# RegularPolygonSource

VTKExamples/Cxx/GeometricObjects/RegularPolygonSource

### Description

This example creates a pentagon.

### Code

RegularPolygonSource.cxx

    #include <vtkSmartPointer.h>
    #include <vtkRegularPolygonSource.h>

    #include <vtkShrinkPolyData.h>
    #include <vtkProperty.h>
    #include <vtkPolyData.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkActor.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkNamedColors.h>

    int main(int , char *[])
    {
      vtkSmartPointer<vtkNamedColors> colors =
        vtkSmartPointer<vtkNamedColors>::New();

      // Create a pentagon
      vtkSmartPointer<vtkRegularPolygonSource> polygonSource =
        vtkSmartPointer<vtkRegularPolygonSource>::New();
      polygonSource->SetNumberOfSides(5);
      polygonSource->SetRadius(5);
      polygonSource->SetCenter(0,0,0);

      vtkSmartPointer<vtkShrinkPolyData> shrink =
        vtkSmartPointer<vtkShrinkPolyData>::New();
      shrink->SetInputConnection(polygonSource->GetOutputPort());
      shrink->SetShrinkFactor(.9);

      vtkSmartPointer<vtkPolyDataMapper> mapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      mapper->SetInputConnection(shrink->GetOutputPort());

      vtkSmartPointer<vtkProperty> back =
        vtkSmartPointer<vtkProperty>::New();
      back->SetColor(colors->GetColor3d("Tomato").GetData());

      vtkSmartPointer<vtkActor> actor =
        vtkSmartPointer<vtkActor>::New();
      actor->SetMapper(mapper);
      actor->GetProperty()->EdgeVisibilityOn();
      actor->GetProperty()->SetLineWidth(5);
      actor->GetProperty()->SetColor(colors->GetColor3d("Banana").GetData());
      actor->SetBackfaceProperty(back);

      vtkSmartPointer<vtkRenderer> renderer =
        vtkSmartPointer<vtkRenderer>::New();
      vtkSmartPointer<vtkRenderWindow> renderWindow =
        vtkSmartPointer<vtkRenderWindow>::New();
      renderWindow->AddRenderer(renderer);
      vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      renderWindowInteractor->SetRenderWindow(renderWindow);

      renderer->AddActor(actor);
      renderer->SetBackground(colors->GetColor3d("Silver").GetData());

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

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(RegularPolygonSource)

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

    add_executable(RegularPolygonSource MACOSX_BUNDLE RegularPolygonSource.cxx )

    target_link_libraries(RegularPolygonSource ${VTK_LIBRARIES})

### Download and Build RegularPolygonSource

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

    cd RegularPolygonSource/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:

    ./RegularPolygonSource

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.