218     VertexType classify(Vertex **e0, Vertex **e1);
455 Vertex::VertexType Vertex::classify(Vertex **e0, Vertex **e1) {  in classify()  argument
469             *e0 = prev();  in classify()
475                 *e0 = this;  in classify()
478                 *e0 = prev();  in classify()
485                 *e0 = this;     // flat to the left  in classify()
489                 *e0 = prev();   // concave to the left  in classify()
497             *e0 = this;  in classify()
503                 *e0 = prev();  in classify()
506                 *e0 = this;  in classify()
513                 *e0 = this;     // flat to the left  in classify()
517                 *e0 = prev();   // convex to the left - try monotone first  in classify()
526                 *e0 = prev();   // flat to the left  in classify()
530                 *e0 = this;     // concave on the left - defer  in classify()
537                 *e0 = prev();   // flat to the left  in classify()
541                 *e0 = this;     // convex to the left - try monotone first  in classify()
549                 *e0 = prev();   // flat to the left  in classify()
553                 *e0 = this;     // flat to the left  in classify()
583         Vertex *e0, *e1;  in PrintVertices()  local
584         Vertex::VertexType type = vt[i].classify(&e0, &e1);  in PrintVertices()
589                     GetVertexTypeString(type), e0 - vt, e1 - vt);  in PrintVertices()
608         Vertex *e0, *e1;  in PrintVertexPtrs()  local
610         Vertex::VertexType type = vt->classify(&e0, &e1);  in PrintVertexPtrs()
615                     GetVertexTypeString(type), e0 - vtBase, e1 - vtBase);  in PrintVertexPtrs()
711         Vertex *e0, *e1;  in ConvertPointsToVertices()  local
713         switch (vt->classify(&e0, &e1)) {  in ConvertPointsToVertices()
716                 DebugPrintf("MONOTONE %d %d\n", e0 - vta, e1 - vta);  in ConvertPointsToVertices()
718                 t = incompleteTrapezoids.getTrapezoidWithEdge(e0);  in ConvertPointsToVertices()
727                 if (e0 == t->left())  // Replace the left edge.  in ConvertPointsToVertices()
736                 DebugPrintf("CONVEX %d %d\n", e0 - vta, e1 - vta);  in ConvertPointsToVertices()
744                     incompleteTrapezoids.insertNewTrapezoid(vt, t->left(), e0);  in ConvertPointsToVertices()
748                     incompleteTrapezoids.insertNewTrapezoid(vt, e0, e1);  in ConvertPointsToVertices()
753                 DebugPrintf("CONCAVE %d %d\n", e0 - vta, e1 - vta);  in ConvertPointsToVertices()
755                 t = incompleteTrapezoids.getTrapezoidWithEdge(e0);  in ConvertPointsToVertices()
762                 if (e0 == t->left() && e1 == t->right()) {  in ConvertPointsToVertices()