Fix Wang's formula for cubics
We finally have a reference and derivation of Wang's formula, thanks to
tdenniston@. And it turns out that the formula we had been using for
cubics wasn't quite right. It was overly conservative for certain types
of curves.
This CL fixes the incorrect cubic formulas and adds a citation to the
"Pyramid Algorithms" book. We should now be getting by with fewer linear
segments.
Bug: skia:10419
Change-Id: Ib850c7b4d17b8d9f9abed800cc7cb5f074df6e17
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/331156
Reviewed-by: Tyler Denniston <tdenniston@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
5 files changed