Implement four more xfermodes with Sk4px.
HardLight, Overlay, Darken, and Lighten are all
~2x faster with SSE, ~25% faster with NEON.
This covers all previously-implemented NEON xfermodes.
3 previous SSE xfermodes remain. Those need division
and sqrt, so I'm planning on using SkPMFloat for them.
It'll help the readability and NEON speed if I move that
into [0,1] space first.
The main new concept here is c.thenElse(t,e), which behaves like
(c ? t : e) except, of course, both t and e are evaluated. This allows
us to emulate conditionals with vectors.
This also removes the concept of SkNb. Instead of a standalone bool
vector, each SkNi or SkNf will just return their own types for
comparisons. Turns out to be a lot more manageable this way.
BUG=skia:
Committed: https://skia.googlesource.com/skia/+/b9d4163bebab0f5639f9c5928bb5fc15f472dddc
CQ_EXTRA_TRYBOTS=client.skia.compile:Build-Ubuntu-GCC-Arm64-Debug-Android-Trybot
Review URL: https://codereview.chromium.org/1196713004
7 files changed