Prior to 7854bd7109, this was used by the debugger for the OpenGL and D3D9 plugins to control logging (via PRIM_LOG and INFO_LOG/DEBUG_LOG in VideoCommon code; PRIM_LOG was changed in 77215fd27c), and also framedumping (removed in 64927a2f81 and 2d8515c0cf), shader dumping (removed in 2d8515c0cf and this commit), and texture dumping (removed in 54aeec7a8f). Apart from shader dumping, all of these features have modern alternatives, and shader source code can be seen in RenderDoc if "Enable API Validation Layers" is checked (which also enables source attachment), so there's no point in keeping this around.
This normalization was added in 02ac5e95c8, and changed to use floats in 4bf031c064. The conversion to floats means that sometimes there is insufficient precision for the normalization process, which results in values of NaN or infinity. Performing the whole process with doubles prevents that, but games also sometimes set the values to NaN or infinity directly (possibly accidentally due to the values not being initialized due to them not being used in the current configuration?).
The version of Mesa currently in use on FifoCI (20.3.5) has issues with NaN. Although this bug has been fixed (https://gitlab.freedesktop.org/mesa/mesa/-/commit/b3f3287eac066eae16dce0e47aad3229dcff8257 in 21.2.0), FifoCI is stuck with the older version.
This change may or may not be incorrect, but it should result in the same behavior as already present in Dolphin, while working around the Mesa bug.
https://bugs.dolphin-emu.org/issues/12977 indicates that this happens on startup of Spider-Man 2, even in single-core. I don't have the game, so I can't directly determine why this is happening, but presumably real hardware does not hang in this case, so we can make it less obtrusive.
Looks like a copy-paste gone wrong. The compute shaders for the other
formats use a group size of 8 * 8, whereas the CMPR compute shader
is supposed to use a flattened 64 * 1 as I understand it.
Scott MansellandGitHub
Pokechu22
Shawn Hoffman
JosJuiceandGitHub
Admiral H. CurtissandGitHub
TellowKrinkle
Joon Park
JMC47andGitHub