2 beam.cc -- implement Beam
4 source file of the GNU LilyPond music typesetter
6 (c) 1997--2005 Han-Wen Nienhuys <hanwen@cs.uu.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.
27 #include <math.h> // tanh.
30 #include "interval-set.hh"
31 #include "directional-element-interface.hh"
34 #include "least-squares.hh"
36 #include "output-def.hh"
38 #include "group-interface.hh"
39 #include "staff-symbol-referencer.hh"
45 #include "text-item.hh" // debug output.
46 #include "font-interface.hh" // debug output.
50 Beam::add_stem (Grob *me, Grob *s)
52 Pointer_group_interface::add_grob (me, ly_symbol2scm ("stems"), s);
54 s->add_dependency (me);
56 assert (!Stem::get_beam (s));
57 s->set_property ("beam", me->self_scm ());
59 add_bound_item (dynamic_cast<Spanner *> (me), dynamic_cast<Item *> (s));
63 Beam::get_thickness (Grob *me)
65 return robust_scm2double (me->get_property ("thickness"), 0)
66 * Staff_symbol_referencer::staff_space (me);
69 /* Return the translation between 2 adjoining beams. */
71 Beam::get_beam_translation (Grob *me)
73 SCM func = me->get_property ("space-function");
75 if (ly_c_procedure_p (func))
77 SCM s = scm_call_2 (func, me->self_scm (), scm_int2num (get_beam_count (me)));
78 return scm_to_double (s);
86 /* Maximum beam_count. */
88 Beam::get_beam_count (Grob *me)
91 for (SCM s = me->get_property ("stems"); scm_is_pair (s); s = scm_cdr (s))
93 Grob *stem = unsmob_grob (scm_car (s));
94 m = m >? (Stem::beam_multiplicity (stem).length () + 1);
100 Space return space between beams.
102 MAKE_SCHEME_CALLBACK (Beam, space_function, 2);
104 Beam::space_function (SCM smob, SCM beam_count)
106 Grob *me = unsmob_grob (smob);
108 Real staff_space = Staff_symbol_referencer::staff_space (me);
109 Real line = Staff_symbol_referencer::line_thickness (me);
110 Real thickness = get_thickness (me);
112 Real beam_translation = scm_to_int (beam_count) < 4
113 ? (2*staff_space + line - thickness) / 2.0
114 : (3*staff_space + line - thickness) / 3.0;
116 return scm_make_real (beam_translation);
119 /* After pre-processing all directions should be set.
120 Several post-processing routines (stem, slur, script) need stem/beam
122 Currenly, this means that beam has set all stem's directions.
123 [Alternatively, stems could set its own directions, according to
124 their beam, during 'final-pre-processing'.] */
125 MAKE_SCHEME_CALLBACK (Beam, before_line_breaking, 1);
127 Beam::before_line_breaking (SCM smob)
129 Grob *me = unsmob_grob (smob);
131 /* Beams with less than 2 two stems don't make much sense, but could happen
136 For a beam that only has one stem, we try to do some disappearance magic:
137 we revert the flag, and move on to The Eternal Engraving Fields. */
139 int count = visible_stem_count (me);
142 me->warning (_ ("beam has less than two visible stems"));
144 SCM stems = me->get_property ("stems");
145 if (scm_ilength (stems) == 1)
147 me->warning (_ ("removing beam with less than two stems"));
149 unsmob_grob (scm_car (stems))->set_property ("beam", SCM_EOL);
152 return SCM_UNSPECIFIED;
154 else if (scm_ilength (stems) == 0)
157 return SCM_UNSPECIFIED;
162 Direction d = get_default_dir (me);
164 consider_auto_knees (me);
165 set_stem_directions (me, d);
169 set_stem_shorten (me);
175 /* We want a maximal number of shared beams, but if there is choice, we
176 * take the one that is closest to the end of the stem. This is for
188 position_with_maximal_common_beams (SCM left_beaming, SCM right_beaming,
192 Slice lslice = int_list_to_slice (scm_cdr (left_beaming));
196 for (int i = lslice[-left_dir];
197 (i - lslice[left_dir])* left_dir <= 0; i+= left_dir)
200 for (SCM s = scm_car (right_beaming); scm_is_pair (s); s = scm_cdr (s))
202 int k = -right_dir * scm_to_int (scm_car (s)) + i;
203 if (scm_c_memq (scm_int2num (k), left_beaming) != SCM_BOOL_F)
207 if (count >= best_count)
218 Beam::connect_beams (Grob *me)
220 Link_array<Grob> stems
221 = extract_grob_array (me, ly_symbol2scm ("stems"));
224 last_int.set_empty ();
225 SCM last_beaming = SCM_EOL;
226 Direction last_dir = CENTER;
227 for (int i = 0; i< stems.size (); i++)
229 Grob *this_stem = stems[i];
230 SCM this_beaming = this_stem->get_property ("beaming");
232 Direction this_dir = get_grob_direction (this_stem);
233 if (scm_is_pair (last_beaming) && scm_is_pair (this_beaming))
235 int start_point = position_with_maximal_common_beams
236 (last_beaming, this_beaming,
243 if (d == RIGHT && i == stems.size () - 1)
246 new_slice.set_empty ();
247 SCM s = index_get_cell (this_beaming, d);
248 for (; scm_is_pair (s); s = scm_cdr (s))
251 = start_point - this_dir * scm_to_int (scm_car (s));
253 new_slice.add_point (new_beam_pos);
254 scm_set_car_x (s, scm_int2num (new_beam_pos));
258 while (flip (&d) != LEFT);
260 if (!new_slice.is_empty ())
261 last_int = new_slice;
265 scm_set_car_x (this_beaming, SCM_EOL);
266 SCM s = scm_cdr (this_beaming);
267 for (; scm_is_pair (s); s = scm_cdr (s))
269 int np = -this_dir * scm_to_int (scm_car (s));
270 scm_set_car_x (s, scm_int2num (np));
271 last_int.add_point (np);
275 if (i == stems.size () -1)
277 scm_set_cdr_x (this_beaming, SCM_EOL);
280 if (scm_ilength (scm_cdr (this_beaming)) > 0)
282 last_beaming = this_beaming;
289 TODO: should not make beams per stem, but per Y-level.
291 MAKE_SCHEME_CALLBACK (Beam, print, 1);
293 Beam::print (SCM grob)
295 Spanner *me = unsmob_spanner (grob);
298 Link_array<Grob> stems
299 = extract_grob_array (me, ly_symbol2scm ("stems"));
300 Grob *xcommon = common_refpoint_of_array (stems, me, X_AXIS);
302 xcommon = me->get_bound (LEFT)->common_refpoint (xcommon, X_AXIS);
303 xcommon = me->get_bound (RIGHT)->common_refpoint (xcommon, X_AXIS);
306 if (visible_stem_count (me))
308 // ugh -> use commonx
309 x0 = first_visible_stem (me)->relative_coordinate (xcommon, X_AXIS);
310 dx = last_visible_stem (me)->relative_coordinate (xcommon, X_AXIS) - x0;
314 x0 = stems[0]->relative_coordinate (xcommon, X_AXIS);
315 dx = stems.top ()->relative_coordinate (xcommon, X_AXIS) - x0;
318 SCM posns = me->get_property ("positions");
319 Drul_array<Real> pos;
320 if (!is_number_pair (posns))
322 programming_error ("No beam posns");
323 pos = Interval (0, 0);
326 pos = ly_scm2realdrul (posns);
328 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
330 Real dy = pos[RIGHT] - pos[LEFT];
331 Real slope = (dy && dx) ? dy / dx : 0;
333 Real thick = get_thickness (me);
334 Real bdy = get_beam_translation (me);
336 SCM last_beaming = SCM_EOL;
337 Real last_xposn = -1;
338 Real last_stem_width = -1;
340 Real gap_length = robust_scm2double (me->get_property ("gap"), 0.0);
343 Real lt = me->get_layout ()->get_dimension (ly_symbol2scm ("linethickness"));
345 for (int i = 0; i<= stems.size (); i++)
347 Grob *st = (i < stems.size ()) ? stems[i] : 0;
349 SCM this_beaming = st ? st->get_property ("beaming") : SCM_EOL;
350 Real xposn = st ? st->relative_coordinate (xcommon, X_AXIS) : 0.0;
351 Real stem_width = st ? robust_scm2double (st->get_property ("thickness"), 1.0) *lt : 0;
352 Direction stem_dir = st ? to_dir (st->get_property ("direction")) : CENTER;
354 We do the space left of ST, with lfliebertjes pointing to the
355 right from the left stem, and rfliebertjes pointing left from
358 SCM left = (i > 0) ? scm_cdr (last_beaming) : SCM_EOL;
359 SCM right = st ? scm_car (this_beaming) : SCM_EOL;
361 Array<int> full_beams;
362 Array<int> lfliebertjes;
363 Array<int> rfliebertjes;
366 scm_is_pair (s); s = scm_cdr (s))
368 int b = scm_to_int (scm_car (s));
369 if (scm_c_memq (scm_car (s), right) != SCM_BOOL_F)
375 lfliebertjes.push (b);
379 scm_is_pair (s); s = scm_cdr (s))
381 int b = scm_to_int (scm_car (s));
382 if (scm_c_memq (scm_car (s), left) == SCM_BOOL_F)
384 rfliebertjes.push (b);
389 how much to stick out for beams across linebreaks
391 Real break_overshoot = 3.0;
392 Real w = (i > 0 && st) ? (xposn - last_xposn) : break_overshoot;
394 Real stem_offset = 0.0;
397 w += last_stem_width / 2;
398 stem_offset = -last_stem_width / 2;
404 Real blot = me->get_layout ()->get_dimension (ly_symbol2scm ("blotdiameter"));
405 Stencil whole = Lookup::beam (slope, w, thick, blot);
409 if (scm_is_number (me->get_property ("gap-count")))
411 gap_count = scm_to_int (me->get_property ("gap-count"));
412 gapped = Lookup::beam (slope, w - 2 * gap_length, thick, blot);
414 full_beams.sort (default_compare);
416 full_beams.reverse ();
420 for (int j = full_beams.size (); j--;)
427 b.translate_axis (gap_length, X_AXIS);
429 b.translate_axis (last_xposn - x0 + stem_offset, X_AXIS);
430 b.translate_axis (slope * (last_xposn - x0) + bdy * full_beams[j], Y_AXIS);
432 the_beam.add_stencil (b);
435 if (lfliebertjes.size () || rfliebertjes.size ())
441 int t = Stem::duration_log (st);
443 SCM proc = me->get_property ("flag-width-function");
444 SCM result = scm_call_1 (proc, scm_int2num (t));
445 nw_f = scm_to_double (result);
448 nw_f = break_overshoot / 2;
450 /* Half beam should be one note-width,
451 but let's make sure two half-beams never touch */
455 rw = nw_f <? ((xposn - last_xposn) / 2);
458 TODO: 0.5 is a guess.
460 rw = xposn - me->get_bound (LEFT)->extent (xcommon, X_AXIS)[RIGHT]
464 lw = nw_f <? ((xposn - last_xposn) / 2);
466 lw = me->get_bound (RIGHT)->relative_coordinate (xcommon, X_AXIS)
469 Stencil rhalf = Lookup::beam (slope, rw, thick, blot);
470 Stencil lhalf = Lookup::beam (slope, lw, thick, blot);
471 for (int j = lfliebertjes.size (); j--;)
474 b.translate_axis (last_xposn - x0, X_AXIS);
475 b.translate_axis (slope * (last_xposn - x0) + bdy * lfliebertjes[j], Y_AXIS);
476 the_beam.add_stencil (b);
478 for (int j = rfliebertjes.size (); j--;)
481 b.translate_axis (xposn - x0 - rw, X_AXIS);
482 b.translate_axis (slope * (xposn - x0 -rw) + 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), X_AXIS);
493 the_beam.translate_axis (pos[LEFT], Y_AXIS);
496 SCM quant_score = me->get_property ("quant-score");
497 if (to_boolean (me->get_layout ()->lookup_variable (ly_symbol2scm ("debug-beam-quanting")))
498 && scm_is_string (quant_score))
502 This code prints the demerits for each beam. Perhaps this
503 should be switchable for those who want to twiddle with the
507 SCM properties = Font_interface::text_font_alist_chain (me);
509 Direction stem_dir = stems.size () ? to_dir (stems[0]->get_property ("direction")) : UP;
511 Stencil tm = *unsmob_stencil (Text_interface::interpret_markup
512 (me->get_layout ()->self_scm (), properties, quant_score));
513 the_beam.add_at_edge (Y_AXIS, stem_dir, tm, 1.0, 0);
517 return the_beam.smobbed_copy ();
522 Beam::get_default_dir (Grob *me)
524 Drul_array<int> total;
525 total[UP] = total[DOWN] = 0;
526 Drul_array<int> count;
527 count[UP] = count[DOWN] = 0;
530 Link_array<Grob> stems
531 = extract_grob_array (me, ly_symbol2scm ("stems"));
533 for (int i = 0; i < stems.size (); i++)
537 Direction sd = get_grob_direction (s);
539 int center_distance = int (- d * Stem::head_positions (s) [-d]) >? 0;
540 int current = sd ? (1 + d * sd) / 2 : center_distance;
548 while (flip (&d) != DOWN);
550 SCM func = me->get_property ("dir-function");
551 SCM s = scm_call_2 (func,
552 scm_cons (scm_int2num (count[UP]),
553 scm_int2num (count[DOWN])),
554 scm_cons (scm_int2num (total[UP]),
555 scm_int2num (total[DOWN])));
557 if (scm_is_number (s) && scm_to_int (s))
560 /* If dir is not determined: get default */
561 return 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 Link_array<Grob> stems
571 = extract_grob_array (me, ly_symbol2scm ("stems"));
573 for (int i = 0; i <stems.size (); i++)
577 SCM forcedir = s->get_property ("direction");
578 if (!to_dir (forcedir))
579 set_grob_direction (s, d);
584 Only try horizontal beams for knees. No reliable detection of
585 anything else is possible here, since we don't know funky-beaming
586 settings, or X-distances (slopes!) People that want sloped
587 knee-beams, should set the directions manually.
592 this routine should take into account the stemlength scoring
593 of a possible knee/nonknee beam.
597 Beam::consider_auto_knees (Grob *me)
599 SCM scm = me->get_property ("auto-knee-gap");
600 if (!scm_is_number (scm))
607 Link_array<Grob> stems
608 = extract_grob_array (me, ly_symbol2scm ("stems"));
610 Grob *common = common_refpoint_of_array (stems, me, Y_AXIS);
611 Real staff_space = Staff_symbol_referencer::staff_space (me);
613 Array<Interval> head_extents_array;
614 for (int i = 0; i < stems.size (); i++)
616 Grob *stem = stems[i];
617 if (Stem::is_invisible (stem))
620 Interval head_extents = Stem::head_positions (stem);
621 if (!head_extents.is_empty ())
623 head_extents[LEFT] += -1;
624 head_extents[RIGHT] += 1;
625 head_extents *= staff_space * 0.5;
628 We could subtract beam Y position, but this routine only
629 sets stem directions, a constant shift does not have an
632 head_extents += stem->relative_coordinate (common, Y_AXIS);
634 if (to_dir (stem->get_property ("direction")))
636 Direction stemdir = to_dir (stem->get_property ("direction"));
637 head_extents[-stemdir] = -stemdir * infinity_f;
640 head_extents_array.push (head_extents);
642 gaps.remove_interval (head_extents);
646 Real max_gap_len = 0.0;
648 for (int i = gaps.allowed_regions_.size () -1; i >= 0; i--)
650 Interval gap = gaps.allowed_regions_[i];
653 the outer gaps are not knees.
655 if (isinf (gap[LEFT]) || isinf (gap[RIGHT]))
658 if (gap.length () >= max_gap_len)
660 max_gap_len = gap.length ();
665 Real beam_translation = get_beam_translation (me);
666 Real beam_thickness = Beam::get_thickness (me);
667 int beam_count = Beam::get_beam_count (me);
668 Real height_of_beams = beam_thickness / 2
669 + (beam_count - 1) * beam_translation;
670 Real threshold = scm_to_double (scm) + height_of_beams;
672 if (max_gap_len > threshold)
675 for (int i = 0; i < stems.size (); i++)
677 Grob *stem = stems[i];
678 if (Stem::is_invisible (stem))
681 Interval head_extents = head_extents_array[j++];
683 Direction d = (head_extents.center () < max_gap.center ()) ?
686 stem->set_property ("direction", scm_int2num (d));
688 head_extents.intersect (max_gap);
689 assert (head_extents.is_empty () || head_extents.length () < 1e-6);
694 /* Set stem's shorten property if unset.
697 take some y-position (chord/beam/nearest?) into account
698 scmify forced-fraction
700 This is done in beam because the shorten has to be uniform over the
704 Beam::set_stem_shorten (Grob *me)
707 shortening looks silly for x staff beams
712 Real forced_fraction = 1.0 * forced_stem_count (me)
713 / visible_stem_count (me);
715 int beam_count = get_beam_count (me);
717 SCM shorten_list = me->get_property ("beamed-stem-shorten");
718 if (shorten_list == SCM_EOL)
721 Real staff_space = Staff_symbol_referencer::staff_space (me);
724 = robust_list_ref (beam_count -1, shorten_list);
725 Real shorten_f = scm_to_double (shorten_elt) * staff_space;
727 /* your similar cute comment here */
728 shorten_f *= forced_fraction;
731 me->set_property ("shorten", scm_make_real (shorten_f));
734 /* Call list of y-dy-callbacks, that handle setting of
737 MAKE_SCHEME_CALLBACK (Beam, after_line_breaking, 1);
739 Beam::after_line_breaking (SCM smob)
741 Grob *me = unsmob_grob (smob);
744 return SCM_UNSPECIFIED;
748 Beam::position_beam (Grob *me)
752 if (to_boolean (me->get_property ("positioning-done")))
755 me->set_property ("positioning-done", SCM_BOOL_T);
757 /* Copy to mutable list. */
758 SCM s = ly_deep_copy (me->get_property ("positions"));
759 me->set_property ("positions", s);
761 if (scm_car (s) == SCM_BOOL_F)
763 // one wonders if such genericity is necessary --hwn.
764 SCM callbacks = me->get_property ("position-callbacks");
765 for (SCM i = callbacks; scm_is_pair (i); i = scm_cdr (i))
766 scm_call_1 (scm_car (i), me->self_scm ());
769 set_stem_lengths (me);
773 set_minimum_dy (Grob *me, Real *dy)
778 If dy is smaller than the smallest quant, we
779 get absurd direction-sign penalties.
782 Real ss = Staff_symbol_referencer::staff_space (me);
783 Real thickness = Beam::get_thickness (me) / ss;
784 Real slt = Staff_symbol_referencer::line_thickness (me) / ss;
785 Real sit = (thickness - slt) / 2;
787 Real hang = 1.0 - (thickness - slt) / 2;
789 *dy = sign (*dy) * (fabs (*dy)
791 (sit <? inter <? hang));
796 Compute a first approximation to the beam slope.
798 MAKE_SCHEME_CALLBACK (Beam, least_squares, 1);
800 Beam::least_squares (SCM smob)
802 Grob *me = unsmob_grob (smob);
804 int count = visible_stem_count (me);
809 me->set_property ("positions", ly_interval2scm (pos));
810 return SCM_UNSPECIFIED;
814 Link_array<Grob> stems
815 = extract_grob_array (me, ly_symbol2scm ("stems"));
816 Grob *commonx = common_refpoint_of_array (stems, me, X_AXIS);
817 Grob *commony = common_refpoint_of_array (stems, me, Y_AXIS);
819 Real my_y = me->relative_coordinate (commony, Y_AXIS);
821 Grob *fvs = first_visible_stem (me);
822 Grob *lvs = last_visible_stem (me);
824 Interval ideal (Stem::get_stem_info (fvs).ideal_y_
825 + fvs->relative_coordinate (commony, Y_AXIS) -my_y,
826 Stem::get_stem_info (lvs).ideal_y_
827 + lvs->relative_coordinate (commony, Y_AXIS) - my_y);
829 Real x0 = first_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
830 for (int i = 0; i < stems.size (); i++)
834 Real x = s->relative_coordinate (commonx, X_AXIS) - x0;
837 Real dx = last_visible_stem (me)->relative_coordinate (commonx, X_AXIS) - x0;
845 Interval chord (Stem::chord_start_y (first_visible_stem (me)),
846 Stem::chord_start_y (last_visible_stem (me)));
848 /* Simple beams (2 stems) on middle line should be allowed to be
851 However, if both stems reach middle line,
852 ideal[LEFT] == ideal[RIGHT] and ideal.delta () == 0.
854 For that case, we apply artificial slope */
855 if (!ideal[LEFT] && chord.delta () && count == 2)
858 Direction d = (Direction) (sign (chord.delta ()) * UP);
859 pos[d] = get_thickness (me) / 2;
868 For broken beams this doesn't work well. In this case, the
869 slope esp. of the first part of a broken beam should predict
870 where the second part goes.
872 me->set_property ("least-squares-dy",
873 scm_make_real (pos[RIGHT] - pos[LEFT]));
877 Array<Offset> ideals;
878 for (int i = 0; i < stems.size (); i++)
881 if (Stem::is_invisible (s))
883 ideals.push (Offset (x_posns[i],
884 Stem::get_stem_info (s).ideal_y_
885 + s->relative_coordinate (commony, Y_AXIS)
889 minimise_least_squares (&slope, &y, ideals);
893 set_minimum_dy (me, &dy);
894 me->set_property ("least-squares-dy", scm_make_real (dy));
895 pos = Interval (y, (y + dy));
899 "position" is relative to the staff.
901 scale_drul (&pos, 1/ Staff_symbol_referencer::staff_space (me));
903 me->set_property ("positions", ly_interval2scm (pos));
905 return SCM_UNSPECIFIED;
909 We can't combine with previous function, since check concave and
910 slope damping comes first.
912 TODO: we should use the concaveness to control the amount of damping
915 MAKE_SCHEME_CALLBACK (Beam, shift_region_to_valid, 1);
917 Beam::shift_region_to_valid (SCM grob)
919 Grob *me = unsmob_grob (grob);
924 Link_array<Grob> stems
925 = extract_grob_array (me, ly_symbol2scm ("stems"));
926 Grob *commonx = common_refpoint_of_array (stems, me, X_AXIS);
927 Grob *commony = common_refpoint_of_array (stems, me, Y_AXIS);
929 Grob *fvs = first_visible_stem (me);
932 return SCM_UNSPECIFIED;
934 Real x0 = fvs->relative_coordinate (commonx, X_AXIS);
935 for (int i = 0; i < stems.size (); i++)
939 Real x = s->relative_coordinate (commonx, X_AXIS) - x0;
943 Grob *lvs = last_visible_stem (me);
945 return SCM_UNSPECIFIED;
947 Real dx = lvs->relative_coordinate (commonx, X_AXIS) - x0;
949 Drul_array<Real> pos = ly_scm2interval (me->get_property ("positions"));
951 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
953 Real dy = pos[RIGHT] - pos[LEFT];
955 Real slope = dy / dx;
958 Shift the positions so that we have a chance of finding good
959 quants (i.e. no short stem failures.)
961 Interval feasible_left_point;
962 feasible_left_point.set_full ();
963 for (int i = 0; i < stems.size (); i++)
966 if (Stem::is_invisible (s))
969 Direction d = Stem::get_direction (s);
972 = Stem::get_stem_info (s).shortest_y_
973 - slope * x_posns [i];
976 left_y is now relative to the stem S. We want relative to
977 ourselves, so translate:
980 += + s->relative_coordinate (commony, Y_AXIS)
981 - me->relative_coordinate (commony, Y_AXIS);
987 feasible_left_point.intersect (flp);
990 if (feasible_left_point.is_empty ())
991 warning (_ ("no viable initial configuration found: may not find good beam slope"));
992 else if (!feasible_left_point.contains (y))
994 if (isinf (feasible_left_point[DOWN]))
995 y = feasible_left_point[UP] - REGION_SIZE;
996 else if (isinf (feasible_left_point[UP]))
997 y = feasible_left_point[DOWN]+ REGION_SIZE;
999 y = feasible_left_point.center ();
1002 pos = Drul_array<Real> (y, (y + dy));
1003 scale_drul (&pos, 1/ Staff_symbol_referencer::staff_space (me));
1005 me->set_property ("positions", ly_interval2scm (pos));
1006 return SCM_UNSPECIFIED;
1009 /* This neat trick is by Werner Lemberg,
1010 damped = tanh (slope)
1011 corresponds with some tables in [Wanske] CHECKME */
1012 MAKE_SCHEME_CALLBACK (Beam, slope_damping, 1);
1014 Beam::slope_damping (SCM smob)
1016 Grob *me = unsmob_grob (smob);
1018 if (visible_stem_count (me) <= 1)
1019 return SCM_UNSPECIFIED;
1021 SCM s = me->get_property ("damping");
1022 Real damping = scm_to_double (s);
1026 Drul_array<Real> pos = ly_scm2interval (me->get_property ("positions"));
1027 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
1029 Real dy = pos[RIGHT] - pos[LEFT];
1031 Grob *fvs = first_visible_stem (me);
1032 Grob *lvs = last_visible_stem (me);
1034 Grob *commonx = fvs->common_refpoint (lvs, X_AXIS);
1036 Real dx = last_visible_stem (me)->relative_coordinate (commonx, X_AXIS)
1037 - first_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
1039 Real slope = dy && dx ? dy / dx : 0;
1041 Real concaveness = robust_scm2double (me->get_property ("concaveness"), 0.0);
1043 slope = 0.6 * tanh (slope) / (damping + concaveness);
1045 Real damped_dy = slope * dx;
1047 set_minimum_dy (me, &damped_dy);
1049 pos[LEFT] += (dy - damped_dy) / 2;
1050 pos[RIGHT] -= (dy - damped_dy) / 2;
1052 scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
1054 me->set_property ("positions", ly_interval2scm (pos));
1056 return SCM_UNSPECIFIED;
1060 Report slice containing the numbers that are both in (car BEAMING)
1064 where_are_the_whole_beams (SCM beaming)
1068 for (SCM s = scm_car (beaming); scm_is_pair (s); s = scm_cdr (s))
1070 if (scm_c_memq (scm_car (s), scm_cdr (beaming)) != SCM_BOOL_F)
1072 l.add_point (scm_to_int (scm_car (s)));
1078 /* Return the Y position of the stem-end, given the Y-left, Y-right
1079 in POS for stem S. This Y position is relative to S. */
1081 Beam::calc_stem_y (Grob *me, Grob *s, Grob ** common,
1083 Drul_array<Real> pos, bool french)
1085 Real beam_translation = get_beam_translation (me);
1087 Real r = s->relative_coordinate (common[X_AXIS], X_AXIS) - xl;
1088 Real dy = pos[RIGHT] - pos[LEFT];
1090 Real stem_y_beam0 = (dy && dx
1095 Direction my_dir = get_grob_direction (s);
1096 SCM beaming = s->get_property ("beaming");
1098 Real stem_y = stem_y_beam0;
1101 Slice bm = where_are_the_whole_beams (beaming);
1102 if (!bm.is_empty ())
1103 stem_y += beam_translation * bm[-my_dir];
1107 Slice bm = Stem::beam_multiplicity (s);
1108 if (!bm.is_empty ())
1109 stem_y += bm[my_dir] * beam_translation;
1112 Real id = me->relative_coordinate (common[Y_AXIS], Y_AXIS)
1113 - s->relative_coordinate (common[Y_AXIS], Y_AXIS);
1119 Hmm. At this time, beam position and slope are determined. Maybe,
1120 stem directions and length should set to relative to the chord's
1121 position of the beam. */
1123 Beam::set_stem_lengths (Grob *me)
1125 Link_array<Grob> stems
1126 = extract_grob_array (me, ly_symbol2scm ("stems"));
1132 for (int a = 2; a--;)
1133 common[a] = common_refpoint_of_array (stems, me, Axis (a));
1135 Drul_array<Real> pos = ly_scm2realdrul (me->get_property ("positions"));
1136 Real staff_space = Staff_symbol_referencer::staff_space (me);
1137 scale_drul (&pos, staff_space);
1141 if (scm_is_number (me->get_property ("gap-count"))
1142 &&scm_to_int (me->get_property ("gap-count")))
1145 thick = get_thickness (me);
1148 // ugh -> use commonx
1149 Grob *fvs = first_visible_stem (me);
1150 Grob *lvs = last_visible_stem (me);
1152 Real xl = fvs ? fvs->relative_coordinate (common[X_AXIS], X_AXIS) : 0.0;
1153 Real xr = lvs ? lvs->relative_coordinate (common[X_AXIS], X_AXIS) : 0.0;
1155 for (int i = 0; i < stems.size (); i++)
1158 if (Stem::is_invisible (s))
1161 bool french = to_boolean (s->get_property ("french-beaming"));
1162 Real stem_y = calc_stem_y (me, s, common,
1164 pos, french && s != lvs && s!= fvs);
1167 Make the stems go up to the end of the beam. This doesn't matter
1168 for normal beams, but for tremolo beams it looks silly otherwise.
1171 stem_y += thick * 0.5 * get_grob_direction (s);
1173 Stem::set_stemend (s, 2* stem_y / staff_space);
1178 Beam::set_beaming (Grob *me, Beaming_info_list *beaming)
1180 Link_array<Grob> stems
1181 = extract_grob_array (me, ly_symbol2scm ("stems"));
1184 for (int i = 0; i < stems.size (); i++)
1187 Don't overwrite user settings.
1192 /* Don't set beaming for outside of outer stems */
1193 if ((d == LEFT && i == 0)
1194 || (d == RIGHT && i == stems.size () -1))
1197 Grob *st = stems[i];
1198 SCM beaming_prop = st->get_property ("beaming");
1199 if (beaming_prop == SCM_EOL
1200 || index_get_cell (beaming_prop, d) == SCM_EOL)
1202 int b = beaming->infos_.elem (i).beams_i_drul_[d];
1204 && i < stems.size () -1
1205 && Stem::is_invisible (st))
1206 b = b <? beaming->infos_.elem (i).beams_i_drul_[-d];
1208 Stem::set_beaming (st, b, d);
1211 while (flip (&d) != LEFT);
1216 Beam::forced_stem_count (Grob *me)
1218 Link_array<Grob> stems
1219 = extract_grob_array (me, ly_symbol2scm ("stems"));
1221 for (int i = 0; i < stems.size (); i++)
1225 if (Stem::is_invisible (s))
1228 /* I can imagine counting those boundaries as a half forced stem,
1229 but let's count them full for now. */
1230 if (abs (Stem::chord_start_y (s)) > 0.1
1231 && (Stem::get_direction (s) != Stem::get_default_dir (s)))
1239 Beam::visible_stem_count (Grob *me)
1241 Link_array<Grob> stems
1242 = extract_grob_array (me, ly_symbol2scm ("stems"));
1244 for (int i = stems.size (); i--;)
1246 if (!Stem::is_invisible (stems[i]))
1253 Beam::first_visible_stem (Grob *me)
1255 Link_array<Grob> stems
1256 = extract_grob_array (me, ly_symbol2scm ("stems"));
1258 for (int i = 0; i < stems.size (); i++)
1260 if (!Stem::is_invisible (stems[i]))
1267 Beam::last_visible_stem (Grob *me)
1269 Link_array<Grob> stems
1270 = extract_grob_array (me, ly_symbol2scm ("stems"));
1271 for (int i = stems.size (); i--;)
1273 if (!Stem::is_invisible (stems[i]))
1282 handle rest under beam (do_post: beams are calculated now)
1283 what about combination of collisions and rest under beam.
1287 rest -> stem -> beam -> interpolate_y_position ()
1289 MAKE_SCHEME_CALLBACK (Beam, rest_collision_callback, 2);
1291 Beam::rest_collision_callback (SCM element_smob, SCM axis)
1293 Grob *rest = unsmob_grob (element_smob);
1294 Axis a = (Axis) scm_to_int (axis);
1296 if (scm_is_number (rest->get_property ("staff-position")))
1297 return scm_int2num (0);
1299 assert (a == Y_AXIS);
1301 Grob *st = unsmob_grob (rest->get_property ("stem"));
1304 return scm_make_real (0.0);
1305 Grob *beam = unsmob_grob (stem->get_property ("beam"));
1307 || !Beam::has_interface (beam)
1308 || !Beam::visible_stem_count (beam))
1309 return scm_make_real (0.0);
1311 Drul_array<Real> pos (0, 0);
1312 SCM s = beam->get_property ("positions");
1313 if (scm_is_pair (s) && scm_is_number (scm_car (s)))
1314 pos = ly_scm2interval (s);
1315 Real staff_space = Staff_symbol_referencer::staff_space (rest);
1317 scale_drul (&pos, staff_space);
1319 Real dy = pos[RIGHT] - pos[LEFT];
1321 // ugh -> use commonx
1322 Real x0 = first_visible_stem (beam)->relative_coordinate (0, X_AXIS);
1323 Real dx = last_visible_stem (beam)->relative_coordinate (0, X_AXIS) - x0;
1324 Real slope = dy && dx ? dy / dx : 0;
1326 Direction d = Stem::get_direction (stem);
1327 Real stem_y = pos[LEFT] + (stem->relative_coordinate (0, X_AXIS) - x0) * slope;
1329 Real beam_translation = get_beam_translation (beam);
1330 Real beam_thickness = Beam::get_thickness (beam);
1333 TODO: this is not strictly correct for 16th knee beams.
1336 = Stem::beam_multiplicity (stem).length () + 1;
1338 Real height_of_my_beams = beam_thickness / 2
1339 + (beam_count - 1) * beam_translation;
1340 Real beam_y = stem_y - d * height_of_my_beams;
1342 Grob *common_y = rest->common_refpoint (beam, Y_AXIS);
1344 Real rest_dim = rest->extent (common_y, Y_AXIS)[d];
1345 Real minimum_distance
1346 = + staff_space * (robust_scm2double (stem->get_property ("stemlet-length"), 0.0)
1347 + robust_scm2double (rest->get_property ("minimum-distance"), 0.0));
1349 Real shift = d * (((beam_y - d * minimum_distance) - rest_dim) * d <? 0.0);
1351 shift /= staff_space;
1352 Real rad = Staff_symbol_referencer::line_count (rest) * staff_space / 2;
1354 /* Always move discretely by half spaces */
1355 shift = ceil (fabs (shift * 2.0)) / 2.0 * sign (shift);
1357 /* Inside staff, move by whole spaces*/
1358 if ((rest->extent (common_y, Y_AXIS)[d] + staff_space * shift) * d
1360 || (rest->extent (common_y, Y_AXIS)[-d] + staff_space * shift) * -d
1362 shift = ceil (fabs (shift)) *sign (shift);
1364 return scm_make_real (staff_space * shift);
1368 Beam::is_knee (Grob *me)
1370 SCM k = me->get_property ("knee");
1371 if (scm_is_bool (k))
1372 return ly_scm2bool (k);
1376 for (SCM s = me->get_property ("stems"); scm_is_pair (s); s = scm_cdr (s))
1378 Direction dir = get_grob_direction (unsmob_grob (scm_car (s)));
1387 me->set_property ("knee", ly_bool2scm (knee));
1393 Beam::get_direction_beam_count (Grob *me, Direction d)
1395 Link_array<Grob> stems
1396 = extract_grob_array (me, ly_symbol2scm ("stems"));
1399 for (int i = stems.size (); i--;)
1402 Should we take invisible stems into account?
1404 if (Stem::get_direction (stems[i]) == d)
1405 bc = bc >? (Stem::beam_multiplicity (stems[i]).length () + 1);
1411 ADD_INTERFACE (Beam, "beam-interface",
1413 "The @code{thickness} property is the weight of beams, and is measured "
1415 "knee positioning-done position-callbacks "
1416 "concaveness dir-function quant-score auto-knee-gap gap "
1417 "gap-count chord-tremolo beamed-stem-shorten shorten least-squares-dy "
1418 "damping inspect-quants flag-width-function neutral-direction positions space-function "