Since the introduction of storage buffers in Blender, the calling
code has been responsible for ensuring the buffer meets allocation
requirements. All backends require the allocation size to be divisible
by 16 bytes. Until now, this was sufficient, but with GPU subdivision
changes, an external library must also adhere to these requirements.
For OpenSubdiv (OSD), some buffers are not 16-byte aligned, leading
to potential misallocation. Currently, this is mitigated by allocating
a few extra bytes, but this approach has the drawback of potentially
reading unintended bytes beyond the source buffer.
This PR adopts a similar approach to vertex buffers: the backend handles
extra byte allocation while ensuring data uploads and downloads function
correctly without requiring those additional bytes.
No changes were needed for Metal, as its allocation size is already
aligned to 256 bytes.
**Alternative solutions considered**:
- Copying the CPU buffer to a larger buffer when needed (performance impact).
- Modifying OSD buffers to allocate extra space (requires changes to an external library).
- Implementing GPU_storagebuf_update_sub.
Ref #135873
Pull Request: https://projects.blender.org/blender/blender/pulls/135716
`GLBatch::draw_indirect` has additional overhead compared to
`GLBatch::draw`, and can become a bottleneck in scenes that require
many draw calls (ie. with too many unique meshes).
The performance difference is almost exclusively caused by the
`GL_COMMAND_BARRIER_BIT` barrier that happens on every call.
This PR adds a `GPU_storagebuf_sync_as_indirect_buffer` function that
can be used to place the barrier only once after filling the indirect
buffer content.
This function is a no-op in Vulkan and Metal since they don't need the
barrier.
Pull Request: https://projects.blender.org/blender/blender/pulls/117561
NDEBUG is part of the C standard and disables asserts. Only this will
now be used to decide if asserts are enabled.
DEBUG was a Blender specific define, that has now been removed.
_DEBUG is a Visual Studio define for builds in Debug configuration.
Blender defines this for all platforms. This is still used in a few
places in the draw code, and in external libraries Bullet and Mantaflow.
Pull Request: https://projects.blender.org/blender/blender/pulls/115774
PR Introduces GPU_storagebuf_sync_to_host as an explicit routine to
flush GPU-resident storage buffer memory back to the host within the
GPU command stream.
The previous implmentation relied on implicit synchronization of
resources using OpenGL barriers which does not match the
paradigm of explicit APIs, where indiviaul resources may need
to be tracked.
This patch ensures GPU_storagebuf_read can be called without
stalling the GPU pipeline while work finishes executing. There are
two possible use cases:
1) If GPU_storagebuf_read is called AFTER an explicit call to
GPU_storagebuf_sync_to_host, the read will be synchronized.
If the dependent work is still executing on the GPU, the host
will stall until GPU work has completed and results are available.
2) If GPU_storagebuf_read is called WITHOUT an explicit call to
GPU_storagebuf_sync_to_host, the read will be asynchronous
and whatever memory is visible to the host at that time will be used.
(This is the same as assuming a sync event has already been signalled.)
This patch also addresses a gap in the Metal implementation where
there was missing read support for GPU-only storage buffers.
This routine now uses a staging buffer to copy results if no
host-visible buffer was available.
Reading from a GPU-only storage buffer will always stall
the host, as it is not possible to pre-flush results, as no
host-resident buffer is available.
Authored by Apple: Michael Parkin-White
Pull Request: https://projects.blender.org/blender/blender/pulls/113456
Listing the "Blender Foundation" as copyright holder implied the Blender
Foundation holds copyright to files which may include work from many
developers.
While keeping copyright on headers makes sense for isolated libraries,
Blender's own code may be refactored or moved between files in a way
that makes the per file copyright holders less meaningful.
Copyright references to the "Blender Foundation" have been replaced with
"Blender Authors", with the exception of `./extern/` since these this
contains libraries which are more isolated, any changed to license
headers there can be handled on a case-by-case basis.
Some directories in `./intern/` have also been excluded:
- `./intern/cycles/` it's own `AUTHORS` file is planned.
- `./intern/opensubdiv/`.
An "AUTHORS" file has been added, using the chromium projects authors
file as a template.
Design task: #110784
Ref !110783.
A lot of files were missing copyright field in the header and
the Blender Foundation contributed to them in a sense of bug
fixing and general maintenance.
This change makes it explicit that those files are at least
partially copyrighted by the Blender Foundation.
Note that this does not make it so the Blender Foundation is
the only holder of the copyright in those files, and developers
who do not have a signed contract with the foundation still
hold the copyright as well.
Another aspect of this change is using SPDX format for the
header. We already used it for the license specification,
and now we state it for the copyright as well, following the
FAQ:
https://reuse.software/faq/
The goal is to solve confusion of the "All rights reserved" for licensing
code under an open-source license.
The phrase "All rights reserved" comes from a historical convention that
required this phrase for the copyright protection to apply. This convention
is no longer relevant.
However, even though the phrase has no meaning in establishing the copyright
it has not lost meaning in terms of licensing.
This change makes it so code under the Blender Foundation copyright does
not use "all rights reserved". This is also how the GPL license itself
states how to apply it to the source code:
<one line to give the program's name and a brief idea of what it does.>
Copyright (C) <year> <name of author>
This program is free software ...
This change does not change copyright notice in cases when the copyright
is dual (BF and an author), or just an author of the code. It also does
mot change copyright which is inherited from NaN Holding BV as it needs
some further investigation about what is the proper way to handle it.
The previous API for clearing storage buffers was following the OpenGL
api. OpenGL has many options to support for data conversions, striding
and sizzling. Metal and Vulkan don't have these features and we have to
deal it ourselves.
Blender internally only uses a tiny subset for what is possible in
OpenGL. Making the current API to difficult to implement on our future
platforms as we had to implement all cases, most even not used at all.
By changing the API we make future development easier as we only need
to implement what we are actually using.
**New API**
`GPU_storagebuf_clear(GPUStorageBuf* ssbo, uint32_t clear_value)`
Related issue: #105492
Pull Request: https://projects.blender.org/blender/blender/pulls/105521
This patch adds initial support for compute shaders to
the vulkan backend. As the development is oriented to the test-
cases we have the implementation is limited to what is used there.
It has been validated that with this patch that the following test
cases are running as expected
- `GPUVulkanTest.gpu_shader_compute_vbo`
- `GPUVulkanTest.gpu_shader_compute_ibo`
- `GPUVulkanTest.gpu_shader_compute_ssbo`
- `GPUVulkanTest.gpu_storage_buffer_create_update_read`
- `GPUVulkanTest.gpu_shader_compute_2d`
This patch includes:
- Allocating VkBuffer on device.
- Uploading data from CPU to VkBuffer.
- Binding VkBuffer as SSBO to a compute shader.
- Execute compute shader and altering VkBuffer.
- Download the VkBuffer to CPU ram.
- Validate that it worked.
- Use device only vertex buffer as SSBO
- Use device only index buffer as SSBO
- Use device only image buffers
GHOST API has been changed as the original design was created before
we even had support for compute shaders in blender. The function
`GHOST_getVulkanBackbuffer` has been separated to retrieve the command
buffer without a backbuffer (`GHOST_getVulkanCommandBuffer`). In order
to do correct command buffer processing we needed access to the queue
owned by GHOST. This is returned as part of the `GHOST_getVulkanHandles`
function.
Open topics (not considered part of this patch)
- Memory barriers & command buffer encoding
- Indirect compute dispatching
- Rest of the test cases
- Data conversions when requested data format is different than on device.
- GPUVulkanTest.gpu_shader_compute_1d is supported on AMD devices.
NVIDIA doesn't seem to support 1d textures.
Pull-request: #104518
This allows using the Graphic API to copy buffer data.
The GPU module do not expose untyped buffers even if that's what most API
do, so the copy function need to be strongly typed.
Contains GL backend implementation.
This is a faster way to clear a buffer instead of reuploading new data.
It is equivalent to `memset` and runs directly on the GPU.
This is better to clear huge buffers and to avoid the sync cost of data upload.
