sys/src/libdraw/font.c

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