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