Bug 1311244 Part 3 - Extract the computation of center as ComputeCircleOrEllipseCenter(). r=dbaron

MozReview-Commit-ID: A6OTJ9PD43c

--HG--
extra : rebase_source : bcb53b7a0a966e2931c74db475ee8b7573354792

layout/base/ShapeUtils.cpp

@@ -8,6 +8,9 @@
 
 #include <cstdlib>
 
+#include "nsCSSRendering.h"
+#include "nsStyleStruct.h"
+
 namespace mozilla {
 
 nscoord
@@ -30,4 +33,16 @@ ShapeUtils::ComputeShapeRadius(const StyleShapeRadius aType,
   return length;
 }
 
+nsPoint
+ShapeUtils::ComputeCircleOrEllipseCenter(StyleBasicShape* const aBasicShape,
+                                         const nsRect& aRefBox)
+{
+  nsPoint topLeft, anchor;
+  nsSize size(aRefBox.Size());
+  nsImageRenderer::ComputeObjectAnchorPoint(aBasicShape->GetPosition(),
+                                            size, size,
+                                            &topLeft, &anchor);
+  return nsPoint(anchor.x + aRefBox.x, anchor.y + aRefBox.y);
+}
+
 } // namespace mozilla

layout/base/ShapeUtils.h

@@ -10,7 +10,11 @@
 #include "nsCoord.h"
 #include "nsStyleConsts.h"
 
+struct nsPoint;
+struct nsRect;
+
 namespace mozilla {
+class StyleBasicShape;
 
 // ShapeUtils is a namespace class containing utility functions related to
 // processing basic shapes in the CSS Shapes Module.
@@ -28,6 +32,14 @@ struct ShapeUtils final
                                     const nscoord aCenter,
                                     const nscoord aPosMin,
                                     const nscoord aPosMax);
+
+  // Compute the center of a circle or an ellipse.
+  //
+  // @param aRefBox The reference box of the basic shape.
+  // @return The point of the center.
+  static nsPoint ComputeCircleOrEllipseCenter(
+    StyleBasicShape* const aBasicShape,
+    const nsRect& aRefBox);
 };
 
 } // namespace mozilla

layout/svg/nsCSSClipPathInstance.cpp

@@ -113,12 +113,8 @@ nsCSSClipPathInstance::CreateClipPathCircle(DrawTarget* aDrawTarget,
 
   RefPtr<PathBuilder> builder = aDrawTarget->CreatePathBuilder();
 
-  nsPoint topLeft, anchor;
-  nsSize size = nsSize(aRefBox.width, aRefBox.height);
-  nsImageRenderer::ComputeObjectAnchorPoint(basicShape->GetPosition(),
-                                            size, size,
-                                            &topLeft, &anchor);
-  nsPoint center(anchor.x + aRefBox.x, anchor.y + aRefBox.y);
+  nsPoint center =
+    ShapeUtils::ComputeCircleOrEllipseCenter(basicShape, aRefBox);
 
   const nsTArray<nsStyleCoord>& coords = basicShape->Coordinates();
   MOZ_ASSERT(coords.Length() == 1, "wrong number of arguments");
@@ -163,12 +159,8 @@ nsCSSClipPathInstance::CreateClipPathEllipse(DrawTarget* aDrawTarget,
 
   RefPtr<PathBuilder> builder = aDrawTarget->CreatePathBuilder();
 
-  nsPoint topLeft, anchor;
-  nsSize size = nsSize(aRefBox.width, aRefBox.height);
-  nsImageRenderer::ComputeObjectAnchorPoint(basicShape->GetPosition(),
-                                            size, size,
-                                            &topLeft, &anchor);
-  nsPoint center(anchor.x + aRefBox.x, anchor.y + aRefBox.y);
+  nsPoint center =
+    ShapeUtils::ComputeCircleOrEllipseCenter(basicShape, aRefBox);
 
   const nsTArray<nsStyleCoord>& coords = basicShape->Coordinates();
   MOZ_ASSERT(coords.Length() == 2, "wrong number of arguments");