Support querying SignedZeroInfNanPreserve execution mode
from SPIR-V to disable fast-math for individual shaders.
Clean up namespace references in SPIRVToMSLConverter.cpp.
MVKConfiguration access is now global, and the VkInstance provided in the
vkGet/Set/MoltenVKConfigurationMVK() functions is ignored. This allows these
functions to be provided with a VkInstance object that originates from a
different Vulkan layer than MoltenVK, without risking breaking the API.
MVKConfiguration extended to cover all MoltenVK environment variables.
Move all environment variable declarations to MVKEnvironment.h.
Add MVKEnvironment.cpp to define config functions.
Cleanup .m files to use MVKCommonEnvironment.h instead of MVKEnvironment.h.
MVKSmallVector allow constructor to size with default values.
Remove obsolete MVKVector, which was long ago replaced with MVKSmallVector.
Remove unnecessary concrete implementations of template functions that are
used only within a single compilation unit.
Add link to Vulkan SDK Getting Started doc to README.md and
MoltenVK_Runtime_UserGuide.md documents.
Add Github CI badge to README.md, and remove Travis CI badge.
Make document notices of use of Markdown into comments
so they are invisible when using a Markdown reader.
This parameter is intended to indicate the optimal granularity for the
render area. For TBDR GPUs, this will be the tile size. IMR GPUs
continue to use 1x1.
Apple GPUs support tile sizes of 16x16, 32x16, and 32x32. But, we can't
read the tile size used for a Metal render pass until a render command
encoder has been created. So for now, hardcode 32x32 for TBDR GPUs.
Memoryless textures cannot use `Load`/`Store` actions, because there is
no memory to load from or store to. So don't use these actions, even if
we're not rendering to the whole thing.
Multiple subpasses might be a problem. Tessellation and indirect
multiview *will* be problems, because these require us to interrupt the
render pass in order to do compute--and that causes us to use `Store`
unconditionally.
One option, which I've mentioned before, is using tile shaders for these
cases. But I haven't looked seriously into that yet. The other involves
a subtle distinction between Metal's `MTLStorageModeMemoryless` and
Vulkan's `VK_MEMORY_TYPE_LAZILY_ALLOCATED_BIT`: the former *never*
commits memory; while the latter doesn't commit memory *at first*, but
may do so later. If we find that we're going to need to `Store` to a
`LAZILY_ALLOCATED` image, then what we can do is replace the
`Memoryless` texture with one with a real backing store in `Private`
memory. This change does not do that yet. It'll require some more
thought.
As for multiple subpasses, I eventually want to look into optimizing
render passes by shuffling the subpasses around to minimize the need to
load and store attachments from/to memory, which TBDR GPUs absolutely
hate. That should help with this problem, too.
Metal does not allow color write masks with this format where some but
not all of the channels are disabled. Either all must be enabled or none
must be enabled. Presumably, this is because of the shared exponent.
This is just good enough to stop the validation layer from violently
terminating the program. To implement this properly requires using
framebuffer fetch, with a change to SPIRV-Cross. Luckily, the only GPUs
that support `RGB9E5` rendering also support framebuffer fetch.
Honestly, I don't understand why Apple's drivers don't do this.
