2 beam.cc -- implement Beam
4 source file of the GNU LilyPond music typesetter
6 (c) 1997--2006 Han-Wen Nienhuys <hanwen@xs4all.nl>
7 Jan Nieuwenhuizen <janneke@gnu.org>
13 - Determine auto knees based on positions if it's set by the user.
15 - the code is littered with * and / staff_space calls for
16 #'positions. Consider moving to real-world coordinates?
18 Problematic issue is user tweaks (user tweaks are in staff-coordinates.)
22 - Stems run to the Y-center of the beam.
24 - beam_translation is the offset between Y centers of the beam.
29 #include "beaming-pattern.hh"
30 #include "directional-element-interface.hh"
32 #include "international.hh"
33 #include "interval-set.hh"
35 #include "least-squares.hh"
38 #include "output-def.hh"
39 #include "pointer-group-interface.hh"
41 #include "staff-symbol-referencer.hh"
45 #if DEBUG_BEAM_SCORING
46 #include "text-interface.hh" // debug output.
47 #include "font-interface.hh" // debug output.
53 Beam_stem_segment::Beam_stem_segment ()
55 max_connect_ = 1000; // infinity
64 Beam_segment::Beam_segment ()
70 Beam::add_stem (Grob *me, Grob *s)
72 if (Stem::get_beam (s))
74 programming_error ("Stem already has beam");
78 Pointer_group_interface::add_grob (me, ly_symbol2scm ("stems"), s);
79 s->set_object ("beam", me->self_scm ());
80 add_bound_item (dynamic_cast<Spanner *> (me), dynamic_cast<Item *> (s));
84 Beam::get_thickness (Grob *me)
86 return robust_scm2double (me->get_property ("thickness"), 0)
87 * Staff_symbol_referencer::staff_space (me);
90 /* Return the translation between 2 adjoining beams. */
92 Beam::get_beam_translation (Grob *me)
94 int beam_count = get_beam_count (me);
95 Real staff_space = Staff_symbol_referencer::staff_space (me);
96 Real line = Staff_symbol_referencer::line_thickness (me);
97 Real thickness = get_thickness (me);
98 Real fract = robust_scm2double (me->get_property ("length-fraction"), 1.0);
100 Real beam_translation = beam_count < 4
101 ? (2 * staff_space + line - thickness) / 2.0
102 : (3 * staff_space + line - thickness) / 3.0;
104 return fract * beam_translation;
107 /* Maximum beam_count. */
109 Beam::get_beam_count (Grob *me)
113 extract_grob_set (me, "stems", stems);
114 for (vsize i = 0; i < stems.size (); i++)
116 Grob *stem = stems[i];
117 m = max (m, (Stem::beam_multiplicity (stem).length () + 1));
123 MAKE_SCHEME_CALLBACK (Beam, calc_direction, 1);
125 Beam::calc_direction (SCM smob)
127 Grob *me = unsmob_grob (smob);
129 /* Beams with less than 2 two stems don't make much sense, but could happen
136 Direction dir = CENTER;
138 int count = visible_stem_count (me);
141 extract_grob_set (me, "stems", stems);
142 if (stems.size () == 0)
144 me->warning (_ ("removing beam with no stems"));
147 return SCM_UNSPECIFIED;
151 Grob *stem = first_visible_stem (me);
154 ugh: stems[0] case happens for chord tremolo.
156 dir = to_dir ((stem ? stem : stems[0])->get_property ("default-direction"));
163 dir = get_default_dir (me);
165 consider_auto_knees (me);
170 set_stem_directions (me, dir);
173 return scm_from_int (dir);
178 /* We want a maximal number of shared beams, but if there is choice, we
179 * take the one that is closest to the end of the stem. This is for
191 position_with_maximal_common_beams (SCM left_beaming, SCM right_beaming,
195 Slice lslice = int_list_to_slice (scm_cdr (left_beaming));
199 for (int i = lslice[-left_dir];
200 (i - lslice[left_dir]) * left_dir <= 0; i += left_dir)
203 for (SCM s = scm_car (right_beaming); scm_is_pair (s); s = scm_cdr (s))
205 int k = -right_dir * scm_to_int (scm_car (s)) + i;
206 if (scm_c_memq (scm_from_int (k), left_beaming) != SCM_BOOL_F)
210 if (count >= best_count)
220 MAKE_SCHEME_CALLBACK(Beam, calc_beaming, 1)
222 Beam::calc_beaming (SCM smob)
224 Grob *me = unsmob_grob (smob);
226 extract_grob_set (me, "stems", stems);
229 last_int.set_empty ();
231 SCM last_beaming = scm_cons (SCM_EOL, scm_list_1 (scm_from_int (0)));
232 Direction last_dir = CENTER;
233 for (vsize i = 0; i < stems.size (); i++)
235 Grob *this_stem = stems[i];
236 SCM this_beaming = this_stem->get_property ("beaming");
238 Direction this_dir = get_grob_direction (this_stem);
239 if (scm_is_pair (last_beaming) && scm_is_pair (this_beaming))
241 int start_point = position_with_maximal_common_beams
242 (last_beaming, this_beaming,
243 last_dir ? last_dir : this_dir,
250 new_slice.set_empty ();
251 SCM s = index_get_cell (this_beaming, d);
252 for (; scm_is_pair (s); s = scm_cdr (s))
255 = start_point - this_dir * scm_to_int (scm_car (s));
257 new_slice.add_point (new_beam_pos);
258 scm_set_car_x (s, scm_from_int (new_beam_pos));
261 while (flip (&d) != LEFT);
263 if (!new_slice.is_empty ())
264 last_int = new_slice;
268 SCM s = scm_cdr (this_beaming);
269 for (; scm_is_pair (s); s = scm_cdr (s))
271 int np = -this_dir * scm_to_int (scm_car (s));
272 scm_set_car_x (s, scm_from_int (np));
273 last_int.add_point (np);
277 if (scm_ilength (scm_cdr (this_beaming)) > 0)
279 last_beaming = this_beaming;
288 operator <(Beam_stem_segment const &a,
289 Beam_stem_segment const &b)
291 return a.rank_ < b.rank_;
294 typedef map<int, vector<Beam_stem_segment> > Position_stem_segments_map;
297 Beam::get_beam_segments (Grob *me_grob, Grob **common)
299 Spanner *me = dynamic_cast<Spanner*> (me_grob);
301 extract_grob_set (me, "stems", stems);
302 Grob *commonx = common_refpoint_of_array (stems, me, X_AXIS);
304 commonx = me->get_bound (LEFT)->common_refpoint (commonx, X_AXIS);
305 commonx = me->get_bound (RIGHT)->common_refpoint (commonx, X_AXIS);
309 int gap_count = robust_scm2int (me->get_property ("gap-count"), 0);
310 Real gap_length = robust_scm2double (me->get_property ("gap"), 0.0);
312 Position_stem_segments_map stem_segments;
313 Real lt = me->layout ()->get_dimension (ly_symbol2scm ("line-thickness"));
317 for (vsize i = 0; i < stems.size (); i++)
319 Grob *stem = stems[i];
320 Real stem_width = robust_scm2double (stem->get_property ("thickness"), 1.0) * lt;
321 Real stem_x = stem->relative_coordinate (commonx, X_AXIS);
322 SCM beaming = stem->get_property ("beaming");
326 for (SCM s = index_get_cell (beaming, d);
327 scm_is_pair (s); s = scm_cdr (s))
329 if (!scm_is_integer (scm_car (s)))
332 int beam_rank = scm_to_int (scm_car (s));
333 ranks.add_point (beam_rank);
336 for (SCM s = index_get_cell (beaming, d);
337 scm_is_pair (s); s = scm_cdr (s))
339 if (!scm_is_integer (scm_car (s)))
342 int beam_rank = scm_to_int (scm_car (s));
343 Beam_stem_segment seg;
345 seg.stem_x_ = stem_x;
346 seg.rank_ = 2 * i + (d+1)/2;
347 seg.width_ = stem_width;
350 seg.max_connect_ = robust_scm2int (stem->get_property ("max-beam-connect"), 1000);
352 Direction stem_dir = get_grob_direction (stem);
355 = (stem_dir * beam_rank < (stem_dir * ranks[-stem_dir] + gap_count));
356 stem_segments[beam_rank].push_back (seg);
359 while (flip (&d) != LEFT);
362 Drul_array<Real> break_overshoot
363 = robust_scm2drul (me->get_property ("break-overshoot"),
364 Drul_array<Real> (-0.5, 0.0));
366 vector<Beam_segment> segments;
367 for (Position_stem_segments_map::const_iterator i (stem_segments.begin ());
368 i != stem_segments.end (); i++)
370 vector<Beam_stem_segment> segs = (*i).second;
371 vector_sort (segs, less<Beam_stem_segment> ());
373 Beam_segment current;
375 int vertical_count = (*i).first;
376 for (vsize j = 0; j < segs.size (); j++)
379 event_dir == LEFT: left edge of a beamsegment.
381 Direction event_dir = LEFT;
384 Drul_array<bool> on_bound (j == 0 && event_dir==LEFT,
385 j == segs.size() - 1 && event_dir==RIGHT);
386 Drul_array<bool> inside (j > 0, j < segs.size()-1);
387 bool event = on_bound[event_dir]
388 || abs (segs[j].rank_ - segs[j+event_dir].rank_) > 1
389 || (abs (vertical_count) >= segs[j].max_connect_
390 || abs (vertical_count) >= segs[j + event_dir].max_connect_);
395 current.vertical_count_ = vertical_count;
396 current.horizontal_[event_dir] = segs[j].stem_x_;
397 if (segs[j].dir_ == event_dir)
399 if (on_bound[event_dir]
400 && me->get_bound (event_dir)->break_status_dir ())
402 current.horizontal_[event_dir]
403 = (me->get_bound (event_dir)->extent (commonx, X_AXIS)[RIGHT]
404 + event_dir * break_overshoot[event_dir]);
408 Real notehead_width =
409 Stem::duration_log (segs[j].stem_) == 1
413 if (inside[event_dir])
414 notehead_width = min (notehead_width,
415 fabs (segs[j+ event_dir].stem_x_
416 - segs[j].stem_x_)/2);
418 current.horizontal_[event_dir] += event_dir * notehead_width;
423 current.horizontal_[event_dir] += event_dir * segs[j].width_/2;
425 current.horizontal_[event_dir] -= event_dir * gap_length;
428 if (event_dir == RIGHT)
430 segments.push_back (current);
431 current = Beam_segment();
434 while (flip (&event_dir) != LEFT);
442 MAKE_SCHEME_CALLBACK(Beam, print, 1);
444 Beam::print (SCM grob)
446 Spanner *me = unsmob_spanner (grob);
448 vector<Beam_segment> segments = get_beam_segments (me, &commonx);
451 if (visible_stem_count (me))
453 span[LEFT] = first_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
454 span[RIGHT] = last_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
458 extract_grob_set (me, "stems", stems);
459 span[LEFT] = stems[0]->relative_coordinate (commonx, X_AXIS);
460 span[RIGHT] = stems.back ()->relative_coordinate (commonx, X_AXIS);
463 Real blot = me->layout ()->get_dimension (ly_symbol2scm ("blot-diameter"));
465 SCM posns = me->get_property ("quantized-positions");
467 if (!is_number_pair (posns))
469 programming_error ("no beam positions?");
470 pos = Interval (0, 0);
473 pos = ly_scm2realdrul (posns);
475 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
477 Real dy = pos[RIGHT] - pos[LEFT];
478 Real slope = (dy && span.length ()) ? dy / span.length () : 0;
480 Real thick = get_thickness (me);
481 Real beam_dy = get_beam_translation (me);
483 Direction feather_dir = to_dir (me->get_property ("grow-direction"));
486 for (vsize i = 0; i < segments.size (); i ++)
488 Real local_slope = slope;
491 local_slope += feather_dir * segments[i].vertical_count_ * beam_dy / span.length ();
494 Stencil b = Lookup::beam (local_slope, segments[i].horizontal_.length (), thick, blot);
496 b.translate_axis (segments[i].horizontal_[LEFT], X_AXIS);
498 b.translate_axis (local_slope
499 * (segments[i].horizontal_[LEFT] - span.linear_combination (feather_dir))
500 + pos.linear_combination (feather_dir)
501 + beam_dy * segments[i].vertical_count_, Y_AXIS);
502 the_beam.add_stencil (b);
505 #if (DEBUG_BEAM_SCORING)
506 SCM quant_score = me->get_property ("quant-score");
507 SCM debug = me->layout ()->lookup_variable (ly_symbol2scm ("debug-beam-scoring"));
508 if (to_boolean (debug) && scm_is_string (quant_score))
510 extract_grob_set (me, "stems", stems);
513 This code prints the demerits for each beam. Perhaps this
514 should be switchable for those who want to twiddle with the
518 SCM properties = Font_interface::text_font_alist_chain (me);
520 Direction stem_dir = stems.size () ? to_dir (stems[0]->get_property ("direction")) : UP;
522 Stencil score = *unsmob_stencil (Text_interface::interpret_markup
523 (me->layout ()->self_scm (), properties, quant_score));
525 if (!score.is_empty ())
526 the_beam.add_at_edge (Y_AXIS, stem_dir, score, 1.0, 0);
530 the_beam.translate_axis (-me->relative_coordinate (commonx, X_AXIS), X_AXIS);
531 return the_beam.smobbed_copy ();
535 Beam::get_default_dir (Grob *me)
537 extract_grob_set (me, "stems", stems);
539 Drul_array<Real> extremes (0.0, 0.0);
540 for (iterof (s, stems); s != stems.end (); s++)
542 Interval positions = Stem::head_positions (*s);
546 if (sign (positions[d]) == d)
547 extremes[d] = d * max (d * positions[d], d * extremes[d]);
549 while (flip (&d) != DOWN);
552 Drul_array<int> total (0, 0);
553 Drul_array<int> count (0, 0);
555 bool force_dir = false;
556 for (vsize i = 0; i < stems.size (); i++)
559 Direction stem_dir = CENTER;
560 SCM stem_dir_scm = s->get_property_data ("direction");
561 if (is_direction (stem_dir_scm))
563 stem_dir = to_dir (stem_dir_scm);
567 stem_dir = to_dir (s->get_property ("default-direction"));
570 stem_dir = to_dir (s->get_property ("neutral-direction"));
575 total[stem_dir] += max (int (- stem_dir * Stem::head_positions (s) [-stem_dir]), 0);
582 if (abs (extremes[UP]) > -extremes[DOWN])
584 else if (extremes[UP] < -extremes[DOWN])
588 Direction dir = CENTER;
589 Direction d = CENTER;
590 if ((d = (Direction) sign (count[UP] - count[DOWN])))
594 && (d = (Direction) sign (total[UP] / count[UP] - total[DOWN]/count[DOWN])))
596 else if ((d = (Direction) sign (total[UP] - total[DOWN])))
599 dir = to_dir (me->get_property ("neutral-direction"));
604 /* Set all stems with non-forced direction to beam direction.
605 Urg: non-forced should become `without/with unforced' direction,
606 once stem gets cleaned-up. */
608 Beam::set_stem_directions (Grob *me, Direction d)
610 extract_grob_set (me, "stems", stems);
612 for (vsize i = 0; i < stems.size (); i++)
616 SCM forcedir = s->get_property_data ("direction");
617 if (!to_dir (forcedir))
618 set_grob_direction (s, d);
623 Only try horizontal beams for knees. No reliable detection of
624 anything else is possible here, since we don't know funky-beaming
625 settings, or X-distances (slopes!) People that want sloped
626 knee-beams, should set the directions manually.
631 this routine should take into account the stemlength scoring
632 of a possible knee/nonknee beam.
635 Beam::consider_auto_knees (Grob *me)
637 SCM scm = me->get_property ("auto-knee-gap");
638 if (!scm_is_number (scm))
645 extract_grob_set (me, "stems", stems);
647 Grob *common = common_refpoint_of_array (stems, me, Y_AXIS);
648 Real staff_space = Staff_symbol_referencer::staff_space (me);
650 vector<Interval> head_extents_array;
651 for (vsize i = 0; i < stems.size (); i++)
653 Grob *stem = stems[i];
654 if (Stem::is_invisible (stem))
657 Interval head_extents = Stem::head_positions (stem);
658 if (!head_extents.is_empty ())
660 head_extents[LEFT] += -1;
661 head_extents[RIGHT] += 1;
662 head_extents *= staff_space * 0.5;
665 We could subtract beam Y position, but this routine only
666 sets stem directions, a constant shift does not have an
669 head_extents += stem->relative_coordinate (common, Y_AXIS);
671 if (to_dir (stem->get_property_data ("direction")))
673 Direction stemdir = to_dir (stem->get_property ("direction"));
674 head_extents[-stemdir] = -stemdir * infinity_f;
677 head_extents_array.push_back (head_extents);
679 gaps.remove_interval (head_extents);
683 Real max_gap_len = 0.0;
685 for (vsize i = gaps.allowed_regions_.size () -1; i != VPOS ;i--)
687 Interval gap = gaps.allowed_regions_[i];
690 the outer gaps are not knees.
692 if (isinf (gap[LEFT]) || isinf (gap[RIGHT]))
695 if (gap.length () >= max_gap_len)
697 max_gap_len = gap.length ();
702 Real beam_translation = get_beam_translation (me);
703 Real beam_thickness = Beam::get_thickness (me);
704 int beam_count = Beam::get_beam_count (me);
705 Real height_of_beams = beam_thickness / 2
706 + (beam_count - 1) * beam_translation;
707 Real threshold = scm_to_double (scm) + height_of_beams;
709 if (max_gap_len > threshold)
712 for (vsize i = 0; i < stems.size (); i++)
714 Grob *stem = stems[i];
715 if (Stem::is_invisible (stem))
718 Interval head_extents = head_extents_array[j++];
720 Direction d = (head_extents.center () < max_gap.center ())
723 stem->set_property ("direction", scm_from_int (d));
725 head_extents.intersect (max_gap);
726 assert (head_extents.is_empty () || head_extents.length () < 1e-6);
731 /* Set stem's shorten property if unset.
734 take some y-position (chord/beam/nearest?) into account
735 scmify forced-fraction
737 This is done in beam because the shorten has to be uniform over the
744 set_minimum_dy (Grob *me, Real *dy)
749 If dy is smaller than the smallest quant, we
750 get absurd direction-sign penalties.
753 Real ss = Staff_symbol_referencer::staff_space (me);
754 Real thickness = Beam::get_thickness (me) / ss;
755 Real slt = Staff_symbol_referencer::line_thickness (me) / ss;
756 Real sit = (thickness - slt) / 2;
758 Real hang = 1.0 - (thickness - slt) / 2;
760 *dy = sign (*dy) * max (fabs (*dy),
761 min (min (sit, inter), hang));
767 MAKE_SCHEME_CALLBACK(Beam, calc_stem_shorten, 1)
769 Beam::calc_stem_shorten (SCM smob)
771 Grob *me = unsmob_grob (smob);
774 shortening looks silly for x staff beams
777 return scm_from_int (0);
779 Real forced_fraction = 1.0 * forced_stem_count (me)
780 / visible_stem_count (me);
782 int beam_count = get_beam_count (me);
784 SCM shorten_list = me->get_property ("beamed-stem-shorten");
785 if (shorten_list == SCM_EOL)
786 return scm_from_int (0);
788 Real staff_space = Staff_symbol_referencer::staff_space (me);
791 = robust_list_ref (beam_count -1, shorten_list);
792 Real shorten = scm_to_double (shorten_elt) * staff_space;
794 shorten *= forced_fraction;
798 return scm_from_double (shorten);
800 return scm_from_double (0.0);
806 Compute a first approximation to the beam slope.
808 MAKE_SCHEME_CALLBACK (Beam, calc_least_squares_positions, 2);
810 Beam::calc_least_squares_positions (SCM smob, SCM posns)
814 Grob *me = unsmob_grob (smob);
816 int count = visible_stem_count (me);
819 return ly_interval2scm (pos);
821 vector<Real> x_posns;
822 extract_grob_set (me, "stems", stems);
823 Grob *commonx = common_refpoint_of_array (stems, me, X_AXIS);
824 Grob *commony = common_refpoint_of_array (stems, me, Y_AXIS);
826 Real my_y = me->relative_coordinate (commony, Y_AXIS);
828 Grob *fvs = first_visible_stem (me);
829 Grob *lvs = last_visible_stem (me);
831 Interval ideal (Stem::get_stem_info (fvs).ideal_y_
832 + fvs->relative_coordinate (commony, Y_AXIS) - my_y,
833 Stem::get_stem_info (lvs).ideal_y_
834 + lvs->relative_coordinate (commony, Y_AXIS) - my_y);
836 Real x0 = first_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
837 for (vsize i = 0; i < stems.size (); i++)
841 Real x = s->relative_coordinate (commonx, X_AXIS) - x0;
842 x_posns.push_back (x);
844 Real dx = last_visible_stem (me)->relative_coordinate (commonx, X_AXIS) - x0;
852 Interval chord (Stem::chord_start_y (first_visible_stem (me)),
853 Stem::chord_start_y (last_visible_stem (me)));
855 /* Simple beams (2 stems) on middle line should be allowed to be
858 However, if both stems reach middle line,
859 ideal[LEFT] == ideal[RIGHT] and ideal.delta () == 0.
861 For that case, we apply artificial slope */
862 if (!ideal[LEFT] && chord.delta () && count == 2)
865 Direction d = (Direction) (sign (chord.delta ()) * UP);
866 pos[d] = get_thickness (me) / 2;
873 For broken beams this doesn't work well. In this case, the
874 slope esp. of the first part of a broken beam should predict
875 where the second part goes.
877 ldy = pos[RIGHT] - pos[LEFT];
881 vector<Offset> ideals;
882 for (vsize i = 0; i < stems.size (); i++)
885 if (Stem::is_invisible (s))
887 ideals.push_back (Offset (x_posns[i],
888 Stem::get_stem_info (s).ideal_y_
889 + s->relative_coordinate (commony, Y_AXIS)
893 minimise_least_squares (&slope, &y, ideals);
897 set_minimum_dy (me, &dy);
900 pos = Interval (y, (y + dy));
904 "position" is relative to the staff.
906 scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
908 me->set_property ("least-squares-dy", scm_from_double (ldy));
909 return ly_interval2scm (pos);
913 We can't combine with previous function, since check concave and
914 slope damping comes first.
916 TODO: we should use the concaveness to control the amount of damping
919 MAKE_SCHEME_CALLBACK (Beam, shift_region_to_valid, 2);
921 Beam::shift_region_to_valid (SCM grob, SCM posns)
923 Grob *me = unsmob_grob (grob);
927 vector<Real> x_posns;
928 extract_grob_set (me, "stems", stems);
929 Grob *commonx = common_refpoint_of_array (stems, me, X_AXIS);
930 Grob *commony = common_refpoint_of_array (stems, me, Y_AXIS);
932 Grob *fvs = first_visible_stem (me);
937 Real x0 = fvs->relative_coordinate (commonx, X_AXIS);
938 for (vsize i = 0; i < stems.size (); i++)
942 Real x = s->relative_coordinate (commonx, X_AXIS) - x0;
943 x_posns.push_back (x);
946 Grob *lvs = last_visible_stem (me);
950 Real dx = lvs->relative_coordinate (commonx, X_AXIS) - x0;
952 Drul_array<Real> pos = ly_scm2interval (posns);
955 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
957 Real dy = pos[RIGHT] - pos[LEFT];
959 Real slope = dx ? (dy / dx) : 0.0;
962 Shift the positions so that we have a chance of finding good
963 quants (i.e. no short stem failures.)
965 Interval feasible_left_point;
966 feasible_left_point.set_full ();
967 for (vsize i = 0; i < stems.size (); i++)
970 if (Stem::is_invisible (s))
973 Direction d = get_grob_direction (s);
976 = Stem::get_stem_info (s).shortest_y_
977 - slope * x_posns [i];
980 left_y is now relative to the stem S. We want relative to
981 ourselves, so translate:
984 += + s->relative_coordinate (commony, Y_AXIS)
985 - me->relative_coordinate (commony, Y_AXIS);
991 feasible_left_point.intersect (flp);
994 if (feasible_left_point.is_empty ())
995 warning (_ ("no viable initial configuration found: may not find good beam slope"));
996 else if (!feasible_left_point.contains (y))
998 const int REGION_SIZE = 2; // UGH UGH
999 if (isinf (feasible_left_point[DOWN]))
1000 y = feasible_left_point[UP] - REGION_SIZE;
1001 else if (isinf (feasible_left_point[UP]))
1002 y = feasible_left_point[DOWN]+ REGION_SIZE;
1004 y = feasible_left_point.center ();
1007 pos = Drul_array<Real> (y, (y + dy));
1008 scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
1010 return ly_interval2scm (pos);
1013 /* This neat trick is by Werner Lemberg,
1014 damped = tanh (slope)
1015 corresponds with some tables in [Wanske] CHECKME */
1016 MAKE_SCHEME_CALLBACK (Beam, slope_damping, 2);
1018 Beam::slope_damping (SCM smob, SCM posns)
1020 Grob *me = unsmob_grob (smob);
1021 Drul_array<Real> pos = ly_scm2interval (posns);
1023 if (visible_stem_count (me) <= 1)
1027 SCM s = me->get_property ("damping");
1028 Real damping = scm_to_double (s);
1029 Real concaveness = robust_scm2double (me->get_property ("concaveness"), 0.0);
1030 if (concaveness >= 10000)
1032 pos[LEFT] = pos[RIGHT];
1033 me->set_property ("least-squares-dy", scm_from_double (0));
1039 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
1041 Real dy = pos[RIGHT] - pos[LEFT];
1043 Grob *fvs = first_visible_stem (me);
1044 Grob *lvs = last_visible_stem (me);
1046 Grob *commonx = fvs->common_refpoint (lvs, X_AXIS);
1048 Real dx = last_visible_stem (me)->relative_coordinate (commonx, X_AXIS)
1049 - first_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
1051 Real slope = dy && dx ? dy / dx : 0;
1053 slope = 0.6 * tanh (slope) / (damping + concaveness);
1055 Real damped_dy = slope * dx;
1057 set_minimum_dy (me, &damped_dy);
1059 pos[LEFT] += (dy - damped_dy) / 2;
1060 pos[RIGHT] -= (dy - damped_dy) / 2;
1062 scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
1065 return ly_interval2scm (pos);
1069 Report slice containing the numbers that are both in (car BEAMING)
1073 where_are_the_whole_beams (SCM beaming)
1077 for (SCM s = scm_car (beaming); scm_is_pair (s); s = scm_cdr (s))
1079 if (scm_c_memq (scm_car (s), scm_cdr (beaming)) != SCM_BOOL_F)
1081 l.add_point (scm_to_int (scm_car (s)));
1087 /* Return the Y position of the stem-end, given the Y-left, Y-right
1088 in POS for stem S. This Y position is relative to S. */
1090 Beam::calc_stem_y (Grob *me, Grob *stem, Grob **common,
1092 Drul_array<Real> pos, bool french)
1094 Real beam_translation = get_beam_translation (me);
1096 Real r = stem->relative_coordinate (common[X_AXIS], X_AXIS) - xl;
1097 Real dy = pos[RIGHT] - pos[LEFT];
1099 Real stem_y_beam0 = (dy && dx
1104 Direction my_dir = get_grob_direction (stem);
1105 SCM beaming = stem->get_property ("beaming");
1107 Real stem_y = stem_y_beam0;
1110 Slice bm = where_are_the_whole_beams (beaming);
1111 if (!bm.is_empty ())
1112 stem_y += beam_translation * bm[-my_dir];
1116 Slice bm = Stem::beam_multiplicity (stem);
1117 if (!bm.is_empty ())
1118 stem_y += bm[my_dir] * beam_translation;
1121 Real id = me->relative_coordinate (common[Y_AXIS], Y_AXIS)
1122 - stem->relative_coordinate (common[Y_AXIS], Y_AXIS);
1128 Hmm. At this time, beam position and slope are determined. Maybe,
1129 stem directions and length should set to relative to the chord's
1130 position of the beam. */
1131 MAKE_SCHEME_CALLBACK(Beam, set_stem_lengths, 1);
1133 Beam::set_stem_lengths (SCM smob)
1135 Grob *me = unsmob_grob (smob);
1137 /* trigger callbacks. */
1138 (void) me->get_property ("direction");
1139 (void) me->get_property ("beaming");
1141 SCM posns = me->get_property ("positions");
1143 extract_grob_set (me, "stems", stems);
1148 for (int a = 2; a--;)
1149 common[a] = common_refpoint_of_array (stems, me, Axis (a));
1151 Drul_array<Real> pos = ly_scm2realdrul (posns);
1152 Real staff_space = Staff_symbol_referencer::staff_space (me);
1153 scale_drul (&pos, staff_space);
1157 if (robust_scm2int (me->get_property ("gap-count"), 0))
1160 thick = get_thickness (me);
1163 Grob *fvs = first_visible_stem (me);
1164 Grob *lvs = last_visible_stem (me);
1166 Real xl = fvs ? fvs->relative_coordinate (common[X_AXIS], X_AXIS) : 0.0;
1167 Real xr = lvs ? lvs->relative_coordinate (common[X_AXIS], X_AXIS) : 0.0;
1169 for (vsize i = 0; i < stems.size (); i++)
1173 bool french = to_boolean (s->get_property ("french-beaming"));
1174 Real stem_y = calc_stem_y (me, s, common,
1176 pos, french && s != lvs && s!= fvs);
1179 Make the stems go up to the end of the beam. This doesn't matter
1180 for normal beams, but for tremolo beams it looks silly otherwise.
1183 && !Stem::is_invisible (s))
1184 stem_y += thick * 0.5 * get_grob_direction (s);
1187 Do set_stemend for invisible stems too, so tuplet brackets
1188 have a reference point for sloping
1190 Stem::set_stemend (s, 2 * stem_y / staff_space);
1197 Beam::set_beaming (Grob *me, Beaming_pattern const *beaming)
1199 extract_grob_set (me, "stems", stems);
1202 for (vsize i = 0; i < stems.size (); i++)
1205 Don't overwrite user settings.
1209 Grob *stem = stems[i];
1210 SCM beaming_prop = stem->get_property ("beaming");
1211 if (beaming_prop == SCM_EOL
1212 || index_get_cell (beaming_prop, d) == SCM_EOL)
1214 int count = beaming->beamlet_count (i, d);
1216 && i < stems.size () -1
1217 && Stem::is_invisible (stem))
1218 count = min (count, beaming->beamlet_count (i,-d));
1220 if ( ((i == 0 && d == LEFT)
1221 || (i == stems.size ()-1 && d == RIGHT))
1222 && stems.size () > 1
1223 && to_boolean (me->get_property ("clip-edges")))
1226 Stem::set_beaming (stem, count, d);
1229 while (flip (&d) != LEFT);
1234 Beam::forced_stem_count (Grob *me)
1236 extract_grob_set (me, "stems", stems);
1239 for (vsize i = 0; i < stems.size (); i++)
1243 if (Stem::is_invisible (s))
1246 /* I can imagine counting those boundaries as a half forced stem,
1247 but let's count them full for now. */
1248 Direction defdir = to_dir (s->get_property ("default-direction"));
1250 if (abs (Stem::chord_start_y (s)) > 0.1
1252 && get_grob_direction (s) != defdir)
1259 Beam::visible_stem_count (Grob *me)
1261 extract_grob_set (me, "stems", stems);
1263 for (vsize i = stems.size (); i--;)
1265 if (!Stem::is_invisible (stems[i]))
1272 Beam::first_visible_stem (Grob *me)
1274 extract_grob_set (me, "stems", stems);
1276 for (vsize i = 0; i < stems.size (); i++)
1278 if (!Stem::is_invisible (stems[i]))
1285 Beam::last_visible_stem (Grob *me)
1287 extract_grob_set (me, "stems", stems);
1289 for (vsize i = stems.size (); i--;)
1291 if (!Stem::is_invisible (stems[i]))
1300 handle rest under beam (do_post: beams are calculated now)
1301 what about combination of collisions and rest under beam.
1305 rest -> stem -> beam -> interpolate_y_position ()
1307 MAKE_SCHEME_CALLBACK_WITH_OPTARGS (Beam, rest_collision_callback, 2, 1);
1309 Beam::rest_collision_callback (SCM smob, SCM prev_offset)
1311 Grob *rest = unsmob_grob (smob);
1312 if (scm_is_number (rest->get_property ("staff-position")))
1313 return scm_from_int (0);
1315 Real offset = robust_scm2double (prev_offset, 0.0);
1317 Grob *st = unsmob_grob (rest->get_object ("stem"));
1320 return scm_from_double (0.0);
1321 Grob *beam = unsmob_grob (stem->get_object ("beam"));
1323 || !Beam::has_interface (beam)
1324 || !Beam::visible_stem_count (beam))
1325 return scm_from_double (0.0);
1327 Drul_array<Real> pos (0, 0);
1328 SCM s = beam->get_property ("positions");
1329 if (scm_is_pair (s) && scm_is_number (scm_car (s)))
1330 pos = ly_scm2interval (s);
1332 programming_error ("positions property should always be pair of numbers.");
1334 Real staff_space = Staff_symbol_referencer::staff_space (rest);
1336 scale_drul (&pos, staff_space);
1338 Real dy = pos[RIGHT] - pos[LEFT];
1340 Drul_array<Grob*> visible_stems (first_visible_stem (beam),
1341 last_visible_stem (beam));
1342 extract_grob_set (beam, "stems", stems);
1344 Grob *common = common_refpoint_of_array (stems, beam, X_AXIS);
1346 Real x0 = visible_stems[LEFT]->relative_coordinate (common, X_AXIS);
1347 Real dx = visible_stems[RIGHT]->relative_coordinate (common, X_AXIS) - x0;
1348 Real slope = dy && dx ? dy / dx : 0;
1350 Direction d = get_grob_direction (stem);
1351 Real stem_y = pos[LEFT]
1352 + (stem->relative_coordinate (common, X_AXIS) - x0) * slope;
1354 Real beam_translation = get_beam_translation (beam);
1355 Real beam_thickness = Beam::get_thickness (beam);
1358 TODO: this is not strictly correct for 16th knee beams.
1361 = Stem::beam_multiplicity (stem).length () + 1;
1363 Real height_of_my_beams = beam_thickness / 2
1364 + (beam_count - 1) * beam_translation;
1365 Real beam_y = stem_y - d * height_of_my_beams;
1367 Grob *common_y = rest->common_refpoint (beam, Y_AXIS);
1368 Interval rest_extent = rest->extent (common_y, Y_AXIS);
1369 rest_extent.translate (offset);
1371 Real rest_dim = rest_extent[d];
1372 Real minimum_distance
1373 = staff_space * (robust_scm2double (stem->get_property ("stemlet-length"), 0.0)
1374 + robust_scm2double (rest->get_property ("minimum-distance"), 0.0));
1376 Real shift = d * min (((beam_y - d * minimum_distance) - rest_dim) * d, 0.0);
1378 shift /= staff_space;
1379 Real rad = Staff_symbol_referencer::line_count (rest) * staff_space / 2;
1381 /* Always move discretely by half spaces */
1382 shift = ceil (fabs (shift * 2.0)) / 2.0 * sign (shift);
1384 /* Inside staff, move by whole spaces*/
1385 if ((rest_extent[d] + staff_space * shift) * d
1387 || (rest_extent[-d] + staff_space * shift) * -d
1389 shift = ceil (fabs (shift)) * sign (shift);
1391 return scm_from_double (staff_space * shift);
1395 Beam::is_knee (Grob *me)
1397 SCM k = me->get_property ("knee");
1398 if (scm_is_bool (k))
1399 return ly_scm2bool (k);
1403 extract_grob_set (me, "stems", stems);
1404 for (vsize i = stems.size (); i--;)
1406 Direction dir = get_grob_direction (stems[i]);
1415 me->set_property ("knee", ly_bool2scm (knee));
1421 Beam::get_direction_beam_count (Grob *me, Direction d)
1423 extract_grob_set (me, "stems", stems);
1426 for (vsize i = stems.size (); i--;)
1429 Should we take invisible stems into account?
1431 if (get_grob_direction (stems[i]) == d)
1432 bc = max (bc, (Stem::beam_multiplicity (stems[i]).length () + 1));
1438 ADD_INTERFACE (Beam,
1442 "The @code{thickness} property is the weight of beams, "
1443 "measured in staffspace. The @code{direction} "
1444 "property is not user-serviceable. Use "
1445 "the @code{direction} property of @code{Stem} instead. "
1451 "beamed-stem-shorten "
1466 "neutral-direction "
1469 "quantized-positions "