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 bool on_bound = (event_dir == LEFT) ? j == 0 :
385 j == segs.size() - 1;
387 bool inside_stem = (event_dir == LEFT)
388 ? segs[j].stem_index_ > 0
389 : segs[j].stem_index_ < stems.size () - 1;
391 bool event = on_bound
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)
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
420 Grob *neighbor_stem = stems[segs[j].stem_index_ + event_dir];
421 Real neighbor_stem_x = neighbor_stem->relative_coordinate (commonx, X_AXIS);
423 notehead_width = min (notehead_width,
424 fabs (neighbor_stem_x - segs[j].stem_x_)/2);
426 current.horizontal_[event_dir] += event_dir * notehead_width;
431 current.horizontal_[event_dir] += event_dir * segs[j].width_/2;
433 current.horizontal_[event_dir] -= event_dir * gap_length;
436 if (event_dir == RIGHT)
438 segments.push_back (current);
439 current = Beam_segment();
442 while (flip (&event_dir) != LEFT);
450 MAKE_SCHEME_CALLBACK(Beam, print, 1);
452 Beam::print (SCM grob)
454 Spanner *me = unsmob_spanner (grob);
456 vector<Beam_segment> segments = get_beam_segments (me, &commonx);
459 if (visible_stem_count (me))
461 span[LEFT] = first_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
462 span[RIGHT] = last_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
466 extract_grob_set (me, "stems", stems);
467 span[LEFT] = stems[0]->relative_coordinate (commonx, X_AXIS);
468 span[RIGHT] = stems.back ()->relative_coordinate (commonx, X_AXIS);
471 Real blot = me->layout ()->get_dimension (ly_symbol2scm ("blot-diameter"));
473 SCM posns = me->get_property ("quantized-positions");
475 if (!is_number_pair (posns))
477 programming_error ("no beam positions?");
478 pos = Interval (0, 0);
481 pos = ly_scm2realdrul (posns);
483 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
485 Real dy = pos[RIGHT] - pos[LEFT];
486 Real slope = (dy && span.length ()) ? dy / span.length () : 0;
488 Real thick = get_thickness (me);
489 Real beam_dy = get_beam_translation (me);
491 Direction feather_dir = to_dir (me->get_property ("grow-direction"));
494 for (vsize i = 0; i < segments.size (); i ++)
496 Real local_slope = slope;
499 local_slope += feather_dir * segments[i].vertical_count_ * beam_dy / span.length ();
502 Stencil b = Lookup::beam (local_slope, segments[i].horizontal_.length (), thick, blot);
504 b.translate_axis (segments[i].horizontal_[LEFT], X_AXIS);
506 b.translate_axis (local_slope
507 * (segments[i].horizontal_[LEFT] - span.linear_combination (feather_dir))
508 + pos.linear_combination (feather_dir)
509 + beam_dy * segments[i].vertical_count_, Y_AXIS);
510 the_beam.add_stencil (b);
513 #if (DEBUG_BEAM_SCORING)
514 SCM quant_score = me->get_property ("quant-score");
515 SCM debug = me->layout ()->lookup_variable (ly_symbol2scm ("debug-beam-scoring"));
516 if (to_boolean (debug) && scm_is_string (quant_score))
518 extract_grob_set (me, "stems", stems);
521 This code prints the demerits for each beam. Perhaps this
522 should be switchable for those who want to twiddle with the
526 SCM properties = Font_interface::text_font_alist_chain (me);
528 Direction stem_dir = stems.size () ? to_dir (stems[0]->get_property ("direction")) : UP;
530 Stencil score = *unsmob_stencil (Text_interface::interpret_markup
531 (me->layout ()->self_scm (), properties, quant_score));
533 if (!score.is_empty ())
534 the_beam.add_at_edge (Y_AXIS, stem_dir, score, 1.0, 0);
538 the_beam.translate_axis (-me->relative_coordinate (commonx, X_AXIS), X_AXIS);
539 return the_beam.smobbed_copy ();
543 Beam::get_default_dir (Grob *me)
545 extract_grob_set (me, "stems", stems);
547 Drul_array<Real> extremes (0.0, 0.0);
548 for (iterof (s, stems); s != stems.end (); s++)
550 Interval positions = Stem::head_positions (*s);
554 if (sign (positions[d]) == d)
555 extremes[d] = d * max (d * positions[d], d * extremes[d]);
557 while (flip (&d) != DOWN);
560 Drul_array<int> total (0, 0);
561 Drul_array<int> count (0, 0);
563 bool force_dir = false;
564 for (vsize i = 0; i < stems.size (); i++)
567 Direction stem_dir = CENTER;
568 SCM stem_dir_scm = s->get_property_data ("direction");
569 if (is_direction (stem_dir_scm))
571 stem_dir = to_dir (stem_dir_scm);
575 stem_dir = to_dir (s->get_property ("default-direction"));
578 stem_dir = to_dir (s->get_property ("neutral-direction"));
583 total[stem_dir] += max (int (- stem_dir * Stem::head_positions (s) [-stem_dir]), 0);
590 if (abs (extremes[UP]) > -extremes[DOWN])
592 else if (extremes[UP] < -extremes[DOWN])
596 Direction dir = CENTER;
597 Direction d = CENTER;
598 if ((d = (Direction) sign (count[UP] - count[DOWN])))
602 && (d = (Direction) sign (total[UP] / count[UP] - total[DOWN]/count[DOWN])))
604 else if ((d = (Direction) sign (total[UP] - total[DOWN])))
607 dir = to_dir (me->get_property ("neutral-direction"));
612 /* Set all stems with non-forced direction to beam direction.
613 Urg: non-forced should become `without/with unforced' direction,
614 once stem gets cleaned-up. */
616 Beam::set_stem_directions (Grob *me, Direction d)
618 extract_grob_set (me, "stems", stems);
620 for (vsize i = 0; i < stems.size (); i++)
624 SCM forcedir = s->get_property_data ("direction");
625 if (!to_dir (forcedir))
626 set_grob_direction (s, d);
631 Only try horizontal beams for knees. No reliable detection of
632 anything else is possible here, since we don't know funky-beaming
633 settings, or X-distances (slopes!) People that want sloped
634 knee-beams, should set the directions manually.
639 this routine should take into account the stemlength scoring
640 of a possible knee/nonknee beam.
643 Beam::consider_auto_knees (Grob *me)
645 SCM scm = me->get_property ("auto-knee-gap");
646 if (!scm_is_number (scm))
653 extract_grob_set (me, "stems", stems);
655 Grob *common = common_refpoint_of_array (stems, me, Y_AXIS);
656 Real staff_space = Staff_symbol_referencer::staff_space (me);
658 vector<Interval> head_extents_array;
659 for (vsize i = 0; i < stems.size (); i++)
661 Grob *stem = stems[i];
662 if (Stem::is_invisible (stem))
665 Interval head_extents = Stem::head_positions (stem);
666 if (!head_extents.is_empty ())
668 head_extents[LEFT] += -1;
669 head_extents[RIGHT] += 1;
670 head_extents *= staff_space * 0.5;
673 We could subtract beam Y position, but this routine only
674 sets stem directions, a constant shift does not have an
677 head_extents += stem->relative_coordinate (common, Y_AXIS);
679 if (to_dir (stem->get_property_data ("direction")))
681 Direction stemdir = to_dir (stem->get_property ("direction"));
682 head_extents[-stemdir] = -stemdir * infinity_f;
685 head_extents_array.push_back (head_extents);
687 gaps.remove_interval (head_extents);
691 Real max_gap_len = 0.0;
693 for (vsize i = gaps.allowed_regions_.size () -1; i != VPOS ;i--)
695 Interval gap = gaps.allowed_regions_[i];
698 the outer gaps are not knees.
700 if (isinf (gap[LEFT]) || isinf (gap[RIGHT]))
703 if (gap.length () >= max_gap_len)
705 max_gap_len = gap.length ();
710 Real beam_translation = get_beam_translation (me);
711 Real beam_thickness = Beam::get_thickness (me);
712 int beam_count = Beam::get_beam_count (me);
713 Real height_of_beams = beam_thickness / 2
714 + (beam_count - 1) * beam_translation;
715 Real threshold = scm_to_double (scm) + height_of_beams;
717 if (max_gap_len > threshold)
720 for (vsize i = 0; i < stems.size (); i++)
722 Grob *stem = stems[i];
723 if (Stem::is_invisible (stem))
726 Interval head_extents = head_extents_array[j++];
728 Direction d = (head_extents.center () < max_gap.center ())
731 stem->set_property ("direction", scm_from_int (d));
733 head_extents.intersect (max_gap);
734 assert (head_extents.is_empty () || head_extents.length () < 1e-6);
739 /* Set stem's shorten property if unset.
742 take some y-position (chord/beam/nearest?) into account
743 scmify forced-fraction
745 This is done in beam because the shorten has to be uniform over the
752 set_minimum_dy (Grob *me, Real *dy)
757 If dy is smaller than the smallest quant, we
758 get absurd direction-sign penalties.
761 Real ss = Staff_symbol_referencer::staff_space (me);
762 Real thickness = Beam::get_thickness (me) / ss;
763 Real slt = Staff_symbol_referencer::line_thickness (me) / ss;
764 Real sit = (thickness - slt) / 2;
766 Real hang = 1.0 - (thickness - slt) / 2;
768 *dy = sign (*dy) * max (fabs (*dy),
769 min (min (sit, inter), hang));
775 MAKE_SCHEME_CALLBACK(Beam, calc_stem_shorten, 1)
777 Beam::calc_stem_shorten (SCM smob)
779 Grob *me = unsmob_grob (smob);
782 shortening looks silly for x staff beams
785 return scm_from_int (0);
787 Real forced_fraction = 1.0 * forced_stem_count (me)
788 / visible_stem_count (me);
790 int beam_count = get_beam_count (me);
792 SCM shorten_list = me->get_property ("beamed-stem-shorten");
793 if (shorten_list == SCM_EOL)
794 return scm_from_int (0);
796 Real staff_space = Staff_symbol_referencer::staff_space (me);
799 = robust_list_ref (beam_count -1, shorten_list);
800 Real shorten = scm_to_double (shorten_elt) * staff_space;
802 shorten *= forced_fraction;
806 return scm_from_double (shorten);
808 return scm_from_double (0.0);
814 Compute a first approximation to the beam slope.
816 MAKE_SCHEME_CALLBACK (Beam, calc_least_squares_positions, 2);
818 Beam::calc_least_squares_positions (SCM smob, SCM posns)
822 Grob *me = unsmob_grob (smob);
824 int count = visible_stem_count (me);
827 return ly_interval2scm (pos);
829 vector<Real> x_posns;
830 extract_grob_set (me, "stems", stems);
831 Grob *commonx = common_refpoint_of_array (stems, me, X_AXIS);
832 Grob *commony = common_refpoint_of_array (stems, me, Y_AXIS);
834 Real my_y = me->relative_coordinate (commony, Y_AXIS);
836 Grob *fvs = first_visible_stem (me);
837 Grob *lvs = last_visible_stem (me);
839 Interval ideal (Stem::get_stem_info (fvs).ideal_y_
840 + fvs->relative_coordinate (commony, Y_AXIS) - my_y,
841 Stem::get_stem_info (lvs).ideal_y_
842 + lvs->relative_coordinate (commony, Y_AXIS) - my_y);
844 Real x0 = first_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
845 for (vsize i = 0; i < stems.size (); i++)
849 Real x = s->relative_coordinate (commonx, X_AXIS) - x0;
850 x_posns.push_back (x);
852 Real dx = last_visible_stem (me)->relative_coordinate (commonx, X_AXIS) - x0;
860 Interval chord (Stem::chord_start_y (first_visible_stem (me)),
861 Stem::chord_start_y (last_visible_stem (me)));
863 /* Simple beams (2 stems) on middle line should be allowed to be
866 However, if both stems reach middle line,
867 ideal[LEFT] == ideal[RIGHT] and ideal.delta () == 0.
869 For that case, we apply artificial slope */
870 if (!ideal[LEFT] && chord.delta () && count == 2)
873 Direction d = (Direction) (sign (chord.delta ()) * UP);
874 pos[d] = get_thickness (me) / 2;
881 For broken beams this doesn't work well. In this case, the
882 slope esp. of the first part of a broken beam should predict
883 where the second part goes.
885 ldy = pos[RIGHT] - pos[LEFT];
889 vector<Offset> ideals;
890 for (vsize i = 0; i < stems.size (); i++)
893 if (Stem::is_invisible (s))
895 ideals.push_back (Offset (x_posns[i],
896 Stem::get_stem_info (s).ideal_y_
897 + s->relative_coordinate (commony, Y_AXIS)
901 minimise_least_squares (&slope, &y, ideals);
905 set_minimum_dy (me, &dy);
908 pos = Interval (y, (y + dy));
912 "position" is relative to the staff.
914 scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
916 me->set_property ("least-squares-dy", scm_from_double (ldy));
917 return ly_interval2scm (pos);
921 We can't combine with previous function, since check concave and
922 slope damping comes first.
924 TODO: we should use the concaveness to control the amount of damping
927 MAKE_SCHEME_CALLBACK (Beam, shift_region_to_valid, 2);
929 Beam::shift_region_to_valid (SCM grob, SCM posns)
931 Grob *me = unsmob_grob (grob);
935 vector<Real> x_posns;
936 extract_grob_set (me, "stems", stems);
937 Grob *commonx = common_refpoint_of_array (stems, me, X_AXIS);
938 Grob *commony = common_refpoint_of_array (stems, me, Y_AXIS);
940 Grob *fvs = first_visible_stem (me);
945 Real x0 = fvs->relative_coordinate (commonx, X_AXIS);
946 for (vsize i = 0; i < stems.size (); i++)
950 Real x = s->relative_coordinate (commonx, X_AXIS) - x0;
951 x_posns.push_back (x);
954 Grob *lvs = last_visible_stem (me);
958 Real dx = lvs->relative_coordinate (commonx, X_AXIS) - x0;
960 Drul_array<Real> pos = ly_scm2interval (posns);
963 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
965 Real dy = pos[RIGHT] - pos[LEFT];
967 Real slope = dx ? (dy / dx) : 0.0;
970 Shift the positions so that we have a chance of finding good
971 quants (i.e. no short stem failures.)
973 Interval feasible_left_point;
974 feasible_left_point.set_full ();
975 for (vsize i = 0; i < stems.size (); i++)
978 if (Stem::is_invisible (s))
981 Direction d = get_grob_direction (s);
984 = Stem::get_stem_info (s).shortest_y_
985 - slope * x_posns [i];
988 left_y is now relative to the stem S. We want relative to
989 ourselves, so translate:
992 += + s->relative_coordinate (commony, Y_AXIS)
993 - me->relative_coordinate (commony, Y_AXIS);
999 feasible_left_point.intersect (flp);
1002 if (feasible_left_point.is_empty ())
1003 warning (_ ("no viable initial configuration found: may not find good beam slope"));
1004 else if (!feasible_left_point.contains (y))
1006 const int REGION_SIZE = 2; // UGH UGH
1007 if (isinf (feasible_left_point[DOWN]))
1008 y = feasible_left_point[UP] - REGION_SIZE;
1009 else if (isinf (feasible_left_point[UP]))
1010 y = feasible_left_point[DOWN]+ REGION_SIZE;
1012 y = feasible_left_point.center ();
1015 pos = Drul_array<Real> (y, (y + dy));
1016 scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
1018 return ly_interval2scm (pos);
1021 /* This neat trick is by Werner Lemberg,
1022 damped = tanh (slope)
1023 corresponds with some tables in [Wanske] CHECKME */
1024 MAKE_SCHEME_CALLBACK (Beam, slope_damping, 2);
1026 Beam::slope_damping (SCM smob, SCM posns)
1028 Grob *me = unsmob_grob (smob);
1029 Drul_array<Real> pos = ly_scm2interval (posns);
1031 if (visible_stem_count (me) <= 1)
1035 SCM s = me->get_property ("damping");
1036 Real damping = scm_to_double (s);
1037 Real concaveness = robust_scm2double (me->get_property ("concaveness"), 0.0);
1038 if (concaveness >= 10000)
1040 pos[LEFT] = pos[RIGHT];
1041 me->set_property ("least-squares-dy", scm_from_double (0));
1047 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
1049 Real dy = pos[RIGHT] - pos[LEFT];
1051 Grob *fvs = first_visible_stem (me);
1052 Grob *lvs = last_visible_stem (me);
1054 Grob *commonx = fvs->common_refpoint (lvs, X_AXIS);
1056 Real dx = last_visible_stem (me)->relative_coordinate (commonx, X_AXIS)
1057 - first_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
1059 Real slope = dy && dx ? dy / dx : 0;
1061 slope = 0.6 * tanh (slope) / (damping + concaveness);
1063 Real damped_dy = slope * dx;
1065 set_minimum_dy (me, &damped_dy);
1067 pos[LEFT] += (dy - damped_dy) / 2;
1068 pos[RIGHT] -= (dy - damped_dy) / 2;
1070 scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
1073 return ly_interval2scm (pos);
1077 Report slice containing the numbers that are both in (car BEAMING)
1081 where_are_the_whole_beams (SCM beaming)
1085 for (SCM s = scm_car (beaming); scm_is_pair (s); s = scm_cdr (s))
1087 if (scm_c_memq (scm_car (s), scm_cdr (beaming)) != SCM_BOOL_F)
1089 l.add_point (scm_to_int (scm_car (s)));
1095 /* Return the Y position of the stem-end, given the Y-left, Y-right
1096 in POS for stem S. This Y position is relative to S. */
1098 Beam::calc_stem_y (Grob *me, Grob *stem, Grob **common,
1100 Drul_array<Real> pos, bool french)
1102 Real beam_translation = get_beam_translation (me);
1104 Real r = stem->relative_coordinate (common[X_AXIS], X_AXIS) - xl;
1105 Real dy = pos[RIGHT] - pos[LEFT];
1107 Real stem_y_beam0 = (dy && dx
1112 Direction my_dir = get_grob_direction (stem);
1113 SCM beaming = stem->get_property ("beaming");
1115 Real stem_y = stem_y_beam0;
1118 Slice bm = where_are_the_whole_beams (beaming);
1119 if (!bm.is_empty ())
1120 stem_y += beam_translation * bm[-my_dir];
1124 Slice bm = Stem::beam_multiplicity (stem);
1125 if (!bm.is_empty ())
1126 stem_y += bm[my_dir] * beam_translation;
1129 Real id = me->relative_coordinate (common[Y_AXIS], Y_AXIS)
1130 - stem->relative_coordinate (common[Y_AXIS], Y_AXIS);
1136 Hmm. At this time, beam position and slope are determined. Maybe,
1137 stem directions and length should set to relative to the chord's
1138 position of the beam. */
1139 MAKE_SCHEME_CALLBACK(Beam, set_stem_lengths, 1);
1141 Beam::set_stem_lengths (SCM smob)
1143 Grob *me = unsmob_grob (smob);
1145 /* trigger callbacks. */
1146 (void) me->get_property ("direction");
1147 (void) me->get_property ("beaming");
1149 SCM posns = me->get_property ("positions");
1151 extract_grob_set (me, "stems", stems);
1156 for (int a = 2; a--;)
1157 common[a] = common_refpoint_of_array (stems, me, Axis (a));
1159 Drul_array<Real> pos = ly_scm2realdrul (posns);
1160 Real staff_space = Staff_symbol_referencer::staff_space (me);
1161 scale_drul (&pos, staff_space);
1165 if (robust_scm2int (me->get_property ("gap-count"), 0))
1168 thick = get_thickness (me);
1171 Grob *fvs = first_visible_stem (me);
1172 Grob *lvs = last_visible_stem (me);
1174 Real xl = fvs ? fvs->relative_coordinate (common[X_AXIS], X_AXIS) : 0.0;
1175 Real xr = lvs ? lvs->relative_coordinate (common[X_AXIS], X_AXIS) : 0.0;
1177 for (vsize i = 0; i < stems.size (); i++)
1181 bool french = to_boolean (s->get_property ("french-beaming"));
1182 Real stem_y = calc_stem_y (me, s, common,
1184 pos, french && s != lvs && s!= fvs);
1187 Make the stems go up to the end of the beam. This doesn't matter
1188 for normal beams, but for tremolo beams it looks silly otherwise.
1191 && !Stem::is_invisible (s))
1192 stem_y += thick * 0.5 * get_grob_direction (s);
1195 Do set_stemend for invisible stems too, so tuplet brackets
1196 have a reference point for sloping
1198 Stem::set_stemend (s, 2 * stem_y / staff_space);
1205 Beam::set_beaming (Grob *me, Beaming_pattern const *beaming)
1207 extract_grob_set (me, "stems", stems);
1210 for (vsize i = 0; i < stems.size (); i++)
1213 Don't overwrite user settings.
1217 Grob *stem = stems[i];
1218 SCM beaming_prop = stem->get_property ("beaming");
1219 if (beaming_prop == SCM_EOL
1220 || index_get_cell (beaming_prop, d) == SCM_EOL)
1222 int count = beaming->beamlet_count (i, d);
1224 && i < stems.size () -1
1225 && Stem::is_invisible (stem))
1226 count = min (count, beaming->beamlet_count (i,-d));
1228 if ( ((i == 0 && d == LEFT)
1229 || (i == stems.size ()-1 && d == RIGHT))
1230 && stems.size () > 1
1231 && to_boolean (me->get_property ("clip-edges")))
1234 Stem::set_beaming (stem, count, d);
1237 while (flip (&d) != LEFT);
1242 Beam::forced_stem_count (Grob *me)
1244 extract_grob_set (me, "stems", stems);
1247 for (vsize i = 0; i < stems.size (); i++)
1251 if (Stem::is_invisible (s))
1254 /* I can imagine counting those boundaries as a half forced stem,
1255 but let's count them full for now. */
1256 Direction defdir = to_dir (s->get_property ("default-direction"));
1258 if (abs (Stem::chord_start_y (s)) > 0.1
1260 && get_grob_direction (s) != defdir)
1267 Beam::visible_stem_count (Grob *me)
1269 extract_grob_set (me, "stems", stems);
1271 for (vsize i = stems.size (); i--;)
1273 if (!Stem::is_invisible (stems[i]))
1280 Beam::first_visible_stem (Grob *me)
1282 extract_grob_set (me, "stems", stems);
1284 for (vsize i = 0; i < stems.size (); i++)
1286 if (!Stem::is_invisible (stems[i]))
1293 Beam::last_visible_stem (Grob *me)
1295 extract_grob_set (me, "stems", stems);
1297 for (vsize i = stems.size (); i--;)
1299 if (!Stem::is_invisible (stems[i]))
1308 handle rest under beam (do_post: beams are calculated now)
1309 what about combination of collisions and rest under beam.
1313 rest -> stem -> beam -> interpolate_y_position ()
1315 MAKE_SCHEME_CALLBACK_WITH_OPTARGS (Beam, rest_collision_callback, 2, 1);
1317 Beam::rest_collision_callback (SCM smob, SCM prev_offset)
1319 Grob *rest = unsmob_grob (smob);
1320 if (scm_is_number (rest->get_property ("staff-position")))
1321 return scm_from_int (0);
1323 Real offset = robust_scm2double (prev_offset, 0.0);
1325 Grob *st = unsmob_grob (rest->get_object ("stem"));
1328 return scm_from_double (0.0);
1329 Grob *beam = unsmob_grob (stem->get_object ("beam"));
1331 || !Beam::has_interface (beam)
1332 || !Beam::visible_stem_count (beam))
1333 return scm_from_double (0.0);
1335 Drul_array<Real> pos (0, 0);
1336 SCM s = beam->get_property ("positions");
1337 if (scm_is_pair (s) && scm_is_number (scm_car (s)))
1338 pos = ly_scm2interval (s);
1340 programming_error ("positions property should always be pair of numbers.");
1342 Real staff_space = Staff_symbol_referencer::staff_space (rest);
1344 scale_drul (&pos, staff_space);
1346 Real dy = pos[RIGHT] - pos[LEFT];
1348 Drul_array<Grob*> visible_stems (first_visible_stem (beam),
1349 last_visible_stem (beam));
1350 extract_grob_set (beam, "stems", stems);
1352 Grob *common = common_refpoint_of_array (stems, beam, X_AXIS);
1354 Real x0 = visible_stems[LEFT]->relative_coordinate (common, X_AXIS);
1355 Real dx = visible_stems[RIGHT]->relative_coordinate (common, X_AXIS) - x0;
1356 Real slope = dy && dx ? dy / dx : 0;
1358 Direction d = get_grob_direction (stem);
1359 Real stem_y = pos[LEFT]
1360 + (stem->relative_coordinate (common, X_AXIS) - x0) * slope;
1362 Real beam_translation = get_beam_translation (beam);
1363 Real beam_thickness = Beam::get_thickness (beam);
1366 TODO: this is not strictly correct for 16th knee beams.
1369 = Stem::beam_multiplicity (stem).length () + 1;
1371 Real height_of_my_beams = beam_thickness / 2
1372 + (beam_count - 1) * beam_translation;
1373 Real beam_y = stem_y - d * height_of_my_beams;
1375 Grob *common_y = rest->common_refpoint (beam, Y_AXIS);
1376 Interval rest_extent = rest->extent (common_y, Y_AXIS);
1377 rest_extent.translate (offset);
1379 Real rest_dim = rest_extent[d];
1380 Real minimum_distance
1381 = staff_space * (robust_scm2double (stem->get_property ("stemlet-length"), 0.0)
1382 + robust_scm2double (rest->get_property ("minimum-distance"), 0.0));
1384 Real shift = d * min (((beam_y - d * minimum_distance) - rest_dim) * d, 0.0);
1386 shift /= staff_space;
1387 Real rad = Staff_symbol_referencer::line_count (rest) * staff_space / 2;
1389 /* Always move discretely by half spaces */
1390 shift = ceil (fabs (shift * 2.0)) / 2.0 * sign (shift);
1392 /* Inside staff, move by whole spaces*/
1393 if ((rest_extent[d] + staff_space * shift) * d
1395 || (rest_extent[-d] + staff_space * shift) * -d
1397 shift = ceil (fabs (shift)) * sign (shift);
1399 return scm_from_double (staff_space * shift);
1403 Beam::is_knee (Grob *me)
1405 SCM k = me->get_property ("knee");
1406 if (scm_is_bool (k))
1407 return ly_scm2bool (k);
1411 extract_grob_set (me, "stems", stems);
1412 for (vsize i = stems.size (); i--;)
1414 Direction dir = get_grob_direction (stems[i]);
1423 me->set_property ("knee", ly_bool2scm (knee));
1429 Beam::get_direction_beam_count (Grob *me, Direction d)
1431 extract_grob_set (me, "stems", stems);
1434 for (vsize i = stems.size (); i--;)
1437 Should we take invisible stems into account?
1439 if (get_grob_direction (stems[i]) == d)
1440 bc = max (bc, (Stem::beam_multiplicity (stems[i]).length () + 1));
1446 ADD_INTERFACE (Beam,
1450 "The @code{thickness} property is the weight of beams, "
1451 "measured in staffspace. The @code{direction} "
1452 "property is not user-serviceable. Use "
1453 "the @code{direction} property of @code{Stem} instead. "
1459 "beamed-stem-shorten "
1474 "neutral-direction "
1477 "quantized-positions "