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