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 (!spanned_drul_[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::do_pre_processing ()
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 ();
104 Beam::get_default_dir () const
106 Drul_array<int> total;
107 total[UP] = total[DOWN] = 0;
108 Drul_array<int> count;
109 count[UP] = count[DOWN] = 0;
112 for (int i=0; i <stem_count (); i++)
113 do { // HUH -- waar slaat dit op?
115 Direction sd = directional_element (s).get ();
116 int current = sd ? (1 + d * sd)/2
117 : s->get_center_distance ((Direction)-d);
125 } while (flip(&d) != DOWN);
128 SCM s = scm_eval (gh_list (ly_symbol2scm ("beam-dir-algorithm"),
129 ly_quote_scm (gh_cons (gh_int2scm (count[UP]),
130 gh_int2scm (count[DOWN]))),
131 ly_quote_scm (gh_cons (gh_int2scm (total[UP]),
132 gh_int2scm (total[DOWN]))),
134 if (gh_number_p (s) && gh_scm2int (s))
138 If dir is not determined: get from paper
140 return (Direction)(int)
141 paper_l ()->get_var ("stem_default_neutral_direction");
146 Set all stems with non-forced direction to beam direction.
147 Urg: non-forced should become `without/with unforced' direction,
148 once stem gets cleaned-up.
151 Beam::set_stem_directions ()
153 Direction d = directional_element (this).get ();
154 for (int i=0; i <stem_count (); i++)
157 SCM force = s->remove_elt_property ("dir-forced");
158 if (!gh_boolean_p (force) || !gh_scm2bool (force))
159 directional_element (s).set (d);
166 if (!auto_knee ("auto-interstaff-knee-gap", true))
167 auto_knee ("auto-knee-gap", false);
171 Simplistic auto-knees; only consider vertical gap between two
174 `Forced' stem directions are ignored. If you don't want auto-knees,
175 don't set, or unset autoKneeGap/autoInterstaffKneeGap.
178 Beam::auto_knee (String gap_str, bool interstaff_b)
182 SCM gap = get_elt_property (gap_str);
183 Direction d = directional_element (this).get ();
185 if (gh_number_p (gap))
187 int auto_gap_i = gh_scm2int (gap);
188 for (int i=1; i < stem_count (); i++)
190 bool is_b = (bool)(calc_interstaff_dist (stem (i), this)
191 - calc_interstaff_dist (stem (i-1), this));
192 int l_y = (int)(stem (i-1)->head_positions()[d])
193 + (int)calc_interstaff_dist (stem (i-1), this);
194 int r_y = (int)(stem (i)->head_positions()[d])
195 + (int)calc_interstaff_dist (stem (i), this);
196 int gap_i = r_y - l_y;
198 if ((abs (gap_i) >= auto_gap_i) && (!interstaff_b || is_b))
200 knee_y = (r_y + l_y) / 2;
208 for (int i=0; i < stem_count (); i++)
210 int y = (int)(stem (i)->head_positions()[d])
211 + (int)calc_interstaff_dist (stem (i), this);
212 directional_element (stem (i)).set (y < knee_y ? UP : DOWN);
213 stem (i)->set_elt_property ("dir-forced", SCM_BOOL_T);
220 Set stem's shorten property if unset.
222 take some y-position (chord/beam/nearest?) into account
223 scmify forced-fraction
226 Beam::set_stem_shorten ()
228 if (!visible_stem_count ())
231 Real forced_fraction = forced_stem_count () / visible_stem_count ();
232 if (forced_fraction < 0.5)
235 int multiplicity = get_multiplicity ();
237 SCM shorten = ly_eval_str ("beamed-stem-shorten");
240 scm_to_array (shorten, &a);
244 Staff_symbol_referencer_interface st (this);
245 Real staff_space = st.staff_space ();
246 Real shorten_f = a[multiplicity <? (a.size () - 1)] * staff_space;
248 /* cute, but who invented this -- how to customise ? */
249 if (forced_fraction < 1)
252 for (int i=0; i < stem_count (); i++)
255 if (s->invisible_b ())
257 if (gh_number_p (s->get_elt_property ("shorten")))
258 s->set_elt_property ("shorten", gh_double2scm (shorten_f));
263 Set elt properties height and y-position if not set.
264 Adjust stem lengths to reach beam.
267 Beam::do_post_processing ()
269 /* first, calculate y, dy */
271 calc_position_and_height (&y, &dy);
272 if (suspect_slope_b (y, dy))
275 Real damped_dy = calc_slope_damping_f (dy);
276 Real quantised_dy = quantise_dy_f (damped_dy);
278 y += (dy - quantised_dy) / 2;
282 until here, we used only stem_info, which acts as if dir=up
284 y *= directional_element (this).get ();
285 dy *= directional_element (this).get ();
287 Staff_symbol_referencer_interface st (this);
288 Real half_space = st.staff_space () / 2;
290 /* check for user-override of dy */
291 SCM s = remove_elt_property ("height-hs");
294 dy = gh_scm2double (s) * half_space;
296 set_elt_property ("height", gh_double2scm (dy));
298 /* check for user-override of y */
299 s = remove_elt_property ("y-position-hs");
302 y = gh_scm2double (s) * half_space;
306 /* we can modify y, so we should quantise y */
307 Real y_shift = check_stem_length_f (y, dy);
309 y = quantise_y_f (y, dy, 0);
310 set_stem_length (y, dy);
311 y_shift = check_stem_length_f (y, dy);
313 if (y_shift > half_space / 4)
318 for significantly lengthened or shortened stems,
319 request quanting the other way.
322 if (abs (y_shift) > half_space / 2)
323 quant_dir = sign (y_shift) * directional_element (this).get ();
324 y = quantise_y_f (y, dy, quant_dir);
327 // UGH. Y is not in staff position unit?
328 // Ik dacht datwe daar juist van weg wilden?
329 set_stem_length (y, dy);
330 set_elt_property ("y-position", gh_double2scm (y));
334 See Documentation/tex/fonts.doc
337 Beam::calc_position_and_height (Real* y, Real* dy) const
340 if (visible_stem_count () <= 1)
343 Real first_ideal = first_visible_stem ()->calc_stem_info ().idealy_f_;
344 if (first_ideal == last_visible_stem ()->calc_stem_info ().idealy_f_)
351 Array<Offset> ideals;
352 Real x0 = first_visible_stem ()->hpos_f ();
353 for (int i=0; i < stem_count (); i++)
356 if (s->invisible_b ())
358 ideals.push (Offset (s->hpos_f () - x0,
359 s->calc_stem_info ().idealy_f_));
362 minimise_least_squares (&dydx, y, ideals); // duh, takes references
364 Real dx = last_visible_stem ()->hpos_f () - x0;
369 Beam::suspect_slope_b (Real y, Real dy) const
372 steep slope running against lengthened stem is suspect
374 Real first_ideal = first_visible_stem ()->calc_stem_info ().idealy_f_;
375 Real last_ideal = last_visible_stem ()->calc_stem_info ().idealy_f_;
376 Real lengthened = paper_l ()->get_var ("beam_lengthened");
377 Real steep = paper_l ()->get_var ("beam_steep_slope");
379 Real dx = last_visible_stem ()->hpos_f () - first_visible_stem ()->hpos_f ();
380 Real dydx = dy && dx ? dy/dx : 0;
382 if (((y - first_ideal > lengthened) && (dydx > steep))
383 || ((y + dy - last_ideal > lengthened) && (dydx < -steep)))
391 This neat trick is by Werner Lemberg,
392 damped = tanh (slope)
393 corresponds with some tables in [Wanske]
396 Beam::calc_slope_damping_f (Real dy) const
398 SCM damp = get_elt_property ("damping"); // remove?
399 int damping = 1; // ugh.
400 if (gh_number_p (damp))
401 damping = gh_scm2int (damp);
405 Real dx = last_visible_stem ()->hpos_f ()
406 - first_visible_stem ()->hpos_f ();
407 Real dydx = dy && dx ? dy/dx : 0;
408 dydx = 0.6 * tanh (dydx) / damping;
415 Beam::calc_stem_y_f (Stem* s, Real y, Real dy) const
417 Real thick = gh_scm2double (get_elt_property ("beam-thickness"));
418 int beam_multiplicity = get_multiplicity ();
419 int stem_multiplicity = (s->flag_i () - 2) >? 0;
421 Real interbeam_f = paper_l ()->interbeam_f (beam_multiplicity);
422 Real x0 = first_visible_stem ()->hpos_f ();
423 Real dx = last_visible_stem ()->hpos_f () - x0;
424 Real stem_y = (dy && dx ? (s->hpos_f () - x0) / dx * dy : 0) + y;
427 Direction dir = directional_element(this).get ();
428 Direction sdir = directional_element (s).get ();
434 * (thick / 2 + (beam_multiplicity - 1) * interbeam_f);
436 Staff_symbol_referencer_interface me (s);
437 Staff_symbol_referencer_interface last (last_visible_stem ());
439 // huh, why not for first visible?
440 if (//(s != first_visible_stem ()) &&
441 me.staff_symbol_l () != last.staff_symbol_l ())
442 stem_y += directional_element (this).get ()
443 * (beam_multiplicity - stem_multiplicity) * interbeam_f;
449 Beam::check_stem_length_f (Real y, Real dy) const
453 Direction dir = directional_element (this).get ();
455 for (int i=0; i < stem_count (); i++)
458 if (s->invisible_b ())
461 Real stem_y = calc_stem_y_f (s, y, dy);
464 Stem_info info = s->calc_stem_info ();
466 // if (0 > info.maxy_f_ - stem_y)
467 shorten = shorten <? info.maxy_f_ - stem_y;
468 // if (0 < info.miny_f_ - stem_y)
469 lengthen = lengthen >? info.miny_f_ - stem_y;
472 if (lengthen && shorten)
473 warning (_ ("weird beam vertical offset"));
475 /* when all stems are too short, normal stems win */
476 return dir * ((shorten) ? shorten : lengthen);
480 Hmm. At this time, beam position and slope are determined. Maybe,
481 stem directions and length should set to relative to the chord's
482 position of the beam. */
484 Beam::set_stem_length (Real y, Real dy)
486 Staff_symbol_referencer_interface st (this);
487 Real half_space = st.staff_space ()/2;
488 for (int i=0; i < stem_count (); i++)
491 if (s->invisible_b ())
494 Real stem_y = calc_stem_y_f (s, y, dy);
496 /* caution: stem measures in staff-positions */
497 s->set_stemend ((stem_y + calc_interstaff_dist (s, this)) / half_space);
502 [Ross] (simplification of)
503 Set dy complying with:
505 - thick / 2 + staffline_f / 2
506 - thick + staffline_f
510 Beam::quantise_dy_f (Real dy) const
512 SCM quants = ly_eval_str ("beam-height-quants");
515 scm_to_array (quants, &a);
519 Staff_symbol_referencer_interface st (this);
520 Real staff_space = st.staff_space ();
522 Interval iv = quantise_iv (a, abs (dy)/staff_space) * staff_space;
523 Real q = (abs (dy) - iv[SMALLER] <= iv[BIGGER] - abs (dy))
527 return q * sign (dy);
531 Prevent interference from stafflines and beams.
532 See Documentation/tex/fonts.doc
534 We only need to quantise the (left) y-position of the beam,
535 since dy is quantised too.
536 if extend_b then stems must *not* get shorter
539 Beam::quantise_y_f (Real y, Real dy, int quant_dir)
541 int multiplicity = get_multiplicity ();
542 Staff_symbol_referencer_interface st (this);
543 Real staff_space = st.staff_space ();
544 SCM quants = scm_eval (gh_list (
545 ly_symbol2scm ("beam-vertical-position-quants"),
546 gh_int2scm (multiplicity),
547 gh_double2scm (dy/staff_space),
550 scm_to_array (quants, &a);
554 Real up_y = directional_element (this).get () * y;
555 Interval iv = quantise_iv (a, up_y/staff_space) * staff_space;
557 Real q = up_y - iv[SMALLER] <= iv[BIGGER] - up_y
558 ? iv[SMALLER] : iv[BIGGER];
560 q = iv[(Direction)quant_dir];
562 return q * directional_element (this).get ();
566 Beam::set_beaming (Beaming_info_list *beaming)
569 for (int i=0; i < stem_count (); i++)
573 if (stem (i)->beam_count (d) == 0)
574 stem (i)->set_beaming ( beaming->infos_.elem (i).beams_i_drul_[d],d);
576 while (flip (&d) != LEFT);
583 beams to go with one stem.
589 Beam::stem_beams (Stem *here, Stem *next, Stem *prev) const
591 if ((next && !(next->hpos_f () > here->hpos_f ())) ||
592 (prev && !(prev->hpos_f () < here->hpos_f ())))
593 programming_error ("Beams are not left-to-right");
595 Real staffline_f = paper_l ()->get_var ("stafflinethickness");
596 int multiplicity = get_multiplicity ();
599 Real interbeam_f = paper_l ()->interbeam_f (multiplicity);
600 Real thick = gh_scm2double (get_elt_property ("beam-thickness"));;
602 Real bdy = interbeam_f;
603 Real stemdx = staffline_f;
605 Real dx = last_visible_stem ()->hpos_f () - first_visible_stem ()->hpos_f ();
606 Real dy = get_real ("height");
607 Real dydx = dy && dx ? dy/dx : 0;
614 if (!here->first_head ())
616 else if (here->type_i ()== 1)
617 nw_f = paper_l ()->get_var ("wholewidth");
618 else if (here->type_i () == 2)
619 nw_f = paper_l ()->get_var ("notewidth") * 0.8;
621 nw_f = paper_l ()->get_var ("quartwidth");
624 Direction dir = directional_element (this).get ();
626 /* half beams extending to the left. */
629 int lhalfs= lhalfs = here->beam_count (LEFT) - prev->beam_count (RIGHT);
630 int lwholebeams= here->beam_count (LEFT) <? prev->beam_count (RIGHT) ;
632 Half beam should be one note-width,
633 but let's make sure two half-beams never touch
635 Real w = here->hpos_f () - prev->hpos_f ();
638 if (lhalfs) // generates warnings if not
639 a = lookup_l ()->beam (dydx, w, thick);
640 a.translate (Offset (-w, -w * dydx));
641 for (int j = 0; j < lhalfs; j++)
644 b.translate_axis (-dir * bdy * (lwholebeams+j), Y_AXIS);
645 leftbeams.add_molecule (b);
651 int rhalfs = here->beam_count (RIGHT) - next->beam_count (LEFT);
652 int rwholebeams= here->beam_count (RIGHT) <? next->beam_count (LEFT) ;
654 Real w = next->hpos_f () - here->hpos_f ();
655 Molecule a = lookup_l ()->beam (dydx, w + stemdx, thick);
656 a.translate_axis( - stemdx/2, X_AXIS);
660 SCM gap = get_elt_property ("beam-gap");
661 if (gh_number_p (gap))
663 int gap_i = gh_scm2int ( (gap));
664 int nogap = rwholebeams - gap_i;
666 for (; j < nogap; j++)
669 b.translate_axis (-dir * bdy * j, Y_AXIS);
670 rightbeams.add_molecule (b);
672 // TODO: notehead widths differ for different types
675 a = lookup_l ()->beam (dydx, w + stemdx, thick);
678 for (; j < rwholebeams; j++)
681 b.translate (Offset (here->invisible_b () ? 0 : gap_f, -dir * bdy * j));
682 rightbeams.add_molecule (b);
687 a = lookup_l ()->beam (dydx, w, thick);
689 for (; j < rwholebeams + rhalfs; j++)
692 b.translate_axis (- dir * bdy * j, Y_AXIS);
693 rightbeams.add_molecule (b);
697 leftbeams.add_molecule (rightbeams);
700 Does beam quanting think of the asymetry of beams?
701 Refpoint is on bottom of symbol. (FIXTHAT) --hwn.
708 Beam::do_brew_molecule_p () const
710 Molecule *mol_p = new Molecule;
714 Real x0 = first_visible_stem ()->hpos_f ();
715 Real dx = last_visible_stem ()->hpos_f () - x0;
716 Real dy = get_real ("height");
717 Real dydx = dy && dx ? dy/dx : 0;
718 Real y = get_real ("y-position");
719 for (int j=0; j <stem_count (); j++)
722 Stem * prev = (j > 0)? stem (j-1) : 0;
723 Stem * next = (j < stem_count ()-1) ? stem (j+1) :0;
725 Molecule sb = stem_beams (i, next, prev);
726 Real x = i->hpos_f ()-x0;
727 sb.translate (Offset (x, x * dydx + y));
728 mol_p->add_molecule (sb);
730 mol_p->translate_axis (x0
731 - spanned_drul_[LEFT]->relative_coordinate (0, X_AXIS), X_AXIS);
737 Beam::forced_stem_count () const
740 for (int i=0; i < stem_count (); i++)
744 if (s->invisible_b ())
747 if (((int)s->chord_start_f ())
748 && (s->get_direction () != s->get_default_dir ()))
757 TODO: Fix this class. This is wildly inefficient.
758 And it sux. Yet another array/list 'interface'.
761 Beam::stem (int i) const
763 return Group_interface__extract_elements ((Beam*) this, (Stem*) 0, "stems")[i];
767 Beam::stem_count () const
769 Group_interface gi (this, "stems");
774 Beam::stem_top () const
776 SCM s = get_elt_property ("stems");
778 return gh_pair_p (s) ? dynamic_cast<Stem*> (unsmob_element (gh_car (s))) : 0;
780 //Group_interface__extract_elements ((Beam*) this, (Stem*) 0, "stems")[stem_count () - 1];
785 Beam::visible_stem_count () const
788 for (int i = 0; i < stem_count (); i++)
790 if (!stem (i)->invisible_b ())
797 Beam::first_visible_stem () const
799 for (int i = 0; i < stem_count (); i++)
802 if (!s->invisible_b ())
812 Beam::last_visible_stem () const
814 for (int i = stem_count (); i > 0; i--)
816 Stem* s = stem (i - 1);
817 if (!s->invisible_b ())