Method GetNextVisibleQuadFromHash

Filters/Geometry/vtkDataSetSurfaceFilter.cxx:2684–2714

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//------------------------------------------------------------------------------
vtkFastGeomQuad* vtkDataSetSurfaceFilter::GetNextVisibleQuadFromHash()
{
  vtkFastGeomQuad* quad;

  quad = this->QuadHashTraversal;

  // Move till traversal until we have a quad to return.
  // Note: the current traversal has not been returned yet.
  while (quad == nullptr || quad->SourceId == -1)
  {
    if (quad)
    { // The quad must be hidden.  Move to the next.
      quad = quad->Next;
    }
    else
    { // must be the end of the linked list.  Move to the next bin.
      this->QuadHashTraversalIndex += 1;
      if (this->QuadHashTraversalIndex >= this->QuadHashLength)
      { // There are no more bins.
        this->QuadHashTraversal = nullptr;
        return nullptr;
      }
      quad = this->QuadHash[this->QuadHashTraversalIndex];
    }
  }

  // Now we have a quad to return.  Set the traversal to the next entry.
  this->QuadHashTraversal = quad->Next;

  return quad;
}

//------------------------------------------------------------------------------
vtkIdType vtkDataSetSurfaceFilter::GetOutputPointId(