Commit Graph

5 Commits

Author SHA1 Message Date
Chip Davis
fd738e3387 MSL: Adjust FragCoord for sample-rate shading.
In Metal, the `[[position]]` input to a fragment shader remains at
fragment center, even at sample rate, like OpenGL and Direct3D. In
Vulkan, however, when the fragment shader runs at sample rate, the
`FragCoord` builtin moves to the sample position in the framebuffer,
instead of the fragment center. To account for this difference, adjust
the `FragCoord`, if present, by the sample position. The -0.5 offset is
because the fragment center is at (0.5, 0.5).

Also, add an option to force sample-rate shading in a fragment shader.
Since Metal has no explicit control for this, this is done by adding a
dummy `[[sample_id]]` which is otherwise unused, if none is already
present. This is intended to be used from e.g. MoltenVK when a
pipeline's `minSampleShading` value is nonzero.

Instead of checking if any `Input` variables have `Sample`
interpolation, I've elected to check that the `SampleRateShading`
capability is present. Since `SampleId`, `SamplePosition`, and the
`Sample` interpolation decoration require this cap, this should be
equivalent for any valid SPIR-V module. If this isn't acceptable, let me
know.
2020-11-23 10:30:24 -06:00
Hans-Kristian Arntzen
a07441568e Overhaul how we deal with reserved identifiers.
- Do not silently drop reserved identifiers in the parser. This makes it
  possible to reflect identifiers which are reserved by the
  cross-compiler module.
- Instead of dropping the name, emit _RESERVED_IDENTIFIER_FIXUP in the
  source to make it clear that a name has been rewritten.
- Document what is reserved and not.
2020-08-21 16:33:27 +02:00
Hans-Kristian Arntzen
e1600d4df8 MSL: Use input attachment index directly for resource index fallback. 2020-07-06 09:49:46 +02:00
Hans-Kristian Arntzen
d1479f871a MSL: Do not generate UnsafeArray<> for any array inside buffer objects.
This avoids a lot of huge code changes.
Arrays generally cannot be copied in and out of buffers, at least no
compiler frontend seems to do it.

Also avoids a lot of issues surrounding packed vectors and matrices.
2019-10-24 12:22:30 +02:00
Lukas Hermanns
c236ca4572 Moved all UE4 test shaders into 'shaders-ue4/' folder. 2019-10-23 17:39:05 -04:00