ref: 704970074edd7280c8839ca3074e15c4dc07a1ac
dir: /sys/src/libdraw/font.c/
#include <u.h>
#include <libc.h>
#include <draw.h>
static int fontresize(Font*, int, int, int);
#define PJW 0 /* use NUL==pjw for invisible characters */
/* return number of translated cache indices, 0 must retry, -1 on error */
int
cachechars(Font *f, char **ss, Rune **rr, ushort *cp, int max, int *wp, char **subfontname)
{
int i, j, h, w, rw, wid, nc;
char *sp;
Rune r, *rp, vr;
ulong a;
Cacheinfo *c, *tc, *ec;
if(ss){
sp = *ss;
rp = L"";
}else{
sp = "";
rp = *rr;
}
wid = 0;
*subfontname = nil;
for(i=0; i<max && (*sp || *rp); sp+=w, rp+=rw){
if(ss){
r = *(uchar*)sp;
if(r < Runeself)
w = 1;
else{
w = chartorune(&vr, sp);
r = vr;
}
rw = 0;
}else{
r = *rp;
w = 0;
rw = 1;
}
a = ~0;
h = (17 * (uint)r) & (f->ncache-NFLOOK-1);
c = &f->cache[h];
tc = c;
ec = c+NFLOOK;
while(c < ec){
if(c->value==r && c->age)
goto Found;
if(c->age < a){
a = c->age;
tc = c;
}
c++;
h++;
}
/* Not found; use oldest entry */
c = tc;
h = tc - f->cache;
if(a && (f->age-a)<500){ /* kicking out too recent; resize */
nc = 2*(f->ncache-NFLOOK) + NFLOOK;
if(nc <= MAXFCACHE){
if(i == 0)
fontresize(f, f->width, nc, f->maxdepth);
/* else flush first; retry will resize */
break;
}
}
if(i > 0 && c->age == f->age) /* flush pending string output */
break;
j = loadchar(f, r, c, h, i, subfontname);
if(j <= 0){
if(j < 0 || i > 0) /* flush output or retry */
break;
return -1; /* stop retrying */
}
Found:
wid += c->width;
c->age = f->age;
cp[i] = h;
i++;
}
if(ss)
*ss = sp;
else
*rr = rp;
*wp = wid;
return i;
}
void
agefont(Font *f)
{
Cacheinfo *c, *ec;
Cachesubf *s, *es;
f->age++;
if(f->age == 65536){
/*
* Renormalize ages
*/
c = f->cache;
ec = c+f->ncache;
while(c < ec){
if(c->age){
c->age >>= 2;
c->age++;
}
c++;
}
s = f->subf;
es = s+f->nsubf;
while(s < es){
if(s->age){
if(s->age<SUBFAGE && s->cf->name != nil){
/* clean up */
if(f->display == nil || s->f != f->display->defaultsubfont)
freesubfont(s->f);
s->cf = nil;
s->f = nil;
s->age = 0;
}else{
s->age >>= 2;
s->age++;
}
}
s++;
}
f->age = (65536>>2) + 1;
}
}
static Subfont*
cf2subfont(Cachefont *cf, Font *f)
{
int depth;
char *name;
Subfont *sf;
name = cf->subfontname;
if(name == nil){
if(f->display != nil && f->display->screenimage != nil)
depth = f->display->screenimage->depth;
else
depth = 8;
name = subfontname(cf->name, f->name, depth);
if(name == nil)
return nil;
cf->subfontname = name;
}
sf = lookupsubfont(f->display, name);
return sf;
}
/* return 1 if load succeeded, 0 if failed, -1 if must retry */
int
loadchar(Font *f, Rune r, Cacheinfo *c, int h, int noflush, char **subfontname)
{
int i, oi, wid, top, bottom;
Rune pic;
Fontchar *fi;
Cachefont *cf;
Cachesubf *subf, *of;
uchar *b;
pic = r;
Again:
for(i=0; i<f->nsub; i++){
cf = f->sub[i];
if(cf->min<=pic && pic<=cf->max)
goto Found;
}
TryPJW:
if(pic != PJW){
pic = PJW;
goto Again;
}
return 0;
Found:
/*
* Choose exact or oldest
*/
oi = 0;
subf = &f->subf[0];
for(i=0; i<f->nsubf; i++){
if(cf == subf->cf)
goto Found2;
if(subf->age < f->subf[oi].age)
oi = i;
subf++;
}
subf = &f->subf[oi];
if(subf->f){
if(f->age-subf->age>SUBFAGE || f->nsubf>MAXSUBF){
Toss:
/* ancient data; toss */
freesubfont(subf->f);
subf->cf = nil;
subf->f = nil;
subf->age = 0;
}else{ /* too recent; grow instead */
of = f->subf;
f->subf = realloc(of, (f->nsubf+DSUBF)*sizeof *subf);
if(f->subf == nil){
f->subf = of;
goto Toss;
}
subf = &f->subf[f->nsubf];
memset(subf, 0, DSUBF*sizeof *subf);
f->nsubf += DSUBF;
}
}
subf->age = 0;
subf->cf = nil;
subf->f = cf2subfont(cf, f);
if(subf->f == nil){
if(cf->subfontname == nil)
goto TryPJW;
*subfontname = cf->subfontname;
return -1;
}
subf->cf = cf;
if(subf->f->ascent > f->ascent && f->display){
/* should print something? this is a mistake in the font file */
/* must prevent c->top from going negative when loading cache */
Image *b;
int d, t;
d = subf->f->ascent - f->ascent;
b = subf->f->bits;
draw(b, b->r, b, nil, addpt(b->r.min, Pt(0, d)));
draw(b, Rect(b->r.min.x, b->r.max.y-d, b->r.max.x, b->r.max.y), f->display->black, nil, b->r.min);
for(i=0; i<subf->f->n; i++){
t = subf->f->info[i].top-d;
if(t < 0)
t = 0;
subf->f->info[i].top = t;
t = subf->f->info[i].bottom-d;
if(t < 0)
t = 0;
subf->f->info[i].bottom = t;
}
subf->f->ascent = f->ascent;
}
Found2:
subf->age = f->age;
/* possible overflow here, but works out okay */
pic += cf->offset;
pic -= cf->min;
if(pic >= subf->f->n)
goto TryPJW;
fi = &subf->f->info[pic];
if(fi->width == 0)
goto TryPJW;
wid = (fi+1)->x - fi->x;
if(f->width < wid || f->width == 0 || f->maxdepth < subf->f->bits->depth
|| (f->display != nil && f->cacheimage == nil)){
/*
* Flush, free, reload (easier than reformatting f->b)
*/
if(noflush)
return -1;
if(f->width < wid)
f->width = wid;
if(f->maxdepth < subf->f->bits->depth)
f->maxdepth = subf->f->bits->depth;
if(fontresize(f, f->width, f->ncache, f->maxdepth) <= 0)
return -1;
/* c is still valid as didn't reallocate f->cache */
}
c->value = r;
c->width = fi->width;
c->x = h*f->width;
c->left = fi->left;
if(f->display == nil)
return 1;
b = bufimage(f->display, 37);
if(b == nil)
return 0;
top = fi->top + (f->ascent-subf->f->ascent);
bottom = fi->bottom + (f->ascent-subf->f->ascent);
b[0] = 'l';
BPLONG(b+1, f->cacheimage->id);
BPLONG(b+5, subf->f->bits->id);
BPSHORT(b+9, h);
BPLONG(b+11, c->x);
BPLONG(b+15, top);
BPLONG(b+19, c->x+wid);
BPLONG(b+23, bottom);
BPLONG(b+27, fi->x);
BPLONG(b+31, fi->top);
b[35] = fi->left;
b[36] = fi->width;
return 1;
}
/* returns whether resize succeeded && f->cache is unchanged */
static int
fontresize(Font *f, int wid, int ncache, int depth)
{
Cacheinfo *i;
int ret;
Image *new;
uchar *b;
Display *d;
ret = 0;
if(depth <= 0)
depth = 1;
if(wid <= 0)
wid = 1;
d = f->display;
if(d == nil)
goto Nodisplay;
new = allocimage(d, Rect(0, 0, ncache*wid, f->height), CHAN1(CGrey, depth), 0, 0);
if(new == nil){
fprint(2, "font cache resize failed: %r\n");
goto Return;
}
b = bufimage(d, 1+4+4+1);
if(b == nil){
freeimage(new);
goto Return;
}
b[0] = 'i';
BPLONG(b+1, new->id);
BPLONG(b+5, ncache);
b[9] = f->ascent;
freeimage(f->cacheimage);
f->cacheimage = new;
Nodisplay:
f->width = wid;
f->maxdepth = depth;
ret = 1;
if(f->ncache != ncache){
i = malloc(ncache*sizeof f->cache[0]);
if(i != nil){
ret = 0;
free(f->cache);
f->ncache = ncache;
f->cache = i;
}
/* else just wipe the cache clean and things will be ok */
}
Return:
memset(f->cache, 0, f->ncache*sizeof f->cache[0]);
return ret;
}