ENH: Add method to build a contour from user supplied polydata. This

is useful when you compute a bunch of points, lets say based on image features
and you want to display a contour widget that runs through those points.

Widgets/vtkOrientedGlyphContourRepresentation.cxx

@@ -40,7 +40,7 @@
 #include "vtkFocalPlanePointPlacer.h"
 #include "vtkBezierContourLineInterpolator.h"
 
-vtkCxxRevisionMacro(vtkOrientedGlyphContourRepresentation, "1.6");
+vtkCxxRevisionMacro(vtkOrientedGlyphContourRepresentation, "1.7");
 vtkStandardNewMacro(vtkOrientedGlyphContourRepresentation);
 
 //----------------------------------------------------------------------
@@ -607,6 +607,60 @@ void vtkOrientedGlyphContourRepresentation::BuildRepresentation()
 
 }
 
+//----------------------------------------------------------------------
+void vtkOrientedGlyphContourRepresentation
+::BuildRepresentationFromUserSuppliedPolydata( vtkPolyData * pd )
+{
+  vtkPoints *points   = pd->GetPoints();
+  vtkIdType nPoints = points->GetNumberOfPoints();
+  if (nPoints <= 0)
+    {
+    return; // Yeah right.. build from nothing !
+    }
+
+  // Clear all existing nodes.
+  for(unsigned int i=0;i<this->Internal->Nodes.size();i++)
+    {
+    for (unsigned int j=0;j<this->Internal->Nodes[i]->Points.size();j++)
+      {
+      delete this->Internal->Nodes[i]->Points[j];
+      }
+    this->Internal->Nodes[i]->Points.clear();
+    delete this->Internal->Nodes[i];
+    }
+  this->Internal->Nodes.clear();
+
+  vtkIdType index = 0;
+  vtkIdList *pointIds = pd->GetCell(0)->GetPointIds();
+
+  // Get the worldOrient from the point placer
+  double ref[3], displayPos[2], worldPos[3], worldOrient[9];
+  ref[0] = 0.0; ref[1] = 0.0; ref[2] = 0.0;
+  displayPos[0] = 0.0; displayPos[1] = 0.0;
+  this->PointPlacer->ComputeWorldPosition(this->Renderer,
+                                 displayPos, ref, worldPos, worldOrient );
+
+  // Add nodes
+
+  for ( vtkIdType i=0; i < nPoints; i++ )
+    {
+    double *p = points->GetPoint( i );
+    this->AddNodeAtWorldPosition( p, worldOrient );
+    }
+
+  if ( pointIds->GetNumberOfIds() > nPoints )
+    {
+    this->ClosedLoopOn();
+    }
+
+  // Update the contour representation from the nodes using the line interpolator
+  this->BuildRepresentation();
+
+  // Show the contour.
+  this->VisibilityOn();
+}
+
+
 //----------------------------------------------------------------------
 void vtkOrientedGlyphContourRepresentation::GetActors(vtkPropCollection *pc)
 {

Widgets/vtkOrientedGlyphContourRepresentation.h

@@ -82,6 +82,13 @@ public:
   virtual void WidgetInteraction(double eventPos[2]);
   virtual int ComputeInteractionState(int X, int Y, int modified=0);
 
+  // Description:
+  // Build a contour representation from externally supplied PolyData. This
+  // is very useful when you use an external program to compute a set of
+  // contour nodes, let's say based on image features. Subsequently, you want
+  // to build and display a contour that runs through those points.
+  virtual void BuildRepresentationFromUserSuppliedPolydata( vtkPolyData * );
+
   // Description:
   // Methods to make this class behave as a vtkProp.
   virtual void GetActors(vtkPropCollection *);