# MoveAGlyph

VTKExamples/Cxx/Interaction/MoveAGlyph

### Description

This example allows the user to reposition a glyph. It does this by faking the interactor into thinking that a new actor (MoveActor) is the object to be interacted with. We use the array generated by glyph3D->GeneratePointIdsOn() to determine the point associated with the glyph that the user selected. A "ghost" actor of the selected glyph is generated (because all of the glyphs are part of the same actor, so they would all move together). This actor is moved, and its final position is used to update the point in the original data set.

### Code

MoveAGlyph.cxx

    #include <vtkVersion.h>
    #include <vtkSmartPointer.h>
    #include <vtkCellPicker.h>
    #include <vtkSphereSource.h>
    #include <vtkGlyph3D.h>
    #include <vtkPointData.h>
    #include <vtkIdTypeArray.h>
    #include <vtkDataSetSurfaceFilter.h>
    #include <vtkRendererCollection.h>
    #include <vtkProperty.h>
    #include <vtkPlanes.h>
    #include <vtkObjectFactory.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkActor.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkPolyData.h>
    #include <vtkPointSource.h>
    #include <vtkInteractorStyleTrackballActor.h>
    #include <vtkAreaPicker.h>
    #include <vtkExtractGeometry.h>
    #include <vtkDataSetMapper.h>
    #include <vtkUnstructuredGrid.h>
    #include <vtkVertexGlyphFilter.h>
    #include <vtkIdFilter.h>

    // Define interaction style
    class InteractorStyleMoveGlyph : public vtkInteractorStyleTrackballActor
    {
      public:
        static InteractorStyleMoveGlyph* New();
        vtkTypeMacro(InteractorStyleMoveGlyph,vtkInteractorStyleTrackballActor);

        InteractorStyleMoveGlyph()
        {
          this->MoveSphereSource = vtkSmartPointer<vtkSphereSource>::New();
          this->MoveSphereSource->SetRadius(.1);
          this->MoveSphereSource->Update();

          this->MoveMapper = vtkSmartPointer<vtkPolyDataMapper>::New();
          this->MoveMapper->SetInputConnection(this->MoveSphereSource->GetOutputPort());

          this->MoveActor = vtkSmartPointer<vtkActor>::New();
          this->MoveActor->SetMapper(this->MoveMapper);
          //this->MoveActor->VisibilityOff();

          this->Move = false;
        }

        void OnMouseMove()
        {
          if(!this->Move)
          {
            return;
          }

          vtkInteractorStyleTrackballActor::OnMouseMove();

        }

        void OnMiddleButtonUp()
        {
          // Forward events
          vtkInteractorStyleTrackballActor::OnMiddleButtonUp();
          this->Move = false;
          this->MoveActor->VisibilityOff();

          this->Data->GetPoints()->SetPoint(this->SelectedPoint, this->MoveActor->GetPosition());
          this->Data->Modified();
          this->GetCurrentRenderer()->Render();
          this->GetCurrentRenderer()->GetRenderWindow()->Render();

        }
        void OnMiddleButtonDown()
        {
          // Forward events
          vtkInteractorStyleTrackballActor::OnMiddleButtonDown();
          this->MoveActor->VisibilityOn();
          if(static_cast<vtkCellPicker*>(this->InteractionPicker)->GetPointId() >= 0)
          {
            vtkIdType id = vtkIdTypeArray::SafeDownCast(this->GlyphData->GetPointData()->GetArray("InputPointIds"))
                        ->GetValue(static_cast<vtkCellPicker*>(this->InteractionPicker)->GetPointId());
            std::cout << "Id: " << id << std::endl;
            this->Move = true;
            this->SelectedPoint = id;

            double p[3];
            this->Data->GetPoint(id, p);
            std::cout << "p: " << p[0] << " " << p[1] << " " << p[2] << std::endl;
            this->MoveActor->SetPosition(p);
          }

          this->GetCurrentRenderer()->AddActor(this->MoveActor);
          this->InteractionProp = this->MoveActor;

        }
      vtkPolyData* Data;
      vtkPolyData* GlyphData;

      vtkSmartPointer<vtkPolyDataMapper> MoveMapper;
      vtkSmartPointer<vtkActor> MoveActor;
      vtkSmartPointer<vtkSphereSource> MoveSphereSource;

      bool Move;
      vtkIdType SelectedPoint;
    };
    vtkStandardNewMacro(InteractorStyleMoveGlyph);

    int main (int, char *[])
    {
      vtkSmartPointer<vtkPoints> points =
        vtkSmartPointer<vtkPoints>::New();
      points->InsertNextPoint(0,0,0);
      points->InsertNextPoint(1,0,0);
      points->InsertNextPoint(2,0,0);

      vtkSmartPointer<vtkPolyData> input =
        vtkSmartPointer<vtkPolyData>::New();
      input->SetPoints(points);

      vtkSmartPointer<vtkSphereSource> glyphSource =
        vtkSmartPointer<vtkSphereSource>::New();
      glyphSource->SetRadius(.1);
      glyphSource->Update();

      vtkSmartPointer<vtkGlyph3D> glyph3D =
        vtkSmartPointer<vtkGlyph3D>::New();
      glyph3D->GeneratePointIdsOn();
      glyph3D->SetSourceConnection(glyphSource->GetOutputPort());
    #if VTK_MAJOR_VERSION <= 5
      glyph3D->SetInputConnection(input->GetProducerPort());
    #else
      glyph3D->SetInputData(input);
    #endif
      glyph3D->SetScaleModeToDataScalingOff();
      glyph3D->Update();

      // Create a mapper and actor
      vtkSmartPointer<vtkPolyDataMapper> mapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      mapper->SetInputConnection(glyph3D->GetOutputPort());

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

      // Visualize
      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(1,1,1); // Background color white

      renderWindow->Render();

      vtkSmartPointer<InteractorStyleMoveGlyph> style =
        vtkSmartPointer<InteractorStyleMoveGlyph>::New();
      renderWindowInteractor->SetInteractorStyle( style );
      style->Data = input;
      style->GlyphData = glyph3D->GetOutput();

      renderWindowInteractor->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(MoveAGlyph)

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

    add_executable(MoveAGlyph MACOSX_BUNDLE MoveAGlyph.cxx )

    target_link_libraries(MoveAGlyph ${VTK_LIBRARIES})

### Download and Build MoveAGlyph

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

    cd MoveAGlyph/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:

    ./MoveAGlyph

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.