Method LassoSelect

Views/Infovis/vtkParallelCoordinatesRepresentation.cxx:1393–1436

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//------------------------------------------------------------------------------
void vtkParallelCoordinatesRepresentation::LassoSelect(
  int brushClass, int brushOperator, vtkPoints* brushPoints)
{
  if (brushPoints->GetNumberOfPoints() < 2)
    return;

  int position = -1, prevPosition = -1;

  vtkSmartPointer<vtkBivariateLinearTableThreshold> threshold =
    nullptr; // vtkSmartPointer<vtkBivariateLinearTableThreshold>::New();
  vtkSmartPointer<vtkIdTypeArray> allIds = vtkSmartPointer<vtkIdTypeArray>::New();

  // for every point in the brush, compute a line in XY space.  A point in XY space satisfies
  // the threshold if it is contained WITHIN all such lines.
  vtkSmartPointer<vtkPoints> posPoints = vtkSmartPointer<vtkPoints>::New();
  for (int i = 0; i < brushPoints->GetNumberOfPoints() - 1; i++)
  {
    double* p = brushPoints->GetPoint(i);
    position = this->ComputePointPosition(p);

    // if we have a valid position
    if (position >= 0 && position < this->NumberOfAxes)
    {
      // position has changed, that means we need to create a new threshold object.
      if (prevPosition != position && i > 0)
      {
        this->LassoSelectInternal(posPoints, allIds);
        posPoints->Initialize();
      }

      posPoints->InsertNextPoint(p);
    }
    prevPosition = position;
  }

  if (posPoints->GetNumberOfPoints() > 0)
  {
    this->LassoSelectInternal(posPoints, allIds);
  }

  this->FunctionTextMapper->SetInput("No function selected.");
  this->FunctionTextActor->VisibilityOff();
  this->SelectRows(brushClass, brushOperator, allIds);
}

//------------------------------------------------------------------------------
void vtkParallelCoordinatesRepresentation::LassoSelectInternal(