lily/pitch-scheme.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 2005--2010 Han-Wen Nienhuys <hanwen@xs4all.nl>
   5
   6   LilyPond is free software: you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published by
   8   the Free Software Foundation, either version 3 of the License, or
   9   (at your option) any later version.
  10
  11   LilyPond is distributed in the hope that it will be useful,
  12   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14   GNU General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "pitch.hh"
  21
  22 LY_DEFINE (ly_pitch_transpose, "ly:pitch-transpose",
  23            2, 0, 0, (SCM p, SCM delta),
  24            "Transpose @var{p} by the amount @var{delta},"
  25            " where @var{delta} is relative to middle@tie{}C.")
  26 {
  27   LY_ASSERT_SMOB (Pitch, p, 1);
  28   LY_ASSERT_SMOB (Pitch, delta, 2);
  29
  30   Pitch *t = unsmob_pitch (p);
  31   Pitch *d = unsmob_pitch (delta);
  32   return t->transposed (*d).smobbed_copy ();
  33 }
  34
  35 /* Should add optional args.  */
  36 LY_DEFINE (ly_make_pitch, "ly:make-pitch",
  37            2, 1, 0, (SCM octave, SCM note, SCM alter),
  38            "@var{octave} is specified by an integer, zero for the octave"
  39            " containing middle@tie{}C. @var{note} is a number indexing the"
  40            " global default scale, with 0 corresponding to pitch@tie{}C"
  41            " and 6 usually corresponding to pitch@tie{}B. @var{alter} is"
  42            " a rational number of 200-cent whole tones for alteration.")
  43
  44 {
  45   LY_ASSERT_TYPE (scm_is_integer, octave, 1);
  46   LY_ASSERT_TYPE (scm_is_integer, note, 2);
  47   LY_ASSERT_TYPE (scm_is_rational, alter, 3);
  48
  49   Pitch p (scm_to_int (octave), scm_to_int (note),
  50            ly_scm2rational (alter));
  51
  52   return p.smobbed_copy ();
  53 }
  54
  55 LY_DEFINE (ly_pitch_negate, "ly:pitch-negate", 1, 0, 0,
  56            (SCM p),
  57            "Negate @var{p}.")
  58 {
  59   LY_ASSERT_SMOB (Pitch, p, 1);
  60   Pitch *pp = unsmob_pitch (p);
  61   return pp->negated ().smobbed_copy ();
  62 }
  63
  64 LY_DEFINE (ly_pitch_steps, "ly:pitch-steps", 1, 0, 0,
  65            (SCM p),
  66            "Number of steps counted from middle@tie{}C of the"
  67            " pitch@tie{}@var{p}.")
  68 {
  69   LY_ASSERT_SMOB (Pitch, p, 1);
  70   Pitch *pp = unsmob_pitch (p);
  71   return scm_from_int (pp->steps ());
  72 }
  73
  74 LY_DEFINE (ly_pitch_octave, "ly:pitch-octave",
  75            1, 0, 0, (SCM pp),
  76            "Extract the octave from pitch@tie{}@var{pp}.")
  77 {
  78   LY_ASSERT_SMOB (Pitch, pp, 1);
  79   Pitch *p = unsmob_pitch (pp);
  80   int q = p->get_octave ();
  81   return scm_from_int (q);
  82 }
  83
  84 LY_DEFINE (ly_pitch_alteration, "ly:pitch-alteration",
  85            1, 0, 0, (SCM pp),
  86            "Extract the alteration from pitch@tie{}@var{pp}.")
  87 {
  88   LY_ASSERT_SMOB (Pitch, pp, 1);
  89   Pitch *p = unsmob_pitch (pp);
  90   Rational q = p->get_alteration ();
  91
  92   return ly_rational2scm (q);
  93 }
  94
  95 LY_DEFINE (pitch_notename, "ly:pitch-notename",
  96            1, 0, 0, (SCM pp),
  97            "Extract the note name from pitch @var{pp}.")
  98 {
  99   LY_ASSERT_SMOB (Pitch, pp, 1);
 100   Pitch *p = unsmob_pitch (pp);
 101   int q = p->get_notename ();
 102   return scm_from_int (q);
 103 }
 104
 105 LY_DEFINE (ly_pitch_quartertones, "ly:pitch-quartertones",
 106            1, 0, 0, (SCM pp),
 107            "Calculate the number of quarter tones of@tie{}@var{pp} from"
 108            " middle@tie{}C.")
 109 {
 110   LY_ASSERT_SMOB (Pitch, pp, 1);
 111   Pitch *p = unsmob_pitch (pp);
 112   int q = p->rounded_quartertone_pitch ();
 113   return scm_from_int (q);
 114 }
 115
 116 LY_DEFINE (ly_pitch_semitones, "ly:pitch-semitones",
 117            1, 0, 0, (SCM pp),
 118            "Calculate the number of semitones of@tie{}@var{pp} from"
 119            " middle@tie{}C.")
 120 {
 121   LY_ASSERT_SMOB (Pitch, pp, 1);
 122   Pitch *p = unsmob_pitch (pp);
 123   int q = p->rounded_semitone_pitch ();
 124   return scm_from_int (q);
 125 }
 126
 127 LY_DEFINE (ly_pitch_less_p, "ly:pitch<?",
 128            2, 0, 0, (SCM p1, SCM p2),
 129            "Is @var{p1} lexicographically smaller than @var{p2}?")
 130 {
 131   LY_ASSERT_SMOB (Pitch, p1, 1);
 132   LY_ASSERT_SMOB (Pitch, p2, 2);
 133
 134   Pitch *a = unsmob_pitch (p1);
 135   Pitch *b = unsmob_pitch (p2);
 136
 137   if (Pitch::compare (*a, *b) < 0)
 138     return SCM_BOOL_T;
 139   else
 140     return SCM_BOOL_F;
 141 }
 142
 143 LY_DEFINE (ly_pitch_diff, "ly:pitch-diff",
 144            2, 0, 0, (SCM pitch, SCM root),
 145            "Return pitch @var{delta} such that @var{pitch} transposed by"
 146            " @var{delta} equals @var{root}.")
 147 {
 148
 149   LY_ASSERT_SMOB (Pitch, pitch, 1);
 150   LY_ASSERT_SMOB (Pitch, root, 2);
 151
 152   Pitch *p = unsmob_pitch (pitch);
 153   Pitch *r = unsmob_pitch (root);
 154
 155   return pitch_interval (*r, *p).smobbed_copy ();
 156 }
 157
 158 /* FIXME: probably isn't the right place for this function */
 159 #include "context.hh"
 160 LY_DEFINE (ly_set_middle_C_x, "ly:set-middle-C!",
 161            1, 0, 0, (SCM context),
 162            "Set the @code{middleCPosition} variable in @var{context}"
 163            " based on the variables @code{middleCClefPosition} and"
 164            " middleCOffset.")
 165 {
 166   LY_ASSERT_SMOB (Context, context, 1);
 167
 168   Context *c = unsmob_context (context);
 169   int clef_pos = robust_scm2int (c->get_property ("middleCClefPosition"), 0);
 170   int offset = robust_scm2int (c->get_property ("middleCOffset"), 0);
 171
 172   c->set_property (ly_symbol2scm ("middleCPosition"), scm_from_int (clef_pos + offset));
 173   return SCM_UNDEFINED;
 174 }