lily/pitch.cc

   1 /*
   2   musical-pitch.cc --  implement Pitch
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1998--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8
   9 #include "pitch.hh"
  10 #include "warn.hh"
  11 #include "main.hh"
  12 #include "ly-smobs.icc"
  13
  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 Pitch::Pitch ()
  24 {
  25   notename_ = 0;
  26   alteration_ = 0;
  27   octave_ = 0;
  28 }
  29
  30 int
  31 Pitch::compare (Pitch const &m1, Pitch const &m2)
  32 {
  33   int o=  m1.octave_ - m2.octave_;
  34   int n = m1.notename_ - m2.notename_;
  35   int a = m1.alteration_ - m2.alteration_;
  36
  37   if (o)
  38     return o;
  39   if (n)
  40     return n;
  41   if (a)
  42     return a;
  43   return 0;
  44 }
  45
  46 int
  47 Pitch::steps () const
  48 {
  49   return  notename_ + octave_*7;
  50 }
  51
  52 /* Should be settable from input?  */
  53 static Byte diatonic_scale_semitones[  ] = { 0, 2, 4, 5, 7, 9, 11 };
  54
  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 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
 163 /* FIXME
 164    Merge with *pitch->text* funcs in chord-name.scm  */
 165 char const *accname[] = {"eses", "eseh", "es", "eh", "",
 166                          "ih", "is" , "isih",  "isis"};
 167
 168 String
 169 Pitch::to_string () const
 170 {
 171   int n = (notename_ + 2) % 7;
 172   String s = ::to_string (char (n + 'a'));
 173   if (alteration_)
 174     s += String (accname[alteration_ - DOUBLE_FLAT]);
 175
 176   if (octave_ >= 0)
 177     {
 178       int o = octave_ + 1;
 179       while (o--)
 180         s += "'";
 181     }
 182   else if (octave_ < 0)
 183     {
 184       int o = (-octave_) - 1;
 185       while (o--)
 186         s += ::to_string (',');
 187     }
 188
 189   return s;
 190 }
 191
 192 /* Change me to relative, counting from last pitch p
 193    return copy of resulting pitch.  */
 194 Pitch
 195 Pitch::to_relative_octave (Pitch p) const
 196 {
 197   /* account for c' = octave 1 iso. 0 4 */
 198   int oct_mod = octave_  + 1;
 199   Pitch up_pitch (p);
 200   Pitch down_pitch (p);
 201
 202   up_pitch.alteration_ = alteration_;
 203   down_pitch.alteration_ = alteration_;
 204
 205   Pitch n = *this;
 206   up_pitch.up_to (notename_);
 207   down_pitch.down_to (notename_);
 208
 209   int h = p.steps ();
 210   if (abs (up_pitch.steps () - h) < abs (down_pitch.steps () - h))
 211     n = up_pitch;
 212   else
 213     n = down_pitch;
 214
 215   n.octave_ += oct_mod;
 216   return n;
 217 }
 218
 219 void
 220 Pitch::up_to (int notename)
 221 {
 222   if (notename_ > notename)
 223     octave_++;
 224   notename_  = notename;
 225 }
 226
 227 void
 228 Pitch::down_to (int notename)
 229 {
 230   if (notename_ < notename)
 231     octave_--;
 232   notename_ = notename;
 233 }
 234
 235 LY_DEFINE (ly_pitch_transpose, "ly:pitch-transpose",
 236            2, 0, 0, (SCM p, SCM delta),
 237            "Transpose @var{p} by the amount @var{delta}, "
 238            "where @var{delta} is relative to middle C.")
 239 {
 240   Pitch* t = unsmob_pitch (p);
 241   Pitch *d = unsmob_pitch (delta);
 242   SCM_ASSERT_TYPE (t, p, SCM_ARG1, __FUNCTION__, "pitch");
 243   SCM_ASSERT_TYPE (d, delta, SCM_ARG1, __FUNCTION__, "pitch");
 244   return t->transposed (*d).smobbed_copy ();
 245 }
 246
 247 IMPLEMENT_TYPE_P (Pitch, "ly:pitch?");
 248
 249 SCM
 250 Pitch::mark_smob (SCM)
 251 {
 252   return SCM_EOL;
 253 }
 254
 255 IMPLEMENT_SIMPLE_SMOBS (Pitch);
 256 int
 257 Pitch::print_smob (SCM s, SCM port, scm_print_state *)
 258 {
 259   Pitch *r = (Pitch *) ly_cdr (s);
 260   scm_puts ("#<Pitch ", port);
 261   scm_display (scm_makfrom0str (r->to_string ().to_str0 ()), port);
 262   scm_puts (" >", port);
 263   return 1;
 264 }
 265
 266 SCM
 267 Pitch::equal_p (SCM a , SCM b)
 268 {
 269   Pitch *p = (Pitch *) ly_cdr (a);
 270   Pitch *q = (Pitch *) ly_cdr (b);
 271
 272   bool eq = p->notename_ == q->notename_
 273     && p->octave_ == q->octave_
 274     && p->alteration_ == q->alteration_;
 275
 276   return eq ? SCM_BOOL_T : SCM_BOOL_F;
 277 }
 278
 279 MAKE_SCHEME_CALLBACK (Pitch, less_p, 2);
 280 SCM
 281 Pitch::less_p (SCM p1, SCM p2)
 282 {
 283   Pitch *a = unsmob_pitch (p1);
 284   Pitch *b = unsmob_pitch (p2);
 285
 286   if (compare (*a, *b) < 0)
 287     return SCM_BOOL_T;
 288   else
 289     return SCM_BOOL_F;
 290 }
 291
 292 /* Should add optional args.  */
 293 LY_DEFINE (make_pitch, "ly:make-pitch",
 294            3, 0, 0, (SCM octave, SCM note, SCM alter),
 295            "@var{octave} is specified by an integer, "
 296            "zero for the octave containing middle C.  "
 297            "@var{note} is a number from 0 to 6, "
 298            "with 0 corresponding to C and 6 corresponding to B.  "
 299            "The @var{alter} is zero for a natural, negative for "
 300            "flats, or positive for sharps. ")
 301 {
 302   SCM_ASSERT_TYPE (scm_integer_p (octave)== SCM_BOOL_T , octave, SCM_ARG1, __FUNCTION__, "integer");
 303   SCM_ASSERT_TYPE (scm_integer_p (note)== SCM_BOOL_T, note, SCM_ARG2, __FUNCTION__, "integer");
 304   SCM_ASSERT_TYPE (scm_integer_p (alter)== SCM_BOOL_T, alter, SCM_ARG3, __FUNCTION__, "integer");
 305
 306   Pitch p (gh_scm2int (octave), gh_scm2int (note), gh_scm2int (alter));
 307   return p.smobbed_copy ();
 308 }
 309
 310 LY_DEFINE (pitch_steps, "ly:pitch-steps", 1, 0, 0,
 311            (SCM p),
 312            "Number of steps counted from middle C of the pitch @var{p}.")
 313 {
 314   Pitch *pp = unsmob_pitch (p);
 315   SCM_ASSERT_TYPE (pp, p, SCM_ARG1, __FUNCTION__, "Pitch");
 316   return gh_int2scm (pp->steps ());
 317 }
 318
 319 LY_DEFINE (pitch_octave, "ly:pitch-octave",
 320            1, 0, 0, (SCM pp),
 321            "Extract the octave from pitch @var{p}.")
 322 {
 323   Pitch *p = unsmob_pitch (pp);
 324   SCM_ASSERT_TYPE (p, pp, SCM_ARG1, __FUNCTION__, "Pitch");
 325   int q = p->get_octave ();
 326   return gh_int2scm (q);
 327 }
 328
 329 LY_DEFINE (pitch_alteration, "ly:pitch-alteration",
 330            1, 0, 0, (SCM pp),
 331            "Extract the alteration from pitch  @var{p}.")
 332 {
 333   Pitch *p = unsmob_pitch (pp);
 334   SCM_ASSERT_TYPE (p, pp, SCM_ARG1, __FUNCTION__, "Pitch");
 335   int q = p->get_alteration ();
 336
 337   return gh_int2scm (q);
 338 }
 339
 340 LY_DEFINE (pitch_notename, "ly:pitch-notename",
 341            1, 0, 0, (SCM pp),
 342            "Extract the note name from pitch  @var{pp}.")
 343 {
 344   Pitch *p = unsmob_pitch (pp);
 345   SCM_ASSERT_TYPE (p, pp, SCM_ARG1, __FUNCTION__, "Pitch");
 346   int q = p->get_notename ();
 347   return gh_int2scm (q);
 348 }
 349
 350 LY_DEFINE (ly_pitch_quartertones,  "ly:pitch-quartertones",
 351            1, 0, 0, (SCM pp),
 352            "Calculate the number of quarter tones of @var{p} from middle C.")
 353 {
 354   Pitch *p = unsmob_pitch (pp);
 355   SCM_ASSERT_TYPE (p, pp, SCM_ARG1, __FUNCTION__, "Pitch");
 356   int q = p->quartertone_pitch ();
 357   return gh_int2scm (q);
 358 }
 359
 360 LY_DEFINE (ly_pitch_semitones,  "ly:pitch-semitones",
 361            1, 0, 0, (SCM pp),
 362            "calculate the number of semitones of @var{p} from middle C.")
 363 {
 364   Pitch *p = unsmob_pitch (pp);
 365   SCM_ASSERT_TYPE (p, pp, SCM_ARG1, __FUNCTION__, "Pitch");
 366   int q = p->semitone_pitch ();
 367   return gh_int2scm (q);
 368 }
 369
 370 LY_DEFINE (pitch_less, "ly:pitch<?",
 371            2, 0, 0, (SCM p1, SCM p2),
 372            "Is @var{p1} lexicographically smaller than @var{p2}?")
 373 {
 374   Pitch *a = unsmob_pitch (p1);
 375   Pitch *b = unsmob_pitch (p2);
 376
 377   SCM_ASSERT_TYPE (a, p1, SCM_ARG1, __FUNCTION__, "Pitch");
 378   SCM_ASSERT_TYPE (b, p2, SCM_ARG2, __FUNCTION__, "Pitch");
 379
 380   if (Pitch::compare (*a, *b) < 0)
 381     return SCM_BOOL_T;
 382   else
 383     return SCM_BOOL_F;
 384 }
 385
 386 LY_DEFINE (ly_pitch_diff, "ly:pitch-diff",
 387            2 ,0, 0, (SCM pitch, SCM  root),
 388            "Return pitch @var{delta} such that @code{pitch} transposed by "
 389            "@var{delta} equals @var{root}" )
 390 {
 391   Pitch *p = unsmob_pitch (pitch);
 392   Pitch *r = unsmob_pitch (root);
 393   SCM_ASSERT_TYPE (p, pitch, SCM_ARG1, __FUNCTION__, "Pitch");
 394   SCM_ASSERT_TYPE (r, root, SCM_ARG2, __FUNCTION__, "Pitch");
 395
 396   return interval (*r, *p).smobbed_copy ();
 397 }
 398
 399
 400 int
 401 Pitch::get_octave ()const
 402 {
 403   return octave_;
 404 }
 405
 406 int
 407 Pitch::get_notename () const
 408 {
 409   return notename_;
 410 }
 411
 412 int
 413 Pitch::get_alteration () const
 414 {
 415   return alteration_;
 416 }
 417
 418 Pitch
 419 Pitch::transposed (Pitch d) const
 420 {
 421   Pitch p = *this;
 422   p.transpose (d);
 423   return p;
 424 }