From: erg <devnull@localhost>
Date: Fri, 2 Jul 2010 15:00:49 +0000 (+0000)
Subject: Move makePortLabels() and addEdgeLabels() from neatogen to common
X-Git-Tag: LAST_LIBGRAPH~32^2~1289
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=8785a9ea2dd12233c15852abc3afbb1eb1558603;p=graphviz

Move makePortLabels() and addEdgeLabels() from neatogen to common
---

diff --git a/lib/common/render.h b/lib/common/render.h
index fdfefcbbc..34089c755 100644
--- a/lib/common/render.h
+++ b/lib/common/render.h
@@ -135,6 +135,8 @@ extern "C" {
     extern char **parse_style(char *s);
     extern void place_graph_label(Agraph_t *);
     extern void place_portlabel(edge_t * e, boolean head_p);
+    extern void makePortLabels(edge_t * e);
+    extern void addEdgeLabels(graph_t* g, edge_t * e, pointf rp, pointf rq);
     extern void pop_obj_state(GVJ_t *job);
     extern obj_state_t* push_obj_state(GVJ_t *job);
     extern int rank(graph_t * g, int balance, int maxiter);
diff --git a/lib/common/splines.c b/lib/common/splines.c
index df848b25e..b05fc53ab 100644
--- a/lib/common/splines.c
+++ b/lib/common/splines.c
@@ -1114,6 +1114,159 @@ makeSelfEdge(path * P, edge_t * edges[], int ind, int cnt, double sizex,
     else assert(0);
 }
 
+/* makePortLabels:
+ * Add head and tail labels if necessary and update bounding box.
+ */
+void makePortLabels(edge_t * e)
+{
+    if (ED_head_label(e) && !ED_head_label(e)->set) {
+	place_portlabel(e, TRUE);
+	updateBB(agraphof(agtail(e)), ED_head_label(e));
+    }
+    if (ED_tail_label(e) && !ED_tail_label(e)->set) {
+	place_portlabel(e, FALSE);
+	updateBB(agraphof(agtail(e)), ED_tail_label(e));
+    }
+}
+
+/* endPoints:
+ * Extract the actual end points of the spline, where
+ * they touch the node.
+ */
+static void endPoints(splines * spl, pointf * p, pointf * q)
+{
+    bezier bz;
+
+    bz = spl->list[0];
+    if (bz.sflag) {
+	*p = bz.sp;
+    }
+    else {
+	*p = bz.list[0];
+    }
+    bz = spl->list[spl->size - 1];
+    if (bz.eflag) {
+	*q = bz.ep;
+    }
+    else {
+	*q = bz.list[bz.size - 1];
+    }
+}
+
+/* polylineMidpoint;
+ * Find midpoint of polyline.
+ * pp and pq are set to the endpoints of the line segment containing it.
+ */
+static pointf
+polylineMidpoint (splines* spl, pointf* pp, pointf* pq)
+{
+    bezier bz;
+    int i, j, k;
+    double d, dist = 0;
+    pointf pf, qf, mf;
+
+    for (i = 0; i < spl->size; i++) {
+	bz = spl->list[i];
+	for (j = 0, k=3; k < bz.size; j+=3,k+=3) {
+	    pf = bz.list[j];
+	    qf = bz.list[k];
+	    dist += DIST(pf, qf);
+	}
+    }
+    dist /= 2;
+    for (i = 0; i < spl->size; i++) {
+	bz = spl->list[i];
+	for (j = 0, k=3; k < bz.size; j+=3,k+=3) {
+	    pf = bz.list[j];
+	    qf = bz.list[k];
+	    d = DIST(pf,qf);
+	    if (d >= dist) {
+		*pp = pf;
+		*pq = qf;
+		mf.x = ((qf.x*dist) + (pf.x*(d-dist)))/d; 
+		mf.y = ((qf.y*dist) + (pf.y*(d-dist)))/d; 
+		return mf;
+	    }
+	    else
+		dist -= d;
+	}
+    }
+    assert (FALSE);   /* should never get here */
+    return mf;
+}
+
+#define LEFTOF(a,b,c) (((a.y - b.y)*(c.x - b.x) - (c.y - b.y)*(a.x - b.x)) > 0)
+#define MAXLABELWD  (POINTS_PER_INCH/2.0)
+
+/* addEdgeLabels:
+ * rp and rq are the port points of the tail and head node.
+ * Adds label, headlabel and taillabel.
+ * The use of 2 and 4 in computing ld.x and ld.y are fudge factors, to
+ * introduce a bit of spacing.
+ * Updates bounding box.
+ * We try to use the actual endpoints of the spline, as they may differ
+ * significantly from rp and rq, but if the spline is degenerate (e.g.,
+ * the nodes overlap), we use rp and rq.
+ */
+void addEdgeLabels(graph_t* g, edge_t * e, pointf rp, pointf rq)
+{
+    int et = EDGE_TYPE (g);
+    pointf p, q;
+    pointf d;			/* midpoint of segment p-q */
+    point ld;
+    point del;
+    pointf spf;
+    double f, ht, wd, dist2;
+    int leftOf;
+
+    if (ED_label(e) && !ED_label(e)->set) {
+	endPoints(ED_spl(e), &p, &q);
+        if (APPROXEQPT(p, q, MILLIPOINT)) { /* degenerate spline */
+	    p = rp;
+	    q = rq;
+	    spf = p;
+	}
+	else if (et == ET_SPLINE) {
+	    d.x = (q.x + p.x) / 2.;
+	    d.y = (p.y + q.y) / 2.;
+	    spf = dotneato_closest(ED_spl(e), d);
+	}
+	else {   /* ET_PLINE, ET_ORTHO or ET_LINE */
+	    spf = polylineMidpoint (ED_spl(e), &p, &q);
+	}
+	del.x = q.x - p.x;
+	del.y = q.y - p.y;
+	dist2 = del.x*del.x + del.y*del.y;
+	ht = (ED_label(e)->dimen.y + 2)/2.0;
+	if (dist2) {
+	    wd = (MIN(ED_label(e)->dimen.x + 2, MAXLABELWD))/2.0;
+	    leftOf = LEFTOF(p, q, spf);
+	    if ((leftOf && (del.y >= 0)) || (!leftOf && (del.y < 0))) {
+		if (del.x*del.y >= 0)
+		    ht *= -1;
+	    }
+	    else {
+		wd *= -1;
+		if (del.x*del.y < 0)
+		    ht *= -1;
+	    }
+	    f = (del.y*wd - del.x*ht)/dist2;
+	    ld.x = -f*del.y;
+	    ld.y = f*del.x;
+	}
+	else {    /* end points the same */
+	    ld.x = 0;
+	    ld.y = -ht;
+	}
+
+	ED_label(e)->pos.x = spf.x + ld.x;
+	ED_label(e)->pos.y = spf.y + ld.y;
+	ED_label(e)->set = TRUE;
+	updateBB(agraphof(agtail(e)), ED_label(e));
+    }
+    makePortLabels(e);
+}
+
 /* vladimir */
 void place_portlabel(edge_t * e, boolean head_p)
 /* place the {head,tail}label (depending on HEAD_P) of edge E */