lilypond-2.23.5/lily/pitch.cc

/*
  This file is part of LilyPond, the GNU music typesetter.

  Copyright (C) 1998--2021 Han-Wen Nienhuys <hanwen@xs4all.nl>

  LilyPond is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  LilyPond is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "pitch.hh"

#include "scale.hh"
#include "string-convert.hh"
#include "warn.hh"

#include <cmath>

using std::string;

Pitch::Pitch (int o, int n, Rational a)
{
  notename_ = n;
  alteration_ = a;
  octave_ = o;
  scale_ = default_global_scale;
  normalize_octave ();
}

/* FIXME: why is octave == 0 and default not middleC ? */
Pitch::Pitch ()
{
  notename_ = 0;
  scale_ = default_global_scale;
  octave_ = 0;
  alteration_ = 0;
}

int
Pitch::compare (Pitch const &m1, Pitch const &m2)
{
  int o = m1.octave_ - m2.octave_;
  int n = m1.notename_ - m2.notename_;
  Rational a = m1.alteration_ - m2.alteration_;

  if (o)
    return o;
  if (n)
    return n;
  if (a)
    return (a > 0) ? 1 : -1;

  return 0;
}

int
Pitch::steps () const
{
  return notename_ + octave_ * scale_->step_count ();
}

Rational
Pitch::tone_pitch () const
{
  return scale_->tones_at_step (notename_, octave_) + alteration_;
}

/* Calculate pitch height in 12th octave steps.  Don't assume
   normalized pitch as this function is used to normalize the pitch.  */
int
Pitch::rounded_semitone_pitch () const
{
  return int (floor (double (tone_pitch () * Rational (2) + Rational (1, 2))));
}

int
Pitch::rounded_quartertone_pitch () const
{
  return int (floor (double (tone_pitch () * Rational (4) + Rational (1, 2))));
}

void
Pitch::normalize_octave ()
{
  int normalized_step = notename_ % scale_->step_count ();
  if (normalized_step < 0)
    normalized_step += scale_->step_count ();

  octave_ += (notename_ - normalized_step) / scale_->step_count ();
  notename_ = normalized_step;
}

void
Pitch::normalize_alteration ()
{
  while (alteration_ > Rational (1))
    {
      alteration_ -= scale_->step_size (notename_);
      notename_++;
    }
  while (alteration_ < Rational (-1))
    {
      notename_--;
      alteration_ += scale_->step_size (notename_);
    }
}

void
Pitch::normalize ()
{
  normalize_alteration ();
  normalize_octave ();
}

void
Pitch::transpose (Pitch delta)
{
  Rational new_alter = tone_pitch () + delta.tone_pitch ();

  octave_ += delta.octave_;
  notename_ += delta.notename_;
  alteration_ += new_alter - tone_pitch ();

  normalize_octave ();
}

Pitch
pitch_interval (Pitch const &from, Pitch const &to)
{
  Rational sound = to.tone_pitch () - from.tone_pitch ();
  Pitch pt (to.get_octave () - from.get_octave (),
            to.get_notename () - from.get_notename (),

            to.get_alteration () - from.get_alteration ());

  return pt.transposed (Pitch (0, 0, sound - pt.tone_pitch ()));
}

/* FIXME
   Merge with *note-name->string* in chord-name.scm  */
char const *accname[] = {"eses", "eseh", "es", "eh", "",
                         "ih", "is", "isih", "isis"
                        };

string
Pitch::to_string () const
{
  int n = (notename_ + 2) % scale_->step_count ();
  string s (1, static_cast<char> (n + 'a'));
  Rational qtones = alteration_ * Rational (4, 1);
  size_t qt = size_t (rint (static_cast<Real> (qtones) + 4.0));
  if (qt < sizeof (accname) / sizeof (accname[0]))
    {
      s += string (accname[qt]);
    }
  else
    {
      s += "??";
    }

  if (octave_ >= 0)
    {
      int o = octave_ + 1;
      while (o--)
        s += "'";
    }
  else if (octave_ < 0)
    {
      int o = (-octave_) - 1;
      while (o--)
        s += ',';
    }

  return s;
}

/* Change me to relative, counting from last pitch p
   return copy of resulting pitch.  */
Pitch
Pitch::to_relative_octave (Pitch p) const
{
  /* account for c' = octave 1 iso. 0 4 */
  int oct_mod = octave_ + 1;
  Pitch up_pitch (p);
  Pitch down_pitch (p);

  up_pitch.alteration_ = alteration_;
  down_pitch.alteration_ = alteration_;

  Pitch n = *this;
  up_pitch.up_to (notename_);
  down_pitch.down_to (notename_);

  int h = p.steps ();
  if (abs (up_pitch.steps () - h) < abs (down_pitch.steps () - h))
    n = up_pitch;
  else
    n = down_pitch;

  n.octave_ += oct_mod;
  return n;
}

void
Pitch::up_to (int notename)
{
  if (notename_ > notename)
    octave_++;
  notename_ = notename;
}

void
Pitch::down_to (int notename)
{
  if (notename_ < notename)
    octave_--;
  notename_ = notename;
}

const char *const Pitch::type_p_name_ = "ly:pitch?";

SCM
Pitch::mark_smob () const
{
  return scale_->self_scm ();
}

int
Pitch::print_smob (SCM port, scm_print_state *) const
{
  scm_puts ("#<Pitch ", port);
  scm_display (ly_string2scm (to_string ()), port);
  scm_puts (" >", port);
  return 1;
}

SCM
Pitch::equal_p (SCM a, SCM b)
{
  Pitch *p = unsmob<Pitch> (a);
  Pitch *q = unsmob<Pitch> (b);

  bool eq = p->notename_ == q->notename_
            && p->octave_ == q->octave_
            && p->alteration_ == q->alteration_;

  return eq ? SCM_BOOL_T : SCM_BOOL_F;
}

MAKE_SCHEME_CALLBACK (Pitch, less_p, 2);
SCM
Pitch::less_p (SCM p1, SCM p2)
{
  Pitch *a = unsmob<Pitch> (p1);
  Pitch *b = unsmob<Pitch> (p2);

  if (compare (*a, *b) < 0)
    return SCM_BOOL_T;
  else
    return SCM_BOOL_F;
}

int
Pitch::get_octave () const
{
  return octave_;
}

int
Pitch::get_notename () const
{
  return notename_;
}

Rational
Pitch::get_alteration () const
{
  return alteration_;
}

Pitch
Pitch::transposed (Pitch d) const
{
  Pitch p = *this;
  p.transpose (d);
  return p;
}

Pitch
Pitch::normalized () const
{
  Pitch p = *this;
  p.normalize ();
  return p;
}

Rational NATURAL_ALTERATION (0);
Rational FLAT_ALTERATION (-1, 2);
Rational DOUBLE_FLAT_ALTERATION (-1);
Rational SHARP_ALTERATION (1, 2);

Pitch
Pitch::negated () const
{
  return pitch_interval (*this, Pitch ());
}

/* TODO: find a good place for this function */
void
set_middle_C (Context *c)
{
  int clef_pos = from_scm (get_property (c, "middleCClefPosition"), 0);
  int offset = from_scm (get_property (c, "middleCOffset"), 0);
  /* middleCCuePosition overrides the clef! */
  SCM cue_pos = get_property (c, "middleCCuePosition");
  if (scm_is_number (cue_pos))
    clef_pos = from_scm (cue_pos, 0);

  set_property (c, ly_symbol2scm ("middleCPosition"), to_scm (clef_pos + offset));
}