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>
4201cdab18