Method CellGrid

Filters/General/vtkBoxClipDataSet.cxx:986–1534

------------------------------------------------------------------------------ Tetra Grid : Subdivide cells in consistent tetrahedra. For each cell, search the smallest global index. Case Tetrahedron(10): Just insert this cell in the newCellArray Case Voxel(11) or Hexahedron(12): - for each face: looking for the diagonal edge with the smallest index - 2 possibilities: subdivide a cell in 5 or 6

//
//------------------------------------------------------------------------------
void vtkBoxClipDataSet::CellGrid(
  vtkIdType typeobj, vtkIdType npts, const vtkIdType* cellIds, vtkCellArray* newCellArray)
{
  vtkIdType tab[4];
  vtkIdType tabp[5];
  vtkIdType ptstriangle = 3;
  vtkIdType ptstetra = 4;
  vtkIdType xmin;
  vtkIdType idt;
  int i, j;
  unsigned int id = 0;
  unsigned int idpy = 0;

  unsigned int Edg_f[6][2]; // edge selected of each face
  unsigned int idv[4];

  unsigned int idopos;
  unsigned int numbertetra;

  constexpr vtkIdType triPassThrough[3] = { 0, 1, 2 };
  vtkIdType tri[3];
  vtkIdType line[2];

  switch (typeobj)
  {
    case VTK_VERTEX:
    case VTK_POLY_VERTEX:
      for (idt = 0; idt < npts; idt++)
      {
        newCellArray->InsertNextCell(1, &idt);
      }
      break;

    case VTK_LINE:
    case VTK_POLY_LINE:
      for (idt = 0; idt < npts - 1; idt++)
      {
        line[0] = idt;
        line[1] = idt + 1;
        newCellArray->InsertNextCell(2, line);
      }
      break;

    case VTK_TRIANGLE: // 5
    case VTK_QUADRATIC_TRIANGLE:
    case VTK_BIQUADRATIC_TRIANGLE:
      newCellArray->InsertNextCell(ptstriangle, triPassThrough);
      break;

    case VTK_TRIANGLE_STRIP: // 6
      for (idt = 0; idt < npts - 2; idt++)
      {
        if (idt % 2 == 0)
        {
          tri[0] = idt;
          tri[1] = idt + 1;
          tri[2] = idt + 2;
        }