VTK/Examples/Cxx/Graphs/AdjacentVertexIterator

#include <vtkMutableUndirectedGraph.h>
#include <vtkSmartPointer.h>
#include <vtkAdjacentVertexIterator.h>
#include <vtkUnsignedCharArray.h>
#include <vtkLookupTable.h>
#include <vtkMutableDirectedGraph.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkViewTheme.h>
#include <vtkDataSetAttributes.h>
#include <vtkGraphLayoutView.h>
 
int main(int, char *[])
{
  vtkSmartPointer<vtkMutableUndirectedGraph> g = 
    vtkSmartPointer<vtkMutableUndirectedGraph>::New();
 
  //create 3 vertices
  vtkIdType v0 = g->AddVertex();
  vtkIdType v1 = g->AddVertex();
  vtkIdType v2 = g->AddVertex();
  vtkIdType v3 = g->AddVertex();
 
  //add edges
  g->AddEdge(v0, v1);
  g->AddEdge(v0, v2);
  g->AddEdge(v2, v3);
 
  // Create the color array
  vtkSmartPointer<vtkUnsignedCharArray> vertexColors = 
    vtkSmartPointer<vtkUnsignedCharArray>::New();
  vertexColors->SetNumberOfComponents(3);
  vertexColors->SetName("color");
 
  //setup colors
  unsigned char red[3] = {255, 0, 0};
  unsigned char green[3] = {0, 255, 0};
  unsigned char blue[3] = {0, 0, 255};
 
  for(unsigned int i = 0; i < 4; i++)
    {
    vertexColors->InsertNextTupleValue(blue);//not connected vertices
    }
 
 
  vtkSmartPointer<vtkAdjacentVertexIterator> iterator = 
    vtkSmartPointer<vtkAdjacentVertexIterator>::New();
  g->GetAdjacentVertices(0, iterator);
 
  vertexColors->SetTupleValue(0, red);//origin 
 
  while(iterator->HasNext())
    {
    vtkIdType nextVertex = iterator->Next();
    std::cout << "Next vertex: " << nextVertex << std::endl;
    vertexColors->SetTupleValue(nextVertex, green);//connected vertices
    }
 
  // Add the color array to the graph
  g->GetVertexData()->AddArray(vertexColors);
 
  vtkSmartPointer<vtkGraphLayoutView> graphLayoutView = 
    vtkSmartPointer<vtkGraphLayoutView>::New();
  graphLayoutView->AddRepresentationFromInput(g);
  graphLayoutView->SetLayoutStrategyToTree();
 
  graphLayoutView->SetVertexColorArrayName("color");
  graphLayoutView->ColorVerticesOn();
 
  vtkSmartPointer<vtkViewTheme> theme = 
    vtkSmartPointer<vtkViewTheme>::New();
  //theme->SetPointLookupTable(lookupTable);
  theme->ScalePointLookupTableOff();
  graphLayoutView->ApplyViewTheme(theme);
 
 
  graphLayoutView->ResetCamera();
  graphLayoutView->GetInteractor()->Initialize();
  graphLayoutView->GetInteractor()->Start();
 
  return EXIT_SUCCESS;
}