This was because the shader uniforms between the pixel and vertex shaders
were willingly left different, to avoid filling the vertex shader with unnecessary
params. Turns out all backends are fine with this except OGL.
The new behaviour is now much more consistent and well explained,
the "default" shaders are the ones that always run, and the non default
ones are the user selected ones (if any).
In std::string, you can store strings using any encoding, but in Dolphin
we have decided to use UTF-8. The problem is that if you convert between
std::string and std::filesystem::path using the built-in methods, the
standard library will make up its own assumption of what encoding you're
using in the std::string. On most OSes this is UTF-8, but on Windows
it's whatever the user's code page is.
What I believe is the C++ standard authors' intended solution to this is
to use std::u8string instead of std::string, but that's a big hassle to
move over to, because there's no convenient way to convert between
std::string and std::u8string. Instead, in Dolphin, we have added helper
functions that convert between std::string and std::filesystem::path in
the manner we want. You *always* have to use these when converting
between std::string and std::filesystem::path, otherwise we get these
kinds of encoding problems that we've been having with custom textures.
Fixes https://bugs.dolphin-emu.org/issues/13328.
To further increase the accuracy of the post process phase, I've added (scRGB) HDR support, which is necessary
to fully display the PAL and NTSC-J color spaces, and also to improve the quality of post process texture samplings and
do them in linear space instead of gamma space (which is very important when playing at low resolutions).
For SDR, the quality is also slightly increased, at least if any post process runs, as the buffer is now
R10G10B10A2 (on Vulkan, DX11 and DX12) if supported; previously it was R8G8B8A8 but the alpha bits were wasted.
Gamma correction is arguably the most important thing as Dolphin on Windows outputted in "sRGB" (implicitly)
as that's what Windows expects by default, though sRGB gamma is very different from the gamma commonly used
by video standards dating to the pre HDR era (roughly gamma 2.35).
Additionally, the addition of HDR support (which is pretty straight forward and minimal), added support for
our own custom AutoHDR shaders, which would allow us to achieve decent looking HDR in Dolphin games without
having to use SpecialK or Windows 11 AutoHDR. Both of which don't necessarily play nice with older games
with strongly different and simpler lighting. HDR should also be supported in Linux.
Development of my own AutoHDR shader is almost complete and will come next.
This has been carefully tested and there should be no regression in any of the different features that Dolphin
offers, like multisampling, stereo rendering, other post processes, etc etc.
Fixes: https://bugs.dolphin-emu.org/issues/8941
Co-authored-by: EndlesslyFlowering <EndlesslyFlowering@protonmail.com>
Co-authored-by: Dogway <lin_ares@hotmail.com>
