Method ExecuteFaceQuads

Filters/Geometry/vtkDataSetSurfaceFilter.cxx:830–954

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void vtkDataSetSurfaceFilter::ExecuteFaceQuads(vtkDataSet* input, vtkPolyData* output, int maxFlag,
  vtkIdType* ext, int aAxis, int bAxis, int cAxis, vtkIdType* wholeExt, bool checkVisibility)
{
  vtkPoints* outPts;
  vtkCellArray* outPolys;
  vtkPointData *inPD, *outPD;
  vtkCellData *inCD, *outCD;
  vtkIdType pInc[3];
  vtkIdType qInc[3];
  vtkIdType cOutInc;
  double pt[3];
  vtkIdType inStartPtId;
  vtkIdType inStartCellId;
  vtkIdType outStartPtId;
  vtkIdType outPtId;
  vtkIdType inId, outId;
  vtkIdType ib, ic;
  int aA2, bA2, cA2;

  outPts = output->GetPoints();
  outPD = output->GetPointData();
  inPD = input->GetPointData();
  outCD = output->GetCellData();
  inCD = input->GetCellData();

  pInc[0] = 1;
  pInc[1] = (ext[1] - ext[0] + 1);
  pInc[2] = (ext[3] - ext[2] + 1) * pInc[1];
  // quad increments (cell increments, but cInc could be confused with c axis).
  qInc[0] = 1;
  qInc[1] = ext[1] - ext[0];
  // The conditions are for when we have one or more degenerate axes (2d or 1d cells).
  if (qInc[1] == 0)
  {
    qInc[1] = 1;
  }
  qInc[2] = (ext[3] - ext[2]) * qInc[1];
  if (qInc[2] == 0)
  {
    qInc[2] = qInc[1];
  }

  // Temporary variables to avoid many multiplications.
  aA2 = aAxis * 2;
  bA2 = bAxis * 2;
  cA2 = cAxis * 2;

  // We might as well put the test for this face here.
  if (ext[bA2] == ext[bA2 + 1] || ext[cA2] == ext[cA2 + 1])
  {
    return;
  }
  if (maxFlag)
  {
    if (ext[aA2 + 1] < wholeExt[aA2 + 1])
    {
      return;
    }