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 struct Audio_dynamic_tuple
  15 {
  16   Audio_dynamic* audio_;
  17   Moment mom_;
  18 };
  19
  20 /**
  21    perform span-dynamics
  22  */
  23 class Span_dynamic_performer : public Performer
  24 {
  25 public:
  26   TRANSLATOR_DECLARATIONS(Span_dynamic_performer);
  27
  28 protected:
  29   virtual bool try_music (Music*);
  30   virtual void acknowledge_audio_element (Audio_element_info);
  31   virtual void process_music ();
  32   virtual void stop_translation_timestep ();
  33
  34 private:
  35   Audio_dynamic* audio_;
  36   Real last_volume_;
  37   Music* span_start_req_;
  38   Drul_array<Music*> span_req_l_drul_;
  39   Array<Audio_dynamic_tuple> dynamic_tuples_;
  40   Array<Audio_dynamic_tuple> finished_dynamic_tuples_;
  41   Direction dir_;
  42   Direction finished_dir_;
  43 };
  44
  45 Span_dynamic_performer::Span_dynamic_performer ()
  46 {
  47   span_req_l_drul_[START] = 0;
  48   span_req_l_drul_[STOP] = 0;
  49   span_start_req_ = 0;
  50   audio_ = 0;
  51   last_volume_ = 0;
  52 }
  53
  54 void
  55 Span_dynamic_performer::acknowledge_audio_element (Audio_element_info i)
  56 {
  57   if (Audio_dynamic * d = dynamic_cast <Audio_dynamic*> (i.elem_))
  58     {
  59       last_volume_ = d->volume_;
  60     }
  61 }
  62
  63 void
  64 Span_dynamic_performer::process_music ()
  65 {
  66   if (span_start_req_ || span_req_l_drul_[START])
  67     {
  68       audio_ = new Audio_dynamic (0);
  69       Audio_element_info info (audio_, span_req_l_drul_[START]
  70                                ? span_req_l_drul_[START]
  71                                : span_req_l_drul_[STOP]);
  72       announce_element (info);
  73       Audio_dynamic_tuple a = { audio_, now_mom () };
  74       dynamic_tuples_.push (a);
  75     }
  76
  77   if (span_req_l_drul_[STOP])
  78     {
  79       if (!span_start_req_)
  80         {
  81           span_req_l_drul_[STOP]->origin ()->warning (_ ("can't find start of (de)crescendo"));
  82           span_req_l_drul_[STOP] = 0;
  83         }
  84       else
  85         {
  86           finished_dir_ = dir_;
  87           finished_dynamic_tuples_ = dynamic_tuples_;
  88         }
  89       dynamic_tuples_.clear ();
  90       span_start_req_ = 0;
  91     }
  92
  93   if (span_req_l_drul_[START])
  94     {
  95       String t = ly_scm2string (span_req_l_drul_[START]->get_mus_property ("span-type"));
  96       dir_ = (t == "crescendo") ? RIGHT : LEFT;
  97       span_start_req_ = span_req_l_drul_[START];
  98
  99       dynamic_tuples_.clear ();
 100       Audio_dynamic_tuple a = { audio_, now_mom () };
 101       dynamic_tuples_.push (a);
 102     }
 103
 104
 105   if (span_req_l_drul_[STOP])
 106     {
 107       finished_dynamic_tuples_.top ().audio_->volume_ = last_volume_;
 108     }
 109
 110   if (span_req_l_drul_[START])
 111     {
 112       dynamic_tuples_[0].audio_->volume_ = last_volume_;
 113     }
 114   span_start_req_ = 0;
 115   span_req_l_drul_[START] = 0;
 116   span_req_l_drul_[STOP] = 0;
 117 }
 118
 119 void
 120 Span_dynamic_performer::stop_translation_timestep ()
 121 {
 122   if (finished_dynamic_tuples_.size () > 1)
 123     {
 124       Real start_volume = finished_dynamic_tuples_[0].audio_->volume_;
 125       Real dv = finished_dynamic_tuples_.top ().audio_->volume_
 126         - start_volume;
 127       /*
 128         urg.
 129         Catch and fix the case of:
 130
 131              |                         |
 132             x|                        x|
 133             f cresc.  -- -- -- -- --  pp
 134
 135          Actually, we should provide a non-displayed dynamic/volume setting,
 136          to set volume to 'ff' just before the pp.
 137        */
 138       if (!dv || sign (dv) != finished_dir_)
 139         {
 140           // urg.  20%: about two volume steps
 141           dv = (Real)finished_dir_ * 0.2;
 142           if (!start_volume)
 143             start_volume = finished_dynamic_tuples_.top
 144  ().audio_->volume_ - dv;
 145         }
 146       Moment start_mom = finished_dynamic_tuples_[0].mom_;
 147       Moment dt = finished_dynamic_tuples_.top ().mom_ - start_mom;
 148       for (int i=0; i < finished_dynamic_tuples_.size (); i++)
 149         {
 150           Audio_dynamic_tuple* a = &finished_dynamic_tuples_[i];
 151           Real volume = start_volume + dv * (Real) (a->mom_ - start_mom).main_part_
 152             / (Real)dt.main_part_;
 153           a->audio_->volume_ = volume;
 154         }
 155       finished_dynamic_tuples_.clear ();
 156     }
 157
 158   if (audio_)
 159     {
 160       play_element (audio_);
 161       audio_ = 0;
 162     }
 163
 164   span_req_l_drul_[STOP] = 0;
 165   span_req_l_drul_[START] = 0;
 166
 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_mus_property ("span-direction"));
 176       span_req_l_drul_[d] = r;
 177       return true;
 178     }
 179   return false;
 180 }
 181 ENTER_DESCRIPTION (Span_dynamic_performer,
 182                    "", "",
 183                    "crescendo-event decrescendo-event",
 184                    "", "", "");