X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fbezier.cc;h=b202d45dd6262f5d52df2590bdc2a93846e68579;hb=17378a326b64ebeaeb6f9454cde414923785a470;hp=7d3ad6af14fff2d8d2a24267f6fc9e9b729dff6b;hpb=99b6f3aa3558b01c9d4158b19a1f1794c534f89c;p=lilypond.git

diff --git a/lily/bezier.cc b/lily/bezier.cc
index 7d3ad6af14..b202d45dd6 100644
--- a/lily/bezier.cc
+++ b/lily/bezier.cc
@@ -1,7 +1,7 @@
 /*
   This file is part of LilyPond, the GNU music typesetter.
 
-  Copyright (C) 1998--2014 Jan Nieuwenhuizen <janneke@gnu.org>
+  Copyright (C) 1998--2015 Jan Nieuwenhuizen <janneke@gnu.org>
 
   LilyPond is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -140,8 +140,9 @@ Bezier::curve_point (Real t) const
   return o;
 }
 
-Real
-Bezier::slope_at_point (Real t) const
+// The return value is normalized unless zero or indefinite.
+Offset
+Bezier::dir_at_point (Real t) const
 {
   Offset second_order[3];
   Offset third_order[2];
@@ -152,10 +153,7 @@ Bezier::slope_at_point (Real t) const
   for (vsize i = 0; i < 2; i++)
     third_order[i] = ((second_order[i + 1] - second_order[i]) * t) + second_order[i];
 
-  if (third_order[1][X_AXIS] - third_order[0][X_AXIS] == 0)
-    return infinity_f;
-
-  return (third_order[1][Y_AXIS] - third_order[0][Y_AXIS]) / (third_order[1][X_AXIS] - third_order[0][X_AXIS]);
+  return (third_order[1] - third_order[0]).direction ();
 }
 
 /*