SkColorFilter::onProgram()
Before we write too many of these, let's get a program() / onProgram()
wrapper in place for SkColorFilter. When a filter claims it doesn't
change alpha, we can skip any work it might do to "calculate" that
unchanged alpha (e.g. 0*r + 0*g + 0*b + 1*a + 0) and instead just
save and restore the orignal alpha.
SkShader already has this same program() / onProgram() setup, and uses
it similarly to force any shader that claims to be opaque to be opaque,
replacing any math (or sometimes even memory loads) that shader may have
done to produce alpha with a simple splat(1.0f).
Change-Id: Ica916926506df3a48b4d718545ea64dd95b457af
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/261134
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
4 files changed