Add-ons can still use the legacy API that only works on OpenGL. Vulkan
however was crashing as there is no shader create info available.
Adding a pre-check when finalizing shaders on availability of shader
create info.
Pull Request: https://projects.blender.org/blender/blender/pulls/130660
Dynamic rendering is a Vulkan 1.3 feature. Most platforms have support
for them, but there are several legacy platforms that don't support dynamic
rendering or have driver bugs that don't allow us to use it.
This change will make dynamic rendering optional allowing legacy
platforms to use Vulkan.
**Limitations**
`GPU_LOADACTION_CLEAR` is implemented as clear attachments.
Render passes do support load clear, but adding support to it would
add complexity as it required multiple pipeline variations to support
suspend/resume rendering. It isn't clear when which variation should
be used what lead to compiling to many pipelines and branches in the
codebase. Using clear attachments doesn't require the complexity
for what is expected to be only used by platforms not supported by
the GPU vendors.
Subpass inputs and dual source blending are not supported as
Subpass inputs can alter the exact binding location of attachments.
Fixing this would add code complexity that is not used.
Ref: #129063
**Current state**

Pull Request: https://projects.blender.org/blender/blender/pulls/129062
In multiple parts (framebuffer and shader) the render areas/viewport could be
copied in an array of 16 structs, when only one is needed. This PR will use builder
patters so we don't over-allocate. Would spend less CPU cycles when constructing
render info, render passes/framebuffers, shaders.
Cleanup was part of !129062
Pull Request: https://projects.blender.org/blender/blender/pulls/130515
Shader interface used shader create info bind types to communicate bind
types to descriptor sets. However Vulkan supports more bind types than
Blender exposes in its API. Current implementation resulted that next to
the bind type the actual resource was queried to find out what needed to
be done.
This PR makes it more clear to convert the shader create info bind type
to `VKBindType` that contains the vulkan bind types we support.
Pull Request: https://projects.blender.org/blender/blender/pulls/130509
OpenGL & Vulkan has workarounds when gl_Layer/gl_ViewportIndex isn't
supported. In this case a geometry shader will is generated. This
geometry shader doesn't follow the GLSL standard and doesn't work on
some platforms. This has not been an issue as the platforms that
don't support gl_Layer/gl_ViewportIndex don't show the issue.
According to the specs gl_Layer and gl_ViewportIndex should be set for
each call to EmitVertex. A shader should not rely on that EmitVertex
reuses the same memory.
Ref https://www.khronos.org/opengl/wiki/Geometry_Shader#Layered_rendering
```
Warning: gl_Layer and gl_ViewportIndex are GS output variables. As such, every time
you call EmitVertex, their values will become undefined. Therefore, you must set
these variables every time you loop over outputs.
```
Issue detected during development of !129062
Pull Request: https://projects.blender.org/blender/blender/pulls/130506
Recently the GLSL code was changed in Blender. For every GLSL file
the #line directive was added. However due to limitations in Blender
we misuse the indexed based line directive to store a hash. This is not
according to the spec where indexes should index the source inside the
array of sources. In vulkan the indexed based approach is not
'supported' as the compiler inputs only accepts a single file.
We tried to support file based approach but that lead to other issues in
renderdoc. Might be related to that the source file doesn't exist on the
file system.
This PR fixes this by scrambling the #line directive so the
step-by-step debugger can be used. The scrabling only happens when
blender is started with the `--debug-gpu-renderdoc` startup argument.
Pull Request: https://projects.blender.org/blender/blender/pulls/130458
When copying the window to the swap chain the image needs to be copied
upside down to match Vulkan/OpenGL image coordinate differences.
There was an of by 1 error when copying resulting in minor drawing
glitch which was noticeable when looking at the viewport grid.
Pull Request: https://projects.blender.org/blender/blender/pulls/130328
Some Vulkan platforms don't support framebuffers with gaps between the
color attachments. Workbench framebuffers can create gaps.
(`in_front_fb`, `main_fb` when used for wire frame drawing).
This PR implements a detection mechanism to detect gaps. It also disables
features that are not able to comply to this requirement.
Detected when working on #129062
Pull Request: https://projects.blender.org/blender/blender/pulls/130258
The list of vulkan devices is empty. This regression was introduced by
91960b07db. Vulkan needs to initialize the
platform twice. Once when the backend starts, and the second time when
the device is selected. The device list is added when the backend
starts, but was cleared when the device was initialized, making the list
empty.
Pull Request: https://projects.blender.org/blender/blender/pulls/130020
When gl_FragDepth is defined in the fragment shader and the depth isn't
written to the driver would reset the value to 0. This PR fixes this by
not putting the gl_FragDepth in the shader when it uses the
`depth_unchanged` qualifier or doesn't find any usage in the GLSL.
Pull Request: https://projects.blender.org/blender/blender/pulls/130016
Drivers should perform a limit check when creating images and return
`VK_ERROR_OUT_OF_DEVICE_MEMORY`. However there are drivers where this
check is a pass-through and leads to `VK_ERROR_DEVICE_LOST`.
This issue was introduced !128877 and only shows up on official NVIDIA
drivers.
Pull Request: https://projects.blender.org/blender/blender/pulls/129939
When using AMD official driver clearing depth attachments can fail.
I assume it is related to previous pipeline states and dynamic rendering
that don't require the correct pipeline state for clearing depth
attachments.

Co-authored-by: jeroen@blender.org <Jeroen Bakker>
Pull Request: https://projects.blender.org/blender/blender/pulls/129852
Qualcomm driver can not handle the optimized SPIR-V that Blender
creates. According to their driver engineers this is an issue in
shaderc. As we are late in the release process they asked us to disable
the optimizations.
In Blender 4.4 we are planning to update shaderc what might fix the
issue. This should be retested after the update.
Pull Request: https://projects.blender.org/blender/blender/pulls/129775
For C/C++ doc-strings should be located in headers,
move function comments into the headers, in some cases merging
with existing doc-strings, in other cases, moving implementation
notes into the function body.
Avoid measuring the length of strings repeatedly by passing their
length along with their data with `StringRefNull`. Null termination
seems to be necessary still for passing the shader sources to OpenGL.
Though I doubt this is a bottleneck, it's still nice to avoid overhead from
string operations and this helps move in that direction.
Pull Request: https://projects.blender.org/blender/blender/pulls/127702
WITH_VULKAN_GUARDEDALLOC is a development option to use Blenders guarded
allocator when allocating internal vulkan driver resources. It does not provide any benefits
as this should be covered by vulkan validation and drivers are often ignoring this. This
change will remove the option from cmake and source code.
Pull Request: https://projects.blender.org/blender/blender/pulls/129039
Intel Windows drivers for 10th gen and lower has some strange behavior
when using dynamic rendering. It requires pipeline conditions to be met,
when beginning a new rendering scope. This is strange as specs + VVL
notes that these conditions should be met during vkCmdDraw* commands.
Pull Request: https://projects.blender.org/blender/blender/pulls/129055
This change makes unused attachments extension optional.
This extension is fairly new and not all drivers have support for it.
The workaround will create additional pipelines when attachments are
not set.
Pull Request: https://projects.blender.org/blender/blender/pulls/129046
VK_EXT_dynamic_rendering_unused_attachments is required for correct working.
Renderdoc hides this extension, but most platforms do work. However the
Windows Intel driver crashes when using iGPUs; they don't support this
extension at all.
This change does a more strict extension test so drivers that do not
support this extension will fallback to OpenGL. When using renderdoc it
is now allowed to compile blender with `WITH_RENDERDOC=On`.
Future developments are needed to add support for Intel iGPUs on
Windows.
Pull Request: https://projects.blender.org/blender/blender/pulls/128986
Resources are shared, when running multiple contexts on the same thread.
Cycles uses the same context on multiple threads and expected same resources.
This change will introduce a single render graph per context and an updated
resource management. Render graphs are not shared anymore; Resource pools
are still shared, but garbage collection depends on the thread and if
background rendering is used.
Pull Request: https://projects.blender.org/blender/blender/pulls/128983
Cycles uses multiple threads to send commands to the GPU. The current
command buffer structure assumed that all commands from the same context
were send via the same thread. This wasn't the case and could lead to
recording commands to command buffers that are still pending (preparing
commands to send to GPU).
This is fixed by creating a command buffer each time a render graph
submits its work.
Detected when researching #128608
Pull Request: https://projects.blender.org/blender/blender/pulls/128978
When allocating a host visible buffer it could be that the returned
buffer was not host visible and access to the buffer would write to
unallocated memory.
Detected when researching #128608
Pull Request: https://projects.blender.org/blender/blender/pulls/128977
When using cycles in the viewport there it uses render threads and
workers to update the viewport. All threads can record commands to the
queue and needs to be synchronized. This didn't happen leading to
incorrect renders.
Detected when researching #128608
Pull Request: https://projects.blender.org/blender/blender/pulls/128975
Multiple threads can access the same device queue from different
threads. This could happen when doing a cycles preview render, baking
eevee volume probes or generating material previews.
This PR adds a mutex around access to the device queues.
Detected when researching #128608
Pull Request: https://projects.blender.org/blender/blender/pulls/128974
Adds an additional precheck to identify if the app cache dir is correct.
Reduces placing cache files all over the place when the app dir isn't
correct.
Adds a SPIR-V cache that skips frontend compilation for shaders
that are already compiled in a previous run of Blender.
Initially this was postponed to 4.4 but it was observed that
the vulkan backend didn't perform well on Windows in debug
builds. The reason is that the compiler would also be a debug
build which makes compiling a shader really slow. Starting
Blender on a debug build could take minutes.
So the decision was made to give this task a higher priority so
the vulkan backend would become more usable to developers
as well.
The cache is stored in the application cache dir. The SPIR-V
binaries can be used by different Blender versions so there
is no version specific cache folder.
**Sidecar**: SPIR-V files are a stream of bytes. There is no
header information that allow us to validate the stream. To
add basic validations we could add our custom header or
a sidecar. It was chosen to use a sidecar as having the SPIR-V
files unmodified allows us to load them directly in
debug tools for analyzing.
**Retention**: Shaders that are not used are automatically
removed with a retention period of 30 days.
**Shader builder**: Shader builder cannot use the SPIR-V
cache as it uses stubs that returns invalid cache directories.
This would load/save the cache to the location where you
started the build.
Pull Request: https://projects.blender.org/blender/blender/pulls/128741
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