InputPatch parameters to patch constant functions were not using the
internal (temporary) variable type. That could cause validation errors
if the input patch had a mixture of builtins and user qualified members.
This uses the entry point's internal form.
There is currently a limitation: if an InputPatch is used in a PCF,
it must also have appeared in the main entry point's parameter list.
That is not a limitation of HLSL. Currently that situation is detected
and an "implemented" error results. The limitation can be addressed,
but isn't yet in the current form of the PR.
Hull shaders have an implicitly arrayed output. This is handled by creating an arrayed form of the
provided output type, and writing to the element of it indexed by InvocationID.
The implicit indirection into that array was causing some troubles when copying to a split
structure. handleAssign was able to handle simple symbol lvalues, but not an lvalue composed
of an indirection into an array.
There was some ambiguity/contradiction in this behavior, and
Khronos decided glslang should always have these outside blocks,
rather than have stage/vendor/target variations.
There were several locations in TGlslangToSpvTraverser::handleUserFunctionCall testing for
whether a fn argument should be in the lvalue or rvalue array. They must get the same
result for indexing sanity, but had slightly different logic.
They're now forced into the same test.
Changes:
(1) Allow clip/cull builtins as both input and output in the same shader stage. Previously,
not enough data was tracked to handle this.
(2) Handle the extra array dimension in GS inputs. The synthesized external variable can
now be created with the extra array dimension if needed, and the form conversion code is
able to handle it as well.
For example, both of these GS inputs would result in the same synthesized external type:
triangle in float4 clip[3] : SV_ClipDistance
triangle in float2 clip[3][2] : SV_ClipDistance
In the second case, the inner array dimension packs with the 2-vector of floats into an array[4],
which there is an array[3] of due to the triangle geometry.
While adding geometry stage support for clip/cull, it transpired that the
existing clip/cull support was not setting the type of the result of indexing
into the clup/cull variable. That's a defect independent of the geometry
support, so to simplify the geometry PR, this is addressed separately.
It doesn't appear to change the generated SPIR-V, but that's probably down to
something else tolerating a bad input.
HLSL allows a range of types for clip and cull distances. There are
three dimensions, including arrayness, vectorness, and semantic ID.
SPIR-V requires clip and cull distance be a single array of floats in
all cases.
This code provides input side conversion between the SPIR-V form and
the HLSL form. (Output conversion was added in PR #947 and #997).
This PR extends HlslParseContext::assignClipCullDistance to cope with
the input side conversion. Not as much changed as appears: there was
also a lot of renaming to reflect the fact that the code now handles
either direction.
Currently, non-{frag,vert} stages are not handled, and are explicitly
rejected.
Fixes#1026.
