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[6] = {
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);
169 /* the following relation is equal to
170 up / up_count > down / down_count
172 dir_ = (total[UP] * count[DOWN] > total[DOWN] * count[UP]) ? UP : DOWN;
174 for (int i=0; i <stems.size (); i++)
182 should use minimum energy formulation (cf linespacing)
188 Array<Stem_info> sinfo;
189 for (int j=0; j <stems.size (); j++)
193 i->set_default_extents ();
194 if (i->invisible_b ())
201 slope_f = left_y = 0;
202 else if (sinfo.size () == 1)
205 left_y = sinfo[0].idealy_f_;
210 Real leftx = sinfo[0].x;
212 for (int i=0; i < sinfo.size (); i++)
215 l.input.push (Offset (sinfo[i].x, sinfo[i].idealy_f_));
218 l.minimise (slope_f, left_y);
222 for (int i=0; i < sinfo.size (); i++)
224 Real y = sinfo[i].x * slope_f + left_y;
225 Real my = sinfo[i].miny_f_;
236 This neat trick is by Werner Lemberg, damped = tanh (slope_f) corresponds
237 with some tables in [Wanske]
240 slope_f = 0.6 * tanh (slope_f) / damping_i_;
244 // y-values traditionally use internote dimension: therefore slope = (y/in)/x
245 // but mf and beam-lookup use PT dimension for y (as used for x-values)
246 // ugh --- there goes our simplified but careful quantisation
247 Real sl = slope_f * paper ()->internote_f ();
248 paper ()->lookup_l ()->beam (sl, 20 PT);
249 slope_f = sl / paper ()->internote_f ();
253 Beam::quantise_yspan ()
256 [Ross] (simplification of)
257 Try to set slope_f complying with y-span of:
259 - beam_thickness / 2 + staffline_thickness / 2
260 - beam_thickness + staffline_thickness
267 Real interline_f = paper ()->interline_f ();
268 Real internote_f = interline_f / 2;
269 Real staffline_thickness = paper ()->rule_thickness ();
270 Real beam_thickness = 0.48 * (interline_f - staffline_thickness);
272 const int QUANTS = 3;
275 beam_thickness / 2 + staffline_thickness / 2,
276 beam_thickness + staffline_thickness
279 Real xspan_f = stems.top ()->hpos_f () - stems[0]->hpos_f ();
280 // y-values traditionally use internote dimension: therefore slope = (y/in)/x
281 Real yspan_f = xspan_f * abs (slope_f * internote_f);
282 int yspan_i = (int)(yspan_f / interline_f);
283 Real q = (yspan_f / interline_f - yspan_i) * interline_f;
285 for (; i < QUANTS - 1; i++)
286 if ((q >= qdy[i]) && (q <= qdy[i + 1]))
288 if (q - qdy[i] < qdy[i + 1] - q)
298 yspan_f = (Real)yspan_i * interline_f + q;
299 // y-values traditionally use internote dimension: therefore slope = (y/in)/x
300 slope_f = yspan_f / xspan_f / internote_f * sign (slope_f);
304 Beam::quantise_left_y (Beam::Pos pos, bool extend_b)
307 quantising left y should suffice, as slope is quantised too
308 if extend then stems must not get shorter
314 Real interline_f = paper ()->interline_f ();
315 Real internote_f = interline_f / 2;
316 Real staffline_thickness = paper ()->rule_thickness ();
317 Real beam_thickness = 0.48 * (interline_f - staffline_thickness);
319 const int QUANTS = 6;
324 interline_f / 2 + beam_thickness / 2 + staffline_thickness / 2,
326 interline_f + beam_thickness / 2,
329 ugh, using i triggers gcc 2.7.2.1 internal compiler error (far down):
330 for (int i = 0; i < QUANTS; i++)
332 for (int ii = 0; ii < QUANTS; ii++)
333 qy[ii] -= beam_thickness / 2;
343 // y-values traditionally use internote dimension
344 Real y = left_y * internote_f;
345 int y_i = (int)floor(y / interline_f);
346 y = (y / interline_f - y_i) * interline_f;
349 for (int ii = 0; ii < QUANTS; ii++)
350 qy[ii] -= interline_f;
354 for (; i < QUANTS; i++)
358 // found if lower_i is allowed, and nearer (from below) y than new pos
359 if ((pos & qpos[lower_i]) && (y - qy[lower_i] < y - qy[i]))
361 // if new pos is allowed or old pos isn't: assign new pos
362 if ((pos & qpos[i]) || !(pos & qpos[lower_i]))
366 int upper_i = QUANTS - 1;
367 for (i = QUANTS - 1; i >= 0; i--)
371 // found if upper_i is allowed, and nearer (from above) y than new pos
372 if ((pos & qpos[upper_i]) && (qy[upper_i] - y < qy[i] - y))
374 // if new pos is allowed or old pos isn't: assign new pos
375 if ((pos & qpos[i]) || !(pos & qpos[upper_i]))
379 // y-values traditionally use internote dimension
380 Real upper_y = (qy[upper_i] + interline_f * y_i) / internote_f;
381 Real lower_y = (qy[lower_i] + interline_f * y_i) / internote_f;
384 left_y = (dir_ > 0 ? upper_y : lower_y);
386 left_y = (upper_y - left_y < y - lower_y ? upper_y : lower_y);
390 Beam::set_stemlens ()
392 Real x0 = stems[0]->hpos_f ();
395 Real interline_f = paper ()->interline_f ();
396 Real internote_f = interline_f / 2;
397 Real staffline_thickness = paper ()->rule_thickness ();
398 Real beam_thickness = 0.48 * (interline_f - staffline_thickness);
399 Real interbeam_f = paper ()->interbeam_f ();
401 interbeam_f += 2.0 * staffline_thickness / 4;
402 Real xspan_f = stems.top ()->hpos_f () - stems[0]->hpos_f ();
404 ugh, y values are in "internote" dimension
406 Real yspan_f = xspan_f * abs (slope_f * internote_f);
407 int yspan_i = (int)(yspan_f / interline_f);
411 if ((yspan_f < staffline_thickness / 2) || (quantisation_ == NORMAL))
412 left_pos = (Pos)(STRADDLE | SIT | HANG);
414 left_pos = (Pos) (sign (slope_f) > 0 ? STRADDLE | HANG
418 ugh, slope currently mangled by availability mf chars...
419 be more generous regarding beam position between stafflines
421 Real q = (yspan_f / interline_f - yspan_i) * interline_f;
422 if (q < interline_f / 3 - beam_thickness / 2)
423 left_pos = (Pos) (left_pos | INTER);
425 if (stems[0]->beams_right_i_ > 1)
426 left_pos = (Pos) (dir_ > 0 ? HANG : SIT);
428 // ugh, rounding problems!
429 const Real EPSILON = interline_f / 10;
433 quantise_left_y (left_pos, dy);
435 for (int j=0; j < stems.size (); j++)
439 Real x = s->hpos_f () - x0;
440 s->set_stemend (left_y + slope_f * x);
441 Real y = s->stem_length_f ();
442 int mult = max (stems[j]->beams_left_i_, stems[j]->beams_right_i_);
444 // dim(y) = internote
445 y -= (mult - 1) * interbeam_f / internote_f;
446 if (y < MINIMUM_STEMLEN[mult])
447 dy = dy >? (MINIMUM_STEMLEN[mult] - y);
449 } while (abs (dy) > EPSILON);
453 Beam::set_grouping (Rhythmic_grouping def, Rhythmic_grouping cur)
457 assert (cur.children.size () == stems.size ());
464 for (int j=0; j <stems.size (); j++)
468 int f = s->flag_i_ - 2;
473 b= cur.generate_beams (flags, fi);
476 assert (stems.size () == b.size ()/2);
479 for (int j=0, i=0; i < b.size () && j <stems.size (); i+= 2, j++)
482 s->beams_left_i_ = b[i];
483 s->beams_right_i_ = b[i+1];
484 multiple_i_ = multiple_i_ >? (b[i] >? b[i+1]);
489 beams to go with one stem.
492 Beam::stem_beams (Stem *here, Stem *next, Stem *prev) const
494 assert (!next || next->hpos_f () > here->hpos_f ());
495 assert (!prev || prev->hpos_f () < here->hpos_f ());
496 Real staffline_thickness = paper ()->rule_thickness ();
497 Real interbeam_f = paper ()->interbeam_f ();
499 interbeam_f += 2.0 * staffline_thickness / 4;
500 Real dy = interbeam_f;
501 Real stemdx = staffline_thickness;
502 Real sl = slope_f*paper ()->internote_f ();
503 paper ()->lookup_l ()->beam (sl, 20 PT);
508 /* half beams extending to the left. */
511 int lhalfs= lhalfs = here->beams_left_i_ - prev->beams_right_i_ ;
512 int lwholebeams= here->beams_left_i_ <? prev->beams_right_i_ ;
513 Real w = (here->hpos_f () - prev->hpos_f ())/4;
515 if (lhalfs) // generates warnings if not
516 a = paper ()->lookup_l ()->beam (sl, w);
517 a.translate (Offset (-w, -w * sl));
518 for (int j = 0; j < lhalfs; j++)
521 b.translate_axis (-dir_ * dy * (lwholebeams+j), Y_AXIS);
528 int rhalfs = here->beams_right_i_ - next->beams_left_i_;
529 int rwholebeams = here->beams_right_i_ <? next->beams_left_i_;
531 Real w = next->hpos_f () - here->hpos_f ();
532 Atom a = paper ()->lookup_l ()->beam (sl, w + stemdx);
536 if (here->beam_gap_i_)
538 int nogap = rwholebeams - here->beam_gap_i_;
539 for (; j < nogap; j++)
542 b.translate_axis (-dir_ * dy * j, Y_AXIS);
545 // TODO: notehead widths differ for different types
546 gap_f = paper ()->note_width () / 2;
548 a = paper ()->lookup_l ()->beam (sl, w + stemdx);
551 for (; j < rwholebeams; j++)
554 b.translate (Offset (gap_f, -dir_ * dy * j));
560 a = paper ()->lookup_l ()->beam (sl, w);
562 for (; j < rwholebeams + rhalfs; j++)
565 b.translate_axis (-dir_ * dy * j, Y_AXIS);
570 leftbeams.add (rightbeams);