The benefit to exposing this over the raw BP state is that adjustments Dolphin makes, such as LOD biases from arbitrary mipmap detection, will work properly.
This was added in 0b9a72a62d38481ff08f742b2318d07f29ff5dff but became irrelevant in 70f9fc4e7526fc9cfc008a43cd33229f62be99b6 as the check is now self-explanatory due to a rejiggering of the bitfields.
The compiler was loudly announcing each and every branch Tev was not checking in
a switch statement, but Tev has learned it's lesson and will produce that
warning no more.
Currently the logic for addressing the individual TexUnits is splattered all
across dolphin's codebase, this commit attempts to consolidate it all into a
single place and formalise it using our new TexUnitAddress struct.
This fixes various texture offsetting issues with negative texture coordinates (bringing the software renderer in line with the hardware renderers). It also handles the invalid wrap mode accurately (as was done for the hardware renderers in the previous commit). Lastly, it handles wrapping with non-power-of-2 texture sizes in a hardware-accurate way (which is somewhat broken looking, as games aren't supposed to use wrapping with non-power-of-2 sizes); this has not been done for the hardware renderers.
SPDX standardizes how source code conveys its copyright and licensing
information. See https://spdx.github.io/spdx-spec/1-rationale/ . SPDX
tags are adopted in many large projects, including things like the Linux
kernel.
Running the min/max operation on the upside down, quad-rounded pixel
coordinates before inverting them to the standard upper-left origin
produces wrong results. Therefore, we need to do the inversion before
rounding to pixel quads.
We also need to ensure the the CPU does not receive stale values
which have been updated by the GPU. Apparently the buffer here
is not coherent on NVIDIA drivers. Not sure if this is a driver
bug/spec violation or not, one would think that
glGetBufferSubData() would invalidate any caches as needed, but
this path is only used on NVIDIA anyway, so it's fine. A point
to note is that according to ARB_debug_report, it's moved from
video to host memory, which would explain why it needs the
cache invalidate.
