From: erg <devnull@localhost>
Date: Fri, 28 Jan 2011 21:24:44 +0000 (+0000)
Subject: Allow twopi to note vertex picked as root if not specified
X-Git-Tag: LAST_LIBGRAPH~32^2~1082
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=10eb4da7dd932c000d51731e748b2c0fec7a303b;p=graphviz

Allow twopi to note vertex picked as root if not specified
---

diff --git a/lib/twopigen/circle.c b/lib/twopigen/circle.c
index 67714177d..7dcdc52b3 100644
--- a/lib/twopigen/circle.c
+++ b/lib/twopigen/circle.c
@@ -339,7 +339,7 @@ static void dumpGraph(Agraph_t * g)
  *  Also, if center != 0, we are guaranteed that center is
  *  in the graph.
  */
-void circleLayout(Agraph_t * sg, Agnode_t * center)
+Agnode_t* circleLayout(Agraph_t * sg, Agnode_t * center)
 {
     int maxNStepsToCenter;
 
@@ -347,7 +347,7 @@ void circleLayout(Agraph_t * sg, Agnode_t * center)
 	Agnode_t *n = agfstnode(sg);
 	ND_pos(n)[0] = 0;
 	ND_pos(n)[1] = 0;
-	return;
+	return center;
     }
 
     initLayout(sg);
@@ -367,4 +367,5 @@ void circleLayout(Agraph_t * sg, Agnode_t * center)
 
     setAbsolutePos(sg, maxNStepsToCenter);
     /* dumpGraph (sg); */
+    return center;
 }
diff --git a/lib/twopigen/circle.h b/lib/twopigen/circle.h
index c54ebb6ad..822f5015f 100644
--- a/lib/twopigen/circle.h
+++ b/lib/twopigen/circle.h
@@ -39,7 +39,7 @@ extern "C" {
 #define SPAN(n) (RDATA(n)->span)
 #define THETA(n) (RDATA(n)->theta)
 
-    extern void circleLayout(Agraph_t * sg, Agnode_t * center);
+    extern Agnode_t* circleLayout(Agraph_t * sg, Agnode_t * center);
     extern void twopi_layout(Agraph_t * g);
     extern void twopi_cleanup(Agraph_t * g);
     extern void twopi_init_graph(graph_t * g);
diff --git a/lib/twopigen/twopiinit.c b/lib/twopigen/twopiinit.c
index 0d3d5e9b0..b0ee53b7a 100644
--- a/lib/twopigen/twopiinit.c
+++ b/lib/twopigen/twopiinit.c
@@ -65,14 +65,21 @@ void twopi_layout(Agraph_t * g)
 {
     Agnode_t *ctr = 0;
     char *s;
+    int setRoot = 0;
 
     twopi_init_graph(g);
     s = agget(g, "root");
-    if (s && (*s != '\0')) {
-	ctr = agfindnode(g, s);
-	if (!ctr) {
-	    agerr(AGWARN, "specified root node \"%s\" was not found.", s);
-	    agerr(AGPREV, "Using default calculation for root node\n");
+    if ((s = agget(g, "root"))) {
+	if (*s) {
+	    ctr = agfindnode(g, s);
+	    if (!ctr) {
+		agerr(AGWARN, "specified root node \"%s\" was not found.", s);
+		agerr(AGPREV, "Using default calculation for root node\n");
+		setRoot = 1;
+	    }
+	}
+	else {
+	    setRoot = 1;
 	}
     }
     if (agnnodes(g)) {
@@ -84,7 +91,9 @@ void twopi_layout(Agraph_t * g)
 
 	ccs = ccomps(g, &ncc, 0);
 	if (ncc == 1) {
-	    circleLayout(g, ctr);
+	    c = circleLayout(g, ctr);
+	    if (setRoot && !ctr)
+		ctr = c;
 	    free(ND_alg(agfstnode(g)));
 	    adjustNodes(g);
 	    spline_edges(g);
@@ -100,7 +109,9 @@ void twopi_layout(Agraph_t * g)
 		else
 		    c = 0;
 		nodeInduce(sg);
-		circleLayout(sg, c);
+		c = circleLayout(sg, c);
+	        if (setRoot && !ctr)
+		    ctr = c;
 		adjustNodes(sg);
 		setEdgeType (sg, ET_LINE);
 		spline_edges(sg);
@@ -113,6 +124,8 @@ void twopi_layout(Agraph_t * g)
 	}
 	free(ccs);
     }
+    if (setRoot)
+	agset (g, "root", agnameof (ctr)); 
     dotneato_postprocess(g);
 
 }