backend/dvi/mdvi-lib/gf.c

   1 /* gf.c - GF font support */
   2 /*
   3  * Copyright (C) 2000, Matias Atria
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19
  20 /* functions to read GF fonts */
  21
  22 #include <string.h>
  23 #include "common.h"
  24 #include "mdvi.h"
  25 #include "private.h"
  26
  27 /* opcodes */
  28
  29 #define GF_PAINT0       0
  30 #define GF_PAINT1       64
  31 #define GF_PAINT2       65
  32 #define GF_PAINT3       66
  33 #define GF_BOC          67
  34 #define GF_BOC1         68
  35 #define GF_EOC          69
  36 #define GF_SKIP0        70
  37 #define GF_SKIP1        71
  38 #define GF_SKIP2        72
  39 #define GF_SKIP3        73
  40 #define GF_NEW_ROW_0    74
  41 #define GF_NEW_ROW_1    75
  42 #define GF_NEW_ROW_MAX  238
  43 #define GF_XXX1         239
  44 #define GF_XXX2         240
  45 #define GF_XXX3         241
  46 #define GF_XXX4         242
  47 #define GF_YYY          243
  48 #define GF_NOOP         244
  49 #define GF_LOC          245
  50 #define GF_LOC0         246
  51 #define GF_PRE          247
  52 #define GF_POST         248
  53 #define GF_POST_POST    249
  54
  55 #define GF_ID           131
  56 #define GF_TRAILER      223
  57
  58 #define BLACK 1
  59 #define WHITE 0
  60
  61 static int  gf_load_font __PROTO((DviParams *, DviFont *));
  62 static int  gf_font_get_glyph __PROTO((DviParams *, DviFont *, int));
  63
  64 /* only symbol exported by this file */
  65 DviFontInfo gf_font_info = {
  66         "GF",
  67         0, /* scaling not supported natively */
  68         gf_load_font,
  69         gf_font_get_glyph,
  70         mdvi_shrink_glyph,
  71         mdvi_shrink_glyph_grey,
  72         NULL,   /* free */
  73         NULL,   /* reset */
  74         NULL,   /* lookup */
  75         kpse_gf_format,
  76         NULL
  77 };
  78
  79 static int gf_read_bitmap(FILE *p, DviFontChar *ch)
  80 {
  81         int     op;
  82         int     min_n, max_n;
  83         int     min_m, max_m;
  84         int     paint_switch;
  85         int     x, y;
  86         int     bpl;
  87         Int32   par;
  88         BmUnit  *line;
  89         BITMAP  *map;
  90
  91         fseek(p, (long)ch->offset, SEEK_SET);
  92         op = fuget1(p);
  93         if(op == GF_BOC) {
  94                 /* skip character code */
  95                 fuget4(p);
  96                 /* skip pointer */
  97                 fuget4(p);
  98                 min_m = fsget4(p);
  99                 max_m = fsget4(p);
 100                 min_n = fsget4(p);
 101                 max_n = fsget4(p);
 102         } else if(op == GF_BOC1) {
 103                 /* skip character code */
 104                 fuget1(p);
 105                 min_m = fuget1(p); /* this is max_m - min_m */
 106                 max_m = fuget1(p);
 107                 min_n = fuget1(p); /* this is max_n - min_n */
 108                 max_n = fuget1(p);
 109                 min_m = max_m - min_m;
 110                 min_n = max_n - min_n;
 111         } else {
 112                 error(_("GF: invalid opcode %d in character %d\n"),
 113                         op, ch->code);
 114                 return -1;
 115         }
 116
 117         ch->x = -min_m;
 118         ch->y = max_n;
 119         ch->width = max_m - min_m + 1;
 120         ch->height = max_n - min_n + 1;
 121         map = bitmap_alloc(ch->width, ch->height);
 122
 123         ch->glyph.data = map;
 124         ch->glyph.x = ch->x;
 125         ch->glyph.y = ch->y;
 126         ch->glyph.w = ch->width;
 127         ch->glyph.h = ch->height;
 128
 129 #define COLOR(x)        ((x) ? "BLACK" : "WHITE")
 130
 131         paint_switch = WHITE;
 132         x = y = 0;
 133         line = map->data;
 134         bpl = map->stride;
 135         DEBUG((DBG_BITMAPS, "(gf) reading character %d\n", ch->code));
 136         while((op = fuget1(p)) != GF_EOC) {
 137                 Int32   n;
 138
 139                 if(feof(p))
 140                         break;
 141                 if(op == GF_PAINT0) {
 142                         DEBUG((DBG_BITMAPS, "(gf) Paint0 %s -> %s\n",
 143                                 COLOR(paint_switch), COLOR(!paint_switch)));
 144                         paint_switch = !paint_switch;
 145                 } else if(op <= GF_PAINT3) {
 146                         if(op < GF_PAINT1)
 147                                 par = op;
 148                         else
 149                                 par = fugetn(p, op - GF_PAINT1 + 1);
 150                         if(y >= ch->height || x + par >= ch->width)
 151                                 goto toobig;
 152                         /* paint everything between columns x and x + par - 1 */
 153                         DEBUG((DBG_BITMAPS, "(gf) Paint %d %s from (%d,%d)\n",
 154                                 par, COLOR(paint_switch), x, y));
 155                         if(paint_switch == BLACK)
 156                                 bitmap_paint_bits(line + (x / BITMAP_BITS),
 157                                         x % BITMAP_BITS, par);
 158                         paint_switch = !paint_switch;
 159                         x += par;
 160                 } else if(op >= GF_NEW_ROW_0 && op <= GF_NEW_ROW_MAX) {
 161                         y++;
 162                         line = bm_offset(line, bpl);
 163                         x = op - GF_NEW_ROW_0;
 164                         paint_switch = BLACK;
 165                         DEBUG((DBG_BITMAPS, "(gf) new_row_%d\n", x));
 166                 } else switch(op) {
 167                         case GF_SKIP0:
 168                                 y++;
 169                                 line = bm_offset(line, bpl);
 170                                 x = 0;
 171                                 paint_switch = WHITE;
 172                                 DEBUG((DBG_BITMAPS, "(gf) skip_0\n"));
 173                                 break;
 174                         case GF_SKIP1:
 175                         case GF_SKIP2:
 176                         case GF_SKIP3:
 177                                 par = fugetn(p, op - GF_SKIP1 + 1);
 178                                 y += par + 1;
 179                                 line = bm_offset(line, (par + 1) * bpl);
 180                                 x = 0;
 181                                 paint_switch = WHITE;
 182                                 DEBUG((DBG_BITMAPS, "(gf) skip_%d\n", op - GF_SKIP1));
 183                                 break;
 184                         case GF_XXX1:
 185                         case GF_XXX2:
 186                         case GF_XXX3:
 187                         case GF_XXX4: {
 188 #ifndef NODEBUG
 189                                 char    *s;
 190
 191                                 s = read_string(p, op - GF_XXX1 + 1, NULL, 0);
 192                                 DEBUG((DBG_SPECIAL, "(gf) Character %d: Special \"%s\"\n",
 193                                         ch->code, s));
 194                                 mdvi_free(s);
 195 #else
 196                                 n = fugetn(p, op - GF_XXX1 + 1);
 197                                 fseek(p, (long)n, SEEK_CUR);
 198 #endif
 199                                 break;
 200                         }
 201                         case GF_YYY:
 202                                 n = fuget4(p);
 203                                 DEBUG((DBG_SPECIAL, "(gf) Character %d: MF special %u\n",
 204                                         ch->code, n));
 205                                 break;
 206                         case GF_NOOP:
 207                                 DEBUG((DBG_BITMAPS, "(gf) no_op\n"));
 208                                 break;
 209                         default:
 210                                 error(_("(gf) Character %d: invalid opcode %d\n"),
 211                                         ch->code, op);
 212                                 goto error;
 213                 }
 214                 /* chech that we're still inside the bitmap */
 215                 if(x > ch->width || y > ch->height)
 216                         goto toobig;
 217                 DEBUG((DBG_BITMAPS, "(gf) curr_loc @ (%d,%d)\n", x, y));
 218         }
 219
 220         if(op != GF_EOC)
 221                 goto error;
 222         DEBUG((DBG_BITMAPS, "(gf) end of character %d\n", ch->code));
 223         return 0;
 224
 225 toobig:
 226         error(_("(gf) character %d has an incorrect bounding box\n"),
 227                 ch->code);
 228 error:
 229         bitmap_destroy(map);
 230         ch->glyph.data = NULL;
 231         return -1;
 232 }
 233
 234 static int gf_load_font(DviParams *unused, DviFont *font)
 235 {
 236         int     i;
 237         int     n;
 238         int     loc;
 239         int     hic;
 240         FILE    *p;
 241         Int32   word;
 242         int     op;
 243         long    alpha, beta, z;
 244 #ifndef NODEBUG
 245         char    s[256];
 246 #endif
 247
 248         p = font->in;
 249
 250         /* check preamble */
 251         loc = fuget1(p); hic = fuget1(p);
 252         if(loc != GF_PRE || hic != GF_ID)
 253                 goto badgf;
 254         loc = fuget1(p);
 255 #ifndef NODEBUG
 256         for(i = 0; i < loc; i++)
 257                 s[i] = fuget1(p);
 258         s[i] = 0;
 259         DEBUG((DBG_FONTS, "(gf) %s: %s\n", font->fontname, s));
 260 #else
 261         fseek(p, (long)loc, SEEK_CUR);
 262 #endif
 263         /* now read character locators in postamble */
 264         if(fseek(p, (long)-1, SEEK_END) == -1)
 265                 return -1;
 266
 267         n = 0;
 268         while((op = fuget1(p)) == GF_TRAILER) {
 269                 if(fseek(p, (long)-2, SEEK_CUR) < 0)
 270                         break;
 271                 n++;
 272         }
 273         if(op != GF_ID || n < 4)
 274                 goto badgf;
 275         /* get the pointer to the postamble */
 276         fseek(p, (long)-5, SEEK_CUR);
 277         op = fuget4(p);
 278         /* jump to it */
 279         fseek(p, (long)op, SEEK_SET);
 280         if(fuget1(p) != GF_POST)
 281                 goto badgf;
 282         /* skip pointer to last EOC */
 283         fuget4(p);
 284         /* get the design size */
 285         font->design = fuget4(p);
 286         /* the checksum */
 287         word = fuget4(p);
 288         if(word && font->checksum && font->checksum != word) {
 289                 warning(_("%s: bad checksum (expected %u, found %u)\n"),
 290                         font->fontname, font->checksum, word);
 291         } else if(!font->checksum)
 292                 font->checksum = word;
 293         /* skip pixels per point ratio */
 294         fuget4(p);
 295         fuget4(p);
 296         font->chars = xnalloc(DviFontChar, 256);
 297         for(loc = 0; loc < 256; loc++)
 298                 font->chars[loc].offset = 0;
 299         /* skip glyph "bounding box" */
 300         fseek(p, (long)16, SEEK_CUR);
 301         loc = 256;
 302         hic = -1;
 303         TFMPREPARE(font->scale, z, alpha, beta);
 304         while((op = fuget1(p)) != GF_POST_POST) {
 305                 DviFontChar *ch;
 306                 int     cc;
 307
 308                 /* get the character code */
 309                 cc = fuget1(p);
 310                 if(cc < loc)
 311                         loc = cc;
 312                 if(cc > hic)
 313                         hic = cc;
 314                 ch = &font->chars[cc];
 315                 switch(op) {
 316                 case GF_LOC:
 317                         fsget4(p); /* skip dx */
 318                         fsget4(p); /* skip dy */
 319                         break;
 320                 case GF_LOC0:
 321                         fuget1(p); /* skip dx */
 322                                    /* dy assumed 0 */
 323                         break;
 324                 default:
 325                         error(_("%s: junk in postamble\n"), font->fontname);
 326                         goto error;
 327                 }
 328                 ch->code = cc;
 329                 ch->tfmwidth = fuget4(p);
 330                 ch->tfmwidth = TFMSCALE(ch->tfmwidth, z, alpha, beta);
 331                 ch->offset = fuget4(p);
 332                 if(ch->offset == -1)
 333                         ch->offset = 0;
 334                 /* initialize the rest of the glyph information */
 335                 ch->x = 0;
 336                 ch->y = 0;
 337                 ch->width = 0;
 338                 ch->height = 0;
 339                 ch->glyph.data = NULL;
 340                 ch->shrunk.data = NULL;
 341                 ch->grey.data = NULL;
 342                 ch->flags = 0;
 343                 ch->loaded = 0;
 344         }
 345
 346         if(op != GF_POST_POST)
 347                 goto badgf;
 348
 349         if(loc > 0 || hic < 255) {
 350                 /* shrink to optimal size */
 351                 memmove(font->chars, font->chars + loc,
 352                         (hic - loc + 1) * sizeof(DviFontChar));
 353                 font->chars = xresize(font->chars,
 354                         DviFontChar, hic - loc + 1);
 355         }
 356         font->loc = loc;
 357         font->hic = hic;
 358
 359         return 0;
 360
 361 badgf:
 362         error(_("%s: File corrupted, or not a GF file\n"), font->fontname);
 363 error:
 364         if(font->chars) {
 365                 mdvi_free(font->chars);
 366                 font->chars = NULL;
 367         }
 368         font->loc = font->hic = 0;
 369         return -1;
 370 }
 371
 372 static int gf_font_get_glyph(DviParams *params, DviFont *font, int code)
 373 {
 374         DviFontChar     *ch;
 375
 376         if(code < font->loc || code > font->hic || !font->chars)
 377                 return -1;
 378         ch = &font->chars[code - font->loc];
 379
 380         if(!ch->loaded) {
 381                 if(ch->offset == 0)
 382                         return -1;
 383                 DEBUG((DBG_GLYPHS, "(gf) %s: loading GF glyph for character %d\n",
 384                         font->fontname, code));
 385                 if(font->in == NULL && font_reopen(font) < 0)
 386                         return -1;
 387                 if(fseek(font->in, ch->offset, SEEK_SET) == -1)
 388                         return -1;
 389                 if(gf_read_bitmap(font->in, ch) < 0)
 390                         return -1;
 391                 ch->loaded = 1;
 392         }
 393         return 0;
 394 }