2 This file is part of LilyPond, the GNU music typesetter.
4 Copyright (C) 2006--2015 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/>.
23 #include "protected-scm.hh"
27 todo: put string <-> pitch here too.
29 LY_DEFINE (ly_make_scale, "ly:make-scale",
32 " The argument is a vector of rational numbers, each of which"
33 " represents the number of 200 cent tones of a pitch above the"
36 bool type_ok = scm_is_vector (steps);
38 vector<Rational> tones;
41 int len = scm_c_vector_length (steps);
42 for (int i = 0; i < len; i++)
44 SCM step = scm_c_vector_ref (steps, i);
45 type_ok = type_ok && scm_is_rational (step);
48 Rational from_c (scm_to_int (scm_numerator (step)),
49 scm_to_int (scm_denominator (step)));
50 tones.push_back (from_c);
55 SCM_ASSERT_TYPE (type_ok, steps, SCM_ARG1, __FUNCTION__, "vector of rational");
57 return (new Scale (tones))->unprotect ();
60 Scale *default_global_scale = 0;
61 Protected_scm default_global_scale_scm (SCM_BOOL_F);
63 // TODO: This is somewhat fishy: pitches protect their scale via a
64 // mark_smob hook. But since pitches are of Simple_smob variety, they
65 // are unknown to GUILE unless a smobbed_copy has been created. So
66 // changing the default scale might cause some existing pitches to
67 // lose their scale's protection.
69 LY_DEFINE (ly_default_scale, "ly:default-scale",
71 "Get the global default scale.")
73 return default_global_scale_scm;
76 LY_DEFINE (ly_set_default_scale, "ly:set-default-scale",
78 "Set the global default scale. This determines the tuning of"
79 " pitches with no accidentals or key signatures. The first"
80 " pitch is C. Alterations are calculated relative to this"
81 " scale. The number of pitches in this scale determines the"
82 " number of scale steps that make up an octave. Usually the"
83 " 7-note major scale.")
85 LY_ASSERT_SMOB (Scale, scale, 1);
87 default_global_scale_scm = scale;
88 default_global_scale = unsmob<Scale> (scale);
90 return SCM_UNSPECIFIED;
94 Scale::step_count () const
96 return step_tones_.size ();
100 Scale::tones_at_step (int step, int octave) const
102 int normalized_step = normalize_step (step);
104 octave += (step - normalized_step) / step_count ();
106 // There are 6 tones in an octave.
107 return step_tones_[normalized_step] + Rational (octave * 6);
111 Scale::step_size (int step) const
113 int normalized_step = normalize_step (step);
115 // Wrap around if we are asked for the final note of the
116 // scale (6 is the number of tones of the octave above the
118 if (normalized_step + 1 == step_count ())
119 return Rational (6) - step_tones_[normalized_step];
121 return step_tones_[normalized_step + 1] - step_tones_[normalized_step];
125 Scale::normalize_step (int step) const
127 int ret = step % step_count ();
129 ret += step_count ();
136 Scale::Scale (vector<Rational> const &tones)
143 Scale::Scale (Scale const &src)
146 step_tones_ = src.step_tones_;