Method ContiguousEdges

Filters/General/vtkCellValidator.cxx:271–306

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//------------------------------------------------------------------------------
bool vtkCellValidator::ContiguousEdges(vtkCell* twoDimensionalCell, double tolerance)
{
  // Ensures that a two-dimensional cell's edges are contiguous.
  //
  // NB: we cannot simply test the values of point ids, since cells have the
  //     tricky habit of generating their edge cells on the fly and cell Ids are
  //     only congruent w.r.t. a single point array. To be thorough, we need to
  //     compare point values.

  assert(twoDimensionalCell->GetCellDimension() == 2);

  double points[4][3];
  double *p[2] = { points[0], points[1] }, *x[2] = { points[2], points[3] }, u, v;
  vtkCell* edge = twoDimensionalCell->GetEdge(0);
  vtkIdType nEdges = twoDimensionalCell->GetNumberOfEdges();
  // Need to use local indices, not global
  edge->GetPoints()->GetPoint(0, p[0]);
  edge->GetPoints()->GetPoint(1, p[1]);
  for (vtkIdType i = 0; i < nEdges; i++)
  {
    edge = twoDimensionalCell->GetEdge((i + 1) % nEdges);
    // Need to use local indices, not global
    edge->GetPoints()->GetPoint(0, x[0]);
    edge->GetPoints()->GetPoint(1, x[1]);

    vtkLine::Intersection(p[0], p[1], x[0], x[1], u, v, vtkMath::Inf());
    if ((std::abs(u) > tolerance && std::abs(1. - u) > tolerance) ||
      (std::abs(v) > tolerance && std::abs(1. - v) > tolerance))
    {
      return false;
    }
    p[0] = x[0];
    p[1] = x[1];
  }
  return true;
}

//------------------------------------------------------------------------------
namespace