tfont.c - plan9port - [fork] Plan 9 from user space
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tfont.c (7635B)
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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 }