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4b5c7e3721
For temporary registers, SM1-SM3 integer types are internally
represented as floating point, so, in order to perform a cast
from ints to floats we need a mere MOV.
For constant integer registers "iN" there is no operation for casting
from a floating point register to them. For address registers "aN", and
the loop counting register "aL", vertex shaders have the "mova" operation
but we haven't used these registers in any way yet.
We probably would want to introduce these as synthetic variables
allocated in a special register set. In that case we have to remember to
use MOVA instead of MOV in the store operations, but they shouldn't be src
or dst of CAST operations.
Regarding constant integer registers, in some shaders, constants are
expected to be received formatted as an integer, such as:
int m;
float4 main() : sv_target
{
float4 res = {0, 0, 0, 0};
for (int k = 0; k < m; ++k)
res += k;
return res;
}
which compiles as:
// Registers:
//
// Name Reg Size
// ------------ ----- ----
// m i0 1
//
ps_3_0
def c0, 0, 1, 0, 0
mov r0, c0.x
mov r1.x, c0.x
rep i0
add r0, r0, r1.x
add r1.x, r1.x, c0.y
endrep
mov oC0, r0
but this only happens if the integer constant is used directly in an
instruction that needs it, and as I said there is no instruction that
allows converting them to a float representation.
Notice how a more complex shader, that performs operations with this
integer variable "m":
int m;
float4 main() : sv_target
{
float4 res = {0, 0, 0, 0};
for (int k = 0; k < m * m; ++k)
res += k;
return res;
}
gives the following output:
// Registers:
//
// Name Reg Size
// ------------ ----- ----
// m c0 1
//
ps_3_0
def c1, 0, 0, 1, 0
defi i0, 255, 0, 0, 0
mul r0.x, c0.x, c0.x
mov r1, c1.y
mov r0.y, c1.y
rep i0
mov r0.z, r0.x
break_ge r0.y, r0.z
add r1, r0.y, r1
add r0.y, r0.y, c1.z
endrep
mov oC0, r1
Meaning that the uniform "m" is just stored as a floating point in
"c0", the constant integer register "i0" is just set to 255 (hoping
it is a high enough value) using "defi", and the "break_ge"
involving c0 is used to break from the loop.
We could potentially use this approach to implement loops from SM3
without expecting the variables being received as constant integer
registers.
According to the D3D documentation, for SM1-SM3 constant integer
registers are only used by the 'loop' and 'rep' instructions.
=============================
The vkd3d 3D Graphics Library
=============================
Vkd3d is a 3D graphics library built on top of Vulkan. It has an API very
similar, but not identical, to Direct3D 12.
==============
Building vkd3d
==============
Vkd3d depends on SPIRV-Headers and Vulkan-Headers (>= 1.3.228).
Vkd3d generates some of its headers from IDL files. If you are using the
release tarballs, then these headers are pre-generated and are included. If
you are building from git, then they will be generated at build-time using
widl. By default, vkd3d will use the widl found in `PATH'. If widl is not
available or is not recent (>= 3.21), then you can build Wine with `make
tools/widl/widl' to avoid building all of Wine. You can then point vkd3d's
configure at that widl binary with `WIDL="/path/to/widl"'.
For release builds, you may want to define NDEBUG. If you do not need debug log
messages, you may also consider VKD3D_NO_TRACE_MESSAGES and
VKD3D_NO_DEBUG_MESSAGES. For example, you can pass `CPPFLAGS="-DNDEBUG
-DVKD3D_NO_TRACE_MESSAGES"' to configure.
===========
Using vkd3d
===========
Vkd3d can be used by projects that target Direct3D 12 as a drop-in replacement
at build-time with some modest source modifications.
If vkd3d is available when building Wine, then Wine will use it to support
Direct3D 12 applications.
=====================
Environment variables
=====================
Most of the environment variables used by vkd3d are for debugging purposes. The
environment variables are not considered a part of API and might be changed or
removed in the future versions of vkd3d.
Some of debug variables are lists of elements. Elements must be separated by
commas or semicolons.
* NO_COLOR - this is an alias of NO_COLOUR.
* NO_COLOUR - when set, vkd3d-compiler and vkd3d-dxbc will default to
monochrome output, even when the output supports colour.
* VKD3D_CONFIG - a list of options that change the behavior of libvkd3d.
* virtual_heaps - Create descriptors for each D3D12 root signature
descriptor range instead of entire descriptor heaps. Useful when push
constant or bound descriptor limits are exceeded.
* vk_debug - enables Vulkan debug extensions.
* VKD3D_DEBUG - controls the debug level for log messages produced by
libvkd3d. Accepts the following values: none, err, fixme, warn, trace.
* VKD3D_VULKAN_DEVICE - a zero-based device index. Use to force the selected
Vulkan device.
* VKD3D_DISABLE_EXTENSIONS - a list of Vulkan extensions that libvkd3d should
not use even if available.
* VKD3D_SHADER_CONFIG - a list of options that change the behavior of
libvkd3d-shader.
* force_validation - Enable (additional) validation of libvkd3d-shader's
internal representation of shaders.
* VKD3D_SHADER_DEBUG - controls the debug level for log messages produced by
libvkd3d-shader. See VKD3D_DEBUG for accepted values.
* VKD3D_SHADER_DUMP_PATH - path where shader bytecode is dumped.
* VKD3D_TEST_DEBUG - enables additional debug messages in tests. Set to 0, 1
or 2.
* VKD3D_TEST_FILTER - a filter string. Only the tests whose names matches the
filter string will be run, e.g. VKD3D_TEST_FILTER=clear_render_target.
Useful for debugging or developing new tests.
* VKD3D_TEST_PLATFORM - can be set to "wine", "windows" or "other". The test
platform controls the behavior of todo(), todo_if(), bug_if() and broken()
conditions in tests.
* VKD3D_TEST_BUG - set to 0 to disable bug_if() conditions in tests.
If the configuration defines 'DXCOMPILER_LIBS=-L/path/to/dxcompiler', Shader
Runner attempts to load libdxcompiler.so or dxcompiler.dll to compile test
shaders in Shader Model 6. LD_LIBRARY_PATH (linux), WINEPATH (wine) or PATH
(native windows) should include the location of dxcompiler if SM 6 shader
tests are desired. If dxcompiler is not found, Shader Runner will compile the
test shaders only in earlier shader models. The DXC source does not contain
code for adding DXBC checksums, so the official release should be installed
from:
https://github.com/microsoft/DirectXShaderCompiler/releases
================
Developing vkd3d
================
Development of vkd3d happens on the Wine GitLab instance
(https://gitlab.winehq.org/wine/vkd3d/). Contributors are encouraged
to submit their patches using the merge request tool.
Each merge request is automatically tested with the GitLab CI
system. See gitlab/README in the Git tree for more details.