Method UpdateRepresentation

Rendering/VR/vtkVRControlsHelper.cxx:123–272

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//------------------------------------------------------------------------------
void vtkVRControlsHelper::UpdateRepresentation()
{
  this->NeedUpdate = false;
  if (!this->Enabled)
  {
    return;
  }

  if (this->Renderer && this->Renderer->GetRenderWindow() &&
    this->Renderer->GetRenderWindow()->GetInteractor())
  {
    vtkVRRenderWindow* renWin = static_cast<vtkVRRenderWindow*>(this->Renderer->GetRenderWindow());
    if (!renWin)
    {
      return;
    }

    // Update physical scale
    double physicalScale = renWin->GetPhysicalScale();

    // Get the active controller device
    vtkEventDataDevice controller = this->Device;

    // Hide controls tooltips if the controller is off
    vtkVRModel* mod = renWin->GetModelForDevice(controller);
    if (!mod)
    {
      this->LabelVisible = false;
      return;
    }

    // Get the controls offset position in the controller local coordinate system
    if (this->ControlPositionLC[0] == 0. && this->ControlPositionLC[1] == 0. &&
      this->ControlPositionLC[2] == 0.)
    {
      this->InitControlPosition();
    }

    // Controller position and world orientation
    double* ptrans = renWin->GetPhysicalTranslation();
    this->LastEventPosition[0] += this->LastPhysicalTranslation[0] - ptrans[0];
    this->LastEventPosition[1] += this->LastPhysicalTranslation[1] - ptrans[1];
    this->LastEventPosition[2] += this->LastPhysicalTranslation[2] - ptrans[2];
    const double* controllerPositionWC = this->LastEventPosition;
    const double* wxyz = this->LastEventOrientation;

    // todo use ivar here
    this->TempTransform->Identity();
    this->TempTransform->RotateWXYZ(wxyz[0], wxyz[1], wxyz[2], wxyz[3]);

    double* frameForward = this->Renderer->GetActiveCamera()->GetDirectionOfProjection();
    // Controller up direction in WC
    double* controllerUpWC = this->TempTransform->TransformDoubleVector(0.0, 1.0, 0.0);

    // Compute scale factor. It reaches its max value when the control button
    //  faces the camera. This results in tooltips popping from the controller.
    double dotFactor = -vtkMath::Dot(controllerUpWC, frameForward);