# PieChart

VTKExamples/Cxx/Plotting/PieChart

### Code

PieChart.cxx

    #include <vtkRenderer.h>
    #include <vtkRenderWindow.h>
    #include <vtkSmartPointer.h>
    #include <vtkChartPie.h>
    #include <vtkPlot.h>
    #include <vtkPlotPie.h>
    #include <vtkTable.h>
    #include <vtkIntArray.h>
    #include <vtkStringArray.h>
    #include <vtkContextView.h>
    #include <vtkContextScene.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkColorSeries.h>

    int NUM_ITEMS = 5;
    static int data[] = {77938,9109,2070,12806,19514};
    //static int data[] = {200,200,200,200,200};
    static const char *labels[] = {"Books","New and Popular","Periodical","Audiobook","Video"};

    int main(int, char*[])
    {
      // Set up a 2D scene, add an XY chart to it
      vtkSmartPointer<vtkContextView> view =
        vtkSmartPointer<vtkContextView>::New();
      view->GetRenderer()->SetBackground(1.0, 1.0, 1.0);
      view->GetRenderWindow()->SetSize(600, 350);
      vtkSmartPointer<vtkChartPie> chart =
        vtkSmartPointer<vtkChartPie>::New();
      view->GetScene()->AddItem(chart);

      // Create a table with some points in it...
      vtkSmartPointer<vtkTable> table =
        vtkSmartPointer<vtkTable>::New();

      vtkSmartPointer<vtkIntArray> arrData =
        vtkSmartPointer<vtkIntArray>::New();
      vtkSmartPointer<vtkStringArray> labelArray =
        vtkSmartPointer<vtkStringArray>::New();

      arrData->SetName("2008 Circulation");
      for (int i = 0; i < NUM_ITEMS; i++)
      {
        arrData->InsertNextValue(data[i]);
        labelArray->InsertNextValue(labels[i]);
      }

      table->AddColumn(arrData);

      // Create a color series to use with our stacks.
      vtkSmartPointer<vtkColorSeries> colorSeries =
        vtkSmartPointer<vtkColorSeries>::New();
      colorSeries->SetColorScheme(vtkColorSeries::WARM);

      // Add multiple line plots, setting the colors etc
      vtkPlotPie *pie = vtkPlotPie::SafeDownCast(chart->AddPlot(0));
      pie->SetColorSeries(colorSeries);
      pie->SetInputData(table);
      pie->SetInputArray(0,"2008 Circulation");
      pie->SetLabels(labelArray);

      chart->SetShowLegend(true);

      chart->SetTitle("Circulation 2008");

      //Finally render the scene and compare the image to a reference image
      view->GetRenderWindow()->SetMultiSamples(0);
      view->GetRenderWindow()->Render();
      view->GetInteractor()->Initialize();
      view->GetInteractor()->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

    project(PieChart)

    find_package(VTK COMPONENTS
      vtkChartsCore
      vtkCommonColor
      vtkCommonCore
      vtkCommonDataModel
      vtkInteractionStyle
      vtkRenderingContext2D
      vtkRenderingContextOpenGL2
      vtkRenderingCore
      vtkRenderingFreeType
      vtkRenderingGL2PSOpenGL2
      vtkRenderingOpenGL2
      vtkViewsContext2D QUIET)
    if (NOT VTK_FOUND)
      message("Skipping PieChart: ${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(PieChart MACOSX_BUNDLE PieChart.cxx )
      target_link_libraries(PieChart PRIVATE ${VTK_LIBRARIES})
    else ()
      # include all components
      add_executable(PieChart MACOSX_BUNDLE PieChart.cxx )
      target_link_libraries(PieChart PRIVATE ${VTK_LIBRARIES})
      # vtk_module_autoinit is needed
      vtk_module_autoinit(
        TARGETS PieChart
        MODULES ${VTK_LIBRARIES}
        )
    endif ()

### Download and Build PieChart

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

    cd PieChart/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:

    ./PieChart

WINDOWS USERS

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