SeedWidgetImage

VTKExamples/Cxx/Widgets/SeedWidgetImage

Question

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Code

SeedWidgetImage.cxx

#include <vtkActor.h>
#include <vtkCommand.h>
#include <vtkImageActor.h>
#include <vtkImageCanvasSource2D.h>
#include <vtkInteractorStyleImage.h>
#include <vtkPointHandleRepresentation2D.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty2D.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSeedRepresentation.h>
#include <vtkSeedWidget.h>
#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>

class vtkSeedImageCallback : public vtkCommand
{
public:
  static vtkSeedImageCallback* New()
  {
    return new vtkSeedImageCallback;
  }

  vtkSeedImageCallback() = default;

  virtual void Execute(vtkObject*, unsigned long event, void* calldata)
  {
    if (event == vtkCommand::PlacePointEvent)
    {
      std::cout << "Placing point..." << std::endl;
      std::cout << "There are now "
                << this->SeedRepresentation->GetNumberOfSeeds() << " seeds."
                << std::endl;
      for (unsigned int seedId = 0; static_cast<int>(seedId) <
           this->SeedRepresentation->GetNumberOfSeeds();
           seedId++)
      {
        double pos[3];
        this->SeedRepresentation->GetSeedDisplayPosition(seedId, pos);
        std::cout << "Seed " << seedId << " : (" << pos[0] << " " << pos[1]
                  << " " << pos[2] << ")" << std::endl;
      }
      return;
    }
    if (event == vtkCommand::InteractionEvent)
    {
      std::cout << "Interaction..." << std::endl;
      if (calldata)
      {
        double pos[3];
        this->SeedRepresentation->GetSeedDisplayPosition(0, pos);
        std::cout << "Moved to (" << pos[0] << " " << pos[1] << " " << pos[2]
                  << ")" << std::endl;
      }
      return;
    }
  }

  void SetRepresentation(vtkSmartPointer<vtkSeedRepresentation> rep)
  {
    this->SeedRepresentation = rep;
  }
  void SetWidget(vtkSmartPointer<vtkSeedWidget> widget)
  {
    this->SeedWidget = widget;
  }

private:
  vtkSeedRepresentation* SeedRepresentation = nullptr;
  vtkSeedWidget* SeedWidget = nullptr;
};

int main(int /* argc */, char* /* argv */[])
{
  // Create an image
  auto drawing =
    vtkSmartPointer<vtkImageCanvasSource2D>::New();
  drawing->SetScalarTypeToUnsignedChar();
  drawing->SetNumberOfScalarComponents(3);
  drawing->SetExtent(0, 20, 0, 50, 0, 0);
  // Make a blue background
  drawing->SetDrawColor(0, 0, 255);
  drawing->FillBox(0, 20, 0, 50);
  // Make a red circle
  drawing->SetDrawColor(255, 0, 0, 0);
  drawing->DrawCircle(9, 10, 5);
  drawing->Update();

  auto imageActor =
    vtkSmartPointer<vtkImageActor>::New();
  imageActor->SetInputData(drawing->GetOutput());

  // Create a renderer and render window
  auto renderer =
    vtkSmartPointer<vtkRenderer>::New();
  renderer->AddActor(imageActor);
  auto renderWindow =
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->AddRenderer(renderer);

  // An interactor
  auto renderWindowInteractor =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  renderWindowInteractor->SetRenderWindow(renderWindow);

  // Setup interactor style
  auto interactorStyleImage =
    vtkSmartPointer<vtkInteractorStyleImage>::New();
  renderWindowInteractor->SetInteractorStyle(interactorStyleImage);

  // Create the representation
  auto handle =
    vtkSmartPointer<vtkPointHandleRepresentation2D>::New();
  handle->GetProperty()->SetColor(1, 0, 0);
  auto rep =
    vtkSmartPointer<vtkSeedRepresentation>::New();
  rep->SetHandleRepresentation(handle);

  // Seed widget
  auto seedWidget =
    vtkSmartPointer<vtkSeedWidget>::New();
  seedWidget->SetInteractor(renderWindowInteractor);
  seedWidget->SetRepresentation(rep);

  auto seedCallback =
    vtkSmartPointer<vtkSeedImageCallback>::New();
  seedCallback->SetRepresentation(rep);
  seedCallback->SetWidget(seedWidget);
  seedWidget->AddObserver(vtkCommand::PlacePointEvent, seedCallback);
  seedWidget->AddObserver(vtkCommand::InteractionEvent, seedCallback);

  renderWindow->Render();

  renderWindowInteractor->Initialize();
  renderWindow->Render();
  seedWidget->On();

  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(SeedWidgetImage)

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

Download and Build SeedWidgetImage

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

cd SeedWidgetImage/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:

./SeedWidgetImage

WINDOWS USERS

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