X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Flookup.cc;h=d7b6b8d26e9bc81c5eada2ab7911128c1de26a2d;hb=97a0169312a260933246ab224e4f8b0969871dd5;hp=3e592516c588bc765cdfe451931bd56da2122e8b;hpb=ef9512388b15e1e5e2b3592299ffe489ac43abb4;p=lilypond.git

diff --git a/lily/lookup.cc b/lily/lookup.cc
index 3e592516c5..d7b6b8d26e 100644
--- a/lily/lookup.cc
+++ b/lily/lookup.cc
@@ -417,9 +417,9 @@ Lookup::slur (Bezier curve, Real curvethick, Real linethick,
       calculate the offset for the two beziers that make the sandwich
       for the slur
   */
-  Real alpha = (curve.control_[3] - curve.control_[0]).arg ();
+  Offset dir = (curve.control_[3] - curve.control_[0]).direction ();
   Bezier back = curve;
-  Offset perp = curvethick * complex_exp (Offset (0, alpha + M_PI / 2)) * 0.5;
+  Offset perp = 0.5 * curvethick * Offset (-dir[Y_AXIS], dir[X_AXIS]);
   back.control_[1] += perp;
   back.control_[2] += perp;