Method GetNextCell

Common/ExecutionModel/vtkSimpleScalarTree.cxx:305–343

------------------------------------------------------------------------------ Return the next cell that may contain scalar value specified to initialize traversal. The value nullptr is returned if the list is exhausted. Make sure that InitTraversal() has been invoked first or you'll get erratic behavior.

// exhausted. Make sure that InitTraversal() has been invoked first or
// you'll get erratic behavior.
vtkCell* vtkSimpleScalarTree::GetNextCell(
  vtkIdType& cellId, vtkIdList*& cellPts, vtkDataArray* cellScalars)
{
  double s, min = VTK_DOUBLE_MAX, max = (-VTK_DOUBLE_MAX);
  vtkIdType i, numScalars;
  vtkCell* cell;
  vtkIdType numCells = this->NumCells;

  while (this->TreeIndex < this->TreeSize)
  {
    for (; this->ChildNumber < this->BranchingFactor && this->CellId < numCells;
         this->ChildNumber++, this->CellId++)
    {
      cell = this->DataSet->GetCell(this->CellId);
      cellPts = cell->GetPointIds();
      numScalars = cellPts->GetNumberOfIds();
      cellScalars->SetNumberOfTuples(numScalars);
      this->Scalars->GetTuples(cellPts, cellScalars);
      for (i = 0; i < numScalars; i++)
      {
        s = cellScalars->GetTuple1(i);
        min = std::min(s, min);
        max = std::max(s, max);
      }
      if (this->ScalarValue >= min && this->ScalarValue <= max)
      {
        cellId = this->CellId;
        this->ChildNumber++; // prepare for next time
        this->CellId++;
        return cell;
      }
    } // for each cell in this leaf

    // If here, must have not found anything in this leaf
    this->FindNextLeaf(this->TreeIndex, this->Level);
  } // while not all leafs visited

  return nullptr;
}

//------------------------------------------------------------------------------
// Return the number of cell batches.