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 staff_space = st.staff_space ();
290 /* check for user-override of dy */
291 SCM s = remove_elt_property ("Height");
294 dy = gh_scm2double (s) * staff_space;
296 set_elt_property ("height", gh_double2scm (dy));
298 /* check for user-override of y */
299 s = remove_elt_property ("verticalPosition");
302 y = gh_scm2double (s) * staff_space;
303 set_stem_length (y, dy);
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 Real half_space = st.staff_space () / 2;
315 if (y_shift > half_space / 4)
320 for significantly lengthened or shortened stems,
321 request quanting the other way.
324 if (abs (y_shift) > half_space / 2)
325 quant_dir = sign (y_shift) * directional_element (this).get ();
326 y = quantise_y_f (y, dy, quant_dir);
327 set_stem_length (y, dy);
330 // UGH. Y is not in staff position unit?
331 // Ik dacht datwe daar juist van weg wilden?
332 set_elt_property ("y-position", gh_double2scm (y));
336 See Documentation/tex/fonts.doc
339 Beam::calc_position_and_height (Real* y, Real* dy) const
342 if (visible_stem_count () <= 1)
345 Real first_ideal = first_visible_stem ()->calc_stem_info ().idealy_f_;
346 if (first_ideal == last_visible_stem ()->calc_stem_info ().idealy_f_)
353 Array<Offset> ideals;
354 Real x0 = first_visible_stem ()->hpos_f ();
355 for (int i=0; i < stem_count (); i++)
358 if (s->invisible_b ())
360 ideals.push (Offset (s->hpos_f () - x0,
361 s->calc_stem_info ().idealy_f_));
364 minimise_least_squares (&dydx, y, ideals); // duh, takes references
366 Real dx = last_visible_stem ()->hpos_f () - x0;
371 Beam::suspect_slope_b (Real y, Real dy) const
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 ()->hpos_f () - first_visible_stem ()->hpos_f ();
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 ()->hpos_f ()
408 - first_visible_stem ()->hpos_f ();
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 ()->hpos_f ();
425 Real dx = last_visible_stem ()->hpos_f () - x0;
426 Real stem_y = (dy && dx ? (s->hpos_f () - 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->hpos_f () > here->hpos_f ())) ||
594 (prev && !(prev->hpos_f () < here->hpos_f ())))
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 = last_visible_stem ()->hpos_f () - first_visible_stem ()->hpos_f ();
608 Real dy = get_real ("height");
609 Real dydx = dy && dx ? dy/dx : 0;
616 if (!here->first_head ())
618 else if (here->type_i ()== 1)
619 nw_f = paper_l ()->get_var ("wholewidth");
620 else if (here->type_i () == 2)
621 nw_f = paper_l ()->get_var ("notewidth") * 0.8;
623 nw_f = paper_l ()->get_var ("quartwidth");
626 Direction dir = directional_element (this).get ();
628 /* half beams extending to the left. */
631 int lhalfs= lhalfs = here->beam_count (LEFT) - prev->beam_count (RIGHT);
632 int lwholebeams= here->beam_count (LEFT) <? prev->beam_count (RIGHT) ;
634 Half beam should be one note-width,
635 but let's make sure two half-beams never touch
637 Real w = here->hpos_f () - prev->hpos_f ();
640 if (lhalfs) // generates warnings if not
641 a = lookup_l ()->beam (dydx, w, thick);
642 a.translate (Offset (-w, -w * dydx));
643 for (int j = 0; j < lhalfs; j++)
646 b.translate_axis (-dir * bdy * (lwholebeams+j), Y_AXIS);
647 leftbeams.add_molecule (b);
653 int rhalfs = here->beam_count (RIGHT) - next->beam_count (LEFT);
654 int rwholebeams= here->beam_count (RIGHT) <? next->beam_count (LEFT) ;
656 Real w = next->hpos_f () - here->hpos_f ();
657 Molecule a = lookup_l ()->beam (dydx, w + stemdx, thick);
658 a.translate_axis( - stemdx/2, X_AXIS);
662 SCM gap = get_elt_property ("beam-gap");
663 if (gh_number_p (gap))
665 int gap_i = gh_scm2int ( (gap));
666 int nogap = rwholebeams - gap_i;
668 for (; j < nogap; j++)
671 b.translate_axis (-dir * bdy * j, Y_AXIS);
672 rightbeams.add_molecule (b);
674 // TODO: notehead widths differ for different types
677 a = lookup_l ()->beam (dydx, w + stemdx, thick);
680 for (; j < rwholebeams; j++)
683 b.translate (Offset (here->invisible_b () ? 0 : gap_f, -dir * bdy * j));
684 rightbeams.add_molecule (b);
689 a = lookup_l ()->beam (dydx, w, thick);
691 for (; j < rwholebeams + rhalfs; j++)
694 b.translate_axis (- dir * bdy * j, Y_AXIS);
695 rightbeams.add_molecule (b);
699 leftbeams.add_molecule (rightbeams);
702 Does beam quanting think of the asymetry of beams?
703 Refpoint is on bottom of symbol. (FIXTHAT) --hwn.
710 Beam::do_brew_molecule_p () const
712 Molecule *mol_p = new Molecule;
716 Real x0 = first_visible_stem ()->hpos_f ();
717 Real dx = last_visible_stem ()->hpos_f () - x0;
718 Real dy = get_real ("height");
719 Real dydx = dy && dx ? dy/dx : 0;
720 Real y = get_real ("y-position");
721 for (int j=0; j <stem_count (); j++)
724 Stem * prev = (j > 0)? stem (j-1) : 0;
725 Stem * next = (j < stem_count ()-1) ? stem (j+1) :0;
727 Molecule sb = stem_beams (i, next, prev);
728 Real x = i->hpos_f ()-x0;
729 sb.translate (Offset (x, x * dydx + y));
730 mol_p->add_molecule (sb);
732 mol_p->translate_axis (x0
733 - spanned_drul_[LEFT]->relative_coordinate (0, X_AXIS), X_AXIS);
739 Beam::forced_stem_count () const
742 for (int i=0; i < stem_count (); i++)
746 if (s->invisible_b ())
749 if (((int)s->chord_start_f ())
750 && (s->get_direction () != s->get_default_dir ()))
759 TODO: Fix this class. This is wildly inefficient.
760 And it sux. Yet another array/list 'interface'.
763 Beam::stem (int i) const
765 return Group_interface__extract_elements ((Beam*) this, (Stem*) 0, "stems")[i];
769 Beam::stem_count () const
771 Group_interface gi (this, "stems");
776 Beam::stem_top () const
778 SCM s = get_elt_property ("stems");
780 return gh_pair_p (s) ? dynamic_cast<Stem*> (unsmob_element (gh_car (s))) : 0;
782 //Group_interface__extract_elements ((Beam*) this, (Stem*) 0, "stems")[stem_count () - 1];
787 Beam::visible_stem_count () const
790 for (int i = 0; i < stem_count (); i++)
792 if (!stem (i)->invisible_b ())
799 Beam::first_visible_stem () const
801 for (int i = 0; i < stem_count (); i++)
804 if (!s->invisible_b ())
814 Beam::last_visible_stem () const
816 for (int i = stem_count (); i > 0; i--)
818 Stem* s = stem (i - 1);
819 if (!s->invisible_b ())