clipShader -- raster implementation
1. pass shader+op down to device
2. bitmapdevice pass it down to rasterclip
3. rasterclip only ever stores at most one shader
- if there is a ctm, fold that into (another) shader
- if the op is difference, invert the sense of alpha
- if there was a previous shader, compose with it
4. pass through to rasterpipelineblitter
5. it prepends the colorPipeline with the clipShader, and stashes its
results in a buffer (fClipShaderBuffer)
6. in each blit, scale/lerp from the buffer before storing the result
Change-Id: I07c7a8a20b9ae95cdcc9954237d115e63819f7c1
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/275798
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
42 files changed