X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fscale.cc;h=3dff7b4b3320c6a2a654663b5f26ed047ab38c1f;hb=9e781b7dc83b60a543ce218aa1a5f139f74c760f;hp=89e8103887b3af3c2d98ace94ecf4e8065137b7c;hpb=7a3c3526e082ada6fefbe564315046a14ecf609c;p=lilypond.git diff --git a/lily/scale.cc b/lily/scale.cc index 89e8103887..3dff7b4b33 100644 --- a/lily/scale.cc +++ b/lily/scale.cc @@ -1,10 +1,22 @@ -/* - scale.cc -- implement Scale - - source file of the GNU LilyPond music typesetter - - (c) 2006 Han-Wen Nienhuys - +/* + This file is part of LilyPond, the GNU music typesetter. + + Copyright (C) 2006--2014 Han-Wen Nienhuys + 2007--2008 Rune Zedeler + 2008 Joe Neeman + + 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 . */ #include "scale.hh" @@ -13,90 +25,134 @@ /* todo: put string <-> pitch here too. - */ LY_DEFINE (ly_make_scale, "ly:make-scale", - 1, 0, 0, (SCM steps), - "Create a scale. Takes a vector of ints as argument") + 1, 0, 0, (SCM steps), + "Create a scale." + " The argument is a vector of rational numbers, each of which" + " represents the number of 200 cent tones of a pitch above the" + " tonic.") { bool type_ok = scm_is_vector (steps); - vector semitones; + vector tones; if (type_ok) { int len = scm_c_vector_length (steps); - for (int i = 0 ; i < len; i++) - { - SCM step = scm_c_vector_ref (steps, i); - type_ok = type_ok && scm_is_rational (step); - if (type_ok) - { - Rational from_c (scm_to_int (scm_numerator (step)), - scm_to_int (scm_denominator (step))); - semitones.push_back (from_c); - } - } + for (int i = 0; i < len; i++) + { + SCM step = scm_c_vector_ref (steps, i); + type_ok = type_ok && scm_is_rational (step); + if (type_ok) + { + Rational from_c (scm_to_int (scm_numerator (step)), + scm_to_int (scm_denominator (step))); + tones.push_back (from_c); + } + } } - - SCM_ASSERT_TYPE (type_ok, steps, SCM_ARG1, __FUNCTION__, "vector of int"); - Scale *s = new Scale; - s->step_tones_ = semitones; + SCM_ASSERT_TYPE (type_ok, steps, SCM_ARG1, __FUNCTION__, "vector of rational"); - SCM retval = s->self_scm (); + Scale *s = new Scale (tones); + SCM retval = s->self_scm (); s->unprotect (); - + return retval; } LY_DEFINE (ly_default_scale, "ly:default-scale", - 0, 0, 0, (), - "Get the global default scale.") + 0, 0, 0, (), + "Get the global default scale.") { return default_global_scale - ? SCM_BOOL_F - : default_global_scale->self_scm (); + ? default_global_scale->self_scm () + : SCM_BOOL_F; } - -Scale * default_global_scale = 0; +Scale *default_global_scale = 0; LY_DEFINE (ly_set_default_scale, "ly:set-default-scale", - 1, 0, 0, (SCM scale), - "Set the global default scale.") + 1, 0, 0, (SCM scale), + "Set the global default scale. This determines the tuning of" + " pitches with no accidentals or key signatures. The first" + " pitch is C. Alterations are calculated relative to this" + " scale. The number of pitches in this scale determines the" + " number of scale steps that make up an octave. Usually the" + " 7-note major scale.") { - Scale *s = Scale::unsmob (scale); - SCM_ASSERT_TYPE (s, scale, SCM_ARG1, __FUNCTION__, "scale"); + LY_ASSERT_SMOB (Scale, scale, 1); + Scale *s = Scale::unsmob (scale); if (default_global_scale) default_global_scale->unprotect (); default_global_scale = s; s->protect (); - + return SCM_UNSPECIFIED; } +int +Scale::step_count () const +{ + return step_tones_.size (); +} + +Rational +Scale::tones_at_step (int step, int octave) const +{ + int normalized_step = normalize_step (step); + + octave += (step - normalized_step) / step_count (); + + // There are 6 tones in an octave. + return step_tones_[normalized_step] + Rational (octave * 6); +} + +Rational +Scale::step_size (int step) const +{ + int normalized_step = normalize_step (step); + + // Wrap around if we are asked for the final note of the + // scale (6 is the number of tones of the octave above the + // first note). + if (normalized_step + 1 == step_count ()) + return Rational (6) - step_tones_[normalized_step]; + + return step_tones_[normalized_step + 1] - step_tones_[normalized_step]; +} + +int +Scale::normalize_step (int step) const +{ + int ret = step % step_count (); + if (ret < 0) + ret += step_count (); + + return ret; +} int -Scale::print_smob (SCM x, SCM port, scm_print_state *) +Scale::print_smob (SCM /* x */, + SCM port, + scm_print_state *) { - (void) x; - - scm_puts ("#", port); + scm_puts ("#", port); return 1; } - SCM -Scale::mark_smob (SCM x) +Scale::mark_smob (SCM) { - (void) x; return SCM_UNSPECIFIED; } -Scale::Scale () +Scale::Scale (vector const &tones) { + step_tones_ = tones; + smobify_self (); } @@ -106,10 +162,9 @@ Scale::Scale (Scale const &src) smobify_self (); } - Scale::~Scale () { } -IMPLEMENT_SMOBS(Scale); -IMPLEMENT_DEFAULT_EQUAL_P(Scale); +IMPLEMENT_SMOBS (Scale); +IMPLEMENT_DEFAULT_EQUAL_P (Scale);