lily/key-performer.cc

   1 /*
   2   key-performer.cc -- implement Key_performer
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c)  1997--2003 Jan Nieuwenhuizen <janneke@gnu.org>
   7 */
   8
   9 #include "lily-guile.hh"
  10
  11 #include "audio-item.hh"
  12 #include "performer.hh"
  13 #include "warn.hh"
  14
  15
  16 class Key_performer : public Performer
  17 {
  18 public:
  19   TRANSLATOR_DECLARATIONS(Key_performer);
  20   ~Key_performer ();
  21
  22 protected:
  23   virtual bool try_music (Music* req);
  24   virtual void create_audio_elements ();
  25   virtual void stop_translation_timestep ();
  26
  27 private:
  28   Key_change_ev* key_req_;
  29   Audio_key* audio_;
  30 };
  31
  32 Key_performer::Key_performer ()
  33 {
  34   key_req_ = 0;
  35   audio_ = 0;
  36 }
  37
  38 Key_performer::~Key_performer ()
  39 {
  40 }
  41
  42 void
  43 Key_performer::create_audio_elements ()
  44 {
  45   if (key_req_)
  46     {
  47       SCM pitchlist = key_req_->get_mus_property ("pitch-alist");
  48       SCM proc = scm_primitive_eval (ly_symbol2scm ("accidentals-in-key"));
  49       SCM acc = gh_call1 (proc, pitchlist);
  50
  51       Pitch key_do (0,
  52                     gh_scm2int (ly_caar (pitchlist)),
  53                     gh_scm2int (ly_cdar (pitchlist)));
  54
  55       Pitch c_do (0, 0, 0);
  56
  57       SCM c_pitchlist
  58         = ly_transpose_key_alist (pitchlist,
  59                                   interval (key_do, c_do).smobbed_copy ());
  60
  61       /* MIDI keys are too limited for lilypond scales.
  62          We check for minor scale and assume major otherwise.  */
  63       SCM minor = scm_primitive_eval (ly_symbol2scm ("minor"));
  64       audio_ = new Audio_key (gh_scm2int (acc),
  65                               SCM_BOOL_T != scm_equal_p (minor, c_pitchlist));
  66
  67       Audio_element_info info (audio_, key_req_);
  68       announce_element (info);
  69       key_req_ = 0;
  70     }
  71 }
  72
  73 void
  74 Key_performer::stop_translation_timestep ()
  75 {
  76   if (audio_)
  77     {
  78       play_element (audio_);
  79       audio_ = 0;
  80     }
  81 }
  82
  83 bool
  84 Key_performer::try_music (Music* req)
  85 {
  86   if (Key_change_ev *kc = dynamic_cast <Key_change_ev *> (req))
  87     {
  88       if (key_req_)
  89         warning (_ ("FIXME: key change merge"));
  90
  91       key_req_ = kc;
  92       return true;
  93     }
  94
  95   return false;
  96 }
  97
  98 ENTER_DESCRIPTION(Key_performer,
  99                   "","",
 100                   "key-change-event",
 101                   "","","");