Now, a note about the actual issue. Destination alpha tests can be used on the GS as one of the workarounds for a lack of stencils. If you use a destination alpha test and leave alpha writing on, the GS will only write each pixel until you write an alpha value which would fail the test. This works to a point in gsdx without further hacking, but that point is when within a single batch of primitives the same pixels are written multiple times and the destination alpha test is expected to update. I did experimentally make a tight loop updating the stencil with a draw then drawing for one primitive at a time, but it was prohibitively slow (over 80% fps loss, you really don't want to know).
Destination alpha testing cannot be directly implemented in D3D9 or D3D10, but (probably) can in D3D11 (with a speed hit for sure, but I doubt it'll be 80%). I'll be getting a new graphics card and looking into that.
And before some idiot says it, the answer is no. OpenGL does not help.
git-svn-id: http://pcsx2.googlecode.com/svn/trunk@5346 96395faa-99c1-11dd-bbfe-3dabce05a288
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