tree dea8644d31df5b148fc95469c74fe761bc018260
parent 5db44aa2aa4a3a1b9ce1fe7e22c54c8d9b61f51d
author dvonbeck <dvonbeck@google.com> 1469811236 -0700
committer Commit bot <commit-bot@chromium.org> 1469811236 -0700

GrFP can express distance vector field req.,  program builder declares variable for it

This update allows fragment processors to require a field of vectors to the nearest edge. This requirement propagates:

- from child FPs to their parent
- from parent FPs to the GrPaint
- from GrPaint through the PipelineBuilder into GrPipeline
- acessed from GrPipeline by GrGLSLProgramBuilder

GrGLSL generates a variable for the distance vector and passes it down to the GeometryProcessor->emitCode() method.

This CL's base is the CL for adding the BevelNormalSource API: https://codereview.chromium.org/2080993002

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2114993002

Review-Url: https://codereview.chromium.org/2114993002