text: #include <vtkDiscretizableColorTransferFunction.h>
  #include <vtkNew.h>
  
  int main(int, char*[])
  {
    vtkNew<vtkDiscretizableColorTransferFunction>
        discretizableColorTransferFunction;
  
    discretizableColorTransferFunction->DiscretizeOn();
    discretizableColorTransferFunction->SetNumberOfValues(2);
  
    discretizableColorTransferFunction->AddRGBPoint(0.0, 1, 0, 0);
    discretizableColorTransferFunction->AddRGBPoint(10.0, 0, 1, 0);
    discretizableColorTransferFunction->Build();
  
    double color[3];
    discretizableColorTransferFunction->GetColor(1.0, color);
    std::cout << color[0] << " " << color[1] << " " << color[2] << std::endl;
  
    discretizableColorTransferFunction->GetColor(5.0, color);
    std::cout << color[0] << " " << color[1] << " " << color[2] << std::endl;
  
    return EXIT_SUCCESS;
  }
  