forked from dolphin-emu/dolphin
The obvious question here is, why does it matter if we round or truncate? The key is that GC/Wii does fixed-point interpolation, where PC GPUs do floating-point interpolation. Discarding fractional bits makes the conversion from floating-point to fixed point give more consistent results. I'm not confident this is really the right fix, or that my explanation is completely correct; ideally, we don't want to depend on floating-point interpolation at all.