Method RenderOverlay

Rendering/OpenGL2/vtkOpenGLPolyDataMapper2D.cxx:642–797

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//------------------------------------------------------------------------------
void vtkOpenGLPolyDataMapper2D::RenderOverlay(vtkViewport* viewport, vtkActor2D* actor)
{
  vtkOpenGLClearErrorMacro();
  vtkPolyData* input = this->GetInput();

  vtkDebugMacro(<< "vtkOpenGLPolyDataMapper2D::Render");

  if (input == nullptr)
  {
    vtkErrorMacro(<< "No input!");
    return;
  }

  this->GetInputAlgorithm()->Update();
  vtkIdType numPts = input->GetNumberOfPoints();
  if (numPts == 0)
  {
    vtkDebugMacro(<< "No points!");
    return;
  }

  if (this->LookupTable == nullptr)
  {
    this->CreateDefaultLookupTable();
  }

  vtkOpenGLRenderWindow* renWin = static_cast<vtkOpenGLRenderWindow*>(viewport->GetVTKWindow());
  vtkOpenGLState* ostate = renWin->GetState();

  this->ResourceCallback->RegisterGraphicsResources(renWin);

  vtkRenderer* ren = vtkRenderer::SafeDownCast(viewport);
  vtkHardwareSelector* selector = ren->GetSelector();
  if (selector)
  {
    selector->BeginRenderProp();
  }

  int picking = (selector ? 1 : 0);
  if (picking != this->LastPickState)
  {
    this->LastPickState = picking;
    this->PickStateChanged.Modified();
  }

  // Assume we want to do Zbuffering for now.
  // we may turn this off later
  ostate->vtkglDepthMask(GL_TRUE);

  // Update the VBO if needed.
  if (this->VBOUpdateTime < this->GetMTime() || this->VBOUpdateTime < actor->GetMTime() ||
    this->VBOUpdateTime < input->GetMTime() ||
    (this->TransformCoordinate &&
      (this->VBOUpdateTime < viewport->GetMTime() ||
        this->VBOUpdateTime < viewport->GetVTKWindow()->GetMTime())))
  {
    this->UpdateVBO(actor, viewport);
    this->VBOUpdateTime.Modified();