Add GrTriangulator::TriangulateInnerPolygons
Unlike TriangulateSimpleInnerPolygons, this new method *always*
succeeds. It works by introducing a concept of "breadcrumb" triangles.
The breadcrumb triangles serve as a glue that erases T-junctions
between the outer curves and inner polygon triangulation.
This CL also introduces a test to verify the breadcrumb triangles
actually guarantee to eliminate T-junctions. It works by cancelling
out shared edges in the combined breadcrumb triangles and inner
triangulation, and then verifying that the resulting edge list is
bit-for-bit identical to the outer edges from the original polygon(s).
Bug: skia:10419
Change-Id: Iea8ee2ca3701697246309dceb90e63279aabdfe4
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/353536
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
3 files changed