lily/span-bar.cc

   1 /*
   2   span-bar.cc -- implement Span_bar
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c)  1997--2002 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8
   9 #include "span-bar.hh"
  10 #include "font-interface.hh"
  11 #include "dimensions.hh"
  12 #include "paper-def.hh"
  13 #include "molecule.hh"
  14 #include "warn.hh"
  15 #include "axis-group-interface.hh"
  16 #include "group-interface.hh"
  17 #include "grob.hh"
  18 #include "bar-line.hh"
  19
  20 void
  21 Span_bar::add_bar (Grob*me, Grob*b)
  22 {
  23   Pointer_group_interface::add_grob (me, ly_symbol2scm ("elements"),  b);
  24
  25   me->add_dependency (b);
  26 }
  27
  28 MAKE_SCHEME_CALLBACK (Span_bar,brew_molecule,1);
  29
  30 /*
  31   Limitations/Bugs:
  32
  33    (1) Elements from 'me->get_grob_property ("elements")' must be
  34    ordered according to their y coordinates relative to their common
  35    axis group parent.  Otherwise, the computation goes mad.
  36
  37    (TODO:
  38    apply a sort algorithm that ensures this precondition.)  However,
  39    until now, I have seen no case where lily has not fulfilled this
  40    precondition.
  41
  42    (2) This method depends on bar_engraver not being removed from
  43    staff context.  If bar_engraver is removed, the size of the staff
  44    lines is evaluated as 0, which results in a solid span bar line
  45    with faulty y coordinate.
  46  */
  47
  48 /*
  49   This routine was originally by Juergen Reuter, but it was a on the
  50   bulky side. Rewritten by Han-Wen.
  51  */
  52 SCM
  53 Span_bar::brew_molecule (SCM smobbed_me)
  54 {
  55   Grob *me = unsmob_grob (smobbed_me);
  56   SCM first_elt = me->get_grob_property ("elements");
  57
  58   // compute common refpoint of elements
  59   Grob *refp = me;
  60   for (SCM elts = first_elt; gh_pair_p (elts); elts = ly_cdr (elts))
  61     {
  62       SCM smobbed_staff_bar = ly_car (elts);
  63       Grob *staff_bar = unsmob_grob (smobbed_staff_bar);
  64       refp = staff_bar->common_refpoint (refp, Y_AXIS);
  65     }
  66
  67   Span_bar::evaluate_glyph(me);
  68   SCM glyph = me->get_grob_property ("glyph");
  69
  70   /*
  71     glyph may not be a string, when ME is killed by Hara Kiri in
  72     between.
  73   */
  74   if (!gh_string_p (glyph))
  75     return SCM_EOL;
  76
  77   String glyph_string = ly_scm2string (glyph);
  78
  79   // compose span_bar_mol
  80   Molecule span_bar_mol;
  81
  82   Interval prev_extent;
  83   for (SCM elts = first_elt; gh_pair_p (elts); elts = ly_cdr (elts))
  84     {
  85       SCM smobbed_staff_bar = ly_car (elts);
  86       Grob *staff_bar = unsmob_grob (smobbed_staff_bar);
  87       Interval ext = staff_bar->extent (refp, Y_AXIS);
  88       if (ext.empty_b ())
  89         continue;
  90
  91       if (!prev_extent.empty_b ())
  92         {
  93           Interval l(prev_extent [UP],
  94                      ext[DOWN]);
  95
  96           if (l.empty_b ())
  97             {
  98               /* there is  overlap between the bar lines. We do nothign here.
  99                */
 100             }
 101           else
 102             {
 103               Molecule interbar
 104                 = Bar_line::compound_barline (staff_bar, glyph_string, l.length());
 105               interbar.translate_axis (l.center (), Y_AXIS);
 106               span_bar_mol.add_molecule (interbar);
 107             }
 108         }
 109       prev_extent = ext;
 110     }
 111
 112   span_bar_mol.translate_axis (- me->relative_coordinate (refp, Y_AXIS), Y_AXIS);
 113
 114   return span_bar_mol.smobbed_copy ();
 115 }
 116
 117 MAKE_SCHEME_CALLBACK (Span_bar,width_callback,2);
 118 SCM
 119 Span_bar::width_callback (SCM element_smob, SCM scm_axis)
 120 {
 121   Grob *se = unsmob_grob (element_smob);
 122   Axis a = (Axis) gh_scm2int (scm_axis);
 123   assert (a == X_AXIS);
 124   String gl = ly_scm2string (se->get_grob_property ("glyph"));
 125
 126   /*
 127     urg.
 128   */
 129   Molecule m = Bar_line::compound_barline (se, gl, 40 PT);
 130
 131   return ly_interval2scm (m.extent (X_AXIS));
 132 }
 133
 134 MAKE_SCHEME_CALLBACK (Span_bar,before_line_breaking,1);
 135 SCM
 136 Span_bar::before_line_breaking (SCM smob)
 137 {
 138   evaluate_empty (unsmob_grob (smob));
 139   evaluate_glyph (unsmob_grob (smob));
 140
 141   /*
 142     no need to call   Bar_line::before_line_breaking (), because the info
 143     in ELEMENTS already has been procced by Bar_line::before_line_breaking ().
 144   */
 145   return SCM_UNSPECIFIED;
 146 }
 147
 148 MAKE_SCHEME_CALLBACK (Span_bar,center_on_spanned_callback,2);
 149
 150 SCM
 151 Span_bar::center_on_spanned_callback (SCM element_smob, SCM axis)
 152 {
 153   Grob *me = unsmob_grob (element_smob);
 154   Axis a = (Axis) gh_scm2int (axis);
 155   assert (a == Y_AXIS);
 156   Interval i (get_spanned_interval (me));
 157
 158   /*
 159     Bar_line::brew_molecule delivers a barline of y-extent (-h/2,h/2), so
 160     we have to translate ourselves to be in the center of the
 161     interval that we span.  */
 162   if (i.empty_b ())
 163     {
 164       me->suicide ();
 165       return gh_double2scm (0.0);
 166     }
 167
 168   return gh_double2scm (i.center ());
 169 }
 170
 171 void
 172 Span_bar::evaluate_empty (Grob*me)
 173 {
 174   /*
 175     TODO: filter all hara-kiried out of ELEMENS list, and then
 176     optionally do suicide. Call this cleanage function from
 177     center_on_spanned_callback () as well.
 178
 179    */
 180   if (!gh_pair_p (me->get_grob_property ("elements")))
 181     {
 182       me->suicide ();
 183     }
 184 }
 185
 186 void
 187 Span_bar::evaluate_glyph (Grob*me)
 188 {
 189   SCM elts = me->get_grob_property ("elements");
 190   SCM glyph_symbol = ly_symbol2scm ("glyph");
 191   SCM gl = SCM_EOL;
 192
 193   while (gh_pair_p (elts))
 194     {
 195       gl =  unsmob_grob (gh_car (elts))->internal_get_grob_property (glyph_symbol);
 196       if (gh_string_p (gl))
 197         break;
 198       elts =gh_cdr (elts);
 199     }
 200
 201   if (!gh_string_p (gl))
 202     {
 203       me->suicide ();
 204       return;
 205     }
 206
 207   String type = ly_scm2string (gl);
 208   if (type == "|:")
 209     {
 210       type = ".|";
 211     }
 212   else if (type== ":|")
 213     {
 214       type = "|.";
 215     }
 216   else if (type== ":|:")
 217     {
 218       type = ".|.";
 219     }
 220
 221   gl = scm_makfrom0str (type.to_str0 ());
 222   if (scm_equal_p (me->internal_get_grob_property (glyph_symbol), gl) != SCM_BOOL_T)
 223     me->internal_set_grob_property (glyph_symbol, gl);
 224 }
 225
 226 Interval
 227 Span_bar::get_spanned_interval (Grob*me)
 228 {
 229   return ly_scm2interval (Axis_group_interface::group_extent_callback (me->self_scm (), gh_int2scm (Y_AXIS)));
 230 }
 231
 232
 233 MAKE_SCHEME_CALLBACK (Span_bar,get_bar_size,1);
 234 SCM
 235 Span_bar::get_bar_size (SCM smob)
 236 {
 237   Grob* me =  unsmob_grob (smob);
 238   Interval iv (get_spanned_interval (me));
 239   if (iv.empty_b ())
 240     {
 241       /*
 242         This happens if the bars are hara-kiried from under us.
 243       */
 244       me->suicide ();
 245       return gh_double2scm (-1);
 246     }
 247   return gh_double2scm (iv.length ());
 248 }
 249
 250
 251
 252 ADD_INTERFACE (Span_bar,"span-bar-interface",
 253   "A bar line that spans other barlines (typically used to get cross-staff barlines.",
 254   "");
 255
 256