lily/rest-collision.cc

   1 /*
   2   rest-collision.cc -- implement Rest_collision
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8
   9 #include <math.h>               // ceil.
  10
  11 #include "warn.hh"
  12 #include "rest-collision.hh"
  13 #include "note-column.hh"
  14 #include "stem.hh"
  15 #include "rhythmic-head.hh"
  16 #include "output-def.hh"
  17 #include "rest.hh"
  18 #include "group-interface.hh"
  19 #include "staff-symbol-referencer.hh"
  20 #include "duration.hh"
  21 #include "directional-element-interface.hh"
  22
  23 MAKE_SCHEME_CALLBACK (Rest_collision,force_shift_callback,2);
  24 SCM
  25 Rest_collision::force_shift_callback (SCM element_smob, SCM axis)
  26 {
  27   Grob *them = unsmob_grob (element_smob);
  28   Axis a = (Axis) ly_scm2int (axis);
  29   assert (a == Y_AXIS);
  30
  31   Grob * rc = unsmob_grob (them->get_property ("rest-collision"));
  32
  33   if (rc && !to_boolean (rc->get_property ("positioning-done")))
  34     {
  35       rc->set_property ("positioning-done", SCM_BOOL_T);
  36
  37       do_shift (rc);
  38     }
  39
  40   return scm_make_real (0.0);
  41 }
  42
  43
  44
  45 void
  46 Rest_collision::add_column (Grob*me,Grob *p)
  47 {
  48   me->add_dependency (p);
  49   Pointer_group_interface::add_grob (me, ly_symbol2scm ("elements"), p);
  50
  51   /*
  52     only add callback for the rests, since we don't move anything
  53     else.
  54
  55     (not?)
  56   */
  57   p->add_offset_callback (Rest_collision::force_shift_callback_proc, Y_AXIS);
  58   p->set_property ("rest-collision", me->self_scm ());
  59 }
  60
  61
  62 /*
  63   Combination of dot-count and duration-log.
  64  */
  65 static SCM
  66 head_characteristic (Grob * col)
  67 {
  68   Grob * s = unsmob_grob (col->get_property ("rest"));
  69
  70   if (!s)
  71     return SCM_BOOL_F;
  72   else
  73     return scm_cons (s->get_property ("duration-log"),
  74                     scm_int2num (Rhythmic_head::dot_count (s)));
  75 }
  76
  77 /*
  78   TODO: look at horizontal-shift to determine ordering between rests
  79   for more than two voices.
  80
  81  */
  82 SCM
  83 Rest_collision::do_shift (Grob *me)
  84 {
  85   SCM elts = me->get_property ("elements");
  86
  87   Link_array<Grob> rests;
  88   Link_array<Grob> notes;
  89
  90   for (SCM s = elts; ly_c_pair_p (s); s = ly_cdr (s))
  91     {
  92       Grob * e = unsmob_grob (ly_car (s));
  93       if (unsmob_grob (e->get_property ("rest")))
  94         {
  95           /*
  96             Ignore rests under beam.
  97            */
  98           Grob* st = unsmob_grob (e->get_property ("stem"));
  99           if (st && unsmob_grob (st->get_property ("beam")))
 100             continue;
 101
 102           rests.push (e);
 103         }
 104       else
 105         notes.push (e);
 106     }
 107
 108
 109   /*
 110      handle rest-rest and rest-note collisions
 111
 112      [todo]
 113      * decide not to print rest if too crowded?
 114    */
 115
 116   /*
 117     no partners to collide with
 118    */
 119   if (rests.size () + notes.size () < 2)
 120     return SCM_UNSPECIFIED;
 121
 122
 123   Real staff_space = Staff_symbol_referencer::staff_space (me);
 124   /*
 125     only rests
 126   */
 127   if (!notes.size ())
 128     {
 129
 130       /*
 131         This is incomplete: in case of an uneven number of rests, the
 132         center one should be centered on the staff.
 133        */
 134       Drul_array< Link_array <Grob > > ordered_rests;
 135       for (int i= 0; i < rests.size (); i++)
 136         {
 137           Grob * r = Note_column::get_rest (rests[i]);
 138
 139           Direction d = get_grob_direction (r);
 140           if (d)
 141             {
 142               ordered_rests[d].push (rests[i]);
 143             }
 144           else
 145             rests[d]->warning (_("rest direction not set.  Cannot resolve collision."));
 146         }
 147
 148       Direction d =  LEFT;
 149       do {
 150         ordered_rests[d].sort (Note_column::shift_compare);
 151       } while (flip (&d) != LEFT);
 152
 153       do {
 154         if (ordered_rests[d].size () < 1)
 155           {
 156             if (ordered_rests[-d].size() > 1)
 157               ordered_rests[-d][0]->warning (_("Too many colliding rests."));
 158
 159             return SCM_UNSPECIFIED;
 160           }
 161       } while (flip (&d) != LEFT);
 162
 163       Grob *common = common_refpoint_of_array (ordered_rests[DOWN], me, Y_AXIS);
 164       common =  common_refpoint_of_array (ordered_rests[UP], common, Y_AXIS);
 165
 166       Real diff =
 167         (ordered_rests[DOWN].top ()->extent (common, Y_AXIS)[UP]
 168          - ordered_rests[UP].top ()->extent (common, Y_AXIS)[DOWN]) /staff_space;
 169
 170       if (diff > 0)
 171         {
 172           int amount_down = (int) ceil (diff / 2);
 173           diff -= amount_down;
 174           Note_column::translate_rests (ordered_rests[DOWN].top (),
 175                                         -2 * amount_down);
 176           if (diff > 0)
 177             Note_column::translate_rests (ordered_rests[UP].top (),
 178                                           2 * int (ceil (diff)));
 179         }
 180
 181       do {
 182         for (int i = ordered_rests[d].size () -1; i-- > 0;)
 183           {
 184             Real last_y = ordered_rests[d][i+1]->extent (common, Y_AXIS)[d];
 185             Real y = ordered_rests[d][i]->extent (common, Y_AXIS)[-d];
 186
 187             Real diff = d * ((last_y - y) /staff_space);
 188             if (diff > 0)
 189               Note_column::translate_rests (ordered_rests[d][i],d * (int) ceil (diff) * 2);
 190           }
 191       } while (flip (&d) != LEFT);
 192     }
 193   else
 194     {
 195       /*
 196         Rests and notes.
 197        */
 198       if (rests.size () > 1)
 199         {
 200           warning (_ ("too many colliding rests"));
 201         }
 202       Grob * rcol = 0;
 203       Direction dir = CENTER;
 204
 205       for (int i= rests.size (); !rcol && i--;)
 206         if (Note_column::dir (rests[i]))
 207           {
 208             dir = Note_column::dir (rests[i]);
 209             rcol = rests[i];
 210           }
 211
 212       if (!rcol)
 213         return SCM_UNSPECIFIED;
 214
 215       Grob *common = common_refpoint_of_array (notes, rcol, Y_AXIS);
 216
 217       Interval restdim = rcol->extent (common, Y_AXIS);
 218       if (restdim.is_empty ())
 219         return SCM_UNSPECIFIED;
 220
 221       Real staff_space = Staff_symbol_referencer::staff_space (rcol);
 222       Real minimum_dist = robust_scm2double (me->get_property ("minimum-distance"), 1.0) * staff_space;
 223
 224       Interval notedim;
 225       for (int i = 0; i < notes.size (); i++)
 226         {
 227           notedim.unite (notes[i]->extent (common, Y_AXIS));
 228         }
 229
 230       Real dist =
 231         minimum_dist +  dir * (notedim[dir] - restdim[-dir]) >? 0;
 232
 233       int stafflines = Staff_symbol_referencer::line_count (me);
 234       if (!stafflines)
 235         {
 236           programming_error ("No staff line count ? ");
 237           stafflines =5;
 238         }
 239
 240       // move discretely by half spaces.
 241       int discrete_dist = int (ceil (dist / (0.5 *staff_space)));
 242
 243       // move by whole spaces inside the staff.
 244       if (discrete_dist < stafflines+1)
 245         discrete_dist = int (ceil (discrete_dist / 2.0)* 2.0);
 246
 247       Note_column::translate_rests (rcol,dir * discrete_dist);
 248     }
 249   return SCM_UNSPECIFIED;
 250 }
 251
 252
 253 ADD_INTERFACE (Rest_collision,"rest-collision-interface",
 254                "Move around ordinary rests (not multi-measure-rests) to avoid "
 255                "conflicts.",
 256                "minimum-distance positioning-done elements");
 257