SkCanvas interface for drawing a patch.

src/core/SkGeometry.cpp

Index: src/core/SkGeometry.cpp
diff --git a/src/core/SkGeometry.cpp b/src/core/SkGeometry.cpp
index 646dfb05b9d4f8eddf59c3e0d8ea694c93fabcd3..7fabbc5d6875aa9fe9b3821ed6381291f0bb994e 100644
--- a/src/core/SkGeometry.cpp
+++ b/src/core/SkGeometry.cpp
@@ -1004,6 +1004,20 @@ int SkNumXRayCrossingsForCubic(const SkXRay& pt,
     return num_crossings;
 }
 
+/**
+ * Calculate the approximate arc length given a bezier curve's control points.
+ */
+SkScalar approx_arc_length(SkPoint* points, int count) {
+    if (count < 2) {
+        return 0;
+    }
+    SkScalar arcLength = 0;
+    for (int i = 0; i < count - 1; i++) {
+        arcLength += SkPoint::Distance(points[i], points[i + 1]);
+    }
+    return arcLength;
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 /*  Find t value for quadratic [a, b, c] = d.