ref: f1e9b608a0529f3867cc78fd00952d924d424c0f
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)
#define GHASH(g1, g2) ((((g2) + 1) << 16) | ((g1) + 1))
#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 pattern for gsub and gpos tables; each grule has some gpats */
struct gpat {
short g; /* glyph index */
short flg; /* pattern flags; GF_* */
short x, y, xadv, yadv; /* gpos data */
};
/* glyph substitution and positioning rules */
struct grule {
struct gpat *pats;
short len; /* pats[] length */
short feat; /* feature owning this rule */
short pos; /* position of this rule in the file */
int hash; /* hash of this rule for sorting and comparison */
};
struct font {
char name[FNLEN];
char fontname[FNLEN];
int spacewid;
int special;
int cs, cs_ps, bd, zoom; /* for .cs, .bd, .fzoom requests */
struct glyph gl[NGLYPHS]; /* glyphs present in the font */
int gl_n; /* 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 */
char feat_name[NFEATS][8]; /* feature names */
int feat_set[NFEATS]; /* feature enabled */
int feat_n;
/* glyph substitution and positioning */
struct grule gsub[NGRULES]; /* glyph substitution rules */
int gsub_n;
struct grule gpos[NGRULES]; /* glyph positioning rules */
int gpos_n;
int *ggrp[NGRULES]; /* glyph groups */
int ggrp_len[NGRULES];
};
/* 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)
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 struct glyph *font_glyphput(struct font *fn, char *id, char *name, int type)
{
int i = fn->gl_n++;
struct glyph *g;
g = &fn->gl[i];
strcpy(g->id, id);
strcpy(g->name, name);
g->type = type;
g->font = fn;
dict_put(&fn->gl_dict, g->id, i);
return g;
}
/* 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;
}
/* 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;
}
/* compare their hashes, then their positions to make qsort() stable */
static int grulecmp(void *v1, void *v2)
{
struct grule *r1 = v1;
struct grule *r2 = v2;
return r1->hash == r2->hash ? r1->pos - r2->pos : r1->hash - r2->hash;
}
/* the hashing function for grule structs, based on their first two glyphs */
static int grule_hash(struct grule *rule)
{
int g1 = -1, g2 = -1;
int i = 0;
/* finding the first glyph; -1 if FG_GRP */
while (i < rule->len && rule->pats[i].flg & (GF_REP | GF_CON))
i++; /* skipping replacement and context glyphs */
if (i < rule->len && rule->pats[i].flg == GF_PAT)
g1 = rule->pats[i].g;
i++;
/* finding the second glyph; -1 if FG_GRP */
while (i < rule->len && rule->pats[i].flg & GF_REP)
i++; /* skipping replacement glyphs */
if (i < rule->len && rule->pats[i].flg == GF_PAT)
g2 = rule->pats[i].g;
return GHASH(g1, g2);
}
static int grule_find(struct grule *rules, int n, int hash)
{
int l = 0;
int h = n;
while (l < h) {
int m = (l + h) >> 1;
if (rules[m].hash >= hash)
h = m;
else
l = m + 1;
}
return l;
}
static int font_gpatmatch(struct font *fn, struct gpat *p, int g)
{
int i;
if (!(p->flg & GF_GRP))
return p->g == g;
for (i = 0; i < fn->ggrp_len[p->g]; i++)
if (fn->ggrp[p->g][i] == 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;
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;
}
/* 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;
int n = fn->gpos_n;
int i, j, k;
for (i = 0; i < slen; i++) {
/* possible hash values for matching gpos rules at src + slen */
for (j = 0; j < 4 && j < (slen << 1); j++) {
int hash = GHASH(j & 1 ? src[i] : -1, j & 2 ? src[i + 1] : -1);
int idx = grule_find(gpos, n, hash);
while (idx < n && gpos[idx].hash == hash) {
if (font_rulematch(fn, &gpos[idx],
src + i, slen - i, src + i, i)) {
struct gpat *pats = gpos[idx].pats;
/* we should accumulate the values... */
for (k = 0; k < gpos[idx].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;
}
}
idx++;
}
}
}
}
/* find the first gsub rule after pos that matches any glyph in src */
static struct grule *font_firstgsub(struct font *fn, int pos, int *src, int slen)
{
struct grule *rules = fn->gsub;
int n = fn->gsub_n;
struct grule *best = NULL;
int i, j;
for (i = 0; i < slen; i++) {
/* possible hash values for matching gsub rules at src + slen */
for (j = 0; j < 2 && i + j < slen; j++) {
int hash = GHASH(src[i], j ? src[i + 1] : -1);
int idx = grule_find(rules, n, hash);
while (idx < n && rules[idx].hash == hash &&
(!best || rules[idx].pos < best->pos)) {
if (rules[idx].pos >= pos)
if (font_rulematch(fn, &rules[idx],
src + i, slen - i, src + i, i))
best = &rules[idx];
idx++;
}
}
}
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++) {
int hash1 = GHASH(src[i], -1);
int hash2 = GHASH(src[i], i + 1 < slen ? src[i + 1] : -1);
int hmatch = rule->hash == hash1 || rule->hash == hash2;
dmap[dlen] = smap[i];
if (hmatch && 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 = 0;
while (i >= 0) {
struct grule *rule = font_firstgsub(fn, i, src, slen);
if (rule)
slen = font_gsubapply(fn, rule, src, slen, smap);
i = rule ? rule->pos + 1 : -1;
}
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, struct glyph **g)
{
char tok[ILNLEN];
char name[ILNLEN];
char id[ILNLEN];
int type;
if (*n + 1 == NGLYPHS)
errmsg("neatroff: NGLYPHS too low\n");
if (*n >= NGLYPHS)
return 0;
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;
*g = font_glyph(fn, id);
if (!*g) {
*g = font_glyphput(fn, id, name, type);
sscanf(tok, "%hd,%hd,%hd,%hd,%hd", &(*g)->wid,
&(*g)->llx, &(*g)->lly, &(*g)->urx, &(*g)->ury);
}
}
dict_put(&fn->ch_dict, name, *g - fn->gl);
(*n)++;
return 0;
}
static int font_findfeat(struct font *fn, char *feat, int mk)
{
int i;
for (i = 0; i < fn->feat_n; i++)
if (!strcmp(feat, fn->feat_name[i]))
return i;
if (mk)
strcpy(fn->feat_name[fn->feat_n], feat);
return mk ? fn->feat_n++ : -1;
}
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, char *feat, int len)
{
struct grule *rule;
struct gpat *pats = font_gpat(fn, len);
if (fn->gsub_n + 1 == LEN(fn->gsub))
errmsg("neatroff: NGRULES too low\n");
if (fn->gsub_n >= LEN(fn->gsub) || !pats)
return NULL;
rule = &fn->gsub[fn->gsub_n++];
rule->pats = pats;
rule->len = len;
rule->feat = font_findfeat(fn, feat, 1);
return rule;
}
static struct grule *font_gpos(struct font *fn, char *feat, int len)
{
struct grule *rule;
struct gpat *pats = font_gpat(fn, len);
if (fn->gpos_n + 1 == LEN(fn->gpos))
errmsg("neatroff: NGRULES too low\n");
if (fn->gpos_n >= LEN(fn->gpos) || !pats)
return NULL;
rule = &fn->gpos[fn->gpos_n++];
rule->pats = pats;
rule->len = len;
rule->feat = font_findfeat(fn, feat, 1);
return rule;
}
static int font_readgpat(struct font *fn, struct gpat *p, char *s)
{
if (s[0] == '@') {
p->g = atoi(s + 1);
if (fn->ggrp_len[p->g] == 1)
p->g = 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 int font_readgsub(struct font *fn, FILE *fin)
{
char tok[128];
struct grule *rule;
int i, n;
if (fscanf(fin, "%s %d", tok, &n) != 2)
return 1;
if (!(rule = font_gsub(fn, tok, n)))
return 0;
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 i, n;
if (fscanf(fin, "%s %d", tok, &n) != 2)
return 1;
if (!(rule = font_gpos(fn, tok, n)))
return 0;
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;
if (id >= LEN(fn->ggrp)) {
errmsg("neatroff: NGRULES too low\n");
return 0;
}
if (fn->ggrp[id])
free(fn->ggrp[id]);
fn->ggrp[id] = xmalloc(n * sizeof(fn->ggrp[id][0]));
fn->ggrp_len[id] = 0;
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)
fn->ggrp[id][fn->ggrp_len[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;
if (!(rule = font_gpos(fn, "kern", 2)))
return 0;
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));
if (!(rule = font_gsub(fn, "liga", n + 1)))
return;
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);
}
struct font *font_open(char *path)
{
struct font *fn;
struct glyph *ch_g = NULL; /* 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));
dict_init(&fn->gl_dict, NGLYPHS, -1, 0, 0);
dict_init(&fn->ch_dict, NGLYPHS, -1, 1, 0);
dict_init(&fn->ch_map, NGLYPHS, -1, 1, 0);
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("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);
for (i = 0; i < fn->gsub_n; i++)
fn->gsub[i].pos = i;
for (i = 0; i < fn->gpos_n; i++)
fn->gpos[i].pos = i;
for (i = 0; i < fn->gsub_n; i++)
fn->gsub[i].hash = grule_hash(&fn->gsub[i]);
for (i = 0; i < fn->gpos_n; i++)
fn->gpos[i].hash = grule_hash(&fn->gpos[i]);
qsort(fn->gsub, fn->gsub_n, sizeof(fn->gsub[0]), (void *) grulecmp);
qsort(fn->gpos, fn->gpos_n, sizeof(fn->gpos[0]), (void *) grulecmp);
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);
for (i = 0; i < LEN(fn->ggrp); i++)
free(fn->ggrp[i]);
dict_done(&fn->gl_dict);
dict_done(&fn->ch_dict);
dict_done(&fn->ch_map);
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);
}
/* 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)
{
if (cfn->cs)
return cfn->cs * (font_zoom(fn, cfn->cs_ps ? cfn->cs_ps : sz)
* SC_IN / 72) / 36;
return font_wid(fn, sz, w) + (font_getbd(cfn) ? font_getbd(cfn) - 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, fn, 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;
}
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, 0);
int old = idx >= 0 ? fn->feat_set[idx] : 0;
if (idx >= 0)
fn->feat_set[idx] = val != 0;
return old;
}