ref: 9a49e0b5cf0690cfe61ce0a390bb0c758d9e5b22
dir: /font.c/
/* font handling */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "roff.h"
/* convert wid in device unitwidth size to size sz */
#define DEVWID(sz, wid) (((wid) * (sz) + (dev_uwid / 2)) / dev_uwid)
/* flags for gpat->flg */
#define GF_PAT 1 /* gsub/gpos pattern glyph */
#define GF_REP 2 /* gsub replacement glyph */
#define GF_CON 4 /* context glyph */
#define GF_GRP 8 /* glyph group */
/* glyph substitution and positioning rules */
struct grule {
struct gpat { /* rule description */
int g; /* glyph index */
short flg; /* pattern flags; GF_* */
short x, y, xadv, yadv; /* gpos data */
} *pats; /* rule pattern */
int sec; /* rule section (OFF lookup) */
short len; /* pats[] length */
short feat, scrp, lang; /* rule's feature and script */
};
struct font {
char name[FNLEN];
char fontname[FNLEN];
int spacewid;
int special;
int cs, cs_ps, bd, zoom; /* for .cs, .bd, .fzoom requests */
int s1, n1, s2, n2; /* for .tkf request */
struct glyph *gl; /* glyphs present in the font */
int gl_n, gl_sz; /* number of glyphs in the font */
struct dict *gl_dict; /* mapping from gl[i].id to i */
struct dict *ch_dict; /* charset mapping */
struct dict *ch_map; /* characters mapped via font_map() */
/* font features and scripts */
char feat_name[NFEATS][8]; /* feature names */
int feat_set[NFEATS]; /* feature enabled */
char scrp_name[NSCRPS][8]; /* script names */
int scrp; /* current script */
char lang_name[NLANGS][8]; /* language names */
int lang; /* current language */
int secs; /* number of font sections (OFF lookups) */
/* glyph substitution and positioning */
struct grule *gsub; /* glyph substitution rules */
int gsub_n, gsub_sz;
struct grule *gpos; /* glyph positioning rules */
int gpos_n, gpos_sz;
struct iset *gsub0; /* rules matching a glyph at pos 0 */
struct iset *gpos0; /* rules matching a glyph at pos 0 */
struct iset *ggrp; /* glyph groups */
};
/* find a glyph by its name */
struct glyph *font_find(struct font *fn, char *name)
{
int i = dict_get(fn->ch_map, name);
if (i == -1) /* -2 means the glyph has been unmapped */
i = dict_get(fn->ch_dict, name);
return i >= 0 ? fn->gl + i : NULL;
}
/* find a glyph by its device-dependent identifier */
struct glyph *font_glyph(struct font *fn, char *id)
{
int i = dict_get(fn->gl_dict, id);
return i >= 0 ? &fn->gl[i] : NULL;
}
static int font_glyphput(struct font *fn, char *id, char *name, int type)
{
struct glyph *g;
if (fn->gl_n == fn->gl_sz) {
fn->gl_sz = fn->gl_sz + 1024;
fn->gl = mextend(fn->gl, fn->gl_n, fn->gl_sz, sizeof(fn->gl[0]));
}
g = &fn->gl[fn->gl_n];
snprintf(g->id, sizeof(g->id), "%s", id);
snprintf(g->name, sizeof(g->name), "%s", name);
g->type = type;
g->font = fn;
dict_put(fn->gl_dict, g->id, fn->gl_n);
return fn->gl_n++;
}
/* map character name to the given glyph; remove the mapping if id is NULL */
int font_map(struct font *fn, char *name, char *id)
{
int gidx = -1;
if (id)
gidx = font_glyph(fn, id) ? font_glyph(fn, id) - fn->gl : -2;
dict_put(fn->ch_map, name, gidx);
return 0;
}
/* return nonzero if character name has been mapped with font_map() */
int font_mapped(struct font *fn, char *name)
{
return dict_get(fn->ch_map, name) != -1;
}
static int font_findfeat(struct font *fn, char *feat);
/* enable/disable ligatures; first bit for liga and the second bit for rlig */
static int font_featlg(struct font *fn, int val)
{
int ret = 0;
ret |= font_feat(fn, "liga", val & 1);
ret |= font_feat(fn, "rlig", val & 2) << 1;
return ret;
}
/* enable/disable pairwise kerning */
static int font_featkn(struct font *fn, int val)
{
return font_feat(fn, "kern", val);
}
/* glyph index in fn->glyphs[] */
static int font_idx(struct font *fn, struct glyph *g)
{
return g ? g - fn->gl : -1;
}
static int font_gpatmatch(struct font *fn, struct gpat *p, int g)
{
int *r;
if (!(p->flg & GF_GRP))
return p->g == g;
r = iset_get(fn->ggrp, p->g);
while (r && *r >= 0)
if (*r++ == g)
return 1;
return 0;
}
static int font_rulematch(struct font *fn, struct grule *rule,
int *src, int slen, int *dst, int dlen)
{
int sidx = 0; /* the index of matched glyphs in src */
int ncon = 0; /* number of initial context glyphs */
struct gpat *pats = rule->pats;
int j;
/* enable only the active script if set */
if (fn->scrp >= 0 && fn->scrp != rule->scrp)
return 0;
/* enable common script features and those in the active language */
if (rule->lang >= 0 && fn->lang != rule->lang)
return 0;
if (!fn->feat_set[rule->feat])
return 0;
/* the number of initial context glyphs */
for (j = 0; j < rule->len && pats[j].flg & GF_CON; j++)
ncon++;
if (dlen < ncon)
return 0;
/* matching the base pattern */
for (; j < rule->len; j++) {
if (pats[j].flg & GF_REP)
continue;
if (sidx >= slen || !font_gpatmatch(fn, &pats[j], src[sidx]))
return 0;
sidx++;
}
/* matching the initial context */
for (j = 0; j < rule->len && pats[j].flg & GF_CON; j++)
if (!font_gpatmatch(fn, &pats[j], dst[j - ncon]))
return 0;
return 1;
}
/* find a matching gsub/gpos rule; *idx should be -1 initially */
static int font_findrule(struct font *fn, int gsub, int pos,
int *fwd, int fwdlen, int *ctx, int ctxlen, int *idx)
{
struct grule *rules = gsub ? fn->gsub : fn->gpos;
int *r1 = iset_get(gsub ? fn->gsub0 : fn->gpos0, fwd[0]);
while (r1 && r1[++*idx] >= 0) {
if (r1[*idx] >= pos && font_rulematch(fn, &rules[r1[*idx]],
fwd, fwdlen, ctx, ctxlen))
return r1[*idx];
}
return -1;
}
/* perform all possible gpos rules on src */
static void font_performgpos(struct font *fn, int *src, int slen,
int *x, int *y, int *xadv, int *yadv)
{
struct grule *gpos = fn->gpos;
struct gpat *pats;
int curs_feat = dir_do ? font_findfeat(fn, "curs") : -1;
int curs_beg = -1;
int curs_dif = 0;
int i, k;
for (i = 0; i < slen; i++) {
int idx = -1;
int curs_cur = 0;
int lastsec = -1;
while (1) {
int r = font_findrule(fn, 0, 0, src + i, slen - i,
src + i, i, &idx);
if (r < 0) /* no rule found */
break;
if (gpos[r].sec == lastsec) /* perform at most one rule from each lookup */
continue;
lastsec = gpos[r].sec;
pats = gpos[r].pats;
for (k = 0; k < gpos[r].len; k++) {
x[i + k] += pats[k].x;
y[i + k] += pats[k].y;
xadv[i + k] += pats[k].xadv;
yadv[i + k] += pats[k].yadv;
}
if (gpos[r].feat == curs_feat) {
curs_cur = 1;
if (curs_beg < 0)
curs_beg = i;
for (k = 0; k < gpos[r].len; k++)
curs_dif += pats[k].yadv;
}
}
if (curs_beg >= 0 && !curs_cur) {
yadv[curs_beg] -= curs_dif;
curs_beg = -1;
curs_dif = 0;
}
}
if (curs_beg >= 0)
yadv[curs_beg] -= curs_dif;
}
/* find the first gsub rule after pos that matches any glyph in src */
static int font_firstgsub(struct font *fn, int pos, int *src, int slen)
{
int best = -1;
int i;
for (i = 0; i < slen; i++) {
int idx = -1;
int r = font_findrule(fn, 1, pos, src + i, slen - i,
src + i, i, &idx);
if (r >= 0 && (best < 0 || r < best))
best = r;
}
return best;
}
/* apply the given gsub rule to all matches in src */
static int font_gsubapply(struct font *fn, struct grule *rule,
int *src, int slen, int *smap)
{
int dst[WORDLEN];
int dlen = 0;
int dmap[WORDLEN];
int i, j;
memset(dmap, 0, slen * sizeof(dmap[i]));
for (i = 0; i < slen; i++) {
dmap[dlen] = smap[i];
if (font_rulematch(fn, rule, src + i, slen - i,
dst + dlen, dlen)) {
for (j = 0; j < rule->len; j++) {
if (rule->pats[j].flg & GF_REP)
dst[dlen++] = rule->pats[j].g;
if (rule->pats[j].flg & GF_PAT)
i++;
}
i--;
} else {
dst[dlen++] = src[i];
}
}
memcpy(src, dst, dlen * sizeof(dst[0]));
memcpy(smap, dmap, dlen * sizeof(dmap[0]));
return dlen;
}
/* perform all possible gsub rules on src */
static int font_performgsub(struct font *fn, int *src, int slen, int *smap)
{
int i = -1;
while (++i >= 0) {
if ((i = font_firstgsub(fn, i, src, slen)) < 0)
break;
slen = font_gsubapply(fn, &fn->gsub[i], src, slen, smap);
}
return slen;
}
int font_layout(struct font *fn, struct glyph **gsrc, int nsrc, int sz,
struct glyph **gdst, int *dmap,
int *x, int *y, int *xadv, int *yadv, int lg, int kn)
{
int dst[WORDLEN];
int ndst = nsrc;
int i;
int featlg, featkn;
/* initialising dst */
for (i = 0; i < nsrc; i++)
dst[i] = font_idx(fn, gsrc[i]);
for (i = 0; i < ndst; i++)
dmap[i] = i;
memset(x, 0, ndst * sizeof(x[0]));
memset(y, 0, ndst * sizeof(y[0]));
memset(xadv, 0, ndst * sizeof(xadv[0]));
memset(yadv, 0, ndst * sizeof(yadv[0]));
/* substitution rules */
if (lg)
featlg = font_featlg(fn, 3);
ndst = font_performgsub(fn, dst, ndst, dmap);
if (lg)
font_featlg(fn, featlg);
/* positioning rules */
if (kn)
featkn = font_featkn(fn, 1);
font_performgpos(fn, dst, ndst, x, y, xadv, yadv);
if (kn)
font_featkn(fn, featkn);
for (i = 0; i < ndst; i++)
gdst[i] = fn->gl + dst[i];
return ndst;
}
static int font_readchar(struct font *fn, FILE *fin, int *n, int *gid)
{
struct glyph *g;
char tok[ILNLEN];
char name[ILNLEN];
char id[ILNLEN];
int type;
if (fscanf(fin, "%s %s", name, tok) != 2)
return 1;
if (!strcmp("---", name))
sprintf(name, "c%04d", *n);
if (strcmp("\"", tok)) {
if (fscanf(fin, "%d %s", &type, id) != 2)
return 1;
*gid = font_glyphput(fn, id, name, type);
g = &fn->gl[*gid];
sscanf(tok, "%hd,%hd,%hd,%hd,%hd", &g->wid,
&g->llx, &g->lly, &g->urx, &g->ury);
dict_put(fn->ch_dict, name, *gid);
(*n)++;
} else {
dict_put(fn->ch_map, name, *gid);
}
return 0;
}
static int font_findfeat(struct font *fn, char *feat)
{
int i;
for (i = 0; i < LEN(fn->feat_name) && fn->feat_name[i][0]; i++)
if (!strcmp(feat, fn->feat_name[i]))
return i;
if (i < LEN(fn->feat_name)) {
snprintf(fn->feat_name[i], sizeof(fn->feat_name[i]), "%s", feat);
return i;
}
return -1;
}
static int font_findscrp(struct font *fn, char *scrp)
{
int i;
for (i = 0; i < LEN(fn->scrp_name) && fn->scrp_name[i][0]; i++)
if (!strcmp(scrp, fn->scrp_name[i]))
return i;
if (i == LEN(fn->scrp_name))
return -1;
snprintf(fn->scrp_name[i], sizeof(fn->scrp_name[i]), "%s", scrp);
return i;
}
static int font_findlang(struct font *fn, char *lang)
{
int i;
for (i = 0; i < LEN(fn->lang_name) && fn->lang_name[i][0]; i++)
if (!strcmp(lang, fn->lang_name[i]))
return i;
if (i == LEN(fn->lang_name))
return -1;
snprintf(fn->lang_name[i], sizeof(fn->lang_name[i]), "%s", lang);
return i;
}
static struct gpat *font_gpat(struct font *fn, int len)
{
struct gpat *pats = xmalloc(len * sizeof(pats[0]));
memset(pats, 0, len * sizeof(pats[0]));
return pats;
}
static struct grule *font_gsub(struct font *fn, int len, int feat, int scrp, int lang)
{
struct grule *rule;
struct gpat *pats = font_gpat(fn, len);
if (fn->gsub_n == fn->gsub_sz) {
fn->gsub_sz = fn->gsub_sz + 1024;
fn->gsub = mextend(fn->gsub, fn->gsub_n, fn->gsub_sz,
sizeof(fn->gsub[0]));
}
rule = &fn->gsub[fn->gsub_n++];
rule->pats = pats;
rule->len = len;
rule->feat = feat;
rule->scrp = scrp;
rule->lang = lang;
return rule;
}
static struct grule *font_gpos(struct font *fn, int len, int feat, int scrp, int lang)
{
struct grule *rule;
struct gpat *pats = font_gpat(fn, len);
if (fn->gpos_n == fn->gpos_sz) {
fn->gpos_sz = fn->gpos_sz + 1024;
fn->gpos = mextend(fn->gpos, fn->gpos_n, fn->gpos_sz,
sizeof(fn->gpos[0]));
}
rule = &fn->gpos[fn->gpos_n++];
rule->pats = pats;
rule->len = len;
rule->feat = feat;
rule->scrp = scrp;
rule->lang = lang;
return rule;
}
static int font_readgpat(struct font *fn, struct gpat *p, char *s)
{
if (s[0] == '@') {
p->g = atoi(s + 1);
if (iset_len(fn->ggrp, p->g) == 1)
p->g = iset_get(fn->ggrp, p->g)[0];
else
p->flg |= GF_GRP;
} else {
p->g = font_idx(fn, font_glyph(fn, s));
}
return p->g < 0;
}
static void font_readfeat(struct font *fn, char *tok, int *feat, int *scrp, int *lang)
{
char *ftag = tok;
char *stag = NULL;
char *ltag = NULL;
*scrp = -1;
*lang = -1;
if (strchr(ftag, ':')) {
stag = strchr(ftag, ':') + 1;
stag[-1] = '\0';
}
if (strchr(stag, ':')) {
ltag = strchr(stag, ':') + 1;
ltag[-1] = '\0';
}
if (stag)
*scrp = font_findscrp(fn, stag);
if (ltag)
*lang = font_findlang(fn, ltag);
*feat = font_findfeat(fn, tok);
}
static int font_readgsub(struct font *fn, FILE *fin)
{
char tok[128];
struct grule *rule;
int feat, scrp, lang;
int i, n;
if (fscanf(fin, "%s %d", tok, &n) != 2)
return 1;
font_readfeat(fn, tok, &feat, &scrp, &lang);
rule = font_gsub(fn, n, feat, scrp, lang);
rule->sec = fn->secs;
for (i = 0; i < n; i++) {
if (fscanf(fin, "%s", tok) != 1)
return 1;
if (tok[0] == '-')
rule->pats[i].flg = GF_PAT;
if (tok[0] == '=')
rule->pats[i].flg = GF_CON;
if (tok[0] == '+')
rule->pats[i].flg = GF_REP;
if (!tok[0] || font_readgpat(fn, &rule->pats[i], tok + 1))
return 0;
}
return 0;
}
static int font_readgpos(struct font *fn, FILE *fin)
{
char tok[128];
char *col;
struct grule *rule;
int feat, scrp, lang;
int i, n;
if (fscanf(fin, "%s %d", tok, &n) != 2)
return 1;
font_readfeat(fn, tok, &feat, &scrp, &lang);
rule = font_gpos(fn, n, feat, scrp, lang);
rule->sec = fn->secs;
for (i = 0; i < n; i++) {
if (fscanf(fin, "%s", tok) != 1)
return 1;
col = strchr(tok, ':');
if (col)
*col = '\0';
rule->pats[i].flg = GF_PAT;
if (!tok[0] || font_readgpat(fn, &rule->pats[i], tok))
return 0;
if (col)
sscanf(col + 1, "%hd%hd%hd%hd",
&rule->pats[i].x, &rule->pats[i].y,
&rule->pats[i].xadv, &rule->pats[i].yadv);
}
return 0;
}
static int font_readggrp(struct font *fn, FILE *fin)
{
char tok[ILNLEN];
int id, n, i, g;
if (fscanf(fin, "%d %d", &id, &n) != 2)
return 1;
for (i = 0; i < n; i++) {
if (fscanf(fin, "%s", tok) != 1)
return 1;
g = font_idx(fn, font_glyph(fn, tok));
if (g >= 0)
iset_put(fn->ggrp, id, g);
}
return 0;
}
static int font_readkern(struct font *fn, FILE *fin)
{
char c1[ILNLEN], c2[ILNLEN];
struct grule *rule;
int val;
if (fscanf(fin, "%s %s %d", c1, c2, &val) != 3)
return 1;
rule = font_gpos(fn, 2, font_findfeat(fn, "kern"), -1, -1);
rule->pats[0].g = font_idx(fn, font_glyph(fn, c1));
rule->pats[1].g = font_idx(fn, font_glyph(fn, c2));
rule->pats[0].xadv = val;
rule->pats[0].flg = GF_PAT;
rule->pats[1].flg = GF_PAT;
return 0;
}
static void font_lig(struct font *fn, char *lig)
{
char c[GNLEN];
int g[WORDLEN];
struct grule *rule;
char *s = lig;
int j, n = 0;
while (utf8read(&s, c) > 0)
g[n++] = font_idx(fn, font_find(fn, c));
rule = font_gsub(fn, n + 1, font_findfeat(fn, "liga"), -1, -1);
for (j = 0; j < n; j++) {
rule->pats[j].g = g[j];
rule->pats[j].flg = GF_PAT;
}
rule->pats[n].g = font_idx(fn, font_find(fn, lig));
rule->pats[n].flg = GF_REP;
}
static void skipline(FILE* filp)
{
int c;
do {
c = getc(filp);
} while (c != '\n' && c != EOF);
}
static struct gpat *font_rulefirstpat(struct font *fn, struct grule *rule)
{
int i;
for (i = 0; i < rule->len; i++)
if (!(rule->pats[i].flg & (GF_REP | GF_CON)))
return &rule->pats[i];
return NULL;
}
static void font_isetinsert(struct font *fn, struct iset *iset, int rule, struct gpat *p)
{
if (p->flg & GF_GRP) {
int *r = iset_get(fn->ggrp, p->g);
while (r && *r >= 0)
iset_put(iset, *r++, rule);
} else {
if (p->g >= 0)
iset_put(iset, p->g, rule);
}
}
struct font *font_open(char *path)
{
struct font *fn;
int ch_g = -1; /* last glyph in the charset */
int ch_n = 0; /* number of glyphs in the charset */
char tok[ILNLEN];
FILE *fin;
char ligs[512][GNLEN];
int ligs_n = 0;
int i;
fin = fopen(path, "r");
if (!fin)
return NULL;
fn = xmalloc(sizeof(*fn));
if (!fn) {
fclose(fin);
return NULL;
}
memset(fn, 0, sizeof(*fn));
fn->gl_dict = dict_make(-1, 1, 0);
fn->ch_dict = dict_make(-1, 1, 0);
fn->ch_map = dict_make(-1, 1, 0);
fn->ggrp = iset_make();
while (fscanf(fin, "%s", tok) == 1) {
if (!strcmp("char", tok)) {
font_readchar(fn, fin, &ch_n, &ch_g);
} else if (!strcmp("kern", tok)) {
font_readkern(fn, fin);
} else if (!strcmp("ligatures", tok)) {
while (fscanf(fin, "%s", ligs[ligs_n]) == 1) {
if (!strcmp("0", ligs[ligs_n]))
break;
if (ligs_n < LEN(ligs))
ligs_n++;
}
} else if (!strcmp("gsec", tok)) {
fn->secs++;
} else if (!strcmp("gsub", tok)) {
font_readgsub(fn, fin);
} else if (!strcmp("gpos", tok)) {
font_readgpos(fn, fin);
} else if (!strcmp("ggrp", tok)) {
font_readggrp(fn, fin);
} else if (!strcmp("spacewidth", tok)) {
fscanf(fin, "%d", &fn->spacewid);
} else if (!strcmp("special", tok)) {
fn->special = 1;
} else if (!strcmp("name", tok)) {
fscanf(fin, "%s", fn->name);
} else if (!strcmp("fontname", tok)) {
fscanf(fin, "%s", fn->fontname);
} else if (!strcmp("charset", tok)) {
while (!font_readchar(fn, fin, &ch_n, &ch_g))
;
break;
}
skipline(fin);
}
for (i = 0; i < ligs_n; i++)
font_lig(fn, ligs[i]);
fclose(fin);
fn->gsub0 = iset_make();
fn->gpos0 = iset_make();
for (i = 0; i < fn->gsub_n; i++)
font_isetinsert(fn, fn->gsub0, i,
font_rulefirstpat(fn, &fn->gsub[i]));
for (i = 0; i < fn->gpos_n; i++)
font_isetinsert(fn, fn->gpos0, i,
font_rulefirstpat(fn, &fn->gpos[i]));
fn->scrp = -1;
fn->lang = -1;
return fn;
}
void font_close(struct font *fn)
{
int i;
for (i = 0; i < fn->gsub_n; i++)
free(fn->gsub[i].pats);
for (i = 0; i < fn->gpos_n; i++)
free(fn->gpos[i].pats);
dict_free(fn->gl_dict);
dict_free(fn->ch_dict);
dict_free(fn->ch_map);
iset_free(fn->gsub0);
iset_free(fn->gpos0);
iset_free(fn->ggrp);
free(fn->gsub);
free(fn->gpos);
free(fn->gl);
free(fn);
}
int font_special(struct font *fn)
{
return fn->special;
}
/* return width w for the given font and size */
int font_wid(struct font *fn, int sz, int w)
{
sz = font_zoom(fn, sz);
return w >= 0 ? DEVWID(sz, w) : -DEVWID(sz, -w);
}
/* return track kerning width for the given size */
static int font_twid(struct font *fn, int sz)
{
if (fn->s1 >= 0 && sz <= fn->s1)
return fn->n1 * SC_PT;
if (fn->s2 >= 0 && sz >= fn->s2)
return fn->n2 * SC_PT;
if (sz > fn->s1 && sz < fn->s2)
return ((sz - fn->s1) * fn->n1 + (fn->s2 - sz) * fn->n2) *
(long) SC_PT / (fn->s2 - fn->s1);
return 0;
}
/* glyph width, where cfn is the current font and fn is glyph's font */
int font_gwid(struct font *fn, struct font *cfn, int sz, int w)
{
struct font *xfn = cfn ? cfn : fn;
if (xfn->cs)
return xfn->cs * (font_zoom(fn, xfn->cs_ps ? xfn->cs_ps : sz)
* SC_IN / 72) / 36;
return font_wid(fn, sz, w) + (cfn ? font_twid(fn, sz) : 0) +
(font_getbd(xfn) ? font_getbd(xfn) - 1 : 0);
}
/* space width for the give word space or sentence space */
int font_swid(struct font *fn, int sz, int ss)
{
return font_gwid(fn, NULL, sz, (fn->spacewid * ss + 6) / 12);
}
int font_getcs(struct font *fn)
{
return fn->cs;
}
void font_setcs(struct font *fn, int cs, int ps)
{
fn->cs = cs;
fn->cs_ps = ps;
}
int font_getbd(struct font *fn)
{
return fn->bd;
}
void font_setbd(struct font *fn, int bd)
{
fn->bd = bd;
}
void font_track(struct font *fn, int s1, int n1, int s2, int n2)
{
fn->s1 = s1;
fn->n1 = n1;
fn->s2 = s2;
fn->n2 = n2;
}
int font_zoom(struct font *fn, int sz)
{
return fn->zoom ? (sz * fn->zoom + 500) / 1000 : sz;
}
void font_setzoom(struct font *fn, int zoom)
{
fn->zoom = zoom;
}
/* enable/disable font features; returns the previous value */
int font_feat(struct font *fn, char *name, int val)
{
int idx = font_findfeat(fn, name);
int old = idx >= 0 ? fn->feat_set[idx] : 0;
if (idx >= 0)
fn->feat_set[idx] = val != 0;
return old;
}
/* set font script */
void font_scrp(struct font *fn, char *name)
{
fn->scrp = name ? font_findscrp(fn, name) : -1;
}
/* set font language */
void font_lang(struct font *fn, char *name)
{
fn->lang = name ? font_findlang(fn, name) : -1;
}