PS1 is the exact contents of src/gpu/v1/ClipStack.* copied to
experimental/graphite/src.
PS2+ shows all the changes to remove v1-only features and update some of
the types over to what graphite uses. The major changes are:
1. FragmentProcessors, clip atlases, stencil mask writing, and SW mask
writing are gone.
2. SW mask caching and tracking are gone.
3. Graphite is effectively in the "forceAA" mode that the original clip
stack supported. So branches that focused on non-AA, or comparing AA
or handling cases where elements' AA mismatched could all be removed.
4. Updated to use Graphite's Shape and Transform classes. Did not go as
far as moving the bounds from SkIRect to Rect, but since everything
is AA, it will be much simpler to switch to comparing float bounds
directly and not worry about rounding in or out. That's a more
substantial change so will come later.
5. The original ClipStack had a "Draw" type that was used to compute
clip interactions between SaveRecords and Elements. It was always
just device-space bounds because of limitations of the GrClip API.
In Graphite, we can use the exact same set of info for Draws and
Elements, making interaction tests share code and be more accurate.
Since that's a more involved change, I just removed the simpler Draw
type from this version for now.
6. Tried to add TODOs for what logic and extra state will need to be
added to actually apply graphite's clip stack as depth-only draws.
Bug: skia:12698
Change-Id: I418703e8f759cd5e1ddd1e302a864bf2204cf040
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/525516
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
7b04832cbe