Method FindCloseNBoundedPoints

Common/DataModel/vtkStaticPointLocator2D.cxx:1208–1321

//------------------------------------------------------------------------------
template <typename TIds>
double BucketList2D<TIds>::FindCloseNBoundedPoints(int N, const double x[3], vtkIdList* result)
{
  int i, j;
  double dist2;
  double pt[3];
  int level;
  vtkIdType ptId, cno, numIds;
  int ij[2], *nei;
  NeighborBuckets2D buckets;
  const vtkLocatorTuple<TIds>* ids;

  //  Find the bucket the point is in.
  this->GetBucketIndices(x, ij);

  // Gather points keeping track of maximum radius
  level = 0;
  double maxDist2 = 0.0;
  vtkDist2TupleType sortedPts;
  sortedPts.reserve(128);

  // Start in the current bucket and expand out to grab first N points. Keep
  // track of maximum distance.
  this->GetBucketNeighbors(&buckets, ij, this->Divisions, level);
  while (buckets.GetNumberOfNeighbors() > 0)
  {
    // For all buckets in this level
    for (i = 0; i < buckets.GetNumberOfNeighbors(); i++)
    {
      nei = buckets.GetPoint(i);
      cno = nei[0] + nei[1] * this->xD;
      if ((numIds = this->GetNumberOfIds(cno)) > 0)
      {
        ids = this->GetIds(cno);
        for (j = 0; j < numIds; j++)
        {
          ptId = ids[j].PtId;
          this->DataSet->GetPoint(ptId, pt);
          dist2 = Distance2BetweenPoints2D(x, pt);
          // accumulate first N points
          if (static_cast<int>(sortedPts.size()) < N)
          {
            maxDist2 = (dist2 > maxDist2 ? dist2 : maxDist2);
            sortedPts.emplace_back(ptId, dist2);
          }
          else if (dist2 <= maxDist2)
          {
            sortedPts.emplace_back(ptId, dist2);
          }
        }
      } // if points in bucket
    }   // for buckets in this level
    level++;
    // As soon as N points in this level found, jump out.
    if (static_cast<int>(sortedPts.size()) >= N)
    {
      goto FOUND_N;
    }
    this->GetBucketNeighbors(&buckets, ij, this->Divisions, level);