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"
28 todo: put string <-> pitch here too.
30 LY_DEFINE (ly_make_scale, "ly:make-scale",
33 " The argument is a vector of rational numbers, each of which"
34 " represents the number of 200 cent tones of a pitch above the"
37 bool type_ok = scm_is_vector (steps);
39 vector<Rational> tones;
42 int len = scm_c_vector_length (steps);
43 for (int i = 0; i < len; i++)
45 SCM step = scm_c_vector_ref (steps, i);
46 type_ok = type_ok && scm_is_rational (step);
49 Rational from_c (scm_to_int (scm_numerator (step)),
50 scm_to_int (scm_denominator (step)));
51 tones.push_back (from_c);
56 SCM_ASSERT_TYPE (type_ok, steps, SCM_ARG1, __FUNCTION__, "vector of rational");
58 return (new Scale (tones))->unprotect ();
61 Scale *default_global_scale = 0;
62 Protected_scm default_global_scale_scm (SCM_BOOL_F);
64 // TODO: This is somewhat fishy: pitches protect their scale via a
65 // mark_smob hook. But since pitches are of Simple_smob variety, they
66 // are unknown to GUILE unless a smobbed_copy has been created. So
67 // changing the default scale might cause some existing pitches to
68 // lose their scale's protection.
70 LY_DEFINE (ly_default_scale, "ly:default-scale",
72 "Get the global default scale.")
74 return default_global_scale_scm;
77 LY_DEFINE (ly_set_default_scale, "ly:set-default-scale",
79 "Set the global default scale. This determines the tuning of"
80 " pitches with no accidentals or key signatures. The first"
81 " pitch is C. Alterations are calculated relative to this"
82 " scale. The number of pitches in this scale determines the"
83 " number of scale steps that make up an octave. Usually the"
84 " 7-note major scale.")
86 LY_ASSERT_SMOB (Scale, scale, 1);
88 default_global_scale_scm = scale;
89 default_global_scale = unsmob<Scale> (scale);
91 return SCM_UNSPECIFIED;
95 Scale::step_count () const
97 return step_tones_.size ();
101 Scale::tones_at_step (int step, int octave) const
103 int normalized_step = normalize_step (step);
105 octave += (step - normalized_step) / step_count ();
107 // There are 6 tones in an octave.
108 return step_tones_[normalized_step] + Rational (octave * 6);
112 Scale::step_size (int step) const
114 int normalized_step = normalize_step (step);
116 // Wrap around if we are asked for the final note of the
117 // scale (6 is the number of tones of the octave above the
119 if (normalized_step + 1 == step_count ())
120 return Rational (6) - step_tones_[normalized_step];
122 return step_tones_[normalized_step + 1] - step_tones_[normalized_step];
126 Scale::normalize_step (int step) const
128 int ret = step % step_count ();
130 ret += step_count ();
137 Scale::Scale (vector<Rational> const &tones)
144 Scale::Scale (Scale const &src)
147 step_tones_ = src.step_tones_;