Below MSL 3.1, SPIRV-Cross emulates an image atomic with a raw device pointer
beside the texture, laid out like a linear image. A block-linear image's Metal
texture is a deswizzled copy, so its atomics went to a scratch buffer nothing
read (Pokemon Legends: Z-A's atomic max into texture 302), and a 3D image's
pointer was indexed with the int3 coordinate itself, which does not compile
(16 shaders of Octopath Traveler 0, 5 of Ghost Trick, 8 of FINAL FANTASY
RESONANCE).
- dmsh_atomic.py: shaders with image atomics (OpImageTexelPointer) are written
at MSL 3.1, so the atomics run on the image's own texture; every other
shader keeps its MSL 2.3 source byte for byte. MSL that still holds the
pointer form fails the build.
- Translator (TranslationFlags.MetalImageAtomics, renamed from
Msl23ImageAtomics): admits 3D images and SUATOM.CAS (Metal's texture
compare-exchange); the IGN coordinate guard is unchanged.
- Host: the IMGA pointer binding, the scratch buffer and the layout admission
are gone. NVN images of R32Uint / R32Sint take MTLTextureUsageShaderAtomic
(img_usage, kept by tex_upgrade: Metal leaves that bit out of the usage
property); any other texture in an atomic slot is replaced by an
atomic-capable write sink with a red line.
- Chain a4e2088c2e69 (with main's vertex-output padding). Tested on
chain 0ce4b5e8aefb, this change before that rebase: Octopath Traveler 0
builds all 10,324 shaders, Z-A all
28,603, Ghost Trick's five 3D-atomic shaders build. Mac runs of both games
under the Metal API validation layer showed no validation error (Octopath
Traveler 0 to frame 14,400, its particle atomics on buffer texture 2049;
Z-A to frame 12,000 through the atomic max on texture 302). Synthetic
atomics and CAS run on buffer, 2D, 2D-array and 3D textures of a Mac GPU
(test_image_atomic_bounds.py, t_atomic_return.m).
GitHub issue #290: at 40b643b Octopath Traveler 0 already built 10,308 of
10,324 shaders (2e655b7 fixed the returning atomics); the 16 left were the 3D
ones, which build now. Not checked: an iPhone, FINAL FANTASY RESONANCE's
library, the picture of Z-A's atomic scene.
seedds
f8642c480f