lily/pitch-scheme.cc

   1 /*
   2   pitch-scheme.cc -- implement scheme functions for Pitch
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2005--2009 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "pitch.hh"
  10
  11 LY_DEFINE (ly_pitch_transpose, "ly:pitch-transpose",
  12            2, 0, 0, (SCM p, SCM delta),
  13            "Transpose @var{p} by the amount @var{delta},"
  14            " where @var{delta} is relative to middle@tie{}C.")
  15 {
  16   LY_ASSERT_SMOB (Pitch, p, 1);
  17   LY_ASSERT_SMOB (Pitch, delta, 2);
  18
  19   Pitch *t = unsmob_pitch (p);
  20   Pitch *d = unsmob_pitch (delta);
  21   return t->transposed (*d).smobbed_copy ();
  22 }
  23
  24 /* Should add optional args.  */
  25 LY_DEFINE (ly_make_pitch, "ly:make-pitch",
  26            2, 1, 0, (SCM octave, SCM note, SCM alter),
  27            "@var{octave} is specified by an integer, zero for the octave"
  28            " containing middle@tie{}C. @var{note} is a number indexing the"
  29            " global default scale, with 0 corresponding to pitch@tie{}C"
  30            " and 6 usually corresponding to pitch@tie{}B. @var{alter} is"
  31            " a rational number of 200-cent whole tones for alteration.")
  32
  33 {
  34   LY_ASSERT_TYPE (scm_is_integer, octave, 1);
  35   LY_ASSERT_TYPE (scm_is_integer, note, 2);
  36   LY_ASSERT_TYPE (scm_is_rational, alter, 3);
  37
  38   Pitch p (scm_to_int (octave), scm_to_int (note),
  39            ly_scm2rational (alter));
  40
  41   return p.smobbed_copy ();
  42 }
  43
  44 LY_DEFINE (ly_pitch_negate, "ly:pitch-negate", 1, 0, 0,
  45            (SCM p),
  46            "Negate @var{p}.")
  47 {
  48   LY_ASSERT_SMOB (Pitch, p, 1);
  49   Pitch *pp = unsmob_pitch (p);
  50   return pp->negated ().smobbed_copy ();
  51 }
  52
  53 LY_DEFINE (ly_pitch_steps, "ly:pitch-steps", 1, 0, 0,
  54            (SCM p),
  55            "Number of steps counted from middle@tie{}C of the"
  56            " pitch@tie{}@var{p}.")
  57 {
  58   LY_ASSERT_SMOB (Pitch, p, 1);
  59   Pitch *pp = unsmob_pitch (p);
  60   return scm_from_int (pp->steps ());
  61 }
  62
  63 LY_DEFINE (ly_pitch_octave, "ly:pitch-octave",
  64            1, 0, 0, (SCM pp),
  65            "Extract the octave from pitch@tie{}@var{pp}.")
  66 {
  67   LY_ASSERT_SMOB (Pitch, pp, 1);
  68   Pitch *p = unsmob_pitch (pp);
  69   int q = p->get_octave ();
  70   return scm_from_int (q);
  71 }
  72
  73 LY_DEFINE (ly_pitch_alteration, "ly:pitch-alteration",
  74            1, 0, 0, (SCM pp),
  75            "Extract the alteration from pitch@tie{}@var{pp}.")
  76 {
  77   LY_ASSERT_SMOB (Pitch, pp, 1);
  78   Pitch *p = unsmob_pitch (pp);
  79   Rational q = p->get_alteration ();
  80
  81   return ly_rational2scm (q);
  82 }
  83
  84 LY_DEFINE (pitch_notename, "ly:pitch-notename",
  85            1, 0, 0, (SCM pp),
  86            "Extract the note name from pitch @var{pp}.")
  87 {
  88   LY_ASSERT_SMOB (Pitch, pp, 1);
  89   Pitch *p = unsmob_pitch (pp);
  90   int q = p->get_notename ();
  91   return scm_from_int (q);
  92 }
  93
  94 LY_DEFINE (ly_pitch_quartertones, "ly:pitch-quartertones",
  95            1, 0, 0, (SCM pp),
  96            "Calculate the number of quarter tones of@tie{}@var{pp} from"
  97            " middle@tie{}C.")
  98 {
  99   LY_ASSERT_SMOB (Pitch, pp, 1);
 100   Pitch *p = unsmob_pitch (pp);
 101   int q = p->rounded_quartertone_pitch ();
 102   return scm_from_int (q);
 103 }
 104
 105 LY_DEFINE (ly_pitch_semitones, "ly:pitch-semitones",
 106            1, 0, 0, (SCM pp),
 107            "Calculate the number of semitones 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_semitone_pitch ();
 113   return scm_from_int (q);
 114 }
 115
 116 LY_DEFINE (ly_pitch_less_p, "ly:pitch<?",
 117            2, 0, 0, (SCM p1, SCM p2),
 118            "Is @var{p1} lexicographically smaller than @var{p2}?")
 119 {
 120   LY_ASSERT_SMOB (Pitch, p1, 1);
 121   LY_ASSERT_SMOB (Pitch, p2, 2);
 122
 123   Pitch *a = unsmob_pitch (p1);
 124   Pitch *b = unsmob_pitch (p2);
 125
 126   if (Pitch::compare (*a, *b) < 0)
 127     return SCM_BOOL_T;
 128   else
 129     return SCM_BOOL_F;
 130 }
 131
 132 LY_DEFINE (ly_pitch_diff, "ly:pitch-diff",
 133            2, 0, 0, (SCM pitch, SCM root),
 134            "Return pitch @var{delta} such that @var{pitch} transposed by"
 135            " @var{delta} equals @var{root}.")
 136 {
 137
 138   LY_ASSERT_SMOB (Pitch, pitch, 1);
 139   LY_ASSERT_SMOB (Pitch, root, 2);
 140
 141   Pitch *p = unsmob_pitch (pitch);
 142   Pitch *r = unsmob_pitch (root);
 143
 144   return pitch_interval (*r, *p).smobbed_copy ();
 145 }
 146
 147 /* FIXME: probably isn't the right place for this function */
 148 #include "context.hh"
 149 LY_DEFINE (ly_set_middle_C_x, "ly:set-middle-C!",
 150            1, 0, 0, (SCM context),
 151            "Set the @code{middleCPosition} variable in @var{context}"
 152            " based on the variables @code{middleCClefPosition} and"
 153            " middleCOffset.")
 154 {
 155   LY_ASSERT_SMOB (Context, context, 1);
 156
 157   Context *c = unsmob_context (context);
 158   int clef_pos = robust_scm2int (c->get_property ("middleCClefPosition"), 0);
 159   int offset = robust_scm2int (c->get_property ("middleCOffset"), 0);
 160
 161   c->set_property (ly_symbol2scm ("middleCPosition"), scm_from_int (clef_pos + offset));
 162   return SCM_UNDEFINED;
 163 }