Fix NVPR with explicitly sampled FPs.

Use uniforms rather than fixed function computed varyings to implement
coord transforms for FPs that are sampled explicitly.

Change-Id: I43be3f9649550e36dbb4d1f72090a497dfeb0d31
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/273798
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
1 file changed