Support combining per-vertex coverage with color in default GP vertex shader
Leverage this in ops that use tessellation with per-vertex coverage, to
move the (color * coverage) work into the vertex shader.
For the tessellating path renderer, color is always uniform, but we were
sending it per-vertex. Added support to the default GP for routing the
uniform color to the vertex shader (when there is per-vertex coverage and
coverage can be folded into alpha). The end result is that we do less work
on the CPU, and send less data (for incompatible blend modes) or the same
amount (for compatible blend modes).
Finally, because color is never sent through a vertex attribute, this
solves wide color (and avoids the vertex bloat that would have happened
when using half-floats). For the linearizing convex path renderer, do the
usual fix for wide color.
PS6 is the "clean" version of this CL, later versions are guarded to
rebaseline layout tests.
Bug: skia:
Change-Id: I7fa87219177d36db800463d4492b78f2cb14a1c3
Reviewed-on: https://skia-review.googlesource.com/c/179996
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
6 files changed