Fix GPU improved noise impl and add to perlinnoise GM.
GPU was recently busted when switching alpha-color type swizzles from
aaaa to 000a.
There was no GM that exercised SkPerlinNoiseShader::MakeImprovedNoise.
It draws wrong before and after this change with the CPU backend.
Bug: skia:10536
Change-Id: I514e304d022fcccae80699a99facafa8ce947e9f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/350916
Auto-Submit: Brian Salomon <bsalomon@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
2 files changed