This patch adds support for compilation and execution of GLSL compute shaders. This, along with a few systematic changes and fixes, enable realtime compositor functionality with the Metal backend on macOS. A number of GLSL source modifications have been made to add the required level of type explicitness, allowing all compilations to succeed.
GLSL Compute shader compilation follows a similar path to Vertex/Fragment translation, with added support for shader atomics, shared memory blocks and barriers.
Texture flags have also been updated to ensure correct read/write specification for textures used within the compositor pipeline. GPU command submission changes have also been made in the high level path, when Metal is used, to address command buffer time-outs caused by certain expensive compute shaders.
Authored by Apple: Michael Parkin-White
Ref T96261
Ref T99210
Reviewed By: fclem
Maniphest Tasks: T99210, T96261
Differential Revision: https://developer.blender.org/D16990
AMD GPUs do not appear to produce consistent results with other GPUs when using textureGather in the Metal backend. Disabling for now to ensure correct function of outline rendering.
This may require an additional sub-pixel offset in the texture sampling calls, to achieve correct behaviour.
Authored by Apple: Michael Parkin-White
Ref T103412
Ref T96261
Reviewed By: fclem
Maniphest Tasks: T103412, T96261
Differential Revision: https://developer.blender.org/D16934
Full support for translation and compilation of shaders in Metal, using
GPUShaderCreateInfo. Includes render pipeline state creation and management,
enabling all standard GPU viewport rendering features in Metal.
Authored by Apple: Michael Parkin-White, Marco Giordano
Ref T96261
Reviewed By: fclem
Maniphest Tasks: T96261
Differential Revision: https://developer.blender.org/D15563
MTLFrameBuffer has been implemented to support creation of RenderCommandEncoders, along with supporting functionality in the Metal Context.
Optimisation stubs for GPU_framebuffer_bind_ext has been added, which enables specific assignment of attachment load-store ops at the bind level, rather than on a framebuffer object as a whole.
Begin and end frame markers are used to encapsulate frame boundaries for explicit workload submission. This is required for explicit APIs where implicit flushing of work does not occur.
Ref T96261
Reviewed By: fclem
Maniphest Tasks: T96261
Differential Revision: https://developer.blender.org/D15027
This covers implementation of the GPUTexture abstraction for the Metal backend, with additional utility functionality as required.
Some components have been temporarily disabled pending dependencies on upcoming Metal backend components, and these will be addressed as the backend is fleshed out.
One core challenge addressed in the Metal backend is the requirement for read/update routines for textures. MTLBlitCommandEncoders offer a limited range of the full functionality provided by OpenGLs texture update and read functions such that a series of compute kernels have been implemented to provide advanced functionality such as data format conversion and partial/swizzled component updates.
This diff is provided in full, but if further division is required for purposes of code review, this can be done.
Authored by Apple: Michael Parkin-White
Ref T96261
Reviewed By: fclem
Maniphest Tasks: T96261
Differential Revision: https://developer.blender.org/D14543
Adding WITH_METAL option to CMAKE to guard compilation for macOS only. Implemented stub METALBackend to mirror GPUBackend interface and added capabilities initialisation, along with API initialisation paths.
Global rendering coordination commands added to backend with GPU_render_begin and GPU_render_end() commands globally wrapping GPU work. This is required for Metal to ensure temporary resources are generated within an NSAutoReleasePool and freed accordingly.
Authored by Apple: Michael Parkin-White, Vil Harvey, Marco Giordano, Michael Jones, Morteza Mostajabodaveh, Jason Fielder
Ref T96261
Reviewed By: fclem
Maniphest Tasks: T96261
Differential Revision: https://developer.blender.org/D14293
