CommandSubclass

VTKExamples/Cxx/Utilities/CommandSubclass


Code

CommandSubclass.cxx

#include <vtkSmartPointer.h>
#include <vtkObjectFactory.h>
#include <vtkSphereSource.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkCommand.h>

class CommandSubclass2 : public vtkCommand
{
  public:
    vtkTypeMacro(CommandSubclass2, vtkCommand);

    static CommandSubclass2 *New()
    {
      return new CommandSubclass2;
    }

    void Execute(vtkObject *vtkNotUsed(caller), unsigned long vtkNotUsed(eventId), 
                        void *vtkNotUsed(callData))
    {
      std::cout << "timer callback" << std::endl;
    }

};

int main(int, char *[])
{
  // Create a sphere
  vtkSmartPointer<vtkSphereSource> sphereSource = 
    vtkSmartPointer<vtkSphereSource>::New();
  sphereSource->Update();

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

  // Initialize must be called prior to creating timer events.
  renderWindowInteractor->Initialize();
  renderWindowInteractor->CreateRepeatingTimer(500);

  vtkSmartPointer<CommandSubclass2> timerCallback = 
    vtkSmartPointer<CommandSubclass2>::New();
  renderWindowInteractor->AddObserver ( vtkCommand::TimerEvent, timerCallback );

  // Add the actor to the scene
  renderer->AddActor(actor);
  renderer->SetBackground(1,1,1); // Background color white

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

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(CommandSubclass)

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

Download and Build CommandSubclass

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

cd CommandSubclass/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:

./CommandSubclass

WINDOWS USERS

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