On all platforms, this would result in out of bounds accesses when getting the component sizes (which uses stuff from VertexLoader_Position.h/VertexLoader_TextCoord.h/VertexLoader_Normal.h). On platforms other than x64 and ARM64, this would also be out of bounds accesses when getting function pointers for the non-JIT vertex loader (in VertexLoader_Position.cpp etc.). Usually both of these would get data from other entries in the same multi-dimensional array, but the last few entries would be truly out of bounds. This does mean that an out of bounds function pointer can be called on platforms that don't have a JIT vertex loader, but it is limited to invalid component formats with values 5/6/7 due to the size of the bitfield the formats come from, so it seems unlikely that this could be exploited in practice.
This issue affects a few games; Def Jam: Fight for New York (https://bugs.dolphin-emu.org/issues/12719) and Fifa Street are known to be affected.
I have not done any hardware testing for this PR specifically, though I *think* I previously determined that at least a value of 5 behaves the same as float (4). That's what I implemented in any case. I did previously determine that both Def Jam: Fight for New York and Fifa Street use an invalid normal format, but don't actually have lighting enabled when that normal vector is used, so it doesn't change rendering in practice.
The color component format also has two invalid values, but VertexLoader_Color.h/.cpp do check for those invalid ones and return a default value instead of doing an out of bounds access.
Jimmie Johnson's Anything with an Engine is known to use texture coordinate 7 (and only texture coordinate 7) in some cases. There are a lot of possible edge-cases, so this test brute-forces all combinations with coordinates 0, 1, and 2.
This test fails with the non-JIT vertex loader due to an issue fixed in a later commit in this PR. (Note that the non-JIT vertex loader is only used on machines where no JIT is available or if COMPARE_VERTEXLOADERS is enabled in VertexLoaderBase.cpp.)
DataReader is generally jank - it has a start and end pointer, but the end pointer is generally not used, and all of the vertex loaders mostly bypassed it anyways.
Wrapper code (the vertex loaer test, as well as Fifo.cpp and OpcodeDecoding.cpp) still uses it, as does the software vertex loader (which is not a subclass of VertexLoader). These can probably be eliminated later.
This currently fails for direct with NormalIndex3 enabled (see https://bugs.dolphin-emu.org/issues/12952). The goal of this test is to be able to confidently say that that bug has been fixed.
We have one that does a similar thing, but only to measure speed and uses indices. This one verifies accuracy (and uses the largest possible input size by using direct components).
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.
[conv.fpint]/1:
> A prvalue of a floating-point type can be converted to a prvalue of
> an integer type. The conversion truncates; that is, the fractional
> part is discarded. The behavior is undefined if the truncated value
> cannot be represented in the destination type.
Additionally, VCacheEnhance has been added to UVAT_group1. According to YAGCD, this field is always 1.
TVtxDesc also now has separate low and high fields whose hex values correspond with the proper registers, instead of having one 33-bit value. This change was made in a way that should be backwards-compatible.
Keeps all of the floating-point utility functions in their own file to
keep them all together. This also provides a place for other
general-purpose floating-point functions to be added in the future,
which will be necessary when improving the flag-setting within the
interpreter.
Fixes warning:
```
../Source/UnitTests/VideoCommon/VertexLoaderTest.cpp:222:15: error: variable 'f' may be uninitialized when used here [-Werror,-Wconditional-uninitialized]
ExpectOut(f * scale);
^
../Source/UnitTests/VideoCommon/VertexLoaderTest.cpp:198:12: note: initialize the variable 'f' to silence this warning
float f, g;
^
= 0.0
../Source/UnitTests/VideoCommon/VertexLoaderTest.cpp:223:15: error: variable 'g' may be uninitialized when used here [-Werror,-Wconditional-uninitialized]
ExpectOut(g * scale);
^
../Source/UnitTests/VideoCommon/VertexLoaderTest.cpp:198:15: note: initialize the variable 'g' to silence this warning
float f, g;
^
= 0.0
```
They are used to remove the flush amounts, but as we don't
flush anymore on vertex loader changes (only on native
vertex format right now), this optimization is now unneeded.
This will allow us to hard code the frac factors within the
vertex loaders.
videoBuffer -> s_video_buffer
size -> s_video_buffer_write_ptr
g_pVideoData -> g_video_buffer_read_ptr (impl moved to Fifo.cpp)
This eradicates the wonderful use of 'size' as a global name, and makes
it clear that s_video_buffer_write_ptr and g_video_buffer_read_ptr are
the two ends of the FIFO buffer s_video_buffer.
Oh, and remove a useless namespace {}.
Tilka