lily/staff-symbol-referencer.cc

   1 /*
   2   staff-symbol-referencer.cc -- implement Staff_symbol_referencer
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1999--2000 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7  */
   8
   9 #include <math.h>
  10
  11 #include "staff-symbol-referencer.hh"
  12 #include "staff-symbol.hh"
  13 #include "paper-def.hh"
  14 #include "dimension-cache.hh"
  15
  16 Staff_symbol_referencer_interface::Staff_symbol_referencer_interface (Score_element const *sc)
  17 {
  18   elt_l_ = (Score_element*)sc;
  19 }
  20
  21 void
  22 Staff_symbol_referencer_interface::set_interface ()
  23 {
  24   if (!gh_number_p (elt_l_->get_elt_property ("staff-position")))
  25       elt_l_->set_elt_property ("staff-position", gh_double2scm (0.0));
  26
  27   elt_l_->add_offset_callback (callback, Y_AXIS);
  28 }
  29
  30 bool
  31 Staff_symbol_referencer_interface::has_interface_b ()
  32 {
  33   return unsmob_element (elt_l_->get_elt_pointer ("staff-symbol"))
  34     || gh_number_p (elt_l_->get_elt_property ("staff-position"));
  35 }
  36
  37
  38 int
  39 Staff_symbol_referencer_interface::line_count () const
  40 {
  41   Staff_symbol *st = staff_symbol_l ();
  42   return st  ?  st->line_count () : 0;
  43 }
  44
  45 Staff_symbol*
  46 Staff_symbol_referencer_interface::staff_symbol_l () const
  47 {
  48   SCM st = elt_l_->get_elt_pointer ("staff-symbol");
  49   return dynamic_cast<Staff_symbol* > (unsmob_element(st));
  50 }
  51
  52 Real
  53 Staff_symbol_referencer_interface::staff_space () const
  54 {
  55   Staff_symbol * st = staff_symbol_l ();
  56   if (st)
  57     return st->staff_space ();
  58   else if (elt_l_->pscore_l_ && elt_l_->paper_l ())
  59     return elt_l_->paper_l ()->get_var ("interline");
  60
  61   return 0.0;
  62 }
  63
  64
  65 Real
  66 Staff_symbol_referencer_interface::position_f () const
  67 {
  68   Real p =0.0;
  69   Staff_symbol * st = staff_symbol_l ();
  70   Score_element * c = st ? elt_l_->common_refpoint (st, Y_AXIS) : 0;
  71   if (st && c)
  72     {
  73       Real y = elt_l_->relative_coordinate (c, Y_AXIS)
  74         - st->relative_coordinate (c, Y_AXIS);
  75
  76       p += 2.0 * y / st->staff_space ();
  77     }
  78   else
  79     {
  80       SCM pos = elt_l_->get_elt_property ("staff-position");
  81       if (gh_number_p (pos))
  82         return gh_scm2double (pos);
  83     }
  84
  85   return  p;
  86 }
  87
  88
  89
  90 /*
  91   should use offset callback!
  92  */
  93 Real
  94 Staff_symbol_referencer_interface::callback (Score_element const* sc,Axis )
  95 {
  96   Score_element* me = (Score_element*)sc; // UGH.
  97
  98   SCM pos = sc->get_elt_property ("staff-position");
  99   Real off =0.0;
 100   if (gh_number_p (pos))
 101     {
 102       Real space = staff_symbol_referencer (sc).staff_space ();
 103       off = gh_scm2double (pos) * space/2.0;
 104     }
 105
 106   me->set_elt_property ("staff-position", gh_double2scm (0.0));
 107
 108   return off;
 109 }
 110
 111 /*
 112
 113   This sets the position relative to the center of the staff symbol.
 114
 115   The function is hairy, because it can be callled in two situations:
 116
 117   1.  There is no staff yet; we must set staff-position
 118
 119   2.  There is a staff, and perhaps someone even applied a
 120   translate_axis (). Then we must compensate for the translation
 121
 122   In either case, we set a callback to be sure that our new position
 123   will be extracted from staff-position
 124
 125  */
 126 void
 127 Staff_symbol_referencer_interface::set_position (Real p)
 128 {
 129   Staff_symbol * st = staff_symbol_l ();
 130   if (st && elt_l_->common_refpoint(st, Y_AXIS))
 131     {
 132       Real oldpos = position_f ();
 133       elt_l_->set_elt_property ("staff-position", gh_double2scm (p - oldpos));
 134     }
 135   else
 136     {
 137       elt_l_->set_elt_property ("staff-position",
 138                                 gh_double2scm (p));
 139
 140     }
 141
 142   if (elt_l_->has_offset_callback_b (callback, Y_AXIS))
 143     return ;
 144
 145   elt_l_->add_offset_callback (callback, Y_AXIS);
 146 }
 147
 148 Staff_symbol_referencer_interface
 149 staff_symbol_referencer (Score_element const*e)
 150 {
 151   return e;                     // gee, I'm so smart!
 152 }
 153
 154 int
 155 compare_position (Score_element *const  &a, Score_element * const &b)
 156 {
 157   Staff_symbol_referencer_interface s1(a);
 158   Staff_symbol_referencer_interface s2(b);
 159
 160   return sign(s1.position_f () - s2.position_f ());
 161 }