# CreateBFont

VTKExamples/Cxx/VisualizationAlgorithms/CreateBFont

### Description

A scanned image clipped with a scalar value of 1/2 its maximum intensity produces a mixture of quadrilaterals and triangles.

Info

See Figure 9-10 in Chapter 9 The VTK Textbook.

Other Languages

See (Python)

### Code

CreateBFont.cxx

    #include <vtkActor.h>
    #include <vtkCamera.h>
    #include <vtkClipPolyData.h>
    #include <vtkImageDataGeometryFilter.h>
    #include <vtkImageGaussianSmooth.h>
    #include <vtkNamedColors.h>
    #include <vtkPNMReader.h>
    #include <vtkPointData.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkProperty.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkRenderer.h>

    int main (int argc, char *argv[])
    {
      if (argc < 2)
      {
        std::cout << "Usage: " << argv[0] << " image.pgm" << std::endl;
        return EXIT_FAILURE;
      }
    // Now create the RenderWindow, Renderer and Interactor
    //
      vtkSmartPointer<vtkNamedColors> colors =
        vtkSmartPointer<vtkNamedColors>::New();

      vtkSmartPointer<vtkRenderer> ren1 =
        vtkSmartPointer<vtkRenderer>::New();

      vtkSmartPointer<vtkRenderWindow> renWin =
        vtkSmartPointer<vtkRenderWindow>::New();
      renWin->AddRenderer(ren1);

      vtkSmartPointer<vtkRenderWindowInteractor> iren =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      iren->SetRenderWindow(renWin);

      vtkSmartPointer<vtkPNMReader> imageIn =
        vtkSmartPointer<vtkPNMReader>::New();
      imageIn->SetFileName(argv[1]);

      vtkSmartPointer<vtkImageGaussianSmooth> gaussian =
        vtkSmartPointer<vtkImageGaussianSmooth>::New();
      gaussian->SetStandardDeviations(2, 2);
      gaussian->SetDimensionality(2);
      gaussian->SetRadiusFactors(1, 1);
      gaussian->SetInputConnection(imageIn->GetOutputPort());

      vtkSmartPointer<vtkImageDataGeometryFilter> geometry =
        vtkSmartPointer<vtkImageDataGeometryFilter>::New();
      geometry->SetInputConnection(gaussian->GetOutputPort());

      vtkSmartPointer<vtkClipPolyData> aClipper =
      vtkSmartPointer<vtkClipPolyData>::New();
      aClipper->SetInputConnection(geometry->GetOutputPort());
      aClipper->SetValue(127.5);
      aClipper->GenerateClipScalarsOff();
      aClipper->InsideOutOn();
      aClipper->GetOutput()->GetPointData()->CopyScalarsOff();
      aClipper->Update();

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

      vtkSmartPointer<vtkActor> letter =
        vtkSmartPointer<vtkActor>::New();
      letter->SetMapper(mapper);

      ren1->AddActor(letter);
      letter->GetProperty()->SetDiffuseColor(colors->GetColor3d("LampBlack").GetData());
      letter->GetProperty()->SetRepresentationToWireframe();

      ren1->SetBackground(colors->GetColor3d("WhiteSmoke").GetData());
      ren1->ResetCamera();
      ren1->GetActiveCamera()->Dolly(1.2);
      ren1->ResetCameraClippingRange();

      renWin->SetSize(640, 480);

    // render the image
    //
      renWin->Render();
      iren->Start();
      return EXIT_SUCCESS;
      }

### CMakeLists.txt

    cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

    project(CreateBFont)

    find_package(VTK COMPONENTS
      vtkCommonColor
      vtkCommonDataModel
      vtkFiltersCore
      vtkFiltersGeometry
      vtkIOImage
      vtkImagingGeneral
      vtkInteractionStyle
      vtkRenderingCore
      vtkRenderingFreeType
      vtkRenderingOpenGL2 QUIET)
    if (NOT VTK_FOUND)
      message("Skipping CreateBFont: ${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(CreateBFont MACOSX_BUNDLE CreateBFont.cxx )
      target_link_libraries(CreateBFont PRIVATE ${VTK_LIBRARIES})
    else ()
      # include all components
      add_executable(CreateBFont MACOSX_BUNDLE CreateBFont.cxx )
      target_link_libraries(CreateBFont PRIVATE ${VTK_LIBRARIES})
      # vtk_module_autoinit is needed
      vtk_module_autoinit(
        TARGETS CreateBFont
        MODULES ${VTK_LIBRARIES}
        )
    endif ()

### Download and Build CreateBFont

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

    cd CreateBFont/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:

    ./CreateBFont

WINDOWS USERS

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