lily/collision-engraver.cc

   1 /*
   2   collision-reg.cc -- implement Collision_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8
   9 #include "note-column.hh"
  10 #include "note-collision.hh"
  11
  12 #include "engraver.hh"
  13 #include "axis-group-interface.hh"
  14
  15 /*
  16   collect Note_column, and as soon as there are 2 or more, put them in
  17   a collision object.  */
  18 class Collision_engraver : public Engraver
  19 {
  20   Item * col_;
  21   Link_array<Grob> note_columns_;
  22
  23 protected:
  24   virtual void acknowledge_grob (Grob_info);
  25   virtual void process_acknowledged_grobs ();
  26   virtual void stop_translation_timestep ();
  27 public:
  28   TRANSLATOR_DECLARATIONS (Collision_engraver);
  29 };
  30
  31
  32 void
  33 Collision_engraver::process_acknowledged_grobs ()
  34 {
  35   if (col_ || note_columns_.size () < 2)
  36     return ;
  37   if (!col_)
  38     {
  39       col_ = make_item ("NoteCollision", SCM_EOL);
  40
  41     }
  42
  43   for (int i=0; i< note_columns_.size (); i++)
  44     Note_collision_interface::add_column (col_,note_columns_[i]);
  45 }
  46
  47 void
  48 Collision_engraver::acknowledge_grob (Grob_info i)
  49 {
  50   if (Note_column::has_interface (i.grob_))
  51     {
  52       /*should check Y axis? */
  53       if (Note_column::has_rests (i.grob_) || i.grob_->get_parent (X_AXIS))
  54         return ;
  55
  56       note_columns_.push (i.grob_);
  57     }
  58 }
  59
  60 void
  61 Collision_engraver::stop_translation_timestep ()
  62 {
  63   col_ =0;
  64   note_columns_.clear ();
  65 }
  66
  67 Collision_engraver::Collision_engraver ()
  68 {
  69   col_ =0;
  70 }
  71
  72
  73
  74
  75 ENTER_DESCRIPTION (Collision_engraver,
  76 /* descr */       "",
  77 /* creats*/       "NoteCollision",
  78 /* accepts */     "",
  79 /* acks  */      "note-column-interface",
  80 /* reads */       "",
  81 /* write */       "");