Prout 4 Diop

int IsoSurfacer::ComputeSimpleIntersection(vtkCell *tet) {
    vtkCell *edge;
    double *p = new double[3];
    vtkIdType *ids = new vtkIdType[6],
              *edges = new vtkIdType[8];
    int idn = 0;
    for (unsigned i=0; i<6; i++) {
        edge = tet->GetEdge(i);
        if (!IsCellOnLevelSet(edge)) continue;
        edges[2*idn]   = edge->GetPointId(0);
        edges[2*idn+1] = edge->GetPointId(1);
        ComputeEdgeIntersection(edge->GetPointId(0),
                                edge->GetPointId(1), p);
        ids[idn] = Output->GetPoints()->InsertNextPoint(p);
        idn++;
        if (idn==4) {
            ReOrderTetEdges(edges, ids);
            break;
        }
    }
    Output->InsertNextCell(VTK_POLYGON, idn, ids);
    delete[] ids;
    delete[] edges;
    delete[] p;
    return 0;
}

int IsoSurfacer::ReOrderTetEdges(
        vtkIdType *edges, vtkIdType *ids) const {
    int i;
    vtkIdType buf1, buf2, buf3;
    if (edges[2] != edges[0]
     && edges[2] != edges[1]
     && edges[3] != edges[0]
     && edges[3] != edges[1]) {
        buf1 = edges[2];
        buf2 = edges[3];
        buf3 = ids[1];
        edges[2] = edges[4];
        edges[3] = edges[5];
        ids[1] = ids[2];
        edges[4] = buf1;
        edges[5] = buf2;
        ids[2] = buf3;
        return 0;
    }
    if (edges[4] != edges[2]
     && edges[4] != edges[3]
     && edges[5] != edges[2]
     && edges[5] != edges[3]) {
        buf1 = edges[4];
        buf2 = edges[5];
        buf3 = ids[2];
        edges[4] = edges[6];
        edges[5] = edges[7];
        ids[2] = ids[3];
        edges[6] = buf1;
        edges[7] = buf2;
        ids[3] = buf3;
    }
    return 0;
}