lily/line-spanner.cc

   1 /*
   2   line-spanner.cc -- implement Line_spanner
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2000--2004 Jan Nieuwenhuizen <janneke@gnu.org>
   7 */
   8
   9 #include <math.h>
  10
  11 #include "stencil.hh"
  12 #include "item.hh"
  13 #include "spanner.hh"
  14 #include "line-spanner.hh"
  15 #include "paper-def.hh"
  16 #include "paper-column.hh"
  17 #include "staff-symbol-referencer.hh"
  18 #include "font-interface.hh"
  19 #include "warn.hh"
  20 #include "align-interface.hh"
  21 #include "lookup.hh"
  22 #include "line-interface.hh"
  23
  24 Stencil
  25 zigzag_stencil (Grob *me,
  26                  Offset from,
  27                  Offset to)
  28 {
  29   Offset dz = to -from;
  30   Real dx = dz[X_AXIS];
  31   Real dy = dz[Y_AXIS];
  32
  33   Real thick = Staff_symbol_referencer::line_thickness (me);
  34   thick *= robust_scm2double (me->get_property ("thickness"), 1.0); // todo: staff sym referencer?
  35
  36   Real staff_space = Staff_symbol_referencer::staff_space (me);
  37
  38   double w = robust_scm2double (me->get_property ("zigzag-width"), 1)*staff_space;
  39   double l = robust_scm2double ( me->get_property ("zigzag-length"), 1)* w;
  40   double h = l>w/2 ? sqrt (l*l-w*w/4) : 0;
  41
  42   SCM list = scm_list_n (ly_symbol2scm ("zigzag-line"),
  43                       gh_bool2scm (true),
  44                       gh_double2scm (w),
  45                       gh_double2scm (h),
  46                       gh_double2scm (thick),
  47                       gh_double2scm (dx),
  48                       gh_double2scm (dy),
  49                       SCM_UNDEFINED);
  50   Box b;
  51   b.add_point (Offset (0,0));
  52   b.add_point (dz);
  53   b[X_AXIS].widen (thick/2);
  54   b[Y_AXIS].widen (thick/2);
  55
  56   return Stencil (b, list);
  57 }
  58
  59 MAKE_SCHEME_CALLBACK (Line_spanner, after_line_breaking, 1);
  60 SCM
  61 Line_spanner::after_line_breaking (SCM  g)
  62 {
  63   Grob *me  = unsmob_grob (g);
  64   Spanner*sp = dynamic_cast<Spanner*> (me);
  65
  66   /*
  67     We remove the line at the start of the line.  For piano voice
  68     indicators, it makes no sense to have them at the start of the
  69     line.
  70
  71     I'm not sure what the official rules for glissandi are, but
  72     usually the 2nd note of the glissando is "exact", so when playing
  73     from the start of the line, there is no need to glide.
  74
  75     From a typographical p.o.v. this makes sense, since the amount of
  76     space left of a note at the start of a line is very small.
  77
  78     --hwn.
  79
  80    */
  81   if (sp->get_bound (LEFT)->break_status_dir ()
  82       && !sp->get_bound (RIGHT)->break_status_dir ())
  83     {
  84       /*
  85         Can't do suicide, since this mucks up finding the trend.
  86        */
  87       me->set_property ("print-function", SCM_EOL);
  88
  89     }
  90   return SCM_EOL;
  91 }
  92
  93
  94 Stencil
  95 Line_spanner::line_stencil (Grob *me,
  96                              Offset from,
  97                              Offset to)
  98 {
  99   Offset dz = to -from ;
 100   SCM type = me->get_property ("style");
 101   if (gh_symbol_p (type)
 102       && (type == ly_symbol2scm ("line")
 103           || type == ly_symbol2scm ("dashed-line")
 104           || type == ly_symbol2scm ("dotted-line")
 105           || type == ly_symbol2scm ("zigzag")
 106           || (type == ly_symbol2scm ("trill") && dz[Y_AXIS] != 0)))
 107     {
 108       return  (type == ly_symbol2scm ("zigzag"))
 109         ? zigzag_stencil (me, from, to)
 110         : Line_interface::line (me, from, to);
 111     }
 112   else if (gh_symbol_p (type)
 113            && type == ly_symbol2scm ("trill"))
 114     {
 115       SCM alist_chain = Font_interface::text_font_alist_chain (me);
 116       SCM style_alist = scm_list_n (gh_cons (ly_symbol2scm ("font-encoding"),
 117                                              ly_symbol2scm ("music")),
 118                                     SCM_UNDEFINED);
 119
 120       Font_metric *fm = select_font (me->get_paper (),
 121                                      gh_cons (style_alist,
 122                                               alist_chain));
 123       Stencil m = fm->find_by_name ("scripts-trill-element");
 124       Stencil mol;
 125
 126       do
 127         mol.add_at_edge (X_AXIS, RIGHT, m, 0,0);
 128       while (m.extent (X_AXIS).length ()
 129              && mol.extent (X_AXIS).length ()
 130              + m.extent (X_AXIS).length () < dz[X_AXIS]);
 131
 132       /*
 133         FIXME: should center element on x/y
 134        */
 135       mol.translate_axis (m.extent (X_AXIS).length () / 2, X_AXIS);
 136       mol.translate_axis (-(mol.extent (Y_AXIS)[DOWN]
 137                             + mol.extent (Y_AXIS).length ())/2, Y_AXIS);
 138
 139       mol.translate (from);
 140       return mol;
 141     }
 142   return Stencil ();
 143 }
 144
 145 /*
 146   Find a common Y parent, which --if found-- should be the
 147   fixed-distance alignment.
 148  */
 149 Grob *
 150 line_spanner_common_parent (Grob *me)
 151 {
 152   Grob * common = find_fixed_alignment_parent (me);
 153   if (!common)
 154     {
 155       common = Staff_symbol_referencer::get_staff_symbol (me);
 156       if (common)
 157         common = common->get_parent (Y_AXIS);
 158       else
 159         common = me->get_parent (Y_AXIS);
 160     }
 161
 162   return common;
 163 }
 164
 165 /*
 166   Warning: this thing is a cross-staff object, so it should have empty Y-dimensions.
 167
 168  (If not, you risk that this is called from the staff-alignment
 169   routine, via stencil_extent. At this point, the staves aren't
 170   separated yet, so it doesn't work cross-staff.
 171
 172 */
 173
 174
 175 MAKE_SCHEME_CALLBACK (Line_spanner, print, 1);
 176 SCM
 177 Line_spanner::print (SCM smob)
 178 {
 179   Spanner *me = dynamic_cast<Spanner*> (unsmob_grob (smob));
 180
 181   Drul_array<Item*>  bound (me->get_bound (LEFT),
 182                             me->get_bound (RIGHT));
 183
 184
 185   Real gap = robust_scm2double (me->get_property ("gap"), 0.0);
 186
 187   Offset ofxy (gap, 0); /*offset from start point to start of line*/
 188   Offset dxy ;
 189   Offset my_off;
 190   Offset his_off;
 191
 192
 193   if (bound[RIGHT]->break_status_dir ())
 194     {
 195       if (bound[LEFT]->break_status_dir ())
 196         {
 197           programming_error ("line-spanner with two broken ends. Farewell sweet world.");
 198
 199           me->suicide ();
 200           return SCM_EOL;
 201         }
 202
 203       /*
 204         This is hairy. For the normal case, we simply find common
 205         parents, and draw a line between the bounds. When two note
 206         heads are on different lines, there is no common parent
 207         anymore. We have to find the piano-staff object.
 208       */
 209
 210       int k = broken_spanner_index (me);
 211       Spanner *parent_sp = dynamic_cast<Spanner*> (me->original_);
 212       Spanner *next_sp  = parent_sp->broken_intos_ [k+1];
 213       Item *next_bound = next_sp->get_bound (RIGHT);
 214
 215       if (next_bound->break_status_dir ())
 216         {
 217           programming_error ("no note heads for the line spanner on next line?"
 218                              " Confused.");
 219           me->suicide ();
 220           return SCM_EOL;
 221         }
 222
 223       Grob *commonx = bound[LEFT]->common_refpoint (bound[RIGHT], X_AXIS);
 224       commonx = me->common_refpoint (commonx, X_AXIS);
 225
 226       Grob *next_common_y = line_spanner_common_parent (next_bound);
 227       Grob *this_common_y = line_spanner_common_parent (bound[LEFT]);
 228
 229       Grob *all_common_y = me->common_refpoint (this_common_y, Y_AXIS);
 230
 231       Interval next_ext  = next_bound->extent (next_common_y, Y_AXIS);
 232       Interval this_ext  = bound[LEFT]->extent (this_common_y, Y_AXIS);
 233
 234       Real yoff = this_common_y->relative_coordinate (all_common_y, Y_AXIS);
 235
 236       Offset p1 (bound[LEFT]->extent (commonx, X_AXIS)[RIGHT],
 237                  this_ext.center ()  + yoff);
 238       Offset p2 (bound[RIGHT]->extent (commonx, X_AXIS)[LEFT],
 239                  next_ext.center () + yoff);
 240
 241       Offset dz (p2 -p1);
 242       Real len = dz.length ();
 243
 244       Offset dir  = dz *(1/ len);
 245       dz = (dz.length () - 2*gap) *dir;
 246
 247
 248       Stencil l (line_stencil (me, Offset (0, 0), dz));
 249
 250       l.translate (dir * gap +  p1
 251                    - Offset (me->relative_coordinate (commonx, X_AXIS),
 252                              me->relative_coordinate (all_common_y, Y_AXIS)));
 253
 254       return l.smobbed_copy ();
 255     }
 256   else
 257     {
 258       Grob *common[] = { me, me };
 259       for (int a = X_AXIS;  a < NO_AXES; a++)
 260         {
 261           common[a] = me->common_refpoint (bound[RIGHT], Axis (a));
 262           common[a] = common[a]->common_refpoint (bound[LEFT], Axis (a));
 263         }
 264
 265       // distance from center to start of line
 266       Real off = gap + ((bound[LEFT]->extent (bound[LEFT], X_AXIS).length ()*3)/4);
 267
 268       for (int a = X_AXIS; a < NO_AXES; a++)
 269         {
 270           Axis ax = (Axis)a;
 271           dxy[ax] =
 272             + bound[RIGHT]->extent (common[X_AXIS], ax).center ()
 273             - bound[LEFT]->extent (common[X_AXIS], ax).center ();
 274
 275           my_off[ax] =me->relative_coordinate (common[a], ax);
 276           his_off[ax] = bound[LEFT]->relative_coordinate (common[a], ax);
 277
 278         }
 279
 280       ofxy = dxy * (off/dxy.length ());
 281       dxy -= 2*ofxy;
 282
 283       Stencil line = line_stencil (me, Offset (0,0),dxy);
 284
 285       line.translate_axis (bound[LEFT]->extent (bound[LEFT], X_AXIS).length ()/2, X_AXIS);
 286       line.translate (ofxy - my_off + his_off);
 287       return line.smobbed_copy ();
 288     }
 289 }
 290
 291
 292 ADD_INTERFACE (Line_spanner, "line-spanner-interface",
 293                "Generic line drawn between two objects, e.g. for use with glissandi.\n"
 294                "The property @code{style} can be @code{line}, "
 295                "@code{dashed-line}, @code{trill}, \n"
 296                "@code{dotted-line} or @code{zigzag}.\n"
 297                "\n"
 298                ,
 299                "gap zigzag-width zigzag-length thickness");
 300
 301