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;
269 FIXME: what's this for?
271 SCM s = scm_cdr (this_beaming);
272 for (; scm_is_pair (s); s = scm_cdr (s))
274 int np = -this_dir * scm_to_int (scm_car (s));
275 scm_set_car_x (s, scm_from_int (np));
276 last_int.add_point (np);
280 if (scm_ilength (scm_cdr (this_beaming)) > 0)
282 last_beaming = this_beaming;
291 operator <(Beam_stem_segment const &a,
292 Beam_stem_segment const &b)
294 return a.rank_ < b.rank_;
297 typedef map<int, vector<Beam_stem_segment> > Position_stem_segments_map;
300 Beam::get_beam_segments (Grob *me_grob, Grob **common)
302 /* ugh, this has a side-effect that we need to ensure that
303 Stem #'beaming is correct */
304 (void) me_grob->get_property ("quantized-positions");
306 Spanner *me = dynamic_cast<Spanner*> (me_grob);
308 extract_grob_set (me, "stems", stems);
309 Grob *commonx = common_refpoint_of_array (stems, me, X_AXIS);
311 commonx = me->get_bound (LEFT)->common_refpoint (commonx, X_AXIS);
312 commonx = me->get_bound (RIGHT)->common_refpoint (commonx, X_AXIS);
316 int gap_count = robust_scm2int (me->get_property ("gap-count"), 0);
317 Real gap_length = robust_scm2double (me->get_property ("gap"), 0.0);
319 Position_stem_segments_map stem_segments;
320 Real lt = me->layout ()->get_dimension (ly_symbol2scm ("line-thickness"));
324 for (vsize i = 0; i < stems.size (); i++)
326 Grob *stem = stems[i];
327 Real stem_width = robust_scm2double (stem->get_property ("thickness"), 1.0) * lt;
328 Real stem_x = stem->relative_coordinate (commonx, X_AXIS);
329 SCM beaming = stem->get_property ("beaming");
333 for (SCM s = index_get_cell (beaming, d);
334 scm_is_pair (s); s = scm_cdr (s))
336 if (!scm_is_integer (scm_car (s)))
339 int beam_rank = scm_to_int (scm_car (s));
340 ranks.add_point (beam_rank);
343 for (SCM s = index_get_cell (beaming, d);
344 scm_is_pair (s); s = scm_cdr (s))
346 if (!scm_is_integer (scm_car (s)))
349 int beam_rank = scm_to_int (scm_car (s));
350 Beam_stem_segment seg;
352 seg.stem_x_ = stem_x;
353 seg.rank_ = 2 * i + (d+1)/2;
354 seg.width_ = stem_width;
357 seg.max_connect_ = robust_scm2int (stem->get_property ("max-beam-connect"), 1000);
359 Direction stem_dir = get_grob_direction (stem);
362 = (stem_dir * beam_rank < (stem_dir * ranks[-stem_dir] + gap_count));
363 stem_segments[beam_rank].push_back (seg);
366 while (flip (&d) != LEFT);
369 Drul_array<Real> break_overshoot
370 = robust_scm2drul (me->get_property ("break-overshoot"),
371 Drul_array<Real> (-0.5, 0.0));
373 vector<Beam_segment> segments;
374 for (Position_stem_segments_map::const_iterator i (stem_segments.begin ());
375 i != stem_segments.end (); i++)
377 vector<Beam_stem_segment> segs = (*i).second;
378 vector_sort (segs, less<Beam_stem_segment> ());
380 Beam_segment current;
382 int vertical_count = (*i).first;
383 for (vsize j = 0; j < segs.size (); j++)
386 event_dir == LEFT: left edge of a beamsegment.
388 Direction event_dir = LEFT;
391 bool on_bound = (event_dir == LEFT) ? j == 0 :
392 j == segs.size() - 1;
394 bool inside_stem = (event_dir == LEFT)
395 ? segs[j].stem_index_ > 0
396 : segs[j].stem_index_ < stems.size () - 1;
398 bool event = on_bound
399 || abs (segs[j].rank_ - segs[j+event_dir].rank_) > 1
400 || (abs (vertical_count) >= segs[j].max_connect_
401 || abs (vertical_count) >= segs[j + event_dir].max_connect_);
406 current.vertical_count_ = vertical_count;
407 current.horizontal_[event_dir] = segs[j].stem_x_;
408 if (segs[j].dir_ == event_dir)
411 && me->get_bound (event_dir)->break_status_dir ())
413 current.horizontal_[event_dir]
414 = (me->get_bound (event_dir)->extent (commonx, X_AXIS)[RIGHT]
415 + event_dir * break_overshoot[event_dir]);
419 Real notehead_width =
420 Stem::duration_log (segs[j].stem_) == 1
427 Grob *neighbor_stem = stems[segs[j].stem_index_ + event_dir];
428 Real neighbor_stem_x = neighbor_stem->relative_coordinate (commonx, X_AXIS);
430 notehead_width = min (notehead_width,
431 fabs (neighbor_stem_x - segs[j].stem_x_)/2);
433 current.horizontal_[event_dir] += event_dir * notehead_width;
438 current.horizontal_[event_dir] += event_dir * segs[j].width_/2;
440 current.horizontal_[event_dir] -= event_dir * gap_length;
443 if (event_dir == RIGHT)
445 segments.push_back (current);
446 current = Beam_segment();
449 while (flip (&event_dir) != LEFT);
457 MAKE_SCHEME_CALLBACK(Beam, print, 1);
459 Beam::print (SCM grob)
461 Spanner *me = unsmob_spanner (grob);
463 vector<Beam_segment> segments = get_beam_segments (me, &commonx);
466 if (visible_stem_count (me))
468 span[LEFT] = first_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
469 span[RIGHT] = last_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
473 extract_grob_set (me, "stems", stems);
474 span[LEFT] = stems[0]->relative_coordinate (commonx, X_AXIS);
475 span[RIGHT] = stems.back ()->relative_coordinate (commonx, X_AXIS);
478 Real blot = me->layout ()->get_dimension (ly_symbol2scm ("blot-diameter"));
480 SCM posns = me->get_property ("quantized-positions");
482 if (!is_number_pair (posns))
484 programming_error ("no beam positions?");
485 pos = Interval (0, 0);
488 pos = ly_scm2realdrul (posns);
490 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
492 Real dy = pos[RIGHT] - pos[LEFT];
493 Real slope = (dy && span.length ()) ? dy / span.length () : 0;
495 Real thick = get_thickness (me);
496 Real beam_dy = get_beam_translation (me);
498 Direction feather_dir = to_dir (me->get_property ("grow-direction"));
501 for (vsize i = 0; i < segments.size (); i ++)
503 Real local_slope = slope;
506 local_slope += feather_dir * segments[i].vertical_count_ * beam_dy / span.length ();
509 Stencil b = Lookup::beam (local_slope, segments[i].horizontal_.length (), thick, blot);
511 b.translate_axis (segments[i].horizontal_[LEFT], X_AXIS);
513 b.translate_axis (local_slope
514 * (segments[i].horizontal_[LEFT] - span.linear_combination (feather_dir))
515 + pos.linear_combination (feather_dir)
516 + beam_dy * segments[i].vertical_count_, Y_AXIS);
517 the_beam.add_stencil (b);
520 #if (DEBUG_BEAM_SCORING)
521 SCM quant_score = me->get_property ("quant-score");
522 SCM debug = me->layout ()->lookup_variable (ly_symbol2scm ("debug-beam-scoring"));
523 if (to_boolean (debug) && scm_is_string (quant_score))
525 extract_grob_set (me, "stems", stems);
528 This code prints the demerits for each beam. Perhaps this
529 should be switchable for those who want to twiddle with the
533 SCM properties = Font_interface::text_font_alist_chain (me);
535 Direction stem_dir = stems.size () ? to_dir (stems[0]->get_property ("direction")) : UP;
537 Stencil score = *unsmob_stencil (Text_interface::interpret_markup
538 (me->layout ()->self_scm (), properties, quant_score));
540 if (!score.is_empty ())
541 the_beam.add_at_edge (Y_AXIS, stem_dir, score, 1.0, 0);
545 the_beam.translate_axis (-me->relative_coordinate (commonx, X_AXIS), X_AXIS);
546 return the_beam.smobbed_copy ();
550 Beam::get_default_dir (Grob *me)
552 extract_grob_set (me, "stems", stems);
554 Drul_array<Real> extremes (0.0, 0.0);
555 for (iterof (s, stems); s != stems.end (); s++)
557 Interval positions = Stem::head_positions (*s);
561 if (sign (positions[d]) == d)
562 extremes[d] = d * max (d * positions[d], d * extremes[d]);
564 while (flip (&d) != DOWN);
567 Drul_array<int> total (0, 0);
568 Drul_array<int> count (0, 0);
570 bool force_dir = false;
571 for (vsize i = 0; i < stems.size (); i++)
574 Direction stem_dir = CENTER;
575 SCM stem_dir_scm = s->get_property_data ("direction");
576 if (is_direction (stem_dir_scm))
578 stem_dir = to_dir (stem_dir_scm);
582 stem_dir = to_dir (s->get_property ("default-direction"));
585 stem_dir = to_dir (s->get_property ("neutral-direction"));
590 total[stem_dir] += max (int (- stem_dir * Stem::head_positions (s) [-stem_dir]), 0);
597 if (abs (extremes[UP]) > -extremes[DOWN])
599 else if (extremes[UP] < -extremes[DOWN])
603 Direction dir = CENTER;
604 Direction d = CENTER;
605 if ((d = (Direction) sign (count[UP] - count[DOWN])))
609 && (d = (Direction) sign (total[UP] / count[UP] - total[DOWN]/count[DOWN])))
611 else if ((d = (Direction) sign (total[UP] - total[DOWN])))
614 dir = to_dir (me->get_property ("neutral-direction"));
619 /* Set all stems with non-forced direction to beam direction.
620 Urg: non-forced should become `without/with unforced' direction,
621 once stem gets cleaned-up. */
623 Beam::set_stem_directions (Grob *me, Direction d)
625 extract_grob_set (me, "stems", stems);
627 for (vsize i = 0; i < stems.size (); i++)
631 SCM forcedir = s->get_property_data ("direction");
632 if (!to_dir (forcedir))
633 set_grob_direction (s, d);
638 Only try horizontal beams for knees. No reliable detection of
639 anything else is possible here, since we don't know funky-beaming
640 settings, or X-distances (slopes!) People that want sloped
641 knee-beams, should set the directions manually.
646 this routine should take into account the stemlength scoring
647 of a possible knee/nonknee beam.
650 Beam::consider_auto_knees (Grob *me)
652 SCM scm = me->get_property ("auto-knee-gap");
653 if (!scm_is_number (scm))
660 extract_grob_set (me, "stems", stems);
662 Grob *common = common_refpoint_of_array (stems, me, Y_AXIS);
663 Real staff_space = Staff_symbol_referencer::staff_space (me);
665 vector<Interval> head_extents_array;
666 for (vsize i = 0; i < stems.size (); i++)
668 Grob *stem = stems[i];
669 if (Stem::is_invisible (stem))
672 Interval head_extents = Stem::head_positions (stem);
673 if (!head_extents.is_empty ())
675 head_extents[LEFT] += -1;
676 head_extents[RIGHT] += 1;
677 head_extents *= staff_space * 0.5;
680 We could subtract beam Y position, but this routine only
681 sets stem directions, a constant shift does not have an
684 head_extents += stem->relative_coordinate (common, Y_AXIS);
686 if (to_dir (stem->get_property_data ("direction")))
688 Direction stemdir = to_dir (stem->get_property ("direction"));
689 head_extents[-stemdir] = -stemdir * infinity_f;
692 head_extents_array.push_back (head_extents);
694 gaps.remove_interval (head_extents);
698 Real max_gap_len = 0.0;
700 for (vsize i = gaps.allowed_regions_.size () -1; i != VPOS ;i--)
702 Interval gap = gaps.allowed_regions_[i];
705 the outer gaps are not knees.
707 if (isinf (gap[LEFT]) || isinf (gap[RIGHT]))
710 if (gap.length () >= max_gap_len)
712 max_gap_len = gap.length ();
717 Real beam_translation = get_beam_translation (me);
718 Real beam_thickness = Beam::get_thickness (me);
719 int beam_count = Beam::get_beam_count (me);
720 Real height_of_beams = beam_thickness / 2
721 + (beam_count - 1) * beam_translation;
722 Real threshold = scm_to_double (scm) + height_of_beams;
724 if (max_gap_len > threshold)
727 for (vsize i = 0; i < stems.size (); i++)
729 Grob *stem = stems[i];
730 if (Stem::is_invisible (stem))
733 Interval head_extents = head_extents_array[j++];
735 Direction d = (head_extents.center () < max_gap.center ())
738 stem->set_property ("direction", scm_from_int (d));
740 head_extents.intersect (max_gap);
741 assert (head_extents.is_empty () || head_extents.length () < 1e-6);
746 /* Set stem's shorten property if unset.
749 take some y-position (chord/beam/nearest?) into account
750 scmify forced-fraction
752 This is done in beam because the shorten has to be uniform over the
759 set_minimum_dy (Grob *me, Real *dy)
764 If dy is smaller than the smallest quant, we
765 get absurd direction-sign penalties.
768 Real ss = Staff_symbol_referencer::staff_space (me);
769 Real thickness = Beam::get_thickness (me) / ss;
770 Real slt = Staff_symbol_referencer::line_thickness (me) / ss;
771 Real sit = (thickness - slt) / 2;
773 Real hang = 1.0 - (thickness - slt) / 2;
775 *dy = sign (*dy) * max (fabs (*dy),
776 min (min (sit, inter), hang));
782 MAKE_SCHEME_CALLBACK(Beam, calc_stem_shorten, 1)
784 Beam::calc_stem_shorten (SCM smob)
786 Grob *me = unsmob_grob (smob);
789 shortening looks silly for x staff beams
792 return scm_from_int (0);
794 Real forced_fraction = 1.0 * forced_stem_count (me)
795 / visible_stem_count (me);
797 int beam_count = get_beam_count (me);
799 SCM shorten_list = me->get_property ("beamed-stem-shorten");
800 if (shorten_list == SCM_EOL)
801 return scm_from_int (0);
803 Real staff_space = Staff_symbol_referencer::staff_space (me);
806 = robust_list_ref (beam_count -1, shorten_list);
807 Real shorten = scm_to_double (shorten_elt) * staff_space;
809 shorten *= forced_fraction;
813 return scm_from_double (shorten);
815 return scm_from_double (0.0);
821 Compute a first approximation to the beam slope.
823 MAKE_SCHEME_CALLBACK (Beam, calc_least_squares_positions, 2);
825 Beam::calc_least_squares_positions (SCM smob, SCM posns)
829 Grob *me = unsmob_grob (smob);
831 int count = visible_stem_count (me);
834 return ly_interval2scm (pos);
836 vector<Real> x_posns;
837 extract_grob_set (me, "stems", stems);
838 Grob *commonx = common_refpoint_of_array (stems, me, X_AXIS);
839 Grob *commony = common_refpoint_of_array (stems, me, Y_AXIS);
841 Real my_y = me->relative_coordinate (commony, Y_AXIS);
843 Grob *fvs = first_visible_stem (me);
844 Grob *lvs = last_visible_stem (me);
846 Interval ideal (Stem::get_stem_info (fvs).ideal_y_
847 + fvs->relative_coordinate (commony, Y_AXIS) - my_y,
848 Stem::get_stem_info (lvs).ideal_y_
849 + lvs->relative_coordinate (commony, Y_AXIS) - my_y);
851 Real x0 = first_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
852 for (vsize i = 0; i < stems.size (); i++)
856 Real x = s->relative_coordinate (commonx, X_AXIS) - x0;
857 x_posns.push_back (x);
859 Real dx = last_visible_stem (me)->relative_coordinate (commonx, X_AXIS) - x0;
867 Interval chord (Stem::chord_start_y (first_visible_stem (me)),
868 Stem::chord_start_y (last_visible_stem (me)));
870 /* Simple beams (2 stems) on middle line should be allowed to be
873 However, if both stems reach middle line,
874 ideal[LEFT] == ideal[RIGHT] and ideal.delta () == 0.
876 For that case, we apply artificial slope */
877 if (!ideal[LEFT] && chord.delta () && count == 2)
880 Direction d = (Direction) (sign (chord.delta ()) * UP);
881 pos[d] = get_thickness (me) / 2;
888 For broken beams this doesn't work well. In this case, the
889 slope esp. of the first part of a broken beam should predict
890 where the second part goes.
892 ldy = pos[RIGHT] - pos[LEFT];
896 vector<Offset> ideals;
897 for (vsize i = 0; i < stems.size (); i++)
900 if (!Stem::is_normal_stem (s))
903 ideals.push_back (Offset (x_posns[i],
904 Stem::get_stem_info (s).ideal_y_
905 + s->relative_coordinate (commony, Y_AXIS)
909 minimise_least_squares (&slope, &y, ideals);
913 set_minimum_dy (me, &dy);
916 pos = Interval (y, (y + dy));
920 "position" is relative to the staff.
922 scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
924 me->set_property ("least-squares-dy", scm_from_double (ldy));
925 return ly_interval2scm (pos);
929 We can't combine with previous function, since check concave and
930 slope damping comes first.
932 TODO: we should use the concaveness to control the amount of damping
935 MAKE_SCHEME_CALLBACK (Beam, shift_region_to_valid, 2);
937 Beam::shift_region_to_valid (SCM grob, SCM posns)
939 Grob *me = unsmob_grob (grob);
943 vector<Real> x_posns;
944 extract_grob_set (me, "stems", stems);
945 Grob *commonx = common_refpoint_of_array (stems, me, X_AXIS);
946 Grob *commony = common_refpoint_of_array (stems, me, Y_AXIS);
948 Grob *fvs = first_visible_stem (me);
953 Real x0 = fvs->relative_coordinate (commonx, X_AXIS);
954 for (vsize i = 0; i < stems.size (); i++)
958 Real x = s->relative_coordinate (commonx, X_AXIS) - x0;
959 x_posns.push_back (x);
962 Grob *lvs = last_visible_stem (me);
966 Real dx = lvs->relative_coordinate (commonx, X_AXIS) - x0;
968 Drul_array<Real> pos = ly_scm2interval (posns);
971 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
973 Real dy = pos[RIGHT] - pos[LEFT];
975 Real slope = dx ? (dy / dx) : 0.0;
978 Shift the positions so that we have a chance of finding good
979 quants (i.e. no short stem failures.)
981 Interval feasible_left_point;
982 feasible_left_point.set_full ();
983 for (vsize i = 0; i < stems.size (); i++)
986 if (Stem::is_invisible (s))
989 Direction d = get_grob_direction (s);
992 = Stem::get_stem_info (s).shortest_y_
993 - slope * x_posns [i];
996 left_y is now relative to the stem S. We want relative to
997 ourselves, so translate:
1000 += + s->relative_coordinate (commony, Y_AXIS)
1001 - me->relative_coordinate (commony, Y_AXIS);
1007 feasible_left_point.intersect (flp);
1010 if (feasible_left_point.is_empty ())
1011 warning (_ ("no viable initial configuration found: may not find good beam slope"));
1012 else if (!feasible_left_point.contains (y))
1014 const int REGION_SIZE = 2; // UGH UGH
1015 if (isinf (feasible_left_point[DOWN]))
1016 y = feasible_left_point[UP] - REGION_SIZE;
1017 else if (isinf (feasible_left_point[UP]))
1018 y = feasible_left_point[DOWN]+ REGION_SIZE;
1020 y = feasible_left_point.center ();
1023 pos = Drul_array<Real> (y, (y + dy));
1024 scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
1026 return ly_interval2scm (pos);
1029 /* This neat trick is by Werner Lemberg,
1030 damped = tanh (slope)
1031 corresponds with some tables in [Wanske] CHECKME */
1032 MAKE_SCHEME_CALLBACK (Beam, slope_damping, 2);
1034 Beam::slope_damping (SCM smob, SCM posns)
1036 Grob *me = unsmob_grob (smob);
1037 Drul_array<Real> pos = ly_scm2interval (posns);
1039 if (visible_stem_count (me) <= 1)
1043 SCM s = me->get_property ("damping");
1044 Real damping = scm_to_double (s);
1045 Real concaveness = robust_scm2double (me->get_property ("concaveness"), 0.0);
1046 if (concaveness >= 10000)
1048 pos[LEFT] = pos[RIGHT];
1049 me->set_property ("least-squares-dy", scm_from_double (0));
1055 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
1057 Real dy = pos[RIGHT] - pos[LEFT];
1059 Grob *fvs = first_visible_stem (me);
1060 Grob *lvs = last_visible_stem (me);
1062 Grob *commonx = fvs->common_refpoint (lvs, X_AXIS);
1064 Real dx = last_visible_stem (me)->relative_coordinate (commonx, X_AXIS)
1065 - first_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
1067 Real slope = dy && dx ? dy / dx : 0;
1069 slope = 0.6 * tanh (slope) / (damping + concaveness);
1071 Real damped_dy = slope * dx;
1073 set_minimum_dy (me, &damped_dy);
1075 pos[LEFT] += (dy - damped_dy) / 2;
1076 pos[RIGHT] -= (dy - damped_dy) / 2;
1078 scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
1081 return ly_interval2scm (pos);
1085 Report slice containing the numbers that are both in (car BEAMING)
1089 where_are_the_whole_beams (SCM beaming)
1093 for (SCM s = scm_car (beaming); scm_is_pair (s); s = scm_cdr (s))
1095 if (scm_c_memq (scm_car (s), scm_cdr (beaming)) != SCM_BOOL_F)
1097 l.add_point (scm_to_int (scm_car (s)));
1103 /* Return the Y position of the stem-end, given the Y-left, Y-right
1104 in POS for stem S. This Y position is relative to S. */
1106 Beam::calc_stem_y (Grob *me, Grob *stem, Grob **common,
1108 Drul_array<Real> pos, bool french)
1110 Real beam_translation = get_beam_translation (me);
1112 Real r = stem->relative_coordinate (common[X_AXIS], X_AXIS) - xl;
1113 Real dy = pos[RIGHT] - pos[LEFT];
1115 Real stem_y_beam0 = (dy && dx
1120 Direction my_dir = get_grob_direction (stem);
1121 SCM beaming = stem->get_property ("beaming");
1123 Real stem_y = stem_y_beam0;
1126 Slice bm = where_are_the_whole_beams (beaming);
1127 if (!bm.is_empty ())
1128 stem_y += beam_translation * bm[-my_dir];
1132 Slice bm = Stem::beam_multiplicity (stem);
1133 if (!bm.is_empty ())
1134 stem_y += bm[my_dir] * beam_translation;
1137 Real id = me->relative_coordinate (common[Y_AXIS], Y_AXIS)
1138 - stem->relative_coordinate (common[Y_AXIS], Y_AXIS);
1144 Hmm. At this time, beam position and slope are determined. Maybe,
1145 stem directions and length should set to relative to the chord's
1146 position of the beam. */
1147 MAKE_SCHEME_CALLBACK(Beam, set_stem_lengths, 1);
1149 Beam::set_stem_lengths (SCM smob)
1151 Grob *me = unsmob_grob (smob);
1153 /* trigger callbacks. */
1154 (void) me->get_property ("direction");
1155 (void) me->get_property ("beaming");
1157 SCM posns = me->get_property ("positions");
1159 extract_grob_set (me, "stems", stems);
1164 for (int a = 2; a--;)
1165 common[a] = common_refpoint_of_array (stems, me, Axis (a));
1167 Drul_array<Real> pos = ly_scm2realdrul (posns);
1168 Real staff_space = Staff_symbol_referencer::staff_space (me);
1169 scale_drul (&pos, staff_space);
1173 if (robust_scm2int (me->get_property ("gap-count"), 0))
1176 thick = get_thickness (me);
1179 Grob *fvs = first_visible_stem (me);
1180 Grob *lvs = last_visible_stem (me);
1182 Real xl = fvs ? fvs->relative_coordinate (common[X_AXIS], X_AXIS) : 0.0;
1183 Real xr = lvs ? lvs->relative_coordinate (common[X_AXIS], X_AXIS) : 0.0;
1185 for (vsize i = 0; i < stems.size (); i++)
1189 bool french = to_boolean (s->get_property ("french-beaming"));
1190 Real stem_y = calc_stem_y (me, s, common,
1192 pos, french && s != lvs && s!= fvs);
1195 Make the stems go up to the end of the beam. This doesn't matter
1196 for normal beams, but for tremolo beams it looks silly otherwise.
1199 && !Stem::is_invisible (s))
1200 stem_y += thick * 0.5 * get_grob_direction (s);
1203 Do set_stemend for invisible stems too, so tuplet brackets
1204 have a reference point for sloping
1206 Stem::set_stemend (s, 2 * stem_y / staff_space);
1213 Beam::set_beaming (Grob *me, Beaming_pattern const *beaming)
1215 extract_grob_set (me, "stems", stems);
1218 for (vsize i = 0; i < stems.size (); i++)
1221 Don't overwrite user settings.
1225 Grob *stem = stems[i];
1226 SCM beaming_prop = stem->get_property ("beaming");
1227 if (beaming_prop == SCM_EOL
1228 || index_get_cell (beaming_prop, d) == SCM_EOL)
1230 int count = beaming->beamlet_count (i, d);
1232 && i < stems.size () -1
1233 && Stem::is_invisible (stem))
1234 count = min (count, beaming->beamlet_count (i,-d));
1236 if ( ((i == 0 && d == LEFT)
1237 || (i == stems.size ()-1 && d == RIGHT))
1238 && stems.size () > 1
1239 && to_boolean (me->get_property ("clip-edges")))
1242 Stem::set_beaming (stem, count, d);
1245 while (flip (&d) != LEFT);
1250 Beam::forced_stem_count (Grob *me)
1252 extract_grob_set (me, "stems", stems);
1255 for (vsize i = 0; i < stems.size (); i++)
1259 if (Stem::is_invisible (s))
1262 /* I can imagine counting those boundaries as a half forced stem,
1263 but let's count them full for now. */
1264 Direction defdir = to_dir (s->get_property ("default-direction"));
1266 if (abs (Stem::chord_start_y (s)) > 0.1
1268 && get_grob_direction (s) != defdir)
1275 Beam::visible_stem_count (Grob *me)
1277 extract_grob_set (me, "stems", stems);
1279 for (vsize i = stems.size (); i--;)
1281 if (!Stem::is_invisible (stems[i]))
1288 Beam::first_visible_stem (Grob *me)
1290 extract_grob_set (me, "stems", stems);
1292 for (vsize i = 0; i < stems.size (); i++)
1294 if (Stem::is_normal_stem (stems[i]))
1301 Beam::last_visible_stem (Grob *me)
1303 extract_grob_set (me, "stems", stems);
1305 for (vsize i = stems.size (); i--;)
1307 if (Stem::is_normal_stem (stems[i]))
1316 handle rest under beam (do_post: beams are calculated now)
1317 what about combination of collisions and rest under beam.
1321 rest -> stem -> beam -> interpolate_y_position ()
1323 MAKE_SCHEME_CALLBACK_WITH_OPTARGS (Beam, rest_collision_callback, 2, 1);
1325 Beam::rest_collision_callback (SCM smob, SCM prev_offset)
1327 Grob *rest = unsmob_grob (smob);
1328 if (scm_is_number (rest->get_property ("staff-position")))
1329 return scm_from_int (0);
1331 Real offset = robust_scm2double (prev_offset, 0.0);
1333 Grob *st = unsmob_grob (rest->get_object ("stem"));
1336 return scm_from_double (0.0);
1337 Grob *beam = unsmob_grob (stem->get_object ("beam"));
1339 || !Beam::has_interface (beam)
1340 || !Beam::visible_stem_count (beam))
1341 return scm_from_double (0.0);
1343 Drul_array<Real> pos (robust_scm2drul (beam->get_property ("positions"),
1344 Drul_array<Real> (0,0)));
1346 Real staff_space = Staff_symbol_referencer::staff_space (rest);
1348 scale_drul (&pos, staff_space);
1350 Real dy = pos[RIGHT] - pos[LEFT];
1352 Drul_array<Grob*> visible_stems (first_visible_stem (beam),
1353 last_visible_stem (beam));
1354 extract_grob_set (beam, "stems", stems);
1356 Grob *common = common_refpoint_of_array (stems, beam, X_AXIS);
1358 Real x0 = visible_stems[LEFT]->relative_coordinate (common, X_AXIS);
1359 Real dx = visible_stems[RIGHT]->relative_coordinate (common, X_AXIS) - x0;
1360 Real slope = dy && dx ? dy / dx : 0;
1362 Direction d = get_grob_direction (stem);
1363 Real stem_y = pos[LEFT]
1364 + (stem->relative_coordinate (common, X_AXIS) - x0) * slope;
1366 Real beam_translation = get_beam_translation (beam);
1367 Real beam_thickness = Beam::get_thickness (beam);
1370 TODO: this is not strictly correct for 16th knee beams.
1373 = Stem::beam_multiplicity (stem).length () + 1;
1375 Real height_of_my_beams = beam_thickness / 2
1376 + (beam_count - 1) * beam_translation;
1377 Real beam_y = stem_y - d * height_of_my_beams;
1379 Grob *common_y = rest->common_refpoint (beam, Y_AXIS);
1382 TODO: this is dubious, because this call needs the info we're
1383 computing right now.
1385 Interval rest_extent = rest->extent (common_y, Y_AXIS);
1386 rest_extent.translate (offset);
1388 Real rest_dim = rest_extent[d];
1389 Real minimum_distance
1390 = staff_space * (robust_scm2double (stem->get_property ("stemlet-length"), 0.0)
1391 + robust_scm2double (rest->get_property ("minimum-distance"), 0.0));
1393 Real shift = d * min (d * (beam_y - d * minimum_distance - rest_dim), 0.0);
1395 shift /= staff_space;
1396 Real rad = Staff_symbol_referencer::line_count (rest) * staff_space / 2;
1398 /* Always move discretely by half spaces */
1399 shift = ceil (fabs (shift * 2.0)) / 2.0 * sign (shift);
1401 /* Inside staff, move by whole spaces*/
1402 if ((rest_extent[d] + staff_space * shift) * d
1404 || (rest_extent[-d] + staff_space * shift) * -d
1406 shift = ceil (fabs (shift)) * sign (shift);
1408 return scm_from_double (offset + staff_space * shift);
1412 Beam::is_knee (Grob *me)
1414 SCM k = me->get_property ("knee");
1415 if (scm_is_bool (k))
1416 return ly_scm2bool (k);
1420 extract_grob_set (me, "stems", stems);
1421 for (vsize i = stems.size (); i--;)
1423 Direction dir = get_grob_direction (stems[i]);
1432 me->set_property ("knee", ly_bool2scm (knee));
1438 Beam::get_direction_beam_count (Grob *me, Direction d)
1440 extract_grob_set (me, "stems", stems);
1443 for (vsize i = stems.size (); i--;)
1446 Should we take invisible stems into account?
1448 if (get_grob_direction (stems[i]) == d)
1449 bc = max (bc, (Stem::beam_multiplicity (stems[i]).length () + 1));
1455 ADD_INTERFACE (Beam,
1458 "The @code{thickness} property is the weight of beams, "
1459 "measured in staffspace. The @code{direction} "
1460 "property is not user-serviceable. Use "
1461 "the @code{direction} property of @code{Stem} instead. "
1467 "beamed-stem-shorten "
1482 "neutral-direction "
1485 "quantized-positions "