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AdjacentVertexIterator

vtk-examples/Cxx/Graphs/AdjacentVertexIterator


Description

The visualization in this example is currently broken. vtkGraphLayoutView does not currently allow coloring with a vtkUnsignedCharArray.

Question

If you have a question about this example, please use the VTK Discourse Forum

Code

AdjacentVertexIterator.cxx

#include <vtkAdjacentVertexIterator.h>
#include <vtkDataSetAttributes.h>
#include <vtkGraphLayoutView.h>
#include <vtkLookupTable.h>
#include <vtkMutableUndirectedGraph.h>
#include <vtkMutableDirectedGraph.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkUnsignedCharArray.h>
#include <vtkViewTheme.h>


// For compatibility with new VTK generic data arrays
#ifdef vtkGenericDataArray_h
#define InsertNextTupleValue InsertNextTypedTuple
#endif

int main(int, char *[])
{
  vtkNew<vtkNamedColors> colors;

  vtkNew<vtkMutableUndirectedGraph> g;

  //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
  vtkNew<vtkUnsignedCharArray> vertexColors;
  vertexColors->SetNumberOfComponents(3);
  vertexColors->SetName("color");

  //setup colors
   vertexColors->InsertNextTypedTuple(
        colors->GetColor3ub("Blue").GetData()); // unconnected vertices

  vertexColors->InsertNextTypedTuple(colors->GetColor3ub("Red").GetData()); // origin

  vtkNew<vtkAdjacentVertexIterator> iterator;
  g->GetAdjacentVertices(0, iterator);

  while(iterator->HasNext())
  {
    vtkIdType nextVertex = iterator->Next();
    std::cout << "Next vertex: " << nextVertex << std::endl;
    vertexColors->InsertNextTypedTuple(
        colors->GetColor3ub("Green").GetData()); // connected vertices
  }

  // Add the color array to the graph
  g->GetVertexData()->AddArray(vertexColors);

  vtkNew<vtkGraphLayoutView> graphLayoutView;
  graphLayoutView->AddRepresentationFromInput(g);
  graphLayoutView->SetLayoutStrategyToTree();

  graphLayoutView->SetVertexColorArrayName("color");
  graphLayoutView->ColorVerticesOn();

  vtkNew<vtkViewTheme> theme;
  //theme->SetPointLookupTable(lookupTable);
  theme->ScalePointLookupTableOff();
  graphLayoutView->ApplyViewTheme(theme);


  graphLayoutView->ResetCamera();
  graphLayoutView->GetInteractor()->Initialize();
  graphLayoutView->GetInteractor()->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(AdjacentVertexIterator)

find_package(VTK COMPONENTS 
  vtkCommonColor
  vtkCommonCore
  vtkCommonDataModel
  vtkInteractionStyle
  vtkRenderingContextOpenGL2
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingGL2PSOpenGL2
  vtkRenderingOpenGL2
  vtkViewsCore
  vtkViewsInfovis
  QUIET
)

if (NOT VTK_FOUND)
  message("Skipping AdjacentVertexIterator: ${VTK_NOT_FOUND_MESSAGE}")
  return ()
endif()
message (STATUS "VTK_VERSION: ${VTK_VERSION}")
if (VTK_VERSION VERSION_LESS "8.90.0")
  # old system
  include(${VTK_USE_FILE})
  add_executable(AdjacentVertexIterator MACOSX_BUNDLE AdjacentVertexIterator.cxx )
  target_link_libraries(AdjacentVertexIterator PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(AdjacentVertexIterator MACOSX_BUNDLE AdjacentVertexIterator.cxx )
  target_link_libraries(AdjacentVertexIterator PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS AdjacentVertexIterator
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build AdjacentVertexIterator

Click here to download AdjacentVertexIterator and its CMakeLists.txt file. Once the tarball AdjacentVertexIterator.tar has been downloaded and extracted,

cd AdjacentVertexIterator/build

If VTK is installed:

cmake ..

If VTK is not installed but compiled on your system, you will need to specify the path to your VTK build:

cmake -DVTK_DIR:PATH=/home/me/vtk_build ..

Build the project:

make

and run it:

./AdjacentVertexIterator

WINDOWS USERS

Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.