- Real const round = my_round (p);
- Real const frac = p - round;
- if (fabs (frac) < 4 * state.thickness_
- && Staff_symbol_referencer::on_staff_line (staff, int (round)))
+ int round_p = (int) my_round (p);
+ if (!Staff_symbol_referencer::on_staff_line (staff, round_p))
+ round_p += (p > round_p) ? 1 : -1;
+ if (!Staff_symbol_referencer::on_staff_line (staff, round_p))
+ return bez;
+
+ Real const distance = (p - round_p) * state.staff_space_ / 2.0;
+ // Allow half the thickness of the slur at the point t, plus one basic
+ // blot-diameter (half for the slur outline, half for the staff line)
+ Real const min_distance = 0.5 * state.thickness_ * factor
+ + state.line_thickness_
+ + ((state.dir_ * distance > 0.0)
+ ? state.parameters_.gap_to_staffline_inside_
+ : state.parameters_.gap_to_staffline_outside_);
+ if (fabs (distance) < min_distance)