VTK/Examples/Cxx/Utilities/Timer

This example demonstrates how to use a timer with an interactor. It outputs a count every specified interval.

Timer.cxx

#include <vtkSmartPointer.h>
#include <vtkCommand.h>
#include <vtkRenderer.h>
#include <vtkRendererCollection.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>

class vtkTimerCallback : public vtkCommand
{
  public:
    static vtkTimerCallback *New()
    {
      vtkTimerCallback *cb = new vtkTimerCallback;
      cb->TimerCount = 0;
      return cb;
    }

    virtual void Execute(vtkObject *vtkNotUsed(caller), unsigned long eventId,
                         void *vtkNotUsed(callData))
    {
      if (vtkCommand::TimerEvent == eventId)
        {
        ++this->TimerCount;
        }
        cout << this->TimerCount << endl;
    }

  private:
    int TimerCount;
    
};

int main(int, char *[])
{
  // Setup renderer, render window, and interactor
  vtkSmartPointer<vtkRenderer> renderer = 
    vtkSmartPointer<vtkRenderer>::New();
  vtkSmartPointer<vtkRenderWindow> renderWindow = 
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->AddRenderer(renderer);
  vtkSmartPointer<vtkRenderWindowInteractor> interactor = 
      vtkSmartPointer<vtkRenderWindowInteractor>::New();
  interactor->SetRenderWindow(renderWindow);

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

  // Sign up to receive TimerEvent
  vtkSmartPointer<vtkTimerCallback> cb = 
    vtkSmartPointer<vtkTimerCallback>::New();
  interactor->AddObserver(vtkCommand::TimerEvent, cb);
  
  int timerId = interactor->CreateRepeatingTimer(100);
  std::cout << "timerId: " << timerId << std::endl;  

  // Start the interaction and timer
  interactor->Start();

  return EXIT_SUCCESS;
}

Please try the new VTKExamples website.

CMakeLists.txt

cmake_minimum_required(VERSION 2.8)

PROJECT(Timer)

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

add_executable(Timer MACOSX_BUNDLE Timer.cxx)

if(VTK_LIBRARIES)
  target_link_libraries(Timer ${VTK_LIBRARIES})
else()
  target_link_libraries(Timer vtkHybrid vtkWidgets)
endif()

Download and Build Timer

Click here to download Timer. and its CMakeLists.txt file.

Once the tarball Timer.tar has been downloaded and extracted,

cd Timer/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:

./Timer

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.

Maybe display the count using a vtkTextActor?