[skottie] Fix text selector sub-unit range handling
The current logic modulates the shape generator output by its fractional
coverage, ignoring constant lo/hi contributions.
But RampUp/RampDown have non-zero hi/lo constant coverage, which needs
to be accounted for.
The correct behavior is to perform a 3-way weighted average of the
lo/hi/generator, based on their relative weights.
Change-Id: Ide0ed2ae590bbce2b56c0c65008b64632b987905
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/218962
Commit-Queue: Florin Malita <fmalita@chromium.org>
Commit-Queue: Ben Wagner <bungeman@google.com>
Auto-Submit: Florin Malita <fmalita@chromium.org>
Reviewed-by: Ben Wagner <bungeman@google.com>
1 file changed