1 #include <u.h>
2 #include <libc.h>
3 #include <draw.h>
4 
5 static int	fontresize(Font*, int, int, int);
6 #if 0
7 static int	freeup(Font*);
8 #endif
9 
10 #define	PJW	0	/* use NUL==pjw for invisible characters */
11 
12 static Rune empty[] = { 0 };
13 int
14 cachechars(Font *f, char **ss, Rune **rr, ushort *cp, int max, int *wp, char **subfontname)
15 {
16 	int i, th, sh, h, ld, w, rw, wid, nc;
17 	char *sp;
18 	Rune r, *rp, vr;
19 	ulong a;
20 	Cacheinfo *c, *tc, *ec;
21 
22 	if(ss){
23 		sp = *ss;
24 		rp = empty;
25 	}else{
26 		sp = "";
27 		rp = *rr;
28 	}
29 	wid = 0;
30 	*subfontname = 0;
31 	for(i=0; i<max && (*sp || *rp); sp+=w, rp+=rw){
32 		if(ss){
33 			r = *(uchar*)sp;
34 			if(r < Runeself)
35 				w = 1;
36 			else{
37 				w = chartorune(&vr, sp);
38 				r = vr;
39 			}
40 			rw = 0;
41 		}else{
42 			r = *rp;
43 			w = 0;
44 			rw = 1;
45 		}
46 
47 		sh = (17 * (uint)r) & (f->ncache-NFLOOK-1);
48 		c = &f->cache[sh];
49 		ec = c+NFLOOK;
50 		h = sh;
51 		while(c < ec){
52 			if(c->value==r && c->age)
53 				goto Found;
54 			c++;
55 			h++;
56 		}
57 
58 		/*
59 		 * Not found; toss out oldest entry
60 		 */
61 		a = ~0;
62 		th = sh;
63 		tc = &f->cache[th];
64 		while(tc < ec){
65 			if(tc->age < a){
66 				a = tc->age;
67 				h = th;
68 				c = tc;
69 			}
70 			tc++;
71 			th++;
72 		}
73 
74 		if(a && (f->age-a)<500){	/* kicking out too recent; resize */
75 			nc = 2*(f->ncache-NFLOOK) + NFLOOK;
76 			if(nc <= MAXFCACHE){
77 				if(i == 0)
78 					fontresize(f, f->width, nc, f->maxdepth);
79 				/* else flush first; retry will resize */
80 				break;
81 			}
82 		}
83 
84 		if(c->age == f->age)	/* flush pending string output */
85 			break;
86 
87 		ld = loadchar(f, r, c, h, i, subfontname);
88 		if(ld <= 0){
89 			if(ld == 0)
90 				continue;
91 			break;
92 		}
93 		c = &f->cache[h];	/* may have reallocated f->cache */
94 
95 	    Found:
96 		wid += c->width;
97 		c->age = f->age;
98 		cp[i] = h;
99 		i++;
100 	}
101 	if(ss)
102 		*ss = sp;
103 	else
104 		*rr = rp;
105 	*wp = wid;
106 	return i;
107 }
108 
109 void
110 agefont(Font *f)
111 {
112 	Cacheinfo *c, *ec;
113 	Cachesubf *s, *es;
114 
115 	f->age++;
116 	if(f->age == 65536){
117 		/*
118 		 * Renormalize ages
119 		 */
120 		c = f->cache;
121 		ec = c+f->ncache;
122 		while(c < ec){
123 			if(c->age){
124 				c->age >>= 2;
125 				c->age++;
126 			}
127 			c++;
128 		}
129 		s = f->subf;
130 		es = s+f->nsubf;
131 		while(s < es){
132 			if(s->age){
133 				if(s->age<SUBFAGE && s->cf->name != nil){
134 					/* clean up */
135 					freesubfont(s->f);
136 					s->cf = nil;
137 					s->f = nil;
138 					s->age = 0;
139 				}else{
140 					s->age >>= 2;
141 					s->age++;
142 				}
143 			}
144 			s++;
145 		}
146 		f->age = (65536>>2) + 1;
147 	}
148 }
149 
150 static Subfont*
151 cf2subfont(Cachefont *cf, Font *f)
152 {
153 	int depth;
154 	char *name;
155 	Subfont *sf;
156 
157 	name = cf->subfontname;
158 	if(name == nil){
159 		depth = 0;
160 		if(f->display){
161 			if(f->display->screenimage)
162 				depth = f->display->screenimage->depth;
163 		}else
164 			depth = 8;
165 		name = subfontname(cf->name, f->name, depth);
166 		if(name == nil)
167 			return nil;
168 		cf->subfontname = name;
169 	}
170 	sf = lookupsubfont(f->display, name);
171 	return sf;
172 }
173 
174 /* return 1 if load succeeded, 0 if failed, -1 if must retry */
175 int
176 loadchar(Font *f, Rune r, Cacheinfo *c, int h, int noflush, char **subfontname)
177 {
178 	int i, oi, wid, top, bottom;
179 	int pic;	/* need >16 bits for adding offset below */
180 	Fontchar *fi;
181 	Cachefont *cf;
182 	Cachesubf *subf, *of;
183 	uchar *b;
184 
185 	pic = r;
186     Again:
187 	for(i=0; i<f->nsub; i++){
188 		cf = f->sub[i];
189 		if(cf->min<=pic && pic<=cf->max)
190 			goto Found;
191 	}
192     TryPJW:
193 	if(pic != PJW){
194 		pic = PJW;
195 		goto Again;
196 	}
197 	return 0;
198 
199     Found:
200 	/*
201 	 * Choose exact or oldest
202 	 */
203 	oi = 0;
204 	subf = &f->subf[0];
205 	for(i=0; i<f->nsubf; i++){
206 		if(cf == subf->cf)
207 			goto Found2;
208 		if(subf->age < f->subf[oi].age)
209 			oi = i;
210 		subf++;
211 	}
212 	subf = &f->subf[oi];
213 
214 	if(subf->f){
215 		if(f->age-subf->age>SUBFAGE || f->nsubf>MAXSUBF){
216     Toss:
217 			/* ancient data; toss */
218 			freesubfont(subf->f);
219 			subf->cf = nil;
220 			subf->f = nil;
221 			subf->age = 0;
222 		}else{				/* too recent; grow instead */
223 			of = f->subf;
224 			f->subf = realloc(of, (f->nsubf+DSUBF)*sizeof *subf);
225 			if(f->subf == nil){
226 				f->subf = of;
227 				goto Toss;
228 			}
229 			memset(f->subf+f->nsubf, 0, DSUBF*sizeof *subf);
230 			subf = &f->subf[f->nsubf];
231 			f->nsubf += DSUBF;
232 		}
233 	}
234 	subf->age = 0;
235 	subf->cf = nil;
236 	subf->f = cf2subfont(cf, f);
237 	if(subf->f == nil){
238 		if(cf->subfontname == nil)
239 			goto TryPJW;
240 		*subfontname = cf->subfontname;
241 		return -1;
242 	}
243 
244 	subf->cf = cf;
245 	if(subf->f->ascent > f->ascent && f->display){
246 		/* should print something? this is a mistake in the font file */
247 		/* must prevent c->top from going negative when loading cache */
248 		Image *b;
249 		int d, t;
250 		d = subf->f->ascent - f->ascent;
251 		b = subf->f->bits;
252 		draw(b, b->r, b, nil, addpt(b->r.min, Pt(0, d)));
253 		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);
254 		for(i=0; i<subf->f->n; i++){
255 			t = subf->f->info[i].top-d;
256 			if(t < 0)
257 				t = 0;
258 			subf->f->info[i].top = t;
259 			t = subf->f->info[i].bottom-d;
260 			if(t < 0)
261 				t = 0;
262 			subf->f->info[i].bottom = t;
263 		}
264 		subf->f->ascent = f->ascent;
265 	}
266 
267     Found2:
268 	subf->age = f->age;
269 
270 	/* possible overflow here, but works out okay */
271 	pic += cf->offset;
272 	pic -= cf->min;
273 	if(pic >= subf->f->n)
274 		goto TryPJW;
275 	fi = &subf->f->info[pic];
276 	if(fi->width == 0)
277 		goto TryPJW;
278 	wid = (fi+1)->x - fi->x;
279 	if(f->width < wid || f->width == 0 || f->maxdepth < subf->f->bits->depth){
280 		/*
281 		 * Flush, free, reload (easier than reformatting f->b)
282 		 */
283 		if(noflush)
284 			return -1;
285 		if(f->width < wid)
286 			f->width = wid;
287 		if(f->maxdepth < subf->f->bits->depth)
288 			f->maxdepth = subf->f->bits->depth;
289 		i = fontresize(f, f->width, f->ncache, f->maxdepth);
290 		if(i <= 0)
291 			return i;
292 		/* c is still valid as didn't reallocate f->cache */
293 	}
294 	c->value = r;
295 	top = fi->top + (f->ascent-subf->f->ascent);
296 	bottom = fi->bottom + (f->ascent-subf->f->ascent);
297 	c->width = fi->width;
298 	c->x = h*f->width;
299 	c->left = fi->left;
300 	if(f->display == nil)
301 		return 1;
302 	flushimage(f->display, 0);	/* flush any pending errors */
303 	b = bufimage(f->display, 37);
304 	if(b == 0)
305 		return 0;
306 	b[0] = 'l';
307 	BPLONG(b+1, f->cacheimage->id);
308 	BPLONG(b+5, subf->f->bits->id);
309 	BPSHORT(b+9, c-f->cache);
310 	BPLONG(b+11, c->x);
311 	BPLONG(b+15, top);
312 	BPLONG(b+19, c->x+((fi+1)->x-fi->x));
313 	BPLONG(b+23, bottom);
314 	BPLONG(b+27, fi->x);
315 	BPLONG(b+31, fi->top);
316 	b[35] = fi->left;
317 	b[36] = fi->width;
318 	return 1;
319 }
320 
321 /* release all subfonts, return number freed */
322 #if 0
323 static
324 int
325 freeup(Font *f)
326 {
327 	Cachesubf *s, *es;
328 	int nf;
329 
330 	if(f->sub[0]->name == nil)	/* font from mkfont; don't free */
331 		return 0;
332 	s = f->subf;
333 	es = s+f->nsubf;
334 	nf = 0;
335 	while(s < es){
336 		if(s->age){
337 			freesubfont(s->f);
338 			s->cf = nil;
339 			s->f = nil;
340 			s->age = 0;
341 			nf++;
342 		}
343 		s++;
344 	}
345 	return nf;
346 }
347 #endif
348 
349 /* return whether resize succeeded && f->cache is unchanged */
350 static int
351 fontresize(Font *f, int wid, int ncache, int depth)
352 {
353 	Cacheinfo *i;
354 	int ret;
355 	Image *new;
356 	uchar *b;
357 	Display *d;
358 
359 	ret = 0;
360 	if(depth <= 0)
361 		depth = 1;
362 
363 	d = f->display;
364 	if(d == nil)
365 		goto Nodisplay;
366 
367 	new = allocimage(d, Rect(0, 0, ncache*wid, f->height), CHAN1(CGrey, depth), 0, 0);
368 	if(new == nil){
369 		fprint(2, "font cache resize failed: %r\n");
370 		abort();
371 		goto Return;
372 	}
373 	flushimage(d, 0);	/* flush any pending errors */
374 	b = bufimage(d, 1+4+4+1);
375 	if(b == 0){
376 		freeimage(new);
377 		goto Return;
378 	}
379 	b[0] = 'i';
380 	BPLONG(b+1, new->id);
381 	BPLONG(b+5, ncache);
382 	b[9] = f->ascent;
383 	if(flushimage(d, 0) < 0){
384 		fprint(2, "resize: init failed: %r\n");
385 		freeimage(new);
386 		goto Return;
387 	}
388 	freeimage(f->cacheimage);
389 	f->cacheimage = new;
390     Nodisplay:
391 	f->width = wid;
392 	f->maxdepth = depth;
393 	ret = 1;
394 	if(f->ncache != ncache){
395 		i = malloc(ncache*sizeof f->cache[0]);
396 		if(i != nil){
397 			ret = 0;
398 			free(f->cache);
399 			f->ncache = ncache;
400 			f->cache = i;
401 		}
402 		/* else just wipe the cache clean and things will be ok */
403 	}
404     Return:
405 	memset(f->cache, 0, f->ncache*sizeof f->cache[0]);
406 	return ret;
407 }