lily/pitch.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 1998--2011 Han-Wen Nienhuys <hanwen@xs4all.nl>
   5
   6   LilyPond is free software: you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published by
   8   the Free Software Foundation, either version 3 of the License, or
   9   (at your option) any later version.
  10
  11   LilyPond is distributed in the hope that it will be useful,
  12   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14   GNU General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "pitch.hh"
  21
  22 #include "main.hh"
  23 #include "scale.hh"
  24 #include "string-convert.hh"
  25 #include "warn.hh"
  26
  27 #include "ly-smobs.icc"
  28
  29
  30 Pitch::Pitch (int o, int n, Rational a)
  31 {
  32   notename_ = n;
  33   alteration_ = a;
  34   octave_ = o;
  35   scale_ = default_global_scale;
  36   normalize_octave ();
  37 }
  38
  39 /* FIXME: why is octave == 0 and default not middleC ? */
  40 Pitch::Pitch ()
  41 {
  42   notename_ = 0;
  43   scale_ = default_global_scale;
  44   octave_ = 0;
  45 }
  46
  47 int
  48 Pitch::compare (Pitch const &m1, Pitch const &m2)
  49 {
  50   int o = m1.octave_ - m2.octave_;
  51   int n = m1.notename_ - m2.notename_;
  52   Rational a = m1.alteration_ - m2.alteration_;
  53
  54   if (o)
  55     return o;
  56   if (n)
  57     return n;
  58   if (a)
  59     return a > (Rational)0;
  60
  61   return 0;
  62 }
  63
  64 int
  65 Pitch::steps () const
  66 {
  67   return notename_ + octave_ * scale_->step_count ();
  68 }
  69
  70 Rational
  71 Pitch::tone_pitch () const
  72 {
  73   return scale_->tones_at_step (notename_, octave_) + alteration_;
  74 }
  75
  76 /* Calculate pitch height in 12th octave steps.  Don't assume
  77    normalized pitch as this function is used to normalize the pitch.  */
  78 int
  79 Pitch::rounded_semitone_pitch () const
  80 {
  81   return int (double (tone_pitch () * Rational (2)));
  82 }
  83
  84 int
  85 Pitch::rounded_quartertone_pitch () const
  86 {
  87   return int (double (tone_pitch () * Rational (4)));
  88 }
  89
  90 void
  91 Pitch::normalize_octave ()
  92 {
  93   int normalized_step = notename_ % scale_->step_count ();
  94   if (normalized_step < 0)
  95     normalized_step += scale_->step_count ();
  96
  97   octave_ += (notename_ - normalized_step) / scale_->step_count ();
  98   notename_ = normalized_step;
  99 }
 100
 101 void
 102 Pitch::normalize_alteration ()
 103 {
 104   while (alteration_ > Rational (1))
 105     {
 106       alteration_ -= scale_->step_size (notename_);
 107       notename_++;
 108     }
 109   while (alteration_ < Rational (-1))
 110     {
 111       notename_--;
 112       alteration_ += scale_->step_size (notename_);
 113     }
 114 }
 115
 116 void
 117 Pitch::normalize ()
 118 {
 119   normalize_alteration ();
 120   normalize_octave ();
 121 }
 122
 123 void
 124 Pitch::transpose (Pitch delta)
 125 {
 126   Rational new_alter = tone_pitch () + delta.tone_pitch ();
 127
 128   octave_ += delta.octave_;
 129   notename_ += delta.notename_;
 130   alteration_ += new_alter - tone_pitch ();
 131
 132   normalize_octave ();
 133 }
 134
 135 Pitch
 136 pitch_interval (Pitch const &from, Pitch const &to)
 137 {
 138   Rational sound = to.tone_pitch () - from.tone_pitch ();
 139   Pitch pt (to.get_octave () - from.get_octave (),
 140             to.get_notename () - from.get_notename (),
 141
 142             to.get_alteration () - from.get_alteration ());
 143
 144   return pt.transposed (Pitch (0, 0, sound - pt.tone_pitch ()));
 145 }
 146
 147 /* FIXME
 148    Merge with *pitch->text* funcs in chord-name.scm  */
 149 char const *accname[] = {"eses", "eseh", "es", "eh", "",
 150                          "ih", "is", "isih", "isis"};
 151
 152 string
 153 Pitch::to_string () const
 154 {
 155   int n = (notename_ + 2) % scale_->step_count ();
 156   string s = ::to_string (char (n + 'a'));
 157   Rational qtones = alteration_ * Rational (4,1);
 158   int qt = int (rint (Real (qtones)));
 159
 160   s += string (accname[qt + 4]);
 161   if (octave_ >= 0)
 162     {
 163       int o = octave_ + 1;
 164       while (o--)
 165         s += "'";
 166     }
 167   else if (octave_ < 0)
 168     {
 169       int o = (-octave_) - 1;
 170       while (o--)
 171         s += ::to_string (',');
 172     }
 173
 174   return s;
 175 }
 176
 177 /* Change me to relative, counting from last pitch p
 178    return copy of resulting pitch.  */
 179 Pitch
 180 Pitch::to_relative_octave (Pitch p) const
 181 {
 182   /* account for c' = octave 1 iso. 0 4 */
 183   int oct_mod = octave_ + 1;
 184   Pitch up_pitch (p);
 185   Pitch down_pitch (p);
 186
 187   up_pitch.alteration_ = alteration_;
 188   down_pitch.alteration_ = alteration_;
 189
 190   Pitch n = *this;
 191   up_pitch.up_to (notename_);
 192   down_pitch.down_to (notename_);
 193
 194   int h = p.steps ();
 195   if (abs (up_pitch.steps () - h) < abs (down_pitch.steps () - h))
 196     n = up_pitch;
 197   else
 198     n = down_pitch;
 199
 200   n.octave_ += oct_mod;
 201   return n;
 202 }
 203
 204 void
 205 Pitch::up_to (int notename)
 206 {
 207   if (notename_ > notename)
 208     octave_++;
 209   notename_ = notename;
 210 }
 211
 212 void
 213 Pitch::down_to (int notename)
 214 {
 215   if (notename_ < notename)
 216     octave_--;
 217   notename_ = notename;
 218 }
 219
 220 IMPLEMENT_TYPE_P (Pitch, "ly:pitch?");
 221 SCM
 222 Pitch::mark_smob (SCM x)
 223 {
 224   Pitch *p = (Pitch*) SCM_CELL_WORD_1 (x);
 225   return p->scale_->self_scm ();
 226 }
 227
 228 IMPLEMENT_SIMPLE_SMOBS (Pitch);
 229 int
 230 Pitch::print_smob (SCM s, SCM port, scm_print_state *)
 231 {
 232   Pitch *r = (Pitch *) SCM_CELL_WORD_1 (s);
 233   scm_puts ("#<Pitch ", port);
 234   scm_display (ly_string2scm (r->to_string ()), port);
 235   scm_puts (" >", port);
 236   return 1;
 237 }
 238
 239 SCM
 240 Pitch::equal_p (SCM a, SCM b)
 241 {
 242   Pitch *p = (Pitch *) SCM_CELL_WORD_1 (a);
 243   Pitch *q = (Pitch *) SCM_CELL_WORD_1 (b);
 244
 245   bool eq = p->notename_ == q->notename_
 246     && p->octave_ == q->octave_
 247     && p->alteration_ == q->alteration_;
 248
 249   return eq ? SCM_BOOL_T : SCM_BOOL_F;
 250 }
 251
 252 MAKE_SCHEME_CALLBACK (Pitch, less_p, 2);
 253 SCM
 254 Pitch::less_p (SCM p1, SCM p2)
 255 {
 256   Pitch *a = unsmob_pitch (p1);
 257   Pitch *b = unsmob_pitch (p2);
 258
 259   if (compare (*a, *b) < 0)
 260     return SCM_BOOL_T;
 261   else
 262     return SCM_BOOL_F;
 263 }
 264
 265 int
 266 Pitch::get_octave () const
 267 {
 268   return octave_;
 269 }
 270
 271 int
 272 Pitch::get_notename () const
 273 {
 274   return notename_;
 275 }
 276
 277 Rational
 278 Pitch::get_alteration () const
 279 {
 280   return alteration_;
 281 }
 282
 283 Pitch
 284 Pitch::transposed (Pitch d) const
 285 {
 286   Pitch p = *this;
 287   p.transpose (d);
 288   return p;
 289 }
 290
 291 Pitch
 292 Pitch::normalized () const
 293 {
 294   Pitch p = *this;
 295   p.normalize ();
 296   return p;
 297 }
 298
 299 Rational NATURAL_ALTERATION (0);
 300 Rational FLAT_ALTERATION (-1, 2);
 301 Rational DOUBLE_FLAT_ALTERATION (-1);
 302 Rational SHARP_ALTERATION (1, 2);
 303
 304 Pitch
 305 Pitch::negated () const
 306 {
 307   return pitch_interval (*this, Pitch ());
 308 }