Function cvNextGraphItem

deps/opencv/modules/core/src/datastructs.cpp:3089–3240

CV_IMPL int
cvNextGraphItem( CvGraphScanner* scanner )
{
    int code = -1;
    CvGraphVtx* vtx;
    CvGraphVtx* dst;
    CvGraphEdge* edge;
    CvGraphItem item;

    if( !scanner || !(scanner->stack))
        CV_Error( CV_StsNullPtr, "Null graph scanner" );

    dst = scanner->dst;
    vtx = scanner->vtx;
    edge = scanner->edge;

    for(;;)
    {
        for(;;)
        {
            if( dst && !CV_IS_GRAPH_VERTEX_VISITED(dst) )
            {
                scanner->vtx = vtx = dst;
                edge = vtx->first;
                dst->flags |= CV_GRAPH_ITEM_VISITED_FLAG;

                if((scanner->mask & CV_GRAPH_VERTEX))
                {
                    scanner->vtx = vtx;
                    scanner->edge = vtx->first;
                    scanner->dst = 0;
                    code = CV_GRAPH_VERTEX;
                    return code;
                }
            }

            while( edge )
            {
                dst = edge->vtx[vtx == edge->vtx[0]];

                if( !CV_IS_GRAPH_EDGE_VISITED(edge) )
                {
                    // Check that the edge is outgoing:
                    if( !CV_IS_GRAPH_ORIENTED( scanner->graph ) || dst != edge->vtx[0] )
                    {
                        edge->flags |= CV_GRAPH_ITEM_VISITED_FLAG;

                        if( !CV_IS_GRAPH_VERTEX_VISITED(dst) )
                        {
                            item.vtx = vtx;
                            item.edge = edge;

                            vtx->flags |= CV_GRAPH_SEARCH_TREE_NODE_FLAG;

                            cvSeqPush( scanner->stack, &item );

                            if( scanner->mask & CV_GRAPH_TREE_EDGE )
                            {