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--2006 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 "warn.hh"
  25
  26 MAKE_SCHEME_CALLBACK (Rest_collision, force_shift_callback, 1);
  27 SCM
  28 Rest_collision::force_shift_callback (SCM smob)
  29 {
  30   Grob *them = unsmob_grob (smob);
  31   if (Note_column::has_rests (them))
  32     {
  33       Grob *collision = unsmob_grob (them->get_object ("rest-collision"));
  34
  35       if (collision)
  36         {
  37           (void) collision->get_property ("positioning-done");
  38         }
  39     }
  40   return scm_from_double (0.0);
  41 }
  42
  43 MAKE_SCHEME_CALLBACK_WITH_OPTARGS (Rest_collision, force_shift_callback_rest, 2, 1);
  44 SCM
  45 Rest_collision::force_shift_callback_rest (SCM rest, SCM offset)
  46 {
  47   Grob *rest_grob = unsmob_grob (rest);
  48   Grob *parent = rest_grob->get_parent (X_AXIS);
  49
  50   /*
  51     translate REST; we need the result of this translation later on,
  52     while the offset probably still is 0/calculation-in-progress.
  53    */
  54   if (scm_is_number (offset))
  55     rest_grob->translate_axis (scm_to_double (offset), Y_AXIS);
  56
  57   if (Note_column::has_interface (parent))
  58     force_shift_callback (parent->self_scm ());
  59
  60   return scm_from_double (0.0);
  61 }
  62
  63 void
  64 Rest_collision::add_column (Grob *me, Grob *p)
  65 {
  66   Pointer_group_interface::add_grob (me, ly_symbol2scm ("elements"), p);
  67
  68   /*
  69     only add callback for the rests, since we don't move anything
  70     else.
  71
  72     (not?)
  73   */
  74   add_offset_callback (p, Rest_collision::force_shift_callback_proc, Y_AXIS);
  75   p->set_object ("rest-collision", me->self_scm ());
  76
  77   Grob *rest = unsmob_grob (p->get_object ("rest"));
  78   if (rest)
  79     {
  80       chain_offset_callback (rest,
  81                              Rest_collision::force_shift_callback_rest_proc, Y_AXIS);
  82     }
  83 }
  84
  85 /*
  86   TODO: look at horizontal-shift to determine ordering between rests
  87   for more than two voices.
  88 */
  89 MAKE_SCHEME_CALLBACK(Rest_collision, calc_positioning_done, 1);
  90 SCM
  91 Rest_collision::calc_positioning_done (SCM smob)
  92 {
  93   Grob *me = unsmob_grob (smob);
  94   extract_grob_set (me, "elements", elts);
  95
  96   vector<Grob*> rests;
  97   vector<Grob*> notes;
  98
  99   for (vsize i = 0; i < elts.size (); i++)
 100     {
 101       Grob *e = elts[i];
 102       if (unsmob_grob (e->get_object ("rest")))
 103         {
 104           /*
 105             Ignore rests under beam.
 106           */
 107           Grob *st = unsmob_grob (e->get_object ("stem"));
 108           if (st && unsmob_grob (st->get_object ("beam")))
 109             continue;
 110
 111           rests.push_back (e);
 112         }
 113       else
 114         notes.push_back (e);
 115     }
 116
 117   /*
 118     handle rest-rest and rest-note collisions
 119
 120     [todo]
 121     * decide not to print rest if too crowded?
 122     */
 123
 124   /*
 125     no partners to collide with
 126   */
 127   if (rests.size () + notes.size () < 2)
 128     return SCM_UNSPECIFIED;
 129
 130   Real staff_space = Staff_symbol_referencer::staff_space (me);
 131   /*
 132     only rests
 133   */
 134   if (!notes.size ())
 135     {
 136
 137       /*
 138         This is incomplete: in case of an uneven number of rests, the
 139         center one should be centered on the staff.
 140       */
 141       Drul_array<vector<Grob*> > ordered_rests;
 142       for (vsize i = 0; i < rests.size (); i++)
 143         {
 144           Grob *r = Note_column::get_rest (rests[i]);
 145
 146           Direction d = get_grob_direction (r);
 147           if (d)
 148             ordered_rests[d].push_back (rests[i]);
 149           else
 150             rests[d]->warning (_ ("can't resolve rest collision: rest direction not set"));
 151         }
 152
 153       Direction d = LEFT;
 154       do
 155         vector_sort (ordered_rests[d], Note_column::shift_less);
 156       while (flip (&d) != LEFT)
 157         ;
 158
 159       do
 160         {
 161           if (ordered_rests[d].size () < 1)
 162             {
 163               if (ordered_rests[-d].size () > 1)
 164                 ordered_rests[-d][0]->warning (_ ("too many colliding rests"));
 165
 166               return SCM_UNSPECIFIED;
 167             }
 168         }
 169       while (flip (&d) != LEFT);
 170
 171       Grob *common = common_refpoint_of_array (ordered_rests[DOWN], me, Y_AXIS);
 172       common = common_refpoint_of_array (ordered_rests[UP], common, Y_AXIS);
 173
 174       Real diff
 175         = (ordered_rests[DOWN].back ()->extent (common, Y_AXIS)[UP]
 176            - ordered_rests[UP].back ()->extent (common, Y_AXIS)[DOWN]) / staff_space;
 177
 178       if (diff > 0)
 179         {
 180           int amount_down = (int) ceil (diff / 2);
 181           diff -= amount_down;
 182           Note_column::translate_rests (ordered_rests[DOWN].back (),
 183                                         -2 * amount_down);
 184           if (diff > 0)
 185             Note_column::translate_rests (ordered_rests[UP].back (),
 186                                           2 * int (ceil (diff)));
 187         }
 188
 189       do
 190         {
 191           for (vsize i = ordered_rests[d].size () -1; i-- > 0;)
 192             {
 193               Real last_y = ordered_rests[d][i + 1]->extent (common, Y_AXIS)[d];
 194               Real y = ordered_rests[d][i]->extent (common, Y_AXIS)[-d];
 195
 196               Real diff = d * ((last_y - y) / staff_space);
 197               if (diff > 0)
 198                 Note_column::translate_rests (ordered_rests[d][i], d * (int) ceil (diff) * 2);
 199             }
 200         }
 201       while (flip (&d) != LEFT);
 202     }
 203   else
 204     {
 205       /*
 206         Rests and notes.
 207       */
 208       if (rests.size () > 1)
 209         warning (_ ("too many colliding rests"));
 210       Grob *rcol = 0;
 211       Direction dir = CENTER;
 212
 213       for (vsize i = rests.size (); !rcol && i--;)
 214         if (Note_column::dir (rests[i]))
 215           {
 216             rcol = rests[i];
 217             dir = Note_column::dir (rcol);
 218           }
 219
 220       if (!rcol)
 221         return SCM_UNSPECIFIED;
 222
 223       Grob *rest = Note_column::get_rest (rcol);
 224       Grob *common = common_refpoint_of_array (notes, rcol, Y_AXIS);
 225
 226       Interval restdim = rcol->extent (common, Y_AXIS);
 227       if (restdim.is_empty ())
 228         return SCM_UNSPECIFIED;
 229
 230       Real staff_space = Staff_symbol_referencer::staff_space (rcol);
 231       Real minimum_dist = robust_scm2double (me->get_property ("minimum-distance"), 1.0) * staff_space;
 232
 233       Interval notedim;
 234       for (vsize i = 0; i < notes.size (); i++)
 235         notedim.unite (notes[i]->extent (common, Y_AXIS));
 236
 237
 238       Real y = dir * max (0.0,
 239                           -dir * restdim[-dir] + dir * notedim[dir]  + minimum_dist);
 240
 241       int stafflines = Staff_symbol_referencer::line_count (me);
 242       if (!stafflines)
 243         {
 244           programming_error ("no staff line count");
 245           stafflines = 5;
 246         }
 247
 248       // move discretely by half spaces.
 249       int discrete_y = dir * int (ceil (y / (0.5 * dir * staff_space)));
 250
 251       // move by whole spaces inside the staff.
 252       if (fabs (Staff_symbol_referencer::get_position (rest)
 253                 + discrete_y) < stafflines + 1)
 254         {
 255           discrete_y = dir * int (ceil (dir * discrete_y / 2.0) * 2.0);
 256         }
 257
 258       Note_column::translate_rests (rcol, discrete_y);
 259     }
 260   return SCM_UNSPECIFIED;
 261 }
 262
 263 ADD_INTERFACE (Rest_collision, "rest-collision-interface",
 264                "Move around ordinary rests (not multi-measure-rests) to avoid "
 265                "conflicts.",
 266
 267                /* properties */
 268                "minimum-distance "
 269                "positioning-done "
 270                "elements");
 271