Method AutoScale

Rendering/Annotation/vtkAxisFollower.cxx:172–206

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//------------------------------------------------------------------------------
double vtkAxisFollower::AutoScale(
  vtkViewport* viewport, vtkCamera* camera, double screenSize, double position[3])
{
  double newScale = 0.0;

  if (!viewport)
  {
    std::cerr << "Invalid or nullptr viewport \n";
    return newScale;
  }

  if (!camera)
  {
    std::cerr << "Invalid or nullptr camera \n";
    return newScale;
  }

  if (!position)
  {
    std::cerr << "Invalid or nullptr position \n";
    return newScale;
  }

  double factor = 1;
  if (viewport->GetSize()[1] > 0)
  {
    factor = 2.0 * screenSize * tan(vtkMath::RadiansFromDegrees(camera->GetViewAngle() / 2.0)) /
      viewport->GetSize()[1];
  }

  double dist = sqrt(vtkMath::Distance2BetweenPoints(position, camera->GetPosition()));
  newScale = factor * dist;

  return newScale;
}

//------------------------------------------------------------------------------
void vtkAxisFollower::ComputeTransformMatrix(vtkRenderer* ren)