lily/pitch.cc

   1 /*
   2   musical-pitch.cc -- implement Pitch
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1998--2005 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8
   9 #include "pitch.hh"
  10 #include "warn.hh"
  11 #include "main.hh"
  12
  13 #include "ly-smobs.icc"
  14
  15 Pitch::Pitch (int o, int n, int a)
  16 {
  17   notename_ = n;
  18   alteration_ = a;
  19   octave_ = o;
  20   normalise ();
  21 }
  22
  23 /* FIXME: why is octave == 0 and default not middleC ? */
  24 Pitch::Pitch ()
  25 {
  26   notename_ = 0;
  27   alteration_ = 0;
  28   octave_ = 0;
  29 }
  30
  31 int
  32 Pitch::compare (Pitch const &m1, Pitch const &m2)
  33 {
  34   int o = m1.octave_ - m2.octave_;
  35   int n = m1.notename_ - m2.notename_;
  36   int a = m1.alteration_ - m2.alteration_;
  37
  38   if (o)
  39     return o;
  40   if (n)
  41     return n;
  42   if (a)
  43     return a;
  44   return 0;
  45 }
  46
  47 int
  48 Pitch::steps () const
  49 {
  50   return notename_ + octave_ * 7;
  51 }
  52
  53 /* Should be settable from input?  */
  54 static Byte diatonic_scale_semitones[ ] = { 0, 2, 4, 5, 7, 9, 11 };
  55
  56 /* Calculate pitch height in 12th octave steps.  Don't assume
  57    normalised pitch as this function is used to normalise the pitch.  */
  58 int
  59 Pitch::semitone_pitch () const
  60 {
  61   int o = octave_;
  62   int n = notename_;
  63   while (n < 0)
  64     {
  65       n += 7;
  66       o--;
  67     }
  68
  69   if (alteration_ % 2)
  70     programming_error ("semitone_pitch () called on quarter tone alteration.");
  71
  72   return ((o + n / 7) * 12
  73           + diatonic_scale_semitones[n % 7]
  74           + (alteration_ / 2));
  75 }
  76
  77 int
  78 Pitch::quartertone_pitch () const
  79 {
  80   int o = octave_;
  81   int n = notename_;
  82   while (n < 0)
  83     {
  84       n += 7;
  85       o--;
  86     }
  87
  88   return ((o + n / 7) * 24
  89           + 2 * diatonic_scale_semitones[n % 7]
  90           + alteration_);
  91 }
  92
  93 void
  94 Pitch::normalise ()
  95 {
  96   int pitch = quartertone_pitch ();
  97   while (notename_ >= 7)
  98     {
  99       notename_ -= 7;
 100       octave_++;
 101       alteration_ -= quartertone_pitch () - pitch;
 102     }
 103   while (notename_ < 0)
 104     {
 105       notename_ += 7;
 106       octave_--;
 107       alteration_ -= quartertone_pitch () - pitch;
 108     }
 109   while (alteration_ > DOUBLE_SHARP)
 110     {
 111       if (notename_ == 6)
 112         {
 113           notename_ = 0;
 114           octave_++;
 115         }
 116       else
 117         notename_++;
 118
 119       alteration_ = 0;
 120       alteration_ -= quartertone_pitch () - pitch;
 121     }
 122
 123   while (alteration_ < DOUBLE_FLAT)
 124     {
 125       if (notename_ == 0)
 126         {
 127           notename_ = 6;
 128           octave_--;
 129         }
 130       else
 131         notename_--;
 132
 133       alteration_ = 0;
 134       alteration_ -= quartertone_pitch () - pitch;
 135     }
 136 }
 137
 138 /* WHugh, wat een intervaas */
 139 void
 140 Pitch::transpose (Pitch delta)
 141 {
 142   int new_semi = quartertone_pitch () +delta.quartertone_pitch ();
 143   octave_ += delta.octave_;
 144   notename_ += delta.notename_;
 145   alteration_ += new_semi - quartertone_pitch ();
 146
 147   normalise ();
 148 }
 149
 150 Pitch
 151 pitch_interval (Pitch const &from, Pitch const &to)
 152 {
 153   int sound = to.quartertone_pitch () - from.quartertone_pitch ();
 154   Pitch pt (to.get_octave () - from.get_octave (),
 155             to.get_notename () - from.get_notename (),
 156
 157             to.get_alteration () - from.get_alteration ());
 158
 159   return pt.transposed (Pitch (0, 0, sound - pt.quartertone_pitch ()));
 160 }
 161
 162 /* FIXME
 163    Merge with *pitch->text* funcs in chord-name.scm  */
 164 char const *accname[] = {"eses", "eseh", "es", "eh", "",
 165                          "ih", "is", "isih", "isis"};
 166
 167 String
 168 Pitch::to_string () const
 169 {
 170   int n = (notename_ + 2) % 7;
 171   String s = ::to_string (char (n + 'a'));
 172   if (alteration_)
 173     s += String (accname[alteration_ - DOUBLE_FLAT]);
 174
 175   if (octave_ >= 0)
 176     {
 177       int o = octave_ + 1;
 178       while (o--)
 179         s += "'";
 180     }
 181   else if (octave_ < 0)
 182     {
 183       int o = (-octave_) - 1;
 184       while (o--)
 185         s += ::to_string (',');
 186     }
 187
 188   return s;
 189 }
 190
 191 /* Change me to relative, counting from last pitch p
 192    return copy of resulting pitch.  */
 193 Pitch
 194 Pitch::to_relative_octave (Pitch p) const
 195 {
 196   /* account for c' = octave 1 iso. 0 4 */
 197   int oct_mod = octave_ + 1;
 198   Pitch up_pitch (p);
 199   Pitch down_pitch (p);
 200
 201   up_pitch.alteration_ = alteration_;
 202   down_pitch.alteration_ = alteration_;
 203
 204   Pitch n = *this;
 205   up_pitch.up_to (notename_);
 206   down_pitch.down_to (notename_);
 207
 208   int h = p.steps ();
 209   if (abs (up_pitch.steps () - h) < abs (down_pitch.steps () - h))
 210     n = up_pitch;
 211   else
 212     n = down_pitch;
 213
 214   n.octave_ += oct_mod;
 215   return n;
 216 }
 217
 218 void
 219 Pitch::up_to (int notename)
 220 {
 221   if (notename_ > notename)
 222     octave_++;
 223   notename_ = notename;
 224 }
 225
 226 void
 227 Pitch::down_to (int notename)
 228 {
 229   if (notename_ < notename)
 230     octave_--;
 231   notename_ = notename;
 232 }
 233
 234 IMPLEMENT_TYPE_P (Pitch, "ly:pitch?");
 235
 236 SCM
 237 Pitch::mark_smob (SCM)
 238 {
 239   return SCM_EOL;
 240 }
 241
 242 IMPLEMENT_SIMPLE_SMOBS (Pitch);
 243 int
 244 Pitch::print_smob (SCM s, SCM port, scm_print_state *)
 245 {
 246   Pitch *r = (Pitch *) SCM_CELL_WORD_1 (s);
 247   scm_puts ("#<Pitch ", port);
 248   scm_display (scm_makfrom0str (r->to_string ().to_str0 ()), port);
 249   scm_puts (" >", port);
 250   return 1;
 251 }
 252
 253 SCM
 254 Pitch::equal_p (SCM a, SCM b)
 255 {
 256   Pitch *p = (Pitch *) SCM_CELL_WORD_1 (a);
 257   Pitch *q = (Pitch *) SCM_CELL_WORD_1 (b);
 258
 259   bool eq = p->notename_ == q->notename_
 260     && p->octave_ == q->octave_
 261     && p->alteration_ == q->alteration_;
 262
 263   return eq ? SCM_BOOL_T : SCM_BOOL_F;
 264 }
 265
 266 MAKE_SCHEME_CALLBACK (Pitch, less_p, 2);
 267 SCM
 268 Pitch::less_p (SCM p1, SCM p2)
 269 {
 270   Pitch *a = unsmob_pitch (p1);
 271   Pitch *b = unsmob_pitch (p2);
 272
 273   if (compare (*a, *b) < 0)
 274     return SCM_BOOL_T;
 275   else
 276     return SCM_BOOL_F;
 277 }
 278
 279 int
 280 Pitch::get_octave () const
 281 {
 282   return octave_;
 283 }
 284
 285 int
 286 Pitch::get_notename () const
 287 {
 288   return notename_;
 289 }
 290
 291 int
 292 Pitch::get_alteration () const
 293 {
 294   return alteration_;
 295 }
 296
 297 Pitch
 298 Pitch::transposed (Pitch d) const
 299 {
 300   Pitch p = *this;
 301   p.transpose (d);
 302   return p;
 303 }