Add constant twoPiDouble/twoPiFloat to MathExtras.h

Source/platform/transforms/AffineTransform.cpp

Index: Source/platform/transforms/AffineTransform.cpp
diff --git a/Source/platform/transforms/AffineTransform.cpp b/Source/platform/transforms/AffineTransform.cpp
index effb9df601047f879f925d31953641e05ef94923..9a0b33890f3c1876beb630d652ccc58aa10efb34 100644
--- a/Source/platform/transforms/AffineTransform.cpp
+++ b/Source/platform/transforms/AffineTransform.cpp
@@ -317,15 +317,17 @@ void AffineTransform::blend(const AffineTransform& from, double progress)
         srA.angle += srA.angle < 0 ? piDouble : -piDouble;
     }
 
+    const double twoPiDouble = piDouble * 2;

[Justin Novosad, 2014/02/20 19:38:05]

Does this really accomplish anything that the compiler can't optimize on its
own?

+
     // Don't rotate the long way around.
-    srA.angle = fmod(srA.angle, 2 * piDouble);
-    srB.angle = fmod(srB.angle, 2 * piDouble);
+    srA.angle = fmod(srA.angle, twoPiDouble);
+    srB.angle = fmod(srB.angle, twoPiDouble);
 
     if (fabs(srA.angle - srB.angle) > piDouble) {
         if (srA.angle > srB.angle)
-            srA.angle -= piDouble * 2;
+            srA.angle -= twoPiDouble;
         else
-            srB.angle -= piDouble * 2;
+            srB.angle -= twoPiDouble;
     }
 
     srA.scaleX += progress * (srB.scaleX - srA.scaleX);