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);
164 set_stem_shorten (me);
167 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)
213 Beam::connect_beams (Grob *me)
215 extract_grob_set (me, "stems", stems);
218 last_int.set_empty ();
220 SCM last_beaming = scm_cons (SCM_EOL, scm_list_1 (scm_from_int (0)));
221 Direction last_dir = CENTER;
222 for (int i = 0; i < stems.size (); i++)
224 Grob *this_stem = stems[i];
225 SCM this_beaming = this_stem->get_property ("beaming");
227 Direction this_dir = get_grob_direction (this_stem);
228 if (scm_is_pair (last_beaming) && scm_is_pair (this_beaming))
230 int start_point = position_with_maximal_common_beams
231 (last_beaming, this_beaming,
232 last_dir ? last_dir : this_dir,
239 new_slice.set_empty ();
240 SCM s = index_get_cell (this_beaming, d);
241 for (; scm_is_pair (s); s = scm_cdr (s))
244 = start_point - this_dir * scm_to_int (scm_car (s));
246 new_slice.add_point (new_beam_pos);
247 scm_set_car_x (s, scm_from_int (new_beam_pos));
250 while (flip (&d) != LEFT);
252 if (!new_slice.is_empty ())
253 last_int = new_slice;
257 SCM s = scm_cdr (this_beaming);
258 for (; scm_is_pair (s); s = scm_cdr (s))
260 int np = -this_dir * scm_to_int (scm_car (s));
261 scm_set_car_x (s, scm_from_int (np));
262 last_int.add_point (np);
266 if (scm_ilength (scm_cdr (this_beaming)) > 0)
268 last_beaming = this_beaming;
275 I really enjoy spaghetti, but spaghetti should be kept on a plate
276 with a little garlic and olive oil. This is too much.
280 MAKE_SCHEME_CALLBACK (Beam, print, 1);
282 Beam::print (SCM grob)
284 Spanner *me = unsmob_spanner (grob);
286 extract_grob_set (me, "stems", stems);
287 Grob *xcommon = common_refpoint_of_array (stems, me, X_AXIS);
289 xcommon = me->get_bound (LEFT)->common_refpoint (xcommon, X_AXIS);
290 xcommon = me->get_bound (RIGHT)->common_refpoint (xcommon, X_AXIS);
293 if (visible_stem_count (me))
295 // ugh -> use commonx
296 x0 = first_visible_stem (me)->relative_coordinate (xcommon, X_AXIS);
297 dx = last_visible_stem (me)->relative_coordinate (xcommon, X_AXIS) - x0;
301 x0 = stems[0]->relative_coordinate (xcommon, X_AXIS);
302 dx = stems.top ()->relative_coordinate (xcommon, X_AXIS) - x0;
305 SCM posns = me->get_property ("quantized-positions");
306 Drul_array<Real> pos;
307 if (!is_number_pair (posns))
309 programming_error ("no beam positions?");
310 pos = Interval (0, 0);
313 pos = ly_scm2realdrul (posns);
315 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
317 Real dy = pos[RIGHT] - pos[LEFT];
318 Real slope = (dy && dx) ? dy / dx : 0;
320 Real thick = get_thickness (me);
321 Real bdy = get_beam_translation (me);
323 SCM last_beaming = SCM_EOL;
324 Real last_xposn = -1;
325 Real last_stem_width = -1;
327 Real gap_length = robust_scm2double (me->get_property ("gap"), 0.0);
330 Real lt = me->layout ()->get_dimension (ly_symbol2scm ("linethickness"));
332 for (int i = 0; i <= stems.size (); i++)
334 Grob *stem = (i < stems.size ()) ? stems[i] : 0;
336 SCM this_beaming = stem ? stem->get_property ("beaming") : SCM_EOL;
337 Real xposn = stem ? stem->relative_coordinate (xcommon, X_AXIS) : 0.0;
338 Real stem_width = stem ? robust_scm2double (stem->get_property ("thickness"), 1.0) * lt : 0;
339 Direction stem_dir = stem ? to_dir (stem->get_property ("direction")) : CENTER;
341 We do the space left of ST, with lfliebertjes pointing to the
342 right from the left stem, and rfliebertjes pointing left from
345 SCM left = (i > 0) ? scm_cdr (last_beaming) : SCM_EOL;
346 SCM right = stem ? scm_car (this_beaming) : SCM_EOL;
348 Array<int> full_beams;
349 Array<int> lfliebertjes;
350 Array<int> rfliebertjes;
353 scm_is_pair (s); s = scm_cdr (s))
355 int b = scm_to_int (scm_car (s));
356 if (scm_c_memq (scm_car (s), right) != SCM_BOOL_F)
359 lfliebertjes.push (b);
362 scm_is_pair (s); s = scm_cdr (s))
364 int b = scm_to_int (scm_car (s));
365 if (scm_c_memq (scm_car (s), left) == SCM_BOOL_F)
366 rfliebertjes.push (b);
369 Drul_array<Real> break_overshoot
370 = robust_scm2drul (me->get_property ("break-overshoot"),
371 Drul_array<Real> (-0.5, 0.0));
373 Real w = (i > 0 && stem)
374 ? (xposn - last_xposn)
375 : break_overshoot[ (i == 0) ? LEFT : RIGHT];
377 Real stem_offset = 0.0;
380 w += last_stem_width / 2;
381 stem_offset = -last_stem_width / 2;
387 Real blot = me->layout ()->get_dimension (ly_symbol2scm ("blotdiameter"));
388 Stencil whole = Lookup::beam (slope, w, thick, blot);
392 if (scm_is_number (me->get_property ("gap-count")))
394 gap_count = scm_to_int (me->get_property ("gap-count"));
395 gapped = Lookup::beam (slope, w - 2 * gap_length, thick, blot);
397 full_beams.sort (default_compare);
399 full_beams.reverse ();
403 for (int j = full_beams.size (); j--;)
410 b.translate_axis (gap_length, X_AXIS);
412 b.translate_axis (last_xposn - x0 + stem_offset, X_AXIS);
413 b.translate_axis (slope * (last_xposn - x0) + bdy * full_beams[j], Y_AXIS);
415 the_beam.add_stencil (b);
418 if (lfliebertjes.size () || rfliebertjes.size ())
424 int t = Stem::duration_log (stem);
432 nw_f = break_overshoot[RIGHT] / 2;
434 /* Half beam should be one note-width,
435 but let's make sure two half-beams never touch */
439 rw = min (nw_f, ((xposn - last_xposn) / 2));
442 if (me->get_bound (LEFT)->break_status_dir ())
443 rw = xposn - me->get_bound (LEFT)->extent (xcommon, X_AXIS)[RIGHT]
444 + break_overshoot[LEFT];
450 lw = min (nw_f, ((xposn - last_xposn) / 2));
453 lw = me->get_bound (RIGHT)->relative_coordinate (xcommon, X_AXIS)
455 + break_overshoot[RIGHT];
457 rw += stem_width / 2;
458 lw += last_stem_width / 2;
460 Stencil rhalf = Lookup::beam (slope, rw, thick, blot);
461 Stencil lhalf = Lookup::beam (slope, lw, thick, blot);
462 for (int j = lfliebertjes.size (); j--;)
465 b.translate_axis (last_xposn - x0 - last_stem_width /2,
467 b.translate_axis (slope * (last_xposn - x0)
468 + bdy * lfliebertjes[j],
470 the_beam.add_stencil (b);
472 for (int j = rfliebertjes.size (); j--;)
475 b.translate_axis (xposn - x0 - rw + stem_width / 2, X_AXIS);
476 b.translate_axis (slope * (xposn - x0 - rw)
477 + bdy * rfliebertjes[j], Y_AXIS);
478 the_beam.add_stencil (b);
483 last_stem_width = stem_width;
484 last_beaming = this_beaming;
487 the_beam.translate_axis (x0 - me->relative_coordinate (xcommon, X_AXIS),
489 the_beam.translate_axis (pos[LEFT], Y_AXIS);
492 SCM quant_score = me->get_property ("quant-score");
493 SCM debug = me->layout ()->lookup_variable (ly_symbol2scm ("debug-beam-quanting"));
494 if (to_boolean (debug) && scm_is_string (quant_score))
498 This code prints the demerits for each beam. Perhaps this
499 should be switchable for those who want to twiddle with the
503 SCM properties = Font_interface::text_font_alist_chain (me);
505 Direction stem_dir = stems.size () ? to_dir (stems[0]->get_property ("direction")) : UP;
507 Stencil score = *unsmob_stencil (Text_interface::interpret_markup
508 (me->layout ()->self_scm (), properties, quant_score));
510 if (!score.is_empty ())
511 the_beam.add_at_edge (Y_AXIS, stem_dir, score, 1.0, 0);
515 return the_beam.smobbed_copy ();
519 Beam::get_default_dir (Grob *me)
521 Drul_array<int> total;
522 total[UP] = total[DOWN] = 0;
523 Drul_array<int> count;
524 count[UP] = count[DOWN] = 0;
526 extract_grob_set (me, "stems", stems);
528 for (int i = 0; i < stems.size (); i++)
531 Direction stem_dir = CENTER;
532 SCM stem_dir_scm = s->get_property_data (ly_symbol2scm ("direction"));
533 if (is_direction (stem_dir_scm))
534 stem_dir = to_dir (stem_dir_scm);
536 stem_dir = Stem::get_default_dir (s);
541 total[stem_dir] += max (int (- stem_dir * Stem::head_positions (s) [-stem_dir]), 0);
545 Direction dir = CENTER;
547 if (Direction d = (Direction) sign (count[UP] - count[DOWN]))
549 else if (Direction d = (Direction) sign (total[UP] / count[UP] - total[DOWN]/count[DOWN]))
551 else if (Direction d = (Direction) sign (total[UP] - total[DOWN]))
554 dir = to_dir (me->get_property ("neutral-direction"));
559 /* Set all stems with non-forced direction to beam direction.
560 Urg: non-forced should become `without/with unforced' direction,
561 once stem gets cleaned-up. */
563 Beam::set_stem_directions (Grob *me, Direction d)
565 extract_grob_set (me, "stems", stems);
567 for (int i = 0; i < stems.size (); i++)
571 SCM forcedir = s->get_property_data (ly_symbol2scm ("direction"));
572 if (!to_dir (forcedir))
573 set_grob_direction (s, d);
578 Only try horizontal beams for knees. No reliable detection of
579 anything else is possible here, since we don't know funky-beaming
580 settings, or X-distances (slopes!) People that want sloped
581 knee-beams, should set the directions manually.
586 this routine should take into account the stemlength scoring
587 of a possible knee/nonknee beam.
590 Beam::consider_auto_knees (Grob *me)
592 SCM scm = me->get_property ("auto-knee-gap");
593 if (!scm_is_number (scm))
600 extract_grob_set (me, "stems", stems);
602 Grob *common = common_refpoint_of_array (stems, me, Y_AXIS);
603 Real staff_space = Staff_symbol_referencer::staff_space (me);
605 Array<Interval> head_extents_array;
606 for (int i = 0; i < stems.size (); i++)
608 Grob *stem = stems[i];
609 if (Stem::is_invisible (stem))
612 Interval head_extents = Stem::head_positions (stem);
613 if (!head_extents.is_empty ())
615 head_extents[LEFT] += -1;
616 head_extents[RIGHT] += 1;
617 head_extents *= staff_space * 0.5;
620 We could subtract beam Y position, but this routine only
621 sets stem directions, a constant shift does not have an
624 head_extents += stem->relative_coordinate (common, Y_AXIS);
626 if (to_dir (stem->get_property_data (ly_symbol2scm ("direction"))))
628 Direction stemdir = to_dir (stem->get_property ("direction"));
629 head_extents[-stemdir] = -stemdir * infinity_f;
632 head_extents_array.push (head_extents);
634 gaps.remove_interval (head_extents);
638 Real max_gap_len = 0.0;
640 for (int i = gaps.allowed_regions_.size () -1; i >= 0; i--)
642 Interval gap = gaps.allowed_regions_[i];
645 the outer gaps are not knees.
647 if (isinf (gap[LEFT]) || isinf (gap[RIGHT]))
650 if (gap.length () >= max_gap_len)
652 max_gap_len = gap.length ();
657 Real beam_translation = get_beam_translation (me);
658 Real beam_thickness = Beam::get_thickness (me);
659 int beam_count = Beam::get_beam_count (me);
660 Real height_of_beams = beam_thickness / 2
661 + (beam_count - 1) * beam_translation;
662 Real threshold = scm_to_double (scm) + height_of_beams;
664 if (max_gap_len > threshold)
667 for (int i = 0; i < stems.size (); i++)
669 Grob *stem = stems[i];
670 if (Stem::is_invisible (stem))
673 Interval head_extents = head_extents_array[j++];
675 Direction d = (head_extents.center () < max_gap.center ())
678 stem->set_property ("direction", scm_from_int (d));
680 head_extents.intersect (max_gap);
681 assert (head_extents.is_empty () || head_extents.length () < 1e-6);
686 /* Set stem's shorten property if unset.
689 take some y-position (chord/beam/nearest?) into account
690 scmify forced-fraction
692 This is done in beam because the shorten has to be uniform over the
696 Beam::set_stem_shorten (Grob *me)
699 shortening looks silly for x staff beams
704 Real forced_fraction = 1.0 * forced_stem_count (me)
705 / visible_stem_count (me);
707 int beam_count = get_beam_count (me);
709 SCM shorten_list = me->get_property ("beamed-stem-shorten");
710 if (shorten_list == SCM_EOL)
713 Real staff_space = Staff_symbol_referencer::staff_space (me);
716 = robust_list_ref (beam_count -1, shorten_list);
717 Real shorten = scm_to_double (shorten_elt) * staff_space;
719 shorten *= forced_fraction;
722 me->set_property ("shorten", scm_from_double (shorten));
728 set_minimum_dy (Grob *me, Real *dy)
733 If dy is smaller than the smallest quant, we
734 get absurd direction-sign penalties.
737 Real ss = Staff_symbol_referencer::staff_space (me);
738 Real thickness = Beam::get_thickness (me) / ss;
739 Real slt = Staff_symbol_referencer::line_thickness (me) / ss;
740 Real sit = (thickness - slt) / 2;
742 Real hang = 1.0 - (thickness - slt) / 2;
744 *dy = sign (*dy) * max (fabs (*dy),
745 min (min (sit, inter), hang));
750 Compute a first approximation to the beam slope.
752 MAKE_SCHEME_CALLBACK (Beam, calc_least_squares_positions, 2);
754 Beam::calc_least_squares_positions (SCM smob, SCM posns)
758 Grob *me = unsmob_grob (smob);
760 int count = visible_stem_count (me);
763 return ly_interval2scm (pos);
766 extract_grob_set (me, "stems", stems);
767 Grob *commonx = common_refpoint_of_array (stems, me, X_AXIS);
768 Grob *commony = common_refpoint_of_array (stems, me, Y_AXIS);
770 Real my_y = me->relative_coordinate (commony, Y_AXIS);
772 Grob *fvs = first_visible_stem (me);
773 Grob *lvs = last_visible_stem (me);
775 Interval ideal (Stem::get_stem_info (fvs).ideal_y_
776 + fvs->relative_coordinate (commony, Y_AXIS) -my_y,
777 Stem::get_stem_info (lvs).ideal_y_
778 + lvs->relative_coordinate (commony, Y_AXIS) - my_y);
780 Real x0 = first_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
781 for (int i = 0; i < stems.size (); i++)
785 Real x = s->relative_coordinate (commonx, X_AXIS) - x0;
788 Real dx = last_visible_stem (me)->relative_coordinate (commonx, X_AXIS) - x0;
796 Interval chord (Stem::chord_start_y (first_visible_stem (me)),
797 Stem::chord_start_y (last_visible_stem (me)));
799 /* Simple beams (2 stems) on middle line should be allowed to be
802 However, if both stems reach middle line,
803 ideal[LEFT] == ideal[RIGHT] and ideal.delta () == 0.
805 For that case, we apply artificial slope */
806 if (!ideal[LEFT] && chord.delta () && count == 2)
809 Direction d = (Direction) (sign (chord.delta ()) * UP);
810 pos[d] = get_thickness (me) / 2;
817 For broken beams this doesn't work well. In this case, the
818 slope esp. of the first part of a broken beam should predict
819 where the second part goes.
821 ldy = pos[RIGHT] - pos[LEFT];
825 Array<Offset> ideals;
826 for (int i = 0; i < stems.size (); i++)
829 if (Stem::is_invisible (s))
831 ideals.push (Offset (x_posns[i],
832 Stem::get_stem_info (s).ideal_y_
833 + s->relative_coordinate (commony, Y_AXIS)
837 minimise_least_squares (&slope, &y, ideals);
841 set_minimum_dy (me, &dy);
844 pos = Interval (y, (y + dy));
848 "position" is relative to the staff.
850 scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
852 me->set_property ("least-squares-dy", scm_from_double (ldy));
853 return ly_interval2scm (pos);
857 We can't combine with previous function, since check concave and
858 slope damping comes first.
860 TODO: we should use the concaveness to control the amount of damping
863 MAKE_SCHEME_CALLBACK (Beam, shift_region_to_valid, 2);
865 Beam::shift_region_to_valid (SCM grob, SCM posns)
867 Grob *me = unsmob_grob (grob);
872 extract_grob_set (me, "stems", stems);
873 Grob *commonx = common_refpoint_of_array (stems, me, X_AXIS);
874 Grob *commony = common_refpoint_of_array (stems, me, Y_AXIS);
876 Grob *fvs = first_visible_stem (me);
881 Real x0 = fvs->relative_coordinate (commonx, X_AXIS);
882 for (int i = 0; i < stems.size (); i++)
886 Real x = s->relative_coordinate (commonx, X_AXIS) - x0;
890 Grob *lvs = last_visible_stem (me);
894 Real dx = lvs->relative_coordinate (commonx, X_AXIS) - x0;
896 Drul_array<Real> pos = ly_scm2interval (posns);
899 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
901 Real dy = pos[RIGHT] - pos[LEFT];
903 Real slope = dx ? (dy / dx) : 0.0;
906 Shift the positions so that we have a chance of finding good
907 quants (i.e. no short stem failures.)
909 Interval feasible_left_point;
910 feasible_left_point.set_full ();
911 for (int i = 0; i < stems.size (); i++)
914 if (Stem::is_invisible (s))
917 Direction d = get_grob_direction (s);
920 = Stem::get_stem_info (s).shortest_y_
921 - slope * x_posns [i];
924 left_y is now relative to the stem S. We want relative to
925 ourselves, so translate:
928 += + s->relative_coordinate (commony, Y_AXIS)
929 - me->relative_coordinate (commony, Y_AXIS);
935 feasible_left_point.intersect (flp);
938 if (feasible_left_point.is_empty ())
939 warning (_ ("no viable initial configuration found: may not find good beam slope"));
940 else if (!feasible_left_point.contains (y))
942 const int REGION_SIZE = 2; // UGH UGH
943 if (isinf (feasible_left_point[DOWN]))
944 y = feasible_left_point[UP] - REGION_SIZE;
945 else if (isinf (feasible_left_point[UP]))
946 y = feasible_left_point[DOWN]+ REGION_SIZE;
948 y = feasible_left_point.center ();
951 pos = Drul_array<Real> (y, (y + dy));
952 scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
954 return ly_interval2scm (pos);
957 /* This neat trick is by Werner Lemberg,
958 damped = tanh (slope)
959 corresponds with some tables in [Wanske] CHECKME */
960 MAKE_SCHEME_CALLBACK (Beam, slope_damping, 2);
962 Beam::slope_damping (SCM smob, SCM posns)
964 Grob *me = unsmob_grob (smob);
965 Drul_array<Real> pos = ly_scm2interval (posns);
967 if (visible_stem_count (me) <= 1)
971 SCM s = me->get_property ("damping");
972 Real damping = scm_to_double (s);
973 Real concaveness = robust_scm2double (me->get_property ("concaveness"), 0.0);
974 if (concaveness >= 10000)
976 pos[LEFT] = pos[RIGHT];
977 me->set_property ("least-squares-dy", scm_from_double (0));
983 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
985 Real dy = pos[RIGHT] - pos[LEFT];
987 Grob *fvs = first_visible_stem (me);
988 Grob *lvs = last_visible_stem (me);
990 Grob *commonx = fvs->common_refpoint (lvs, X_AXIS);
992 Real dx = last_visible_stem (me)->relative_coordinate (commonx, X_AXIS)
993 - first_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
995 Real slope = dy && dx ? dy / dx : 0;
997 slope = 0.6 * tanh (slope) / (damping + concaveness);
999 Real damped_dy = slope * dx;
1001 set_minimum_dy (me, &damped_dy);
1003 pos[LEFT] += (dy - damped_dy) / 2;
1004 pos[RIGHT] -= (dy - damped_dy) / 2;
1006 scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
1009 return ly_interval2scm (pos);
1013 Report slice containing the numbers that are both in (car BEAMING)
1017 where_are_the_whole_beams (SCM beaming)
1021 for (SCM s = scm_car (beaming); scm_is_pair (s); s = scm_cdr (s))
1023 if (scm_c_memq (scm_car (s), scm_cdr (beaming)) != SCM_BOOL_F)
1025 l.add_point (scm_to_int (scm_car (s)));
1031 /* Return the Y position of the stem-end, given the Y-left, Y-right
1032 in POS for stem S. This Y position is relative to S. */
1034 Beam::calc_stem_y (Grob *me, Grob *s, Grob ** common,
1036 Drul_array<Real> pos, bool french)
1038 Real beam_translation = get_beam_translation (me);
1040 Real r = s->relative_coordinate (common[X_AXIS], X_AXIS) - xl;
1041 Real dy = pos[RIGHT] - pos[LEFT];
1043 Real stem_y_beam0 = (dy && dx
1048 Direction my_dir = get_grob_direction (s);
1049 SCM beaming = s->get_property ("beaming");
1051 Real stem_y = stem_y_beam0;
1054 Slice bm = where_are_the_whole_beams (beaming);
1055 if (!bm.is_empty ())
1056 stem_y += beam_translation * bm[-my_dir];
1060 Slice bm = Stem::beam_multiplicity (s);
1061 if (!bm.is_empty ())
1062 stem_y += bm[my_dir] * beam_translation;
1065 Real id = me->relative_coordinate (common[Y_AXIS], Y_AXIS)
1066 - s->relative_coordinate (common[Y_AXIS], Y_AXIS);
1072 Hmm. At this time, beam position and slope are determined. Maybe,
1073 stem directions and length should set to relative to the chord's
1074 position of the beam. */
1075 MAKE_SCHEME_CALLBACK(Beam, set_stem_lengths, 1);
1077 Beam::set_stem_lengths (SCM smob)
1079 Grob *me = unsmob_grob (smob);
1081 /* trigger callback. */
1082 (void) me->get_property ("direction");
1084 SCM posns = me->get_property ("positions");
1086 extract_grob_set (me, "stems", stems);
1091 for (int a = 2; a--;)
1092 common[a] = common_refpoint_of_array (stems, me, Axis (a));
1094 Drul_array<Real> pos = ly_scm2realdrul (posns);
1095 Real staff_space = Staff_symbol_referencer::staff_space (me);
1096 scale_drul (&pos, staff_space);
1100 if (scm_is_number (me->get_property ("gap-count"))
1101 && scm_to_int (me->get_property ("gap-count")))
1104 thick = get_thickness (me);
1107 Grob *fvs = first_visible_stem (me);
1108 Grob *lvs = last_visible_stem (me);
1110 Real xl = fvs ? fvs->relative_coordinate (common[X_AXIS], X_AXIS) : 0.0;
1111 Real xr = lvs ? lvs->relative_coordinate (common[X_AXIS], X_AXIS) : 0.0;
1113 for (int i = 0; i < stems.size (); i++)
1116 if (Stem::is_invisible (s))
1119 bool french = to_boolean (s->get_property ("french-beaming"));
1120 Real stem_y = calc_stem_y (me, s, common,
1122 pos, french && s != lvs && s!= fvs);
1125 Make the stems go up to the end of the beam. This doesn't matter
1126 for normal beams, but for tremolo beams it looks silly otherwise.
1129 stem_y += thick * 0.5 * get_grob_direction (s);
1131 Stem::set_stemend (s, 2 * stem_y / staff_space);
1138 Beam::set_beaming (Grob *me, Beaming_info_list const *beaming)
1140 extract_grob_set (me, "stems", stems);
1143 for (int i = 0; i < stems.size (); i++)
1146 Don't overwrite user settings.
1150 Grob *stem = stems[i];
1151 SCM beaming_prop = stem->get_property ("beaming");
1152 if (beaming_prop == SCM_EOL
1153 || index_get_cell (beaming_prop, d) == SCM_EOL)
1155 int b = beaming->infos_.elem (i).beams_i_drul_[d];
1157 && i < stems.size () -1
1158 && Stem::is_invisible (stem))
1159 b = min (b, beaming->infos_.elem (i).beams_i_drul_[-d]);
1161 Stem::set_beaming (stem, b, d);
1164 while (flip (&d) != LEFT);
1169 Beam::forced_stem_count (Grob *me)
1171 extract_grob_set (me, "stems", stems);
1174 for (int i = 0; i < stems.size (); i++)
1178 if (Stem::is_invisible (s))
1181 /* I can imagine counting those boundaries as a half forced stem,
1182 but let's count them full for now. */
1183 if (abs (Stem::chord_start_y (s)) > 0.1
1184 && (get_grob_direction (s) != Stem::get_default_dir (s)))
1191 Beam::visible_stem_count (Grob *me)
1193 extract_grob_set (me, "stems", stems);
1195 for (int i = stems.size (); i--;)
1197 if (!Stem::is_invisible (stems[i]))
1204 Beam::first_visible_stem (Grob *me)
1206 extract_grob_set (me, "stems", stems);
1208 for (int i = 0; i < stems.size (); i++)
1210 if (!Stem::is_invisible (stems[i]))
1217 Beam::last_visible_stem (Grob *me)
1219 extract_grob_set (me, "stems", stems);
1221 for (int i = stems.size (); i--;)
1223 if (!Stem::is_invisible (stems[i]))
1232 handle rest under beam (do_post: beams are calculated now)
1233 what about combination of collisions and rest under beam.
1237 rest -> stem -> beam -> interpolate_y_position ()
1239 MAKE_SCHEME_CALLBACK (Beam, rest_collision_callback, 2);
1241 Beam::rest_collision_callback (SCM smob, SCM prev_offset)
1243 Grob *rest = unsmob_grob (smob);
1244 if (scm_is_number (rest->get_property ("staff-position")))
1245 return scm_from_int (0);
1247 Real offset = robust_scm2double (prev_offset, 0.0);
1249 Grob *st = unsmob_grob (rest->get_object ("stem"));
1252 return scm_from_double (0.0);
1253 Grob *beam = unsmob_grob (stem->get_object ("beam"));
1255 || !Beam::has_interface (beam)
1256 || !Beam::visible_stem_count (beam))
1257 return scm_from_double (0.0);
1259 Drul_array<Real> pos (0, 0);
1260 SCM s = beam->get_property ("positions");
1261 if (scm_is_pair (s) && scm_is_number (scm_car (s)))
1262 pos = ly_scm2interval (s);
1264 programming_error ("positions property should always be pair of numbers.");
1266 Real staff_space = Staff_symbol_referencer::staff_space (rest);
1268 scale_drul (&pos, staff_space);
1270 Real dy = pos[RIGHT] - pos[LEFT];
1272 Drul_array<Grob*> visible_stems (first_visible_stem (beam),
1273 last_visible_stem (beam));
1275 Grob *common = visible_stems[RIGHT]
1276 ->common_refpoint (visible_stems[LEFT], X_AXIS);
1278 Real x0 = visible_stems[LEFT]->relative_coordinate (common, X_AXIS);
1279 Real dx = visible_stems[RIGHT]->relative_coordinate (common, X_AXIS) - x0;
1280 Real slope = dy && dx ? dy / dx : 0;
1282 Direction d = get_grob_direction (stem);
1283 Real stem_y = pos[LEFT]
1284 + (stem->relative_coordinate (common, X_AXIS) - x0) * slope;
1286 Real beam_translation = get_beam_translation (beam);
1287 Real beam_thickness = Beam::get_thickness (beam);
1290 TODO: this is not strictly correct for 16th knee beams.
1293 = Stem::beam_multiplicity (stem).length () + 1;
1295 Real height_of_my_beams = beam_thickness / 2
1296 + (beam_count - 1) * beam_translation;
1297 Real beam_y = stem_y - d * height_of_my_beams;
1299 Grob *common_y = rest->common_refpoint (beam, Y_AXIS);
1300 Interval rest_extent = rest->extent (common_y, Y_AXIS);
1301 rest_extent.translate (offset);
1303 Real rest_dim = rest_extent[d];
1304 Real minimum_distance
1305 = staff_space * (robust_scm2double (stem->get_property ("stemlet-length"), 0.0)
1306 + robust_scm2double (rest->get_property ("minimum-distance"), 0.0));
1308 Real shift = d * min (((beam_y - d * minimum_distance) - rest_dim) * d, 0.0);
1310 shift /= staff_space;
1311 Real rad = Staff_symbol_referencer::line_count (rest) * staff_space / 2;
1313 /* Always move discretely by half spaces */
1314 shift = ceil (fabs (shift * 2.0)) / 2.0 * sign (shift);
1316 /* Inside staff, move by whole spaces*/
1317 if ((rest_extent[d] + staff_space * shift) * d
1319 || (rest_extent[-d] + staff_space * shift) * -d
1321 shift = ceil (fabs (shift)) * sign (shift);
1323 return scm_from_double (staff_space * shift);
1327 Beam::is_knee (Grob *me)
1329 SCM k = me->get_property ("knee");
1330 if (scm_is_bool (k))
1331 return ly_scm2bool (k);
1335 extract_grob_set (me, "stems", stems);
1336 for (int i = stems.size (); i--;)
1338 Direction dir = get_grob_direction (stems[i]);
1347 me->set_property ("knee", ly_bool2scm (knee));
1353 Beam::get_direction_beam_count (Grob *me, Direction d)
1355 extract_grob_set (me, "stems", stems);
1358 for (int i = stems.size (); i--;)
1361 Should we take invisible stems into account?
1363 if (get_grob_direction (stems[i]) == d)
1364 bc = max (bc, (Stem::beam_multiplicity (stems[i]).length () + 1));
1370 ADD_INTERFACE (Beam,
1374 "The @code{thickness} property is the weight of beams, "
1375 "measured in staffspace. The @code{direction} property is not user-serviceable. Use "
1376 "the @code{direction} property of @code{Stem} instead. "
1382 "beamed-stem-shorten "
1395 "neutral-direction "
1398 "quantized-positions "