lily/lookup.cc

   1 /*
   2   lookup.cc -- implement simple Lookup methods.
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c)  1997--2003 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8   Jan Nieuwenhuizen <janneke@gnu.org>
   9
  10   TODO
  11       Glissando
  12 */
  13 #include <math.h>
  14 #include <ctype.h>
  15
  16 #include "warn.hh"
  17 #include "dimensions.hh"
  18 #include "bezier.hh"
  19 #include "string-convert.hh"
  20 #include "file-path.hh"
  21 #include "main.hh"
  22 #include "lily-guile.hh"
  23 #include "molecule.hh"
  24 #include "lookup.hh"
  25 #include "font-metric.hh"
  26 #include "interval.hh"
  27
  28 Molecule
  29 Lookup::dot (Offset p, Real radius)
  30 {
  31   SCM at = (scm_list_n (ly_symbol2scm ("dot"),
  32                         gh_double2scm (p[X_AXIS]),
  33                         gh_double2scm (p[Y_AXIS]),
  34                         gh_double2scm (radius),
  35                         SCM_UNDEFINED));
  36   Box box;
  37   box.add_point (p - Offset (radius, radius));
  38   box.add_point (p + Offset (radius, radius));
  39   return Molecule (box, at);
  40 }
  41
  42 Molecule
  43 Lookup::beam (Real slope, Real width, Real thick)
  44 {
  45   Real height = slope * width;
  46   Real min_y = (0 <? height) - thick/2;
  47   Real max_y = (0 >? height) + thick/2;
  48
  49
  50
  51   Box b (Interval (0, width),
  52          Interval (min_y, max_y));
  53
  54
  55   SCM at = scm_list_n (ly_symbol2scm ("beam"),
  56                     gh_double2scm (width),
  57                     gh_double2scm (slope),
  58                     gh_double2scm (thick),
  59                     SCM_UNDEFINED);
  60   return Molecule (b, at);
  61 }
  62
  63 Molecule
  64 Lookup::dashed_slur (Bezier b, Real thick, Real dash)
  65 {
  66   SCM l = SCM_EOL;
  67
  68   for (int i= 4; i -- ;)
  69     {
  70       l = gh_cons (ly_offset2scm (b.control_[i]), l);
  71     }
  72
  73   SCM at = (scm_list_n (ly_symbol2scm ("dashed-slur"),
  74                                gh_double2scm (thick),
  75                                gh_double2scm (dash),
  76                                ly_quote_scm (l),
  77                                SCM_UNDEFINED));
  78
  79   Box box (Interval (0,0),Interval (0,0));
  80   return   Molecule (box, at);
  81 }
  82
  83 Molecule
  84 Lookup::line (Real th, Offset f, Offset t)
  85 {
  86   SCM at = (scm_list_n (ly_symbol2scm ("draw-line"),
  87                         gh_double2scm (th),
  88                         gh_double2scm (f[X_AXIS]),
  89                         gh_double2scm (f[Y_AXIS]),
  90                         gh_double2scm (t[X_AXIS]),
  91                         gh_double2scm (t[Y_AXIS]),
  92                         SCM_UNDEFINED));
  93
  94   Box box;
  95   box.add_point (f);
  96   box.add_point (t);
  97
  98   box[X_AXIS].widen (th/2);
  99   box[Y_AXIS].widen (th/2);
 100
 101   return Molecule (box, at);
 102 }
 103
 104
 105 Molecule
 106 Lookup::blank (Box b)
 107 {
 108   return Molecule (b, scm_makfrom0str (""));
 109 }
 110
 111 Molecule
 112 Lookup::filledbox (Box b)
 113 {
 114   SCM  at  = (scm_list_n (ly_symbol2scm ("filledbox"),
 115                      gh_double2scm (-b[X_AXIS][LEFT]),
 116                      gh_double2scm (b[X_AXIS][RIGHT]),
 117                      gh_double2scm (-b[Y_AXIS][DOWN]),
 118                      gh_double2scm (b[Y_AXIS][UP]),
 119                      SCM_UNDEFINED));
 120
 121   return Molecule (b,at);
 122 }
 123
 124 /*
 125  * round filled box:
 126  *
 127  *   __________________________________
 128  *  /     \  ^           /     \      ^
 129  * |         |blot              |     |
 130  * |       | |dia       |       |     |
 131  * |         |meter             |     |
 132  * |\ _ _ /  v           \ _ _ /|     |
 133  * |                            |     |
 134  * |                            |     | Box
 135  * |                    <------>|     | extent
 136  * |                      blot  |     | (Y_AXIS)
 137  * |                    diameter|     |
 138  * |                            |     |
 139  * |  _ _                  _ _  |     |
 140  * |/     \              /     \|     |
 141  * |                            |     |
 142  * |       |            |       |     |
 143  * |                            |     |
 144  * x\_____/______________\_____/|_____v
 145  * |(0,0)                       |
 146  * |                            |
 147  * |                            |
 148  * |<-------------------------->|
 149  *       Box extent(X_AXIS)
 150  */
 151 Molecule
 152 Lookup::roundfilledbox (Box b, Real blotdiameter)
 153 {
 154   if (b.x ().length () < blotdiameter)
 155     {
 156       programming_error (_f ("round filled box horizontal extent smaller than blot; decreasing blot"));
 157       blotdiameter = b.x ().length ();
 158     }
 159   if (b.y ().length () < blotdiameter)
 160     {
 161       programming_error (_f ("round filled box vertical extent smaller than blot; decreasing blot"));
 162       blotdiameter = b.y ().length ();
 163     }
 164
 165   SCM at = (scm_list_n (ly_symbol2scm ("roundfilledbox"),
 166                         gh_double2scm (-b[X_AXIS][LEFT]),
 167                         gh_double2scm (b[X_AXIS][RIGHT]),
 168                         gh_double2scm (-b[Y_AXIS][DOWN]),
 169                         gh_double2scm (b[Y_AXIS][UP]),
 170                         gh_double2scm (blotdiameter),
 171                         SCM_UNDEFINED));
 172
 173   return Molecule (b,at);
 174 }
 175
 176 /*
 177  * Create Molecule that represents a filled polygon with round edges.
 178  *
 179  * LIMITATIONS:
 180  *
 181  * (a) Only outer (convex) edges are rounded.
 182  *
 183  * (b) This algorithm works as expected only for polygons whose edges
 184  * do not intersect.  For example, the polygon ((0, 0), (q, 0), (0,
 185  * q), (q, q)) has an intersection at point (q/2, q/2) and therefore
 186  * will give a strange result.  Even non-adjacent edges that just
 187  * touch each other will in general not work as expected for non-null
 188  * blotdiameter.
 189  *
 190  * (c) Given a polygon ((x0, y0), (x1, y1), ... , (x(n-1), y(n-1))),
 191  * if there is a natural number k such that blotdiameter is greater
 192  * than the maximum of { | (x(k mod n), y(k mod n)) - (x((k+1) mod n),
 193  * y((k+1) mod n)) |, | (x(k mod n), y(k mod n)) - (x((k+2) mod n),
 194  * y((k+2) mod n)) |, | (x((k+1) mod n), y((k+1) mod n)) - (x((k+2)
 195  * mod n), y((k+2) mod n)) | }, then the outline of the rounded
 196  * polygon will exceed the outline of the core polygon.  In other
 197  * words: Do not draw rounded polygons that have a leg smaller or
 198  * thinner than blotdiameter (or set blotdiameter to a sufficiently
 199  * small value -- maybe even 0.0)!
 200  *
 201  * NOTE: Limitations (b) and (c) arise from the fact that round edges
 202  * are made by moulding sharp edges to round ones rather than adding
 203  * to a core filled polygon.  For details of these two different
 204  * approaches, see the thread upon the ledger lines patch that started
 205  * on March 25, 2002 on the devel mailing list.  The below version of
 206  * round_filled_polygon() sticks to the moulding model, which the
 207  * majority of the list participants finally voted for.  This,
 208  * however, results in the above limitations and a much increased
 209  * complexity of the algorithm, since it has to compute a shrinked
 210  * polygon -- which is not trivial define precisely and unambigously.
 211  * With the other approach, one simply could move a circle of size
 212  * blotdiameter along all edges of the polygon (which is what the
 213  * postscript routine in the backend effectively does, but on the
 214  * shrinked polygon). --jr
 215  */
 216 Molecule
 217 Lookup::round_filled_polygon (Array<Offset> points, Real blotdiameter)
 218 {
 219   /* TODO: Maybe print a warning if one of the above limitations
 220      applies to the given polygon.  However, this is quite complicated
 221      to check. */
 222
 223   /* remove consecutive duplicate points */
 224   const Real epsilon = 0.01;
 225   for (int i = 0; i < points.size ();)
 226     {
 227       int next_i = (i + 1) % points.size ();
 228       Real d = (points[i] - points[next_i]).length ();
 229       if (d < epsilon)
 230         points.del (next_i);
 231       else
 232         i++;
 233     }
 234
 235   /* special cases: degenerated polygons */
 236   if (points.size () == 0)
 237     return Molecule ();
 238   if (points.size () == 1)
 239     return dot (points[0], 0.5 * blotdiameter);
 240   if (points.size () == 2)
 241     return line (blotdiameter, points[0], points[1]);
 242
 243   /* shrink polygon in size by 0.5 * blotdiameter */
 244   Array<Offset> shrinked_points;
 245   shrinked_points.set_size (points.size ());
 246   bool ccw = 1; // true, if three adjacent points are counterclockwise ordered
 247   for (int i = 0; i < points.size (); i++)
 248     {
 249       int i0 = i;
 250       int i1 = (i + 1) % points.size ();
 251       int i2 = (i + 2) % points.size ();
 252       Offset p0 = points[i0];
 253       Offset p1 = points[i1];
 254       Offset p2 = points[i2];
 255       Offset p10 = p0 - p1;
 256       Offset p12 = p2 - p1;
 257       if (p10.length () != 0.0)
 258         { // recompute ccw
 259           Real phi = p10.arg ();
 260           // rotate (p2 - p0) by (-phi)
 261           Offset q = complex_multiply (p2 - p0, complex_exp (Offset (1.0, -phi)));
 262
 263           if (q[Y_AXIS] > 0)
 264             ccw = 1;
 265           else if (q[Y_AXIS] < 0)
 266             ccw = 0;
 267           else {} // keep ccw unchanged
 268         }
 269       else {} // keep ccw unchanged
 270       Offset p10n = (1.0 / p10.length ()) * p10; // normalize length to 1.0
 271       Offset p12n = (1.0 / p12.length ()) * p12;
 272       Offset p13n = 0.5 * (p10n + p12n);
 273       Offset p14n = 0.5 * (p10n - p12n);
 274       Offset p13;
 275       Real d = p13n.length () * p14n.length (); // distance p3n to line(p1..p0)
 276       if (d < epsilon)
 277         // special case: p0, p1, p2 are on a single line => build
 278         // vector orthogonal to (p2-p0) of length 0.5 blotdiameter
 279         {
 280           p13[X_AXIS] = p10[Y_AXIS];
 281           p13[Y_AXIS] = -p10[X_AXIS];
 282           p13 = (0.5 * blotdiameter / p13.length ()) * p13;
 283         }
 284       else
 285         p13 = (0.5 * blotdiameter / d) * p13n;
 286       shrinked_points[i1] = p1 + ((ccw) ? p13 : -p13);
 287     }
 288
 289   /* build scm expression and bounding box */
 290   SCM shrinked_points_scm = SCM_EOL;
 291   Box box;
 292   for (int i = 0; i < shrinked_points.size (); i++)
 293     {
 294       SCM x = gh_double2scm (shrinked_points[i][X_AXIS]);
 295       SCM y = gh_double2scm (shrinked_points[i][Y_AXIS]);
 296       shrinked_points_scm = gh_cons (x, gh_cons (y, shrinked_points_scm));
 297       box.add_point (points[i]);
 298     }
 299   SCM polygon_scm = scm_list_n (ly_symbol2scm ("polygon"),
 300                                 ly_quote_scm (shrinked_points_scm),
 301                                 gh_double2scm (blotdiameter),
 302                                 SCM_UNDEFINED);
 303
 304   Molecule polygon = Molecule (box, polygon_scm);
 305   shrinked_points.clear ();
 306   return polygon;
 307 }
 308
 309 Molecule
 310 Lookup::frame (Box b, Real thick)
 311 {
 312   Molecule m;
 313   Direction d = LEFT;
 314   for (Axis a = X_AXIS; a < NO_AXES; a = Axis (a + 1))
 315     {
 316       Axis o = Axis ((a+1)%NO_AXES);
 317       do
 318         {
 319           Box edges;
 320           edges[a] = b[a][d] + 0.5 * thick * Interval (-1, 1);
 321           edges[o][DOWN] = b[o][DOWN] - thick/2;
 322           edges[o][UP] = b[o][UP] + thick/2;
 323
 324           m.add_molecule (filledbox (edges));
 325         }
 326       while (flip (&d) != LEFT);
 327     }
 328   return m;
 329
 330 }
 331
 332 /*
 333   Make a smooth curve along the points
 334  */
 335 Molecule
 336 Lookup::slur (Bezier curve, Real curvethick, Real linethick)
 337 {
 338   Real alpha = (curve.control_[3] - curve.control_[0]).arg ();
 339   Bezier back = curve;
 340   Offset perp = curvethick * complex_exp (Offset (0, alpha + M_PI/2)) * 0.5;
 341   back.reverse ();
 342   back.control_[1] += perp;
 343   back.control_[2] += perp;
 344
 345   curve.control_[1] -= perp;
 346   curve.control_[2] -= perp;
 347
 348   SCM scontrols[8];
 349
 350   for (int i=4; i--;)
 351     scontrols[ i ] = ly_offset2scm (back.control_[i]);
 352   for (int i=4 ; i--;)
 353     scontrols[i+4] = ly_offset2scm (curve.control_[i]);
 354
 355   /*
 356     Need the weird order b.o. the way PS want its arguments
 357    */
 358   int indices[]= {5, 6, 7, 4, 1, 2, 3, 0};
 359   SCM list = SCM_EOL;
 360   for (int i= 8; i--;)
 361     {
 362       list = gh_cons (scontrols[indices[i]], list);
 363     }
 364
 365
 366   SCM at = (scm_list_n (ly_symbol2scm ("bezier-bow"),
 367                      ly_quote_scm (list),
 368                      gh_double2scm (linethick),
 369                      SCM_UNDEFINED));
 370   Box b(curve.extent (X_AXIS),
 371         curve.extent (Y_AXIS));
 372
 373   b[X_AXIS].unite (back.extent (X_AXIS));
 374   b[Y_AXIS].unite (back.extent (Y_AXIS));
 375
 376   return Molecule (b, at);
 377 }
 378
 379 /*
 380  * Bezier Sandwich:
 381  *
 382  *                               .|
 383  *                        .       |
 384  *              top .             |
 385  *              . curve           |
 386  *          .                     |
 387  *       .                        |
 388  *     .                          |
 389  *    |                           |
 390  *    |                          .|
 391  *    |                     .
 392  *    |         bottom .
 393  *    |            . curve
 394  *    |         .
 395  *    |      .
 396  *    |   .
 397  *    | .
 398  *    |.
 399  *    |
 400  *
 401  */
 402 Molecule
 403 Lookup::bezier_sandwich (Bezier top_curve, Bezier bottom_curve)
 404 {
 405   /*
 406     Need the weird order b.o. the way PS want its arguments
 407    */
 408   SCM list = SCM_EOL;
 409   list = gh_cons (ly_offset2scm (bottom_curve.control_[3]), list);
 410   list = gh_cons (ly_offset2scm (bottom_curve.control_[0]), list);
 411   list = gh_cons (ly_offset2scm (bottom_curve.control_[1]), list);
 412   list = gh_cons (ly_offset2scm (bottom_curve.control_[2]), list);
 413   list = gh_cons (ly_offset2scm (top_curve.control_[0]), list);
 414   list = gh_cons (ly_offset2scm (top_curve.control_[3]), list);
 415   list = gh_cons (ly_offset2scm (top_curve.control_[2]), list);
 416   list = gh_cons (ly_offset2scm (top_curve.control_[1]), list);
 417
 418   SCM horizontal_bend = scm_list_n (ly_symbol2scm ("bezier-sandwich"),
 419                                     ly_quote_scm (list),
 420                                     gh_double2scm (0.0),
 421                                     SCM_UNDEFINED);
 422
 423   Interval x_extent = top_curve.extent (X_AXIS);
 424   x_extent.unite (bottom_curve.extent (X_AXIS));
 425   Interval y_extent = top_curve.extent (Y_AXIS);
 426   y_extent.unite (bottom_curve.extent (Y_AXIS));
 427   Box b (x_extent, y_extent);
 428
 429   return Molecule (b, horizontal_bend);
 430 }
 431
 432 /*
 433  * Horizontal Slope:
 434  *
 435  *            /|   ^
 436  *           / |   |
 437  *          /  |   | height
 438  *         /   |   |
 439  *        /    |   v
 440  *       |    /
 441  *       |   /
 442  * (0,0) x  /slope=dy/dx
 443  *       | /
 444  *       |/
 445  *
 446  *       <----->
 447  *        width
 448  */
 449 Molecule
 450 Lookup::horizontal_slope (Real width, Real slope, Real height)
 451 {
 452   SCM width_scm = gh_double2scm (width);
 453   SCM slope_scm = gh_double2scm (slope);
 454   SCM height_scm = gh_double2scm (height);
 455   SCM horizontal_slope = scm_list_n (ly_symbol2scm ("beam"),
 456                                      width_scm, slope_scm,
 457                                      height_scm, SCM_UNDEFINED);
 458   Box b (Interval (0, width),
 459          Interval (-height/2, height/2 + width*slope));
 460   return Molecule (b, horizontal_slope);
 461 }
 462
 463 /*
 464   TODO: junk me.
 465  */
 466 Molecule
 467 Lookup::accordion (SCM s, Real staff_space, Font_metric *fm)
 468 {
 469   Molecule m;
 470   String sym = ly_scm2string (ly_car (s));
 471   String reg = ly_scm2string (ly_car (ly_cdr (s)));
 472
 473   if (sym == "Discant")
 474     {
 475       Molecule r = fm->find_by_name ("accordion-accDiscant");
 476       m.add_molecule (r);
 477       if (reg.left_string (1) == "F")
 478         {
 479           Molecule d = fm->find_by_name ("accordion-accDot");
 480           d.translate_axis (staff_space * 2.5 PT, Y_AXIS);
 481           m.add_molecule (d);
 482           reg = reg.right_string (reg.length ()-1);
 483         }
 484       int eflag = 0x00;
 485       if (reg.left_string (3) == "EEE")
 486         {
 487           eflag = 0x07;
 488           reg = reg.right_string (reg.length ()-3);
 489         }
 490       else if (reg.left_string (2) == "EE")
 491         {
 492           eflag = 0x05;
 493           reg = reg.right_string (reg.length ()-2);
 494         }
 495       else if (reg.left_string (2) == "Eh")
 496         {
 497           eflag = 0x04;
 498           reg = reg.right_string (reg.length ()-2);
 499         }
 500       else if (reg.left_string (1) == "E")
 501         {
 502           eflag = 0x02;
 503           reg = reg.right_string (reg.length ()-1);
 504         }
 505       if (eflag & 0x02)
 506         {
 507           Molecule d = fm->find_by_name ("accordion-accDot");
 508           d.translate_axis (staff_space * 1.5 PT, Y_AXIS);
 509           m.add_molecule (d);
 510         }
 511       if (eflag & 0x04)
 512         {
 513           Molecule d = fm->find_by_name ("accordion-accDot");
 514           d.translate_axis (staff_space * 1.5 PT, Y_AXIS);
 515           d.translate_axis (0.8 * staff_space PT, X_AXIS);
 516           m.add_molecule (d);
 517         }
 518       if (eflag & 0x01)
 519         {
 520           Molecule d = fm->find_by_name ("accordion-accDot");
 521           d.translate_axis (staff_space * 1.5 PT, Y_AXIS);
 522           d.translate_axis (-0.8 * staff_space PT, X_AXIS);
 523           m.add_molecule (d);
 524         }
 525       if (reg.left_string (2) == "SS")
 526         {
 527           Molecule d = fm->find_by_name ("accordion-accDot");
 528           d.translate_axis (0.5 * staff_space PT, Y_AXIS);
 529           d.translate_axis (0.4 * staff_space PT, X_AXIS);
 530           m.add_molecule (d);
 531           d.translate_axis (-0.8 * staff_space PT, X_AXIS);
 532           m.add_molecule (d);
 533           reg = reg.right_string (reg.length ()-2);
 534         }
 535       if (reg.left_string (1) == "S")
 536         {
 537           Molecule d = fm->find_by_name ("accordion-accDot");
 538           d.translate_axis (0.5 * staff_space PT, Y_AXIS);
 539           m.add_molecule (d);
 540           reg = reg.right_string (reg.length ()-1);
 541         }
 542     }
 543   else if (sym == "Freebase")
 544     {
 545       Molecule r = fm->find_by_name ("accordion-accFreebase");
 546       m.add_molecule (r);
 547       if (reg.left_string (1) == "F")
 548         {
 549           Molecule d = fm->find_by_name ("accordion-accDot");
 550           d.translate_axis (staff_space * 1.5 PT, Y_AXIS);
 551           m.add_molecule (d);
 552           reg = reg.right_string (reg.length ()-1);
 553         }
 554       if (reg == "E")
 555         {
 556           Molecule d = fm->find_by_name ("accordion-accDot");
 557           d.translate_axis (staff_space * 0.5 PT, Y_AXIS);
 558           m.add_molecule (d);
 559         }
 560     }
 561   else if (sym == "Bayanbase")
 562     {
 563       Molecule r = fm->find_by_name ("accordion-accBayanbase");
 564       m.add_molecule (r);
 565       if (reg.left_string (1) == "T")
 566         {
 567           Molecule d = fm->find_by_name ("accordion-accDot");
 568           d.translate_axis (staff_space * 2.5 PT, Y_AXIS);
 569           m.add_molecule (d);
 570           reg = reg.right_string (reg.length ()-1);
 571         }
 572       /* include 4' reed just for completeness. You don't want to use this. */
 573       if (reg.left_string (1) == "F")
 574         {
 575           Molecule d = fm->find_by_name ("accordion-accDot");
 576           d.translate_axis (staff_space * 1.5 PT, Y_AXIS);
 577           m.add_molecule (d);
 578           reg = reg.right_string (reg.length ()-1);
 579         }
 580       if (reg.left_string (2) == "EE")
 581         {
 582           Molecule d = fm->find_by_name ("accordion-accDot");
 583           d.translate_axis (staff_space * 0.5 PT, Y_AXIS);
 584           d.translate_axis (0.4 * staff_space PT, X_AXIS);
 585           m.add_molecule (d);
 586           d.translate_axis (-0.8 * staff_space PT, X_AXIS);
 587           m.add_molecule (d);
 588           reg = reg.right_string (reg.length ()-2);
 589         }
 590       if (reg.left_string (1) == "E")
 591         {
 592           Molecule d = fm->find_by_name ("accordion-accDot");
 593           d.translate_axis (staff_space * 0.5 PT, Y_AXIS);
 594           m.add_molecule (d);
 595           reg = reg.right_string (reg.length ()-1);
 596         }
 597     }
 598   else if (sym == "Stdbase")
 599     {
 600       Molecule r = fm->find_by_name ("accordion-accStdbase");
 601       m.add_molecule (r);
 602       if (reg.left_string (1) == "T")
 603         {
 604           Molecule d = fm->find_by_name ("accordion-accDot");
 605           d.translate_axis (staff_space * 3.5 PT, Y_AXIS);
 606           m.add_molecule (d);
 607           reg = reg.right_string (reg.length ()-1);
 608         }
 609       if (reg.left_string (1) == "F")
 610         {
 611           Molecule d = fm->find_by_name ("accordion-accDot");
 612           d.translate_axis (staff_space * 2.5 PT, Y_AXIS);
 613           m.add_molecule (d);
 614           reg = reg.right_string (reg.length ()-1);
 615         }
 616       if (reg.left_string (1) == "M")
 617         {
 618           Molecule d = fm->find_by_name ("accordion-accDot");
 619           d.translate_axis (staff_space * 2 PT, Y_AXIS);
 620           d.translate_axis (staff_space PT, X_AXIS);
 621           m.add_molecule (d);
 622           reg = reg.right_string (reg.length ()-1);
 623         }
 624       if (reg.left_string (1) == "E")
 625         {
 626           Molecule d = fm->find_by_name ("accordion-accDot");
 627           d.translate_axis (staff_space * 1.5 PT, Y_AXIS);
 628           m.add_molecule (d);
 629           reg = reg.right_string (reg.length ()-1);
 630         }
 631       if (reg.left_string (1) == "S")
 632         {
 633           Molecule d = fm->find_by_name ("accordion-accDot");
 634           d.translate_axis (staff_space * 0.5 PT, Y_AXIS);
 635           m.add_molecule (d);
 636           reg = reg.right_string (reg.length ()-1);
 637         }
 638     }
 639   /* ugh maybe try to use regular font for S.B. and B.B and only use one font
 640      for the rectangle */
 641   else if (sym == "SB")
 642     {
 643       Molecule r = fm->find_by_name ("accordion-accSB");
 644       m.add_molecule (r);
 645     }
 646   else if (sym == "BB")
 647     {
 648       Molecule r = fm->find_by_name ("accordion-accBB");
 649       m.add_molecule (r);
 650     }
 651   else if (sym == "OldEE")
 652     {
 653       Molecule r = fm->find_by_name ("accordion-accOldEE");
 654       m.add_molecule (r);
 655     }
 656   else if (sym == "OldEES")
 657     {
 658       Molecule r = fm->find_by_name ("accordion-accOldEES");
 659       m.add_molecule (r);
 660     }
 661   return m;
 662 }
 663
 664 Molecule
 665 Lookup::repeat_slash (Real w, Real s, Real t)
 666 {
 667   SCM wid = gh_double2scm (w);
 668   SCM sl = gh_double2scm (s);
 669   SCM thick = gh_double2scm (t);
 670   SCM slashnodot = scm_list_n (ly_symbol2scm ("repeat-slash"),
 671                             wid, sl, thick, SCM_UNDEFINED);
 672
 673   Box b (Interval (0, w + sqrt (sqr(t/s) + sqr (t))),
 674          Interval (0, w * s));
 675
 676   return Molecule (b, slashnodot); //  http://slashnodot.org
 677 }
 678
 679 Molecule
 680 Lookup::bracket (Axis a, Interval iv, Real thick, Real protude)
 681 {
 682   Box b;
 683   Axis other = Axis((a+1)%2);
 684   b[a] = iv;
 685   b[other] = Interval(-1, 1) * thick * 0.5;
 686
 687   Molecule m =  filledbox (b);
 688
 689   b[a] = Interval (iv[UP] - thick, iv[UP]);
 690   Interval oi = Interval (-thick/2, thick/2 + fabs (protude)) ;
 691   oi *=  sign (protude);
 692   b[other] = oi;
 693   m.add_molecule (filledbox (b));
 694   b[a] = Interval (iv[DOWN], iv[DOWN]  +thick);
 695   m.add_molecule (filledbox(b));
 696
 697   return m;
 698 }
 699
 700 Molecule
 701 Lookup::triangle (Interval iv, Real thick, Real protude)
 702 {
 703   Box b ;
 704   b[X_AXIS] = iv;
 705   b[Y_AXIS] = Interval (0 <? protude , 0 >? protude);
 706
 707   SCM s = scm_list_n (ly_symbol2scm ("symmetric-x-triangle"),
 708                       gh_double2scm (thick),
 709                       gh_double2scm (iv.length()),
 710                       gh_double2scm (protude), SCM_UNDEFINED);
 711
 712   return Molecule (b, s);
 713 }
 714
 715
 716 /*
 717   TODO: use rounded boxes.
 718  */
 719 LY_DEFINE(ly_bracket ,"ly:bracket",
 720           4, 0, 0,
 721           (SCM a, SCM iv, SCM t, SCM p),
 722           "Make a bracket in direction @var{a}. The extent of the bracket is "
 723           "given by @var{iv}. The wings protude by an amount of @var{p}, which "
 724           "may be negative. The thickness is given by @var{t}.")
 725 {
 726   SCM_ASSERT_TYPE(ly_axis_p (a), a, SCM_ARG1, __FUNCTION__, "axis") ;
 727   SCM_ASSERT_TYPE(ly_number_pair_p (iv), iv, SCM_ARG2, __FUNCTION__, "number pair") ;
 728   SCM_ASSERT_TYPE(gh_number_p (t), a, SCM_ARG3, __FUNCTION__, "number") ;
 729   SCM_ASSERT_TYPE(gh_number_p (p), a, SCM_ARG4, __FUNCTION__, "number") ;
 730
 731
 732   return Lookup::bracket ((Axis)gh_scm2int (a), ly_scm2interval (iv),
 733                           gh_scm2double (t),
 734                           gh_scm2double (p)).smobbed_copy ();
 735 }
 736