lily/align-interface.cc

   1 /*
   2   align-interface.cc -- implement Align_interface
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2000--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "align-interface.hh"
  10 #include "spanner.hh"
  11 #include "item.hh"
  12 #include "axis-group-interface.hh"
  13 #include "pointer-group-interface.hh"
  14 #include "hara-kiri-group-spanner.hh"
  15 #include "grob-array.hh"
  16 #include "international.hh"
  17 #include "system.hh"
  18 #include "warn.hh"
  19 #include "paper-column.hh"
  20
  21 /*
  22   TODO: for vertical spacing, should also include a rod & spring
  23   scheme of sorts into this: the alignment should default to a certain
  24   distance between element refpoints, unless bbox force a bigger
  25   distance.
  26  */
  27
  28 MAKE_SCHEME_CALLBACK (Align_interface, calc_positioning_done, 1);
  29 SCM
  30 Align_interface::calc_positioning_done (SCM smob)
  31 {
  32   Grob *me = unsmob_grob (smob);
  33
  34   me->set_property ("positioning-done", SCM_BOOL_T);
  35
  36   SCM axis = scm_car (me->get_property ("axes"));
  37   Axis ax = Axis (scm_to_int (axis));
  38
  39   Align_interface::align_elements_to_extents (me, ax);
  40
  41   return SCM_BOOL_T;
  42 }
  43
  44 /*
  45   TODO: This belongs to the old two-pass spacing. Delete me.
  46 */
  47 MAKE_SCHEME_CALLBACK (Align_interface, stretch_after_break, 1)
  48 SCM
  49 Align_interface::stretch_after_break (SCM grob)
  50 {
  51   Grob *me = unsmob_grob (grob);
  52
  53   Spanner *me_spanner = dynamic_cast<Spanner *> (me);
  54   extract_grob_set (me, "elements", elems);
  55
  56   if (me_spanner && elems.size ())
  57     {
  58       Grob *common = common_refpoint_of_array (elems, me, Y_AXIS);
  59
  60       /* force position callbacks */
  61       for (vsize i = 0; i < elems.size (); i++)
  62         elems[i]->relative_coordinate (common, Y_AXIS);
  63
  64       SCM details = me_spanner->get_bound (LEFT)->get_property ("line-break-system-details");
  65       SCM extra_space_handle = scm_assoc (ly_symbol2scm ("fixed-alignment-extra-space"), details);
  66
  67       Real extra_space = robust_scm2double (scm_is_pair (extra_space_handle)
  68                                             ? scm_cdr (extra_space_handle)
  69                                             : SCM_EOL,
  70                                             0.0);
  71
  72       Direction stacking_dir = robust_scm2dir (me->get_property ("stacking-dir"),
  73                                                DOWN);
  74       Real delta  = extra_space / elems.size () * stacking_dir;
  75       for (vsize i = 0; i < elems.size (); i++)
  76         elems[i]->translate_axis (i * delta, Y_AXIS);
  77     }
  78
  79   return SCM_UNSPECIFIED;
  80 }
  81
  82 /* for each grob, find its upper and lower skylines. If the grob has
  83    an empty extent, delete it from the list instead. If the extent is
  84    non-empty but there is no skyline available (or pure is true), just
  85    create a flat skyline from the bounding box */
  86 static void
  87 get_skylines (Grob *me,
  88               vector<Grob*> *const elements,
  89               Axis a,
  90               bool pure, int start, int end,
  91               vector<Skyline_pair> *const ret)
  92 {
  93   /* each child's skyline was calculated according to the common refpoint of its
  94      elements. Here we need all the skylines to be positioned with respect to
  95      a single refpoint, so we need the common refpoint of the common refpoints
  96      of the elements of the children */
  97   vector<Grob*> child_refpoints;
  98   for (vsize i = 0; i < elements->size (); i++)
  99     {
 100       Grob *elt = (*elements)[i];
 101       Grob *child_common = unsmob_grob ((a == Y_AXIS)
 102                                         ? elt->get_object ("X-common")
 103                                         : elt->get_object ("Y-common"));
 104
 105       if (!child_common)
 106         {
 107           extract_grob_set (elt, "elements", child_elts);
 108           child_common = common_refpoint_of_array (child_elts, elt, other_axis (a));
 109         }
 110
 111       child_refpoints.push_back (child_common);
 112     }
 113
 114   Grob *other_common = common_refpoint_of_array (child_refpoints, me, other_axis (a));
 115
 116   for (vsize i = elements->size (); i--;)
 117     {
 118       Grob *g = (*elements)[i];
 119       Skyline_pair skylines;
 120
 121       /* each skyline is calculated relative to (potentially) a different other_axis
 122          coordinate. In order to compare the skylines effectively, we need to shift them
 123          to some absolute reference point */
 124       if (!pure)
 125         {
 126           Skyline_pair *skys = Skyline_pair::unsmob (g->get_property (a == Y_AXIS
 127                                                                       ? "vertical-skylines"
 128                                                                       : "horizontal-skylines"));
 129           if (skys)
 130             skylines = *skys;
 131
 132           /* this is perhaps an abuse of minimum-?-extent: maybe we should create
 133              another property? But it seems that the only (current) use of
 134              minimum-Y-extent is to separate vertically-aligned elements */
 135           SCM min_extent = g->get_property (a == X_AXIS
 136                                             ? ly_symbol2scm ("minimum-X-extent")
 137                                             : ly_symbol2scm ("minimum-Y-extent"));
 138
 139           if (is_number_pair (min_extent))
 140             {
 141               Box b;
 142               Interval other_extent = g->extent (other_common, other_axis (a));
 143               b[a] = ly_scm2interval (min_extent);
 144               b[other_axis (a)] = other_extent;
 145               if (!other_extent.is_empty ())
 146                 skylines.insert (b, 0, other_axis (a));
 147             }
 148
 149           Real offset = child_refpoints[i]->relative_coordinate (other_common, other_axis (a));
 150           skylines.shift (offset);
 151         }
 152       else
 153         {
 154           assert (a == Y_AXIS);
 155           Interval extent = g->pure_height (g, start, end);
 156           if (!extent.is_empty ())
 157             {
 158               Box b;
 159               b[a] = extent;
 160               b[other_axis (a)] = Interval (-infinity_f, infinity_f);
 161               skylines.insert (b, 0, other_axis (a));
 162             }
 163         }
 164
 165       if (skylines.is_empty ())
 166         elements->erase (elements->begin () + i);
 167       else
 168         ret->push_back (skylines);
 169     }
 170   reverse (*ret);
 171 }
 172
 173 vector<Real>
 174 Align_interface::get_extents_aligned_translates (Grob *me,
 175                                                  vector<Grob*> const &all_grobs,
 176                                                  Axis a,
 177                                                  bool pure, int start, int end)
 178 {
 179   Spanner *me_spanner = dynamic_cast<Spanner *> (me);
 180
 181
 182   SCM line_break_details = SCM_EOL;
 183   if (a == Y_AXIS && me_spanner)
 184     {
 185       if (pure)
 186         line_break_details = get_root_system (me)->column (start)->get_property ("line-break-system-details");
 187       else
 188         line_break_details = me_spanner->get_bound (LEFT)->get_property ("line-break-system-details");
 189
 190       if (!me->get_system () && !pure)
 191         me->programming_error ("vertical alignment called before line-breaking");
 192     }
 193
 194   Direction stacking_dir = robust_scm2dir (me->get_property ("stacking-dir"),
 195                                            DOWN);
 196
 197   vector<Grob*> elems (all_grobs); // writable copy
 198   vector<Skyline_pair> skylines;
 199
 200   get_skylines (me, &elems, a, pure, start, end, &skylines);
 201
 202   Real where = 0;
 203   /* TODO: extra-space stuff belongs to two-pass spacing. Delete me */
 204   SCM extra_space_handle = scm_assq (ly_symbol2scm ("alignment-extra-space"), line_break_details);
 205   Real extra_space = robust_scm2double (scm_is_pair (extra_space_handle)
 206                                         ? scm_cdr (extra_space_handle)
 207                                         : SCM_EOL,
 208                                         0.0);
 209
 210   Real padding = robust_scm2double (me->get_property ("padding"), 0.0);
 211   vector<Real> translates;
 212   Skyline down_skyline (stacking_dir);
 213   for (vsize j = 0; j < elems.size (); j++)
 214     {
 215       Real dy = 0;
 216       if (j == 0)
 217         dy = skylines[j][-stacking_dir].max_height ();
 218       else
 219         {
 220           down_skyline.merge (skylines[j-1][stacking_dir]);
 221           dy = down_skyline.distance (skylines[j][-stacking_dir]);
 222         }
 223
 224       if (isinf (dy)) /* if the skyline is empty, maybe max_height is infinity_f */
 225         dy = 0.0;
 226
 227       dy = max (0.0, dy + padding + extra_space / elems.size ());
 228       down_skyline.raise (-stacking_dir * dy);
 229       where += stacking_dir * dy;
 230       translates.push_back (where);
 231     }
 232
 233   SCM offsets_handle = scm_assq (ly_symbol2scm ("alignment-offsets"),
 234                                  line_break_details);
 235   if (scm_is_pair (offsets_handle))
 236     {
 237       vsize i = 0;
 238
 239       for (SCM s = scm_cdr (offsets_handle);
 240            scm_is_pair (s) && i < translates.size (); s = scm_cdr (s), i++)
 241         {
 242           if (scm_is_number (scm_car (s)))
 243             translates[i] = scm_to_double (scm_car (s));
 244         }
 245     }
 246
 247   vector<Real> all_translates;
 248
 249   if (!translates.empty ())
 250     {
 251       Real w = translates[0];
 252       for  (vsize i = 0, j = 0; j < all_grobs.size (); j++)
 253         {
 254           if (i < elems.size () && all_grobs[j] == elems[i])
 255             w = translates[i++];
 256           all_translates.push_back (w);
 257         }
 258     }
 259   return all_translates;
 260 }
 261
 262 void
 263 Align_interface::align_elements_to_extents (Grob *me, Axis a)
 264 {
 265   extract_grob_set (me, "elements", all_grobs);
 266
 267   vector<Real> translates = get_extents_aligned_translates (me, all_grobs, a, false, 0, 0);
 268   if (translates.size ())
 269     for (vsize j = 0; j < all_grobs.size (); j++)
 270       all_grobs[j]->translate_axis (translates[j], a);
 271 }
 272
 273 /* After we have already determined the y-offsets of our children, we may still
 274    want to stretch them a little. */
 275 void
 276 Align_interface::stretch (Grob *me, Real amount, Axis a)
 277 {
 278   extract_grob_set (me, "elements", elts);
 279   Real non_empty_elts = stretchable_children_count (me);
 280   Real offset = 0.0;
 281   Direction dir = robust_scm2dir (me->get_property ("stacking-dir"), DOWN);
 282   for (vsize i = 1; i < elts.size (); i++)
 283     {
 284       if (!elts[i]->extent (me, a).is_empty ()
 285           && !to_boolean (elts[i]->get_property ("keep-fixed-while-stretching")))
 286         offset += amount / non_empty_elts;
 287       elts[i]->translate_axis (dir * offset, a);
 288     }
 289   me->flush_extent_cache (Y_AXIS);
 290 }
 291
 292 Real
 293 Align_interface::get_pure_child_y_translation (Grob *me, Grob *ch, int start, int end)
 294 {
 295   extract_grob_set (me, "elements", all_grobs);
 296   SCM dy_scm = me->get_property ("forced-distance");
 297
 298   if (scm_is_number (dy_scm))
 299     {
 300       Real dy = scm_to_double (dy_scm) * robust_scm2dir (me->get_property ("stacking-dir"), DOWN);
 301       Real pos = 0;
 302       for (vsize i = 0; i < all_grobs.size (); i++)
 303         {
 304           if (all_grobs[i] == ch)
 305             return pos;
 306           if (!Hara_kiri_group_spanner::has_interface (all_grobs[i])
 307               || !Hara_kiri_group_spanner::request_suicide (all_grobs[i], start, end))
 308             pos += dy;
 309         }
 310     }
 311   else
 312     {
 313       vector<Real> translates = get_extents_aligned_translates (me, all_grobs, Y_AXIS, true, start, end);
 314
 315       if (translates.size ())
 316         {
 317           for (vsize i = 0; i < all_grobs.size (); i++)
 318             if (all_grobs[i] == ch)
 319               return translates[i];
 320         }
 321       else
 322         return 0;
 323     }
 324
 325   programming_error (_ ("tried to get a translation for something that is no child of mine"));
 326   return 0;
 327 }
 328
 329 Axis
 330 Align_interface::axis (Grob *me)
 331 {
 332   return Axis (scm_to_int (scm_car (me->get_property ("axes"))));
 333 }
 334
 335 void
 336 Align_interface::add_element (Grob *me, Grob *element)
 337 {
 338   Axis a = Align_interface::axis (me);
 339   SCM sym = axis_offset_symbol (a);
 340   SCM proc = axis_parent_positioning (a);
 341
 342   element->set_property (sym, proc);
 343   Axis_group_interface::add_element (me, element);
 344 }
 345
 346 void
 347 Align_interface::set_ordered (Grob *me)
 348 {
 349   SCM ga_scm = me->get_object ("elements");
 350   Grob_array *ga = unsmob_grob_array (ga_scm);
 351   if (!ga)
 352     {
 353       ga_scm = Grob_array::make_array ();
 354       ga = unsmob_grob_array (ga_scm);
 355       me->set_object ("elements", ga_scm);
 356     }
 357
 358   ga->set_ordered (true);
 359 }
 360
 361 int
 362 Align_interface::stretchable_children_count (Grob const *me)
 363 {
 364   extract_grob_set (me, "elements", elts);
 365   int ret = 0;
 366
 367   /* start at 1: we will never move the first child while stretching */
 368   for (vsize i = 1; i < elts.size (); i++)
 369     if (!to_boolean (elts[i]->get_property ("keep-fixed-while-stretching"))
 370         && !elts[i]->extent (elts[i], Y_AXIS).is_empty ())
 371       ret++;
 372
 373   return ret;
 374 }
 375
 376 MAKE_SCHEME_CALLBACK (Align_interface, calc_max_stretch, 1)
 377 SCM
 378 Align_interface::calc_max_stretch (SCM smob)
 379 {
 380   Grob *me = unsmob_grob (smob);
 381   Spanner *spanner_me = dynamic_cast<Spanner*> (me);
 382   Real ret = 0;
 383
 384   if (spanner_me && stretchable_children_count (me) > 0)
 385     {
 386       Paper_column *left = dynamic_cast<Paper_column*> (spanner_me->get_bound (LEFT));
 387       Real height = me->extent (me, Y_AXIS).length ();
 388       SCM line_break_details = left->get_property ("line-break-system-details");
 389       SCM fixed_offsets = scm_assq (ly_symbol2scm ("alignment-offsets"),
 390                                     line_break_details);
 391
 392       /* if there are fixed offsets, we refuse to stretch */
 393       if (fixed_offsets != SCM_BOOL_F)
 394         ret = 0;
 395       else
 396         ret = height * height / 80.0; /* why this, exactly? -- jneem */
 397     }
 398   return scm_from_double (ret);
 399 }
 400
 401 ADD_INTERFACE (Align_interface,
 402
 403                "Order grobs from top to bottom, left to right, right to left or bottom "
 404                "to top.  "
 405                "For vertical alignments of staves, the @code{break-system-details} of "
 406                "the left @internalsref{NonMusicalPaperColumn} may be set to tune vertical spacing "
 407                "Set @code{alignment-extra-space} to add extra space for staves. Set "
 408                "@code{fixed-alignment-extra-space} to force staves in PianoStaves further apart."
 409                ,
 410
 411                /*
 412                  properties
 413                 */
 414                "align-dir "
 415                "axes "
 416                "elements "
 417                "padding "
 418                "positioning-done "
 419                "stacking-dir "
 420                "threshold "
 421                );