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--2005 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8   keyplacement by Mats Bengtsson
   9 */
  10
  11 #include "item.hh"
  12 #include "output-def.hh"
  13 #include "font-interface.hh"
  14 #include "staff-symbol-referencer.hh"
  15 #include "lookup.hh"
  16 #include "accidental-interface.hh"
  17
  18 struct Key_signature_interface
  19 {
  20   DECLARE_SCHEME_CALLBACK (print, (SCM));
  21
  22   static bool has_interface (Grob *);
  23 };
  24
  25 /*
  26   FIXME: too much hardcoding here.
  27 */
  28 const int FLAT_TOP_PITCH = 2; /* fes, ges, as and bes typeset in lower octave */
  29 const int SHARP_TOP_PITCH = 4; /*  ais and bis typeset in lower octave */
  30
  31 /*
  32   TODO: look this up. I'm not sure where the naturals ought to go.
  33 */
  34 const int NATURAL_TOP_PITCH = 4;
  35
  36 /*
  37   FIXME: key-item should just get a list of (position, acc), and leave
  38   the thinking to other parties.
  39
  40   - TODO: put this in Scheme
  41
  42   TODO: can  we do without c0pos? it's partly musical.
  43 */
  44 int
  45 alteration_pos (SCM what, int alter, int c0p)
  46 {
  47   if (scm_is_pair (what))
  48     return scm_to_int (scm_car (what)) * 7 + scm_to_int (scm_cdr (what)) + c0p;
  49
  50   int p = scm_to_int (what);
  51
  52   // Find the c in the range -4 through 2
  53   int from_bottom_pos = c0p + 4;
  54   from_bottom_pos = from_bottom_pos % 7;
  55   from_bottom_pos = (from_bottom_pos + 7) % 7; // Precaution to get positive.
  56   int c0 = from_bottom_pos - 4;
  57
  58   if ((alter < 0 && ((p > FLAT_TOP_PITCH) || (p + c0 > 4)) && (p + c0 > 1))
  59       || (alter > 0 && ((p > SHARP_TOP_PITCH) || (p + c0 > 5)) && (p + c0 > 2))
  60       || (alter == 0 && ((p > NATURAL_TOP_PITCH) || (p + c0 > 5)) && (p + c0 > 2)))
  61     {
  62       p -= 7; /* Typeset below c_position */
  63     }
  64
  65   /* Provide for the four cases in which there's a glitch
  66      it's a hack, but probably not worth
  67      the effort of finding a nicer solution.
  68      --dl. */
  69   if (c0 == 2 && alter > 0 && p == 3)
  70     p -= 7;
  71   if (c0==-3 && alter > 0 && p ==-1)
  72     p += 7;
  73   if (c0==-4 && alter < 0 && p ==-1)
  74     p += 7;
  75   if (c0==-2 && alter < 0 && p ==-3)
  76     p += 7;
  77
  78   return p + c0;
  79 }
  80
  81 /*
  82   TODO
  83   - space the `natural' signs wider
  84 */
  85 MAKE_SCHEME_CALLBACK (Key_signature_interface, print, 1);
  86 SCM
  87 Key_signature_interface::print (SCM smob)
  88 {
  89   Item *me = dynamic_cast<Item *> (unsmob_grob (smob));
  90
  91   Real inter = Staff_symbol_referencer::staff_space (me) / 2.0;
  92
  93   SCM scm_style = me->get_property ("style");
  94   String style;
  95   if (scm_is_symbol (scm_style))
  96     {
  97       style = ly_symbol2string (scm_style);
  98     }
  99   else
 100     {
 101       style = "";
 102     }
 103
 104   SCM newas = me->get_property ("alteration-alist");
 105   Stencil mol;
 106
 107   SCM c0s = me->get_property ("c0-position");
 108   int c0p = 0;
 109   if (scm_is_number (c0s))
 110     c0p = scm_to_int (c0s);
 111
 112   /*
 113     SCM lists are stacks, so we work from right to left, ending with
 114     the cancellation signature.
 115   */
 116
 117   int last_pos = -1000;
 118   Font_metric *fm = Font_interface::get_default_font (me);
 119   for (SCM s = newas; scm_is_pair (s); s = scm_cdr (s))
 120     {
 121       int alteration = scm_to_int (scm_cdar (s));
 122       String font_char
 123         = Accidental_interface::get_fontcharname (style, alteration);
 124       Stencil acc (fm->find_by_name ("accidentals." + font_char));
 125
 126       if (acc.is_empty ())
 127         {
 128           me->warning (_f ("accidental `%s' not found", font_char));
 129         }
 130       else
 131         {
 132           SCM what = scm_caar (s);
 133           int pos = alteration_pos (what, alteration, c0p);
 134           acc.translate_axis (pos * inter, Y_AXIS);
 135
 136           /*
 137             The natural sign (unlike flat & sharp)
 138             has vertical edges on both sides. A little padding is
 139             needed to prevent collisions.
 140           */
 141           Real padding = 0.0;
 142           if (alteration == 0
 143               && last_pos < pos + 2
 144               && last_pos > pos - 6)
 145             padding = 0.3;
 146
 147           mol.add_at_edge (X_AXIS, LEFT, acc, padding, 0);
 148           last_pos = pos;
 149         }
 150     }
 151
 152   mol.align_to (X_AXIS, LEFT);
 153
 154   return mol.smobbed_copy ();
 155 }
 156
 157 ADD_INTERFACE (Key_signature_interface, "key-signature-interface",
 158                "A group of accidentals, to be printed as signature sign.",
 159                "style c0-position alteration-alist");