VS/PS_NUM_REG is 6-bit on Adreno 200, and games aren't seen using the bit 7 to indicate that no GPRs are used. It's not clear why Freedreno configures it this way. Some texture fetch fields were deprecated or moved during the development of the Xenos, reflect that in the comments. Add definitions of the registers configuring the conversion of vertex positions to fixed-point. Although there isn't much that can be done with it when emulating using PC GPU APIs, there are some places in Xenia that wrongly (though sometimes deliberately, for results closer to the behavior of the host GPU) assume that the conversion works like in Direct3D 10+, however the Xenos supports only up to 4 subpixel bits rather than 8. The effects of this difference are largely negligible, though. Also add more detailed info about register references and differences from other ATI/AMD GPUs for potential future contributors.
67 KiB
67 KiB