This adds basic unrolling support for 2 syntax:
- `[[gpu::unroll]]` which does full loop unrolling
- `[[gpu::unroll(x)]]` which unrolls `x` iteration
Nesting is supported.
This change is motivated by the added cost in compilation
and execution time that some loops have even if they have
compile time defined iteration counts.
The syntax is inspired by `GL_EXT_control_flow_attributes`.
However, we might want to have our own prefix to show it is
a blender specific feature and that it differs from the standard.
I propose `[[gpu::unroll]]`.
In the future, we could extend this to support more directives that
can be expanded to backend specific extension / syntax. This would
avoid readability issue an error prone copy paste of large amount
of preprocessor directives.
Currently, given that GL's GLSL flavor doesn't support
any of these attributes, the preprocessor does some copy-pasting
that does the unrolling at the source level. Note that the added
`#line` allow for correct error logging.
For the `[[gpu::unroll]]` syntax, the `for` declaration
needs to follow a specific syntax to deduce the number
of loop iteration.
This variant removes the continue condition between iteration,
so all iterations are evaluated. This could be modified
using a special keyword.
For the `[[gpu::unroll(n)]]` syntax, the usercode needs
to make sure that `n` is large enough to cover all iterations
as the loop is completely removed.
We could add shader `assert` to make sure that there is
never a remaining iteration.
This behavior is usually different from what you see in other
implementation as we do not keep a loop at all. Usually, compilers
still keep the loop if it is not unrolled fully. But given we don't
have IR, this is the best we can do.
`break` and `continue` statement are forbidden at the unrolled loop
scope level. Nested loop and switch can contain these keywords.
This is accounted for by checks in the pre-processor.
Only `for` loops are supported for now. There are no real
incentive to add support for `while` given how rare it is
in the shader codebase.
Rel #137446
Pull Request: https://projects.blender.org/blender/blender/pulls/137444
This avoid having to guards functions that are
only available in fragment shader stage.
Calling the function inside another stage is still
invalid and will yield a compile error on Metal.
The vulkan and opengl glsl patch need to be modified
per stage to allow the fragment specific function
to be defined.
This is not yet widely used, but a good example is
the change in `film_display_depth_amend`.
Rel #137261
Pull Request: https://projects.blender.org/blender/blender/pulls/138280
This makes no sense to have in the draw namespace.
Also take the opportunity for making the coordinates
a float2 and rename them to something more descriptive.
Do this only when applicable.
This allow better compile time checking in Shader C++ compilation.
Moreover, this allows to have `constexpr` in shared code between
C++ and GLSL.
After investigation the `const` keyword in GLSL has the same
semantic than C/C++.
Rel #137333 and #137446
Pull Request: https://projects.blender.org/blender/blender/pulls/137497
This unify the C++ and GLSL codebase style.
The GLSL types are still in the backend compatibility
layers to support python shaders. However, the C++
shader compilation layer doesn't have them to enforce
correct type usage.
Note that this is going to break pretty much all PRs
in flight that targets shader code.
Rel #137261
Pull Request: https://projects.blender.org/blender/blender/pulls/137369
They are actually already some literals with the `f` suffix
that are in our shader codebase and we never had problem in
the past 5 years (or even 8 years).
So I think it is safe to do and improves convergence of codestyles.
Pull Request: https://projects.blender.org/blender/blender/pulls/137352
Workbench shaders uses one fragment shaders, but uses different
resources based on the step of the effect. This failed in vulkan as all
defined resources should be found. This PR separates the steps in its
own fragment shader and adds sampler binding per step.
- Removed the max coc input texture as it wasn't used.
- Removed the background texture as it wasn't used.
- Renumbered the resources.
Pull Request: https://projects.blender.org/blender/blender/pulls/131606
Continuation of #131332.
Including built-in headers in VS2019 ends up including `corecrt_math.h`
as a side effect, which has many functions that overlap in name with
our stubs.
This puts the conflicting functions inside its own namespace (`glsl`)
and declares macros for them.
(Note this has the side effect of not allowing us to use those as
variable names)
This also removes the `<cassert>` and `<cstdio>` includes.
Pull Request: https://projects.blender.org/blender/blender/pulls/131386
Move most of the string preprocessing used for MSL
compatibility to `glsl_preprocess`.
Enforce some changes like matrix constructor and
array constructor to the GLSL codebase. This is
for C++ compatibility.
Additionally reduce the amount of code duplication
inside the compatibility code.
Pull Request: https://projects.blender.org/blender/blender/pulls/128634
This changes the include directive to use the standard C preprocessor
`#include` directive.
The regex to applied to all glsl sources is:
`pragma BLENDER_REQUIRE\((\w+\.glsl)\)`
`include "$1"`
This allow C++ linter to parse the code and allow easier codebase
traversal.
However there is a small catch. While it does work like a standard
include directive when the code is treated as C++, it doesn't when
compiled by our shader backends. In this case, we still use our
dependency concatenation approach instead of file injection.
This means that included files will always be prepended when compiled
to GLSL and a file cannot be appended more than once.
This is why all GLSL lib file should have the `#pragma once` directive
and always be included at the start of the file.
These requirements are actually already enforced by our code-style
in practice.
On the implementation, the source needed to be mutated to comment
the `#pragma once` and `#include`. This is needed to avoid GLSL
compiler error out as this is an extension that not all vendor
supports.
Rel #127983
Pull Request: https://projects.blender.org/blender/blender/pulls/128076
Workbench doesn't fill all texture slots. In OpenGL it should match what
the shader is using, where some texture slots that have been defined can
be optimized away when not used. The Vulkan backend however uses all the
resources that has been defined in the shader create info.
When using a texture shader in workbench the shader would raise a
validation warning as there are slots defined that are never uploaded.
This PR fixes this by always set dummy textures in those slots.
Pull Request: https://projects.blender.org/blender/blender/pulls/127064
This PR introduces the concept of primitive expansion draws.
This allows to create a drawcall that will generate N amount of new
primitive for an original primitive in a `gpu::Batch`. The intent is to
phase out the use of geometry shader for this purpose.
This adds a new `Frequency::GEOMETRY` only available for SSBOs.
The resources using this will be fed the current `gpu::Batch` VBOs
using name matching.
A dedicated slot is reserved for the index buffer, which has its own
internal lib to decode the index buffer content.
A new attribute lib is added to ease the loading of unaligned attribute.
This should be revisited and made obsolete once more refactor
lands.
It is similar to the Metal backend SSBO vertex fetch path but it is
defined on a different level. The main difference is that this PR is
backend independant and modify the draw module instead of the GPU
module. However, it doesn't cover all possible attribute conversion
cases. This will only be added if needed.
This system is less automatic than the Metal backend one and needs
more care to make sure the data matches what the shader expects.
The Metal system will be removed once all its usage have been
converted.
This PR only shows example usage for workbench shadows. Cleanup PRs
will follow this one.
Rel #105221
Pull Request: https://projects.blender.org/blender/blender/pulls/125782
