lily/staff-spacing.cc

   1 /*
   2   staff-spacing.cc -- implement Staff_spacing
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2001--2006  Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "staff-spacing.hh"
  10
  11 #include <cstdio>
  12 using namespace std;
  13
  14 #include "paper-column.hh"
  15 #include "separation-item.hh"
  16 #include "warn.hh"
  17 #include "bar-line.hh"
  18 #include "staff-symbol-referencer.hh"
  19 #include "note-column.hh"
  20 #include "stem.hh"
  21 #include "accidental-placement.hh"
  22 #include "pointer-group-interface.hh"
  23 #include "directional-element-interface.hh"
  24
  25 /*
  26   Insert some more space for the next note, in case it has a stem in
  27   the wrong direction
  28 */
  29 void
  30 Staff_spacing::next_note_correction (Grob *me,
  31                                      Grob *g,
  32                                      Interval bar_size,
  33                                      Real *space,
  34                                      Real *fix)
  35 {
  36   (void)space;
  37
  38   if (!g || !Note_column::has_interface (g))
  39     return ;
  40
  41   Item *col = dynamic_cast<Item *> (g)->get_column ();
  42   Real max_corr = max (0., (- g->extent (col, X_AXIS)[LEFT]));
  43
  44   /*
  45     Duh. If this gets out of hand, we should invent something more generic.
  46   */
  47   if (Grob *a = Note_column::accidentals (g))
  48     {
  49       Interval v;
  50       if (Accidental_placement::has_interface (a))
  51         v = Accidental_placement::get_relevant_accidental_extent (a, col, me);
  52       else
  53         v = a->extent (col, X_AXIS);
  54
  55       max_corr = max (max_corr, (- v[LEFT]));
  56     }
  57   if (Grob *a = unsmob_grob (g->get_object ("arpeggio")))
  58     max_corr = max (max_corr, - a->extent (col, X_AXIS)[LEFT]);
  59
  60   /*
  61     Let's decrease the space a little if the problem is not located
  62     after a barline.
  63   */
  64   if (bar_size.is_empty ())
  65     max_corr *= 0.75;
  66
  67   if (!bar_size.is_empty ())
  68     if (Grob *stem = Note_column::get_stem (g))
  69       {
  70         Direction d = get_grob_direction (stem);
  71         if (d == DOWN)
  72           {
  73             Real stem_start = Stem::head_positions (stem) [DOWN];
  74             Real stem_end = Stem::stem_end_position (stem);
  75             Interval stem_posns (min (stem_start, stem_end),
  76                                  max (stem_end, stem_start));
  77
  78             stem_posns.intersect (bar_size);
  79
  80             Real corr = min (abs (stem_posns.length () / 7.0), 1.0);
  81             corr *= robust_scm2double (me->get_property ("stem-spacing-correction"), 1);
  82
  83             if (d != DOWN)
  84               corr = 0.0;
  85             max_corr = max (max_corr, corr);
  86           }
  87       }
  88
  89   *fix += max_corr;
  90 }
  91
  92 /*
  93   Y-positions that are covered by BAR_GROB, in the case that it is a
  94   barline.  */
  95 Interval
  96 Staff_spacing::bar_y_positions (Grob *bar_grob)
  97 {
  98   Interval bar_size;
  99   bar_size.set_empty ();
 100   if (Bar_line::has_interface (bar_grob))
 101     {
 102       SCM glyph = bar_grob->get_property ("glyph-name");
 103       Grob *staff_sym = Staff_symbol_referencer::get_staff_symbol (bar_grob);
 104
 105       string glyph_string = scm_is_string (glyph) ? ly_scm2string (glyph) : "";
 106       if (glyph_string.substr (0, 1) == "|"
 107           || glyph_string.substr (0, 1) == ".")
 108         {
 109           Grob *common = bar_grob->common_refpoint (staff_sym, Y_AXIS);
 110           Interval bar_size = bar_grob->extent (common, Y_AXIS);
 111           bar_size *= 1.0 / Staff_symbol_referencer::staff_space (bar_grob);
 112         }
 113     }
 114   return bar_size;
 115 }
 116
 117 /*
 118   Do corrections for the following notes.
 119
 120   This is slightly convoluted, since the staffspacing grob gets
 121   pointers to the separation-items, not the note-columns or
 122   note-spacings.
 123 */
 124 void
 125 Staff_spacing::next_notes_correction (Grob *me, Grob *last_grob,
 126                                       Real *compound_space, Real *compound_fixed
 127                                       )
 128 {
 129   Interval bar_size = bar_y_positions (last_grob);
 130
 131   extract_grob_set (me, "right-items", right_items);
 132
 133   *compound_fixed = 0.0;
 134   *compound_space = 0.0;
 135   int wish_count = 0;
 136
 137   for (vsize i = right_items.size (); i--;)
 138     {
 139       Grob *g = right_items[i];
 140
 141       Real space = 0.0;
 142       Real fixed = 0.0;
 143
 144       next_note_correction (me, g, bar_size, &space, &fixed);
 145
 146       *compound_space += space;
 147       *compound_fixed += fixed;
 148       wish_count ++;
 149
 150       extract_grob_set (g, "elements", elts);
 151       for (vsize j = elts.size (); j--;)
 152         {
 153           Real space = 0.0;
 154           Real fixed = 0.0;
 155           next_note_correction (me, elts[j], bar_size, &space, &fixed);
 156           *compound_fixed += fixed;
 157           *compound_space += space;
 158           wish_count ++;
 159         }
 160     }
 161
 162   if (wish_count)
 163     {
 164       *compound_space /= wish_count;
 165       *compound_fixed /= wish_count;
 166     }
 167 }
 168
 169 void
 170 Staff_spacing::get_spacing_params (Grob *me, Real *space, Real *fixed)
 171 {
 172   *space = 1.0;
 173   *fixed = 1.0;
 174
 175   Grob *separation_item = 0;
 176   Item *me_item = dynamic_cast<Item *> (me);
 177
 178   extract_grob_set (me, "left-items", items);
 179   for (vsize i = items.size (); i--;)
 180     {
 181       Grob *cand = items[i];
 182       if (cand && Separation_item::has_interface (cand))
 183         separation_item = cand;
 184     }
 185
 186   //  printf ("doing col %d\n" , Paper_column::get_rank (left_col));
 187   if (!separation_item)
 188     {
 189       programming_error ("no sep item");
 190       return;
 191     }
 192
 193   Interval last_ext;
 194   Grob *last_grob = Separation_item::extremal_break_aligned_grob (separation_item, RIGHT,
 195                                                                   &last_ext);
 196   if (!last_grob)
 197     {
 198       /*
 199         TODO:
 200
 201         Should  insert a adjustable space here? For excercises, you might want to
 202         use a staff without a clef in the beginning.
 203       */
 204
 205       /*
 206         we used to have a warning here, but it generates a lot of
 207         spurious error messages.
 208       */
 209       return;
 210     }
 211
 212   *fixed = last_ext[RIGHT];
 213   *space = *fixed + 1.0;
 214
 215   SCM alist = last_grob->get_property ("space-alist");
 216   if (!scm_list_p (alist))
 217     return;
 218
 219   SCM space_def = scm_sloppy_assq (ly_symbol2scm ("first-note"), alist);
 220   if (me_item->break_status_dir () == CENTER)
 221     {
 222       SCM nndef = scm_sloppy_assq (ly_symbol2scm ("next-note"), alist);
 223       if (scm_is_pair (nndef))
 224         space_def = nndef;
 225     }
 226
 227   if (!scm_is_pair (space_def))
 228     {
 229       programming_error ("unknown prefatory spacing");
 230       return;
 231     }
 232
 233   space_def = scm_cdr (space_def);
 234   Real distance = scm_to_double (scm_cdr (space_def));
 235   SCM type = scm_car (space_def);
 236
 237   *fixed = last_ext[RIGHT];
 238   if (type == ly_symbol2scm ("fixed-space"))
 239     {
 240       *fixed += distance;
 241       *space = *fixed;
 242     }
 243   else if (type == ly_symbol2scm ("extra-space"))
 244     *space = *fixed + distance;
 245   else if (type == ly_symbol2scm ("semi-fixed-space"))
 246     {
 247       *fixed += distance / 2;
 248       *space = *fixed + distance / 2;
 249     }
 250   else if (type == ly_symbol2scm ("minimum-space"))
 251     *space = last_ext[LEFT] + max (last_ext.length (), distance);
 252   else if (type == ly_symbol2scm ("minimum-fixed-space"))
 253     {
 254       *space = last_ext[LEFT] + max (last_ext.length (), distance);
 255       *fixed = *space;
 256     }
 257
 258   Real correction_fixed, correction_space;
 259   next_notes_correction (me, last_grob, &correction_space, &correction_fixed );
 260   *space += correction_space;
 261   *fixed += correction_fixed;
 262 }
 263
 264 ADD_INTERFACE (Staff_spacing, "staff-spacing-interface",
 265                "This object calculates spacing details from a "
 266                " breakable symbol (left) to another object. For example, it takes care "
 267                " of  optical spacing from  a bar lines to a note.",
 268
 269                /* properties */
 270                "stem-spacing-correction "
 271                "left-items "
 272                "right-items "
 273                );