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
 110   if (span_events_[STOP])
 111     {
 112       finished_dynamic_tuples_.top ().audio_->volume_ = last_volume_;
 113     }
 114
 115   if (span_events_[START])
 116     {
 117       dynamic_tuples_[0].audio_->volume_ = last_volume_;
 118     }
 119   span_start_event_ = 0;
 120   span_events_[START] = 0;
 121   span_events_[STOP] = 0;
 122 }
 123
 124 void
 125 Span_dynamic_performer::stop_translation_timestep ()
 126 {
 127   if (finished_dynamic_tuples_.size () > 1)
 128     {
 129       Real start_volume = finished_dynamic_tuples_[0].audio_->volume_;
 130       Real dv = finished_dynamic_tuples_.top ().audio_->volume_
 131         - start_volume;
 132       /*
 133         urg.
 134         Catch and fix the case of:
 135
 136              |                         |
 137             x|                        x|
 138             f cresc.  -- -- -- -- --  pp
 139
 140          Actually, we should provide a non-displayed dynamic/volume setting,
 141          to set volume to 'ff' just before the pp.
 142        */
 143       if (!dv || sign (dv) != finished_dir_)
 144         {
 145           // urg.  20%: about two volume steps
 146           dv = (Real)finished_dir_ * 0.2;
 147           if (!start_volume)
 148             start_volume = finished_dynamic_tuples_.top
 149  ().audio_->volume_ - dv;
 150         }
 151       Moment start_mom = finished_dynamic_tuples_[0].mom_;
 152       Moment dt = finished_dynamic_tuples_.top ().mom_ - start_mom;
 153       for (int i=0; i < finished_dynamic_tuples_.size (); i++)
 154         {
 155           Audio_dynamic_tuple* a = &finished_dynamic_tuples_[i];
 156           Real volume = start_volume + dv * (Real) (a->mom_ - start_mom).main_part_
 157             / (Real)dt.main_part_;
 158           a->audio_->volume_ = volume;
 159         }
 160       finished_dynamic_tuples_.clear ();
 161     }
 162
 163   if (audio_)
 164     {
 165       play_element (audio_);
 166       audio_ = 0;
 167     }
 168
 169   span_events_[STOP] = 0;
 170   span_events_[START] = 0;
 171
 172 }
 173
 174 bool
 175 Span_dynamic_performer::try_music (Music* r)
 176 {
 177   if (r->is_mus_type ("crescendo-event")
 178       || r->is_mus_type ("decrescendo-event"))
 179     {
 180       Direction d = to_dir (r->get_property ("span-direction"));
 181       span_events_[d] = r;
 182       return true;
 183     }
 184   return false;
 185 }
 186 ENTER_DESCRIPTION (Span_dynamic_performer,
 187                    "", "",
 188                    "crescendo-event decrescendo-event",
 189                    "", "", "");