Add SkPathPriv::IsSimpleClosedRect

This function looks for "simple" rect paths. Simple here means begins and ends at a corner and is closed (either manually or with a close verb). Unlike SkPath::isRect this returns the starting point index (using the same start indexing scheme as SkPath::addRect).

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2017313002

Review-Url: https://codereview.chromium.org/2017313002

1 files changed, 8 insertions, 0 deletions

diff --git a/src/core/SkPathPriv.h b/src/core/SkPathPriv.h
index f0bab95030..8689dee197 100644
--- a/src/core/SkPathPriv.h
+++ b/src/core/SkPathPriv.h
@@ -83,6 +83,14 @@ public:
     static void AddGenIDChangeListener(const SkPath& path, SkPathRef::GenIDChangeListener* listener) {
         path.fPathRef->addGenIDChangeListener(listener);
     }
+
+    /**
+     * This returns true for a rect that begins and ends at the same corner and has either a move
+     * followed by four lines or a move followed by 3 lines and a close. None of the parameters are
+     * optional. This does not permit degenerate line or point rectangles.
+     */
+    static bool IsSimpleClosedRect(const SkPath& path, SkRect* rect, SkPath::Direction* direction,
+                                   unsigned* start);
 };
 
 #endif