Initial revision

src/libdraw/font.c

@@ -0,0 +1,401 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+
+static int	fontresize(Font*, int, int, int);
+#if 0
+static int	freeup(Font*);
+#endif
+
+#define	PJW	0	/* use NUL==pjw for invisible characters */
+
+static Rune empty[] = { 0 };
+int
+cachechars(Font *f, char **ss, Rune **rr, ushort *cp, int max, int *wp, char **subfontname)
+{
+	int i, th, sh, h, ld, w, rw, wid, nc;
+	char *sp;
+	Rune r, *rp, vr;
+	ulong a;
+	Cacheinfo *c, *tc, *ec;
+
+	if(ss){
+		sp = *ss;
+		rp = empty;
+	}else{
+		sp = "";
+		rp = *rr;
+	}
+	wid = 0;
+	*subfontname = 0;
+	for(i=0; (*sp || *rp) && i<max; 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;
+		}
+
+		sh = (17 * (uint)r) & (f->ncache-NFLOOK-1);
+		c = &f->cache[sh];
+		ec = c+NFLOOK;
+		h = sh;
+		while(c < ec){
+			if(c->value==r && c->age)
+				goto Found;
+			c++;
+			h++;
+		}
+	
+		/*
+		 * Not found; toss out oldest entry
+		 */
+		a = ~0;
+		th = sh;
+		tc = &f->cache[th];
+		while(tc < ec){
+			if(tc->age < a){
+				a = tc->age;
+				h = th;
+				c = tc;
+			}
+			tc++;
+			th++;
+		}
+
+		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(c->age == f->age)	/* flush pending string output */
+			break;
+
+		ld = loadchar(f, r, c, h, i, subfontname);
+		if(ld <= 0){
+			if(ld == 0)
+				continue;
+			break;
+		}
+		c = &f->cache[h];	/* may have reallocated f->cache */
+	
+	    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(s->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){
+		depth = 0;
+		if(f->display){
+			if(f->display->screenimage)
+				depth = f->display->screenimage->depth;
+		}
+		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 = malloc((f->nsubf+DSUBF)*sizeof *subf);
+			if(f->subf == nil){
+				f->subf = of;
+				goto Toss;
+			}
+			memmove(f->subf, of, (f->nsubf+DSUBF)*sizeof *subf);
+			memset(f->subf+f->nsubf, 0, DSUBF*sizeof *subf);
+			subf = &f->subf[f->nsubf];
+			f->nsubf += DSUBF;
+			free(of);
+		}
+	}
+	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){
+		/* 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;
+
+	pic += cf->offset;
+	if(pic-cf->min >= subf->f->n)
+		goto TryPJW;
+	fi = &subf->f->info[pic - cf->min];
+	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){
+		/*
+		 * 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;
+		i = fontresize(f, f->width, f->ncache, f->maxdepth);
+		if(i <= 0)
+			return i;
+		/* c is still valid as didn't reallocate f->cache */
+	}
+	c->value = r;
+	top = fi->top + (f->ascent-subf->f->ascent);
+	bottom = fi->bottom + (f->ascent-subf->f->ascent);
+	c->width = fi->width;
+	c->x = h*f->width;
+	c->left = fi->left;
+	flushimage(f->display, 0);	/* flush any pending errors */
+	b = bufimage(f->display, 37);
+	if(b == 0)
+		return 0;
+	b[0] = 'l';
+	BPLONG(b+1, f->cacheimage->id);
+	BPLONG(b+5, subf->f->bits->id);
+	BPSHORT(b+9, c-f->cache);
+	BPLONG(b+11, c->x);
+	BPLONG(b+15, top);
+	BPLONG(b+19, c->x+((fi+1)->x-fi->x));
+	BPLONG(b+23, bottom);
+	BPLONG(b+27, fi->x);
+	BPLONG(b+31, fi->top);
+	b[35] = fi->left;
+	b[36] = fi->width;
+	return 1;
+}
+
+/* release all subfonts, return number freed */
+#if 0
+static
+int
+freeup(Font *f)
+{
+	Cachesubf *s, *es;
+	int nf;
+
+	if(f->sub[0]->name == nil)	/* font from mkfont; don't free */
+		return 0;
+	s = f->subf;
+	es = s+f->nsubf;
+	nf = 0;
+	while(s < es){
+		if(s->age){
+			freesubfont(s->f);
+			s->cf = nil;
+			s->f = nil;
+			s->age = 0;
+			nf++;
+		}
+		s++;
+	}
+	return nf;
+}
+#endif
+
+/* return 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;
+	d = f->display;
+	if(depth <= 0)
+		depth = 1;
+
+	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");
+		abort();
+		goto Return;
+	}
+	flushimage(d, 0);	/* flush any pending errors */
+	b = bufimage(d, 1+4+4+1);
+	if(b == 0){
+		freeimage(new);
+		goto Return;
+	}
+	b[0] = 'i';
+	BPLONG(b+1, new->id);
+	BPLONG(b+5, ncache);
+	b[9] = f->ascent;
+	if(flushimage(d, 0) < 0){
+		fprint(2, "resize: init failed: %r\n");
+		freeimage(new);
+		goto Return;
+	}
+	freeimage(f->cacheimage);
+	f->cacheimage = new;
+	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;
+}