2 This file is part of LilyPond, the GNU music typesetter.
4 Copyright (C) 2006--2014 Han-Wen Nienhuys <hanwen@lilypond.org>
5 2007--2008 Rune Zedeler
6 2008 Joe Neeman <joeneeman@gmail.com>
8 LilyPond is free software: you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation, either version 3 of the License, or
11 (at your option) any later version.
13 LilyPond is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with LilyPond. If not, see <http://www.gnu.org/licenses/>.
26 todo: put string <-> pitch here too.
28 LY_DEFINE (ly_make_scale, "ly:make-scale",
31 " The argument is a vector of rational numbers, each of which"
32 " represents the number of 200 cent tones of a pitch above the"
35 bool type_ok = scm_is_vector (steps);
37 vector<Rational> tones;
40 int len = scm_c_vector_length (steps);
41 for (int i = 0; i < len; i++)
43 SCM step = scm_c_vector_ref (steps, i);
44 type_ok = type_ok && scm_is_rational (step);
47 Rational from_c (scm_to_int (scm_numerator (step)),
48 scm_to_int (scm_denominator (step)));
49 tones.push_back (from_c);
54 SCM_ASSERT_TYPE (type_ok, steps, SCM_ARG1, __FUNCTION__, "vector of rational");
56 Scale *s = new Scale (tones);
58 SCM retval = s->self_scm ();
64 LY_DEFINE (ly_default_scale, "ly:default-scale",
66 "Get the global default scale.")
68 return default_global_scale
69 ? default_global_scale->self_scm ()
73 Scale *default_global_scale = 0;
75 LY_DEFINE (ly_set_default_scale, "ly:set-default-scale",
77 "Set the global default scale. This determines the tuning of"
78 " pitches with no accidentals or key signatures. The first"
79 " pitch is C. Alterations are calculated relative to this"
80 " scale. The number of pitches in this scale determines the"
81 " number of scale steps that make up an octave. Usually the"
82 " 7-note major scale.")
84 LY_ASSERT_SMOB (Scale, scale, 1);
86 Scale *s = Scale::unsmob (scale);
87 if (default_global_scale)
88 default_global_scale->unprotect ();
89 default_global_scale = s;
92 return SCM_UNSPECIFIED;
96 Scale::step_count () const
98 return step_tones_.size ();
102 Scale::tones_at_step (int step, int octave) const
104 int normalized_step = normalize_step (step);
106 octave += (step - normalized_step) / step_count ();
108 // There are 6 tones in an octave.
109 return step_tones_[normalized_step] + Rational (octave * 6);
113 Scale::step_size (int step) const
115 int normalized_step = normalize_step (step);
117 // Wrap around if we are asked for the final note of the
118 // scale (6 is the number of tones of the octave above the
120 if (normalized_step + 1 == step_count ())
121 return Rational (6) - step_tones_[normalized_step];
123 return step_tones_[normalized_step + 1] - step_tones_[normalized_step];
127 Scale::normalize_step (int step) const
129 int ret = step % step_count ();
131 ret += step_count ();
138 Scale::Scale (vector<Rational> const &tones)
145 Scale::Scale (Scale const &src)
147 step_tones_ = src.step_tones_;