tree 2189999a592414e9e5974f1e6fb5a1ebfecb3144
parent 99eb6e2d5abab2cb74e3d413fc99d5cbbfac8765
author lsalzman <lsalzman@mozilla.com> 1464713160 -0700
committer Commit bot <commit-bot@chromium.org> 1464713160 -0700

Filter out degenerate contours in GrConvexPolyEffect

As noticed in a downstream Firefox bug report https://bugzilla.mozilla.org/show_bug.cgi?id=1255062

If a path such as (moveTo, moveTo, lineTo, lineTo, close) is supplied,
and if the non-degenerate contour is convex, the convexity test will
pass, and GrConvexPolyEffect will be used.

However, the path's raw points are used to build the edge list, which
does not filter out degenerate contours. This may cause the polygon to
fail to draw.

This patch ensures that the degenerate contours are filtered out by
using an iterator as the path convexity test does.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2018613003

Review-Url: https://codereview.chromium.org/2018613003