font.c

   1 /* font handling */
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <string.h>
   5 #include "roff.h"
   6
   7 /* convert wid in device unitwidth size to size sz */
   8 #define DEVWID(sz, wid)         (((wid) * (sz) + (dev_uwid / 2)) / dev_uwid)
   9
  10 /* flags for gpat->flg */
  11 #define GF_PAT          1       /* gsub/gpos pattern glyph */
  12 #define GF_REP          2       /* gsub replacement glyph */
  13 #define GF_CON          4       /* context glyph */
  14 #define GF_GRP          8       /* glyph group */
  15
  16 /* glyph substitution and positioning rules */
  17 struct grule {
  18         struct gpat {                   /* rule description */
  19                 short g;                /* glyph index */
  20                 short flg;              /* pattern flags; GF_* */
  21                 short x, y, xadv, yadv; /* gpos data */
  22         } *pats;                        /* rule pattern */
  23         short len;                      /* pats[] length */
  24         short feat, scrp, lang;         /* rule's feature and script */
  25 };
  26
  27 struct font {
  28         char name[FNLEN];
  29         char fontname[FNLEN];
  30         int spacewid;
  31         int special;
  32         int cs, cs_ps, bd, zoom;        /* for .cs, .bd, .fzoom requests */
  33         int s1, n1, s2, n2;             /* for .tkf request */
  34         struct glyph *gl;               /* glyphs present in the font */
  35         int gl_n, gl_sz;                /* number of glyphs in the font */
  36         struct dict *gl_dict;           /* mapping from gl[i].id to i */
  37         struct dict *ch_dict;           /* charset mapping */
  38         struct dict *ch_map;            /* characters mapped via font_map() */
  39         /* font features and scripts */
  40         char feat_name[NFEATS][8];      /* feature names */
  41         int feat_set[NFEATS];           /* feature enabled */
  42         char scrp_name[NSCRPS][8];      /* script names */
  43         int scrp;                       /* current script */
  44         char lang_name[NLANGS][8];      /* language names */
  45         int lang;                       /* current language */
  46         /* glyph substitution and positioning */
  47         struct grule *gsub;             /* glyph substitution rules */
  48         int gsub_n, gsub_sz;
  49         struct grule *gpos;             /* glyph positioning rules */
  50         int gpos_n, gpos_sz;
  51         struct iset *gsub0;             /* rules matching a glyph at pos 0 */
  52         struct iset *gpos0;             /* rules matching a glyph at pos 0 */
  53         struct iset *ggrp;              /* glyph groups */
  54 };
  55
  56 /* find a glyph by its name */
  57 struct glyph *font_find(struct font *fn, char *name)
  58 {
  59         int i = dict_get(fn->ch_map, name);
  60         if (i == -1)            /* -2 means the glyph has been unmapped */
  61                 i = dict_get(fn->ch_dict, name);
  62         return i >= 0 ? fn->gl + i : NULL;
  63 }
  64
  65 /* find a glyph by its device-dependent identifier */
  66 struct glyph *font_glyph(struct font *fn, char *id)
  67 {
  68         int i = dict_get(fn->gl_dict, id);
  69         return i >= 0 ? &fn->gl[i] : NULL;
  70 }
  71
  72 static int font_glyphput(struct font *fn, char *id, char *name, int type)
  73 {
  74         struct glyph *g;
  75         if (fn->gl_n == fn->gl_sz) {
  76                 fn->gl_sz = fn->gl_sz + 1024;
  77                 fn->gl = mextend(fn->gl, fn->gl_n, fn->gl_sz, sizeof(fn->gl[0]));
  78         }
  79         g = &fn->gl[fn->gl_n];
  80         snprintf(g->id, sizeof(g->id), "%s", id);
  81         snprintf(g->name, sizeof(g->name), "%s", name);
  82         g->type = type;
  83         g->font = fn;
  84         dict_put(fn->gl_dict, g->id, fn->gl_n);
  85         return fn->gl_n++;
  86 }
  87
  88 /* map character name to the given glyph; remove the mapping if id is NULL */
  89 int font_map(struct font *fn, char *name, char *id)
  90 {
  91         int gidx = -1;
  92         if (id)
  93                 gidx = font_glyph(fn, id) ? font_glyph(fn, id) - fn->gl : -2;
  94         dict_put(fn->ch_map, name, gidx);
  95         return 0;
  96 }
  97
  98 /* return nonzero if character name has been mapped with font_map() */
  99 int font_mapped(struct font *fn, char *name)
 100 {
 101         return dict_get(fn->ch_map, name) != -1;
 102 }
 103
 104 static int font_findfeat(struct font *fn, char *feat);
 105
 106 /* enable/disable ligatures; first bit for liga and the second bit for rlig */
 107 static int font_featlg(struct font *fn, int val)
 108 {
 109         int ret = 0;
 110         ret |= font_feat(fn, "liga", val & 1);
 111         ret |= font_feat(fn, "rlig", val & 2) << 1;
 112         return ret;
 113 }
 114
 115 /* enable/disable pairwise kerning */
 116 static int font_featkn(struct font *fn, int val)
 117 {
 118         return font_feat(fn, "kern", val);
 119 }
 120
 121 /* glyph index in fn->glyphs[] */
 122 static int font_idx(struct font *fn, struct glyph *g)
 123 {
 124         return g ? g - fn->gl : -1;
 125 }
 126
 127 static int font_gpatmatch(struct font *fn, struct gpat *p, int g)
 128 {
 129         int *r;
 130         if (!(p->flg & GF_GRP))
 131                 return p->g == g;
 132         r = iset_get(fn->ggrp, p->g);
 133         while (r && *r >= 0)
 134                 if (*r++ == g)
 135                         return 1;
 136         return 0;
 137 }
 138
 139 static int font_rulematch(struct font *fn, struct grule *rule,
 140                         int *src, int slen, int *dst, int dlen)
 141 {
 142         int sidx = 0;           /* the index of matched glyphs in src */
 143         int ncon = 0;           /* number of initial context glyphs */
 144         struct gpat *pats = rule->pats;
 145         int j;
 146         /* enable only the active script if set */
 147         if (fn->scrp >= 0 && fn->scrp != rule->scrp)
 148                 return 0;
 149         /* enable common script features and those in the active language */
 150         if (rule->lang >= 0 && fn->lang != rule->lang)
 151                 return 0;
 152         if (!fn->feat_set[rule->feat])
 153                 return 0;
 154         /* the number of initial context glyphs */
 155         for (j = 0; j < rule->len && pats[j].flg & GF_CON; j++)
 156                 ncon++;
 157         if (dlen < ncon)
 158                 return 0;
 159         /* matching the base pattern */
 160         for (; j < rule->len; j++) {
 161                 if (pats[j].flg & GF_REP)
 162                         continue;
 163                 if (sidx >= slen || !font_gpatmatch(fn, &pats[j], src[sidx]))
 164                         return 0;
 165                 sidx++;
 166         }
 167         /* matching the initial context */
 168         for (j = 0; j < rule->len && pats[j].flg & GF_CON; j++)
 169                 if (!font_gpatmatch(fn, &pats[j], dst[j - ncon]))
 170                         return 0;
 171         return 1;
 172 }
 173
 174 /* find a matching gsub/gpos rule; *idx should be -1 initially */
 175 static int font_findrule(struct font *fn, int gsub, int pos,
 176                 int *fwd, int fwdlen, int *ctx, int ctxlen, int *idx)
 177 {
 178         struct grule *rules = gsub ? fn->gsub : fn->gpos;
 179         int *r1 = iset_get(gsub ? fn->gsub0 : fn->gpos0, fwd[0]);
 180         while (r1 && r1[++*idx] >= 0) {
 181                 if (r1[*idx] >= pos && font_rulematch(fn, &rules[r1[*idx]],
 182                                                 fwd, fwdlen, ctx, ctxlen))
 183                         return r1[*idx];
 184         }
 185         return -1;
 186 }
 187
 188 /* perform all possible gpos rules on src */
 189 static void font_performgpos(struct font *fn, int *src, int slen,
 190                 int *x, int *y, int *xadv, int *yadv)
 191 {
 192         struct grule *gpos = fn->gpos;
 193         struct gpat *pats;
 194         int curs_feat = dir_do ? font_findfeat(fn, "curs") : -1;
 195         int curs_beg = -1;
 196         int curs_dif = 0;
 197         int i, k;
 198         for (i = 0; i < slen; i++) {
 199                 int idx = -1;
 200                 int curs_cur = 0;
 201                 while (1) {
 202                         int r = font_findrule(fn, 0, 0, src + i, slen - i,
 203                                                 src + i, i, &idx);
 204                         if (r < 0)
 205                                 break;
 206                         pats = gpos[r].pats;
 207                         for (k = 0; k < gpos[r].len; k++) {
 208                                 x[i + k] += pats[k].x;
 209                                 y[i + k] += pats[k].y;
 210                                 xadv[i + k] += pats[k].xadv;
 211                                 yadv[i + k] += pats[k].yadv;
 212                         }
 213                         if (gpos[r].feat == curs_feat) {
 214                                 curs_cur = 1;
 215                                 if (curs_beg < 0)
 216                                         curs_beg = i;
 217                                 for (k = 0; k < gpos[r].len; k++)
 218                                         curs_dif += pats[k].yadv;
 219                         }
 220                 }
 221                 if (curs_beg >= 0 && !curs_cur) {
 222                         yadv[curs_beg] -= curs_dif;
 223                         curs_beg = -1;
 224                         curs_dif = 0;
 225                 }
 226         }
 227         if (curs_beg >= 0)
 228                 yadv[curs_beg] -= curs_dif;
 229 }
 230
 231 /* find the first gsub rule after pos that matches any glyph in src */
 232 static int font_firstgsub(struct font *fn, int pos, int *src, int slen)
 233 {
 234         int best = -1;
 235         int i;
 236         for (i = 0; i < slen; i++) {
 237                 int idx = -1;
 238                 int r = font_findrule(fn, 1, pos, src + i, slen - i,
 239                                         src + i, i, &idx);
 240                 if (r >= 0 && (best < 0 || r < best))
 241                         best = r;
 242         }
 243         return best;
 244 }
 245
 246 /* apply the given gsub rule to all matches in src */
 247 static int font_gsubapply(struct font *fn, struct grule *rule,
 248                         int *src, int slen, int *smap)
 249 {
 250         int dst[WORDLEN];
 251         int dlen = 0;
 252         int dmap[WORDLEN];
 253         int i, j;
 254         memset(dmap, 0, slen * sizeof(dmap[i]));
 255         for (i = 0; i < slen; i++) {
 256                 dmap[dlen] = smap[i];
 257                 if (font_rulematch(fn, rule, src + i, slen - i,
 258                                         dst + dlen, dlen)) {
 259                         for (j = 0; j < rule->len; j++) {
 260                                 if (rule->pats[j].flg & GF_REP)
 261                                         dst[dlen++] = rule->pats[j].g;
 262                                 if (rule->pats[j].flg & GF_PAT)
 263                                         i++;
 264                         }
 265                         i--;
 266                 } else {
 267                         dst[dlen++] = src[i];
 268                 }
 269         }
 270         memcpy(src, dst, dlen * sizeof(dst[0]));
 271         memcpy(smap, dmap, dlen * sizeof(dmap[0]));
 272         return dlen;
 273 }
 274
 275 /* perform all possible gsub rules on src */
 276 static int font_performgsub(struct font *fn, int *src, int slen, int *smap)
 277 {
 278         int i = -1;
 279         while (++i >= 0) {
 280                 if ((i = font_firstgsub(fn, i, src, slen)) < 0)
 281                         break;
 282                 slen = font_gsubapply(fn, &fn->gsub[i], src, slen, smap);
 283         }
 284         return slen;
 285 }
 286
 287 int font_layout(struct font *fn, struct glyph **gsrc, int nsrc, int sz,
 288                 struct glyph **gdst, int *dmap,
 289                 int *x, int *y, int *xadv, int *yadv, int lg, int kn)
 290 {
 291         int dst[WORDLEN];
 292         int ndst = nsrc;
 293         int i;
 294         int featlg, featkn;
 295         /* initialising dst */
 296         for (i = 0; i < nsrc; i++)
 297                 dst[i] = font_idx(fn, gsrc[i]);
 298         for (i = 0; i < ndst; i++)
 299                 dmap[i] = i;
 300         memset(x, 0, ndst * sizeof(x[0]));
 301         memset(y, 0, ndst * sizeof(y[0]));
 302         memset(xadv, 0, ndst * sizeof(xadv[0]));
 303         memset(yadv, 0, ndst * sizeof(yadv[0]));
 304         /* substitution rules */
 305         if (lg)
 306                 featlg = font_featlg(fn, 3);
 307         ndst = font_performgsub(fn, dst, ndst, dmap);
 308         if (lg)
 309                 font_featlg(fn, featlg);
 310         /* positioning rules */
 311         if (kn)
 312                 featkn = font_featkn(fn, 1);
 313         font_performgpos(fn, dst, ndst, x, y, xadv, yadv);
 314         if (kn)
 315                 font_featkn(fn, featkn);
 316         for (i = 0; i < ndst; i++)
 317                 gdst[i] = fn->gl + dst[i];
 318         return ndst;
 319 }
 320
 321 static int font_readchar(struct font *fn, FILE *fin, int *n, int *gid)
 322 {
 323         struct glyph *g;
 324         char tok[ILNLEN];
 325         char name[ILNLEN];
 326         char id[ILNLEN];
 327         int type;
 328         if (fscanf(fin, "%s %s", name, tok) != 2)
 329                 return 1;
 330         if (!strcmp("---", name))
 331                 sprintf(name, "c%04d", *n);
 332         if (strcmp("\"", tok)) {
 333                 if (fscanf(fin, "%d %s", &type, id) != 2)
 334                         return 1;
 335                 *gid = font_glyphput(fn, id, name, type);
 336                 g = &fn->gl[*gid];
 337                 sscanf(tok, "%hd,%hd,%hd,%hd,%hd", &g->wid,
 338                         &g->llx, &g->lly, &g->urx, &g->ury);
 339                 dict_put(fn->ch_dict, name, *gid);
 340                 (*n)++;
 341         } else {
 342                 dict_put(fn->ch_map, name, *gid);
 343         }
 344         return 0;
 345 }
 346
 347 static int font_findfeat(struct font *fn, char *feat)
 348 {
 349         int i;
 350         for (i = 0; i < LEN(fn->feat_name) && fn->feat_name[i][0]; i++)
 351                 if (!strcmp(feat, fn->feat_name[i]))
 352                         return i;
 353         if (i < LEN(fn->feat_name)) {
 354                 snprintf(fn->feat_name[i], sizeof(fn->feat_name[i]), "%s", feat);
 355                 return i;
 356         }
 357         return -1;
 358 }
 359
 360 static int font_findscrp(struct font *fn, char *scrp)
 361 {
 362         int i;
 363         for (i = 0; i < LEN(fn->scrp_name) && fn->scrp_name[i][0]; i++)
 364                 if (!strcmp(scrp, fn->scrp_name[i]))
 365                         return i;
 366         if (i == LEN(fn->scrp_name))
 367                 return -1;
 368         snprintf(fn->scrp_name[i], sizeof(fn->scrp_name[i]), "%s", scrp);
 369         return i;
 370 }
 371
 372 static int font_findlang(struct font *fn, char *lang)
 373 {
 374         int i;
 375         for (i = 0; i < LEN(fn->lang_name) && fn->lang_name[i][0]; i++)
 376                 if (!strcmp(lang, fn->lang_name[i]))
 377                         return i;
 378         if (i == LEN(fn->lang_name))
 379                 return -1;
 380         snprintf(fn->lang_name[i], sizeof(fn->lang_name[i]), "%s", lang);
 381         return i;
 382 }
 383
 384 static struct gpat *font_gpat(struct font *fn, int len)
 385 {
 386         struct gpat *pats = xmalloc(len * sizeof(pats[0]));
 387         memset(pats, 0, len * sizeof(pats[0]));
 388         return pats;
 389 }
 390
 391 static struct grule *font_gsub(struct font *fn, int len, int feat, int scrp, int lang)
 392 {
 393         struct grule *rule;
 394         struct gpat *pats = font_gpat(fn, len);
 395         if (fn->gsub_n  == fn->gsub_sz) {
 396                 fn->gsub_sz = fn->gsub_sz + 1024;
 397                 fn->gsub = mextend(fn->gsub, fn->gsub_n, fn->gsub_sz,
 398                                 sizeof(fn->gsub[0]));
 399         }
 400         rule = &fn->gsub[fn->gsub_n++];
 401         rule->pats = pats;
 402         rule->len = len;
 403         rule->feat = feat;
 404         rule->scrp = scrp;
 405         rule->lang = lang;
 406         return rule;
 407 }
 408
 409 static struct grule *font_gpos(struct font *fn, int len, int feat, int scrp, int lang)
 410 {
 411         struct grule *rule;
 412         struct gpat *pats = font_gpat(fn, len);
 413         if (fn->gpos_n == fn->gpos_sz) {
 414                 fn->gpos_sz = fn->gpos_sz + 1024;
 415                 fn->gpos = mextend(fn->gpos, fn->gpos_n, fn->gpos_sz,
 416                                 sizeof(fn->gpos[0]));
 417         }
 418         rule = &fn->gpos[fn->gpos_n++];
 419         rule->pats = pats;
 420         rule->len = len;
 421         rule->feat = feat;
 422         rule->scrp = scrp;
 423         rule->lang = lang;
 424         return rule;
 425 }
 426
 427 static int font_readgpat(struct font *fn, struct gpat *p, char *s)
 428 {
 429         if (s[0] == '@') {
 430                 p->g = atoi(s + 1);
 431                 if (iset_len(fn->ggrp, p->g) == 1)
 432                         p->g = iset_get(fn->ggrp, p->g)[0];
 433                 else
 434                         p->flg |= GF_GRP;
 435         } else {
 436                 p->g = font_idx(fn, font_glyph(fn, s));
 437         }
 438         return p->g < 0;
 439 }
 440
 441 static void font_readfeat(struct font *fn, char *tok, int *feat, int *scrp, int *lang)
 442 {
 443         char *ftag = tok;
 444         char *stag = NULL;
 445         char *ltag = NULL;
 446         *scrp = -1;
 447         *lang = -1;
 448         if (strchr(ftag, ':')) {
 449                 stag = strchr(ftag, ':') + 1;
 450                 stag[-1] = '\0';
 451         }
 452         if (strchr(stag, ':')) {
 453                 ltag = strchr(stag, ':') + 1;
 454                 ltag[-1] = '\0';
 455         }
 456         if (stag)
 457                 *scrp = font_findscrp(fn, stag);
 458         if (ltag)
 459                 *lang = font_findlang(fn, ltag);
 460         *feat = font_findfeat(fn, tok);
 461 }
 462
 463 static int font_readgsub(struct font *fn, FILE *fin)
 464 {
 465         char tok[128];
 466         struct grule *rule;
 467         int feat, scrp, lang;
 468         int i, n;
 469         if (fscanf(fin, "%s %d", tok, &n) != 2)
 470                 return 1;
 471         font_readfeat(fn, tok, &feat, &scrp, &lang);
 472         rule = font_gsub(fn, n, feat, scrp, lang);
 473         for (i = 0; i < n; i++) {
 474                 if (fscanf(fin, "%s", tok) != 1)
 475                         return 1;
 476                 if (tok[0] == '-')
 477                         rule->pats[i].flg = GF_PAT;
 478                 if (tok[0] == '=')
 479                         rule->pats[i].flg = GF_CON;
 480                 if (tok[0] == '+')
 481                         rule->pats[i].flg = GF_REP;
 482                 if (!tok[0] || font_readgpat(fn, &rule->pats[i], tok + 1))
 483                         return 0;
 484         }
 485         return 0;
 486 }
 487
 488 static int font_readgpos(struct font *fn, FILE *fin)
 489 {
 490         char tok[128];
 491         char *col;
 492         struct grule *rule;
 493         int feat, scrp, lang;
 494         int i, n;
 495         if (fscanf(fin, "%s %d", tok, &n) != 2)
 496                 return 1;
 497         font_readfeat(fn, tok, &feat, &scrp, &lang);
 498         rule = font_gpos(fn, n, feat, scrp, lang);
 499         for (i = 0; i < n; i++) {
 500                 if (fscanf(fin, "%s", tok) != 1)
 501                         return 1;
 502                 col = strchr(tok, ':');
 503                 if (col)
 504                         *col = '\0';
 505                 rule->pats[i].flg = GF_PAT;
 506                 if (!tok[0] || font_readgpat(fn, &rule->pats[i], tok))
 507                         return 0;
 508                 if (col)
 509                         sscanf(col + 1, "%hd%hd%hd%hd",
 510                                 &rule->pats[i].x, &rule->pats[i].y,
 511                                 &rule->pats[i].xadv, &rule->pats[i].yadv);
 512         }
 513         return 0;
 514 }
 515
 516 static int font_readggrp(struct font *fn, FILE *fin)
 517 {
 518         char tok[ILNLEN];
 519         int id, n, i, g;
 520         if (fscanf(fin, "%d %d", &id, &n) != 2)
 521                 return 1;
 522         for (i = 0; i < n; i++) {
 523                 if (fscanf(fin, "%s", tok) != 1)
 524                         return 1;
 525                 g = font_idx(fn, font_glyph(fn, tok));
 526                 if (g >= 0)
 527                         iset_put(fn->ggrp, id, g);
 528         }
 529         return 0;
 530 }
 531
 532 static int font_readkern(struct font *fn, FILE *fin)
 533 {
 534         char c1[ILNLEN], c2[ILNLEN];
 535         struct grule *rule;
 536         int val;
 537         if (fscanf(fin, "%s %s %d", c1, c2, &val) != 3)
 538                 return 1;
 539         rule = font_gpos(fn, 2, font_findfeat(fn, "kern"), -1, -1);
 540         rule->pats[0].g = font_idx(fn, font_glyph(fn, c1));
 541         rule->pats[1].g = font_idx(fn, font_glyph(fn, c2));
 542         rule->pats[0].xadv = val;
 543         rule->pats[0].flg = GF_PAT;
 544         rule->pats[1].flg = GF_PAT;
 545         return 0;
 546 }
 547
 548 static void font_lig(struct font *fn, char *lig)
 549 {
 550         char c[GNLEN];
 551         int g[WORDLEN];
 552         struct grule *rule;
 553         char *s = lig;
 554         int j, n = 0;
 555         while (utf8read(&s, c) > 0)
 556                 g[n++] = font_idx(fn, font_find(fn, c));
 557         rule = font_gsub(fn, n + 1, font_findfeat(fn, "liga"), -1, -1);
 558         for (j = 0; j < n; j++) {
 559                 rule->pats[j].g = g[j];
 560                 rule->pats[j].flg = GF_PAT;
 561         }
 562         rule->pats[n].g = font_idx(fn, font_find(fn, lig));
 563         rule->pats[n].flg = GF_REP;
 564 }
 565
 566 static void skipline(FILE* filp)
 567 {
 568         int c;
 569         do {
 570                 c = getc(filp);
 571         } while (c != '\n' && c != EOF);
 572 }
 573
 574 static struct gpat *font_rulefirstpat(struct font *fn, struct grule *rule)
 575 {
 576         int i;
 577         for (i = 0; i < rule->len; i++)
 578                 if (!(rule->pats[i].flg & (GF_REP | GF_CON)))
 579                         return &rule->pats[i];
 580         return NULL;
 581 }
 582
 583 static void font_isetinsert(struct font *fn, struct iset *iset, int rule, struct gpat *p)
 584 {
 585         if (p->flg & GF_GRP) {
 586                 int *r = iset_get(fn->ggrp, p->g);
 587                 while (r && *r >= 0)
 588                         iset_put(iset, *r++, rule);
 589         } else {
 590                 if (p->g >= 0)
 591                         iset_put(iset, p->g, rule);
 592         }
 593 }
 594
 595 struct font *font_open(char *path)
 596 {
 597         struct font *fn;
 598         int ch_g = -1;          /* last glyph in the charset */
 599         int ch_n = 0;                   /* number of glyphs in the charset */
 600         char tok[ILNLEN];
 601         FILE *fin;
 602         char ligs[512][GNLEN];
 603         int ligs_n = 0;
 604         int i;
 605         fin = fopen(path, "r");
 606         if (!fin)
 607                 return NULL;
 608         fn = xmalloc(sizeof(*fn));
 609         if (!fn) {
 610                 fclose(fin);
 611                 return NULL;
 612         }
 613         memset(fn, 0, sizeof(*fn));
 614         fn->gl_dict = dict_make(-1, 1, 0);
 615         fn->ch_dict = dict_make(-1, 1, 0);
 616         fn->ch_map = dict_make(-1, 1, 0);
 617         fn->ggrp = iset_make();
 618         while (fscanf(fin, "%s", tok) == 1) {
 619                 if (!strcmp("char", tok)) {
 620                         font_readchar(fn, fin, &ch_n, &ch_g);
 621                 } else if (!strcmp("kern", tok)) {
 622                         font_readkern(fn, fin);
 623                 } else if (!strcmp("ligatures", tok)) {
 624                         while (fscanf(fin, "%s", ligs[ligs_n]) == 1) {
 625                                 if (!strcmp("0", ligs[ligs_n]))
 626                                         break;
 627                                 if (ligs_n < LEN(ligs))
 628                                         ligs_n++;
 629                         }
 630                 } else if (!strcmp("gsub", tok)) {
 631                         font_readgsub(fn, fin);
 632                 } else if (!strcmp("gpos", tok)) {
 633                         font_readgpos(fn, fin);
 634                 } else if (!strcmp("ggrp", tok)) {
 635                         font_readggrp(fn, fin);
 636                 } else if (!strcmp("spacewidth", tok)) {
 637                         fscanf(fin, "%d", &fn->spacewid);
 638                 } else if (!strcmp("special", tok)) {
 639                         fn->special = 1;
 640                 } else if (!strcmp("name", tok)) {
 641                         fscanf(fin, "%s", fn->name);
 642                 } else if (!strcmp("fontname", tok)) {
 643                         fscanf(fin, "%s", fn->fontname);
 644                 } else if (!strcmp("charset", tok)) {
 645                         while (!font_readchar(fn, fin, &ch_n, &ch_g))
 646                                 ;
 647                         break;
 648                 }
 649                 skipline(fin);
 650         }
 651         for (i = 0; i < ligs_n; i++)
 652                 font_lig(fn, ligs[i]);
 653         fclose(fin);
 654         fn->gsub0 = iset_make();
 655         fn->gpos0 = iset_make();
 656         for (i = 0; i < fn->gsub_n; i++)
 657                 font_isetinsert(fn, fn->gsub0, i,
 658                         font_rulefirstpat(fn, &fn->gsub[i]));
 659         for (i = 0; i < fn->gpos_n; i++)
 660                 font_isetinsert(fn, fn->gpos0, i,
 661                         font_rulefirstpat(fn, &fn->gpos[i]));
 662         fn->scrp = -1;
 663         fn->lang = -1;
 664         return fn;
 665 }
 666
 667 void font_close(struct font *fn)
 668 {
 669         int i;
 670         for (i = 0; i < fn->gsub_n; i++)
 671                 free(fn->gsub[i].pats);
 672         for (i = 0; i < fn->gpos_n; i++)
 673                 free(fn->gpos[i].pats);
 674         dict_free(fn->gl_dict);
 675         dict_free(fn->ch_dict);
 676         dict_free(fn->ch_map);
 677         iset_free(fn->gsub0);
 678         iset_free(fn->gpos0);
 679         iset_free(fn->ggrp);
 680         free(fn->gsub);
 681         free(fn->gpos);
 682         free(fn->gl);
 683         free(fn);
 684 }
 685
 686 int font_special(struct font *fn)
 687 {
 688         return fn->special;
 689 }
 690
 691 /* return width w for the given font and size */
 692 int font_wid(struct font *fn, int sz, int w)
 693 {
 694         sz = font_zoom(fn, sz);
 695         return w >= 0 ? DEVWID(sz, w) : -DEVWID(sz, -w);
 696 }
 697
 698 /* return track kerning width for the given size */
 699 static int font_twid(struct font *fn, int sz)
 700 {
 701         if (fn->s1 >= 0 && sz <= fn->s1)
 702                 return fn->n1 * SC_PT;
 703         if (fn->s2 >= 0 && sz >= fn->s2)
 704                 return fn->n2 * SC_PT;
 705         if (sz > fn->s1 && sz < fn->s2)
 706                 return ((sz - fn->s1) * fn->n1 + (fn->s2 - sz) * fn->n2) *
 707                                 (long) SC_PT / (fn->s2 - fn->s1);
 708         return 0;
 709 }
 710
 711 /* glyph width, where cfn is the current font and fn is glyph's font */
 712 int font_gwid(struct font *fn, struct font *cfn, int sz, int w)
 713 {
 714         struct font *xfn = cfn ? cfn : fn;
 715         if (xfn->cs)
 716                 return xfn->cs * (font_zoom(fn, xfn->cs_ps ? xfn->cs_ps : sz)
 717                                         * SC_IN / 72) / 36;
 718         return font_wid(fn, sz, w) + (cfn ? font_twid(fn, sz) : 0) +
 719                 (font_getbd(xfn) ? font_getbd(xfn) - 1 : 0);
 720 }
 721
 722 /* space width for the give word space or sentence space */
 723 int font_swid(struct font *fn, int sz, int ss)
 724 {
 725         return font_gwid(fn, NULL, sz, (fn->spacewid * ss + 6) / 12);
 726 }
 727
 728 int font_getcs(struct font *fn)
 729 {
 730         return fn->cs;
 731 }
 732
 733 void font_setcs(struct font *fn, int cs, int ps)
 734 {
 735         fn->cs = cs;
 736         fn->cs_ps = ps;
 737 }
 738
 739 int font_getbd(struct font *fn)
 740 {
 741         return fn->bd;
 742 }
 743
 744 void font_setbd(struct font *fn, int bd)
 745 {
 746         fn->bd = bd;
 747 }
 748
 749 void font_track(struct font *fn, int s1, int n1, int s2, int n2)
 750 {
 751         fn->s1 = s1;
 752         fn->n1 = n1;
 753         fn->s2 = s2;
 754         fn->n2 = n2;
 755 }
 756
 757 int font_zoom(struct font *fn, int sz)
 758 {
 759         return fn->zoom ? (sz * fn->zoom + 500) / 1000 : sz;
 760 }
 761
 762 void font_setzoom(struct font *fn, int zoom)
 763 {
 764         fn->zoom = zoom;
 765 }
 766
 767 /* enable/disable font features; returns the previous value */
 768 int font_feat(struct font *fn, char *name, int val)
 769 {
 770         int idx = font_findfeat(fn, name);
 771         int old = idx >= 0 ? fn->feat_set[idx] : 0;
 772         if (idx >= 0)
 773                 fn->feat_set[idx] = val != 0;
 774         return old;
 775 }
 776
 777 /* set font script */
 778 void font_scrp(struct font *fn, char *name)
 779 {
 780         fn->scrp = name ? font_findscrp(fn, name) : -1;
 781 }
 782
 783 /* set font language */
 784 void font_lang(struct font *fn, char *name)
 785 {
 786         fn->lang = name ? font_findlang(fn, name) : -1;
 787 }