Added a MinimumAngle iVar to the API; set defaults

Change-Id: I49fda312ce73277471a5c99ffe6fa3f14d7477fa

Hybrid/vtkPolarAxesActor.cxx

@@ -66,6 +66,7 @@ void vtkPolarAxesActor::PrintSelf( ostream& os, vtkIndent indent )
 
   os << indent << "Maximum Radius" << this->MaximumRadius << endl;
   os << indent << "Auto-Scale Radius" << this->AutoScaleRadius << endl;
+  os << indent << "Minimum Angle" << this->MinimumAngle << endl;
   os << indent << "Maximum Angle" << this->MaximumAngle << endl;
   os << indent << "Radial Units (degrees): "
      << ( this->RadialUnits ? "On\n" : "Off\n" ) << endl;
@@ -130,6 +131,9 @@ vtkPolarAxesActor::vtkPolarAxesActor() : vtkActor()
   // Do not auto-scale radius by default
   this->AutoScaleRadius = false;
 
+  // Default minimum polar angle
+  this->MinimumAngle = 0.;
+
   // Default maximum polar angle
   this->MaximumAngle = VTK_DEFAULT_MAXIMUM_POLAR_ANGLE;
 
@@ -680,7 +684,7 @@ void vtkPolarAxesActor::BuildPolarAxisTicks( double x0 )
   axis->SetMajorRangeStart( 0. );
   axis->SetDeltaRangeMajor( delta );
   axis->SetMajorStart( VTK_AXIS_TYPE_X, x0 );
-  // Build in numerical robustness
+  // Build in numerical robustness to avoid truncation errors at endpoint
   delta *= VTK_POLAR_AXES_ACTOR_RTOL;
   axis->SetDeltaMajor( VTK_AXIS_TYPE_X, delta );
 }

Hybrid/vtkPolarAxesActor.h

@@ -98,17 +98,18 @@ public:
   vtkSetMacro( AutoScaleRadius,bool );
   vtkGetMacro( AutoScaleRadius,bool );
 
+  // Description:
+  //  Set/Get the minimum radius of the polar coordinates (in degrees).
+  // Default: 0.
+  vtkSetClampMacro( MinimumAngle, double, 0., 360. );
+  vtkGetMacro( MinimumAngle, double );
+
   // Description:
   //  Set/Get the maximum radius of the polar coordinates (in degrees).
   // Default: VTK_DEFAULT_MAXIMUM_POLAR_ANGLE
   vtkSetClampMacro( MaximumAngle, double, 0., 360. );
   vtkGetMacro( MaximumAngle, double );
 
-  // Description:
-  // Set/Get the RebuildAxes flag
-  vtkSetMacro( RebuildAxes, bool );
-  vtkGetMacro( RebuildAxes, bool );
-
   // Description: Set/Get whether angle units (degrees) are used to label radial axes 
   // Default: true
   vtkSetMacro( RadialUnits, bool ); 
@@ -272,7 +273,11 @@ protected:
   bool AutoScaleRadius;
 
   // Description:
-  // Maximum polar angle (minimum is always 0)
+  // Minimum polar angle
+  double MinimumAngle;
+
+  // Description:
+  // Maximum polar angle
   double MaximumAngle;
 
   // Description:
@@ -293,8 +298,6 @@ protected:
   // Control variables for radial axes
   vtkAxisActor** RadialAxes;
 
-  bool RebuildAxes;
-
   // Description:
   // Title to be used for the polar axis
   // NB: The other axes use the polar angle value as a title