SkImageFilters::Paint did not use every slot of the SkPaint, with only
its color, alpha, color filter, and shader having a meaningful effect on
the image filter result. It was always blended into a transparent dst,
so blend mode wasn't very relevant, and it was always filled to whatever
required geometry, so stroke style, path effect, and mask filters were
ignored or not well specified.
Color, alpha, and color filter can all be combined into an SkShader, so
a more constrained SkImageFilters::Shader provides the same useful
capabilities without as many surprises.
SkImageFilters::Paint still exists, but is deprecated to be removed
once I've confirmed clients aren't depending on it.
Bug: skia:9310
Change-Id: I11a82bda1a5d440726cf4e2b5bfaae4929568679
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/323680
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
This new changelist also introduces a new image filter called SkRectShaderImageFilter which is make to simply apply a shader on a region without using any inputs.
TEST=Added ShaderImageFilter test
Review URL: https://codereview.appspot.com/7300046
git-svn-id: http://skia.googlecode.com/svn/trunk@7808 2bbb7eff-a529-9590-31e7-b0007b416f81
