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--2002 Jan Nieuwenhuizen <janneke@gnu.org>
   7 */
   8
   9 #include "lily-guile.hh"
  10 #include "command-request.hh"
  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_req* 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       proc = scm_primitive_eval (ly_symbol2scm ("major-key"));
  51
  52       Pitch my_do (0,
  53                    gh_scm2int (ly_caar (pitchlist)),
  54                    gh_scm2int (ly_cdar (pitchlist)));
  55
  56       Pitch to_c (-1,
  57                    (7 - gh_scm2int (ly_caar (pitchlist))) % 7,
  58                    -gh_scm2int (ly_cdar (pitchlist)));
  59
  60       my_do.transpose (to_c);
  61       to_c.alteration_ -= my_do.alteration_;
  62
  63       Key_change_req *key = new Key_change_req;
  64       key->set_mus_property ("pitch-alist", scm_list_copy (pitchlist));
  65       ((Music*)key)->transpose (to_c);
  66       SCM c_pitchlist = key->get_mus_property ("pitch-alist");
  67       SCM major = gh_call1 (proc, c_pitchlist);
  68
  69       audio_ = new Audio_key (gh_scm2int (acc), major == SCM_BOOL_T);
  70       Audio_element_info info (audio_, key_req_);
  71       announce_element (info);
  72       key_req_ = 0;
  73     }
  74 }
  75
  76 void
  77 Key_performer::stop_translation_timestep ()
  78 {
  79   if (audio_)
  80     {
  81       play_element (audio_);
  82       audio_ = 0;
  83     }
  84 }
  85
  86 bool
  87 Key_performer::try_music (Music* req)
  88 {
  89   if (Key_change_req *kc = dynamic_cast <Key_change_req *> (req))
  90     {
  91       if (key_req_)
  92         warning (_ ("FIXME: key change merge"));
  93
  94       key_req_ = kc;
  95       return true;
  96     }
  97
  98   return false;
  99 }
 100
 101 ENTER_DESCRIPTION(Key_performer,"","","","","");