Method IntersectWithLine

Filters/General/vtkOBBTree.cxx:676–901

------------------------------------------------------------------------------ Take the passed line segment and intersect it with the OBB cells. This method assumes that the data set is a vtkPolyData that describes a closed surface, and the intersection points that are returned in 'points' alternate between entrance points and exit points. The return value of the function is 0 if no intersection w

// 1 if point 'p1' lies inside the polydata surface, or -1 if point 'p1'
// lies outside the polydata surface.
int vtkOBBTree::IntersectWithLine(
  const double p1[3], const double p2[3], vtkPoints* points, vtkIdList* cellIds)
{
  if (this->DataSet == nullptr)
  {
    if (points)
    {
      points->SetNumberOfPoints(0);
    }
    if (cellIds)
    {
      cellIds->SetNumberOfIds(0);
    }
    return 0;
  }
  if (!this->DataSet->IsA("vtkPolyData"))
  {
    vtkErrorMacro("IntersectWithLine: this method requires a vtkPolyData");
    return 0;
  }

  int rval = 0; // return value for function
  vtkIdList* cells;

  // temporary list used to sort intersections
  int listSize = 0;
  int listMaxSize = 10;
  double* distanceList = new double[listMaxSize];
  vtkIdType* cellList = new vtkIdType[listMaxSize];
  char* senseList = new char[listMaxSize];

  double point[3];
  double distance = 0;
  int sense = 0;
  vtkIdType cellId;

  // compute line vector from p1 to p2
  double v12[3];
  v12[0] = p2[0] - p1[0];
  v12[1] = p2[1] - p1[1];
  v12[2] = p2[2] - p1[2];

  vtkOBBNode** OBBstack = new vtkOBBNode*[this->GetLevel() + 1];
  OBBstack[0] = this->Tree;

  // depth counter for stack
  int depth = 1;
  while (depth > 0)
  { // simulate recursion without the overhead or limitations
    vtkOBBNode* node = OBBstack[--depth];

    // check for intersection with node
    if (this->LineIntersectsNode(node, p1, p2))
    {
      if (node->Kids == nullptr)
      { // then this is a leaf node...get Cells
        cells = node->Cells;
        vtkIdType numCells = cells->GetNumberOfIds();