DistanceWidget

#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkSmartPointer.h>
#include <vtkDistanceWidget.h>
#include <vtkDistanceRepresentation.h>

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

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

  vtkSmartPointer<vtkDistanceWidget> distanceWidget =
    vtkSmartPointer<vtkDistanceWidget>::New();
  distanceWidget->SetInteractor(renderWindowInteractor);
  distanceWidget->CreateDefaultRepresentation();
  static_cast<vtkDistanceRepresentation *>(distanceWidget->GetRepresentation())
    ->SetLabelFormat("%-#6.3g mm");

  // Render an image (lights and cameras are created automatically)
  renderWindow->Render();

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

  // Begin mouse interaction
  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(DistanceWidget)

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

cd DistanceWidget/build 

cmake ..

cmake -DVTK_DIR:PATH=/home/me/vtk_build ..

make

./DistanceWidget