# vtkTestGraphAlgorithmFilter

VTKExamples/Cxx/Developers/vtkTestGraphAlgorithmFilter

### Code

vtkTestGraphAlgorithmFilter.cxx

    #include "vtkTestGraphAlgorithmFilter.h"

    #include "vtkObjectFactory.h"
    #include "vtkStreamingDemandDrivenPipeline.h"
    #include "vtkInformationVector.h"
    #include "vtkInformation.h"
    #include "vtkDataObject.h"
    #include "vtkSmartPointer.h"
    #include "vtkMutableUndirectedGraph.h"
    #include "vtkMutableDirectedGraph.h"
    #include "vtkMutableGraphHelper.h"

    vtkStandardNewMacro(vtkTestGraphAlgorithmFilter);

    int vtkTestGraphAlgorithmFilter::RequestData(vtkInformation *vtkNotUsed(request),
                                                 vtkInformationVector **inputVector,
                                                 vtkInformationVector *outputVector)
    {

      // get the info objects
      vtkInformation *inInfo = inputVector[0]->GetInformationObject(0);
      vtkInformation *outInfo = outputVector->GetInformationObject(0);

      // get the input and ouptut
      vtkGraph *input = vtkGraph::SafeDownCast(
          inInfo->Get(vtkDataObject::DATA_OBJECT()));

      vtkGraph *output = vtkGraph::SafeDownCast(
                                        outInfo->Get(vtkDataObject::DATA_OBJECT()));

      vtkSmartPointer<vtkMutableDirectedGraph> mdg =
        vtkSmartPointer<vtkMutableDirectedGraph>::New();

      vtkSmartPointer<vtkMutableUndirectedGraph> mug =
        vtkSmartPointer<vtkMutableUndirectedGraph>::New();

      if(input->IsA("vtkMutableUndirectedGraph"))
      {
        vtkSmartPointer<vtkMutableUndirectedGraph> ug =
          vtkSmartPointer<vtkMutableUndirectedGraph>::New();
        ug->AddVertex();
        output->ShallowCopy(ug);
      }
      else if(input->IsA("vtkMutableDirectedGraph"))
      {
        vtkSmartPointer<vtkMutableDirectedGraph> dg =
          vtkSmartPointer<vtkMutableDirectedGraph>::New();
        dg->AddVertex();
        output->ShallowCopy(dg);
      }

      std::cout << "Output is type: " << output->GetClassName() << std::endl;

      return 1;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(vtkTestGraphAlgorithmFilter)

    find_package(VTK REQUIRED)
    include(${VTK_USE_FILE})

    add_executable(vtkTestGraphAlgorithmFilter MACOSX_BUNDLE vtkTestGraphAlgorithmFilter.cxx)

    target_link_libraries(vtkTestGraphAlgorithmFilter ${VTK_LIBRARIES})

### Download and Build vtkTestGraphAlgorithmFilter

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

    cd vtkTestGraphAlgorithmFilter/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:

    ./vtkTestGraphAlgorithmFilter

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