Finish orthogonal case where edge has head and tail arrows on a single line segment

diff --git a/lib/common/arrows.c b/lib/common/arrows.c
index 80984d544e8b4621d46dd7bd0445fef36767da4a..58046bb249b029df89aad4843b875b6a1405224e 100644 (file)
--- a/lib/common/arrows.c
+++ b/lib/common/arrows.c
@@ -316,18 +316,44 @@ int arrowStartClip(edge_t* e, pointf * ps, int startp,
  */
 void arrowOrthoClip(edge_t* e, pointf* ps, int startp, int endp, bezier* spl, int sflag, int eflag)
 {
-    pointf p, q, r;
+    pointf p, q, r, s, t;
     double d, tlen, hlen, maxd;
 
     if (sflag && eflag && (endp == startp)) { /* handle special case of two arrows on a single segment */
+       p = ps[endp];
+       q = ps[endp+3];
        tlen = arrow_length (e, sflag);
        hlen = arrow_length (e, eflag);
-        d = DIST(ps[endp], ps[endp + 3]);
-       if (hlen + tlen < d) {
-           spl->eflag = eflag, spl->ep = ps[endp + 3];
+        d = DIST(p, q);
+       if (hlen + tlen >= d) {
+           hlen = tlen = d/3.0;
+       }
+       if (p.y == q.y) { /* horz segment */
+           s.y = t.y = p.y;
+           if (p.x < q.x) {
+               t.x = q.x - hlen;
+               s.x = p.x + tlen;
+           }
+           else {
+               t.x = q.x + hlen;
+               s.x = p.x - tlen;
+           }
        }
-       else {
+       else {            /* vert segment */
+           s.x = t.x = p.x;
+           if (p.y < q.y) {
+               t.y = q.y - hlen;
+               s.y = p.y + tlen;
+           }
+           else {
+               t.y = q.y + hlen;
+               s.y = p.y - tlen;
+           }
        }
+       ps[endp] = ps[endp + 1] = s;
+       ps[endp + 2] = ps[endp + 3] = t;
+       spl->eflag = eflag, spl->ep = p;
+       spl->sflag = sflag, spl->ep = q;
        return;
     }
     if (eflag) {