lily/ledger-line-spanner.cc

   1 /*
   2   ledger-line-spanner.cc -- implement Ledger_line_spanner
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2004--2005 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include <map>
  10
  11 #include "item.hh"
  12 #include "note-head.hh"
  13 #include "staff-symbol-referencer.hh"
  14 #include "staff-symbol.hh"
  15 #include "lookup.hh"
  16 #include "spanner.hh"
  17 #include "group-interface.hh"
  18 #include "paper-column.hh"
  19
  20 struct Ledger_line_spanner
  21 {
  22   DECLARE_SCHEME_CALLBACK (print, (SCM));
  23   DECLARE_SCHEME_CALLBACK (set_spacing_rods, (SCM));
  24   static Stencil brew_ledger_lines (Grob *me,
  25                                     int pos,
  26                                     int interspaces,
  27                                     Real, Real,
  28                                     Interval x_extent,
  29                                     Real left_shorten);
  30
  31   static bool has_interface (Grob *);
  32 };
  33
  34 Stencil
  35 Ledger_line_spanner::brew_ledger_lines (Grob *staff,
  36                                         int pos,
  37                                         int interspaces,
  38                                         Real halfspace,
  39                                         Real ledgerlinethickness,
  40                                         Interval x_extent,
  41                                         Real left_shorten)
  42 {
  43   int line_count = ((abs (pos) < interspaces)
  44                     ? 0
  45                     : (abs (pos) - interspaces) / 2);
  46   Stencil stencil;
  47   if (line_count)
  48     {
  49       Real blotdiameter = ledgerlinethickness;
  50       Interval y_extent
  51         = Interval (-0.5* (ledgerlinethickness),
  52                     +0.5* (ledgerlinethickness));
  53       Stencil proto_ledger_line
  54         = Lookup::round_filled_box (Box (x_extent, y_extent), blotdiameter);
  55
  56       x_extent[LEFT] += left_shorten;
  57       Stencil proto_first_line
  58         = Lookup::round_filled_box (Box (x_extent, y_extent), blotdiameter);
  59
  60       Direction dir = (Direction)sign (pos);
  61       Real offs = (Staff_symbol_referencer::on_staffline (staff, pos))
  62         ? 0.0
  63         : -dir * halfspace;
  64
  65       offs += pos * halfspace;
  66       for (int i = 0; i < line_count; i++)
  67         {
  68           Stencil ledger_line ((i == 0)
  69                                ? proto_first_line
  70                                : proto_ledger_line);
  71           ledger_line.translate_axis (-dir * halfspace * i * 2 + offs, Y_AXIS);
  72           stencil.add_stencil (ledger_line);
  73         }
  74     }
  75
  76   return stencil;
  77 }
  78
  79 MAKE_SCHEME_CALLBACK (Ledger_line_spanner, set_spacing_rods, 1);
  80 SCM
  81 Ledger_line_spanner::set_spacing_rods (SCM smob)
  82 {
  83   Spanner *me = dynamic_cast<Spanner *> (unsmob_grob (smob));
  84
  85   // find size of note heads.
  86   Grob *staff = Staff_symbol_referencer::get_staff_symbol (me);
  87   if (!staff)
  88     return SCM_EOL;
  89
  90   SCM heads = me->get_property ("note-heads");
  91
  92
  93   Real min_length_fraction
  94     = robust_scm2double (me->get_property ("minimum-length-fraction"), 0.15);
  95
  96
  97   Drul_array<Interval> current_extents;
  98   Drul_array<Interval> previous_extents;
  99   Item *previous_column = 0;
 100   Item *current_column = 0;
 101
 102   /*
 103     Run through heads using a loop. Since Legder_line_spanner can
 104     contain a lot of noteheads, we don't use an STL map or set.
 105   */
 106   int interspaces = Staff_symbol::line_count (staff) - 1;
 107   for (SCM hp = heads; scm_is_pair (hp); hp = scm_cdr (hp))
 108     {
 109       Item *h = dynamic_cast<Item *> (unsmob_grob (scm_car (hp)));
 110
 111       int pos = Staff_symbol_referencer::get_rounded_position (h);
 112       if (abs (pos) <= interspaces)
 113         continue;
 114
 115       Item *column = h->get_column ();
 116       if (current_column != column)
 117         {
 118           Direction d = UP;
 119           do
 120             {
 121               if (!current_extents[d].is_empty ()
 122                   && !previous_extents[d].is_empty ())
 123                 {
 124                   Real total_head_length = previous_extents[d].length ()
 125                     + current_extents[d].length ();
 126
 127                   Rod rod;
 128                   rod.distance_ = total_head_length
 129                     * (3/2 * min_length_fraction)
 130                     /*
 131                       we go from right to left.
 132                      */
 133                     - previous_extents[d][LEFT]
 134                     + current_extents[d][RIGHT];
 135
 136                   rod.item_drul_[LEFT] = current_column;
 137                   rod.item_drul_[RIGHT] = previous_column;
 138                   rod.add_to_cols ();
 139                 }
 140             }
 141           while (flip (&d) != DOWN);
 142
 143           previous_column = current_column;
 144           current_column = column;
 145           previous_extents = current_extents;
 146
 147           current_extents[DOWN].set_empty();
 148           current_extents[UP].set_empty();
 149         }
 150
 151
 152       Interval head_extent = h->extent (column, X_AXIS);
 153       Direction vdir = Direction (sign (pos));
 154       if (!vdir)
 155         continue;
 156
 157       current_extents[vdir].unite (head_extent);
 158     }
 159
 160   return SCM_UNSPECIFIED;
 161 }
 162
 163 struct Ledger_request
 164 {
 165   Interval ledger_extent_;
 166   Interval head_extent_;
 167   int position_;
 168   bool excentric_;
 169   Ledger_request ()
 170   {
 171     ledger_extent_.set_empty ();
 172     head_extent_.set_empty ();
 173     position_ = 0;
 174   }
 175 };
 176
 177 typedef std::map < int, Drul_array<Ledger_request> > Ledger_requests;
 178
 179 /*
 180   TODO: ledger share a lot of info. Lots of room to optimize away
 181   common use of objects/variables.
 182
 183 */
 184 MAKE_SCHEME_CALLBACK (Ledger_line_spanner, print, 1);
 185 SCM
 186 Ledger_line_spanner::print (SCM smob)
 187 {
 188   Spanner *me = dynamic_cast<Spanner *> (unsmob_grob (smob));
 189   Link_array<Grob> heads (extract_grob_array (me, ly_symbol2scm ("note-heads")));
 190
 191   if (heads.is_empty ())
 192     return SCM_EOL;
 193
 194   // find size of note heads.
 195   Grob *staff = Staff_symbol_referencer::get_staff_symbol (me);
 196   if (!staff)
 197     return SCM_EOL;
 198
 199   Real length_fraction
 200     = robust_scm2double (me->get_property ("length-fraction"), 0.25);
 201
 202   Stencil ledgers;
 203   Stencil default_ledger;
 204
 205   Grob *common[NO_AXES];
 206
 207   for (int i = X_AXIS; i < NO_AXES; i++)
 208     {
 209       Axis a = Axis (i);
 210       common[a] = common_refpoint_of_array (heads, me, a);
 211       for (int i = heads.size (); i--;)
 212         if (Grob *g = unsmob_grob (me->get_property ("accidental-grob")))
 213           common[a] = common[a]->common_refpoint (g, a);
 214     }
 215
 216   int interspaces = Staff_symbol::line_count (staff) - 1;
 217   Ledger_requests reqs;
 218   for (int i = heads.size (); i--;)
 219     {
 220       Item *h = dynamic_cast<Item *> (heads[i]);
 221
 222       int pos = Staff_symbol_referencer::get_rounded_position (h);
 223       if (pos
 224           && abs (pos) > interspaces)
 225         {
 226           Interval head_extent = h->extent (common[X_AXIS], X_AXIS);
 227           Interval ledger_extent = head_extent;
 228           ledger_extent.widen (length_fraction * head_extent.length ());
 229
 230           Direction vdir = Direction (sign (pos));
 231           int rank = Paper_column::get_rank (h->get_column ());
 232
 233           reqs[rank][vdir].ledger_extent_.unite (ledger_extent);
 234           reqs[rank][vdir].head_extent_.unite (head_extent);
 235           reqs[rank][vdir].position_
 236             = vdir * ((vdir* reqs[rank][vdir].position_) >? (vdir *pos));
 237         }
 238     }
 239
 240   // determine maximum size for non-colliding ledger.
 241   Real gap = robust_scm2double (me->get_property ("gap"), 0.1);
 242   Ledger_requests::iterator last (reqs.end ());
 243   for (Ledger_requests::iterator i (reqs.begin ());
 244        i != reqs.end (); last = i++)
 245     {
 246       if (last == reqs.end ())
 247         {
 248           continue;
 249         }
 250
 251       Direction d = DOWN;
 252       do
 253         {
 254           if (abs (last->second[d].position_) > interspaces
 255               && abs (i->second[d].position_) > interspaces)
 256             {
 257               Real center
 258                 = (last->second[d].head_extent_[RIGHT]
 259                    + i->second[d].head_extent_[LEFT]) / 2;
 260
 261               Direction which = LEFT;
 262               do
 263                 {
 264                   Ledger_request &lr = ((which == LEFT) ? *last : *i).second[d];
 265
 266                   // due tilt of quarter note-heads
 267                   bool both
 268                     = (abs (last->second[d].position_) > interspaces + 1
 269                        && abs (i->second[d].position_) > interspaces + 1);
 270
 271                   Real limit = (center + (both? which * gap / 2 : 0));
 272                   lr.ledger_extent_.elem_ref (-which)
 273                     = which * (which * lr.ledger_extent_[-which] >? which * limit);
 274                 }
 275               while (flip (&which) != LEFT);
 276             }
 277         }
 278       while (flip (&d) != DOWN);
 279     }
 280
 281   // create  ledgers for note heads
 282   Real ledgerlinethickness
 283     = Staff_symbol::get_ledger_line_thickness (staff);
 284   Real halfspace = Staff_symbol::staff_space (staff) / 2;
 285   for (int i = heads.size (); i--;)
 286     {
 287       Item *h = dynamic_cast<Item *> (heads[i]);
 288
 289       int pos = Staff_symbol_referencer::get_rounded_position (h);
 290       if (abs (pos) > interspaces + 1)
 291         {
 292           Interval head_size = h->extent (common[X_AXIS], X_AXIS);
 293           Interval ledger_size = head_size;
 294           ledger_size.widen (ledger_size.length ()* length_fraction);
 295
 296           Interval max_size = reqs[Paper_column::get_rank (h->get_column ())][Direction (sign (pos))].ledger_extent_;
 297
 298           ledger_size.intersect (max_size);
 299           Real left_shorten = 0.0;
 300           if (Grob *g = unsmob_grob (h->get_property ("accidental-grob")))
 301             {
 302               Interval accidental_size = g->extent (common[X_AXIS], X_AXIS);
 303               Real d
 304                 = linear_combination (Drul_array<Real> (accidental_size[RIGHT],
 305                                                         head_size[LEFT]),
 306                                       0.0);
 307
 308               left_shorten = (-ledger_size[LEFT] + d) >? 0;
 309
 310               /*
 311                 TODO: shorten 2 ledger lines for the case natural +
 312                 downstem.
 313               */
 314
 315             }
 316
 317           ledgers.add_stencil (brew_ledger_lines (staff, pos, interspaces,
 318                                                   halfspace,
 319                                                   ledgerlinethickness,
 320                                                   ledger_size,
 321                                                   left_shorten));
 322         }
 323     }
 324
 325   ledgers.translate_axis (-me->relative_coordinate (common[X_AXIS], X_AXIS),
 326                           X_AXIS);
 327
 328   return ledgers.smobbed_copy ();
 329 }
 330
 331 ADD_INTERFACE (Ledger_line_spanner,
 332                "ledger-line-interface",
 333                "This spanner draws the ledger lines of a staff, for note heads that stick out. ",
 334                "note-heads thickness minimum-length-fraction length-fraction gap");
 335
 336 struct Ledgered_interface
 337 {
 338   static bool has_interface (Grob *);
 339 };
 340
 341 ADD_INTERFACE (Ledgered_interface,
 342                "ledgered-interface",
 343                "Objects that need ledger lines.",
 344                "no-ledgers");