**What are push constants?**
Push constants is a way to quickly provide a small amount of uniform data to shaders.
It should be much quicker than UBOs but a huge limitation is the size of data - spec
requires 128 bytes to be available for a push constant range.
**What are the challenges with push constants?**
The challenge with push constants is that the limited available size. According to
the Vulkan spec each platform should at least have 128 bytes reserved for push
constants. Current Mesa/AMD drivers supports 256 bytes, but Mesa/Intel is only 128
bytes.
**What is our solution?**
Some shaders of Blender uses more than these boundaries. When more data is needed
push constants will not be used, but the shader will be patched to use an uniform
buffer instead. This mechanism will be part of the Vulkan backend and shader
developers should not see any difference on API level.
**Known limitations**
Current state of the vulkan backend does not track resources that are in the
command queue. This patch includes some test cases that identified this issue as
well. See #104771.
Pull Request #104880
Previously, UBO bind locations were linearly incremented and
relied on the correct uniform location being queried. This fix
is a future requirement for EEVEE next, however, pulling forward
due to Issue #105280 highlighting a possible flaw with expected
uniform locations.
Authored by Apple: Michael Parkin-White
Ref #96261
Pull Request #105311
With the goal of clearly differentiating between arrays and single
elements, improving consistency across Blender, and using wording
that's easier to read and say, change variable names for Mesh edges
and polygons/faces.
Common renames are the following, with some extra prefixes, etc.
- `mpoly` -> `polys`
- `mpoly`/`mp`/`p` -> `poly`
- `medge` -> `edges`
- `med`/`ed`/`e` -> `edge`
`MLoop` variables aren't affected because they will be replaced
when they're split up into to arrays in #104424.
This pull request adds a new tipe of resource handles (thin handles).
These are intended for cases where a resource buffer with more than one
entry for each object is needed (for example, one entry per material
slot).
While it's already possible to have multiple regular handles for the
same object, they have a non-trivial overhead in terms of uploaded
data (matrix, bounds, object info) and computation (visibility
culling).
Thin handles store an indirection buffer pointing to their "parent"
regular handle, therefore multiple thin handles can share the same
per-object data and visibility culling computation.
Thin handles can only be used in their own Pass type (PassMainThin),
so passes that don't need them don't have to pay the overhead.
This pull request also includes the update of the Workbench Next
pre-pass to use PassMainThin, which is the main reason for the
implementation of this feature.
The main change from the previous PR is that the thin handles are now
stored directly in the main resource_id_buf, to avoid wasting an extra
bind slot.
Pull Request #105261
This was backported from tmp-vulkan. When disabling the fence check
in ghost it is able to start blender. It will show a black screen
so not usable for users.
Due to an error in GPU module we fixed the memory size in the
Vulkan backend. Last week the error has been fixed in the GPU module
so we can remove the temp fixes in the Vulkan backend.
Pull Request #105244
Similar to recent issues with gl_shader_interface,
ShaderInput lists need to be sorted to ensure correct
and efficient uniform lookup by name.
Authored by Apple: Michael Parkin-White
Ref #96261
Pull Request #105239
GPencil 3D stroke rendering uses a geometry shader.
This is unsupported by the Metal backend, so implement
fix for this failing compilation by shifting geometry shader
logic into the Vertex shader for Metal backend.
Authored by Apple: Michael Parkin-White
Ref #96261
Pull Request #105143
Metal LineLoop emulation path does not correctly apply
when using SSBO vertex fetch mode alongside 3D line
rendering.
Patch moves line emulation above SSBO
vertex fetch setup to ensure the correct emulation
parameters are passed to the shader.
Authored by Apple: Michael Parkin-White
Ref #96261
Pull Request #105142
Resolves issue with nearest filtering on UI Icons. Note that as
Metal does not support LOD bias as a parameter on a sampler
object, the original code has been modified to perform LOD
biasing at the shader level.
As GPU_SAMPLER_ICON is not widely used, it is more
efficient to apply directly to the affected shaders, rather
than workaround passing in the sampler LOD bias as a
separate value e.g. uniform or push constant.
Original PR feedback addressed to also refactor ICON
shaders to use consistent style for single and multi
Icon rendering.
Authored by Apple: Michael Parkin-White
Ref #96261
Pull Request #105145
This remove default casses from the `switch` statements to catch where
the missing cases are.
Uncomment unimplemented cases for the sake of completeness. Improving the
overall API.
This make the format conversion lists exhaustive and documented.
This replace `validate_data_format_mtl` by the common version as they
don't differ at all now.
For every other texture types this is expected to be implicitly
`GPU_DATA_FLOAT`. There is only one case where this is not the case.
I believe this was previously needed because the data type was
conditionning the texture creation. This is not the case anymore.
Resolving builtin uniforms and uniform blocks when creating
shader interface. This maps builtin uniforms to uniforms
defined by the shader. Works the same as the OpenGL
builtin uniforms.
Pull Request #105128
When using ShaderCreateInfo with builtin uniform(blocks) there are
cases where the current implementation could not find an existing
block. The reason is that it uses name matching and name matching
requires that the shader inputs are sorted based on the name hash.
This change fixes this by first for the sorting of the shader
inputs before resolving the builtins.
Pull Request #105127
Cycles fallback display shader previously did not use viewport.
This would crash or cause the display not to show when using
GPU backends other than OpenGL, if another display shader
was unavailable.
Now use ShaderCreateInfo for Cycles fallback display.
Authored by Apple: Michael Parkin-White
Ref #96261
Pull Request #104987
This patch will give access to the physical device limits
of the device associated with the context. In vulkan each
device has different limits and the application is
responsible to match these limits as the vulkan driver
just ignores calls that don't match these limits.
Those limits are GPUBackend specific and therefore are not
added to GPU_capabilities.
Pull Request #105125
The stoke shader of grease pencil uses a geometry shader stage. Apple
devices don't support shaders with geometry shader stage. In the
OpenGL driver there was a pass-through implemented so it didn't fail.
When using the metal backend this needs to be solved more explicitly.
This change patches the grease pencil shader to support both the
backends supporting a geometry stage and those without.
Fixes#105059
Pull Request #105116
Erroneous cache warming case where the generated material is
identical to default material and cached shader is re-used,
resulting in case where the parent shader is identical to the
source.
Authored by Apple: Michael Parkin-White
Ref #96261
Descriptor set locations are now determined in the
VKShaderInterface. Issues with the previous solution:
- Due to legacy code in GPU module the locations/bindings
must be the same. Using one for something else might
result in undesired lookups, incorrect resource
bindings.
- Images/Textures reuses the same namespace, that didn't
work as expected when looking up the resources via
its binding.
This refactoring is required for adding support for
push constants.
Pull Request #105073
