2 beam.cc -- implement Beam
4 source file of the GNU LilyPond music typesetter
6 (c) 1997 Han-Wen Nienhuys <hanwen@stack.nl>
10 Less hairy code. knee: ([\stem 1; c8 \stem -1; c8]
21 #include "abbreviation-beam.hh"
25 #include "molecule.hh"
26 #include "leastsquares.hh"
28 #include "paper-def.hh"
30 #include "grouping.hh"
31 #include "stem-info.hh"
32 #include "main.hh" // experimental features
35 IMPLEMENT_IS_TYPE_B1 (Beam, Spanner);
38 const int MINIMUM_STEMLEN[] = {
52 quantisation_ = NORMAL;
60 s->add_dependency (this);
63 if (!spanned_drul_[LEFT])
70 Beam::brew_molecule_p () const
72 Molecule *mol_p = new Molecule;
73 Real inter_f = paper ()->internote_f ();
74 Real x0 = stems_[0]->hpos_f ();
75 for (int j=0; j <stems_.size (); j++)
78 Stem * prev = (j > 0)? stems_[j-1] : 0;
79 Stem * next = (j < stems_.size ()-1) ? stems_[j+1] :0;
81 Molecule sb = stem_beams (i, next, prev);
82 Real x = i->hpos_f ()-x0;
83 sb.translate (Offset (x, (x * slope_f_ + left_y_)* inter_f));
86 mol_p->translate_axis (x0 - spanned_drul_[LEFT]->absolute_coordinate (X_AXIS), X_AXIS);
93 Real w= (paper ()->note_width () + width ().length ())/2.0;
94 return Offset (w, (left_y_ + w* slope_f_)*paper ()->internote_f ());
98 Beam::do_pre_processing ()
105 Beam::do_print () const
108 DOUT << "slope_f_ " <<slope_f_ << "left ypos " << left_y_;
109 Spanner::do_print ();
114 Beam::do_post_processing ()
116 if (stems_.size () < 2)
118 warning (_ ("Beam with less than 2 stems"));
119 transparent_b_ = true;
127 Beam::do_substitute_dependent (Score_elem*o,Score_elem*n)
129 if (o->is_type_b (Stem::static_name ()))
130 stems_.substitute ((Stem*)o->item (), n? (Stem*) n->item ():0);
134 Beam::do_width () const
136 return Interval (stems_[0]->hpos_f (),
137 stems_.top ()->hpos_f ());
141 Beam::set_default_dir ()
143 Drul_array<int> total;
144 total[UP] = total[DOWN] = 0;
145 Drul_array<int> count;
146 count[UP] = count[DOWN] = 0;
149 for (int i=0; i <stems_.size (); i++)
152 int current = s->dir_
153 ? (1 + d * s->dir_)/2
154 : s->get_center_distance (Direction (-d));
162 } while ((d *= -1) != DOWN);
167 } while ((d *= -1) != DOWN);
171 [Ross] states that the majority of the notes dictates the
172 direction (and not the mean of "center distance")
174 dir_ = (total[UP] > total[DOWN]) ? UP : DOWN;
176 for (int i=0; i <stems_.size (); i++)
178 Stem *sl = stems_[i];
184 should use minimum energy formulation (cf linespacing)
189 Array<Stem_info> sinfo;
190 for (int j=0; j <stems_.size (); j++)
194 i->set_default_extents ();
195 if (i->invisible_b ())
202 slope_f_ = left_y_ = 0;
203 else if (sinfo.size () == 1)
206 left_y_ = sinfo[0].idealy_f_;
211 Real leftx = sinfo[0].x;
213 for (int i=0; i < sinfo.size (); i++)
216 l.input.push (Offset (sinfo[i].x, sinfo[i].idealy_f_));
219 l.minimise (slope_f_, left_y_);
223 for (int i=0; i < sinfo.size (); i++)
225 Real y = sinfo[i].x * slope_f_ + left_y_;
226 Real my = sinfo[i].miny_f_;
237 This neat trick is by Werner Lemberg, damped = tanh (slope_f_) corresponds
238 with some tables in [Wanske]
241 slope_f_ = 0.6 * tanh (slope_f_) / damping_i_;
245 // y-values traditionally use internote dimension: therefore slope = (y/in)/x
246 // but mf and beam-lookup use PT dimension for y (as used for x-values)
247 // ugh --- there goes our simplified but careful quantisation
248 Real sl = slope_f_ * paper ()->internote_f ();
249 paper ()->lookup_l ()->beam (sl, 20 PT, 1 PT);
250 slope_f_ = sl / paper ()->internote_f ();
254 Beam::quantise_yspan ()
257 [Ross] (simplification of)
258 Try to set slope_f_ complying with y-span of:
260 - beam_thickness / 2 + staffline_thickness / 2
261 - beam_thickness + staffline_thickness
268 Real interline_f = paper ()->interline_f ();
269 Real internote_f = interline_f / 2;
270 Real staffline_thickness = paper ()->rule_thickness ();
271 Real beam_thickness = 0.48 * (interline_f - staffline_thickness);
273 const int QUANTS = 3;
276 beam_thickness / 2 + staffline_thickness / 2,
277 beam_thickness + staffline_thickness
280 Real xspan_f = stems_.top ()->hpos_f () - stems_[0]->hpos_f ();
281 // y-values traditionally use internote dimension: therefore slope = (y/in)/x
282 Real yspan_f = xspan_f * abs (slope_f_ * internote_f);
283 int yspan_i = (int)(yspan_f / interline_f);
284 Real q = (yspan_f / interline_f - yspan_i) * interline_f;
286 for (; i < QUANTS - 1; i++)
287 if ((q >= qdy[i]) && (q <= qdy[i + 1]))
289 if (q - qdy[i] < qdy[i + 1] - q)
299 yspan_f = (Real)yspan_i * interline_f + q;
300 // y-values traditionally use internote dimension: therefore slope = (y/in)/x
301 slope_f_ = yspan_f / xspan_f / internote_f * sign (slope_f_);
305 Beam::quantise_left_y (Beam::Pos pos, bool extend_b)
308 quantising left y should suffice, as slope is quantised too
309 if extend then stems must not get shorter
315 Real interline_f = paper ()->interline_f ();
316 Real internote_f = interline_f / 2;
317 Real staffline_thickness = paper ()->rule_thickness ();
318 Real beam_thickness = 0.48 * (interline_f - staffline_thickness);
320 const int QUANTS = 6;
325 interline_f / 2 + beam_thickness / 2 + staffline_thickness / 2,
327 interline_f + beam_thickness / 2,
330 ugh, using i triggers gcc 2.7.2.1 internal compiler error (far down):
331 for (int i = 0; i < QUANTS; i++)
333 for (int ii = 0; ii < QUANTS; ii++)
334 qy[ii] -= beam_thickness / 2;
344 // y-values traditionally use internote dimension
345 Real y = left_y_ * internote_f;
346 int y_i = (int)floor(y / interline_f);
347 y = (y / interline_f - y_i) * interline_f;
350 for (int ii = 0; ii < QUANTS; ii++)
351 qy[ii] -= interline_f;
355 for (; i < QUANTS; i++)
359 // found if lower_i is allowed, and nearer (from below) y than new pos
360 if ((pos & qpos[lower_i]) && (y - qy[lower_i] < y - qy[i]))
362 // if new pos is allowed or old pos isn't: assign new pos
363 if ((pos & qpos[i]) || !(pos & qpos[lower_i]))
367 int upper_i = QUANTS - 1;
368 for (i = QUANTS - 1; i >= 0; i--)
372 // found if upper_i is allowed, and nearer (from above) y than new pos
373 if ((pos & qpos[upper_i]) && (qy[upper_i] - y < qy[i] - y))
375 // if new pos is allowed or old pos isn't: assign new pos
376 if ((pos & qpos[i]) || !(pos & qpos[upper_i]))
380 // y-values traditionally use internote dimension
381 Real upper_y = (qy[upper_i] + interline_f * y_i) / internote_f;
382 Real lower_y = (qy[lower_i] + interline_f * y_i) / internote_f;
385 left_y_ = (dir_ > 0 ? upper_y : lower_y);
387 left_y_ = (upper_y - left_y_ < y - lower_y ? upper_y : lower_y);
391 Beam::set_stemlens ()
393 Real x0 = stems_[0]->hpos_f ();
396 Real interline_f = paper ()->interline_f ();
397 Real internote_f = interline_f / 2;
398 Real staffline_thickness = paper ()->rule_thickness ();
399 Real beam_thickness = 0.48 * (interline_f - staffline_thickness);
400 Real interbeam_f = paper ()->interbeam_f ();
402 interbeam_f += 2.0 * staffline_thickness / 4;
403 Real xspan_f = stems_.top ()->hpos_f () - stems_[0]->hpos_f ();
405 ugh, y values are in "internote" dimension
407 Real yspan_f = xspan_f * abs (slope_f_ * internote_f);
408 int yspan_i = (int)(yspan_f / interline_f);
412 if ((yspan_f < staffline_thickness / 2) || (quantisation_ == NORMAL))
413 left_pos = (Pos)(STRADDLE | SIT | HANG);
415 left_pos = (Pos) (sign (slope_f_) > 0 ? STRADDLE | HANG
419 ugh, slope currently mangled by availability mf chars...
420 be more generous regarding beam position between stafflines
422 Real q = (yspan_f / interline_f - yspan_i) * interline_f;
423 if (q < interline_f / 3 - beam_thickness / 2)
424 left_pos = (Pos) (left_pos | INTER);
427 left_pos = (Pos) (dir_ > 0 ? HANG : SIT);
429 // ugh, rounding problems!
430 const Real EPSILON = interline_f / 10;
433 left_y_ += dy * dir_;
434 quantise_left_y (left_pos, dy);
436 for (int j=0; j < stems_.size (); j++)
440 Real x = s->hpos_f () - x0;
441 s->set_stemend (left_y_ + slope_f_ * x);
442 Real y = s->stem_length_f ();
443 int mult = max (stems_[j]->beams_left_i_, stems_[j]->beams_right_i_);
445 // dim(y) = internote
446 y -= (mult - 1) * interbeam_f / internote_f;
447 if (y < MINIMUM_STEMLEN[mult])
448 dy = dy >? (MINIMUM_STEMLEN[mult] - y);
450 } while (abs (dy) > EPSILON);
454 Beam::set_grouping (Rhythmic_grouping def, Rhythmic_grouping cur)
458 assert (cur.children.size () == stems_.size ());
465 for (int j=0; j <stems_.size (); j++)
469 int f = s->flag_i_ - 2;
474 b= cur.generate_beams (flags, fi);
477 assert (stems_.size () == b.size ()/2);
480 for (int j=0, i=0; i < b.size () && j <stems_.size (); i+= 2, j++)
483 s->beams_left_i_ = b[i];
484 s->beams_right_i_ = b[i+1];
485 multiple_i_ = multiple_i_ >? (b[i] >? b[i+1]);
490 beams to go with one stem.
493 Beam::stem_beams (Stem *here, Stem *next, Stem *prev) const
495 assert (!next || next->hpos_f () > here->hpos_f ());
496 assert (!prev || prev->hpos_f () < here->hpos_f ());
498 Real staffline_thickness = paper ()->rule_thickness ();
499 Real interbeam_f = paper ()->interbeam_f ();
500 Real internote_f =paper ()->internote_f ();
501 Real interline_f = 2 * internote_f;
502 Real beamheight_f = 0.48 * (interline_f - staffline_thickness);
504 interbeam_f += 2.0 * staffline_thickness / 4;
505 Real dy = interbeam_f;
506 Real stemdx = staffline_thickness;
507 Real sl = slope_f_* internote_f;
508 paper ()->lookup_l ()->beam (sl, 20 PT, 1 PT);
513 /* half beams extending to the left. */
516 int lhalfs= lhalfs = here->beams_left_i_ - prev->beams_right_i_ ;
517 int lwholebeams= here->beams_left_i_ <? prev->beams_right_i_ ;
518 Real w = (here->hpos_f () - prev->hpos_f ())/4 <? paper ()->note_width ();;
520 if (lhalfs) // generates warnings if not
521 a = paper ()->lookup_l ()->beam (sl, w, beamheight_f);
522 a.translate (Offset (-w, -w * sl));
523 for (int j = 0; j < lhalfs; j++)
526 b.translate_axis (-dir_ * dy * (lwholebeams+j), Y_AXIS);
533 int rhalfs = here->beams_right_i_ - next->beams_left_i_;
534 int rwholebeams = here->beams_right_i_ <? next->beams_left_i_;
536 Real w = next->hpos_f () - here->hpos_f ();
537 Atom a = paper ()->lookup_l ()->beam (sl, w + stemdx, beamheight_f);
538 a.translate_axis( - stemdx/2, X_AXIS);
541 if (here->beam_gap_i_)
543 int nogap = rwholebeams - here->beam_gap_i_;
544 for (; j < nogap; j++)
547 b.translate_axis (-dir_ * dy * j, Y_AXIS);
550 // TODO: notehead widths differ for different types
551 gap_f = paper ()->note_width () / 2;
553 a = paper ()->lookup_l ()->beam (sl, w + stemdx, beamheight_f);
556 for (; j < rwholebeams; j++)
559 b.translate (Offset (gap_f, -dir_ * dy * j));
563 w = w/4 <? paper ()->note_width ();
565 a = paper ()->lookup_l ()->beam (sl, w, beamheight_f);
567 for (; j < rwholebeams + rhalfs; j++)
570 b.translate_axis (-dir_ * dy * j, Y_AXIS);
575 leftbeams.add (rightbeams);
578 Does beam quanting think of the asymetry of beams?
579 Refpoint is on bottom of symbol. (FIXTHAT) --hwn.
581 if (experimental_features_global_b && dir_ < 0)
582 leftbeams.translate_axis (-beamheight_f, Y_AXIS);