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