lily/key-signature-interface.cc

   1 /*
   2   key-item.cc -- implement Key_signature_interface
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1996--2002 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8   keyplacement by Mats Bengtsson
   9 */
  10
  11 #include "item.hh"
  12
  13 #include "molecule.hh"
  14 #include "paper-def.hh"
  15 #include "font-interface.hh"
  16 #include "staff-symbol-referencer.hh"
  17 #include "lookup.hh"
  18 #include "lily-guile.hh"
  19 #include "lily-proto.hh"
  20
  21
  22 struct Key_signature_interface
  23 {
  24   DECLARE_SCHEME_CALLBACK (brew_molecule, (SCM ));
  25
  26   static bool has_interface (Grob*);
  27 };
  28
  29
  30 /*
  31   FIXME: too much hardcoding here.
  32  */
  33 const int FLAT_TOP_PITCH=2; /* fes,ges,as and bes typeset in lower octave */
  34 const int SHARP_TOP_PITCH=4; /*  ais and bis typeset in lower octave */
  35
  36 /*
  37   TODO: look this up. I'm not sure where the naturals ought to go.
  38  */
  39 const int NATURAL_TOP_PITCH = 4;
  40
  41
  42
  43
  44 /*
  45   FIXME: key-item should just get a list of (position, acc), and leave
  46   the thinking to other parties.
  47
  48   - TODO: put this in Scheme
  49
  50   - lots of values trivially shared (key doesn't change very
  51   often). Compute those once, and use that as cache for the rest.
  52
  53 */
  54 int
  55 alteration_pos  (SCM what, int alter, int c0p)
  56 {
  57   if (gh_pair_p (what))
  58     return gh_scm2int (ly_car (what)) * 7 + gh_scm2int (ly_cdr (what)) + c0p;
  59
  60   int p = gh_scm2int (what);
  61
  62   // Find the c in the range -4 through 2
  63   int from_bottom_pos = c0p + 4;
  64   from_bottom_pos = from_bottom_pos%7;
  65   from_bottom_pos = (from_bottom_pos + 7)%7; // Precaution to get positive.
  66   int c0 = from_bottom_pos - 4;
  67
  68
  69   if ((alter <0 && ((p>FLAT_TOP_PITCH) || (p+c0>4)) && (p+c0>1))
  70       || (alter >0 && ((p > SHARP_TOP_PITCH) || (p+c0>5)) && (p+c0>2))
  71       || (alter == 0 && ((p > NATURAL_TOP_PITCH) || (p + c0>5)) && (p + c0>2)))
  72     {
  73       p -= 7; /* Typeset below c_position */
  74     }
  75   /* Provide for the four cases in which there's a glitch
  76        it's a hack, but probably not worth
  77        the effort of finding a nicer solution.
  78        --dl. */
  79   if (c0==2 && alter >0 && p==3)
  80     p -= 7;
  81   if (c0==-3 && alter>0 && p==-1)
  82     p += 7;
  83   if (c0==-4 && alter<0 && p==-1)
  84     p += 7;
  85   if (c0==-2 && alter<0 && p==-3)
  86     p += 7;
  87
  88   return p + c0;
  89 }
  90
  91 /*
  92   TODO
  93   - space the `natural' signs wider
  94  */
  95 MAKE_SCHEME_CALLBACK (Key_signature_interface,brew_molecule,1);
  96 SCM
  97 Key_signature_interface::brew_molecule (SCM smob)
  98 {
  99   Grob*me =unsmob_grob (smob);
 100
 101   Real inter = Staff_symbol_referencer::staff_space (me)/2.0;
 102
 103   SCM scm_style = me->get_grob_property ("style");
 104   String style;
 105   if (gh_symbol_p (scm_style))
 106     {
 107       style = ly_scm2string (scm_symbol_to_string (scm_style));
 108     }
 109   else
 110     {
 111       style = "";
 112     }
 113
 114   SCM newas = me->get_grob_property ("new-accidentals");
 115   Molecule mol;
 116
 117   SCM c0s = me->get_grob_property ("c0-position");
 118   int c0p=0;
 119   if (gh_number_p (c0s))
 120      c0p = gh_scm2int (c0s);
 121
 122   /*
 123     SCM lists are stacks, so we work from right to left, ending with
 124     the cancellation signature.
 125   */
 126
 127   for (SCM s = newas; gh_pair_p (s); s = ly_cdr (s))
 128     {
 129       SCM what = ly_caar (s);
 130       int alter = gh_scm2int (ly_cdar (s));
 131       int pos = alteration_pos (what, alter, c0p);
 132
 133       Molecule m = Font_interface::get_default_font (me)->
 134           find_by_name (String ("accidentals-") + style + to_string (alter));
 135       m.translate_axis (pos * inter, Y_AXIS);
 136       mol.add_at_edge (X_AXIS, LEFT, m, 0);
 137     }
 138
 139   Item *it = dynamic_cast<Item*> (me) ;
 140   if (it->break_status_dir () != RIGHT)
 141     {
 142       SCM old = me->get_grob_property ("old-accidentals");
 143
 144       /*
 145         Add half a space between  cancellation and key sig.
 146
 147         As suggested by [Ross], p.148.
 148        */
 149       Interval x (0, inter);
 150       Interval y (0,0);
 151
 152       mol.add_at_edge (X_AXIS, LEFT, Lookup::blank (Box (x,y)),0);
 153
 154       Molecule natural;
 155       if (gh_pair_p (old))
 156         natural=Font_interface::get_default_font (me)->
 157             find_by_name (String ("accidentals-") + style + String ("0"));
 158
 159       for (; gh_pair_p (old); old = ly_cdr (old))
 160         {
 161           SCM found = scm_assoc (ly_caar (old), newas);
 162           if (found == SCM_BOOL_F
 163               || ly_cdr (found) != ly_cdar (old))
 164             {
 165               SCM what = ly_caar (old);
 166               int alter = 0;
 167               int pos = alteration_pos (what, alter, c0p);
 168
 169               Molecule m = natural;
 170               m.translate_axis (pos* inter, Y_AXIS);
 171
 172               /*
 173                 The natural sign (unlike flat & sharp)
 174                 has vertical edges on both sides. A little padding is
 175                 needed to prevent collisions.
 176                */
 177               Real padding = 0.1 ;
 178               mol.add_at_edge (X_AXIS, LEFT, m, padding);
 179             }
 180         }
 181     }
 182
 183   mol.align_to (X_AXIS, LEFT);
 184
 185   return mol.smobbed_copy ();
 186 }
 187
 188 ADD_INTERFACE (Key_signature_interface, "key-signature-interface",
 189   "A group of accidentals, to be printed as signature sign.",
 190   "c0-position old-accidentals new-accidentals");