Merge topic 'pi-precision' into master

fa50ef90 Fix precision issues when using vtkMath::Pi()

Common/vtkCylindricalTransform.cxx

@@ -15,7 +15,7 @@
 #include "vtkCylindricalTransform.h"
 #include "vtkObjectFactory.h"
 #include "vtkMath.h"
-#include <math.h>
+#include <cmath>
 #include <stdlib.h>
 
 vtkStandardNewMacro(vtkCylindricalTransform);
@@ -102,7 +102,7 @@ void vtkRectangularToCylindrical(const T inPoint[3], T outPoint[3])
   else
     {
     // Change range to [0, 2*Pi], otherwise the same as atan2(y, x)
-    outPoint[1] = static_cast<T>(vtkMath::Pi() + atan2(-y, -x));
+    outPoint[1] = T(vtkMath::DoublePi()) + atan2(-y, -x);
     }
   outPoint[2] = z;
 }

Common/vtkMath.cxx

@@ -2973,7 +2973,7 @@ int vtkMath::PointIsWithinBounds(double point[3], double bounds[6], double delta
 //----------------------------------------------------------------------------
 double vtkMath::GaussianAmplitude(const double variance, const double distanceFromMean)
 {
-  return 1./(sqrt(2.*vtkMath::Pi() * variance)) * exp(-(pow(distanceFromMean,2))/(2.*variance));
+  return 1./(sqrt(2.*vtkMath::DoublePi() * variance)) * exp(-(pow(distanceFromMean,2))/(2.*variance));
 }
 
 //----------------------------------------------------------------------------

Common/vtkSphericalTransform.cxx

@@ -15,7 +15,7 @@
 #include "vtkSphericalTransform.h"
 #include "vtkObjectFactory.h"
 #include "vtkMath.h"
-#include <math.h>
+#include <cmath>
 #include <stdlib.h>
 
 vtkStandardNewMacro(vtkSphericalTransform);
@@ -112,7 +112,7 @@ void vtkRectangularToSpherical(const T inPoint[3], T outPoint[3])
   else
     {
     // Change range to [0, 2*Pi], otherwise the same as atan2(y, x)
-    outPoint[2] = vtkMath::Pi() + atan2(-y, -x);
+    outPoint[2] = T(vtkMath::DoublePi()) + atan2(-y, -x);
     }
 }