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--2001 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
  15 bool
  16 Staff_symbol_referencer::has_interface (Grob*e)
  17 {
  18   return unsmob_grob (e->get_grob_property ("staff-symbol"))
  19     || gh_number_p (e->get_grob_property ("staff-position"));
  20 }
  21
  22 int
  23 Staff_symbol_referencer::line_count (Grob*me)
  24 {
  25   Grob *st = staff_symbol_l (me);
  26   return st  ?  Staff_symbol::line_count (st) : 0;
  27 }
  28
  29 bool
  30 Staff_symbol_referencer::on_staffline (Grob*me)
  31 {
  32   return on_staffline (me, (int) rint (position_f (me)));
  33 }
  34
  35 bool
  36 Staff_symbol_referencer::on_staffline (Grob*me, int pos)
  37 {
  38   int sz = line_count (me)-1;
  39   return ((pos + sz) % 2) == 0;
  40 }
  41
  42 Grob*
  43 Staff_symbol_referencer::staff_symbol_l (Grob*me)
  44 {
  45   SCM st = me->get_grob_property ("staff-symbol");
  46   return unsmob_grob (st);
  47 }
  48
  49 Real
  50 Staff_symbol_referencer::staff_space (Grob*me)
  51 {
  52   Grob * st = staff_symbol_l (me);
  53   if (st)
  54     return Staff_symbol::staff_space (st);
  55
  56
  57   return 1.0;
  58 }
  59
  60
  61 Real
  62 Staff_symbol_referencer::position_f (Grob*me)
  63 {
  64   Real p =0.0;
  65   Grob * st = staff_symbol_l (me);
  66   Grob * c = st ? me->common_refpoint (st, Y_AXIS) : 0;
  67   if (st && c)
  68     {
  69       Real y = me->relative_coordinate (c, Y_AXIS)
  70         - st->relative_coordinate (c, Y_AXIS);
  71
  72       p += 2.0 * y / Staff_symbol::staff_space (st);
  73     }
  74   else
  75     {
  76       SCM pos = me->get_grob_property ("staff-position");
  77       if (gh_number_p (pos))
  78         return gh_scm2double (pos);
  79     }
  80
  81   return  p;
  82 }
  83
  84
  85
  86 /*
  87   should use offset callback!
  88  */
  89 MAKE_SCHEME_CALLBACK (Staff_symbol_referencer,callback,2);
  90 SCM
  91 Staff_symbol_referencer::callback (SCM element_smob, SCM)
  92 {
  93   Grob *me = unsmob_grob (element_smob);
  94
  95
  96   SCM pos = me->get_grob_property ("staff-position");
  97   Real off =0.0;
  98   if (gh_number_p (pos))
  99     {
 100       Real space = Staff_symbol_referencer::staff_space (me);
 101       off = gh_scm2double (pos) * space/2.0;
 102     }
 103
 104   me->set_grob_property ("staff-position", gh_double2scm (0.0));
 105
 106   return gh_double2scm (off);
 107 }
 108
 109  /*
 110
 111   This sets the position relative to the center of the staff symbol.
 112
 113   The function is hairy, because it can be callled in two situations:
 114
 115   1.  There is no staff yet; we must set staff-position
 116
 117   2.  There is a staff, and perhaps someone even applied a
 118   translate_axis (). Then we must compensate for the translation
 119
 120   In either case, we set a callback to be sure that our new position
 121   will be extracted from staff-position
 122
 123  */
 124 void
 125 Staff_symbol_referencer::set_position (Grob*me,Real p)
 126 {
 127   Grob * st = staff_symbol_l (me);
 128   if (st && me->common_refpoint (st, Y_AXIS))
 129     {
 130       Real oldpos = position_f (me);
 131       me->set_grob_property ("staff-position", gh_double2scm (p - oldpos));
 132     }
 133   else
 134     {
 135       me->set_grob_property ("staff-position",
 136                             gh_double2scm (p));
 137
 138     }
 139
 140   if (me->has_offset_callback_b (Staff_symbol_referencer::callback_proc, Y_AXIS))
 141     return ;
 142
 143   me->add_offset_callback (Staff_symbol_referencer::callback_proc, Y_AXIS);
 144 }
 145
 146 /*
 147   half  of the height, in staff space.
 148  */
 149 Real
 150 Staff_symbol_referencer::staff_radius (Grob*me)
 151 {
 152   return (line_count (me) -1) / 2;
 153 }
 154
 155
 156 int
 157 compare_position (Grob *const  &a, Grob * const &b)
 158 {
 159   return sign (Staff_symbol_referencer::position_f ((Grob*)a) -
 160     Staff_symbol_referencer::position_f ((Grob*)b));
 161 }
 162
 163
 164 void
 165 Staff_symbol_referencer::set_interface (Grob * e)
 166 {
 167   if (!gh_number_p (e->get_grob_property ("staff-position")))
 168       e->set_grob_property ("staff-position", gh_double2scm (0.0));
 169
 170   e->add_offset_callback (Staff_symbol_referencer::callback_proc, Y_AXIS);
 171 }
 172