first foray into SkVM image shaders
Basic support for clamp/clamp/nearest/RGBA-8888/premul images.
A couple little changes to make this work:
- add pixel-center offset to shader (x,y)
- change the signature of gather??() calls to work
more naturally with how we let effects build uniforms.
Instead of gathering directly from one of the program
arguments, load the gather base pointer off another
uniforms pointer, just like any other uniform.
- remove the default argument to uniform??() so that
they parallel the new gather??() calls more closely.
There was only one place that was using the default
and I think it's clearer as an explicit 0 offset.
- centralize some more helpers onto skvm::Builder so
we can use the in both SkVMBlitter and SkImageShader.
Some diffs:
- very, very small color diffs probably due to slightly
different math converting between byte and float or blending;
- small sampling coordinate diffs where skvm + SkRP agree,
and the legacy shaders disagree. That's fine by me.
Change-Id: I72634e7fed4f13e6cb41b8067104760f392ea3bf
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/262368
Commit-Queue: Mike Klein <mtklein@google.com>
Reviewed-by: Mike Reed <reed@google.com>
6 files changed