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 /* ugh, this has a side-effect that we need to ensure that
300 Stem #'beaming is correct */
301 (void) me_grob->get_property ("quantized-positions");
303 Spanner *me = dynamic_cast<Spanner*> (me_grob);
305 extract_grob_set (me, "stems", stems);
306 Grob *commonx = common_refpoint_of_array (stems, me, X_AXIS);
308 commonx = me->get_bound (LEFT)->common_refpoint (commonx, X_AXIS);
309 commonx = me->get_bound (RIGHT)->common_refpoint (commonx, X_AXIS);
313 int gap_count = robust_scm2int (me->get_property ("gap-count"), 0);
314 Real gap_length = robust_scm2double (me->get_property ("gap"), 0.0);
316 Position_stem_segments_map stem_segments;
317 Real lt = me->layout ()->get_dimension (ly_symbol2scm ("line-thickness"));
321 for (vsize i = 0; i < stems.size (); i++)
323 Grob *stem = stems[i];
324 Real stem_width = robust_scm2double (stem->get_property ("thickness"), 1.0) * lt;
325 Real stem_x = stem->relative_coordinate (commonx, X_AXIS);
326 SCM beaming = stem->get_property ("beaming");
330 for (SCM s = index_get_cell (beaming, d);
331 scm_is_pair (s); s = scm_cdr (s))
333 if (!scm_is_integer (scm_car (s)))
336 int beam_rank = scm_to_int (scm_car (s));
337 ranks.add_point (beam_rank);
340 for (SCM s = index_get_cell (beaming, d);
341 scm_is_pair (s); s = scm_cdr (s))
343 if (!scm_is_integer (scm_car (s)))
346 int beam_rank = scm_to_int (scm_car (s));
347 Beam_stem_segment seg;
349 seg.stem_x_ = stem_x;
350 seg.rank_ = 2 * i + (d+1)/2;
351 seg.width_ = stem_width;
354 seg.max_connect_ = robust_scm2int (stem->get_property ("max-beam-connect"), 1000);
356 Direction stem_dir = get_grob_direction (stem);
359 = (stem_dir * beam_rank < (stem_dir * ranks[-stem_dir] + gap_count));
360 stem_segments[beam_rank].push_back (seg);
363 while (flip (&d) != LEFT);
366 Drul_array<Real> break_overshoot
367 = robust_scm2drul (me->get_property ("break-overshoot"),
368 Drul_array<Real> (-0.5, 0.0));
370 vector<Beam_segment> segments;
371 for (Position_stem_segments_map::const_iterator i (stem_segments.begin ());
372 i != stem_segments.end (); i++)
374 vector<Beam_stem_segment> segs = (*i).second;
375 vector_sort (segs, less<Beam_stem_segment> ());
377 Beam_segment current;
379 int vertical_count = (*i).first;
380 for (vsize j = 0; j < segs.size (); j++)
383 event_dir == LEFT: left edge of a beamsegment.
385 Direction event_dir = LEFT;
388 Drul_array<bool> on_bound (j == 0 && event_dir==LEFT,
389 j == segs.size() - 1 && event_dir==RIGHT);
390 Drul_array<bool> inside (j > 0, j < segs.size()-1);
391 bool event = on_bound[event_dir]
392 || abs (segs[j].rank_ - segs[j+event_dir].rank_) > 1
393 || (abs (vertical_count) >= segs[j].max_connect_
394 || abs (vertical_count) >= segs[j + event_dir].max_connect_);
399 current.vertical_count_ = vertical_count;
400 current.horizontal_[event_dir] = segs[j].stem_x_;
401 if (segs[j].dir_ == event_dir)
403 if (on_bound[event_dir]
404 && me->get_bound (event_dir)->break_status_dir ())
406 current.horizontal_[event_dir]
407 = (me->get_bound (event_dir)->extent (commonx, X_AXIS)[RIGHT]
408 + event_dir * break_overshoot[event_dir]);
412 Real notehead_width =
413 Stem::duration_log (segs[j].stem_) == 1
417 if (inside[event_dir])
418 notehead_width = min (notehead_width,
419 fabs (segs[j+ event_dir].stem_x_
420 - segs[j].stem_x_)/2);
422 current.horizontal_[event_dir] += event_dir * notehead_width;
427 current.horizontal_[event_dir] += event_dir * segs[j].width_/2;
429 current.horizontal_[event_dir] -= event_dir * gap_length;
432 if (event_dir == RIGHT)
434 segments.push_back (current);
435 current = Beam_segment();
438 while (flip (&event_dir) != LEFT);
446 MAKE_SCHEME_CALLBACK(Beam, print, 1);
448 Beam::print (SCM grob)
450 Spanner *me = unsmob_spanner (grob);
452 vector<Beam_segment> segments = get_beam_segments (me, &commonx);
455 if (visible_stem_count (me))
457 span[LEFT] = first_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
458 span[RIGHT] = last_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
462 extract_grob_set (me, "stems", stems);
463 span[LEFT] = stems[0]->relative_coordinate (commonx, X_AXIS);
464 span[RIGHT] = stems.back ()->relative_coordinate (commonx, X_AXIS);
467 Real blot = me->layout ()->get_dimension (ly_symbol2scm ("blot-diameter"));
469 SCM posns = me->get_property ("quantized-positions");
471 if (!is_number_pair (posns))
473 programming_error ("no beam positions?");
474 pos = Interval (0, 0);
477 pos = ly_scm2realdrul (posns);
479 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
481 Real dy = pos[RIGHT] - pos[LEFT];
482 Real slope = (dy && span.length ()) ? dy / span.length () : 0;
484 Real thick = get_thickness (me);
485 Real beam_dy = get_beam_translation (me);
487 Direction feather_dir = to_dir (me->get_property ("grow-direction"));
490 for (vsize i = 0; i < segments.size (); i ++)
492 Real local_slope = slope;
495 local_slope += feather_dir * segments[i].vertical_count_ * beam_dy / span.length ();
498 Stencil b = Lookup::beam (local_slope, segments[i].horizontal_.length (), thick, blot);
500 b.translate_axis (segments[i].horizontal_[LEFT], X_AXIS);
502 b.translate_axis (local_slope
503 * (segments[i].horizontal_[LEFT] - span.linear_combination (feather_dir))
504 + pos.linear_combination (feather_dir)
505 + beam_dy * segments[i].vertical_count_, Y_AXIS);
506 the_beam.add_stencil (b);
509 #if (DEBUG_BEAM_SCORING)
510 SCM quant_score = me->get_property ("quant-score");
511 SCM debug = me->layout ()->lookup_variable (ly_symbol2scm ("debug-beam-scoring"));
512 if (to_boolean (debug) && scm_is_string (quant_score))
514 extract_grob_set (me, "stems", stems);
517 This code prints the demerits for each beam. Perhaps this
518 should be switchable for those who want to twiddle with the
522 SCM properties = Font_interface::text_font_alist_chain (me);
524 Direction stem_dir = stems.size () ? to_dir (stems[0]->get_property ("direction")) : UP;
526 Stencil score = *unsmob_stencil (Text_interface::interpret_markup
527 (me->layout ()->self_scm (), properties, quant_score));
529 if (!score.is_empty ())
530 the_beam.add_at_edge (Y_AXIS, stem_dir, score, 1.0, 0);
534 the_beam.translate_axis (-me->relative_coordinate (commonx, X_AXIS), X_AXIS);
535 return the_beam.smobbed_copy ();
539 Beam::get_default_dir (Grob *me)
541 extract_grob_set (me, "stems", stems);
543 Drul_array<Real> extremes (0.0, 0.0);
544 for (iterof (s, stems); s != stems.end (); s++)
546 Interval positions = Stem::head_positions (*s);
550 if (sign (positions[d]) == d)
551 extremes[d] = d * max (d * positions[d], d * extremes[d]);
553 while (flip (&d) != DOWN);
556 Drul_array<int> total (0, 0);
557 Drul_array<int> count (0, 0);
559 bool force_dir = false;
560 for (vsize i = 0; i < stems.size (); i++)
563 Direction stem_dir = CENTER;
564 SCM stem_dir_scm = s->get_property_data ("direction");
565 if (is_direction (stem_dir_scm))
567 stem_dir = to_dir (stem_dir_scm);
571 stem_dir = to_dir (s->get_property ("default-direction"));
574 stem_dir = to_dir (s->get_property ("neutral-direction"));
579 total[stem_dir] += max (int (- stem_dir * Stem::head_positions (s) [-stem_dir]), 0);
586 if (abs (extremes[UP]) > -extremes[DOWN])
588 else if (extremes[UP] < -extremes[DOWN])
592 Direction dir = CENTER;
593 Direction d = CENTER;
594 if ((d = (Direction) sign (count[UP] - count[DOWN])))
598 && (d = (Direction) sign (total[UP] / count[UP] - total[DOWN]/count[DOWN])))
600 else if ((d = (Direction) sign (total[UP] - total[DOWN])))
603 dir = to_dir (me->get_property ("neutral-direction"));
608 /* Set all stems with non-forced direction to beam direction.
609 Urg: non-forced should become `without/with unforced' direction,
610 once stem gets cleaned-up. */
612 Beam::set_stem_directions (Grob *me, Direction d)
614 extract_grob_set (me, "stems", stems);
616 for (vsize i = 0; i < stems.size (); i++)
620 SCM forcedir = s->get_property_data ("direction");
621 if (!to_dir (forcedir))
622 set_grob_direction (s, d);
627 Only try horizontal beams for knees. No reliable detection of
628 anything else is possible here, since we don't know funky-beaming
629 settings, or X-distances (slopes!) People that want sloped
630 knee-beams, should set the directions manually.
635 this routine should take into account the stemlength scoring
636 of a possible knee/nonknee beam.
639 Beam::consider_auto_knees (Grob *me)
641 SCM scm = me->get_property ("auto-knee-gap");
642 if (!scm_is_number (scm))
649 extract_grob_set (me, "stems", stems);
651 Grob *common = common_refpoint_of_array (stems, me, Y_AXIS);
652 Real staff_space = Staff_symbol_referencer::staff_space (me);
654 vector<Interval> head_extents_array;
655 for (vsize i = 0; i < stems.size (); i++)
657 Grob *stem = stems[i];
658 if (Stem::is_invisible (stem))
661 Interval head_extents = Stem::head_positions (stem);
662 if (!head_extents.is_empty ())
664 head_extents[LEFT] += -1;
665 head_extents[RIGHT] += 1;
666 head_extents *= staff_space * 0.5;
669 We could subtract beam Y position, but this routine only
670 sets stem directions, a constant shift does not have an
673 head_extents += stem->relative_coordinate (common, Y_AXIS);
675 if (to_dir (stem->get_property_data ("direction")))
677 Direction stemdir = to_dir (stem->get_property ("direction"));
678 head_extents[-stemdir] = -stemdir * infinity_f;
681 head_extents_array.push_back (head_extents);
683 gaps.remove_interval (head_extents);
687 Real max_gap_len = 0.0;
689 for (vsize i = gaps.allowed_regions_.size () -1; i != VPOS ;i--)
691 Interval gap = gaps.allowed_regions_[i];
694 the outer gaps are not knees.
696 if (isinf (gap[LEFT]) || isinf (gap[RIGHT]))
699 if (gap.length () >= max_gap_len)
701 max_gap_len = gap.length ();
706 Real beam_translation = get_beam_translation (me);
707 Real beam_thickness = Beam::get_thickness (me);
708 int beam_count = Beam::get_beam_count (me);
709 Real height_of_beams = beam_thickness / 2
710 + (beam_count - 1) * beam_translation;
711 Real threshold = scm_to_double (scm) + height_of_beams;
713 if (max_gap_len > threshold)
716 for (vsize i = 0; i < stems.size (); i++)
718 Grob *stem = stems[i];
719 if (Stem::is_invisible (stem))
722 Interval head_extents = head_extents_array[j++];
724 Direction d = (head_extents.center () < max_gap.center ())
727 stem->set_property ("direction", scm_from_int (d));
729 head_extents.intersect (max_gap);
730 assert (head_extents.is_empty () || head_extents.length () < 1e-6);
735 /* Set stem's shorten property if unset.
738 take some y-position (chord/beam/nearest?) into account
739 scmify forced-fraction
741 This is done in beam because the shorten has to be uniform over the
748 set_minimum_dy (Grob *me, Real *dy)
753 If dy is smaller than the smallest quant, we
754 get absurd direction-sign penalties.
757 Real ss = Staff_symbol_referencer::staff_space (me);
758 Real thickness = Beam::get_thickness (me) / ss;
759 Real slt = Staff_symbol_referencer::line_thickness (me) / ss;
760 Real sit = (thickness - slt) / 2;
762 Real hang = 1.0 - (thickness - slt) / 2;
764 *dy = sign (*dy) * max (fabs (*dy),
765 min (min (sit, inter), hang));
771 MAKE_SCHEME_CALLBACK(Beam, calc_stem_shorten, 1)
773 Beam::calc_stem_shorten (SCM smob)
775 Grob *me = unsmob_grob (smob);
778 shortening looks silly for x staff beams
781 return scm_from_int (0);
783 Real forced_fraction = 1.0 * forced_stem_count (me)
784 / visible_stem_count (me);
786 int beam_count = get_beam_count (me);
788 SCM shorten_list = me->get_property ("beamed-stem-shorten");
789 if (shorten_list == SCM_EOL)
790 return scm_from_int (0);
792 Real staff_space = Staff_symbol_referencer::staff_space (me);
795 = robust_list_ref (beam_count -1, shorten_list);
796 Real shorten = scm_to_double (shorten_elt) * staff_space;
798 shorten *= forced_fraction;
802 return scm_from_double (shorten);
804 return scm_from_double (0.0);
810 Compute a first approximation to the beam slope.
812 MAKE_SCHEME_CALLBACK (Beam, calc_least_squares_positions, 2);
814 Beam::calc_least_squares_positions (SCM smob, SCM posns)
818 Grob *me = unsmob_grob (smob);
820 int count = visible_stem_count (me);
823 return ly_interval2scm (pos);
825 vector<Real> x_posns;
826 extract_grob_set (me, "stems", stems);
827 Grob *commonx = common_refpoint_of_array (stems, me, X_AXIS);
828 Grob *commony = common_refpoint_of_array (stems, me, Y_AXIS);
830 Real my_y = me->relative_coordinate (commony, Y_AXIS);
832 Grob *fvs = first_visible_stem (me);
833 Grob *lvs = last_visible_stem (me);
835 Interval ideal (Stem::get_stem_info (fvs).ideal_y_
836 + fvs->relative_coordinate (commony, Y_AXIS) - my_y,
837 Stem::get_stem_info (lvs).ideal_y_
838 + lvs->relative_coordinate (commony, Y_AXIS) - my_y);
840 Real x0 = first_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
841 for (vsize i = 0; i < stems.size (); i++)
845 Real x = s->relative_coordinate (commonx, X_AXIS) - x0;
846 x_posns.push_back (x);
848 Real dx = last_visible_stem (me)->relative_coordinate (commonx, X_AXIS) - x0;
856 Interval chord (Stem::chord_start_y (first_visible_stem (me)),
857 Stem::chord_start_y (last_visible_stem (me)));
859 /* Simple beams (2 stems) on middle line should be allowed to be
862 However, if both stems reach middle line,
863 ideal[LEFT] == ideal[RIGHT] and ideal.delta () == 0.
865 For that case, we apply artificial slope */
866 if (!ideal[LEFT] && chord.delta () && count == 2)
869 Direction d = (Direction) (sign (chord.delta ()) * UP);
870 pos[d] = get_thickness (me) / 2;
877 For broken beams this doesn't work well. In this case, the
878 slope esp. of the first part of a broken beam should predict
879 where the second part goes.
881 ldy = pos[RIGHT] - pos[LEFT];
885 vector<Offset> ideals;
886 for (vsize i = 0; i < stems.size (); i++)
889 if (Stem::is_invisible (s))
891 ideals.push_back (Offset (x_posns[i],
892 Stem::get_stem_info (s).ideal_y_
893 + s->relative_coordinate (commony, Y_AXIS)
897 minimise_least_squares (&slope, &y, ideals);
901 set_minimum_dy (me, &dy);
904 pos = Interval (y, (y + dy));
908 "position" is relative to the staff.
910 scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
912 me->set_property ("least-squares-dy", scm_from_double (ldy));
913 return ly_interval2scm (pos);
917 We can't combine with previous function, since check concave and
918 slope damping comes first.
920 TODO: we should use the concaveness to control the amount of damping
923 MAKE_SCHEME_CALLBACK (Beam, shift_region_to_valid, 2);
925 Beam::shift_region_to_valid (SCM grob, SCM posns)
927 Grob *me = unsmob_grob (grob);
931 vector<Real> x_posns;
932 extract_grob_set (me, "stems", stems);
933 Grob *commonx = common_refpoint_of_array (stems, me, X_AXIS);
934 Grob *commony = common_refpoint_of_array (stems, me, Y_AXIS);
936 Grob *fvs = first_visible_stem (me);
941 Real x0 = fvs->relative_coordinate (commonx, X_AXIS);
942 for (vsize i = 0; i < stems.size (); i++)
946 Real x = s->relative_coordinate (commonx, X_AXIS) - x0;
947 x_posns.push_back (x);
950 Grob *lvs = last_visible_stem (me);
954 Real dx = lvs->relative_coordinate (commonx, X_AXIS) - x0;
956 Drul_array<Real> pos = ly_scm2interval (posns);
959 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
961 Real dy = pos[RIGHT] - pos[LEFT];
963 Real slope = dx ? (dy / dx) : 0.0;
966 Shift the positions so that we have a chance of finding good
967 quants (i.e. no short stem failures.)
969 Interval feasible_left_point;
970 feasible_left_point.set_full ();
971 for (vsize i = 0; i < stems.size (); i++)
974 if (Stem::is_invisible (s))
977 Direction d = get_grob_direction (s);
980 = Stem::get_stem_info (s).shortest_y_
981 - slope * x_posns [i];
984 left_y is now relative to the stem S. We want relative to
985 ourselves, so translate:
988 += + s->relative_coordinate (commony, Y_AXIS)
989 - me->relative_coordinate (commony, Y_AXIS);
995 feasible_left_point.intersect (flp);
998 if (feasible_left_point.is_empty ())
999 warning (_ ("no viable initial configuration found: may not find good beam slope"));
1000 else if (!feasible_left_point.contains (y))
1002 const int REGION_SIZE = 2; // UGH UGH
1003 if (isinf (feasible_left_point[DOWN]))
1004 y = feasible_left_point[UP] - REGION_SIZE;
1005 else if (isinf (feasible_left_point[UP]))
1006 y = feasible_left_point[DOWN]+ REGION_SIZE;
1008 y = feasible_left_point.center ();
1011 pos = Drul_array<Real> (y, (y + dy));
1012 scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
1014 return ly_interval2scm (pos);
1017 /* This neat trick is by Werner Lemberg,
1018 damped = tanh (slope)
1019 corresponds with some tables in [Wanske] CHECKME */
1020 MAKE_SCHEME_CALLBACK (Beam, slope_damping, 2);
1022 Beam::slope_damping (SCM smob, SCM posns)
1024 Grob *me = unsmob_grob (smob);
1025 Drul_array<Real> pos = ly_scm2interval (posns);
1027 if (visible_stem_count (me) <= 1)
1031 SCM s = me->get_property ("damping");
1032 Real damping = scm_to_double (s);
1033 Real concaveness = robust_scm2double (me->get_property ("concaveness"), 0.0);
1034 if (concaveness >= 10000)
1036 pos[LEFT] = pos[RIGHT];
1037 me->set_property ("least-squares-dy", scm_from_double (0));
1043 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
1045 Real dy = pos[RIGHT] - pos[LEFT];
1047 Grob *fvs = first_visible_stem (me);
1048 Grob *lvs = last_visible_stem (me);
1050 Grob *commonx = fvs->common_refpoint (lvs, X_AXIS);
1052 Real dx = last_visible_stem (me)->relative_coordinate (commonx, X_AXIS)
1053 - first_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
1055 Real slope = dy && dx ? dy / dx : 0;
1057 slope = 0.6 * tanh (slope) / (damping + concaveness);
1059 Real damped_dy = slope * dx;
1061 set_minimum_dy (me, &damped_dy);
1063 pos[LEFT] += (dy - damped_dy) / 2;
1064 pos[RIGHT] -= (dy - damped_dy) / 2;
1066 scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
1069 return ly_interval2scm (pos);
1073 Report slice containing the numbers that are both in (car BEAMING)
1077 where_are_the_whole_beams (SCM beaming)
1081 for (SCM s = scm_car (beaming); scm_is_pair (s); s = scm_cdr (s))
1083 if (scm_c_memq (scm_car (s), scm_cdr (beaming)) != SCM_BOOL_F)
1085 l.add_point (scm_to_int (scm_car (s)));
1091 /* Return the Y position of the stem-end, given the Y-left, Y-right
1092 in POS for stem S. This Y position is relative to S. */
1094 Beam::calc_stem_y (Grob *me, Grob *stem, Grob **common,
1096 Drul_array<Real> pos, bool french)
1098 Real beam_translation = get_beam_translation (me);
1100 Real r = stem->relative_coordinate (common[X_AXIS], X_AXIS) - xl;
1101 Real dy = pos[RIGHT] - pos[LEFT];
1103 Real stem_y_beam0 = (dy && dx
1108 Direction my_dir = get_grob_direction (stem);
1109 SCM beaming = stem->get_property ("beaming");
1111 Real stem_y = stem_y_beam0;
1114 Slice bm = where_are_the_whole_beams (beaming);
1115 if (!bm.is_empty ())
1116 stem_y += beam_translation * bm[-my_dir];
1120 Slice bm = Stem::beam_multiplicity (stem);
1121 if (!bm.is_empty ())
1122 stem_y += bm[my_dir] * beam_translation;
1125 Real id = me->relative_coordinate (common[Y_AXIS], Y_AXIS)
1126 - stem->relative_coordinate (common[Y_AXIS], Y_AXIS);
1132 Hmm. At this time, beam position and slope are determined. Maybe,
1133 stem directions and length should set to relative to the chord's
1134 position of the beam. */
1135 MAKE_SCHEME_CALLBACK(Beam, set_stem_lengths, 1);
1137 Beam::set_stem_lengths (SCM smob)
1139 Grob *me = unsmob_grob (smob);
1141 /* trigger callbacks. */
1142 (void) me->get_property ("direction");
1143 (void) me->get_property ("beaming");
1145 SCM posns = me->get_property ("positions");
1147 extract_grob_set (me, "stems", stems);
1152 for (int a = 2; a--;)
1153 common[a] = common_refpoint_of_array (stems, me, Axis (a));
1155 Drul_array<Real> pos = ly_scm2realdrul (posns);
1156 Real staff_space = Staff_symbol_referencer::staff_space (me);
1157 scale_drul (&pos, staff_space);
1161 if (robust_scm2int (me->get_property ("gap-count"), 0))
1164 thick = get_thickness (me);
1167 Grob *fvs = first_visible_stem (me);
1168 Grob *lvs = last_visible_stem (me);
1170 Real xl = fvs ? fvs->relative_coordinate (common[X_AXIS], X_AXIS) : 0.0;
1171 Real xr = lvs ? lvs->relative_coordinate (common[X_AXIS], X_AXIS) : 0.0;
1173 for (vsize i = 0; i < stems.size (); i++)
1177 bool french = to_boolean (s->get_property ("french-beaming"));
1178 Real stem_y = calc_stem_y (me, s, common,
1180 pos, french && s != lvs && s!= fvs);
1183 Make the stems go up to the end of the beam. This doesn't matter
1184 for normal beams, but for tremolo beams it looks silly otherwise.
1187 && !Stem::is_invisible (s))
1188 stem_y += thick * 0.5 * get_grob_direction (s);
1191 Do set_stemend for invisible stems too, so tuplet brackets
1192 have a reference point for sloping
1194 Stem::set_stemend (s, 2 * stem_y / staff_space);
1201 Beam::set_beaming (Grob *me, Beaming_pattern const *beaming)
1203 extract_grob_set (me, "stems", stems);
1206 for (vsize i = 0; i < stems.size (); i++)
1209 Don't overwrite user settings.
1213 Grob *stem = stems[i];
1214 SCM beaming_prop = stem->get_property ("beaming");
1215 if (beaming_prop == SCM_EOL
1216 || index_get_cell (beaming_prop, d) == SCM_EOL)
1218 int count = beaming->beamlet_count (i, d);
1220 && i < stems.size () -1
1221 && Stem::is_invisible (stem))
1222 count = min (count, beaming->beamlet_count (i,-d));
1224 if ( ((i == 0 && d == LEFT)
1225 || (i == stems.size ()-1 && d == RIGHT))
1226 && stems.size () > 1
1227 && to_boolean (me->get_property ("clip-edges")))
1230 Stem::set_beaming (stem, count, d);
1233 while (flip (&d) != LEFT);
1238 Beam::forced_stem_count (Grob *me)
1240 extract_grob_set (me, "stems", stems);
1243 for (vsize i = 0; i < stems.size (); i++)
1247 if (Stem::is_invisible (s))
1250 /* I can imagine counting those boundaries as a half forced stem,
1251 but let's count them full for now. */
1252 Direction defdir = to_dir (s->get_property ("default-direction"));
1254 if (abs (Stem::chord_start_y (s)) > 0.1
1256 && get_grob_direction (s) != defdir)
1263 Beam::visible_stem_count (Grob *me)
1265 extract_grob_set (me, "stems", stems);
1267 for (vsize i = stems.size (); i--;)
1269 if (!Stem::is_invisible (stems[i]))
1276 Beam::first_visible_stem (Grob *me)
1278 extract_grob_set (me, "stems", stems);
1280 for (vsize i = 0; i < stems.size (); i++)
1282 if (!Stem::is_invisible (stems[i]))
1289 Beam::last_visible_stem (Grob *me)
1291 extract_grob_set (me, "stems", stems);
1293 for (vsize i = stems.size (); i--;)
1295 if (!Stem::is_invisible (stems[i]))
1304 handle rest under beam (do_post: beams are calculated now)
1305 what about combination of collisions and rest under beam.
1309 rest -> stem -> beam -> interpolate_y_position ()
1311 MAKE_SCHEME_CALLBACK_WITH_OPTARGS (Beam, rest_collision_callback, 2, 1);
1313 Beam::rest_collision_callback (SCM smob, SCM prev_offset)
1315 Grob *rest = unsmob_grob (smob);
1316 if (scm_is_number (rest->get_property ("staff-position")))
1317 return scm_from_int (0);
1319 Real offset = robust_scm2double (prev_offset, 0.0);
1321 Grob *st = unsmob_grob (rest->get_object ("stem"));
1324 return scm_from_double (0.0);
1325 Grob *beam = unsmob_grob (stem->get_object ("beam"));
1327 || !Beam::has_interface (beam)
1328 || !Beam::visible_stem_count (beam))
1329 return scm_from_double (0.0);
1331 Drul_array<Real> pos (0, 0);
1332 SCM s = beam->get_property ("positions");
1333 if (scm_is_pair (s) && scm_is_number (scm_car (s)))
1334 pos = ly_scm2interval (s);
1336 programming_error ("positions property should always be pair of numbers.");
1338 Real staff_space = Staff_symbol_referencer::staff_space (rest);
1340 scale_drul (&pos, staff_space);
1342 Real dy = pos[RIGHT] - pos[LEFT];
1344 Drul_array<Grob*> visible_stems (first_visible_stem (beam),
1345 last_visible_stem (beam));
1346 extract_grob_set (beam, "stems", stems);
1348 Grob *common = common_refpoint_of_array (stems, beam, X_AXIS);
1350 Real x0 = visible_stems[LEFT]->relative_coordinate (common, X_AXIS);
1351 Real dx = visible_stems[RIGHT]->relative_coordinate (common, X_AXIS) - x0;
1352 Real slope = dy && dx ? dy / dx : 0;
1354 Direction d = get_grob_direction (stem);
1355 Real stem_y = pos[LEFT]
1356 + (stem->relative_coordinate (common, X_AXIS) - x0) * slope;
1358 Real beam_translation = get_beam_translation (beam);
1359 Real beam_thickness = Beam::get_thickness (beam);
1362 TODO: this is not strictly correct for 16th knee beams.
1365 = Stem::beam_multiplicity (stem).length () + 1;
1367 Real height_of_my_beams = beam_thickness / 2
1368 + (beam_count - 1) * beam_translation;
1369 Real beam_y = stem_y - d * height_of_my_beams;
1371 Grob *common_y = rest->common_refpoint (beam, Y_AXIS);
1372 Interval rest_extent = rest->extent (common_y, Y_AXIS);
1373 rest_extent.translate (offset);
1375 Real rest_dim = rest_extent[d];
1376 Real minimum_distance
1377 = staff_space * (robust_scm2double (stem->get_property ("stemlet-length"), 0.0)
1378 + robust_scm2double (rest->get_property ("minimum-distance"), 0.0));
1380 Real shift = d * min (((beam_y - d * minimum_distance) - rest_dim) * d, 0.0);
1382 shift /= staff_space;
1383 Real rad = Staff_symbol_referencer::line_count (rest) * staff_space / 2;
1385 /* Always move discretely by half spaces */
1386 shift = ceil (fabs (shift * 2.0)) / 2.0 * sign (shift);
1388 /* Inside staff, move by whole spaces*/
1389 if ((rest_extent[d] + staff_space * shift) * d
1391 || (rest_extent[-d] + staff_space * shift) * -d
1393 shift = ceil (fabs (shift)) * sign (shift);
1395 return scm_from_double (staff_space * shift);
1399 Beam::is_knee (Grob *me)
1401 SCM k = me->get_property ("knee");
1402 if (scm_is_bool (k))
1403 return ly_scm2bool (k);
1407 extract_grob_set (me, "stems", stems);
1408 for (vsize i = stems.size (); i--;)
1410 Direction dir = get_grob_direction (stems[i]);
1419 me->set_property ("knee", ly_bool2scm (knee));
1425 Beam::get_direction_beam_count (Grob *me, Direction d)
1427 extract_grob_set (me, "stems", stems);
1430 for (vsize i = stems.size (); i--;)
1433 Should we take invisible stems into account?
1435 if (get_grob_direction (stems[i]) == d)
1436 bc = max (bc, (Stem::beam_multiplicity (stems[i]).length () + 1));
1442 ADD_INTERFACE (Beam,
1445 "The @code{thickness} property is the weight of beams, "
1446 "measured in staffspace. The @code{direction} "
1447 "property is not user-serviceable. Use "
1448 "the @code{direction} property of @code{Stem} instead. "
1454 "beamed-stem-shorten "
1469 "neutral-direction "
1472 "quantized-positions "