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--2006 Jan Nieuwenhuizen <janneke@gnu.org>
   7 */
   8
   9 #include "performer.hh"
  10
  11 #include "audio-item.hh"
  12 #include "international.hh"
  13 #include "music.hh"
  14
  15 /*
  16   TODO: fold this into 1 engraver: \< and \> should also stop when
  17   absdyn is encountered.
  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   void process_music ();
  37   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   vector<Audio_dynamic_tuple> dynamic_tuples_;
  45   vector<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     last_volume_ = d->volume_;
  64 }
  65
  66 void
  67 Span_dynamic_performer::process_music ()
  68 {
  69   if (span_start_event_ || span_events_[START])
  70     {
  71       audio_ = new Audio_dynamic (0);
  72       Audio_element_info info (audio_, span_events_[START]
  73                                ? span_events_[START]
  74                                : span_events_[STOP]);
  75       announce_element (info);
  76       Audio_dynamic_tuple a = { audio_, now_mom () };
  77       dynamic_tuples_.push_back (a);
  78     }
  79
  80   if (span_events_[STOP])
  81     {
  82       if (!span_start_event_)
  83         {
  84           span_events_[STOP]->origin ()->warning (_ ("can't find start of (de)crescendo"));
  85           span_events_[STOP] = 0;
  86         }
  87       else
  88         {
  89           finished_dir_ = dir_;
  90           finished_dynamic_tuples_ = dynamic_tuples_;
  91         }
  92       dynamic_tuples_.clear ();
  93       span_start_event_ = 0;
  94     }
  95
  96   if (span_events_[START])
  97     {
  98       dir_ = (span_events_[START]->is_mus_type ("crescendo-event"))
  99         ? RIGHT : LEFT;
 100       span_start_event_ = span_events_[START];
 101
 102       dynamic_tuples_.clear ();
 103       Audio_dynamic_tuple a = { audio_, now_mom () };
 104       dynamic_tuples_.push_back (a);
 105     }
 106
 107   if (span_events_[STOP])
 108     finished_dynamic_tuples_.back ().audio_->volume_ = last_volume_;
 109
 110   if (span_events_[START])
 111     dynamic_tuples_[0].audio_->volume_ = last_volume_;
 112
 113   span_events_[START] = 0;
 114   span_events_[STOP] = 0;
 115 }
 116
 117 void
 118 Span_dynamic_performer::stop_translation_timestep ()
 119 {
 120   if (finished_dynamic_tuples_.size () > 1)
 121     {
 122       Real start_volume = finished_dynamic_tuples_[0].audio_->volume_;
 123       Real dv = finished_dynamic_tuples_.back ().audio_->volume_
 124         - start_volume;
 125       /*
 126         urg.
 127         Catch and fix the case of:
 128
 129         |                         |
 130         x|                        x|
 131         f cresc.  -- -- -- -- --  pp
 132
 133         Actually, we should provide a non-displayed dynamic/volume setting,
 134         to set volume to 'ff' just before the pp.
 135       */
 136       if (!dv || sign (dv) != finished_dir_)
 137         {
 138           // urg.  20%: about two volume steps
 139           dv = (Real)finished_dir_ * 0.2;
 140           if (!start_volume)
 141             start_volume = finished_dynamic_tuples_.back ().audio_->volume_
 142               - dv;
 143         }
 144       Moment start_mom = finished_dynamic_tuples_[0].mom_;
 145       Moment dt = finished_dynamic_tuples_.back ().mom_ - start_mom;
 146       for (vsize i = 0; i < finished_dynamic_tuples_.size (); i++)
 147         {
 148           Audio_dynamic_tuple *a = &finished_dynamic_tuples_[i];
 149           Real volume = start_volume + dv * (Real) (a->mom_ - start_mom).main_part_
 150             / (Real)dt.main_part_;
 151           a->audio_->volume_ = volume;
 152         }
 153       finished_dynamic_tuples_.clear ();
 154     }
 155
 156   if (audio_)
 157     {
 158       play_element (audio_);
 159       audio_ = 0;
 160     }
 161
 162   span_events_[STOP] = 0;
 163   span_events_[START] = 0;
 164 }
 165
 166 bool
 167 Span_dynamic_performer::try_music (Music *r)
 168 {
 169   if (r->is_mus_type ("crescendo-event")
 170       || r->is_mus_type ("decrescendo-event"))
 171     {
 172       Direction d = to_dir (r->get_property ("span-direction"));
 173       span_events_[d] = r;
 174       return true;
 175     }
 176   return false;
 177 }
 178 #include "translator.icc"
 179
 180 ADD_TRANSLATOR (Span_dynamic_performer,
 181                 "", "",
 182                 "crescendo-event decrescendo-event",
 183                 "", "");