rhi: Metal tessellation shader input output interface blocks

Add support for shader input output interface blocks in Metal
tessellation pipelines.  This feature is builtin to other rhi supported
tessellation backends (OpenGL/Vulkan).

Metal tessellation is implemented as compute pipelines for vert and
tesc, and a render pipeline for tese and frag.  The shader conversion
from GLSL is handled by SPIRV-Cross, which has a particular way of doing
things.  Rhi must setup the vertex inputs for the tese - frag render
pipeline to read from buffers written by the tesc compute pipeline,
following SPIRV-Cross conventions.  This includes ensuring correct
memory alignment per MSL Specification.

In order to enable input output interface blocks, reflection of struct
members of QShaderDescription::InOutVariable is required.  Reflection of
QShaderDescription::BuiltinVariable array dimensions is also required to
support variable size tese builtin input gl_ClipDistance.

An acompanying patch to QtShaderTools is required.

Change-Id: Id94e86caef211485afc187bb79fe3d0619d02cf0
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

1 files changed, 0 insertions, 0 deletions

diff --git a/tests/auto/gui/rhi/qrhi/data/tessinterfaceblocks.frag.qsb b/tests/auto/gui/rhi/qrhi/data/tessinterfaceblocks.frag.qsb
new file mode 100644
index 0000000000..7eda4bed2d
--- /dev/null
+++ b/tests/auto/gui/rhi/qrhi/data/tessinterfaceblocks.frag.qsb