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--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "rest-collision.hh"
  10
  11 #include <cmath>                // ceil.
  12 using namespace std;
  13
  14 #include "directional-element-interface.hh"
  15 #include "duration.hh"
  16 #include "international.hh"
  17 #include "note-column.hh"
  18 #include "output-def.hh"
  19 #include "pointer-group-interface.hh"
  20 #include "rest.hh"
  21 #include "rhythmic-head.hh"
  22 #include "staff-symbol-referencer.hh"
  23 #include "stem.hh"
  24 #include "grob.hh"
  25 #include "warn.hh"
  26
  27 MAKE_SCHEME_CALLBACK (Rest_collision, force_shift_callback, 1);
  28 SCM
  29 Rest_collision::force_shift_callback (SCM smob)
  30 {
  31   Grob *them = unsmob_grob (smob);
  32   if (Note_column::has_rests (them))
  33     {
  34       Grob *collision = unsmob_grob (them->get_object ("rest-collision"));
  35
  36       if (collision)
  37         {
  38           (void) collision->get_property ("positioning-done");
  39         }
  40     }
  41   return scm_from_double (0.0);
  42 }
  43
  44 MAKE_SCHEME_CALLBACK_WITH_OPTARGS (Rest_collision, force_shift_callback_rest, 2, 1, "");
  45 SCM
  46 Rest_collision::force_shift_callback_rest (SCM rest, SCM offset)
  47 {
  48   Grob *rest_grob = unsmob_grob (rest);
  49   Grob *parent = rest_grob->get_parent (X_AXIS);
  50
  51   /*
  52     translate REST; we need the result of this translation later on,
  53     while the offset probably still is 0/calculation-in-progress.
  54    */
  55   if (scm_is_number (offset))
  56     rest_grob->translate_axis (scm_to_double (offset), Y_AXIS);
  57
  58   if (Note_column::has_interface (parent))
  59     force_shift_callback (parent->self_scm ());
  60
  61   return scm_from_double (0.0);
  62 }
  63
  64 void
  65 Rest_collision::add_column (Grob *me, Grob *p)
  66 {
  67   Pointer_group_interface::add_grob (me, ly_symbol2scm ("elements"), p);
  68
  69   /*
  70     only add callback for the rests, since we don't move anything
  71     else.
  72
  73     (not?)
  74   */
  75   add_offset_callback (p, Rest_collision::force_shift_callback_proc, Y_AXIS);
  76   p->set_object ("rest-collision", me->self_scm ());
  77
  78   Grob *rest = unsmob_grob (p->get_object ("rest"));
  79   if (rest)
  80     {
  81       chain_offset_callback (rest,
  82                              Rest_collision::force_shift_callback_rest_proc, Y_AXIS);
  83     }
  84 }
  85
  86 /*
  87   TODO: look at horizontal-shift to determine ordering between rests
  88   for more than two voices.
  89 */
  90 MAKE_SCHEME_CALLBACK (Rest_collision, calc_positioning_done, 1);
  91 SCM
  92 Rest_collision::calc_positioning_done (SCM smob)
  93 {
  94   Grob *me = unsmob_grob (smob);
  95
  96   me->set_property ("positioning-done", SCM_BOOL_T);
  97
  98   extract_grob_set (me, "elements", elts);
  99
 100   vector<Grob*> rests;
 101   vector<Grob*> notes;
 102
 103   for (vsize i = 0; i < elts.size (); i++)
 104     {
 105       Grob *e = elts[i];
 106       if (unsmob_grob (e->get_object ("rest")))
 107         rests.push_back (e);
 108       else
 109         notes.push_back (e);
 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
 119   /*
 120     no partners to collide with
 121   */
 122   if (rests.size () + notes.size () < 2)
 123     return SCM_BOOL_T;
 124
 125   Real staff_space = Staff_symbol_referencer::staff_space (me);
 126   /*
 127     only rests
 128   */
 129   if (!notes.size ())
 130     {
 131
 132       /*
 133         This is incomplete: in case of an uneven number of rests, the
 134         center one should be centered on the staff.
 135       */
 136       Drul_array<vector<Grob*> > ordered_rests;
 137       for (vsize i = 0; i < rests.size (); i++)
 138         {
 139           Grob *r = Note_column::get_rest (rests[i]);
 140
 141           Direction d = get_grob_direction (r);
 142           if (d)
 143             ordered_rests[d].push_back (rests[i]);
 144           else
 145             rests[d]->warning (_ ("cannot resolve rest collision: rest direction not set"));
 146         }
 147
 148       Direction d = LEFT;
 149       do
 150         vector_sort (ordered_rests[d], Note_column::shift_less);
 151       while (flip (&d) != LEFT)
 152         ;
 153
 154       do
 155         {
 156           if (ordered_rests[d].size () < 1)
 157             {
 158               if (ordered_rests[-d].size () > 1)
 159                 ordered_rests[-d][0]->warning (_ ("too many colliding rests"));
 160
 161               return SCM_BOOL_T;
 162             }
 163         }
 164       while (flip (&d) != LEFT);
 165
 166       Grob *common = common_refpoint_of_array (ordered_rests[DOWN], me, Y_AXIS);
 167       common = common_refpoint_of_array (ordered_rests[UP], common, Y_AXIS);
 168
 169       Real diff
 170         = (ordered_rests[DOWN].back ()->extent (common, Y_AXIS)[UP]
 171            - ordered_rests[UP].back ()->extent (common, Y_AXIS)[DOWN]) / staff_space;
 172
 173       if (diff > 0)
 174         {
 175           int amount_down = (int) ceil (diff / 2);
 176           diff -= amount_down;
 177           Note_column::translate_rests (ordered_rests[DOWN].back (),
 178                                         -2 * amount_down);
 179           if (diff > 0)
 180             Note_column::translate_rests (ordered_rests[UP].back (),
 181                                           2 * int (ceil (diff)));
 182         }
 183
 184       do
 185         {
 186           for (vsize i = ordered_rests[d].size () -1; i-- > 0;)
 187             {
 188               Real last_y = ordered_rests[d][i + 1]->extent (common, Y_AXIS)[d];
 189               Real y = ordered_rests[d][i]->extent (common, Y_AXIS)[-d];
 190
 191               Real diff = d * ((last_y - y) / staff_space);
 192               if (diff > 0)
 193                 Note_column::translate_rests (ordered_rests[d][i], d * (int) ceil (diff) * 2);
 194             }
 195         }
 196       while (flip (&d) != LEFT);
 197     }
 198   else
 199     {
 200       /*
 201         Rests and notes.
 202       */
 203       if (rests.size () > 1)
 204         warning (_ ("too many colliding rests"));
 205       Grob *rcol = 0;
 206       Direction dir = CENTER;
 207
 208       for (vsize i = rests.size (); !rcol && i--;)
 209         if (Note_column::dir (rests[i]))
 210           {
 211             rcol = rests[i];
 212             dir = Note_column::dir (rcol);
 213           }
 214
 215       if (!rcol)
 216         return SCM_BOOL_T;
 217
 218       Grob *rest = Note_column::get_rest (rcol);
 219       Grob *common = common_refpoint_of_array (notes, rcol, Y_AXIS);
 220
 221       Interval restdim = rcol->extent (common, Y_AXIS);
 222       if (restdim.is_empty ())
 223         return SCM_BOOL_T;
 224
 225       Real staff_space = Staff_symbol_referencer::staff_space (rcol);
 226       Real minimum_dist = robust_scm2double (me->get_property ("minimum-distance"), 1.0) * staff_space;
 227
 228       Interval notedim;
 229       for (vsize i = 0; i < notes.size (); i++)
 230         {
 231           if (Note_column::dir (notes[i]) == -dir)
 232             {
 233               /* try not to look at the stem, as looking at a beamed
 234                  note may trigger beam positioning prematurely.
 235
 236                  This happens with dotted rests, which need Y
 237                  positioning to compute X-positioning.
 238               */
 239               Grob *head = Note_column::first_head (notes[i]);
 240               if (head)
 241                 notedim.unite (head->extent (common, Y_AXIS));
 242               else
 243                 programming_error ("Note_column without first_head()");
 244             }
 245           else
 246             notedim.unite (notes[i]->extent (common, Y_AXIS));
 247         }
 248
 249       Real y = dir * max (0.0,
 250                           -dir * restdim[-dir] + dir * notedim[dir]  + minimum_dist);
 251
 252       int stafflines = Staff_symbol_referencer::line_count (me);
 253       if (!stafflines)
 254         {
 255           programming_error ("no staff line count");
 256           stafflines = 5;
 257         }
 258
 259       // move discretely by half spaces.
 260       int discrete_y = dir * int (ceil (y / (0.5 * dir * staff_space)));
 261
 262       // move by whole spaces inside the staff.
 263       if (fabs (Staff_symbol_referencer::get_position (rest)
 264                 + discrete_y) < stafflines + 1)
 265         {
 266           discrete_y = dir * int (ceil (dir * discrete_y / 2.0) * 2.0);
 267         }
 268
 269       Note_column::translate_rests (rcol, discrete_y);
 270     }
 271   return SCM_BOOL_T;
 272 }
 273
 274 ADD_INTERFACE (Rest_collision,
 275                "Move around ordinary rests (not multi-measure-rests) to avoid"
 276                " conflicts.",
 277
 278                /* properties */
 279                "minimum-distance "
 280                "positioning-done "
 281                "elements "
 282                );
 283