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