2 beam.cc -- implement Beam
4 source file of the GNU LilyPond music typesetter
6 (c) 1997--2000 Han-Wen Nienhuys <hanwen@cs.uu.nl>
7 Jan Nieuwenhuizen <janneke@gnu.org>
14 * move paper vars to scm
19 #include <math.h> // tanh.
21 #include "directional-element-interface.hh"
23 #include "dimensions.hh"
27 #include "least-squares.hh"
29 #include "paper-def.hh"
31 #include "group-interface.hh"
32 #include "staff-symbol-referencer.hh"
33 #include "cross-staff.hh"
34 #include "lily-guile.icc"
38 Group_interface g (this, "stems");
43 Beam::add_stem (Stem*s)
45 Group_interface gi (this, "stems");
48 s->add_dependency (this);
50 assert (!s->beam_l ());
51 s->set_elt_property ("beam", self_scm_);
53 if (!get_bound (LEFT))
60 Beam::get_multiplicity () const
63 for (SCM s = get_elt_property ("stems"); gh_pair_p (s); s = gh_cdr (s))
65 Score_element * sc = unsmob_element (gh_car (s));
67 if (Stem * st = dynamic_cast<Stem*> (sc))
68 m = m >? st->beam_count (LEFT) >? st->beam_count (RIGHT);
74 After pre-processing all directions should be set.
75 Several post-processing routines (stem, slur, script) need stem/beam
77 Currenly, this means that beam has set all stem's directions.
78 [Alternatively, stems could set its own directions, according to
79 their beam, during 'final-pre-processing'.]
82 Beam::before_line_breaking ()
85 if (visible_stem_count () < 2)
87 warning (_ ("beam has less than two stems"));
88 // set_elt_property ("transparent", SCM_BOOL_T);
91 if (!directional_element (this).get ())
92 directional_element (this).set (get_default_dir ());
95 set_stem_directions ();
103 Beam::get_default_dir () const
105 Drul_array<int> total;
106 total[UP] = total[DOWN] = 0;
107 Drul_array<int> count;
108 count[UP] = count[DOWN] = 0;
111 for (int i=0; i <stem_count (); i++)
112 do { // HUH -- waar slaat dit op?
114 Direction sd = directional_element (s).get ();
115 int current = sd ? (1 + d * sd)/2
116 : s->get_center_distance ((Direction)-d);
124 } while (flip(&d) != DOWN);
127 SCM s = scm_eval (gh_list (ly_symbol2scm ("beam-dir-algorithm"),
128 ly_quote_scm (gh_cons (gh_int2scm (count[UP]),
129 gh_int2scm (count[DOWN]))),
130 ly_quote_scm (gh_cons (gh_int2scm (total[UP]),
131 gh_int2scm (total[DOWN]))),
133 if (gh_number_p (s) && gh_scm2int (s))
137 If dir is not determined: get from paper
139 return (Direction)(int)
140 paper_l ()->get_var ("stem_default_neutral_direction");
145 Set all stems with non-forced direction to beam direction.
146 Urg: non-forced should become `without/with unforced' direction,
147 once stem gets cleaned-up.
150 Beam::set_stem_directions ()
152 Direction d = directional_element (this).get ();
153 for (int i=0; i <stem_count (); i++)
156 SCM force = s->remove_elt_property ("dir-forced");
157 if (!gh_boolean_p (force) || !gh_scm2bool (force))
158 directional_element (s).set (d);
165 if (!auto_knee ("auto-interstaff-knee-gap", true))
166 auto_knee ("auto-knee-gap", false);
170 Simplistic auto-knees; only consider vertical gap between two
173 `Forced' stem directions are ignored. If you don't want auto-knees,
174 don't set, or unset autoKneeGap/autoInterstaffKneeGap.
177 Beam::auto_knee (String gap_str, bool interstaff_b)
181 SCM gap = get_elt_property (gap_str);
182 Direction d = directional_element (this).get ();
184 if (gh_number_p (gap))
186 int auto_gap_i = gh_scm2int (gap);
187 for (int i=1; i < stem_count (); i++)
189 bool is_b = (bool)(calc_interstaff_dist (stem (i), this)
190 - calc_interstaff_dist (stem (i-1), this));
191 int l_y = (int)(stem (i-1)->head_positions()[d])
192 + (int)calc_interstaff_dist (stem (i-1), this);
193 int r_y = (int)(stem (i)->head_positions()[d])
194 + (int)calc_interstaff_dist (stem (i), this);
195 int gap_i = r_y - l_y;
197 if ((abs (gap_i) >= auto_gap_i) && (!interstaff_b || is_b))
199 knee_y = (r_y + l_y) / 2;
207 for (int i=0; i < stem_count (); i++)
209 int y = (int)(stem (i)->head_positions()[d])
210 + (int)calc_interstaff_dist (stem (i), this);
211 directional_element (stem (i)).set (y < knee_y ? UP : DOWN);
212 stem (i)->set_elt_property ("dir-forced", SCM_BOOL_T);
219 Set stem's shorten property if unset.
221 take some y-position (chord/beam/nearest?) into account
222 scmify forced-fraction
225 Beam::set_stem_shorten ()
227 if (!visible_stem_count ())
230 Real forced_fraction = forced_stem_count () / visible_stem_count ();
231 if (forced_fraction < 0.5)
234 int multiplicity = get_multiplicity ();
236 SCM shorten = ly_eval_str ("beamed-stem-shorten");
239 scm_to_array (shorten, &a);
243 Staff_symbol_referencer_interface st (this);
244 Real staff_space = st.staff_space ();
245 Real shorten_f = a[multiplicity <? (a.size () - 1)] * staff_space;
247 /* cute, but who invented this -- how to customise ? */
248 if (forced_fraction < 1)
251 for (int i=0; i < stem_count (); i++)
254 if (s->invisible_b ())
256 if (gh_number_p (s->get_elt_property ("shorten")))
257 s->set_elt_property ("shorten", gh_double2scm (shorten_f));
262 Set elt properties height and y-position if not set.
263 Adjust stem lengths to reach beam.
266 Beam::after_line_breaking ()
268 /* first, calculate y, dy */
270 calc_position_and_height (&y, &dy);
271 if (visible_stem_count ())
273 if (suspect_slope_b (y, dy))
276 Real damped_dy = calc_slope_damping_f (dy);
277 Real quantised_dy = quantise_dy_f (damped_dy);
279 y += (dy - quantised_dy) / 2;
283 until here, we used only stem_info, which acts as if dir=up
285 y *= directional_element (this).get ();
286 dy *= directional_element (this).get ();
288 Staff_symbol_referencer_interface st (this);
289 Real half_space = st.staff_space () / 2;
291 /* check for user-override of dy */
292 SCM s = remove_elt_property ("height-hs");
295 dy = gh_scm2double (s) * half_space;
297 set_elt_property ("height", gh_double2scm (dy));
299 /* check for user-override of y */
300 s = remove_elt_property ("y-position-hs");
303 y = gh_scm2double (s) * half_space;
307 /* we can modify y, so we should quantise y */
308 Real y_shift = check_stem_length_f (y, dy);
310 y = quantise_y_f (y, dy, 0);
311 set_stem_length (y, dy);
312 y_shift = check_stem_length_f (y, dy);
314 if (y_shift > half_space / 4)
319 for significantly lengthened or shortened stems,
320 request quanting the other way.
323 if (abs (y_shift) > half_space / 2)
324 quant_dir = sign (y_shift) * directional_element (this).get ();
325 y = quantise_y_f (y, dy, quant_dir);
328 // UGH. Y is not in staff position unit?
329 // Ik dacht datwe daar juist van weg wilden?
330 set_stem_length (y, dy);
331 set_elt_property ("y-position", gh_double2scm (y));
335 See Documentation/tex/fonts.doc
338 Beam::calc_position_and_height (Real* y, Real* dy) const
341 if (visible_stem_count () <= 1)
344 Real first_ideal = first_visible_stem ()->calc_stem_info ().idealy_f_;
345 if (first_ideal == last_visible_stem ()->calc_stem_info ().idealy_f_)
352 Array<Offset> ideals;
353 Real x0 = first_visible_stem ()->relative_coordinate (0, X_AXIS);
354 for (int i=0; i < stem_count (); i++)
357 if (s->invisible_b ())
359 ideals.push (Offset (s->relative_coordinate (0, X_AXIS) - x0,
360 s->calc_stem_info ().idealy_f_));
363 minimise_least_squares (&dydx, y, ideals); // duh, takes references
365 Real dx = last_visible_stem ()->relative_coordinate (0, X_AXIS) - x0;
370 Beam::suspect_slope_b (Real y, Real dy) const
372 /* first, calculate y, dy */
374 steep slope running against lengthened stem is suspect
376 Real first_ideal = first_visible_stem ()->calc_stem_info ().idealy_f_;
377 Real last_ideal = last_visible_stem ()->calc_stem_info ().idealy_f_;
378 Real lengthened = paper_l ()->get_var ("beam_lengthened");
379 Real steep = paper_l ()->get_var ("beam_steep_slope");
381 Real dx = last_visible_stem ()->relative_coordinate (0, X_AXIS) - first_visible_stem ()->relative_coordinate (0, X_AXIS);
382 Real dydx = dy && dx ? dy/dx : 0;
384 if (((y - first_ideal > lengthened) && (dydx > steep))
385 || ((y + dy - last_ideal > lengthened) && (dydx < -steep)))
393 This neat trick is by Werner Lemberg,
394 damped = tanh (slope)
395 corresponds with some tables in [Wanske]
398 Beam::calc_slope_damping_f (Real dy) const
400 SCM damp = get_elt_property ("damping"); // remove?
401 int damping = 1; // ugh.
402 if (gh_number_p (damp))
403 damping = gh_scm2int (damp);
407 Real dx = last_visible_stem ()->relative_coordinate (0, X_AXIS)
408 - first_visible_stem ()->relative_coordinate (0, X_AXIS);
409 Real dydx = dy && dx ? dy/dx : 0;
410 dydx = 0.6 * tanh (dydx) / damping;
417 Beam::calc_stem_y_f (Stem* s, Real y, Real dy) const
419 Real thick = gh_scm2double (get_elt_property ("beam-thickness"));
420 int beam_multiplicity = get_multiplicity ();
421 int stem_multiplicity = (s->flag_i () - 2) >? 0;
423 Real interbeam_f = paper_l ()->interbeam_f (beam_multiplicity);
424 Real x0 = first_visible_stem ()->relative_coordinate (0, X_AXIS);
425 Real dx = last_visible_stem ()->relative_coordinate (0, X_AXIS) - x0;
426 Real stem_y = (dy && dx ? (s->relative_coordinate (0, X_AXIS) - x0) / dx * dy : 0) + y;
429 Direction dir = directional_element(this).get ();
430 Direction sdir = directional_element (s).get ();
436 * (thick / 2 + (beam_multiplicity - 1) * interbeam_f);
438 Staff_symbol_referencer_interface me (s);
439 Staff_symbol_referencer_interface last (last_visible_stem ());
441 // huh, why not for first visible?
442 if (//(s != first_visible_stem ()) &&
443 me.staff_symbol_l () != last.staff_symbol_l ())
444 stem_y += directional_element (this).get ()
445 * (beam_multiplicity - stem_multiplicity) * interbeam_f;
451 Beam::check_stem_length_f (Real y, Real dy) const
455 Direction dir = directional_element (this).get ();
457 for (int i=0; i < stem_count (); i++)
460 if (s->invisible_b ())
463 Real stem_y = calc_stem_y_f (s, y, dy);
466 Stem_info info = s->calc_stem_info ();
468 // if (0 > info.maxy_f_ - stem_y)
469 shorten = shorten <? info.maxy_f_ - stem_y;
470 // if (0 < info.miny_f_ - stem_y)
471 lengthen = lengthen >? info.miny_f_ - stem_y;
474 if (lengthen && shorten)
475 warning (_ ("weird beam vertical offset"));
477 /* when all stems are too short, normal stems win */
478 return dir * ((shorten) ? shorten : lengthen);
482 Hmm. At this time, beam position and slope are determined. Maybe,
483 stem directions and length should set to relative to the chord's
484 position of the beam. */
486 Beam::set_stem_length (Real y, Real dy)
488 Staff_symbol_referencer_interface st (this);
489 Real half_space = st.staff_space ()/2;
490 for (int i=0; i < stem_count (); i++)
493 if (s->invisible_b ())
496 Real stem_y = calc_stem_y_f (s, y, dy);
498 /* caution: stem measures in staff-positions */
499 s->set_stemend ((stem_y + calc_interstaff_dist (s, this)) / half_space);
504 [Ross] (simplification of)
505 Set dy complying with:
507 - thick / 2 + staffline_f / 2
508 - thick + staffline_f
512 Beam::quantise_dy_f (Real dy) const
514 SCM quants = ly_eval_str ("beam-height-quants");
517 scm_to_array (quants, &a);
521 Staff_symbol_referencer_interface st (this);
522 Real staff_space = st.staff_space ();
524 Interval iv = quantise_iv (a, abs (dy)/staff_space) * staff_space;
525 Real q = (abs (dy) - iv[SMALLER] <= iv[BIGGER] - abs (dy))
529 return q * sign (dy);
533 Prevent interference from stafflines and beams.
534 See Documentation/tex/fonts.doc
536 We only need to quantise the (left) y-position of the beam,
537 since dy is quantised too.
538 if extend_b then stems must *not* get shorter
541 Beam::quantise_y_f (Real y, Real dy, int quant_dir)
543 int multiplicity = get_multiplicity ();
544 Staff_symbol_referencer_interface st (this);
545 Real staff_space = st.staff_space ();
546 SCM quants = scm_eval (gh_list (
547 ly_symbol2scm ("beam-vertical-position-quants"),
548 gh_int2scm (multiplicity),
549 gh_double2scm (dy/staff_space),
552 scm_to_array (quants, &a);
556 Real up_y = directional_element (this).get () * y;
557 Interval iv = quantise_iv (a, up_y/staff_space) * staff_space;
559 Real q = up_y - iv[SMALLER] <= iv[BIGGER] - up_y
560 ? iv[SMALLER] : iv[BIGGER];
562 q = iv[(Direction)quant_dir];
564 return q * directional_element (this).get ();
568 Beam::set_beaming (Beaming_info_list *beaming)
571 for (int i=0; i < stem_count (); i++)
575 if (stem (i)->beam_count (d) == 0)
576 stem (i)->set_beaming ( beaming->infos_.elem (i).beams_i_drul_[d],d);
578 while (flip (&d) != LEFT);
585 beams to go with one stem.
591 Beam::stem_beams (Stem *here, Stem *next, Stem *prev) const
593 if ((next && !(next->relative_coordinate (0, X_AXIS) > here->relative_coordinate (0, X_AXIS))) ||
594 (prev && !(prev->relative_coordinate (0, X_AXIS) < here->relative_coordinate (0, X_AXIS))))
595 programming_error ("Beams are not left-to-right");
597 Real staffline_f = paper_l ()->get_var ("stafflinethickness");
598 int multiplicity = get_multiplicity ();
601 Real interbeam_f = paper_l ()->interbeam_f (multiplicity);
602 Real thick = gh_scm2double (get_elt_property ("beam-thickness"));
604 Real bdy = interbeam_f;
605 Real stemdx = staffline_f;
607 Real dx = visible_stem_count () ?
608 last_visible_stem ()->relative_coordinate (0, X_AXIS) - first_visible_stem ()->relative_coordinate (0, X_AXIS)
610 Real dy = gh_scm2double (get_elt_property ("height"));
611 Real dydx = dy && dx ? dy/dx : 0;
618 if (!here->first_head ())
620 else if (here->type_i ()== 1)
621 nw_f = paper_l ()->get_var ("wholewidth");
622 else if (here->type_i () == 2)
623 nw_f = paper_l ()->get_var ("notewidth") * 0.8;
625 nw_f = paper_l ()->get_var ("quartwidth");
628 Direction dir = directional_element (this).get ();
630 /* half beams extending to the left. */
633 int lhalfs= lhalfs = here->beam_count (LEFT) - prev->beam_count (RIGHT);
634 int lwholebeams= here->beam_count (LEFT) <? prev->beam_count (RIGHT) ;
636 Half beam should be one note-width,
637 but let's make sure two half-beams never touch
639 Real w = here->relative_coordinate (0, X_AXIS) - prev->relative_coordinate (0, X_AXIS);
642 if (lhalfs) // generates warnings if not
643 a = lookup_l ()->beam (dydx, w, thick);
644 a.translate (Offset (-w, -w * dydx));
645 for (int j = 0; j < lhalfs; j++)
648 b.translate_axis (-dir * bdy * (lwholebeams+j), Y_AXIS);
649 leftbeams.add_molecule (b);
655 int rhalfs = here->beam_count (RIGHT) - next->beam_count (LEFT);
656 int rwholebeams= here->beam_count (RIGHT) <? next->beam_count (LEFT) ;
658 Real w = next->relative_coordinate (0, X_AXIS) - here->relative_coordinate (0, X_AXIS);
659 Molecule a = lookup_l ()->beam (dydx, w + stemdx, thick);
660 a.translate_axis( - stemdx/2, X_AXIS);
664 SCM gap = get_elt_property ("beam-gap");
665 if (gh_number_p (gap))
667 int gap_i = gh_scm2int ( (gap));
668 int nogap = rwholebeams - gap_i;
670 for (; j < nogap; j++)
673 b.translate_axis (-dir * bdy * j, Y_AXIS);
674 rightbeams.add_molecule (b);
676 // TODO: notehead widths differ for different types
679 a = lookup_l ()->beam (dydx, w + stemdx, thick);
682 for (; j < rwholebeams; j++)
685 b.translate (Offset (here->invisible_b () ? 0 : gap_f, -dir * bdy * j));
686 rightbeams.add_molecule (b);
691 a = lookup_l ()->beam (dydx, w, thick);
693 for (; j < rwholebeams + rhalfs; j++)
696 b.translate_axis (- dir * bdy * j, Y_AXIS);
697 rightbeams.add_molecule (b);
701 leftbeams.add_molecule (rightbeams);
704 Does beam quanting think of the asymetry of beams?
705 Refpoint is on bottom of symbol. (FIXTHAT) --hwn.
712 Beam::do_brew_molecule () const
718 if (visible_stem_count ())
720 x0 = first_visible_stem ()->relative_coordinate (0, X_AXIS);
721 dx = last_visible_stem ()->relative_coordinate (0, X_AXIS) - x0;
725 x0 = stem (0)->relative_coordinate (0, X_AXIS);
726 dx = stem_top ()->relative_coordinate (0, X_AXIS) - x0;
730 Real dy = gh_scm2double (get_elt_property ("height"));
731 Real dydx = dy && dx ? dy/dx : 0;
732 Real y = gh_scm2double (get_elt_property ("y-position"));
733 for (int j=0; j <stem_count (); j++)
736 Stem * prev = (j > 0)? stem (j-1) : 0;
737 Stem * next = (j < stem_count ()-1) ? stem (j+1) :0;
739 Molecule sb = stem_beams (i, next, prev);
740 Real x = i->relative_coordinate (0, X_AXIS)-x0;
741 sb.translate (Offset (x, x * dydx + y));
742 mol.add_molecule (sb);
744 mol.translate_axis (x0
745 - get_bound (LEFT)->relative_coordinate (0, X_AXIS), X_AXIS);
751 Beam::forced_stem_count () const
754 for (int i=0; i < stem_count (); i++)
758 if (s->invisible_b ())
761 if (((int)s->chord_start_f ())
762 && (s->get_direction () != s->get_default_dir ()))
771 TODO: Fix this class. This is wildly inefficient.
772 And it sux. Yet another array/list 'interface'.
775 Beam::stem (int i) const
777 return Group_interface__extract_elements ((Beam*) this, (Stem*) 0, "stems")[i];
781 Beam::stem_count () const
783 Group_interface gi (this, "stems");
788 Beam::stem_top () const
790 SCM s = get_elt_property ("stems");
792 return gh_pair_p (s) ? dynamic_cast<Stem*> (unsmob_element (gh_car (s))) : 0;
794 //Group_interface__extract_elements ((Beam*) this, (Stem*) 0, "stems")[stem_count () - 1];
799 Beam::visible_stem_count () const
802 for (int i = 0; i < stem_count (); i++)
804 if (!stem (i)->invisible_b ())
811 Beam::first_visible_stem () const
813 for (int i = 0; i < stem_count (); i++)
816 if (!s->invisible_b ())
823 Beam::last_visible_stem () const
825 for (int i = stem_count (); i > 0; i--)
827 Stem* s = stem (i - 1);
828 if (!s->invisible_b ())