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.
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 Pointer_group_interface::add_grob (me, ly_symbol2scm ("stems"), s);
52 s->add_dependency (me);
54 assert (!Stem::get_beam (s));
55 s->set_object ("beam", me->self_scm ());
57 add_bound_item (dynamic_cast<Spanner *> (me), dynamic_cast<Item *> (s));
61 Beam::get_thickness (Grob *me)
63 return robust_scm2double (me->get_property ("thickness"), 0)
64 * Staff_symbol_referencer::staff_space (me);
67 /* Return the translation between 2 adjoining beams. */
69 Beam::get_beam_translation (Grob *me)
71 SCM func = me->get_property ("space-function");
73 if (ly_is_procedure (func))
75 SCM s = scm_call_2 (func, me->self_scm (), scm_from_int (get_beam_count (me)));
76 return scm_to_double (s);
82 /* Maximum beam_count. */
84 Beam::get_beam_count (Grob *me)
88 extract_grob_set (me, "stems", stems);
89 for (int i = 0; i < stems.size (); i++)
91 Grob *stem = stems[i];
92 m = max (m, (Stem::beam_multiplicity (stem).length () + 1));
98 Space return space between beams.
100 MAKE_SCHEME_CALLBACK (Beam, space_function, 2);
102 Beam::space_function (SCM smob, SCM beam_count)
104 Grob *me = unsmob_grob (smob);
106 Real staff_space = Staff_symbol_referencer::staff_space (me);
107 Real line = Staff_symbol_referencer::line_thickness (me);
108 Real thickness = get_thickness (me);
110 Real beam_translation = scm_to_int (beam_count) < 4
111 ? (2 * staff_space + line - thickness) / 2.0
112 : (3 * staff_space + line - thickness) / 3.0;
114 return scm_from_double (beam_translation);
117 /* After pre-processing all directions should be set.
118 Several post-processing routines (stem, slur, script) need stem/beam
120 Currenly, this means that beam has set all stem's directions.
121 [Alternatively, stems could set its own directions, according to
122 their beam, during 'final-pre-processing'.] */
123 MAKE_SCHEME_CALLBACK (Beam, before_line_breaking, 1);
125 Beam::before_line_breaking (SCM smob)
127 Grob *me = unsmob_grob (smob);
129 /* Beams with less than 2 two stems don't make much sense, but could happen
134 For a beam that only has one stem, we try to do some disappearance magic:
135 we revert the flag, and move on to The Eternal Engraving Fields. */
137 int count = visible_stem_count (me);
140 extract_grob_set (me, "stems", stems);
141 if (stems.size () == 1)
143 me->warning (_ ("removing beam with less than two stems"));
145 stems[0]->set_object ("beam", SCM_EOL);
148 return SCM_UNSPECIFIED;
150 else if (stems.size () == 0)
153 return SCM_UNSPECIFIED;
158 Direction d = get_default_dir (me);
160 consider_auto_knees (me);
161 set_stem_directions (me, d);
165 set_stem_shorten (me);
171 /* We want a maximal number of shared beams, but if there is choice, we
172 * take the one that is closest to the end of the stem. This is for
184 position_with_maximal_common_beams (SCM left_beaming, SCM right_beaming,
188 Slice lslice = int_list_to_slice (scm_cdr (left_beaming));
192 for (int i = lslice[-left_dir];
193 (i - lslice[left_dir]) * left_dir <= 0; i += left_dir)
196 for (SCM s = scm_car (right_beaming); scm_is_pair (s); s = scm_cdr (s))
198 int k = -right_dir * scm_to_int (scm_car (s)) + i;
199 if (scm_c_memq (scm_from_int (k), left_beaming) != SCM_BOOL_F)
203 if (count >= best_count)
214 Beam::connect_beams (Grob *me)
216 extract_grob_set (me, "stems", stems);
219 last_int.set_empty ();
220 SCM last_beaming = SCM_EOL;
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,
238 if (d == RIGHT && i == stems.size () - 1)
241 new_slice.set_empty ();
242 SCM s = index_get_cell (this_beaming, d);
243 for (; scm_is_pair (s); s = scm_cdr (s))
246 = start_point - this_dir * scm_to_int (scm_car (s));
248 new_slice.add_point (new_beam_pos);
249 scm_set_car_x (s, scm_from_int (new_beam_pos));
252 while (flip (&d) != LEFT);
254 if (!new_slice.is_empty ())
255 last_int = new_slice;
259 scm_set_car_x (this_beaming, SCM_EOL);
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 (i == stems.size () -1)
270 scm_set_cdr_x (this_beaming, SCM_EOL);
272 if (scm_ilength (scm_cdr (this_beaming)) > 0)
274 last_beaming = this_beaming;
281 I really enjoy spaghetti, but spaghetti should be kept on a plate
282 with a little garlic and olive oil. This is too much.
286 MAKE_SCHEME_CALLBACK (Beam, print, 1);
288 Beam::print (SCM grob)
290 Spanner *me = unsmob_spanner (grob);
293 extract_grob_set (me, "stems", stems);
294 Grob *xcommon = common_refpoint_of_array (stems, me, X_AXIS);
296 xcommon = me->get_bound (LEFT)->common_refpoint (xcommon, X_AXIS);
297 xcommon = me->get_bound (RIGHT)->common_refpoint (xcommon, X_AXIS);
300 if (visible_stem_count (me))
302 // ugh -> use commonx
303 x0 = first_visible_stem (me)->relative_coordinate (xcommon, X_AXIS);
304 dx = last_visible_stem (me)->relative_coordinate (xcommon, X_AXIS) - x0;
308 x0 = stems[0]->relative_coordinate (xcommon, X_AXIS);
309 dx = stems.top ()->relative_coordinate (xcommon, X_AXIS) - x0;
312 SCM posns = me->get_property ("positions");
313 Drul_array<Real> pos;
314 if (!is_number_pair (posns))
316 programming_error ("no beam positions?");
317 pos = Interval (0, 0);
320 pos = ly_scm2realdrul (posns);
322 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
324 Real dy = pos[RIGHT] - pos[LEFT];
325 Real slope = (dy && dx) ? dy / dx : 0;
327 Real thick = get_thickness (me);
328 Real bdy = get_beam_translation (me);
330 SCM last_beaming = SCM_EOL;
331 Real last_xposn = -1;
332 Real last_stem_width = -1;
334 Real gap_length = robust_scm2double (me->get_property ("gap"), 0.0);
337 Real lt = me->get_layout ()->get_dimension (ly_symbol2scm ("linethickness"));
339 for (int i = 0; i <= stems.size (); i++)
341 Grob *stem = (i < stems.size ()) ? stems[i] : 0;
343 SCM this_beaming = stem ? stem->get_property ("beaming") : SCM_EOL;
344 Real xposn = stem ? stem->relative_coordinate (xcommon, X_AXIS) : 0.0;
345 Real stem_width = stem ? robust_scm2double (stem->get_property ("thickness"), 1.0) * lt : 0;
346 Direction stem_dir = stem ? to_dir (stem->get_property ("direction")) : CENTER;
348 We do the space left of ST, with lfliebertjes pointing to the
349 right from the left stem, and rfliebertjes pointing left from
352 SCM left = (i > 0) ? scm_cdr (last_beaming) : SCM_EOL;
353 SCM right = stem ? scm_car (this_beaming) : SCM_EOL;
355 Array<int> full_beams;
356 Array<int> lfliebertjes;
357 Array<int> rfliebertjes;
360 scm_is_pair (s); s = scm_cdr (s))
362 int b = scm_to_int (scm_car (s));
363 if (scm_c_memq (scm_car (s), right) != SCM_BOOL_F)
366 lfliebertjes.push (b);
369 scm_is_pair (s); s = scm_cdr (s))
371 int b = scm_to_int (scm_car (s));
372 if (scm_c_memq (scm_car (s), left) == SCM_BOOL_F)
373 rfliebertjes.push (b);
376 Drul_array<Real> break_overshoot
377 = robust_scm2drul (me->get_property ("break-overshoot"),
378 Drul_array<Real> (-0.5, 0.0));
380 Real w = (i > 0 && stem)
381 ? (xposn - last_xposn)
382 : break_overshoot[ (i == 0) ? LEFT : RIGHT];
384 Real stem_offset = 0.0;
387 w += last_stem_width / 2;
388 stem_offset = -last_stem_width / 2;
394 Real blot = me->get_layout ()->get_dimension (ly_symbol2scm ("blotdiameter"));
395 Stencil whole = Lookup::beam (slope, w, thick, blot);
399 if (scm_is_number (me->get_property ("gap-count")))
401 gap_count = scm_to_int (me->get_property ("gap-count"));
402 gapped = Lookup::beam (slope, w - 2 * gap_length, thick, blot);
404 full_beams.sort (default_compare);
406 full_beams.reverse ();
410 for (int j = full_beams.size (); j--;)
417 b.translate_axis (gap_length, X_AXIS);
419 b.translate_axis (last_xposn - x0 + stem_offset, X_AXIS);
420 b.translate_axis (slope * (last_xposn - x0) + bdy * full_beams[j], Y_AXIS);
422 the_beam.add_stencil (b);
425 if (lfliebertjes.size () || rfliebertjes.size ())
431 int t = Stem::duration_log (stem);
433 SCM proc = me->get_property ("flag-width-function");
434 SCM result = scm_call_1 (proc, scm_from_int (t));
435 nw_f = scm_to_double (result);
438 nw_f = break_overshoot[RIGHT] / 2;
440 /* Half beam should be one note-width,
441 but let's make sure two half-beams never touch */
445 rw = min (nw_f, ((xposn - last_xposn) / 2));
447 rw = xposn - me->get_bound (LEFT)->extent (xcommon, X_AXIS)[RIGHT]
448 + break_overshoot[LEFT];
451 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->get_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 tm = *unsmob_stencil (Text_interface::interpret_markup
508 (me->get_layout ()->self_scm (), properties, quant_score));
509 the_beam.add_at_edge (Y_AXIS, stem_dir, tm, 1.0, 0);
513 return the_beam.smobbed_copy ();
517 Beam::get_default_dir (Grob *me)
519 Drul_array<int> total;
520 total[UP] = total[DOWN] = 0;
521 Drul_array<int> count;
522 count[UP] = count[DOWN] = 0;
525 extract_grob_set (me, "stems", stems);
527 for (int i = 0; i < stems.size (); i++)
531 Direction sd = get_grob_direction (s);
533 int center_distance = max (int (- d * Stem::head_positions (s) [-d]), 0);
534 int current = sd ? (1 + d * sd) / 2 : center_distance;
542 while (flip (&d) != DOWN);
544 SCM func = me->get_property ("dir-function");
545 SCM s = scm_call_2 (func,
546 scm_cons (scm_from_int (count[UP]),
547 scm_from_int (count[DOWN])),
548 scm_cons (scm_from_int (total[UP]),
549 scm_from_int (total[DOWN])));
551 if (scm_is_number (s) && scm_to_int (s))
554 /* If dir is not determined: get default */
555 return to_dir (me->get_property ("neutral-direction"));
558 /* Set all stems with non-forced direction to beam direction.
559 Urg: non-forced should become `without/with unforced' direction,
560 once stem gets cleaned-up. */
562 Beam::set_stem_directions (Grob *me, Direction d)
564 extract_grob_set (me, "stems", stems);
566 for (int i = 0; i < stems.size (); i++)
570 SCM forcedir = s->get_property ("direction");
571 if (!to_dir (forcedir))
572 set_grob_direction (s, d);
577 Only try horizontal beams for knees. No reliable detection of
578 anything else is possible here, since we don't know funky-beaming
579 settings, or X-distances (slopes!) People that want sloped
580 knee-beams, should set the directions manually.
585 this routine should take into account the stemlength scoring
586 of a possible knee/nonknee beam.
589 Beam::consider_auto_knees (Grob *me)
591 SCM scm = me->get_property ("auto-knee-gap");
592 if (!scm_is_number (scm))
599 extract_grob_set (me, "stems", stems);
601 Grob *common = common_refpoint_of_array (stems, me, Y_AXIS);
602 Real staff_space = Staff_symbol_referencer::staff_space (me);
604 Array<Interval> head_extents_array;
605 for (int i = 0; i < stems.size (); i++)
607 Grob *stem = stems[i];
608 if (Stem::is_invisible (stem))
611 Interval head_extents = Stem::head_positions (stem);
612 if (!head_extents.is_empty ())
614 head_extents[LEFT] += -1;
615 head_extents[RIGHT] += 1;
616 head_extents *= staff_space * 0.5;
619 We could subtract beam Y position, but this routine only
620 sets stem directions, a constant shift does not have an
623 head_extents += stem->relative_coordinate (common, Y_AXIS);
625 if (to_dir (stem->get_property ("direction")))
627 Direction stemdir = to_dir (stem->get_property ("direction"));
628 head_extents[-stemdir] = -stemdir * infinity_f;
631 head_extents_array.push (head_extents);
633 gaps.remove_interval (head_extents);
637 Real max_gap_len = 0.0;
639 for (int i = gaps.allowed_regions_.size () -1; i >= 0; i--)
641 Interval gap = gaps.allowed_regions_[i];
644 the outer gaps are not knees.
646 if (isinf (gap[LEFT]) || isinf (gap[RIGHT]))
649 if (gap.length () >= max_gap_len)
651 max_gap_len = gap.length ();
656 Real beam_translation = get_beam_translation (me);
657 Real beam_thickness = Beam::get_thickness (me);
658 int beam_count = Beam::get_beam_count (me);
659 Real height_of_beams = beam_thickness / 2
660 + (beam_count - 1) * beam_translation;
661 Real threshold = scm_to_double (scm) + height_of_beams;
663 if (max_gap_len > threshold)
666 for (int i = 0; i < stems.size (); i++)
668 Grob *stem = stems[i];
669 if (Stem::is_invisible (stem))
672 Interval head_extents = head_extents_array[j++];
674 Direction d = (head_extents.center () < max_gap.center ())
677 stem->set_property ("direction", scm_from_int (d));
679 head_extents.intersect (max_gap);
680 assert (head_extents.is_empty () || head_extents.length () < 1e-6);
685 /* Set stem's shorten property if unset.
688 take some y-position (chord/beam/nearest?) into account
689 scmify forced-fraction
691 This is done in beam because the shorten has to be uniform over the
695 Beam::set_stem_shorten (Grob *me)
698 shortening looks silly for x staff beams
703 Real forced_fraction = 1.0 * forced_stem_count (me)
704 / visible_stem_count (me);
706 int beam_count = get_beam_count (me);
708 SCM shorten_list = me->get_property ("beamed-stem-shorten");
709 if (shorten_list == SCM_EOL)
712 Real staff_space = Staff_symbol_referencer::staff_space (me);
715 = robust_list_ref (beam_count -1, shorten_list);
716 Real shorten_f = scm_to_double (shorten_elt) * staff_space;
718 /* your similar cute comment here */
719 shorten_f *= forced_fraction;
722 me->set_property ("shorten", scm_from_double (shorten_f));
725 /* Call list of y-dy-callbacks, that handle setting of
728 MAKE_SCHEME_CALLBACK (Beam, after_line_breaking, 1);
730 Beam::after_line_breaking (SCM smob)
732 Grob *me = unsmob_grob (smob);
735 return SCM_UNSPECIFIED;
739 Beam::position_beam (Grob *me)
743 if (to_boolean (me->get_property ("positioning-done")))
746 me->set_property ("positioning-done", SCM_BOOL_T);
748 /* Copy to mutable list. */
749 SCM s = ly_deep_copy (me->get_property ("positions"));
750 me->set_property ("positions", s);
752 if (scm_car (s) == SCM_BOOL_F)
754 // one wonders if such genericity is necessary --hwn.
755 SCM callbacks = me->get_property ("position-callbacks");
756 for (SCM i = callbacks; scm_is_pair (i); i = scm_cdr (i))
757 scm_call_1 (scm_car (i), me->self_scm ());
760 set_stem_lengths (me);
764 set_minimum_dy (Grob *me, Real *dy)
769 If dy is smaller than the smallest quant, we
770 get absurd direction-sign penalties.
773 Real ss = Staff_symbol_referencer::staff_space (me);
774 Real thickness = Beam::get_thickness (me) / ss;
775 Real slt = Staff_symbol_referencer::line_thickness (me) / ss;
776 Real sit = (thickness - slt) / 2;
778 Real hang = 1.0 - (thickness - slt) / 2;
780 *dy = sign (*dy) * max (fabs (*dy),
781 min (min (sit, inter), hang));
786 Compute a first approximation to the beam slope.
788 MAKE_SCHEME_CALLBACK (Beam, least_squares, 1);
790 Beam::least_squares (SCM smob)
792 Grob *me = unsmob_grob (smob);
794 int count = visible_stem_count (me);
799 me->set_property ("positions", ly_interval2scm (pos));
800 return SCM_UNSPECIFIED;
804 extract_grob_set (me, "stems", stems);
805 Grob *commonx = common_refpoint_of_array (stems, me, X_AXIS);
806 Grob *commony = common_refpoint_of_array (stems, me, Y_AXIS);
808 Real my_y = me->relative_coordinate (commony, Y_AXIS);
810 Grob *fvs = first_visible_stem (me);
811 Grob *lvs = last_visible_stem (me);
813 Interval ideal (Stem::get_stem_info (fvs).ideal_y_
814 + fvs->relative_coordinate (commony, Y_AXIS) -my_y,
815 Stem::get_stem_info (lvs).ideal_y_
816 + lvs->relative_coordinate (commony, Y_AXIS) - my_y);
818 Real x0 = first_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
819 for (int i = 0; i < stems.size (); i++)
823 Real x = s->relative_coordinate (commonx, X_AXIS) - x0;
826 Real dx = last_visible_stem (me)->relative_coordinate (commonx, X_AXIS) - x0;
834 Interval chord (Stem::chord_start_y (first_visible_stem (me)),
835 Stem::chord_start_y (last_visible_stem (me)));
837 /* Simple beams (2 stems) on middle line should be allowed to be
840 However, if both stems reach middle line,
841 ideal[LEFT] == ideal[RIGHT] and ideal.delta () == 0.
843 For that case, we apply artificial slope */
844 if (!ideal[LEFT] && chord.delta () && count == 2)
847 Direction d = (Direction) (sign (chord.delta ()) * UP);
848 pos[d] = get_thickness (me) / 2;
855 For broken beams this doesn't work well. In this case, the
856 slope esp. of the first part of a broken beam should predict
857 where the second part goes.
859 me->set_property ("least-squares-dy",
860 scm_from_double (pos[RIGHT] - pos[LEFT]));
864 Array<Offset> ideals;
865 for (int i = 0; i < stems.size (); i++)
868 if (Stem::is_invisible (s))
870 ideals.push (Offset (x_posns[i],
871 Stem::get_stem_info (s).ideal_y_
872 + s->relative_coordinate (commony, Y_AXIS)
876 minimise_least_squares (&slope, &y, ideals);
880 set_minimum_dy (me, &dy);
881 me->set_property ("least-squares-dy", scm_from_double (dy));
882 pos = Interval (y, (y + dy));
886 "position" is relative to the staff.
888 scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
890 me->set_property ("positions", ly_interval2scm (pos));
892 return SCM_UNSPECIFIED;
896 We can't combine with previous function, since check concave and
897 slope damping comes first.
899 TODO: we should use the concaveness to control the amount of damping
902 MAKE_SCHEME_CALLBACK (Beam, shift_region_to_valid, 1);
904 Beam::shift_region_to_valid (SCM grob)
906 Grob *me = unsmob_grob (grob);
911 extract_grob_set (me, "stems", stems);
912 Grob *commonx = common_refpoint_of_array (stems, me, X_AXIS);
913 Grob *commony = common_refpoint_of_array (stems, me, Y_AXIS);
915 Grob *fvs = first_visible_stem (me);
918 return SCM_UNSPECIFIED;
920 Real x0 = fvs->relative_coordinate (commonx, X_AXIS);
921 for (int i = 0; i < stems.size (); i++)
925 Real x = s->relative_coordinate (commonx, X_AXIS) - x0;
929 Grob *lvs = last_visible_stem (me);
931 return SCM_UNSPECIFIED;
933 Real dx = lvs->relative_coordinate (commonx, X_AXIS) - x0;
935 Drul_array<Real> pos = ly_scm2interval (me->get_property ("positions"));
937 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
939 Real dy = pos[RIGHT] - pos[LEFT];
941 Real slope = dx ? (dy / dx) : 0.0;
944 Shift the positions so that we have a chance of finding good
945 quants (i.e. no short stem failures.)
947 Interval feasible_left_point;
948 feasible_left_point.set_full ();
949 for (int i = 0; i < stems.size (); i++)
952 if (Stem::is_invisible (s))
955 Direction d = Stem::get_direction (s);
958 = Stem::get_stem_info (s).shortest_y_
959 - slope * x_posns [i];
962 left_y is now relative to the stem S. We want relative to
963 ourselves, so translate:
966 += + s->relative_coordinate (commony, Y_AXIS)
967 - me->relative_coordinate (commony, Y_AXIS);
973 feasible_left_point.intersect (flp);
976 if (feasible_left_point.is_empty ())
977 warning (_ ("no viable initial configuration found: may not find good beam slope"));
978 else if (!feasible_left_point.contains (y))
980 const int REGION_SIZE = 2; // UGH UGH
981 if (isinf (feasible_left_point[DOWN]))
982 y = feasible_left_point[UP] - REGION_SIZE;
983 else if (isinf (feasible_left_point[UP]))
984 y = feasible_left_point[DOWN]+ REGION_SIZE;
986 y = feasible_left_point.center ();
989 pos = Drul_array<Real> (y, (y + dy));
990 scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
992 me->set_property ("positions", ly_interval2scm (pos));
993 return SCM_UNSPECIFIED;
996 /* This neat trick is by Werner Lemberg,
997 damped = tanh (slope)
998 corresponds with some tables in [Wanske] CHECKME */
999 MAKE_SCHEME_CALLBACK (Beam, slope_damping, 1);
1001 Beam::slope_damping (SCM smob)
1003 Grob *me = unsmob_grob (smob);
1005 if (visible_stem_count (me) <= 1)
1006 return SCM_UNSPECIFIED;
1008 SCM s = me->get_property ("damping");
1009 Real damping = scm_to_double (s);
1013 Drul_array<Real> pos = ly_scm2interval (me->get_property ("positions"));
1014 scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
1016 Real dy = pos[RIGHT] - pos[LEFT];
1018 Grob *fvs = first_visible_stem (me);
1019 Grob *lvs = last_visible_stem (me);
1021 Grob *commonx = fvs->common_refpoint (lvs, X_AXIS);
1023 Real dx = last_visible_stem (me)->relative_coordinate (commonx, X_AXIS)
1024 - first_visible_stem (me)->relative_coordinate (commonx, X_AXIS);
1026 Real slope = dy && dx ? dy / dx : 0;
1028 Real concaveness = robust_scm2double (me->get_property ("concaveness"), 0.0);
1030 slope = 0.6 * tanh (slope) / (damping + concaveness);
1032 Real damped_dy = slope * dx;
1034 set_minimum_dy (me, &damped_dy);
1036 pos[LEFT] += (dy - damped_dy) / 2;
1037 pos[RIGHT] -= (dy - damped_dy) / 2;
1039 scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
1041 me->set_property ("positions", ly_interval2scm (pos));
1043 return SCM_UNSPECIFIED;
1047 Report slice containing the numbers that are both in (car BEAMING)
1051 where_are_the_whole_beams (SCM beaming)
1055 for (SCM s = scm_car (beaming); scm_is_pair (s); s = scm_cdr (s))
1057 if (scm_c_memq (scm_car (s), scm_cdr (beaming)) != SCM_BOOL_F)
1059 l.add_point (scm_to_int (scm_car (s)));
1065 /* Return the Y position of the stem-end, given the Y-left, Y-right
1066 in POS for stem S. This Y position is relative to S. */
1068 Beam::calc_stem_y (Grob *me, Grob *s, Grob ** common,
1070 Drul_array<Real> pos, bool french)
1072 Real beam_translation = get_beam_translation (me);
1074 Real r = s->relative_coordinate (common[X_AXIS], X_AXIS) - xl;
1075 Real dy = pos[RIGHT] - pos[LEFT];
1077 Real stem_y_beam0 = (dy && dx
1082 Direction my_dir = get_grob_direction (s);
1083 SCM beaming = s->get_property ("beaming");
1085 Real stem_y = stem_y_beam0;
1088 Slice bm = where_are_the_whole_beams (beaming);
1089 if (!bm.is_empty ())
1090 stem_y += beam_translation * bm[-my_dir];
1094 Slice bm = Stem::beam_multiplicity (s);
1095 if (!bm.is_empty ())
1096 stem_y += bm[my_dir] * beam_translation;
1099 Real id = me->relative_coordinate (common[Y_AXIS], Y_AXIS)
1100 - s->relative_coordinate (common[Y_AXIS], Y_AXIS);
1106 Hmm. At this time, beam position and slope are determined. Maybe,
1107 stem directions and length should set to relative to the chord's
1108 position of the beam. */
1110 Beam::set_stem_lengths (Grob *me)
1112 extract_grob_set (me, "stems", stems);
1117 for (int a = 2; a--;)
1118 common[a] = common_refpoint_of_array (stems, me, Axis (a));
1120 Drul_array<Real> pos = ly_scm2realdrul (me->get_property ("positions"));
1121 Real staff_space = Staff_symbol_referencer::staff_space (me);
1122 scale_drul (&pos, staff_space);
1126 if (scm_is_number (me->get_property ("gap-count"))
1127 &&scm_to_int (me->get_property ("gap-count")))
1130 thick = get_thickness (me);
1133 // ugh -> use commonx
1134 Grob *fvs = first_visible_stem (me);
1135 Grob *lvs = last_visible_stem (me);
1137 Real xl = fvs ? fvs->relative_coordinate (common[X_AXIS], X_AXIS) : 0.0;
1138 Real xr = lvs ? lvs->relative_coordinate (common[X_AXIS], X_AXIS) : 0.0;
1140 for (int i = 0; i < stems.size (); i++)
1143 if (Stem::is_invisible (s))
1146 bool french = to_boolean (s->get_property ("french-beaming"));
1147 Real stem_y = calc_stem_y (me, s, common,
1149 pos, french && s != lvs && s!= fvs);
1152 Make the stems go up to the end of the beam. This doesn't matter
1153 for normal beams, but for tremolo beams it looks silly otherwise.
1156 stem_y += thick * 0.5 * get_grob_direction (s);
1158 Stem::set_stemend (s, 2 * stem_y / staff_space);
1163 Beam::set_beaming (Grob *me, Beaming_info_list *beaming)
1165 extract_grob_set (me, "stems", stems);
1168 for (int i = 0; i < stems.size (); i++)
1171 Don't overwrite user settings.
1176 /* Don't set beaming for outside of outer stems */
1177 if ((d == LEFT && i == 0)
1178 || (d == RIGHT && i == stems.size () -1))
1181 Grob *stem = stems[i];
1182 SCM beaming_prop = stem->get_property ("beaming");
1183 if (beaming_prop == SCM_EOL
1184 || index_get_cell (beaming_prop, d) == SCM_EOL)
1186 int b = beaming->infos_.elem (i).beams_i_drul_[d];
1188 && i < stems.size () -1
1189 && Stem::is_invisible (stem))
1190 b = min (b, beaming->infos_.elem (i).beams_i_drul_[-d]);
1192 Stem::set_beaming (stem, b, d);
1195 while (flip (&d) != LEFT);
1200 Beam::forced_stem_count (Grob *me)
1202 extract_grob_set (me, "stems", stems);
1205 for (int i = 0; i < stems.size (); i++)
1209 if (Stem::is_invisible (s))
1212 /* I can imagine counting those boundaries as a half forced stem,
1213 but let's count them full for now. */
1214 if (abs (Stem::chord_start_y (s)) > 0.1
1215 && (Stem::get_direction (s) != Stem::get_default_dir (s)))
1222 Beam::visible_stem_count (Grob *me)
1224 extract_grob_set (me, "stems", stems);
1226 for (int i = stems.size (); i--;)
1228 if (!Stem::is_invisible (stems[i]))
1235 Beam::first_visible_stem (Grob *me)
1237 extract_grob_set (me, "stems", stems);
1239 for (int i = 0; i < stems.size (); i++)
1241 if (!Stem::is_invisible (stems[i]))
1248 Beam::last_visible_stem (Grob *me)
1250 extract_grob_set (me, "stems", stems);
1252 for (int i = stems.size (); i--;)
1254 if (!Stem::is_invisible (stems[i]))
1263 handle rest under beam (do_post: beams are calculated now)
1264 what about combination of collisions and rest under beam.
1268 rest -> stem -> beam -> interpolate_y_position ()
1270 MAKE_SCHEME_CALLBACK (Beam, rest_collision_callback, 2);
1272 Beam::rest_collision_callback (SCM element_smob, SCM axis)
1274 Grob *rest = unsmob_grob (element_smob);
1277 if (scm_is_number (rest->get_property ("staff-position")))
1278 return scm_from_int (0);
1280 assert (scm_to_int (axis) == Y_AXIS);
1282 Grob *st = unsmob_grob (rest->get_object ("stem"));
1285 return scm_from_double (0.0);
1286 Grob *beam = unsmob_grob (stem->get_object ("beam"));
1288 || !Beam::has_interface (beam)
1289 || !Beam::visible_stem_count (beam))
1290 return scm_from_double (0.0);
1292 Drul_array<Real> pos (0, 0);
1293 SCM s = beam->get_property ("positions");
1294 if (scm_is_pair (s) && scm_is_number (scm_car (s)))
1295 pos = ly_scm2interval (s);
1299 UGH. TODO: fix dependency tracking.
1301 position_beam (beam);
1302 pos = ly_scm2interval (beam->get_property ("positions"));
1305 Real staff_space = Staff_symbol_referencer::staff_space (rest);
1307 scale_drul (&pos, staff_space);
1309 Real dy = pos[RIGHT] - pos[LEFT];
1311 // ugh -> use commonx
1312 Real x0 = first_visible_stem (beam)->relative_coordinate (0, X_AXIS);
1313 Real dx = last_visible_stem (beam)->relative_coordinate (0, X_AXIS) - x0;
1314 Real slope = dy && dx ? dy / dx : 0;
1316 Direction d = Stem::get_direction (stem);
1317 Real stem_y = pos[LEFT] + (stem->relative_coordinate (0, X_AXIS) - x0) * slope;
1319 Real beam_translation = get_beam_translation (beam);
1320 Real beam_thickness = Beam::get_thickness (beam);
1323 TODO: this is not strictly correct for 16th knee beams.
1326 = Stem::beam_multiplicity (stem).length () + 1;
1328 Real height_of_my_beams = beam_thickness / 2
1329 + (beam_count - 1) * beam_translation;
1330 Real beam_y = stem_y - d * height_of_my_beams;
1332 Grob *common_y = rest->common_refpoint (beam, Y_AXIS);
1334 Real rest_dim = rest->extent (common_y, Y_AXIS)[d];
1335 Real minimum_distance
1336 = + staff_space * (robust_scm2double (stem->get_property ("stemlet-length"), 0.0)
1337 + robust_scm2double (rest->get_property ("minimum-distance"), 0.0));
1339 Real shift = d * min (((beam_y - d * minimum_distance) - rest_dim) * d, 0.0);
1341 shift /= staff_space;
1342 Real rad = Staff_symbol_referencer::line_count (rest) * staff_space / 2;
1344 /* Always move discretely by half spaces */
1345 shift = ceil (fabs (shift * 2.0)) / 2.0 * sign (shift);
1347 /* Inside staff, move by whole spaces*/
1348 if ((rest->extent (common_y, Y_AXIS)[d] + staff_space * shift) * d
1350 || (rest->extent (common_y, Y_AXIS)[-d] + staff_space * shift) * -d
1352 shift = ceil (fabs (shift)) * sign (shift);
1354 return scm_from_double (staff_space * shift);
1358 Beam::is_knee (Grob *me)
1360 SCM k = me->get_property ("knee");
1361 if (scm_is_bool (k))
1362 return ly_scm2bool (k);
1366 extract_grob_set (me, "stems", stems);
1367 for (int i = stems.size (); i--;)
1369 Direction dir = get_grob_direction (stems[i]);
1378 me->set_property ("knee", ly_bool2scm (knee));
1384 Beam::get_direction_beam_count (Grob *me, Direction d)
1386 extract_grob_set (me, "stems", stems);
1389 for (int i = stems.size (); i--;)
1392 Should we take invisible stems into account?
1394 if (Stem::get_direction (stems[i]) == d)
1395 bc = max (bc, (Stem::beam_multiplicity (stems[i]).length () + 1));
1401 ADD_INTERFACE (Beam, "beam-interface",
1403 "The @code{thickness} property is the weight of beams, "
1404 "measured in staffspace",
1406 "beamed-stem-shorten "
1413 "flag-width-function "
1419 "neutral-direction "
1420 "position-callbacks "