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--2008 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 from 0"
  29            " to@tie{}6, with 0 corresponding to pitch@tie{}C and 6"
  30            " corresponding to pitch@tie{}B.  @var{alter} is a rational"
  31            " number of whole tones for alteration.")
  32 {
  33   LY_ASSERT_TYPE (scm_is_integer, octave, 1);
  34   LY_ASSERT_TYPE (scm_is_integer, note, 2);
  35   LY_ASSERT_TYPE (scm_is_rational, alter, 3);
  36
  37   Pitch p (scm_to_int (octave), scm_to_int (note),
  38            ly_scm2rational (alter));
  39
  40   return p.smobbed_copy ();
  41 }
  42
  43 LY_DEFINE (ly_pitch_negate, "ly:pitch-negate", 1, 0, 0,
  44            (SCM p),
  45            "Negate @var{p}.")
  46 {
  47   LY_ASSERT_SMOB (Pitch, p, 1);
  48   Pitch *pp = unsmob_pitch (p);
  49   return pp->negated ().smobbed_copy ();
  50 }
  51
  52 LY_DEFINE (ly_pitch_steps, "ly:pitch-steps", 1, 0, 0,
  53            (SCM p),
  54            "Number of steps counted from middle@tie{}C of the"
  55            " pitch@tie{}@var{p}.")
  56 {
  57   LY_ASSERT_SMOB (Pitch, p, 1);
  58   Pitch *pp = unsmob_pitch (p);
  59   return scm_from_int (pp->steps ());
  60 }
  61
  62 LY_DEFINE (ly_pitch_octave, "ly:pitch-octave",
  63            1, 0, 0, (SCM pp),
  64            "Extract the octave from pitch@tie{}@var{pp}.")
  65 {
  66   LY_ASSERT_SMOB (Pitch, pp, 1);
  67   Pitch *p = unsmob_pitch (pp);
  68   int q = p->get_octave ();
  69   return scm_from_int (q);
  70 }
  71
  72 LY_DEFINE (ly_pitch_alteration, "ly:pitch-alteration",
  73            1, 0, 0, (SCM pp),
  74            "Extract the alteration from pitch@tie{}@var{pp}.")
  75 {
  76   LY_ASSERT_SMOB (Pitch, pp, 1);
  77   Pitch *p = unsmob_pitch (pp);
  78   Rational q = p->get_alteration ();
  79
  80   return ly_rational2scm (q);
  81 }
  82
  83 LY_DEFINE (pitch_notename, "ly:pitch-notename",
  84            1, 0, 0, (SCM pp),
  85            "Extract the note name from pitch @var{pp}.")
  86 {
  87   LY_ASSERT_SMOB (Pitch, pp, 1);
  88   Pitch *p = unsmob_pitch (pp);
  89   int q = p->get_notename ();
  90   return scm_from_int (q);
  91 }
  92
  93 LY_DEFINE (ly_pitch_quartertones, "ly:pitch-quartertones",
  94            1, 0, 0, (SCM pp),
  95            "Calculate the number of quarter tones of@tie{}@var{pp} from"
  96            " middle@tie{}C.")
  97 {
  98   LY_ASSERT_SMOB (Pitch, pp, 1);
  99   Pitch *p = unsmob_pitch (pp);
 100   int q = p->rounded_quartertone_pitch ();
 101   return scm_from_int (q);
 102 }
 103
 104 LY_DEFINE (ly_pitch_semitones, "ly:pitch-semitones",
 105            1, 0, 0, (SCM pp),
 106            "Calculate the number of semitones of@tie{}@var{pp} from"
 107            " middle@tie{}C.")
 108 {
 109   LY_ASSERT_SMOB (Pitch, pp, 1);
 110   Pitch *p = unsmob_pitch (pp);
 111   int q = p->rounded_semitone_pitch ();
 112   return scm_from_int (q);
 113 }
 114
 115 LY_DEFINE (ly_pitch_less_p, "ly:pitch<?",
 116            2, 0, 0, (SCM p1, SCM p2),
 117            "Is @var{p1} lexicographically smaller than @var{p2}?")
 118 {
 119   LY_ASSERT_SMOB (Pitch, p1, 1);
 120   LY_ASSERT_SMOB (Pitch, p2, 2);
 121
 122   Pitch *a = unsmob_pitch (p1);
 123   Pitch *b = unsmob_pitch (p2);
 124
 125   if (Pitch::compare (*a, *b) < 0)
 126     return SCM_BOOL_T;
 127   else
 128     return SCM_BOOL_F;
 129 }
 130
 131 LY_DEFINE (ly_pitch_diff, "ly:pitch-diff",
 132            2, 0, 0, (SCM pitch, SCM root),
 133            "Return pitch @var{delta} such that @var{pitch} transposed by"
 134            " @var{delta} equals @var{root}.")
 135 {
 136
 137   LY_ASSERT_SMOB (Pitch, pitch, 1);
 138   LY_ASSERT_SMOB (Pitch, root, 2);
 139
 140   Pitch *p = unsmob_pitch (pitch);
 141   Pitch *r = unsmob_pitch (root);
 142
 143   return pitch_interval (*r, *p).smobbed_copy ();
 144 }
 145
 146 /* FIXME: probably isn't the right place for this function */
 147 #include "context.hh"
 148 LY_DEFINE (ly_set_middle_C_x, "ly:set-middle-C!",
 149            1, 0, 0, (SCM context),
 150            "Set the @code{middleCPosition} variable in @var{context}"
 151            " based on the variables @code{middleCClefPosition} and"
 152            " middleCOffset.")
 153 {
 154   LY_ASSERT_SMOB (Context, context, 1);
 155
 156   Context *c = unsmob_context (context);
 157   int clef_pos = robust_scm2int (c->get_property ("middleCClefPosition"), 0);
 158   int offset = robust_scm2int (c->get_property ("middleCOffset"), 0);
 159
 160   c->set_property (ly_symbol2scm ("middleCPosition"), scm_from_int (clef_pos + offset));
 161   return SCM_UNDEFINED;
 162 }