Method WidgetInteraction

Interaction/Widgets/vtkMagnifierRepresentation.cxx:88–143

------------------------------------------------------------------------------ Move the magnifier around. This method is invoked every time the mouse moves.

// Move the magnifier around. This method is invoked every time the mouse
// moves.
void vtkMagnifierRepresentation::WidgetInteraction(double eventPos[2])
{
  int XF = eventPos[0];
  int YF = eventPos[1];

  // Make sure the renderer and render window have been defined
  vtkRenderWindow* renWin;
  if (!this->Renderer || !(renWin = this->Renderer->GetRenderWindow()))
  {
    return;
  }

  // If event outside of this window, turn off magnify renderer
  this->InsideRenderer = (this->Renderer->IsInViewport(XF, YF) != 0);

  // Build the representation as necessary
  this->BuildRepresentation();

  // Move the viewport /renderer to the current mouse position
  int* winSize = this->Renderer->GetRenderWindow()->GetSize();
  int* vpSize = this->Renderer->GetSize();
  double vpxMax = static_cast<double>(vpSize[0]) / winSize[0];
  double vpyMax = static_cast<double>(vpSize[1]) / winSize[1];
  double viewPort[4];
  viewPort[0] = eventPos[0] / winSize[0];
  viewPort[1] = eventPos[1] / winSize[1];
  viewPort[2] = viewPort[0] + static_cast<double>(this->Size[0]) / winSize[0];
  viewPort[3] = viewPort[1] + static_cast<double>(this->Size[1]) / winSize[1];
  viewPort[2] = ((viewPort[2] - viewPort[0]) > vpxMax ? vpxMax : viewPort[2]);
  viewPort[3] = ((viewPort[3] - viewPort[1]) > vpyMax ? vpyMax : viewPort[3]);

  this->MagnificationRenderer->SetViewport(viewPort);

  // Update the magnificationcamera
  // Grab the containing renderer's camera and copy it. Adjust the view angle
  vtkCamera* cam = this->Renderer->GetActiveCamera();
  double viewAngle = cam->GetViewAngle();
  vtkCamera* magCam = this->MagnificationRenderer->GetActiveCamera();
  magCam->DeepCopy(cam);
  magCam->SetViewAngle(viewAngle / this->MagnificationFactor);

  // Specify the focal point
  this->Coordinate->SetValue(XF, YF);
  double* focal = this->Coordinate->GetComputedWorldValue(this->Renderer);
  this->MagnificationRenderer->GetActiveCamera()->SetFocalPoint(focal);

  // Setup the border if requested. We offset the border slightly to
  // accommodate the width of the line.
  if (this->Border)
  {
    this->BorderPoints->SetPoint(0, 1, 1, 0.0);
    this->BorderPoints->SetPoint(1, (this->Size[0] - 1), 1, 0.0);
    this->BorderPoints->SetPoint(2, (this->Size[0] - 1), (this->Size[1] - 1), 0.0);
    this->BorderPoints->SetPoint(3, 1, (this->Size[1] - 1), 0.0);
  }
}

//------------------------------------------------------------------------------