| Index: lily/beam.cc |
| diff --git a/lily/beam.cc b/lily/beam.cc |
| index 0cfc3e193cba6b3feea911abb09a6f9e5118d6c2..f680973e5c288f63addedbc8c0ee8262ce744735 100644 |
| --- a/lily/beam.cc |
| +++ b/lily/beam.cc |
| @@ -1306,36 +1306,39 @@ Beam::rest_collision_callback (SCM smob, SCM prev_offset) |
| return scm_from_double (offset + staff_space * shift); |
| } |
| +/* |
| + Estimate the position of a rest under a beam, |
| + as the average position of its neighboring heads. |
| +*/ |
| MAKE_SCHEME_CALLBACK_WITH_OPTARGS (Beam, pure_rest_collision_callback, 4, 1, ""); |
| SCM |
| Beam::pure_rest_collision_callback (SCM smob, |
| - SCM, /* prev_offset */ |
| SCM, /* start */ |
| - SCM /* end */) |
| + SCM, /* end */ |
| + SCM prev_offset) |
| { |
| - Real amount = 0.0; |
| + Real previous = robust_scm2double (prev_offset, 0.0); |
| Grob *me = unsmob_grob (smob); |
| Grob *stem = unsmob_grob (me->get_object ("stem")); |
| if (!stem) |
| - return scm_from_double (amount); |
| + return scm_from_double (previous); |
| Grob *beam = unsmob_grob (stem->get_object ("beam")); |
| if (!beam |
| || !Beam::normal_stem_count (beam) |
| || !is_direction (beam->get_property_data ("direction"))) |
| - return scm_from_double (amount); |
| + return scm_from_double (previous); |
| Real ss = Staff_symbol_referencer::staff_space (me); |
| /* |
| This gives the extrema of rest positions. |
| - In general, beams are never typeset more than one staff space away |
| - from the staff in either direction. |
| + Even with noteheads on ledgers, beams typically remain within the staff, |
| + and push rests at most one staff-space (2 positions) from the staff. |
| */ |
| Grob *staff = Staff_symbol_referencer::get_staff_symbol (me); |
| Interval rest_max_pos = staff ? Staff_symbol::line_span (staff) : Interval (0.0, 0.0); |
| - rest_max_pos.widen (1); |
| - rest_max_pos *= ss / 2; |
| + rest_max_pos.widen (2); |
| extract_grob_set (beam, "stems", stems); |
| vector<Grob *> my_stems; |
| @@ -1356,7 +1359,7 @@ Beam::pure_rest_collision_callback (SCM smob, |
| Grob *right; |
| if (idx == (vsize) - 1 || my_stems.size () == 1) |
| - return scm_from_double (amount); |
| + return scm_from_double (previous); |
| else if (idx == 0) |
| left = right = my_stems[1]; |
| else if (idx == my_stems.size () - 1) |
| @@ -1366,15 +1369,19 @@ Beam::pure_rest_collision_callback (SCM smob, |
| left = my_stems[idx - 1]; |
| right = my_stems[idx + 1]; |
| } |
| - Direction beamdir = get_grob_direction (beam); |
| - /* |
| - Take the position between the two bounding head_positions, |
| - then bound it by the minimum and maximum positions outside the staff. |
| - 4.0 = 2.0 to get out of staff space * 2.0 for the average |
| - */ |
| - amount = min (max ((Stem::head_positions (left)[beamdir] + Stem::head_positions (right)[beamdir]) / 4.0, rest_max_pos[DOWN]), rest_max_pos[UP]); |
| - return scm_from_double (amount); |
| + /* In stems with several heads, use the one closest to the beam. */ |
| + Direction beamdir = get_grob_direction (beam); |
| + Real shift = min (max ( (Stem::head_positions (left)[beamdir] |
| + + Stem::head_positions (right)[beamdir]) / 2.0, |
| + rest_max_pos[DOWN]), |
| + rest_max_pos[UP] |
| + ) * ss / 2.0 |
| + - previous; |
| + /* Always move by a whole number of staff spaces */ |
| + shift = ceil (fabs (shift / ss)) * ss * sign (shift); |
| + |
| + return scm_from_double (previous + shift); |
| } |
| bool |
