142     , fFirstEdgeBelow(nullptr), fLastEdgeBelow(nullptr)  in Vertex()
153     Edge*   fFirstEdgeBelow;  // Linked list of edges below this vertex.  member
735     for (next = v->fFirstEdgeBelow; next; next = next->fNextEdgeBelow) {  in insert_edge_below()
742         edge, prev, next, &v->fFirstEdgeBelow, &v->fLastEdgeBelow);  in insert_edge_below()
756         edge, &edge->fTop->fFirstEdgeBelow, &edge->fTop->fLastEdgeBelow);  in remove_edge_below()
911     for (Edge* edge = src->fFirstEdgeBelow; edge;) {  in merge_vertices()
1125         if (!v->fFirstEdgeAbove && !v->fFirstEdgeBelow) {  in simplify()
1137             if (v->fFirstEdgeBelow) {  in simplify()
1138 …              for (Edge* edge = v->fFirstEdgeBelow; edge != nullptr; edge = edge->fNextEdgeBelow) {  in simplify()
1163         for (Edge* e = v->fFirstEdgeBelow; e; e = e->fNextEdgeBelow) {  in simplify()
1178         if (!v->fFirstEdgeAbove && !v->fFirstEdgeBelow) {  in tessellate()
1203         for (Edge* e = v->fFirstEdgeBelow; e; e = e->fNextEdgeBelow) {  in tessellate()
1228             if (!v->fFirstEdgeBelow) {  in tessellate()
1236         if (v->fFirstEdgeBelow) {  in tessellate()
1262             Edge* leftEdge = v->fFirstEdgeBelow;  in tessellate()