From e74f3329579fac8062618aceb4f57e1ab5663a22 Mon Sep 17 00:00:00 2001
From: "Emden R. Gansner" <erg@alum.mit.edu>
Date: Tue, 28 Jan 2014 14:28:06 -0500
Subject: [PATCH] Provide two entry points for "straight" line generation since
 dot works on different assumptions than other routing

---
 lib/common/render.h   |  1 +
 lib/common/routespl.c | 38 ++++++++++++++++++++++++++++++++++----
 2 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/lib/common/render.h b/lib/common/render.h
index a468856c5..9515ded74 100644
--- a/lib/common/render.h
+++ b/lib/common/render.h
@@ -87,6 +87,7 @@ extern "C" {
 			    boolean left_inside);
     extern shape_desc *bind_shape(char *name, node_t *);
     extern void makeStraightEdge(graph_t * g, edge_t * e, int edgetype, splineInfo * info);
+    extern void makeStraightEdges(graph_t* g, edge_t** edges, int e_cnt, int et, splineInfo* sinfo);
     extern void clip_and_install(edge_t * fe, node_t * hn,
 	pointf * ps, int pn, splineInfo * info);
     extern char* charsetToStr (int c);
diff --git a/lib/common/routespl.c b/lib/common/routespl.c
index 7e66c4381..a84eefa98 100644
--- a/lib/common/routespl.c
+++ b/lib/common/routespl.c
@@ -930,22 +930,52 @@ static void bend(pointf spl[4], pointf centroid)
  *
  * FIX: handle ports on boundary?
  */
+#define MAX_EDGE 20
 void 
 makeStraightEdge(graph_t * g, edge_t * e, int et, splineInfo* sinfo)
+{
+    edge_t *e0;
+    edge_t** edges;
+    edge_t* elist[MAX_EDGE];
+    int i, e_cnt;
+
+    e_cnt = 0;
+    e0 = e;
+    while ((e0 = ED_to_virt(e0))) e_cnt++;
+
+    if (e_cnt <= MAX_EDGE)
+	edges = elist;
+    else
+	edges = N_NEW(e_cnt,edge_t*);
+    e0 = e;
+    for (i = 0; i < e_cnt; i++) {
+	edges[i] = e0;
+	e0 = ED_to_virt(e0);
+    }
+    makeStraightEdges (g, edges, e_cnt, et, sinfo);
+    if (e_cnt > MAX_EDGE) free (edges);
+
+}
+
+void 
+makeStraightEdges(graph_t * g, edge_t** edges, int e_cnt, int et, splineInfo* sinfo)
 {
     pointf dumb[4];
-    node_t *n = agtail(e);
-    node_t *head = aghead(e);
-    int e_cnt = ED_count(e);
+    node_t *n;
+    node_t *head;
     int curved = (et == ET_CURVED);
     pointf perp;
     pointf del;
     edge_t *e0;
+    edge_t *e;
     int i, j, xstep, dx;
     double l_perp;
     pointf dumber[4];
     pointf p, q;
 
+    e = edges[0];
+    n = agtail(e);
+    head = aghead(e);
     p = dumb[1] = dumb[0] = add_pointf(ND_coord(n), ED_tail_port(e).p);
     q = dumb[2] = dumb[3] = add_pointf(ND_coord(head), ED_head_port(e).p);
     if ((e_cnt == 1) || Concentrate) {
@@ -978,6 +1008,7 @@ makeStraightEdge(graph_t * g, edge_t * e, int et, splineInfo* sinfo)
     }
 
     for (i = 0; i < e_cnt; i++) {
+	e0 = edges[i];
 	if (aghead(e0) == head) {
 	    p = dumb[0];
 	    q = dumb[3];
@@ -1007,7 +1038,6 @@ makeStraightEdge(graph_t * g, edge_t * e, int et, splineInfo* sinfo)
 	    clip_and_install(e0, aghead(e0), dumber, 4, sinfo);
 
 	addEdgeLabels(g, e0, p, q);
-	e0 = ED_to_virt(e0);
 	dumb[1].x += del.x;
 	dumb[1].y += del.y;
 	dumb[2].x += del.x;
-- 
2.40.0