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--2003 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 /* Limitations/Bugs:
  31
  32    (1) Elements from 'me->get_grob_property ("elements")' must be
  33    ordered according to their y coordinates relative to their common
  34    axis group parent.  Otherwise, the computation goes mad.
  35
  36    (TODO:
  37    apply a sort algorithm that ensures this precondition.)  However,
  38    until now, I have seen no case where lily has not fulfilled this
  39    precondition.
  40
  41    (2) This method depends on bar_engraver not being removed from
  42    staff context.  If bar_engraver is removed, the size of the staff
  43    lines is evaluated as 0, which results in a solid span bar line
  44    with faulty y coordinate. */
  45
  46 /* This routine was originally by Juergen Reuter, but it was a on the
  47    bulky side. Rewritten by Han-Wen. */
  48 SCM
  49 Span_bar::brew_molecule (SCM smobbed_me)
  50 {
  51   Grob *me = unsmob_grob (smobbed_me);
  52   SCM first_elt = me->get_grob_property ("elements");
  53
  54   /* compute common refpoint of elements */
  55   Grob *refp = me;
  56   for (SCM elts = first_elt; gh_pair_p (elts); elts = ly_cdr (elts))
  57     {
  58       SCM smobbed_staff_bar = ly_car (elts);
  59       Grob *staff_bar = unsmob_grob (smobbed_staff_bar);
  60       refp = staff_bar->common_refpoint (refp, Y_AXIS);
  61     }
  62
  63   Span_bar::evaluate_glyph (me);
  64   SCM glyph = me->get_grob_property ("glyph");
  65
  66   /* glyph may not be a string, when ME is killed by Hara Kiri in
  67     between. */
  68   if (!gh_string_p (glyph))
  69     return SCM_EOL;
  70
  71   String glyph_string = ly_scm2string (glyph);
  72
  73   /* compose span_bar_mol */
  74   Molecule span_bar_mol;
  75
  76   Interval prev_extent;
  77   for (SCM elts = first_elt; gh_pair_p (elts); elts = ly_cdr (elts))
  78     {
  79       SCM smobbed_staff_bar = ly_car (elts);
  80       Grob *staff_bar = unsmob_grob (smobbed_staff_bar);
  81       Interval ext = staff_bar->extent (refp, Y_AXIS);
  82       if (ext.empty_b ())
  83         continue;
  84
  85       if (!prev_extent.empty_b ())
  86         {
  87           Interval l (prev_extent [UP],
  88                      ext[DOWN]);
  89
  90           if (l.empty_b ())
  91             {
  92               /* There is overlap between the bar lines.  Do nothing. */
  93             }
  94           else
  95             {
  96               Molecule interbar = Bar_line::compound_barline (staff_bar,
  97                                                               glyph_string,
  98                                                               l.length ());
  99               interbar.translate_axis (l.center (), Y_AXIS);
 100               span_bar_mol.add_molecule (interbar);
 101             }
 102         }
 103       prev_extent = ext;
 104     }
 105
 106   span_bar_mol.translate_axis (- me->relative_coordinate (refp, Y_AXIS),
 107                                Y_AXIS);
 108
 109   return span_bar_mol.smobbed_copy ();
 110 }
 111
 112 MAKE_SCHEME_CALLBACK (Span_bar,width_callback,2);
 113 SCM
 114 Span_bar::width_callback (SCM element_smob, SCM scm_axis)
 115 {
 116   Grob *se = unsmob_grob (element_smob);
 117   Axis a = (Axis) gh_scm2int (scm_axis);
 118   assert (a == X_AXIS);
 119   String gl = ly_scm2string (se->get_grob_property ("glyph"));
 120
 121   /*
 122     urg.
 123   */
 124   Molecule m = Bar_line::compound_barline (se, gl, 40 PT);
 125
 126   return ly_interval2scm (m.extent (X_AXIS));
 127 }
 128
 129 MAKE_SCHEME_CALLBACK (Span_bar,before_line_breaking,1);
 130 SCM
 131 Span_bar::before_line_breaking (SCM smob)
 132 {
 133   evaluate_empty (unsmob_grob (smob));
 134   evaluate_glyph (unsmob_grob (smob));
 135
 136   /* No need to call Bar_line::before_line_breaking (), because the info
 137      in ELEMENTS already has been procced by
 138      Bar_line::before_line_breaking (). */
 139   return SCM_UNSPECIFIED;
 140 }
 141
 142 MAKE_SCHEME_CALLBACK (Span_bar,center_on_spanned_callback,2);
 143
 144 SCM
 145 Span_bar::center_on_spanned_callback (SCM element_smob, SCM axis)
 146 {
 147   Grob *me = unsmob_grob (element_smob);
 148   Axis a = (Axis) gh_scm2int (axis);
 149   assert (a == Y_AXIS);
 150   Interval i (get_spanned_interval (me));
 151
 152   /* Bar_line::brew_molecule delivers a barline of y-extent (-h/2,h/2), so
 153      we have to translate ourselves to be in the center of the
 154      interval that we span. */
 155   if (i.empty_b ())
 156     {
 157       me->suicide ();
 158       return gh_double2scm (0.0);
 159     }
 160
 161   return gh_double2scm (i.center ());
 162 }
 163
 164 void
 165 Span_bar::evaluate_empty (Grob*me)
 166 {
 167   /* TODO: filter all hara-kiried out of ELEMENS list, and then
 168      optionally do suicide. Call this cleanage function from
 169      center_on_spanned_callback () as well. */
 170   if (!gh_pair_p (me->get_grob_property ("elements")))
 171     {
 172       me->suicide ();
 173     }
 174 }
 175
 176 void
 177 Span_bar::evaluate_glyph (Grob*me)
 178 {
 179   SCM elts = me->get_grob_property ("elements");
 180   SCM glyph_symbol = ly_symbol2scm ("glyph");
 181   SCM gl = SCM_EOL;
 182
 183   while (gh_pair_p (elts))
 184     {
 185       gl = unsmob_grob (gh_car (elts))
 186         ->internal_get_grob_property (glyph_symbol);
 187       if (gh_string_p (gl))
 188         break;
 189       elts =gh_cdr (elts);
 190     }
 191
 192   if (!gh_string_p (gl))
 193     {
 194       me->suicide ();
 195       return;
 196     }
 197
 198   String type = ly_scm2string (gl);
 199   if (type == "|:")
 200     {
 201       type = ".|";
 202     }
 203   else if (type== ":|")
 204     {
 205       type = "|.";
 206     }
 207   else if (type== ":|:")
 208     {
 209       type = ".|.";
 210     }
 211
 212   gl = scm_makfrom0str (type.to_str0 ());
 213   if (scm_equal_p (me->internal_get_grob_property (glyph_symbol), gl)
 214       != SCM_BOOL_T)
 215     me->internal_set_grob_property (glyph_symbol, gl);
 216 }
 217
 218 Interval
 219 Span_bar::get_spanned_interval (Grob*me)
 220 {
 221   return ly_scm2interval (Axis_group_interface::group_extent_callback
 222                           (me->self_scm (), gh_int2scm (Y_AXIS)));
 223 }
 224
 225
 226 MAKE_SCHEME_CALLBACK (Span_bar,get_bar_size,1);
 227 SCM
 228 Span_bar::get_bar_size (SCM smob)
 229 {
 230   Grob* me =  unsmob_grob (smob);
 231   Interval iv (get_spanned_interval (me));
 232   if (iv.empty_b ())
 233     {
 234       /* This happens if the bars are hara-kiried from under us. */
 235       me->suicide ();
 236       return gh_double2scm (-1);
 237     }
 238   return gh_double2scm (iv.length ());
 239 }
 240
 241
 242
 243 ADD_INTERFACE (Span_bar,"span-bar-interface",
 244   "A bar line that spans other barlines (typically used to get cross-staff barlines.",
 245   "");
 246
 247