ref: 43cd1d55e135a83bf803145c5bc2f7a9feb9d62e
dir: /font.c/
/* font handling */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "roff.h"
#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_ALT 8 /* glyph followed by alternative glyphs */
/* 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];
struct glyph glyphs[NGLYPHS];
int nglyphs;
int spacewid;
int special;
int cs, bd; /* for .cs and .bd requests */
struct dict gdict; /* mapping from glyphs[i].id to i */
/* charset section characters */
char c[NGLYPHS][GNLEN]; /* character names in charset */
struct glyph *g[NGLYPHS]; /* character glyphs in charset */
struct glyph *g_map[NGLYPHS]; /* character remapped via font_map() */
int n; /* number of characters in charset */
struct dict cdict; /* mapping from c[i] to i */
/* 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;
};
/* find a glyph by its name */
struct glyph *font_find(struct font *fn, char *name)
{
int i = dict_get(&fn->cdict, name);
if (i < 0)
return NULL;
return fn->g_map[i] ? fn->g_map[i] : fn->g[i];
}
/* find a glyph by its device-dependent identifier */
struct glyph *font_glyph(struct font *fn, char *id)
{
int i = dict_get(&fn->gdict, id);
return i >= 0 ? &fn->glyphs[i] : NULL;
}
static struct glyph *font_glyphput(struct font *fn, char *id, char *name, int type)
{
int i = fn->nglyphs++;
struct glyph *g;
g = &fn->glyphs[i];
strcpy(g->id, id);
strcpy(g->name, name);
g->type = type;
g->font = fn;
dict_put(&fn->gdict, g->id, i);
return g;
}
/* map character name to the given glyph */
int font_map(struct font *fn, char *name, struct glyph *g)
{
int i = dict_get(&fn->cdict, name);
if (g && g->font != fn)
return 1;
if (i < 0) {
if (fn->n >= NGLYPHS)
return 1;
i = fn->n++;
strcpy(fn->c[i], name);
dict_put(&fn->cdict, fn->c[i], i);
}
fn->g_map[i] = g;
return 0;
}
/* return nonzero if character name has been mapped with font_map() */
int font_mapped(struct font *fn, char *name)
{
int i = dict_get(&fn->cdict, name);
return i >= 0 && fn->g_map[i];
}
/* 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;
if (val & 1)
ret |= font_feat(fn, "liga", val);
if (val & 2)
ret |= font_feat(fn, "rlig", val) << 1;
return ret;
}
/* enable/disable pairwise kerning */
static int font_featkn(struct font *fn, int val)
{
return font_feat(fn, "kern", n_kn);
}
/* glyph index in fn->glyphs[] */
static int font_idx(struct font *fn, struct glyph *g)
{
return g ? g - fn->glyphs : -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 it matches more than one glyph */
while (i < rule->len && rule->pats[i].flg & (GF_REP | GF_CON))
i++; /* skipping replacement and context glyphs */
g1 = i < rule->len && rule->pats[i].flg == GF_PAT ? rule->pats[i].g : -1;
while (g1 < 0 && i < rule->len && rule->pats[i].flg & GF_ALT)
i++;
i++;
/* finding the second glyph; -1 if it matches more than one glyph */
while (i < rule->len && rule->pats[i].flg & GF_REP)
i++; /* skipping replacement glyphs */
g2 = i < rule->len && rule->pats[i].flg == GF_PAT ? rule->pats[i++].g : -1;
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 rules[l].hash == hash ? l : -1;
}
static int font_rulematches(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 didx = 0; /* the index of matched glyphs in dst */
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++)
if (pats[j].flg == GF_CON)
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 && pats[j].g == src[sidx]) {
sidx++;
while (pats[j].flg & GF_ALT)
j++;
} else if (!(pats[j].flg & GF_ALT)) {
return 0;
}
}
if (j != rule->len)
return 0;
/* matching the initial context */
for (j = 0; j < rule->len && pats[j].flg & GF_CON; j++) {
if (pats[j].g == dst[didx - ncon]) {
didx++;
while (pats[j].flg & GF_ALT)
j++;
} else if (!(pats[j].flg & GF_ALT)) {
return 0;
}
}
return 1;
}
static struct grule *font_findrule(struct font *fn, struct grule *rules, int n,
int *src, int slen, int *dst, int dlen)
{
int idx[4] = {-1, -1, -1, -1};
int hash[4];
int i, j;
for (j = 0; j < 4 && j < (slen << 1); j++) {
hash[j] = GHASH(j & 1 ? src[0] : -1, j & 2 ? src[1] : -1);
idx[j] = grule_find(rules, n, hash[j]);
}
while (1) {
i = -1; /* finding the first rule among idx[] */
for (j = 0; j < 4; j++)
if (idx[j] >= 0 && idx[j] < n && rules[idx[j]].hash == hash[j])
if (i < 0 || rules[idx[j]].pos <= rules[idx[i]].pos)
i = j;
if (i < 0)
break;
if (font_rulematches(fn, rules + idx[i], src, slen, dst, dlen))
return rules + idx[i];
idx[i]++;
}
return NULL;
}
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 src[WORDLEN], dst[WORDLEN];
int ndst = 0;
int i, j;
int featlg, featkn;
for (i = 0; i < nsrc; i++)
src[i] = font_idx(fn, gsrc[i]);
if (lg)
featlg = font_featlg(fn, 3);
for (i = 0; i < nsrc; i++) {
struct grule *rule = font_findrule(fn, fn->gsub, fn->gsub_n,
src + i, nsrc - i, dst + ndst, ndst);
dmap[ndst] = i;
if (rule) {
for (j = 0; j < rule->len; j++) {
if (rule->pats[j].flg == GF_REP)
dst[ndst++] = rule->pats[j].g;
if (rule->pats[j].flg == GF_PAT)
i++;
}
i--;
} else {
dst[ndst++] = src[i];
}
}
if (lg)
font_featlg(fn, featlg);
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]));
for (i = 0; i < ndst; i++)
gdst[i] = fn->glyphs + dst[i];
if (kn)
font_featkn(fn, 1);
for (i = 0; i < ndst; i++) {
int didx = i;
struct grule *rule = font_findrule(fn, fn->gpos, fn->gpos_n,
dst + i, ndst - i, dst + i, i);
if (!rule)
continue;
for (j = 0; j < rule->len; j++) {
if (rule->pats[j].g == dst[didx]) {
x[didx] = rule->pats[j].x;
y[didx] = rule->pats[j].y;
xadv[didx] = rule->pats[j].xadv;
yadv[didx] = rule->pats[j].yadv;
didx++;
while (rule->pats[j].flg & GF_ALT)
j++;
}
}
}
if (kn)
font_featkn(fn, featkn);
return ndst;
}
static int font_readchar(struct font *fn, FILE *fin)
{
char tok[ILNLEN];
char name[ILNLEN];
char id[ILNLEN];
struct glyph *glyph = NULL;
int type;
if (fn->n + 1 == NGLYPHS)
errmsg("neatroff: NGLYPHS too low\n");
if (fn->n >= NGLYPHS)
return 0;
if (fscanf(fin, "%s %s", name, tok) != 2)
return 1;
if (!strcmp("---", name))
sprintf(name, "c%04d", fn->n);
if (!strcmp("\"", tok)) {
glyph = fn->g[fn->n - 1];
} else {
if (fscanf(fin, "%d %s", &type, id) != 2)
return 1;
glyph = font_glyph(fn, id);
if (!glyph) {
glyph = font_glyphput(fn, id, name, type);
sscanf(tok, "%hd,%hd,%hd,%hd,%hd", &glyph->wid,
&glyph->llx, &glyph->lly,
&glyph->urx, &glyph->ury);
}
}
strcpy(fn->c[fn->n], name);
fn->g[fn->n] = glyph;
dict_put(&fn->cdict, fn->c[fn->n], fn->n);
fn->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_readgsub(struct font *fn, FILE *fin)
{
char tok[128];
struct grule *rule;
struct glyph *g;
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] || !(g = font_glyph(fn, tok + 1)))
return 0;
rule->pats[i].g = font_idx(fn, g);
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 (i > 0 && tok[0] == '|') {
rule->pats[i].flg = rule->pats[i - 1].flg;
rule->pats[i - 1].flg |= GF_ALT;
}
}
return 0;
}
static int font_readgpos(struct font *fn, FILE *fin)
{
char tok[128];
char *col;
struct grule *rule;
struct glyph *g;
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';
if (!(g = font_glyph(fn, tok + 1)))
return 0;
rule->pats[i].g = font_idx(fn, g);
rule->pats[i].flg = GF_PAT;
if (tok[0] == '|' && i > 0)
rule->pats[i - 1].flg |= GF_ALT;
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_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;
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->gdict, NGLYPHS, -1, 0, 0);
dict_init(&fn->cdict, NGLYPHS, -1, 0, 0);
while (fscanf(fin, "%s", tok) == 1) {
if (!strcmp("char", tok)) {
font_readchar(fn, fin);
} 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("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))
;
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);
dict_done(&fn->gdict);
dict_done(&fn->cdict);
free(fn);
}
int font_special(struct font *fn)
{
return fn->special;
}
int font_spacewid(struct font *fn)
{
return fn->spacewid;
}
int font_getcs(struct font *fn)
{
return fn->cs;
}
void font_setcs(struct font *fn, int cs)
{
fn->cs = cs;
}
int font_getbd(struct font *fn)
{
return fn->bd;
}
void font_setbd(struct font *fn, int bd)
{
fn->bd = bd;
}
/* 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;
}