Update some Sk4px APIs.
Mostly this is about ergonomics, making it easier to do good operations and hard / impossible to do bad ones.
- SkAlpha / SkPMColor constructors become static factories.
- Remove div255TruncNarrow(), rename div255RoundNarrow() to div255(). In practice we always want to round, and the narrowing to 8-bit is contextually obvious.
- Rename fastMulDiv255Round() approxMulDiv255() to stress it's approximate-ness over its speed. Drop Round for the same reason as above... we should always round.
- Add operator overloads so we don't have to keep throwing in seemingly-random Sk4px() or Sk4px::Wide() casts.
- use operator*() for 8-bit x 8-bit -> 16-bit math. It's always what we want, and there's generally no 8x8->8 alternative.
- MapFoo can take a const Func&. Don't think it makes a big difference, but nice to do.
BUG=skia:
Review URL: https://codereview.chromium.org/1202013002
10 files changed