Presentation context always has GL_DRAW_FRAMEBUFFER_BINDING as zero.
There is no need to bind the default framebuffer constantly.
According to Nsight this was using ~0.7ms per frame and it broke
renderdoc captures.
This is a reversed look up table extracted from
https://gist.github.com/rygorous/2203834#file-gistfile1-cpp-L41-L62
that is used in
04d4e9e587/source/maxwell/tsc_generate.cpp (L38)
Games usually bind 0xFD expecting a float texture border of 1.0f.
The conversion previous to this commit was multiplying the uint8 sRGB
texture border color by 255. This is close to 1.0f but when that
difference matters, some graphical glitches appear.
This look up table is manually changed in the edges, clamping towards
0.0f and 1.0f.
While we are at it, move this logic to its own translation unit.
Credits go to gdkchan and Ryujinx. The pull request used for this can
be found here: https://github.com/Ryujinx/Ryujinx/pull/1082
yuzu was already using the header for interpolation, but it was missing
the FragCoord.w multiplication described in the linked pull request.
This commit finally removes the FragCoord.w == 1.0f hack from the shader
decompiler.
While we are at it, this commit renames some enumerations to match
Nvidia's documentation (linked below) and fixes component declaration
order in the shader program header (z and w were swapped).
https://github.com/NVIDIA/open-gpu-doc/blob/master/Shader-Program-Header/Shader-Program-Header.html
Fernando Sahmkow