lily/span-dynamic-performer.cc

   1 /*
   2   span-dynamic-performer.cc -- implement Span_dynamic_performer
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2000--2004 Jan Nieuwenhuizen <janneke@gnu.org>
   7 */
   8
   9 #include "performer.hh"
  10
  11 #include "event.hh"
  12 #include "audio-item.hh"
  13
  14 /*
  15   TODO: fold this into 1 engraver: \< and \> should also stop when
  16   absdyn is encountered.
  17  */
  18
  19 struct Audio_dynamic_tuple
  20 {
  21   Audio_dynamic* audio_;
  22   Moment mom_;
  23 };
  24
  25 /**
  26    perform span-dynamics
  27  */
  28 class Span_dynamic_performer : public Performer
  29 {
  30 public:
  31   TRANSLATOR_DECLARATIONS (Span_dynamic_performer);
  32
  33 protected:
  34   virtual bool try_music (Music*);
  35   virtual void acknowledge_audio_element (Audio_element_info);
  36   virtual void process_music ();
  37   virtual void stop_translation_timestep ();
  38
  39 private:
  40   Audio_dynamic* audio_;
  41   Real last_volume_;
  42   Music* span_start_event_;
  43   Drul_array<Music*> span_events_;
  44   Array<Audio_dynamic_tuple> dynamic_tuples_;
  45   Array<Audio_dynamic_tuple> finished_dynamic_tuples_;
  46   Direction dir_;
  47   Direction finished_dir_;
  48 };
  49
  50 Span_dynamic_performer::Span_dynamic_performer ()
  51 {
  52   span_events_[START] = 0;
  53   span_events_[STOP] = 0;
  54   span_start_event_ = 0;
  55   audio_ = 0;
  56   last_volume_ = 0;
  57 }
  58
  59 void
  60 Span_dynamic_performer::acknowledge_audio_element (Audio_element_info i)
  61 {
  62   if (Audio_dynamic * d = dynamic_cast <Audio_dynamic*> (i.elem_))
  63     {
  64       last_volume_ = d->volume_;
  65     }
  66 }
  67
  68 void
  69 Span_dynamic_performer::process_music ()
  70 {
  71   if (span_start_event_ || span_events_[START])
  72     {
  73       audio_ = new Audio_dynamic (0);
  74       Audio_element_info info (audio_, span_events_[START]
  75                                ? span_events_[START]
  76                                : span_events_[STOP]);
  77       announce_element (info);
  78       Audio_dynamic_tuple a = { audio_, now_mom () };
  79       dynamic_tuples_.push (a);
  80     }
  81
  82   if (span_events_[STOP])
  83     {
  84       if (!span_start_event_)
  85         {
  86           span_events_[STOP]->origin ()->warning (_ ("can't find start of (de)crescendo"));
  87           span_events_[STOP] = 0;
  88         }
  89       else
  90         {
  91           finished_dir_ = dir_;
  92           finished_dynamic_tuples_ = dynamic_tuples_;
  93         }
  94       dynamic_tuples_.clear ();
  95       span_start_event_ = 0;
  96     }
  97
  98   if (span_events_[START])
  99     {
 100       dir_ =  (span_events_[START]->is_mus_type ("crescendo-event"))
 101         ? RIGHT : LEFT;
 102       span_start_event_ = span_events_[START];
 103
 104       dynamic_tuples_.clear ();
 105       Audio_dynamic_tuple a = { audio_, now_mom () };
 106       dynamic_tuples_.push (a);
 107     }
 108
 109   if (span_events_[STOP])
 110     {
 111       finished_dynamic_tuples_.top ().audio_->volume_ = last_volume_;
 112     }
 113
 114   if (span_events_[START])
 115     {
 116       dynamic_tuples_[0].audio_->volume_ = last_volume_;
 117     }
 118
 119   span_events_[START] = 0;
 120   span_events_[STOP] = 0;
 121 }
 122
 123 void
 124 Span_dynamic_performer::stop_translation_timestep ()
 125 {
 126   if (finished_dynamic_tuples_.size () > 1)
 127     {
 128       Real start_volume = finished_dynamic_tuples_[0].audio_->volume_;
 129       Real dv = finished_dynamic_tuples_.top ().audio_->volume_
 130         - start_volume;
 131       /*
 132         urg.
 133         Catch and fix the case of:
 134
 135              |                         |
 136             x|                        x|
 137             f cresc.  -- -- -- -- --  pp
 138
 139          Actually, we should provide a non-displayed dynamic/volume setting,
 140          to set volume to 'ff' just before the pp.
 141        */
 142       if (!dv || sign (dv) != finished_dir_)
 143         {
 144           // urg.  20%: about two volume steps
 145           dv = (Real)finished_dir_ * 0.2;
 146           if (!start_volume)
 147             start_volume = finished_dynamic_tuples_.top
 148  ().audio_->volume_ - dv;
 149         }
 150       Moment start_mom = finished_dynamic_tuples_[0].mom_;
 151       Moment dt = finished_dynamic_tuples_.top ().mom_ - start_mom;
 152       for (int i=0; i < finished_dynamic_tuples_.size (); i++)
 153         {
 154           Audio_dynamic_tuple* a = &finished_dynamic_tuples_[i];
 155           Real volume = start_volume + dv * (Real) (a->mom_ - start_mom).main_part_
 156             / (Real)dt.main_part_;
 157           a->audio_->volume_ = volume;
 158         }
 159       finished_dynamic_tuples_.clear ();
 160     }
 161
 162   if (audio_)
 163     {
 164       play_element (audio_);
 165       audio_ = 0;
 166     }
 167
 168   span_events_[STOP] = 0;
 169   span_events_[START] = 0;
 170
 171 }
 172
 173 bool
 174 Span_dynamic_performer::try_music (Music* r)
 175 {
 176   if (r->is_mus_type ("crescendo-event")
 177       || r->is_mus_type ("decrescendo-event"))
 178     {
 179       Direction d = to_dir (r->get_property ("span-direction"));
 180       span_events_[d] = r;
 181       return true;
 182     }
 183   return false;
 184 }
 185 ENTER_DESCRIPTION (Span_dynamic_performer,
 186                    "", "",
 187                    "crescendo-event decrescendo-event",
 188                    "", "", "");