ATI Talks About AquaMark3 Issues

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ATI talks about rendering issues in AquaMark3 discovered by Tom's Hardware Guide at RivaStation. It seems that there's a small issue with the alpha-blender of the R300 and its followers. When or if it has been fixed with the 7.96 CoD hotfix is not known. It took much longer than I anticipated, but we reached to a conclusion on the AM3 "explosion" issue. The initial suspicions about our alpha blenders turned out to be true. To prove this we had to run the test scene on a future HW emulator - which took all this effort. To summarize at a high level - we have single-bit differences when alpha blending compared to ref-rast image. When accumulating several layers of alpha blend objects, some pixels may end up looking darker on R300 family than refrast. We are rendering all the layers and the deviation we have in rendering each pixel is within an acceptable tolerance level from refrast - as evidenced by the fact that we pass all the WHQL DCT tests that compare images rendered on R300 v/s refrast.