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--2005 Jan Nieuwenhuizen <janneke@gnu.org>
   7 */
   8
   9 #include "performer.hh"
  10 #include "audio-item.hh"
  11
  12 /*
  13   TODO: fold this into 1 engraver: \< and \> should also stop when
  14   absdyn is encountered.
  15 */
  16 struct Audio_dynamic_tuple
  17 {
  18   Audio_dynamic *audio_;
  19   Moment mom_;
  20 };
  21
  22 /**
  23    perform span-dynamics
  24 */
  25 class Span_dynamic_performer : public Performer
  26 {
  27 public:
  28   TRANSLATOR_DECLARATIONS (Span_dynamic_performer);
  29
  30 protected:
  31   virtual bool try_music (Music *);
  32   virtual void acknowledge_audio_element (Audio_element_info);
  33   virtual void process_music ();
  34   virtual void stop_translation_timestep ();
  35
  36 private:
  37   Audio_dynamic *audio_;
  38   Real last_volume_;
  39   Music *span_start_event_;
  40   Drul_array<Music *> span_events_;
  41   Array<Audio_dynamic_tuple> dynamic_tuples_;
  42   Array<Audio_dynamic_tuple> finished_dynamic_tuples_;
  43   Direction dir_;
  44   Direction finished_dir_;
  45 };
  46
  47 Span_dynamic_performer::Span_dynamic_performer ()
  48 {
  49   span_events_[START] = 0;
  50   span_events_[STOP] = 0;
  51   span_start_event_ = 0;
  52   audio_ = 0;
  53   last_volume_ = 0;
  54 }
  55
  56 void
  57 Span_dynamic_performer::acknowledge_audio_element (Audio_element_info i)
  58 {
  59   if (Audio_dynamic *d = dynamic_cast<Audio_dynamic *> (i.elem_))
  60     {
  61       last_volume_ = d->volume_;
  62     }
  63 }
  64
  65 void
  66 Span_dynamic_performer::process_music ()
  67 {
  68   if (span_start_event_ || span_events_[START])
  69     {
  70       audio_ = new Audio_dynamic (0);
  71       Audio_element_info info (audio_, span_events_[START]
  72                                ? span_events_[START]
  73                                : span_events_[STOP]);
  74       announce_element (info);
  75       Audio_dynamic_tuple a = { audio_, now_mom () };
  76       dynamic_tuples_.push (a);
  77     }
  78
  79   if (span_events_[STOP])
  80     {
  81       if (!span_start_event_)
  82         {
  83           span_events_[STOP]->origin ()->warning (_ ("can't find start of (de)crescendo"));
  84           span_events_[STOP] = 0;
  85         }
  86       else
  87         {
  88           finished_dir_ = dir_;
  89           finished_dynamic_tuples_ = dynamic_tuples_;
  90         }
  91       dynamic_tuples_.clear ();
  92       span_start_event_ = 0;
  93     }
  94
  95   if (span_events_[START])
  96     {
  97       dir_ = (span_events_[START]->is_mus_type ("crescendo-event"))
  98         ? RIGHT : LEFT;
  99       span_start_event_ = span_events_[START];
 100
 101       dynamic_tuples_.clear ();
 102       Audio_dynamic_tuple a = { audio_, now_mom () };
 103       dynamic_tuples_.push (a);
 104     }
 105
 106   if (span_events_[STOP])
 107     {
 108       finished_dynamic_tuples_.top ().audio_->volume_ = last_volume_;
 109     }
 110
 111   if (span_events_[START])
 112     {
 113       dynamic_tuples_[0].audio_->volume_ = last_volume_;
 114     }
 115
 116   span_events_[START] = 0;
 117   span_events_[STOP] = 0;
 118 }
 119
 120 void
 121 Span_dynamic_performer::stop_translation_timestep ()
 122 {
 123   if (finished_dynamic_tuples_.size () > 1)
 124     {
 125       Real start_volume = finished_dynamic_tuples_[0].audio_->volume_;
 126       Real dv = finished_dynamic_tuples_.top ().audio_->volume_
 127         - start_volume;
 128       /*
 129         urg.
 130         Catch and fix the case of:
 131
 132         |                         |
 133         x|                        x|
 134         f cresc.  -- -- -- -- --  pp
 135
 136         Actually, we should provide a non-displayed dynamic/volume setting,
 137         to set volume to 'ff' just before the pp.
 138       */
 139       if (!dv || sign (dv) != finished_dir_)
 140         {
 141           // urg.  20%: about two volume steps
 142           dv = (Real)finished_dir_ * 0.2;
 143           if (!start_volume)
 144             start_volume = finished_dynamic_tuples_.top
 145               ().audio_->volume_ - dv;
 146         }
 147       Moment start_mom = finished_dynamic_tuples_[0].mom_;
 148       Moment dt = finished_dynamic_tuples_.top ().mom_ - start_mom;
 149       for (int i = 0; i < finished_dynamic_tuples_.size (); i++)
 150         {
 151           Audio_dynamic_tuple *a = &finished_dynamic_tuples_[i];
 152           Real volume = start_volume + dv * (Real) (a->mom_ - start_mom).main_part_
 153             / (Real)dt.main_part_;
 154           a->audio_->volume_ = volume;
 155         }
 156       finished_dynamic_tuples_.clear ();
 157     }
 158
 159   if (audio_)
 160     {
 161       play_element (audio_);
 162       audio_ = 0;
 163     }
 164
 165   span_events_[STOP] = 0;
 166   span_events_[START] = 0;
 167 }
 168
 169 bool
 170 Span_dynamic_performer::try_music (Music *r)
 171 {
 172   if (r->is_mus_type ("crescendo-event")
 173       || r->is_mus_type ("decrescendo-event"))
 174     {
 175       Direction d = to_dir (r->get_property ("span-direction"));
 176       span_events_[d] = r;
 177       return true;
 178     }
 179   return false;
 180 }
 181 ADD_TRANSLATOR (Span_dynamic_performer,
 182                 "", "",
 183                 "crescendo-event decrescendo-event",
 184                 "", "", "");