[skif] Use correct scope when blend affects transparent black
This wasn't showing up in the original BoundsScope CL because that
landed before Ganesh was fixed to actually use fast constraints when
sampling. Ganesh is now fixed and the reland triggers fast constraints
that actually do something.
In the case of imagefilters_xfermodes, the kCanDrawDirectly scoped
analysis thinks that the fast constraint is appropriate (which it
would be). But since the blend mode forces filling the clip with
a shader, it actually can't be drawn directly for external reasons
not visible to analyzeBounds().
Switching to kShaderOnly scope when the blend affects transparent
black detects correctly that shader-tiling is needed in this case.
See https://gold.skia.org/detail?grouping=name%3Dimagefilters_xfermodes%26source_type%3Dgm&digest=8530d6fa17a4a718bdf1086a4649db1e
Bug: b/315351386
Change-Id: I701943320e39aeb55cb0d1d520872cd98c4b8000
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/814297
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
Auto-Submit: Michael Ludwig <michaelludwig@google.com>
1 file changed