Method BuildLeader

Rendering/Annotation/vtkLeaderActor2D.cxx:112–393

------------------------------------------------------------------------------

//------------------------------------------------------------------------------
void vtkLeaderActor2D::BuildLeader(vtkViewport* viewport)
{
  // Check to see whether we need to rebuild-----------------------------
  int positionsHaveChanged = 0;
  if (viewport->GetMTime() > this->BuildTime ||
    (viewport->GetVTKWindow() && viewport->GetVTKWindow()->GetMTime() > this->BuildTime))
  {
    int* lastPosition = this->PositionCoordinate->GetComputedViewportValue(viewport);
    int* lastPosition2 = this->Position2Coordinate->GetComputedViewportValue(viewport);
    if (lastPosition[0] != this->LastPosition[0] || lastPosition[1] != this->LastPosition[1] ||
      lastPosition2[0] != this->LastPosition2[0] || lastPosition2[1] != this->LastPosition2[1])
    {
      positionsHaveChanged = 1;
    }
  }

  const int* size = viewport->GetSize();
  int viewportSizeHasChanged = 0;
  // See whether fonts have to be rebuilt (font size depends on viewport size)
  if (this->LastSize[0] != size[0] || this->LastSize[1] != size[1])
  {
    viewportSizeHasChanged = 1;
    this->LastSize[0] = size[0];
    this->LastSize[1] = size[1];
  }

  if (!positionsHaveChanged && !viewportSizeHasChanged && this->GetMTime() < this->BuildTime &&
    this->LabelTextProperty->GetMTime() < this->BuildTime)
  {
    return;
  }

  // Okay, we have some work to do. We build the leader in three parts:
  // 1) the line connecting the two points, 2) the text label, and 3) the
  // arrow head(s) if any.
  vtkDebugMacro(<< "Rebuilding leader"); //---------------------------------

  // Initialize the data
  this->LeaderPoints->Initialize();
  this->LeaderLines->Initialize();
  this->LeaderArrows->Initialize();
  this->LeaderActor->SetProperty(this->GetProperty());
  this->LabelMapper->SetTextProperty(this->LabelTextProperty);

  // The easiest part is determining the two end points of the line.
  double p1[3], p2[3], ray[3];
  int* x = this->PositionCoordinate->GetComputedViewportValue(viewport);
  p1[0] = static_cast<double>(x[0]);
  p1[1] = static_cast<double>(x[1]);
  p1[2] = 0.0;
  this->LastPosition[0] = x[0];
  this->LastPosition[1] = x[1];

  x = this->Position2Coordinate->GetComputedViewportValue(viewport);
  p2[0] = static_cast<double>(x[0]);
  p2[1] = static_cast<double>(x[1]);
  p2[2] = 0.0;
  this->LastPosition2[0] = x[0];