All the OSL matrix functions had been implemented using the
`Transform` utility of Cycles, but that's built around a 4x3 matrix,
when the OSL matrix functions are working with 4x4 matrices.
This resulted in them not producing results consistent with the
CPU implementation.
This fixes that by making use of the `ProjectionTransform` utility
of Cycles instead, because it's built around a 4x4 matrix. Since
matrix inversion is required, I had to make a few more utility
functions available on the GPU (except Metal, due to use of
references/pointers without specification) that were previously
CPU-only.
Co-authored-by: Brecht Van Lommel <brecht@blender.org>
Pull Request: https://projects.blender.org/blender/blender/pulls/110102
d0dd587b60