Bug 931996 - Add an AppendEllipseToPath helper to Moz2D. r=Bas

gfx/2d/PathHelpers.cpp

@@ -150,6 +150,18 @@ AppendRoundedRectToPath(PathBuilder* aPathBuilder,
   aPathBuilder->Close();
 }
 
+void
+AppendEllipseToPath(PathBuilder* aPathBuilder,
+                    const Point& aCenter,
+                    const Size& aDimensions)
+{
+  Size halfDim = aDimensions / 2.0;
+  Rect rect(aCenter - Point(halfDim.width, halfDim.height), aDimensions);
+  Size radii[] = { halfDim, halfDim, halfDim, halfDim };
+
+  AppendRoundedRectToPath(aPathBuilder, rect, radii);
+}
+
 } // namespace gfx
 } // namespace mozilla
 

gfx/2d/PathHelpers.h

@@ -98,6 +98,17 @@ GFX2D_API void AppendRoundedRectToPath(PathBuilder* aPathBuilder,
                                        const Size(& aCornerRadii)[4],
                                        bool aDrawClockwise = true);
 
+/**
+ * Appends a path represending an ellipse to the path being built by
+ * aPathBuilder.
+ *
+ * The ellipse extends aDimensions.width / 2.0 in the horizontal direction
+ * from aCenter, and aDimensions.height / 2.0 in the vertical direction.
+ */
+GFX2D_API void AppendEllipseToPath(PathBuilder* aPathBuilder,
+                                   const Point& aCenter,
+                                   const Size& aDimensions);
+
 } // namespace gfx
 } // namespace mozilla