simplify matrix color filter clamps
We must keep alpha sanely [0,1].
This makes the existing clamps unconditional, which seems the most
compatible with our clients' expectations, and which makes the CPU
backend agree with the GPU backend.
I'm not sure I've got a more principled reason to clamp than those.
Clamping means we can't really concatenate these into a new matrix
filter ever, deleting a bunch of code supporting that and a few
unit tests that thought we could.
(Good candidate for a user-defined effect with user-defined clamping.)
Cq-Include-Trybots: luci.chromium.try:linux-blink-rel
Change-Id: Ib92a4c882320e65ae705833bf623e4e961bc6651
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/200394
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
3 files changed