lily/spacing-spanner.cc

   1 /*
   2   spacing-spanner.cc --  implement Spacing_spanner
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1999--2000 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8  */
   9
  10 #include "spacing-spanner.hh"
  11 #include "paper-column.hh"
  12 #include "dimensions.hh"
  13 #include "paper-def.hh"
  14 #include "warn.hh"
  15 #include "paper-score.hh"
  16 #include "line-of-score.hh"
  17 #include "misc.hh"
  18
  19 void
  20 Spacing_spanner::set_interface (Score_element*me)
  21 {
  22   me->set_extent_callback (0, X_AXIS);
  23   me->set_extent_callback (0, Y_AXIS);
  24 }
  25
  26 /*
  27
  28   The algorithm is partly taken from :
  29
  30   John S. Gourlay. ``Spacing a Line of Music,'' Technical Report
  31   OSU-CISRC-10/87-TR35, Department of Computer and Information
  32   Science, The Ohio State University, 1987.
  33
  34   TOO HAIRY.
  35
  36   TODO: write comments
  37
  38  */
  39 void
  40 Spacing_spanner::do_measure (Score_element*me, Link_array<Score_element> cols)
  41 {
  42   Moment shortest;
  43   Moment mean_shortest;
  44
  45   /*
  46     space as if this duration  is present.
  47    */
  48   Moment base_shortest_duration = *unsmob_moment (me->get_elt_property ("maximum-duration-for-spacing"));
  49   shortest.set_infinite (1);
  50
  51   int n = 0;
  52   for (int i =0 ; i < cols.size (); i++)
  53     {
  54       if (dynamic_cast<Paper_column*> (cols[i])->musical_b ())
  55         {
  56           SCM  st = cols[i]->get_elt_property ("shortest-starter-duration");
  57           Moment this_shortest = *unsmob_moment(st);
  58           shortest = shortest <? this_shortest;
  59           if (!mean_shortest.infty_b ())
  60             {
  61               n++;
  62               mean_shortest += this_shortest;
  63             }
  64         }
  65     }
  66   mean_shortest /= n;
  67
  68   Real non_musical_space_strength = me->paper_l ()->get_var ("breakable_column_space_strength");
  69   for (int i= 0; i < cols.size () - 1; i++)
  70     {
  71       Item * l = dynamic_cast<Item*> (cols[i]);
  72       Item * r =  dynamic_cast<Item*> (cols[i+1]);
  73       Item * lb = dynamic_cast<Item*> ( l->find_prebroken_piece (RIGHT));
  74       Item * rb = dynamic_cast<Item*> ( r->find_prebroken_piece (LEFT));
  75
  76       Item* combinations[4][2]={{l,r}, {lb,r}, {l,rb},{lb,rb}};
  77
  78       for (int j=0; j < 4; j++)
  79         {
  80           Paper_column * lc = dynamic_cast<Paper_column*> (combinations[j][0]);
  81           Paper_column *rc = dynamic_cast<Paper_column*> (combinations[j][1]);
  82           if (!lc || !rc)
  83             continue;
  84
  85           Spring s;
  86           s.item_l_drul_[LEFT] = lc;
  87           s.item_l_drul_[RIGHT] = rc;
  88
  89           SCM hint = lc->get_elt_property ("extra-space");
  90           SCM next_hint = rc->get_elt_property ("extra-space");
  91           SCM stretch_hint = lc->get_elt_property ("stretch-distance");
  92           SCM next_stretch_hint = rc->get_elt_property ("stretch-distance");
  93
  94           Real left_distance;
  95           if (gh_pair_p (hint))
  96             {
  97               left_distance = gh_scm2double (gh_cdr (hint));
  98             }
  99            // 2nd condition should be (i+1 < col_count()), ie. not the last column in score.  FIXME
 100           else if (!lc->musical_b() && i+1 < cols.size ())
 101             {
 102               left_distance= default_bar_spacing (me,lc,rc,shortest <? base_shortest_duration);
 103             }
 104           else if (lc->musical_b())
 105             {
 106               left_distance  = note_spacing (me,lc, rc, shortest <? base_shortest_duration);
 107             }
 108
 109           s.distance_f_ = left_distance;
 110
 111           /*
 112             Only do tight spaces *after* barlines (breakable columns),
 113             not before.
 114
 115             We want the space before barline to be like the note
 116             spacing in the measure.
 117           */
 118           if (Item::breakable_b (lc) || lc->original_l_)
 119             s.strength_f_ = non_musical_space_strength;
 120           else if (!lc->musical_b ())
 121             left_distance *= me->paper_l ()->get_var ("decrease_nonmus_spacing_factor");
 122
 123
 124           Real right_dist = 0.0;
 125           if (gh_pair_p (next_hint))
 126             {
 127               right_dist += - gh_scm2double (gh_car (next_hint));
 128             }
 129           else
 130             {
 131               Interval ext (rc->extent (X_AXIS));
 132               right_dist =  ext.empty_b() ? 0.0 : - ext [LEFT];
 133             }
 134
 135           /*
 136             don't want to create too much extra space for accidentals
 137           */
 138           if (lc->musical_b () && rc->musical_b ())
 139             {
 140               if (!to_boolean (rc->get_elt_property ("contains-grace")))
 141                 right_dist *= me->paper_l ()->get_var ("musical_to_musical_left_spacing_factor");
 142             }
 143
 144           if (rc->musical_b () && to_boolean (rc->get_elt_property ("contains-grace")))
 145             right_dist *= me->paper_l ()->get_var ("before_grace_spacing_factor");
 146
 147           s.distance_f_ = left_distance + right_dist;
 148
 149           Real stretch_dist = 0.;
 150           if (gh_number_p (stretch_hint))
 151             stretch_dist += gh_scm2double (stretch_hint);
 152           else
 153             stretch_dist += left_distance;
 154
 155           if (gh_pair_p (next_stretch_hint))
 156             // see regtest spacing-tight
 157             stretch_dist += - gh_scm2double (gh_car  (next_stretch_hint));
 158           else
 159             stretch_dist += right_dist;
 160
 161           if (s.distance_f_ <0)
 162             {
 163               programming_error("Negative dist, setting to 1.0 PT");
 164               s.distance_f_ = 1.0;
 165             }
 166           if (stretch_dist == 0.0)
 167             {
 168               /*
 169                 \bar "".  We give it 0 space, with high strength.
 170                */
 171               s.strength_f_ = 20.0;
 172             }
 173           else
 174             s.strength_f_ /= stretch_dist;
 175
 176           s.add_to_cols ();
 177         }
 178     }
 179
 180 }
 181
 182 /**
 183    Do something if breakable column has no spacing hints set.
 184  */
 185 Real
 186 Spacing_spanner::default_bar_spacing (Score_element*me, Score_element *lc, Score_element *rc,
 187                                       Moment shortest)
 188 {
 189   Real symbol_distance = lc->extent (X_AXIS)[RIGHT] ;
 190   Real durational_distance = 0;
 191   Moment delta_t = Paper_column::when_mom (rc) - Paper_column::when_mom (lc);
 192
 193   /*
 194                 ugh should use shortest_playing distance
 195   */
 196   if (delta_t)
 197     {
 198       durational_distance =  get_duration_space (me, delta_t, shortest);
 199     }
 200
 201   return  symbol_distance >? durational_distance;
 202 }
 203
 204
 205 /**
 206   Get the measure wide ant for arithmetic spacing.
 207
 208   @see
 209   John S. Gourlay. ``Spacing a Line of Music,'' Technical Report
 210   OSU-CISRC-10/87-TR35, Department of Computer and Information Science,
 211   The Ohio State University, 1987.
 212
 213   */
 214 Real
 215 Spacing_spanner::get_duration_space (Score_element*me, Moment d, Moment shortest)
 216 {
 217   Real log =  log_2 (shortest);
 218   Real k=   me->paper_l ()->get_var ("arithmetic_basicspace")
 219     - log;
 220
 221   return (log_2 (d) + k) * me->paper_l ()->get_var ("arithmetic_multiplier");
 222 }
 223
 224
 225 Real
 226 Spacing_spanner::note_spacing (Score_element*me, Score_element *lc, Score_element *rc,
 227                                Moment shortest)
 228 {
 229   Moment shortest_playing_len = 0;
 230   SCM s = lc->get_elt_property ("shortest-playing-duration");
 231
 232   //  SCM s = lc->get_elt_property ("mean-playing-duration");
 233   if (unsmob_moment (s))
 234     shortest_playing_len = *unsmob_moment(s);
 235
 236   if (! shortest_playing_len)
 237     {
 238       programming_error ("can't find a ruling note at " + Paper_column::when_mom (lc).str ());
 239       shortest_playing_len = 1;
 240     }
 241
 242   if (! shortest)
 243     {
 244       programming_error ("no minimum in measure at " + Paper_column::when_mom (lc).str ());
 245       shortest = 1;
 246     }
 247   Moment delta_t = Paper_column::when_mom (rc) - Paper_column::when_mom (lc);
 248   Real dist = get_duration_space (me, shortest_playing_len, shortest);
 249   dist *= (double)(delta_t / shortest_playing_len);
 250
 251   /*
 252     UGH: KLUDGE!
 253   */
 254
 255   if (delta_t > Moment (1,32))
 256     dist += stem_dir_correction (me, lc,rc);
 257   return dist;
 258 }
 259
 260
 261 /**
 262    Correct for optical illusions. See [Wanske] p. 138. The combination
 263    up-stem + down-stem should get extra space, the combination
 264    down-stem + up-stem less.
 265
 266    This should be more advanced, since relative heights of the note
 267    heads also influence required correction.
 268
 269    Also might not work correctly in case of multi voices or staff
 270    changing voices
 271
 272    TODO: lookup correction distances?  More advanced correction?
 273    Possibly turn this off?
 274
 275    TODO: have to check wether the stems are in the same staff.
 276
 277    This routine reads the DIR-LIST property of both its L and R arguments.  */
 278 Real
 279 Spacing_spanner::stem_dir_correction (Score_element*me, Score_element*l, Score_element*r)
 280 {
 281   SCM dl = l->get_elt_property ("dir-list");
 282   SCM dr = r->get_elt_property ("dir-list");
 283
 284   if (scm_ilength (dl) != 1 || scm_ilength (dr) != 1)
 285     return 0.;
 286
 287   dl = gh_car (dl);
 288   dr = gh_car (dr);
 289
 290   assert (gh_number_p (dl) && gh_number_p(dr));
 291   int d1 = gh_scm2int (dl);
 292   int d2 = gh_scm2int (dr);
 293
 294   if (d1 == d2)
 295     return 0.0;
 296
 297
 298   Real correction = 0.0;
 299   Real ssc = me->paper_l ()->get_var("stemSpacingCorrection");
 300
 301
 302   if (d1 && d2 && d1 * d2 == -1)
 303     {
 304       correction = d1 * ssc;
 305     }
 306   else
 307     programming_error ("Stem directions not set correctly for optical correction");
 308   return correction;
 309 }
 310
 311
 312 MAKE_SCHEME_CALLBACK(Spacing_spanner, set_springs);
 313 SCM
 314 Spacing_spanner::set_springs (SCM smob)
 315 {
 316   Score_element *me = unsmob_element (smob);
 317   Link_array<Score_element> all (me->pscore_l_->line_l_->column_l_arr ()) ;
 318
 319   int j = 0;
 320
 321   for (int i = 1; i < all.size (); i++)
 322     {
 323       Score_element *sc = all[i];
 324       if (Item::breakable_b (sc))
 325         {
 326           Link_array<Score_element> measure (all.slice (j, i+1));
 327           do_measure (me, measure);
 328           j = i;
 329         }
 330     }
 331
 332   /*
 333     farewell, cruel world
 334    */
 335   me->suicide ();
 336   return SCM_UNSPECIFIED;
 337 }
 338
 339
 340
 341
 342