lily/piano-pedal-bracket.cc

   1 /*
   2   piano-pedal-bracket.cc --  implement  Piano_pedal_bracket
   3
   4 source file of the GNU LilyPond music typesetter
   5
   6 (c) 2003 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7
   8 based on smouldering remains by
   9
  10    Chris Jackson <chris@fluffhouse.org.uk>
  11
  12
  13 */
  14 /*
  15    Piano pedal brackets are a special case of a text spanner.
  16    Pedal up-down (restart) indicated by the angled right and left edges
  17    of consecutive pedals touching exactly to form an __/\__
  18
  19 */
  20
  21
  22 /*
  23   TODO: this should be moved somewhere else (?).
  24
  25   Perhaps make separate function for pedal-bracket.
  26  */
  27 #include "molecule.hh"
  28 #include "spanner.hh"
  29 #include "item.hh"
  30 #include "paper-def.hh"
  31
  32 struct Piano_pedal_bracket
  33 {
  34   DECLARE_SCHEME_CALLBACK(after_line_breaking,(SCM));
  35   static bool has_interface (Grob*);
  36 };
  37
  38 ADD_INTERFACE (Piano_pedal_bracket,"piano-pedal-bracket-interface",
  39                "",
  40                "pedal-text");
  41
  42 MAKE_SCHEME_CALLBACK(Piano_pedal_bracket,after_line_breaking,1);
  43 SCM
  44 Piano_pedal_bracket::after_line_breaking (SCM smob)
  45 {
  46   Spanner *me = dynamic_cast<Spanner*> (unsmob_grob (smob));
  47
  48   Drul_array<bool> broken;
  49   Drul_array<Real> height(0,0), shorten(0,0);
  50
  51   SCM eh = me->get_grob_property ("edge-height");
  52   SCM sp = me->get_grob_property ("shorten-pair");
  53
  54   Direction d = LEFT;
  55
  56   do
  57     {
  58       Item *b = me->get_bound (d);
  59       broken[d] = b->break_status_dir () != CENTER;
  60
  61       if (!broken[d] && (is_number_pair (eh)))
  62         height[d] += gh_scm2double (index_get_cell (eh, d));
  63       if (is_number_pair (sp))
  64         shorten[d] +=  gh_scm2double (index_get_cell (sp, d));
  65     }
  66   while (flip (&d) != LEFT);
  67
  68   /* For 'Mixed' style pedals, i.e.  a bracket preceded by text:  Ped._____|
  69    need to shorten by the extent of the text grob
  70
  71
  72    Urg. - why not hang bracket between text items? --hwn
  73   */
  74   if (Grob *textbit = unsmob_grob (me->get_grob_property("pedal-text")))
  75     {
  76       height[LEFT] = 0;
  77       SCM pa = me->get_grob_property ("if-text-padding"); // UGH.
  78       Real padding =0.;
  79       if (gh_number_p (pa))
  80         padding = gh_scm2double (pa);
  81
  82       shorten[LEFT] += padding + textbit->extent (textbit, X_AXIS)[RIGHT];
  83     }
  84
  85   if (broken[LEFT])
  86     {
  87       shorten[LEFT]  -=  me->get_broken_left_end_align () ;
  88     }
  89
  90   // Also shorten so that it ends just before the spanned note.
  91   Grob  *rb = me->get_bound (RIGHT);
  92   shorten[RIGHT]  += rb->extent (rb, X_AXIS)[RIGHT];
  93
  94   me->set_grob_property ("edge-height", ly_interval2scm (height));
  95   me->set_grob_property ("shorten-pair", ly_interval2scm (shorten));
  96
  97   return SCM_UNSPECIFIED;
  98 }
  99