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--2002 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 "paper-def.hh"
  17 #include "rest.hh"
  18 #include "group-interface.hh"
  19 #include "staff-symbol-referencer.hh"
  20 #include "duration.hh"
  21
  22 MAKE_SCHEME_CALLBACK (Rest_collision,force_shift_callback,2);
  23 SCM
  24 Rest_collision::force_shift_callback (SCM element_smob, SCM axis)
  25 {
  26   Grob *them = unsmob_grob (element_smob);
  27   Axis a = (Axis) gh_scm2int (axis);
  28   assert (a == Y_AXIS);
  29
  30   Grob * rc = unsmob_grob (them->get_grob_property ("rest-collision"));
  31
  32   if (rc)
  33     {
  34       /*
  35         Done: destruct pointers, so we do the shift only once.
  36
  37         TODO: use rest-collision-done
  38       */
  39       SCM elts = rc->get_grob_property ("elements");
  40       rc->set_grob_property ("elements", SCM_EOL);
  41
  42       do_shift (rc, elts);
  43     }
  44
  45   return gh_double2scm (0.0);
  46 }
  47
  48 void
  49 Rest_collision::add_column (Grob*me,Grob *p)
  50 {
  51   me->add_dependency (p);
  52   Pointer_group_interface::add_grob (me, ly_symbol2scm ("elements"), p);
  53
  54   /*
  55     only add callback for the rests, since we don't move anything else.
  56
  57  (not?)
  58   */
  59   p->add_offset_callback (Rest_collision::force_shift_callback_proc, Y_AXIS);
  60   p->set_grob_property ("rest-collision", me->self_scm ());
  61 }
  62
  63
  64 /*
  65   Combination of dot-count and duration-log.
  66  */
  67 static SCM
  68 head_characteristic (Grob * col)
  69 {
  70   Grob * s = unsmob_grob (col->get_grob_property ("rest"));
  71
  72   if (!s)
  73     return SCM_BOOL_F;
  74   else
  75     return gh_cons (s->get_grob_property ("duration-log"),
  76                     gh_int2scm (Rhythmic_head::dot_count (s)));
  77 }
  78
  79 /*
  80   TODO: fixme, fucks up if called twice on the same set of rests.
  81
  82   TODO: look at horizontal-shift to determine ordering between rests
  83   for more than two voices.
  84  */
  85 SCM
  86 Rest_collision::do_shift (Grob *me, SCM elts)
  87 {
  88   /*
  89     ugh. -> score  elt type
  90    */
  91   Link_array<Grob> rests;
  92   Link_array<Grob> notes;
  93
  94   for (SCM s = elts; gh_pair_p (s); s = ly_cdr (s))
  95     {
  96       Grob * e = unsmob_grob (ly_car (s));
  97       if (unsmob_grob (e->get_grob_property ("rest")))
  98         rests.push (e);
  99       else
 100         notes.push (e);
 101     }
 102
 103
 104   /*
 105      handle rest-rest and rest-note collisions
 106
 107      [todo]
 108      * decide not to print rest if too crowded?
 109
 110      * ignore rests under beams.
 111    */
 112
 113   // no rests to collide
 114   if (!rests.size ())
 115     return SCM_UNSPECIFIED;
 116
 117   // no partners to collide with
 118   if (rests.size () + notes.size () < 2)
 119     return SCM_UNSPECIFIED;
 120
 121   // meisjes met meisjes
 122   if (!notes.size ())
 123     {
 124       SCM characteristic = head_characteristic (rests[0]);
 125       int i = 1;
 126       for (; i < rests.size (); i++)
 127         {
 128           if (!gh_equal_p (head_characteristic (rests[i]), characteristic))
 129             break;
 130         }
 131
 132       /*
 133         If all durations are the same, we'll check if there are more
 134         rests than maximum-rest-count.
 135         Otherwise (different durations), we'll try to display them all
 136  (urg: all 3 of them, currently).
 137        */
 138       int display_count;
 139       SCM s = me->get_grob_property ("maximum-rest-count");
 140       if (i == rests.size ()
 141           && gh_number_p (s) && gh_scm2int (s) < rests.size ())
 142         {
 143           display_count = gh_scm2int (s);
 144           for (; i > display_count; i--)
 145             {
 146               Grob* r = unsmob_grob (rests[i-1]->get_grob_property ("rest"));
 147               if (r)
 148                 {
 149                   Grob * d = unsmob_grob (r->get_grob_property ("dot"));
 150                   if (d)
 151                     d->suicide();
 152                   r->suicide ();
 153                 }
 154               rests[i-1]->suicide ();
 155             }
 156         }
 157       else
 158         display_count = rests.size ();
 159
 160       /*
 161         Ugh. Should have minimum dist.
 162
 163         Ugh. What do we do if we have three different rests?
 164
 165        */
 166       int dy = display_count > 2 ? 6 : 4; // FIXME Should get dims from table.
 167       if (display_count > 1)
 168         {
 169           Direction d0 = Note_column::dir (rests[0]);
 170           Direction d1 = Note_column::dir (rests[1]);
 171
 172           if (!d0 && !d1)
 173             {
 174               d0= UP;
 175               d1 = DOWN;
 176             }
 177           else if (!d0)
 178             d0 = - d1;
 179           else if (!d1)
 180             d1 = -d0;
 181
 182           Note_column::translate_rests (rests[0],d0 *dy);
 183           Note_column::translate_rests (rests[1], d1 *dy);
 184         }
 185     }
 186   // meisjes met jongetjes
 187   else
 188     {
 189       if (rests.size () > 1)
 190         {
 191           warning (_ ("too many colliding rests"));
 192         }
 193       Grob * rcol = rests[0];
 194       Direction dir = Note_column::dir (rests[0]);
 195
 196       if (!dir)
 197         {
 198           dir = - Note_column::dir (notes[0]);
 199         }
 200       Grob * r = unsmob_grob (rcol->get_grob_property ("rest"));
 201       Interval restdim = r->extent (r, Y_AXIS); // ??
 202
 203       if (restdim.empty_b ())
 204         return SCM_UNSPECIFIED;
 205
 206
 207       Real staff_space = Staff_symbol_referencer::staff_space (rcol);
 208
 209       Real minimum_dist = gh_scm2double (me->get_grob_property ("minimum-distance")) * staff_space;
 210
 211
 212       Grob *common = common_refpoint_of_array (notes, rcol, Y_AXIS);
 213
 214       Interval notedim;
 215       for (int i = 0; i < notes.size (); i++)
 216         {
 217           notedim.unite (notes[i]->extent (common, Y_AXIS));
 218         }
 219
 220       Interval inter (notedim);
 221       inter.intersect (restdim);
 222
 223       Real dist =
 224         minimum_dist +  dir * (notedim[dir] - restdim[-dir]) >? 0;
 225
 226       int stafflines = Staff_symbol_referencer::line_count (me);
 227       if (!stafflines)
 228         {
 229           programming_error ("No staff line count ? ");
 230           stafflines =5;
 231         }
 232
 233       // move discretely by half spaces.
 234       int discrete_dist = int (ceil (dist / (0.5 *staff_space)));
 235
 236       // move by whole spaces inside the staff.
 237       if (discrete_dist < stafflines+1)
 238         discrete_dist = int (ceil (discrete_dist / 2.0)* 2.0);
 239
 240       Note_column::translate_rests (rcol,dir * discrete_dist);
 241     }
 242   return SCM_UNSPECIFIED;
 243 }
 244
 245
 246 ADD_INTERFACE (Rest_collision,"rest-collision-interface",
 247   "Move around ordinary rests (not multi-measure-rests) to avoid
 248 conflicts.",
 249   "maximum-rest-count minimum-distance elements");
 250