663   vtkHyperPoint *sPrev, *sPtr;  in BuildTube()  local
720     sPrev = this->Streamers[ptId].GetHyperPoint(0);  in BuildTube()
724     i = (sPrev->W[ix] > sPrev->W[iy] ? ix : iy);  in BuildTube()
725     if ( sPrev->W[i] == 0.0 )  in BuildTube()
731       sFactor = this->Radius / sPrev->W[i];  in BuildTube()
739     dOffset = sPrev->D;  in BuildTube()
742     i++, sPrev=sPtr, sPtr=this->Streamers[ptId].GetHyperPoint(i) )  in BuildTube()
747       while ( dOffset >= sPrev->D && dOffset < sPtr->D )  in BuildTube()
749         r = (dOffset - sPrev->D) / (sPtr->D - sPrev->D);  in BuildTube()
753           x[j] = sPrev->X[j] + r * (sPtr->X[j] - sPrev->X[j]);  in BuildTube()
754           v[j] = sPrev->V[j][iv] + r * (sPtr->V[j][iv] - sPrev->V[j][iv]);  in BuildTube()
755           r1[j] = sPrev->V[j][ix] + r * (sPtr->V[j][ix] - sPrev->V[j][ix]);  in BuildTube()
756           r2[j] = sPrev->V[j][iy] + r * (sPtr->V[j][iy] - sPrev->V[j][iy]);  in BuildTube()
757           w[j] = sPrev->W[j] + r * (sPtr->W[j] - sPrev->W[j]);  in BuildTube()
777           s = sPrev->S + r * (sPtr->S - sPrev->S);  in BuildTube()