Add compile-time evaluation of packSnorm2x16.
This is supported by ES3 so we ought to be able to evaluate it at
compile time, but it is not supported on desktop GLSL until #version
420 which limits our ability to test it at runtime.
Change-Id: I4ca8ad7a1fadf9c5325d240f90bb2b68a056b000
Bug: skia:13606
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/577216
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
6 files changed