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--2001 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8
   9 #include <math.h>               // ceil.
  10
  11 #include "debug.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       SCM elts = rc->get_grob_property ("elements");
  38       rc->set_grob_property ("elements", SCM_EOL);
  39
  40       do_shift (rc, elts);
  41     }
  42
  43   return gh_double2scm (0.0);
  44 }
  45
  46 void
  47 Rest_collision::add_column (Grob*me,Grob *p)
  48 {
  49   me->add_dependency (p);
  50   Pointer_group_interface::add_element (me, "elements", p);
  51
  52   /*
  53     only add callback for the rests, since we don't move anything else.
  54
  55  (not?)
  56   */
  57   p->add_offset_callback (Rest_collision::force_shift_callback_proc, Y_AXIS);
  58   p->set_grob_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_grob_property ("rest"));
  69
  70   if (!s)
  71     return SCM_BOOL_F;
  72   else
  73     return gh_cons (s->get_grob_property ("duration-log"),
  74                     gh_int2scm (Rhythmic_head::dot_count (s)));
  75 }
  76
  77 /*
  78   TODO: fixme, fucks up if called twice on the same set of rests.
  79
  80   TODO: look at horizontal-shift to determine ordering between rests
  81   for more than two voices.
  82
  83  */
  84 SCM
  85 Rest_collision::do_shift (Grob *me, SCM elts)
  86 {
  87   /*
  88     ugh. -> score  elt type
  89    */
  90   Link_array<Grob> rests;
  91   Link_array<Grob> notes;
  92   Grob * commony = 0;
  93   for (SCM s = elts; gh_pair_p (s); s = gh_cdr (s))
  94     {
  95
  96       Grob * e = unsmob_grob (gh_car (s));
  97       if (!e)
  98         continue;
  99
 100       if (!commony)
 101         commony = e;
 102       else
 103         commony= commony->common_refpoint (e, Y_AXIS);
 104
 105       if (unsmob_grob (e->get_grob_property ("rest")))
 106         rests.push (e);
 107       else
 108         notes.push (e);
 109     }
 110
 111
 112   /*
 113      handle rest-rest and rest-note collisions
 114
 115      [todo]
 116      * decide not to print rest if too crowded?
 117
 118      * ignore rests under beams.
 119    */
 120
 121   // no rests to collide
 122   if (!rests.size ())
 123     return SCM_UNSPECIFIED;
 124
 125   // no partners to collide with
 126   if (rests.size () + notes.size () < 2)
 127     return SCM_UNSPECIFIED;
 128
 129   // meisjes met meisjes
 130   if (!notes.size ())
 131     {
 132       SCM characteristic = head_characteristic (rests[0]);
 133       int i = 1;
 134       for (; i < rests.size (); i++)
 135         {
 136           if (!gh_equal_p (head_characteristic (rests[i]), characteristic))
 137             break;
 138         }
 139
 140       /*
 141         If all durations are the same, we'll check if there are more
 142         rests than maximum-rest-count.
 143         Otherwise (different durations), we'll try to display them all
 144  (urg: all 3 of them, currently).
 145        */
 146       int display_count;
 147       SCM s = me->get_grob_property ("maximum-rest-count");
 148       if (i == rests.size ()
 149           && gh_number_p (s) && gh_scm2int (s) < rests.size ())
 150         {
 151           display_count = gh_scm2int (s);
 152           for (; i > display_count; i--)
 153             {
 154               Grob* r = unsmob_grob (rests[i-1]->get_grob_property ("rest"));
 155               if (r)
 156                 r->suicide ();
 157               rests[i-1]->suicide ();
 158             }
 159         }
 160       else
 161         display_count = rests.size ();
 162
 163       /*
 164         Ugh. Should have minimum dist.
 165
 166         Ugh. What do we do if we have three different rests?
 167
 168        */
 169       int dy = display_count > 2 ? 6 : 4; // FIXME Should get dims from table.
 170       if (display_count > 1)
 171         {
 172           Direction d0 = Note_column::dir (rests[0]);
 173           Direction d1 = Note_column::dir (rests[1]);
 174
 175           if (!d0 && !d1)
 176             {
 177               d0= UP;
 178               d1 = DOWN;
 179             }
 180           else if (!d0)
 181             d0 = - d1;
 182           else if (!d1)
 183             d1 = -d0;
 184
 185           Note_column::translate_rests (rests[0],d0 *dy);
 186           Note_column::translate_rests (rests[1], d1 *dy);
 187         }
 188     }
 189   // meisjes met jongetjes
 190   else
 191     {
 192       if (rests.size () > 1)
 193         {
 194           warning (_ ("too many colliding rests"));
 195         }
 196       if (notes.size () > 1)
 197         {
 198           warning (_ ("too many notes for rest collision"));
 199         }
 200       Grob * rcol = rests[0];
 201
 202       // try to be opposite of noteheads.
 203       Direction dir = - Note_column::dir (notes[0]);
 204
 205       Grob * r = unsmob_grob (rcol->get_grob_property ("rest"));
 206       Interval restdim = r->extent (r, Y_AXIS); // ??
 207
 208       if (restdim.empty_b ())
 209         return SCM_UNSPECIFIED;
 210
 211       // FIXME: staff ref'd?
 212       Real staff_space = 1.0;
 213
 214       Real minimum_dist = gh_scm2double (me->get_grob_property ("minimum-distance")) * staff_space;
 215
 216       /*
 217         assumption: ref points are the same.
 218        */
 219       Interval notedim;
 220       for (int i = 0; i < notes.size (); i++)
 221         {
 222           Grob * stem = Note_column::stem_l (notes[i]);
 223           Grob * head = Stem::first_head (stem);
 224           notedim.unite (head->extent (commony, Y_AXIS));
 225         }
 226
 227       Interval inter (notedim);
 228       inter.intersect (restdim);
 229
 230       Real dist =
 231         minimum_dist +  dir * (notedim[dir] - restdim[-dir]) >? 0;
 232
 233
 234       // FIXME
 235       //int stafflines = 5; // rcol->rests[0]->line_count;
 236       int stafflines = Staff_symbol_referencer::line_count (me);
 237       // hurg?
 238       stafflines = stafflines != 0 ? stafflines : 5;
 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 void
 253 Rest_collision::set_interface (Grob*me)
 254 {
 255   me->set_extent_callback (SCM_EOL, X_AXIS);
 256   me->set_extent_callback (SCM_EOL, Y_AXIS);
 257 }
 258