While we won't be transforming shapes, we do need an accurate way to
transform bounding boxes to device space. Right now this just uses
SkM44's mapRect function and converts to/from an SkRect. However,
under the hood SkM44 uses a similar negation trick as skgpu::Rect so
I need to explore if using Rect's internal structure directly will let
us compute the bounding box with fewer operations.
Additionally, SkM44's mapRect clips to a fixed w=epsilon plane, and I
think Transform::mapRect should just do the right thing and handle
w clipping/projection as accurately as possible.
Bug: skia:12466
Change-Id: I08c9df6c40cbcdcd8f622baae222bdf361d59070
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/460578
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
Reviewed-by: Chris Dalton <csmartdalton@google.com>
40b143c174