember the exact versions) did not behave this way.
Which behavior is correct? Thanks.