lily/slur.cc

   1 /*
   2   slur.cc -- implement  Slur
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1996, 1997 Han-Wen Nienhuys <hanwen@stack.nl>
   7 */
   8
   9 /*
  10   TODO:
  11
  12   think about crossing stems.
  13   Begin and end should be treated as a Script.
  14  */
  15 #include "slur.hh"
  16 #include "scalar.hh"
  17 #include "lookup.hh"
  18 #include "paper-def.hh"
  19 #include "note-column.hh"
  20 #include "stem.hh"
  21 #include "p-col.hh"
  22 #include "molecule.hh"
  23 #include "debug.hh"
  24 #include "boxes.hh"
  25 #include "bezier.hh"
  26 #include "main.hh"
  27
  28 IMPLEMENT_IS_TYPE_B1(Slur,Spanner);
  29
  30 void
  31 Slur::add (Note_column*n)
  32 {
  33   encompass_arr_.push (n);
  34   add_dependency (n);
  35 }
  36
  37 void
  38 Slur::set_default_dir ()
  39 {
  40   dir_ = DOWN;
  41   for (int i=0; i < encompass_arr_.size (); i ++)
  42     {
  43       if (encompass_arr_[i]->dir_ < 0)
  44         {
  45           dir_ = UP;
  46           break;
  47         }
  48     }
  49 }
  50
  51 void
  52 Slur::do_add_processing ()
  53 {
  54   set_bounds (LEFT, encompass_arr_[0]);
  55   if (encompass_arr_.size () > 1)
  56     set_bounds (RIGHT, encompass_arr_.top ());
  57 }
  58
  59 void
  60 Slur::do_pre_processing ()
  61 {
  62   // don't set directions
  63 }
  64
  65 void
  66 Slur::do_substitute_dependency (Score_elem*o, Score_elem*n)
  67 {
  68   int i;
  69   while ((i = encompass_arr_.find_i ((Note_column*)o->item ())) >=0)
  70     {
  71       if (n)
  72         encompass_arr_[i] = (Note_column*)n->item ();
  73       else
  74         encompass_arr_.del (i);
  75     }
  76 }
  77
  78 static int
  79 Note_column_compare (Note_column *const&n1 , Note_column* const&n2)
  80 {
  81   return Item::left_right_compare (n1, n2);
  82 }
  83
  84 void
  85 Slur::do_post_processing ()
  86 {
  87   encompass_arr_.sort (Note_column_compare);
  88   if (!dir_)
  89     set_default_dir ();
  90   Real interline_f = paper ()->interline_f ();
  91   Real inter_f = interline_f / 2;
  92
  93   /*
  94    [OSU]: slur and tie placement
  95
  96    slurs:
  97    * x = centre of head (upside-down: inner raakpunt stem) - d * gap
  98
  99    * y = length < 5ss : horizontal raakpunt + d * 0.25 ss
 100      y = length >= 5ss : y next interline - d * 0.25 ss
 101      --> height <= 5 length ?? we use <= 3 length, now...
 102
 103    * suggested gap = ss / 5;
 104    */
 105   // jcn: 1/5 seems so small?
 106   Real gap_f = interline_f / 2; // 5;
 107
 108   Drul_array<Note_column*> extrema;
 109   extrema[LEFT] = encompass_arr_[0];
 110   extrema[RIGHT] = encompass_arr_.top ();
 111
 112   Direction d=LEFT;
 113   Real nw_f = paper ()->note_width ();
 114
 115   do
 116     {
 117       if (extrema[d] != spanned_drul_[d])
 118         {
 119           dx_f_drul_[d] = -d
 120             *(spanned_drul_[d]->width ().length () -0.5*nw_f);
 121         }
 122       else if (extrema[d]->stem_l_ && !extrema[d]->stem_l_->transparent_b_)
 123         {
 124           dy_f_drul_[d] = (int)rint (extrema[d]->stem_l_->height ()[dir_]);
 125           /* normal slur from notehead centre to notehead centre, minus gap */
 126           // ugh: diff between old and new slurs
 127           if (!experimental_features_global_b)
 128             dx_f_drul_[d] += -d * gap_f;
 129           else
 130             dx_f_drul_[d] += 0.5 * nw_f - d * gap_f;
 131         }
 132       else
 133         {
 134           dy_f_drul_[d] = (int)rint (extrema[d]->head_positions_interval ()[dir_])* inter_f;
 135         }
 136       dy_f_drul_[d] += dir_ * interline_f;
 137     }
 138   while (flip(&d) != LEFT);
 139 }
 140
 141 Real
 142 Slur::height_f () const
 143 {
 144   Bezier_bow bow (paper ());
 145   Array<Offset> notes = get_notes ();
 146   bow.set (notes, dir_);
 147
 148   Real height = 0;
 149   Real dy1 = bow.calc_f (height);
 150   if (!dy1)
 151     return height;
 152
 153   height = dy1;
 154   bow.set (notes, dir_);
 155   Real dy2 = bow.calc_f (height);
 156   if (!dy2)
 157     return height;
 158
 159   if (abs (dy2 - dy1) < paper ()->rule_thickness ())
 160     return height;
 161
 162   /*
 163     Assume
 164       dy = B (h)
 165     with
 166       B (h) = a * h + b;
 167
 168     Then we get for height = h{dy=0}
 169    */
 170   Real a = (dy2 - dy1) / dy1;
 171   Real b = dy1;
 172   height = -b / a;
 173
 174   if (check_debug && !monitor->silent_b ("Slur"))
 175     {
 176       cout << "************" << endl;
 177       cout << "dy1: " << dy1 << endl;
 178       cout << "dy2: " << dy2 << endl;
 179       cout << "a: " << a << endl;
 180       cout << "b: " << b << endl;
 181       cout << "h: " << height << endl;
 182     }
 183
 184   return height;
 185 }
 186
 187 Molecule*
 188 Slur::brew_molecule_p () const
 189 {
 190   if (!experimental_features_global_b)
 191     return Bow::brew_molecule_p ();
 192
 193   Molecule* mol_p = new Molecule;
 194
 195   Real dy_f = dy_f_drul_[RIGHT] - dy_f_drul_[LEFT];
 196
 197   Real dx_f = width ().length ();
 198   dx_f += (dx_f_drul_[RIGHT] - dx_f_drul_[LEFT]);
 199
 200   Atom a = paper ()->lookup_l ()->control_slur (get_controls (), dx_f, dy_f);
 201
 202   Real interline_f = paper ()->interline_f ();
 203   Real gap_f = interline_f / 2; // 5;
 204   Real nw_f = paper ()->note_width ();
 205   a.translate (Offset (dx_f + 0.5 * nw_f + gap_f, dy_f + dy_f_drul_[LEFT]));
 206   mol_p->add (a);
 207   return mol_p;
 208 }
 209
 210 Array<Offset>
 211 Slur::get_notes () const
 212 {
 213   Real interline = paper ()->interline_f ();
 214   Real notewidth = paper ()->note_width ();
 215   Real internote = interline / 2;
 216
 217   Stem* left_stem = encompass_arr_[0]->stem_l_;
 218   Real left_x = left_stem->hpos_f ();
 219   // ugh, do bow corrections (see brew_mol)
 220   left_x += dx_f_drul_[LEFT] + 0.5 * notewidth;
 221
 222   // ugh, do bow corrections (see brew_mol)
 223   Real left_y = dy_f_drul_[LEFT];
 224   // ugh, where does this asymmetry come from?
 225   if (dir_ == DOWN)
 226     left_y -= dir_ * internote;
 227
 228   /*
 229     urg, corrections for broken slurs: extra begin or end position
 230    */
 231   int first = 0;
 232   int n = encompass_arr_.size ();
 233   if (encompass_arr_[0] != spanned_drul_[LEFT])
 234     {
 235       n += 1;
 236       first = 1;
 237       left_x = spanned_drul_[LEFT]->width ().length ();
 238       left_y = 0;
 239     }
 240   if (encompass_arr_.top () != spanned_drul_[RIGHT])
 241       n += 1;
 242
 243   Array<Offset> notes;
 244   notes.set_size (n);
 245
 246   Real dx = width ().length ();
 247   dx += (dx_f_drul_[RIGHT] - dx_f_drul_[LEFT]);
 248   dx = dx <? 1000;
 249   dx = dx >? 2 * interline;
 250
 251   Real dy = (dy_f_drul_[RIGHT] - dy_f_drul_[LEFT]);
 252   if (abs (dy) > 1000)
 253     dy = sign (dy) * 1000;
 254
 255   notes[0].x () = 0;
 256   notes[0].y () = 0;
 257   notes[n - 1].x () = dx;
 258   notes[n - 1].y () = dy;
 259   for (int i = 1; i < n - 1; i++)
 260     {
 261       Stem* stem = encompass_arr_[i - first]->stem_l_;
 262       /*
 263         set x to middle of notehead or on exact x position of stem,
 264         according to slur direction
 265            */
 266       Real x = stem->hpos_f () - left_x + notewidth / 2;
 267       if (stem->dir_ != dir_)
 268         x += notewidth / 2;
 269       else if (stem->dir_ == UP)
 270         x += notewidth;
 271       Real y = stem->dir_ == dir_ ? stem->stem_end_f ()
 272         : stem->stem_begin_f () + 2.5 * dir_;
 273
 274       /*
 275         leave a gap: slur mustn't touch head/stem
 276        */
 277       y += 2.5 * dir_;
 278       y *= internote;
 279       y -= left_y;
 280
 281       notes[i].x () = x;
 282       notes[i].y () = y;
 283     }
 284   return notes;
 285 }
 286
 287 Array<Offset>
 288 Slur::get_controls () const
 289 {
 290   Bezier_bow b (paper ());
 291   b.set (get_notes (), dir_);
 292   b.calc ();
 293   Array<Offset> controls;
 294   controls.set_size (8);
 295   for (int i = 0; i < 4; i++)
 296     controls[i] = b.control_[i];
 297   for (int i = 0; i < 4; i++)
 298     controls[i + 4] = b.return_[i];
 299   return controls;
 300 }
 301