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--2004  Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8 */
   9 #include <stdio.h>
  10
  11 #include "paper-column.hh"
  12 #include "separation-item.hh"
  13 #include "item.hh"
  14 #include "staff-spacing.hh"
  15 #include "grob.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
  23 /*
  24   Insert some more space for the next note, in case it has a stem in
  25   the wrong direction
  26
  27  */
  28 Real
  29 Staff_spacing::next_note_correction (Grob * me,
  30                                      Grob * g,
  31                                      Interval bar_size)
  32 {
  33   if (!g || !Note_column::has_interface (g))
  34     return 0.0;
  35
  36   Item *col =dynamic_cast<Item*> (g)->get_column ();
  37   Real max_corr = 0. >? (- g->extent (col, X_AXIS)[LEFT]);
  38
  39   /*
  40     Duh. If this gets out of hand, we should invent something more generic.
  41    */
  42   if (Grob * a = Note_column::accidentals (g))
  43     {
  44       Interval v;
  45       if (Accidental_placement::has_interface (a))
  46         {
  47           v = Accidental_placement::get_relevant_accidental_extent (a, col, me);
  48         }
  49       else
  50         v = a->extent (col, X_AXIS);
  51
  52       max_corr = max_corr >? (- v[LEFT]);
  53     }
  54   if (Grob* a = unsmob_grob (g->get_property ("arpeggio")))
  55     {
  56       max_corr = max_corr >? (- a->extent (col, X_AXIS)[LEFT]);
  57     }
  58
  59   /*
  60     Let's decrease the space a little if the problem is not located
  61     after a barline.
  62   */
  63   if (bar_size.is_empty ())
  64     max_corr *= 0.75;
  65
  66   if (!bar_size.is_empty ())
  67     if (Grob *stem = Note_column::get_stem (g))
  68       {
  69         Direction d = Stem::get_direction (stem);
  70         if (d == DOWN)
  71           {
  72             Real stem_start = Stem::head_positions (stem) [DOWN];
  73             Real stem_end = Stem::stem_end_position (stem);
  74             Interval stem_posns (stem_start <? stem_end,
  75                                  stem_end >? stem_start);
  76
  77             stem_posns.intersect (bar_size);
  78
  79             Real corr = abs (stem_posns.length ()/7.) <? 1.0;
  80             corr *=
  81               robust_scm2double (me->get_property ("stem-spacing-correction"), 1);
  82
  83             if (d != DOWN)
  84               corr = 0.0;
  85             max_corr = max_corr >? corr;
  86           }
  87       }
  88   return max_corr;
  89 }
  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");
 103
 104       String glyph_string = gh_string_p (glyph) ? ly_scm2string (glyph) : "";
 105       if (glyph_string.left_string (1) == "|" || glyph_string.left_string (1) == ".")
 106         {
 107           SCM sz = Bar_line::get_staff_bar_size (bar_grob->self_scm ());
 108           bar_size = Interval (-1,1);
 109           bar_size *= robust_scm2double (sz, 1)
 110             / Staff_symbol_referencer::staff_space (bar_grob);
 111         }
 112     }
 113   return bar_size;
 114 }
 115
 116 /*
 117   Do corrections for the following notes.
 118
 119   This is slightly convoluted, since the staffspacing grob gets
 120   pointers to the separation-items, not the note-columns or
 121   note-spacings.
 122
 123  */
 124 Real
 125 Staff_spacing::next_notes_correction (Grob *me, Grob * last_grob)
 126 {
 127   Interval bar_size = bar_y_positions (last_grob);
 128   Real max_corr =0.0;
 129
 130   for (SCM s = me->get_property ("right-items");
 131        gh_pair_p (s);  s = gh_cdr (s))
 132     {
 133       Grob * g = unsmob_grob (gh_car (s));
 134
 135       max_corr = max_corr >?  next_note_correction (me, g,  bar_size);
 136       for (SCM t = g->get_property ("elements");
 137            gh_pair_p (t); t  = gh_cdr (t))
 138         max_corr = max_corr >? next_note_correction (me, unsmob_grob (gh_car (t)), bar_size);
 139
 140     }
 141
 142   return max_corr;
 143 }
 144
 145 void
 146 Staff_spacing::get_spacing_params (Grob *me, Real * space, Real * fixed)
 147 {
 148   *space = 1.0;
 149   *fixed = 1.0;
 150
 151   Grob * separation_item=0;
 152   Item * me_item  = dynamic_cast<Item*> (me);
 153
 154   for (SCM s = me->get_property ("left-items");
 155        gh_pair_p (s); s = gh_cdr (s))
 156     {
 157       Grob * cand = unsmob_grob (gh_car (s));
 158       if (cand && Separation_item::has_interface (cand))
 159         separation_item = cand ;
 160     }
 161
 162   //  printf ("doing col %d\n" , Paper_column::get_rank (left_col));
 163
 164   if (!separation_item)
 165     {
 166       programming_error ("no sep item");
 167       return;
 168     }
 169
 170   Interval last_ext;
 171   Grob *last_grob = Separation_item::extremal_break_aligned_grob (separation_item, RIGHT,
 172                                                  &last_ext);
 173   if (!last_grob)
 174     {
 175       /*
 176         TODO:
 177
 178         Should  insert a adjustable space here? For excercises, you might want to
 179         use a staff without a clef in the beginning.
 180        */
 181
 182       /*
 183         we used to have a warning here, but itgenerates a lot of
 184         spurious error messages.
 185       */
 186       return ;
 187     }
 188
 189   *fixed = last_ext[RIGHT];
 190   *space = *fixed + 1.0;
 191
 192   SCM alist = last_grob->get_property ("space-alist");
 193   if (!scm_list_p (alist))
 194     return ;
 195
 196   SCM space_def = scm_sloppy_assq (ly_symbol2scm ("first-note"), alist);
 197   if (me_item->break_status_dir () == CENTER)
 198     {
 199       SCM nndef = scm_sloppy_assq (ly_symbol2scm ("next-note"), alist);
 200       if (gh_pair_p (nndef))
 201         space_def = nndef;
 202     }
 203
 204
 205   if (!gh_pair_p (space_def))
 206     {
 207       programming_error ("Unknown prefatory spacing. ");
 208       return;
 209     }
 210
 211   space_def = gh_cdr (space_def);
 212   Real distance = gh_scm2double (gh_cdr (space_def));
 213   SCM type = gh_car (space_def) ;
 214
 215   *fixed = last_ext[RIGHT];
 216   if (type == ly_symbol2scm ("fixed-space"))
 217     {
 218      *fixed += distance;
 219      *space = *fixed;
 220     }
 221   else if (type == ly_symbol2scm ("extra-space"))
 222     {
 223       *space = *fixed + distance;
 224     }
 225   else if (type == ly_symbol2scm ("semi-fixed-space"))
 226     {
 227       *fixed += distance / 2;
 228       *space =  *fixed + distance/2;
 229     }
 230   else if (type == ly_symbol2scm ("minimum-space"))
 231     {
 232       *space = last_ext[LEFT] + (last_ext.length () >? distance);
 233     }
 234   else if (type == ly_symbol2scm ("minimum-fixed-space"))
 235     {
 236       *space = last_ext[LEFT] + (last_ext.length () >? distance);
 237       *fixed = *space;
 238     }
 239
 240   *space += next_notes_correction (me, last_grob);
 241 }
 242
 243
 244 ADD_INTERFACE (Staff_spacing,"staff-spacing-interface",
 245                "This object calculates spacing details from a "
 246                " breakable symbol (left) to another object. For example, it takes care "
 247                " of  optical spacing from  a bar lines to a note.",
 248   "stem-spacing-correction left-items right-items");