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_octave ();
  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_count ();
  57 }
  58
  59 Rational
  60 Pitch::tone_pitch () const
  61 {
  62   return scale_->tones_at_step (notename_, octave_) + alteration_;
  63 }
  64
  65 /* Calculate pitch height in 12th octave steps.  Don't assume
  66    normalized pitch as this function is used to normalize the pitch.  */
  67 int
  68 Pitch::rounded_semitone_pitch () const
  69 {
  70   return int (double (tone_pitch () * Rational (2)));
  71 }
  72
  73 int
  74 Pitch::rounded_quartertone_pitch () const
  75 {
  76   return int (double (tone_pitch () * Rational (4)));
  77 }
  78
  79 void
  80 Pitch::normalize_octave ()
  81 {
  82   int normalized_step = notename_ % scale_->step_count ();
  83   if (normalized_step < 0)
  84     normalized_step += scale_->step_count ();
  85
  86   octave_ += (notename_ - normalized_step) / scale_->step_count ();
  87   notename_ = normalized_step;
  88 }
  89
  90 void
  91 Pitch::normalize_alteration ()
  92 {
  93   while (alteration_ > Rational (1))
  94     {
  95       alteration_ -= scale_->step_size (notename_);
  96       notename_++;
  97     }
  98   while (alteration_ < Rational (-1))
  99     {
 100       notename_--;
 101       alteration_ += scale_->step_size (notename_);
 102     }
 103 }
 104
 105 void
 106 Pitch::normalize ()
 107 {
 108   normalize_alteration ();
 109   normalize_octave ();
 110 }
 111
 112 void
 113 Pitch::transpose (Pitch delta)
 114 {
 115   Rational new_alter = tone_pitch () + delta.tone_pitch ();
 116
 117   octave_ += delta.octave_;
 118   notename_ += delta.notename_;
 119   alteration_ += new_alter - tone_pitch ();
 120
 121   normalize_octave ();
 122 }
 123
 124 Pitch
 125 pitch_interval (Pitch const &from, Pitch const &to)
 126 {
 127   Rational sound = to.tone_pitch () - from.tone_pitch ();
 128   Pitch pt (to.get_octave () - from.get_octave (),
 129             to.get_notename () - from.get_notename (),
 130
 131             to.get_alteration () - from.get_alteration ());
 132
 133   return pt.transposed (Pitch (0, 0, sound - pt.tone_pitch ()));
 134 }
 135
 136 /* FIXME
 137    Merge with *pitch->text* funcs in chord-name.scm  */
 138 char const *accname[] = {"eses", "eseh", "es", "eh", "",
 139                          "ih", "is", "isih", "isis"};
 140
 141 string
 142 Pitch::to_string () const
 143 {
 144   int n = (notename_ + 2) % scale_->step_count ();
 145   string s = ::to_string (char (n + 'a'));
 146   Rational qtones = alteration_ * Rational (4,1);
 147   int qt = int (rint (Real (qtones)));
 148
 149   s += string (accname[qt + 4]);
 150   if (octave_ >= 0)
 151     {
 152       int o = octave_ + 1;
 153       while (o--)
 154         s += "'";
 155     }
 156   else if (octave_ < 0)
 157     {
 158       int o = (-octave_) - 1;
 159       while (o--)
 160         s += ::to_string (',');
 161     }
 162
 163   return s;
 164 }
 165
 166 /* Change me to relative, counting from last pitch p
 167    return copy of resulting pitch.  */
 168 Pitch
 169 Pitch::to_relative_octave (Pitch p) const
 170 {
 171   /* account for c' = octave 1 iso. 0 4 */
 172   int oct_mod = octave_ + 1;
 173   Pitch up_pitch (p);
 174   Pitch down_pitch (p);
 175
 176   up_pitch.alteration_ = alteration_;
 177   down_pitch.alteration_ = alteration_;
 178
 179   Pitch n = *this;
 180   up_pitch.up_to (notename_);
 181   down_pitch.down_to (notename_);
 182
 183   int h = p.steps ();
 184   if (abs (up_pitch.steps () - h) < abs (down_pitch.steps () - h))
 185     n = up_pitch;
 186   else
 187     n = down_pitch;
 188
 189   n.octave_ += oct_mod;
 190   return n;
 191 }
 192
 193 void
 194 Pitch::up_to (int notename)
 195 {
 196   if (notename_ > notename)
 197     octave_++;
 198   notename_ = notename;
 199 }
 200
 201 void
 202 Pitch::down_to (int notename)
 203 {
 204   if (notename_ < notename)
 205     octave_--;
 206   notename_ = notename;
 207 }
 208
 209 IMPLEMENT_TYPE_P (Pitch, "ly:pitch?");
 210 SCM
 211 Pitch::mark_smob (SCM x)
 212 {
 213   Pitch *p = (Pitch*) SCM_CELL_WORD_1 (x);
 214   return p->scale_->self_scm ();
 215 }
 216
 217 IMPLEMENT_SIMPLE_SMOBS (Pitch);
 218 int
 219 Pitch::print_smob (SCM s, SCM port, scm_print_state *)
 220 {
 221   Pitch *r = (Pitch *) SCM_CELL_WORD_1 (s);
 222   scm_puts ("#<Pitch ", port);
 223   scm_display (ly_string2scm (r->to_string ()), port);
 224   scm_puts (" >", port);
 225   return 1;
 226 }
 227
 228 SCM
 229 Pitch::equal_p (SCM a, SCM b)
 230 {
 231   Pitch *p = (Pitch *) SCM_CELL_WORD_1 (a);
 232   Pitch *q = (Pitch *) SCM_CELL_WORD_1 (b);
 233
 234   bool eq = p->notename_ == q->notename_
 235     && p->octave_ == q->octave_
 236     && p->alteration_ == q->alteration_;
 237
 238   return eq ? SCM_BOOL_T : SCM_BOOL_F;
 239 }
 240
 241 MAKE_SCHEME_CALLBACK (Pitch, less_p, 2);
 242 SCM
 243 Pitch::less_p (SCM p1, SCM p2)
 244 {
 245   Pitch *a = unsmob_pitch (p1);
 246   Pitch *b = unsmob_pitch (p2);
 247
 248   if (compare (*a, *b) < 0)
 249     return SCM_BOOL_T;
 250   else
 251     return SCM_BOOL_F;
 252 }
 253
 254 int
 255 Pitch::get_octave () const
 256 {
 257   return octave_;
 258 }
 259
 260 int
 261 Pitch::get_notename () const
 262 {
 263   return notename_;
 264 }
 265
 266 Rational
 267 Pitch::get_alteration () const
 268 {
 269   return alteration_;
 270 }
 271
 272 Pitch
 273 Pitch::transposed (Pitch d) const
 274 {
 275   Pitch p = *this;
 276   p.transpose (d);
 277   return p;
 278 }
 279
 280 Rational NATURAL_ALTERATION (0);
 281 Rational FLAT_ALTERATION (-1, 2);
 282 Rational DOUBLE_FLAT_ALTERATION (-1);
 283 Rational SHARP_ALTERATION (1, 2);
 284
 285 Pitch
 286 Pitch::negated () const
 287 {
 288   return pitch_interval (*this, Pitch ());
 289 }