lily/pitch.cc

   1 /*
   2   musical-pitch.cc -- implement Pitch
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1998--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "pitch.hh"
  10
  11 #include "main.hh"
  12 #include "scale.hh"
  13 #include "string-convert.hh"
  14 #include "warn.hh"
  15
  16 #include "ly-smobs.icc"
  17
  18
  19 Pitch::Pitch (int o, int n, Rational a)
  20 {
  21   notename_ = n;
  22   alteration_ = a;
  23   octave_ = o;
  24   scale_ = default_global_scale;
  25   normalize ();
  26 }
  27
  28 /* FIXME: why is octave == 0 and default not middleC ? */
  29 Pitch::Pitch ()
  30 {
  31   notename_ = 0;
  32   scale_ = default_global_scale;
  33   octave_ = 0;
  34 }
  35
  36 int
  37 Pitch::compare (Pitch const &m1, Pitch const &m2)
  38 {
  39   int o = m1.octave_ - m2.octave_;
  40   int n = m1.notename_ - m2.notename_;
  41   Rational a = m1.alteration_ - m2.alteration_;
  42
  43   if (o)
  44     return o;
  45   if (n)
  46     return n;
  47   if (a)
  48     return a;
  49
  50   return 0;
  51 }
  52
  53 int
  54 Pitch::steps () const
  55 {
  56   return notename_ + octave_ * scale_->step_tones_.size ();
  57 }
  58
  59 Rational
  60 Pitch::tone_pitch () const
  61 {
  62   int o = octave_;
  63   int n = notename_;
  64   while (n < 0)
  65     {
  66       n += scale_->step_tones_.size ();
  67       o--;
  68     }
  69
  70   /*
  71     we're effictively hardcoding the octave to 6 whole-tones,
  72     which is as arbitrary as coding it to 1200 cents
  73   */
  74   Rational tones ((o + n / scale_->step_tones_.size ()) * 6, 1);
  75   tones += scale_->step_tones_[n % scale_->step_tones_.size ()];
  76
  77   tones += alteration_;
  78
  79   return tones;
  80 }
  81
  82 /* Calculate pitch height in 12th octave steps.  Don't assume
  83    normalized pitch as this function is used to normalize the pitch.  */
  84 int
  85 Pitch::rounded_semitone_pitch () const
  86 {
  87   return int (double (tone_pitch () * Rational (2)));
  88 }
  89
  90 int
  91 Pitch::rounded_quartertone_pitch () const
  92 {
  93   return int (double (tone_pitch () * Rational (4)));
  94 }
  95
  96 void
  97 Pitch::normalize ()
  98 {
  99   Rational pitch = tone_pitch ();
 100   while (notename_ >= (int) scale_->step_tones_.size ())
 101     {
 102       notename_ -= scale_->step_tones_.size ();
 103       octave_++;
 104       alteration_ -= tone_pitch () - pitch;
 105     }
 106   while (notename_ < 0)
 107     {
 108       notename_ += scale_->step_tones_.size ();
 109       octave_--;
 110       alteration_ -= tone_pitch () - pitch;
 111     }
 112
 113   while (alteration_ > Rational (1))
 114     {
 115       if (notename_ == int (scale_->step_tones_.size ()))
 116         {
 117           notename_ = 0;
 118           octave_++;
 119         }
 120       else
 121         notename_++;
 122
 123       alteration_ = Rational (0);
 124       alteration_ -= tone_pitch () - pitch;
 125     }
 126   while (alteration_ < Rational (-1))
 127     {
 128       if (notename_ == 0)
 129         {
 130           notename_ = scale_->step_tones_.size ();
 131           octave_--;
 132         }
 133       else
 134         notename_--;
 135
 136       alteration_ = 0;
 137       alteration_ -= tone_pitch () - pitch;
 138     }
 139 }
 140
 141 void
 142 Pitch::transpose (Pitch delta)
 143 {
 144   Rational new_alter = tone_pitch () + delta.tone_pitch ();
 145
 146   octave_ += delta.octave_;
 147   notename_ += delta.notename_;
 148   alteration_ += new_alter - tone_pitch ();
 149
 150   normalize ();
 151 }
 152
 153 Pitch
 154 pitch_interval (Pitch const &from, Pitch const &to)
 155 {
 156   Rational sound = to.tone_pitch () - from.tone_pitch ();
 157   Pitch pt (to.get_octave () - from.get_octave (),
 158             to.get_notename () - from.get_notename (),
 159
 160             to.get_alteration () - from.get_alteration ());
 161
 162   return pt.transposed (Pitch (0, 0, sound - pt.tone_pitch ()));
 163 }
 164
 165 /* FIXME
 166    Merge with *pitch->text* funcs in chord-name.scm  */
 167 char const *accname[] = {"eses", "eseh", "es", "eh", "",
 168                          "ih", "is", "isih", "isis"};
 169
 170 string
 171 Pitch::to_string () const
 172 {
 173   int n = (notename_ + 2) % scale_->step_tones_.size ();
 174   string s = ::to_string (char (n + 'a'));
 175   Rational qtones = alteration_ * Rational (4,1);
 176   int qt = int (rint (Real (qtones)));
 177
 178   s += string (accname[qt + 4]);
 179   if (octave_ >= 0)
 180     {
 181       int o = octave_ + 1;
 182       while (o--)
 183         s += "'";
 184     }
 185   else if (octave_ < 0)
 186     {
 187       int o = (-octave_) - 1;
 188       while (o--)
 189         s += ::to_string (',');
 190     }
 191
 192   return s;
 193 }
 194
 195 /* Change me to relative, counting from last pitch p
 196    return copy of resulting pitch.  */
 197 Pitch
 198 Pitch::to_relative_octave (Pitch p) const
 199 {
 200   /* account for c' = octave 1 iso. 0 4 */
 201   int oct_mod = octave_ + 1;
 202   Pitch up_pitch (p);
 203   Pitch down_pitch (p);
 204
 205   up_pitch.alteration_ = alteration_;
 206   down_pitch.alteration_ = alteration_;
 207
 208   Pitch n = *this;
 209   up_pitch.up_to (notename_);
 210   down_pitch.down_to (notename_);
 211
 212   int h = p.steps ();
 213   if (abs (up_pitch.steps () - h) < abs (down_pitch.steps () - h))
 214     n = up_pitch;
 215   else
 216     n = down_pitch;
 217
 218   n.octave_ += oct_mod;
 219   return n;
 220 }
 221
 222 void
 223 Pitch::up_to (int notename)
 224 {
 225   if (notename_ > notename)
 226     octave_++;
 227   notename_ = notename;
 228 }
 229
 230 void
 231 Pitch::down_to (int notename)
 232 {
 233   if (notename_ < notename)
 234     octave_--;
 235   notename_ = notename;
 236 }
 237
 238 IMPLEMENT_TYPE_P (Pitch, "ly:pitch?");
 239 SCM
 240 Pitch::mark_smob (SCM x)
 241 {
 242   Pitch *p = (Pitch*) SCM_CELL_WORD_1 (x);
 243   return p->scale_->self_scm ();
 244 }
 245
 246 IMPLEMENT_SIMPLE_SMOBS (Pitch);
 247 int
 248 Pitch::print_smob (SCM s, SCM port, scm_print_state *)
 249 {
 250   Pitch *r = (Pitch *) SCM_CELL_WORD_1 (s);
 251   scm_puts ("#<Pitch ", port);
 252   scm_display (ly_string2scm (r->to_string ()), port);
 253   scm_puts (" >", port);
 254   return 1;
 255 }
 256
 257 SCM
 258 Pitch::equal_p (SCM a, SCM b)
 259 {
 260   Pitch *p = (Pitch *) SCM_CELL_WORD_1 (a);
 261   Pitch *q = (Pitch *) SCM_CELL_WORD_1 (b);
 262
 263   bool eq = p->notename_ == q->notename_
 264     && p->octave_ == q->octave_
 265     && p->alteration_ == q->alteration_;
 266
 267   return eq ? SCM_BOOL_T : SCM_BOOL_F;
 268 }
 269
 270 MAKE_SCHEME_CALLBACK (Pitch, less_p, 2);
 271 SCM
 272 Pitch::less_p (SCM p1, SCM p2)
 273 {
 274   Pitch *a = unsmob_pitch (p1);
 275   Pitch *b = unsmob_pitch (p2);
 276
 277   if (compare (*a, *b) < 0)
 278     return SCM_BOOL_T;
 279   else
 280     return SCM_BOOL_F;
 281 }
 282
 283 int
 284 Pitch::get_octave () const
 285 {
 286   return octave_;
 287 }
 288
 289 int
 290 Pitch::get_notename () const
 291 {
 292   return notename_;
 293 }
 294
 295 Rational
 296 Pitch::get_alteration () const
 297 {
 298   return alteration_;
 299 }
 300
 301 Pitch
 302 Pitch::transposed (Pitch d) const
 303 {
 304   Pitch p = *this;
 305   p.transpose (d);
 306   return p;
 307 }
 308
 309 Rational NATURAL_ALTERATION (0);
 310 Rational FLAT_ALTERATION (-1, 2);
 311 Rational DOUBLE_FLAT_ALTERATION (-1);
 312 Rational SHARP_ALTERATION (1, 2);
 313
 314 Pitch
 315 Pitch::negated () const
 316 {
 317   return pitch_interval (*this, Pitch ());
 318 }