# ProgrammableGlyphFilter

VTKExamples/Cxx/Visualization/ProgrammableGlyphFilter

### Code

ProgrammableGlyphFilter.cxx

    #include <vtkSmartPointer.h>
    #include <vtkPointData.h>
    #include <vtkCubeSource.h>
    #include <vtkConeSource.h>
    #include <vtkSphereSource.h>
    #include <vtkPolyData.h>
    #include <vtkPoints.h>
    #include <vtkProgrammableGlyphFilter.h>
    #include <vtkCellArray.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkActor.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkFloatArray.h>

    void CalcGlyph(void *arg)
    {

      vtkProgrammableGlyphFilter *glyphFilter = (vtkProgrammableGlyphFilter*) arg;

      if(!glyphFilter)
      {
        std::cerr << "glyphFilter is not valid!" << std::endl;
      }
      double pointCoords[3];
      glyphFilter->GetPoint(pointCoords);

      std::cout << "Calling CalcGlyph for point "
                << glyphFilter->GetPointId() << std::endl;
      std::cout << "Point coords are: "
                << pointCoords[0] << " "
                << pointCoords[1] << " "
                << pointCoords[2] << std::endl;
      if(glyphFilter->GetPointId() == 0)
      {
        vtkSmartPointer<vtkConeSource> coneSource =
          vtkSmartPointer<vtkConeSource>::New();
        coneSource->SetCenter(pointCoords);
        glyphFilter->SetSourceConnection(coneSource->GetOutputPort());
      }
      else if(glyphFilter->GetPointId() == 1)
      {
        vtkSmartPointer<vtkCubeSource> cubeSource =
          vtkSmartPointer<vtkCubeSource>::New();
        cubeSource->SetCenter(pointCoords);
        glyphFilter->SetSourceConnection(cubeSource->GetOutputPort());
      }
      else if(glyphFilter->GetPointId() == 2)
      {
        vtkSmartPointer<vtkSphereSource> sphereSource =
          vtkSmartPointer<vtkSphereSource>::New();
        sphereSource->SetCenter(pointCoords);
        glyphFilter->SetSourceConnection(sphereSource->GetOutputPort());
      }
    }

    int main(int, char *[])
    {
      // Create points
      vtkSmartPointer<vtkPoints> points =
        vtkSmartPointer<vtkPoints>::New();
      points->InsertNextPoint(0,0,0);
      points->InsertNextPoint(5,0,0);
      points->InsertNextPoint(10,0,0);

      // Combine into a polydata
      vtkSmartPointer<vtkPolyData> polydata =
        vtkSmartPointer<vtkPolyData>::New();
      polydata->SetPoints(points);

      vtkSmartPointer<vtkProgrammableGlyphFilter> glyphFilter =
        vtkSmartPointer<vtkProgrammableGlyphFilter>::New();
      glyphFilter->SetInputData(polydata);
      glyphFilter->SetGlyphMethod(CalcGlyph, glyphFilter);
      //need a default glyph, but this should not be used
      vtkSmartPointer<vtkConeSource> coneSource =
        vtkSmartPointer<vtkConeSource>::New();
      glyphFilter->SetSourceConnection(coneSource->GetOutputPort());

      // Create a mapper and actor
      vtkSmartPointer<vtkPolyDataMapper> mapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      mapper->SetInputConnection(glyphFilter->GetOutputPort());
      vtkSmartPointer<vtkActor> actor =
        vtkSmartPointer<vtkActor>::New();
      actor->SetMapper(mapper);

      // Create a renderer, render window, and interactor
      vtkSmartPointer<vtkRenderer> renderer =
        vtkSmartPointer<vtkRenderer>::New();
      vtkSmartPointer<vtkRenderWindow> renderWindow =
        vtkSmartPointer<vtkRenderWindow>::New();
      renderWindow->AddRenderer(renderer);
      vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      renderWindowInteractor->SetRenderWindow(renderWindow);

      // Add the actor to the scene
      renderer->AddActor(actor);
      renderer->SetBackground(.2, .3, .4);

      // Render and interact
      renderWindow->Render();
      renderWindowInteractor->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

    project(ProgrammableGlyphFilter)

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

### Download and Build ProgrammableGlyphFilter

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

    cd ProgrammableGlyphFilter/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:

    ./ProgrammableGlyphFilter

WINDOWS USERS

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