2 beam.cc -- implement Beam
4 source file of the GNU LilyPond music typesetter
6 (c) 1997--2005 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.
28 #include "interval-set.hh"
29 #include "directional-element-interface.hh"
32 #include "least-squares.hh"
34 #include "output-def.hh"
36 #include "pointer-group-interface.hh"
37 #include "staff-symbol-referencer.hh"
43 #include "text-interface.hh" // debug output.
44 #include "font-interface.hh" // debug output.
48 Beam::add_stem (Grob *me, Grob *s)
50 if (Stem::get_beam (s))
52 programming_error ("Stem already has beam");
56 Pointer_group_interface::add_grob (me, ly_symbol2scm ("stems"), s);
57 s->set_object ("beam", me->self_scm ());
58 add_bound_item (dynamic_cast<Spanner *> (me), dynamic_cast<Item *> (s));
62 Beam::get_thickness (Grob *me)
64 return robust_scm2double (me->get_property ("thickness"), 0)
65 * Staff_symbol_referencer::staff_space (me);
68 /* Return the translation between 2 adjoining beams. */
70 Beam::get_beam_translation (Grob *me)
72 int beam_count = get_beam_count (me);
73 Real staff_space = Staff_symbol_referencer::staff_space (me);
74 Real line = Staff_symbol_referencer::line_thickness (me);
75 Real thickness = get_thickness (me);
76 Real fract = robust_scm2double (me->get_property ("length-fraction"), 1.0);
78 Real beam_translation = beam_count < 4
79 ? (2 * staff_space + line - thickness) / 2.0
80 : (3 * staff_space + line - thickness) / 3.0;
82 return fract * beam_translation;
85 /* Maximum beam_count. */
87 Beam::get_beam_count (Grob *me)
91 extract_grob_set (me, "stems", stems);
92 for (int i = 0; i < stems.size (); i++)
94 Grob *stem = stems[i];
95 m = max (m, (Stem::beam_multiplicity (stem).length () + 1));
101 /* After pre-processing all directions should be set.
102 Several post-processing routines (stem, slur, script) need stem/beam
104 Currenly, this means that beam has set all stem's directions.
105 [Alternatively, stems could set its own directions, according to
106 their beam, during 'final-pre-processing'.] */
107 MAKE_SCHEME_CALLBACK (Beam, calc_direction, 1);
109 Beam::calc_direction (SCM smob)
111 Grob *me = unsmob_grob (smob);
113 /* Beams with less than 2 two stems don't make much sense, but could happen
118 For a beam that only has one stem, we try to do some disappearance magic:
119 we revert the flag, and move on to The Eternal Engraving Fields. */
121 Direction d = CENTER;
123 int count = visible_stem_count (me);
126 extract_grob_set (me, "stems", stems);
127 if (stems.size () == 1)
129 me->warning (_ ("removing beam with less than two stems"));
131 stems[0]->set_object ("beam", SCM_EOL);
134 return SCM_UNSPECIFIED;
136 else if (stems.size () == 0)
139 return SCM_UNSPECIFIED;
146 can happen in stem-tremolo case.
149 d = Stem::get_default_dir (stems[0]);
156 d = get_default_dir (me);
157 consider_auto_knees (me);
162 set_stem_directions (me, d);
165 return scm_from_int (d);
170 /* We want a maximal number of shared beams, but if there is choice, we
171 * take the one that is closest to the end of the stem. This is for
183 position_with_maximal_common_beams (SCM left_beaming, SCM right_beaming,
187 Slice lslice = int_list_to_slice (scm_cdr (left_beaming));
191 for (int i = lslice[-left_dir];
192 (i - lslice[left_dir]) * left_dir <= 0; i += left_dir)
195 for (SCM s = scm_car (right_beaming); scm_is_pair (s); s = scm_cdr (s))
197 int k = -right_dir * scm_to_int (scm_car (s)) + i;
198 if (scm_c_memq (scm_from_int (k), left_beaming) != SCM_BOOL_F)
202 if (count >= best_count)
212 MAKE_SCHEME_CALLBACK(Beam, calc_beaming, 1)
214 Beam::calc_beaming (SCM smob)
216 Grob *me = unsmob_grob (smob);
218 extract_grob_set (me, "stems", stems);
221 last_int.set_empty ();
223 SCM last_beaming = scm_cons (SCM_EOL, scm_list_1 (scm_from_int (0)));
224 Direction last_dir = CENTER;
225 for (int i = 0; i < stems.size (); i++)
227 Grob *this_stem = stems[i];
228 SCM this_beaming = this_stem->get_property ("beaming");
230 Direction this_dir = get_grob_direction (this_stem);
231 if (scm_is_pair (last_beaming) && scm_is_pair (this_beaming))
233 int start_point = position_with_maximal_common_beams
234 (last_beaming, this_beaming,
235 last_dir ? last_dir : this_dir,
242 new_slice.set_empty ();
243 SCM s = index_get_cell (this_beaming, d);
244 for (; scm_is_pair (s); s = scm_cdr (s))
247 = start_point - this_dir * scm_to_int (scm_car (s));
249 new_slice.add_point (new_beam_pos);
250 scm_set_car_x (s, scm_from_int (new_beam_pos));
253 while (flip (&d) != LEFT);
255 if (!new_slice.is_empty ())
256 last_int = new_slice;
260 SCM s = scm_cdr (this_beaming);
261 for (; scm_is_pair (s); s = scm_cdr (s))
263 int np = -this_dir * scm_to_int (scm_car (s));
264 scm_set_car_x (s, scm_from_int (np));
265 last_int.add_point (np);
269 if (scm_ilength (scm_cdr (this_beaming)) > 0)
271 last_beaming = this_beaming;
280 I really enjoy spaghetti, but spaghetti should be kept on a plate
281 with a little garlic and olive oil. This is too much.
285 MAKE_SCHEME_CALLBACK (Beam, print, 1);
287 Beam::print (SCM grob)
289 Spanner *me = unsmob_spanner (grob);
291 extract_grob_set (me, "stems", stems);
292 Grob *xcommon = common_refpoint_of_array (stems, me, X_AXIS);
294 xcommon = me->get_bound (LEFT)->common_refpoint (xcommon, X_AXIS);
295 xcommon = me->get_bound (RIGHT)->common_refpoint (xcommon, X_AXIS);
298 if (visible_stem_count (me))
300 // ugh -> use commonx
301 x0 = first_visible_stem (me)->relative_coordinate (xcommon, X_AXIS);
302 dx = last_visible_stem (me)->relative_coordinate (xcommon, X_AXIS) - x0;
306 x0 = stems[0]->relative_coordinate (xcommon, X_AXIS);
307 dx = stems.top ()->relative_coordinate (xcommon, X_AXIS) - x0;
310 SCM posns = me->get_property ("quantized-positions");
311 Drul_array<Real> pos;
312 if (!is_number_pair (posns))
314 programming_error ("no beam positions?");
315 pos = Interval (0, 0);
318 pos = ly_scm2realdrul (posns);
320 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
322 Real dy = pos[RIGHT] - pos[LEFT];
323 Real slope = (dy && dx) ? dy / dx : 0;
325 Real thick = get_thickness (me);
326 Real bdy = get_beam_translation (me);
328 SCM last_beaming = SCM_EOL;
329 Real last_xposn = -1;
330 Real last_stem_width = -1;
332 Real gap_length = robust_scm2double (me->get_property ("gap"), 0.0);
335 Real lt = me->layout ()->get_dimension (ly_symbol2scm ("linethickness"));
337 for (int i = 0; i <= stems.size (); i++)
339 Grob *stem = (i < stems.size ()) ? stems[i] : 0;
341 SCM this_beaming = stem ? stem->get_property ("beaming") : SCM_EOL;
342 Real xposn = stem ? stem->relative_coordinate (xcommon, X_AXIS) : 0.0;
343 Real stem_width = stem ? robust_scm2double (stem->get_property ("thickness"), 1.0) * lt : 0;
344 Direction stem_dir = stem ? to_dir (stem->get_property ("direction")) : CENTER;
346 We do the space left of ST, with lfliebertjes pointing to the
347 right from the left stem, and rfliebertjes pointing left from
350 SCM left = (i > 0) ? scm_cdr (last_beaming) : SCM_EOL;
351 SCM right = stem ? scm_car (this_beaming) : SCM_EOL;
353 Array<int> full_beams;
354 Array<int> lfliebertjes;
355 Array<int> rfliebertjes;
358 scm_is_pair (s); s = scm_cdr (s))
360 int b = scm_to_int (scm_car (s));
361 if (scm_c_memq (scm_car (s), right) != SCM_BOOL_F)
364 lfliebertjes.push (b);
367 scm_is_pair (s); s = scm_cdr (s))
369 int b = scm_to_int (scm_car (s));
370 if (scm_c_memq (scm_car (s), left) == SCM_BOOL_F)
371 rfliebertjes.push (b);
374 Drul_array<Real> break_overshoot
375 = robust_scm2drul (me->get_property ("break-overshoot"),
376 Drul_array<Real> (-0.5, 0.0));
378 Real w = (i > 0 && stem)
379 ? (xposn - last_xposn)
380 : break_overshoot[ (i == 0) ? LEFT : RIGHT];
382 Real stem_offset = 0.0;
385 w += last_stem_width / 2;
386 stem_offset = -last_stem_width / 2;
392 Real blot = me->layout ()->get_dimension (ly_symbol2scm ("blotdiameter"));
393 Stencil whole = Lookup::beam (slope, w, thick, blot);
397 if (scm_is_number (me->get_property ("gap-count")))
399 gap_count = scm_to_int (me->get_property ("gap-count"));
400 gapped = Lookup::beam (slope, w - 2 * gap_length, thick, blot);
402 full_beams.sort (default_compare);
404 full_beams.reverse ();
408 for (int j = full_beams.size (); j--;)
415 b.translate_axis (gap_length, X_AXIS);
417 b.translate_axis (last_xposn - x0 + stem_offset, X_AXIS);
418 b.translate_axis (slope * (last_xposn - x0) + bdy * full_beams[j], Y_AXIS);
420 the_beam.add_stencil (b);
423 if (lfliebertjes.size () || rfliebertjes.size ())
429 int t = Stem::duration_log (stem);
437 nw_f = break_overshoot[RIGHT] / 2;
439 /* Half beam should be one note-width,
440 but let's make sure two half-beams never touch */
444 rw = min (nw_f, ((xposn - last_xposn) / 2));
447 if (me->get_bound (LEFT)->break_status_dir ())
448 rw = xposn - me->get_bound (LEFT)->extent (xcommon, X_AXIS)[RIGHT]
449 + break_overshoot[LEFT];
455 lw = min (nw_f, ((xposn - last_xposn) / 2));
458 lw = me->get_bound (RIGHT)->relative_coordinate (xcommon, X_AXIS)
460 + break_overshoot[RIGHT];
462 rw += stem_width / 2;
463 lw += last_stem_width / 2;
465 Stencil rhalf = Lookup::beam (slope, rw, thick, blot);
466 Stencil lhalf = Lookup::beam (slope, lw, thick, blot);
467 for (int j = lfliebertjes.size (); j--;)
470 b.translate_axis (last_xposn - x0 - last_stem_width /2,
472 b.translate_axis (slope * (last_xposn - x0)
473 + bdy * lfliebertjes[j],
475 the_beam.add_stencil (b);
477 for (int j = rfliebertjes.size (); j--;)
480 b.translate_axis (xposn - x0 - rw + stem_width / 2, X_AXIS);
481 b.translate_axis (slope * (xposn - x0 - rw)
482 + bdy * rfliebertjes[j], Y_AXIS);
483 the_beam.add_stencil (b);
488 last_stem_width = stem_width;
489 last_beaming = this_beaming;
492 the_beam.translate_axis (x0 - me->relative_coordinate (xcommon, X_AXIS),
494 the_beam.translate_axis (pos[LEFT], Y_AXIS);
497 SCM quant_score = me->get_property ("quant-score");
498 SCM debug = me->layout ()->lookup_variable (ly_symbol2scm ("debug-beam-quanting"));
499 if (to_boolean (debug) && scm_is_string (quant_score))
503 This code prints the demerits for each beam. Perhaps this
504 should be switchable for those who want to twiddle with the
508 SCM properties = Font_interface::text_font_alist_chain (me);
510 Direction stem_dir = stems.size () ? to_dir (stems[0]->get_property ("direction")) : UP;
512 Stencil score = *unsmob_stencil (Text_interface::interpret_markup
513 (me->layout ()->self_scm (), properties, quant_score));
515 if (!score.is_empty ())
516 the_beam.add_at_edge (Y_AXIS, stem_dir, score, 1.0, 0);
520 return the_beam.smobbed_copy ();
524 Beam::get_default_dir (Grob *me)
526 Drul_array<int> total;
527 total[UP] = total[DOWN] = 0;
528 Drul_array<int> count;
529 count[UP] = count[DOWN] = 0;
531 extract_grob_set (me, "stems", stems);
533 for (int i = 0; i < stems.size (); i++)
536 Direction stem_dir = CENTER;
537 SCM stem_dir_scm = s->get_property_data (ly_symbol2scm ("direction"));
538 if (is_direction (stem_dir_scm))
539 stem_dir = to_dir (stem_dir_scm);
541 stem_dir = Stem::get_default_dir (s);
546 total[stem_dir] += max (int (- stem_dir * Stem::head_positions (s) [-stem_dir]), 0);
550 Direction dir = CENTER;
552 if (Direction d = (Direction) sign (count[UP] - count[DOWN]))
554 else if (Direction d = (Direction) sign (total[UP] / count[UP] - total[DOWN]/count[DOWN]))
556 else if (Direction d = (Direction) sign (total[UP] - total[DOWN]))
559 dir = to_dir (me->get_property ("neutral-direction"));
564 /* Set all stems with non-forced direction to beam direction.
565 Urg: non-forced should become `without/with unforced' direction,
566 once stem gets cleaned-up. */
568 Beam::set_stem_directions (Grob *me, Direction d)
570 extract_grob_set (me, "stems", stems);
572 for (int i = 0; i < stems.size (); i++)
576 SCM forcedir = s->get_property_data (ly_symbol2scm ("direction"));
577 if (!to_dir (forcedir))
578 set_grob_direction (s, d);
583 Only try horizontal beams for knees. No reliable detection of
584 anything else is possible here, since we don't know funky-beaming
585 settings, or X-distances (slopes!) People that want sloped
586 knee-beams, should set the directions manually.
591 this routine should take into account the stemlength scoring
592 of a possible knee/nonknee beam.
595 Beam::consider_auto_knees (Grob *me)
597 SCM scm = me->get_property ("auto-knee-gap");
598 if (!scm_is_number (scm))
605 extract_grob_set (me, "stems", stems);
607 Grob *common = common_refpoint_of_array (stems, me, Y_AXIS);
608 Real staff_space = Staff_symbol_referencer::staff_space (me);
610 Array<Interval> head_extents_array;
611 for (int i = 0; i < stems.size (); i++)
613 Grob *stem = stems[i];
614 if (Stem::is_invisible (stem))
617 Interval head_extents = Stem::head_positions (stem);
618 if (!head_extents.is_empty ())
620 head_extents[LEFT] += -1;
621 head_extents[RIGHT] += 1;
622 head_extents *= staff_space * 0.5;
625 We could subtract beam Y position, but this routine only
626 sets stem directions, a constant shift does not have an
629 head_extents += stem->relative_coordinate (common, Y_AXIS);
631 if (to_dir (stem->get_property_data (ly_symbol2scm ("direction"))))
633 Direction stemdir = to_dir (stem->get_property ("direction"));
634 head_extents[-stemdir] = -stemdir * infinity_f;
637 head_extents_array.push (head_extents);
639 gaps.remove_interval (head_extents);
643 Real max_gap_len = 0.0;
645 for (int i = gaps.allowed_regions_.size () -1; i >= 0; i--)
647 Interval gap = gaps.allowed_regions_[i];
650 the outer gaps are not knees.
652 if (isinf (gap[LEFT]) || isinf (gap[RIGHT]))
655 if (gap.length () >= max_gap_len)
657 max_gap_len = gap.length ();
662 Real beam_translation = get_beam_translation (me);
663 Real beam_thickness = Beam::get_thickness (me);
664 int beam_count = Beam::get_beam_count (me);
665 Real height_of_beams = beam_thickness / 2
666 + (beam_count - 1) * beam_translation;
667 Real threshold = scm_to_double (scm) + height_of_beams;
669 if (max_gap_len > threshold)
672 for (int i = 0; i < stems.size (); i++)
674 Grob *stem = stems[i];
675 if (Stem::is_invisible (stem))
678 Interval head_extents = head_extents_array[j++];
680 Direction d = (head_extents.center () < max_gap.center ())
683 stem->set_property ("direction", scm_from_int (d));
685 head_extents.intersect (max_gap);
686 assert (head_extents.is_empty () || head_extents.length () < 1e-6);
691 /* Set stem's shorten property if unset.
694 take some y-position (chord/beam/nearest?) into account
695 scmify forced-fraction
697 This is done in beam because the shorten has to be uniform over the
704 set_minimum_dy (Grob *me, Real *dy)
709 If dy is smaller than the smallest quant, we
710 get absurd direction-sign penalties.
713 Real ss = Staff_symbol_referencer::staff_space (me);
714 Real thickness = Beam::get_thickness (me) / ss;
715 Real slt = Staff_symbol_referencer::line_thickness (me) / ss;
716 Real sit = (thickness - slt) / 2;
718 Real hang = 1.0 - (thickness - slt) / 2;
720 *dy = sign (*dy) * max (fabs (*dy),
721 min (min (sit, inter), hang));
727 MAKE_SCHEME_CALLBACK(Beam, calc_stem_shorten, 1)
729 Beam::calc_stem_shorten (SCM smob)
731 Grob *me = unsmob_grob (smob);
734 shortening looks silly for x staff beams
737 return scm_from_int (0);
739 Real forced_fraction = 1.0 * forced_stem_count (me)
740 / visible_stem_count (me);
742 int beam_count = get_beam_count (me);
744 SCM shorten_list = me->get_property ("beamed-stem-shorten");
745 if (shorten_list == SCM_EOL)
746 return scm_from_int (0);
748 Real staff_space = Staff_symbol_referencer::staff_space (me);
751 = robust_list_ref (beam_count -1, shorten_list);
752 Real shorten = scm_to_double (shorten_elt) * staff_space;
754 shorten *= forced_fraction;
758 return scm_from_double (shorten);
760 return scm_from_double (0.0);
766 Compute a first approximation to the beam slope.
768 MAKE_SCHEME_CALLBACK (Beam, calc_least_squares_positions, 2);
770 Beam::calc_least_squares_positions (SCM smob, SCM posns)
774 Grob *me = unsmob_grob (smob);
776 int count = visible_stem_count (me);
779 return ly_interval2scm (pos);
782 extract_grob_set (me, "stems", stems);
783 Grob *commonx = common_refpoint_of_array (stems, me, X_AXIS);
784 Grob *commony = common_refpoint_of_array (stems, me, Y_AXIS);
786 Real my_y = me->relative_coordinate (commony, Y_AXIS);
788 Grob *fvs = first_visible_stem (me);
789 Grob *lvs = last_visible_stem (me);
791 Interval ideal (Stem::get_stem_info (fvs).ideal_y_
792 + fvs->relative_coordinate (commony, Y_AXIS) -my_y,
793 Stem::get_stem_info (lvs).ideal_y_
794 + lvs->relative_coordinate (commony, Y_AXIS) - my_y);
796 Real x0 = first_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
797 for (int i = 0; i < stems.size (); i++)
801 Real x = s->relative_coordinate (commonx, X_AXIS) - x0;
804 Real dx = last_visible_stem (me)->relative_coordinate (commonx, X_AXIS) - x0;
812 Interval chord (Stem::chord_start_y (first_visible_stem (me)),
813 Stem::chord_start_y (last_visible_stem (me)));
815 /* Simple beams (2 stems) on middle line should be allowed to be
818 However, if both stems reach middle line,
819 ideal[LEFT] == ideal[RIGHT] and ideal.delta () == 0.
821 For that case, we apply artificial slope */
822 if (!ideal[LEFT] && chord.delta () && count == 2)
825 Direction d = (Direction) (sign (chord.delta ()) * UP);
826 pos[d] = get_thickness (me) / 2;
833 For broken beams this doesn't work well. In this case, the
834 slope esp. of the first part of a broken beam should predict
835 where the second part goes.
837 ldy = pos[RIGHT] - pos[LEFT];
841 Array<Offset> ideals;
842 for (int i = 0; i < stems.size (); i++)
845 if (Stem::is_invisible (s))
847 ideals.push (Offset (x_posns[i],
848 Stem::get_stem_info (s).ideal_y_
849 + s->relative_coordinate (commony, Y_AXIS)
853 minimise_least_squares (&slope, &y, ideals);
857 set_minimum_dy (me, &dy);
860 pos = Interval (y, (y + dy));
864 "position" is relative to the staff.
866 scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
868 me->set_property ("least-squares-dy", scm_from_double (ldy));
869 return ly_interval2scm (pos);
873 We can't combine with previous function, since check concave and
874 slope damping comes first.
876 TODO: we should use the concaveness to control the amount of damping
879 MAKE_SCHEME_CALLBACK (Beam, shift_region_to_valid, 2);
881 Beam::shift_region_to_valid (SCM grob, SCM posns)
883 Grob *me = unsmob_grob (grob);
888 extract_grob_set (me, "stems", stems);
889 Grob *commonx = common_refpoint_of_array (stems, me, X_AXIS);
890 Grob *commony = common_refpoint_of_array (stems, me, Y_AXIS);
892 Grob *fvs = first_visible_stem (me);
897 Real x0 = fvs->relative_coordinate (commonx, X_AXIS);
898 for (int i = 0; i < stems.size (); i++)
902 Real x = s->relative_coordinate (commonx, X_AXIS) - x0;
906 Grob *lvs = last_visible_stem (me);
910 Real dx = lvs->relative_coordinate (commonx, X_AXIS) - x0;
912 Drul_array<Real> pos = ly_scm2interval (posns);
915 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
917 Real dy = pos[RIGHT] - pos[LEFT];
919 Real slope = dx ? (dy / dx) : 0.0;
922 Shift the positions so that we have a chance of finding good
923 quants (i.e. no short stem failures.)
925 Interval feasible_left_point;
926 feasible_left_point.set_full ();
927 for (int i = 0; i < stems.size (); i++)
930 if (Stem::is_invisible (s))
933 Direction d = get_grob_direction (s);
936 = Stem::get_stem_info (s).shortest_y_
937 - slope * x_posns [i];
940 left_y is now relative to the stem S. We want relative to
941 ourselves, so translate:
944 += + s->relative_coordinate (commony, Y_AXIS)
945 - me->relative_coordinate (commony, Y_AXIS);
951 feasible_left_point.intersect (flp);
954 if (feasible_left_point.is_empty ())
955 warning (_ ("no viable initial configuration found: may not find good beam slope"));
956 else if (!feasible_left_point.contains (y))
958 const int REGION_SIZE = 2; // UGH UGH
959 if (isinf (feasible_left_point[DOWN]))
960 y = feasible_left_point[UP] - REGION_SIZE;
961 else if (isinf (feasible_left_point[UP]))
962 y = feasible_left_point[DOWN]+ REGION_SIZE;
964 y = feasible_left_point.center ();
967 pos = Drul_array<Real> (y, (y + dy));
968 scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
970 return ly_interval2scm (pos);
973 /* This neat trick is by Werner Lemberg,
974 damped = tanh (slope)
975 corresponds with some tables in [Wanske] CHECKME */
976 MAKE_SCHEME_CALLBACK (Beam, slope_damping, 2);
978 Beam::slope_damping (SCM smob, SCM posns)
980 Grob *me = unsmob_grob (smob);
981 Drul_array<Real> pos = ly_scm2interval (posns);
983 if (visible_stem_count (me) <= 1)
987 SCM s = me->get_property ("damping");
988 Real damping = scm_to_double (s);
989 Real concaveness = robust_scm2double (me->get_property ("concaveness"), 0.0);
990 if (concaveness >= 10000)
992 pos[LEFT] = pos[RIGHT];
993 me->set_property ("least-squares-dy", scm_from_double (0));
999 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
1001 Real dy = pos[RIGHT] - pos[LEFT];
1003 Grob *fvs = first_visible_stem (me);
1004 Grob *lvs = last_visible_stem (me);
1006 Grob *commonx = fvs->common_refpoint (lvs, X_AXIS);
1008 Real dx = last_visible_stem (me)->relative_coordinate (commonx, X_AXIS)
1009 - first_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
1011 Real slope = dy && dx ? dy / dx : 0;
1013 slope = 0.6 * tanh (slope) / (damping + concaveness);
1015 Real damped_dy = slope * dx;
1017 set_minimum_dy (me, &damped_dy);
1019 pos[LEFT] += (dy - damped_dy) / 2;
1020 pos[RIGHT] -= (dy - damped_dy) / 2;
1022 scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
1025 return ly_interval2scm (pos);
1029 Report slice containing the numbers that are both in (car BEAMING)
1033 where_are_the_whole_beams (SCM beaming)
1037 for (SCM s = scm_car (beaming); scm_is_pair (s); s = scm_cdr (s))
1039 if (scm_c_memq (scm_car (s), scm_cdr (beaming)) != SCM_BOOL_F)
1041 l.add_point (scm_to_int (scm_car (s)));
1047 /* Return the Y position of the stem-end, given the Y-left, Y-right
1048 in POS for stem S. This Y position is relative to S. */
1050 Beam::calc_stem_y (Grob *me, Grob *s, Grob ** common,
1052 Drul_array<Real> pos, bool french)
1054 Real beam_translation = get_beam_translation (me);
1056 Real r = s->relative_coordinate (common[X_AXIS], X_AXIS) - xl;
1057 Real dy = pos[RIGHT] - pos[LEFT];
1059 Real stem_y_beam0 = (dy && dx
1064 Direction my_dir = get_grob_direction (s);
1065 SCM beaming = s->get_property ("beaming");
1067 Real stem_y = stem_y_beam0;
1070 Slice bm = where_are_the_whole_beams (beaming);
1071 if (!bm.is_empty ())
1072 stem_y += beam_translation * bm[-my_dir];
1076 Slice bm = Stem::beam_multiplicity (s);
1077 if (!bm.is_empty ())
1078 stem_y += bm[my_dir] * beam_translation;
1081 Real id = me->relative_coordinate (common[Y_AXIS], Y_AXIS)
1082 - s->relative_coordinate (common[Y_AXIS], Y_AXIS);
1088 Hmm. At this time, beam position and slope are determined. Maybe,
1089 stem directions and length should set to relative to the chord's
1090 position of the beam. */
1091 MAKE_SCHEME_CALLBACK(Beam, set_stem_lengths, 1);
1093 Beam::set_stem_lengths (SCM smob)
1095 Grob *me = unsmob_grob (smob);
1097 /* trigger callback. */
1098 (void) me->get_property ("direction");
1100 SCM posns = me->get_property ("positions");
1102 extract_grob_set (me, "stems", stems);
1107 for (int a = 2; a--;)
1108 common[a] = common_refpoint_of_array (stems, me, Axis (a));
1110 Drul_array<Real> pos = ly_scm2realdrul (posns);
1111 Real staff_space = Staff_symbol_referencer::staff_space (me);
1112 scale_drul (&pos, staff_space);
1116 if (scm_is_number (me->get_property ("gap-count"))
1117 && scm_to_int (me->get_property ("gap-count")))
1120 thick = get_thickness (me);
1123 Grob *fvs = first_visible_stem (me);
1124 Grob *lvs = last_visible_stem (me);
1126 Real xl = fvs ? fvs->relative_coordinate (common[X_AXIS], X_AXIS) : 0.0;
1127 Real xr = lvs ? lvs->relative_coordinate (common[X_AXIS], X_AXIS) : 0.0;
1129 for (int i = 0; i < stems.size (); i++)
1132 if (Stem::is_invisible (s))
1135 bool french = to_boolean (s->get_property ("french-beaming"));
1136 Real stem_y = calc_stem_y (me, s, common,
1138 pos, french && s != lvs && s!= fvs);
1141 Make the stems go up to the end of the beam. This doesn't matter
1142 for normal beams, but for tremolo beams it looks silly otherwise.
1145 stem_y += thick * 0.5 * get_grob_direction (s);
1147 Stem::set_stemend (s, 2 * stem_y / staff_space);
1154 Beam::set_beaming (Grob *me, Beaming_info_list const *beaming)
1156 extract_grob_set (me, "stems", stems);
1159 for (int i = 0; i < stems.size (); i++)
1162 Don't overwrite user settings.
1166 Grob *stem = stems[i];
1167 SCM beaming_prop = stem->get_property ("beaming");
1168 if (beaming_prop == SCM_EOL
1169 || index_get_cell (beaming_prop, d) == SCM_EOL)
1171 int b = beaming->infos_.elem (i).beams_i_drul_[d];
1173 && i < stems.size () -1
1174 && Stem::is_invisible (stem))
1175 b = min (b, beaming->infos_.elem (i).beams_i_drul_[-d]);
1177 Stem::set_beaming (stem, b, d);
1180 while (flip (&d) != LEFT);
1185 Beam::forced_stem_count (Grob *me)
1187 extract_grob_set (me, "stems", stems);
1190 for (int i = 0; i < stems.size (); i++)
1194 if (Stem::is_invisible (s))
1197 /* I can imagine counting those boundaries as a half forced stem,
1198 but let's count them full for now. */
1199 if (abs (Stem::chord_start_y (s)) > 0.1
1200 && (get_grob_direction (s) != Stem::get_default_dir (s)))
1207 Beam::visible_stem_count (Grob *me)
1209 extract_grob_set (me, "stems", stems);
1211 for (int i = stems.size (); i--;)
1213 if (!Stem::is_invisible (stems[i]))
1220 Beam::first_visible_stem (Grob *me)
1222 extract_grob_set (me, "stems", stems);
1224 for (int i = 0; i < stems.size (); i++)
1226 if (!Stem::is_invisible (stems[i]))
1233 Beam::last_visible_stem (Grob *me)
1235 extract_grob_set (me, "stems", stems);
1237 for (int i = stems.size (); i--;)
1239 if (!Stem::is_invisible (stems[i]))
1248 handle rest under beam (do_post: beams are calculated now)
1249 what about combination of collisions and rest under beam.
1253 rest -> stem -> beam -> interpolate_y_position ()
1255 MAKE_SCHEME_CALLBACK (Beam, rest_collision_callback, 2);
1257 Beam::rest_collision_callback (SCM smob, SCM prev_offset)
1259 Grob *rest = unsmob_grob (smob);
1260 if (scm_is_number (rest->get_property ("staff-position")))
1261 return scm_from_int (0);
1263 Real offset = robust_scm2double (prev_offset, 0.0);
1265 Grob *st = unsmob_grob (rest->get_object ("stem"));
1268 return scm_from_double (0.0);
1269 Grob *beam = unsmob_grob (stem->get_object ("beam"));
1271 || !Beam::has_interface (beam)
1272 || !Beam::visible_stem_count (beam))
1273 return scm_from_double (0.0);
1275 Drul_array<Real> pos (0, 0);
1276 SCM s = beam->get_property ("positions");
1277 if (scm_is_pair (s) && scm_is_number (scm_car (s)))
1278 pos = ly_scm2interval (s);
1280 programming_error ("positions property should always be pair of numbers.");
1282 Real staff_space = Staff_symbol_referencer::staff_space (rest);
1284 scale_drul (&pos, staff_space);
1286 Real dy = pos[RIGHT] - pos[LEFT];
1288 Drul_array<Grob*> visible_stems (first_visible_stem (beam),
1289 last_visible_stem (beam));
1291 Grob *common = visible_stems[RIGHT]
1292 ->common_refpoint (visible_stems[LEFT], X_AXIS);
1294 Real x0 = visible_stems[LEFT]->relative_coordinate (common, X_AXIS);
1295 Real dx = visible_stems[RIGHT]->relative_coordinate (common, X_AXIS) - x0;
1296 Real slope = dy && dx ? dy / dx : 0;
1298 Direction d = get_grob_direction (stem);
1299 Real stem_y = pos[LEFT]
1300 + (stem->relative_coordinate (common, X_AXIS) - x0) * slope;
1302 Real beam_translation = get_beam_translation (beam);
1303 Real beam_thickness = Beam::get_thickness (beam);
1306 TODO: this is not strictly correct for 16th knee beams.
1309 = Stem::beam_multiplicity (stem).length () + 1;
1311 Real height_of_my_beams = beam_thickness / 2
1312 + (beam_count - 1) * beam_translation;
1313 Real beam_y = stem_y - d * height_of_my_beams;
1315 Grob *common_y = rest->common_refpoint (beam, Y_AXIS);
1316 Interval rest_extent = rest->extent (common_y, Y_AXIS);
1317 rest_extent.translate (offset);
1319 Real rest_dim = rest_extent[d];
1320 Real minimum_distance
1321 = staff_space * (robust_scm2double (stem->get_property ("stemlet-length"), 0.0)
1322 + robust_scm2double (rest->get_property ("minimum-distance"), 0.0));
1324 Real shift = d * min (((beam_y - d * minimum_distance) - rest_dim) * d, 0.0);
1326 shift /= staff_space;
1327 Real rad = Staff_symbol_referencer::line_count (rest) * staff_space / 2;
1329 /* Always move discretely by half spaces */
1330 shift = ceil (fabs (shift * 2.0)) / 2.0 * sign (shift);
1332 /* Inside staff, move by whole spaces*/
1333 if ((rest_extent[d] + staff_space * shift) * d
1335 || (rest_extent[-d] + staff_space * shift) * -d
1337 shift = ceil (fabs (shift)) * sign (shift);
1339 return scm_from_double (staff_space * shift);
1343 Beam::is_knee (Grob *me)
1345 SCM k = me->get_property ("knee");
1346 if (scm_is_bool (k))
1347 return ly_scm2bool (k);
1351 extract_grob_set (me, "stems", stems);
1352 for (int i = stems.size (); i--;)
1354 Direction dir = get_grob_direction (stems[i]);
1363 me->set_property ("knee", ly_bool2scm (knee));
1369 Beam::get_direction_beam_count (Grob *me, Direction d)
1371 extract_grob_set (me, "stems", stems);
1374 for (int i = stems.size (); i--;)
1377 Should we take invisible stems into account?
1379 if (get_grob_direction (stems[i]) == d)
1380 bc = max (bc, (Stem::beam_multiplicity (stems[i]).length () + 1));
1386 ADD_INTERFACE (Beam,
1390 "The @code{thickness} property is the weight of beams, "
1391 "measured in staffspace. The @code{direction} "
1392 "property is not user-serviceable. Use "
1393 "the @code{direction} property of @code{Stem} instead. "
1399 "beamed-stem-shorten "
1413 "neutral-direction "
1416 "quantized-positions "