# Triangulate

VTKExamples/Cxx/Meshes/Triangulate

### Code

Triangulate.cxx

    #include <vtkSmartPointer.h>
    #include <vtkProperty.h>
    #include <vtkPolyData.h>
    #include <vtkTriangleFilter.h>
    #include <vtkRegularPolygonSource.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkActor.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindowInteractor.h>

    int main(int, char *[])
    {
      vtkSmartPointer<vtkRegularPolygonSource> polygonSource =
        vtkSmartPointer<vtkRegularPolygonSource>::New();
      polygonSource->Update();

      vtkSmartPointer<vtkTriangleFilter> triangleFilter =
        vtkSmartPointer<vtkTriangleFilter>::New();
      triangleFilter->SetInputConnection(polygonSource->GetOutputPort());
      triangleFilter->Update();

      vtkSmartPointer<vtkPolyDataMapper> inputMapper =
          vtkSmartPointer<vtkPolyDataMapper>::New();
      inputMapper->SetInputConnection(polygonSource->GetOutputPort());
      vtkSmartPointer<vtkActor> inputActor =
          vtkSmartPointer<vtkActor>::New();
      inputActor->SetMapper(inputMapper);
      inputActor->GetProperty()->SetRepresentationToWireframe();

      vtkSmartPointer<vtkPolyDataMapper> triangleMapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      triangleMapper->SetInputConnection(triangleFilter->GetOutputPort());
      vtkSmartPointer<vtkActor> triangleActor =
          vtkSmartPointer<vtkActor>::New();
      triangleActor->SetMapper(triangleMapper);
      triangleActor->GetProperty()->SetRepresentationToWireframe();

      // There will be one render window
      vtkSmartPointer<vtkRenderWindow> renderWindow =
        vtkSmartPointer<vtkRenderWindow>::New();
      renderWindow->SetSize(600, 300);

      // And one interactor
      vtkSmartPointer<vtkRenderWindowInteractor> interactor =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      interactor->SetRenderWindow(renderWindow);

      // Define viewport ranges
      // (xmin, ymin, xmax, ymax)
      double leftViewport[4] = {0.0, 0.0, 0.5, 1.0};
      double rightViewport[4] = {0.5, 0.0, 1.0, 1.0};

      // Setup both renderers
      vtkSmartPointer<vtkRenderer> leftRenderer =
        vtkSmartPointer<vtkRenderer>::New();
      renderWindow->AddRenderer(leftRenderer);
      leftRenderer->SetViewport(leftViewport);
      leftRenderer->SetBackground(.6, .5, .4);

      vtkSmartPointer<vtkRenderer> rightRenderer =
        vtkSmartPointer<vtkRenderer>::New();
      renderWindow->AddRenderer(rightRenderer);
      rightRenderer->SetViewport(rightViewport);
      rightRenderer->SetBackground(.4, .5, .6);

      leftRenderer->AddActor(inputActor);
      rightRenderer->AddActor(triangleActor);

      leftRenderer->ResetCamera();

      rightRenderer->ResetCamera();

      renderWindow->Render();
      interactor->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(Triangulate)

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

    add_executable(Triangulate MACOSX_BUNDLE Triangulate.cxx )

    target_link_libraries(Triangulate ${VTK_LIBRARIES})

### Download and Build Triangulate

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

    cd Triangulate/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:

    ./Triangulate

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.