Patch prefers usage of Transform Feedback for hair refinement
as opposed to compute, as vertex work can be pipelined with
existing rendering work which is in-flight.
This approach is ~20% faster depending on the scene. Note that
the current implementation only uses TF, as storage buffer support
is disabled. Though once storage buffer support is added, we should
still use the TF path.
Authored by Apple: Michael Parkin-White
Michael Parkin-White