ttf2png.c

   1 /*
   2 ttf2png - True Type Font to PNG converter
   3 Copyright (c) 2004-2008 Mikko Rasa
   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 #include <stdio.h>
  21 #include <ctype.h>
  22 #include <unistd.h>
  23 #include <getopt.h>
  24 #include <png.h>
  25 #include <ft2build.h>
  26 #include FT_FREETYPE_H
  27
  28 typedef struct sImage
  29 {
  30         unsigned w, h;
  31         char     *data;
  32 } Image;
  33
  34 typedef struct sGlyph
  35 {
  36         unsigned code;
  37         Image    image;
  38         unsigned x, y;
  39         int      offset_x;
  40         int      offset_y;
  41         int      advance;
  42 } Glyph;
  43
  44 typedef struct sFont
  45 {
  46         unsigned size;
  47         int      ascent;
  48         int      descent;
  49         unsigned n_glyphs;
  50         Glyph    *glyphs;
  51         Image    image;
  52 } Font;
  53
  54 unsigned round_to_pot(unsigned);
  55 void usage();
  56 void init_font(Font *, FT_Face, unsigned, unsigned, int);
  57 void render_grid(Font *, unsigned, unsigned, int);
  58 void render_packed(Font *);
  59 int save_defs(const char *, const Font *);
  60 int save_png(const char *, const Image *, char);
  61
  62 char verbose = 0;
  63
  64 int main(int argc, char **argv)
  65 {
  66         char *fn;
  67         int  begin = 0;
  68         int  end = 255;
  69         int  size = 10;
  70         int  cpl = 0;
  71         int  cell = 0;
  72         char autohinter = 0;
  73         char seq = 0;
  74         char alpha = 0;
  75         char pack = 0;
  76
  77         FT_Library freetype;
  78         FT_Face    face;
  79
  80         int  err;
  81         int  i;
  82
  83         char *out_fn = "font.png";
  84         char *def_fn = NULL;
  85
  86         Font font;
  87
  88         if(argc<2)
  89         {
  90                 usage();
  91                 return 1;
  92         }
  93
  94         while((i = getopt(argc, argv, "r:s:l:c:o:atvh?ed:p")) != -1)
  95         {
  96                 char *ptr;
  97                 int  temp;
  98                 switch(i)
  99                 {
 100                 case 'r':
 101                         if(!strcmp(optarg, "all"))
 102                         {
 103                                 begin = 0;
 104                                 end = 0x110000;
 105                         }
 106                         else
 107                         {
 108                                 if(!isdigit(optarg[0]))
 109                                         temp = -1;
 110                                 else
 111                                 {
 112                                         temp = strtol(optarg, &ptr, 0);
 113                                         if(ptr[0]!=',' || !isdigit(ptr[1]))
 114                                                 temp = -1;
 115                                 }
 116                                 if(temp<0)
 117                                 {
 118                                         printf("Not a valid range: %s\n", optarg);
 119                                         exit(1);
 120                                 }
 121                                 else
 122                                 {
 123                                         begin = temp;
 124                                         end = strtol(ptr+1, NULL, 0);
 125                                 }
 126                         }
 127                         break;
 128                 case 's':
 129                         size = strtol(optarg, NULL, 0);
 130                         break;
 131                 case 'l':
 132                         cpl = strtol(optarg, NULL, 0);
 133                         break;
 134                 case 'c':
 135                         cell = strtol(optarg, NULL, 0);
 136                         break;
 137                 case 'o':
 138                         out_fn = optarg;
 139                         break;
 140                 case 'a':
 141                         autohinter = 1;
 142                         break;
 143                 case 't':
 144                         alpha = 1;
 145                         break;
 146                 case 'v':
 147                         ++verbose;
 148                         break;
 149                 case 'h':
 150                 case '?':
 151                         usage();
 152                         return 0;
 153                 case 'e':
 154                         seq = 1;
 155                         break;
 156                 case 'd':
 157                         def_fn = optarg;
 158                         break;
 159                 case 'p':
 160                         pack = 1;
 161                         break;
 162                 }
 163         }
 164         if(!strcmp(out_fn, "-"))
 165                 verbose = 0;
 166
 167         if(optind!=argc-1)
 168         {
 169                 usage();
 170                 return 1;
 171         }
 172
 173         fn = argv[optind];
 174
 175         err = FT_Init_FreeType(&freetype);
 176         if(err)
 177         {
 178                 fprintf(stderr, "Couldn't initialize FreeType library\n");
 179                 return 1;
 180         }
 181
 182         err = FT_New_Face(freetype, fn, 0, &face);
 183         if(err)
 184         {
 185                 fprintf(stderr, "Couldn't load font file\n");
 186                 if(err==FT_Err_Unknown_File_Format)
 187                         fprintf(stderr, "Unknown file format\n");
 188                 return 1;
 189         }
 190
 191         if(verbose)
 192         {
 193                 const char *name = FT_Get_Postscript_Name(face);
 194                 printf("Font name: %s\n", name);
 195                 printf("Glyphs:    %ld\n", face->num_glyphs);
 196         }
 197
 198         err = FT_Set_Pixel_Sizes(face, 0, size);
 199         if(err)
 200         {
 201                 fprintf(stderr, "Couldn't set size\n");
 202                 return 1;
 203         }
 204
 205         font.size = size;
 206         init_font(&font, face, begin, end, autohinter);
 207         if(pack)
 208                 render_packed(&font);
 209         else
 210                 render_grid(&font, cell, cpl, seq);
 211         save_png(out_fn, &font.image, alpha);
 212         if(def_fn)
 213                 save_defs(def_fn, &font);
 214
 215         for(i=0; i<font.n_glyphs; ++i)
 216                 free(font.glyphs[i].image.data);
 217         free(font.glyphs);
 218         free(font.image.data);
 219
 220         FT_Done_Face(face);
 221         FT_Done_FreeType(freetype);
 222
 223         return 0;
 224 }
 225
 226 unsigned round_to_pot(unsigned n)
 227 {
 228         n -= 1;
 229         n |= n>>1;
 230         n |= n>>2;
 231         n |= n>>4;
 232         n |= n>>8;
 233         n |= n>>16;
 234
 235         return n+1;
 236 }
 237
 238 void usage()
 239 {
 240         printf("ttf2png - True Type Font to PNG converter\n"
 241                 "Copyright (c) 2004-2008  Mikko Rasa, Mikkosoft Productions\n"
 242                 "Distributed under the GNU General Public License\n\n"
 243                 "Usage: ttf2png [options] <TTF file>\n\n"
 244                 "Accepted options (default values in [brackets])\n"
 245                 "  -r  Range of characters to convert in the format low,high [0,255]\n"
 246                 "  -s  Font size to use, in pixels [10]\n"
 247                 "  -l  Number of characters to put in one line [auto]\n"
 248                 "  -c  Character cell size, in pixels [auto]\n"
 249                 "  -o  Output file name (or - for stdout) [font.png]\n"
 250                 "  -a  Force autohinter\n"
 251                 "  -t  Render font to alpha channel\n"
 252                 "  -v  Increase the level of verbosity\n"
 253                 "  -e  Use cells in sequence, rather than by code\n"
 254                 "  -p  Pack the glyphs tightly instead of in a grid\n"
 255                 "  -d  Write a definition to the given file\n"
 256                 "  -h  Print this message\n");
 257 }
 258
 259 void init_font(Font *font, FT_Face face, unsigned first, unsigned last, int autohinter)
 260 {
 261         unsigned i;
 262         unsigned size = 0;
 263
 264         font->ascent = (face->size->metrics.ascender+63)>>6;
 265         font->descent = (face->size->metrics.descender+63)>>6;
 266
 267         if(verbose>=1)
 268         {
 269                 printf("Ascent:    %d\n", font->ascent);
 270                 printf("Descent:   %d\n", font->descent);
 271         }
 272
 273         font->n_glyphs = 0;
 274         font->glyphs = NULL;
 275         for(i=first; i<=last; ++i)
 276         {
 277                 unsigned  n;
 278                 FT_Bitmap *bmp = &face->glyph->bitmap;
 279                 int       x, y;
 280                 int       flags = 0;
 281                 Glyph     *glyph;
 282
 283                 n = FT_Get_Char_Index(face, i);
 284                 if(!n)
 285                         continue;
 286
 287                 if(autohinter)
 288                         flags |= FT_LOAD_FORCE_AUTOHINT;
 289                 FT_Load_Glyph(face, n, flags);
 290                 FT_Render_Glyph(face->glyph, FT_RENDER_MODE_NORMAL);
 291
 292                 if(verbose>=2)
 293                         printf("  Char %u: glyph %u, size %dx%d\n", i, n, bmp->width, bmp->rows);
 294
 295                 if(bmp->pixel_mode!=FT_PIXEL_MODE_GRAY)
 296                 {
 297                         fprintf(stderr, "Warning: Glyph %u skipped, not grayscale\n", n);
 298                         continue;
 299                 }
 300
 301                 if(font->n_glyphs>=size)
 302                 {
 303                         size += 16;
 304                         font->glyphs = (Glyph *)realloc(font->glyphs, size*sizeof(Glyph));
 305                 }
 306
 307                 glyph = &font->glyphs[font->n_glyphs++];
 308                 glyph->code = i;
 309                 glyph->image.w = bmp->width;
 310                 glyph->image.h = bmp->rows;
 311                 glyph->image.data = (char *)malloc(bmp->width*bmp->rows);
 312                 glyph->offset_x = face->glyph->bitmap_left;
 313                 glyph->offset_y = face->glyph->bitmap_top-bmp->rows;
 314                 glyph->advance = (int)(face->glyph->advance.x+32)/64;
 315
 316                 if(bmp->pitch<0)
 317                 {
 318                         for(y=0; y<bmp->rows; ++y) for(x=0; x<bmp->width; ++x)
 319                                 glyph->image.data[x+(glyph->image.h-1-y)*glyph->image.w] = bmp->buffer[x-y*bmp->pitch];
 320                 }
 321                 else
 322                 {
 323                         for(y=0; y<bmp->rows; ++y) for(x=0; x<bmp->width; ++x)
 324                                 glyph->image.data[x+y*glyph->image.w] = bmp->buffer[x+y*bmp->pitch];
 325                 }
 326         }
 327
 328         if(verbose>=1)
 329                 printf("Loaded %u glyphs\n", font->n_glyphs);
 330 }
 331
 332 void render_grid(Font *font, unsigned cell, unsigned cpl, int seq)
 333 {
 334         unsigned i;
 335         int      top = 0, bot = 0;
 336         unsigned first, last;
 337         unsigned maxw = 0, maxh = 0;
 338
 339         for(i=1;; i<<=1)
 340         {
 341                 first = font->glyphs[0].code&~(i-1);
 342                 last = first+i-1;
 343                 if(last>=font->glyphs[font->n_glyphs-1].code)
 344                         break;
 345         }
 346
 347         for(i=0; i<font->n_glyphs; ++i)
 348         {
 349                 int y;
 350
 351                 y = font->glyphs[i].offset_y+font->glyphs[i].image.h;
 352                 if(y>top)
 353                         top = y;
 354                 if(font->glyphs[i].offset_y<bot)
 355                         bot = font->glyphs[i].offset_y;
 356                 if(font->glyphs[i].image.w>maxw)
 357                         maxw = font->glyphs[i].image.w;
 358                 if(font->glyphs[i].image.h>maxh)
 359                         maxh = font->glyphs[i].image.h;
 360         }
 361
 362         if(cell==0)
 363         {
 364                 cell = top-bot;
 365                 if(maxw>cell)
 366                         cell = maxw;
 367         }
 368
 369         if(verbose>=1)
 370         {
 371                 printf("Max size:  %u x %u\n", maxw, maxh);
 372                 printf("Y range:   [%d %d]\n", bot, top);
 373                 if(maxw>cell || top-bot>cell)
 374                         fprintf(stderr, "Warning: character size exceeds cell size (%d)\n", cell);
 375         }
 376
 377         if(cpl==0)
 378         {
 379                 unsigned count = (seq ? font->n_glyphs : last-first+1);
 380                 for(i=1;; i<<=1)
 381                 {
 382                         cpl = i/cell;
 383                         if(cpl>0 && (count+cpl-1)/cpl<=cpl)
 384                                 break;
 385                 }
 386         }
 387
 388         font->image.w = round_to_pot(cpl*cell);
 389         if(seq && font->n_glyphs<last-first+1)
 390                 font->image.h = (font->n_glyphs+cpl-1)/cpl*cell;
 391         else
 392                 font->image.h = (last-first+cpl)/cpl*cell;
 393         font->image.h = round_to_pot(font->image.h);
 394
 395         font->image.data = (char *)malloc(font->image.w*font->image.h);
 396         memset(font->image.data, 255, font->image.w*font->image.h);
 397
 398         for(i=0; i<font->n_glyphs; ++i)
 399         {
 400                 Glyph    *glyph;
 401                 int      cx, cy;
 402                 unsigned x, y;
 403
 404                 glyph = &font->glyphs[i];
 405
 406                 if(seq)
 407                 {
 408                         cx = (i%cpl)*cell;
 409                         cy = (i/cpl)*cell;
 410                 }
 411                 else
 412                 {
 413                         cx = ((glyph->code-first)%cpl)*cell;
 414                         cy = ((glyph->code-first)/cpl)*cell;
 415                 }
 416
 417                 if(cell>glyph->image.w)
 418                         cx += (cell-glyph->image.w)/2;
 419                 cy += top-glyph->offset_y-glyph->image.h;
 420
 421                 glyph->x = cx;
 422                 glyph->y = cy;
 423
 424                 for(y=0; y<glyph->image.h; ++y) for(x=0; x<glyph->image.w; ++x)
 425                 {
 426                         if(cx+x<0 || cx+x>=font->image.w || cy+y<0 || cy+y>=font->image.h)
 427                                 continue;
 428                         font->image.data[cx+x+(cy+y)*font->image.w] = 255-glyph->image.data[x+y*glyph->image.w];
 429                 }
 430         }
 431 }
 432
 433 void render_packed(Font *font)
 434 {
 435         unsigned i;
 436         unsigned area = 0;
 437         unsigned last_h = 0xFFFF;
 438         char     *used_glyphs;
 439         char     *used_pixels;
 440         unsigned cx = 0, cy;
 441
 442         for(i=0; i<font->n_glyphs; ++i)
 443                 area+=(font->glyphs[i].image.w+1)*(font->glyphs[i].image.h+1);
 444
 445         for(font->image.w=1;; font->image.w<<=1)
 446         {
 447                 font->image.h = (area*5/4)/font->image.w;
 448                 if(font->image.h<=font->image.w)
 449                         break;
 450         }
 451         font->image.h = round_to_pot(font->image.h);
 452
 453         font->image.data = (char *)malloc(font->image.w*font->image.h);
 454         memset(font->image.data, 255, font->image.w*font->image.h);
 455         used_pixels = (char *)malloc(font->image.w*font->image.h);
 456         memset(used_pixels, 0, font->image.w*font->image.h);
 457         used_glyphs = (char *)malloc(font->n_glyphs);
 458         memset(used_glyphs, 0, font->n_glyphs);
 459
 460         for(cy=0; cy<font->image.h;)
 461         {
 462                 unsigned w;
 463                 unsigned x, y;
 464                 Glyph    *glyph = NULL;
 465                 unsigned best_score = 0;
 466
 467                 for(; (cx<font->image.w && used_pixels[cx+cy*font->image.w]); ++cx) ;
 468                 if(cx>=font->image.w)
 469                 {
 470                         cx = 0;
 471                         ++cy;
 472                         last_h = 0xFFFF;
 473                         continue;
 474                 }
 475                 for(w=0; (cx+w<font->image.w && !used_pixels[cx+w+cy*font->image.w]); ++w) ;
 476
 477                 for(i=0; i<font->n_glyphs; ++i)
 478                 {
 479                         Glyph *g;
 480
 481                         g = &font->glyphs[i];
 482                         if(!used_glyphs[i] && g->image.w<=w)
 483                         {
 484                                 unsigned score;
 485
 486                                 score = g->image.h+1;
 487                                 if(g->image.h==last_h)
 488                                         score *= g->image.w;
 489                                 else
 490                                         score += g->image.w;
 491
 492                                 if(score>best_score)
 493                                 {
 494                                         glyph = g;
 495                                         best_score = score;
 496                                 }
 497                         }
 498                 }
 499
 500                 if(!glyph)
 501                 {
 502                         cx += w;
 503                         continue;
 504                 }
 505
 506                 used_glyphs[glyph-font->glyphs] = 1;
 507                 glyph->x = cx;
 508                 glyph->y = cy;
 509
 510                 for(y=0; y<glyph->image.h; ++y) for(x=0; x<glyph->image.w; ++x)
 511                 {
 512                         if(cx+x<0 || cx+x>=font->image.w || cy+y<0 || cy+y>=font->image.h)
 513                                 continue;
 514                         font->image.data[cx+x+(cy+y)*font->image.w] = 255-glyph->image.data[x+y*glyph->image.w];
 515                 }
 516                 for(y=0; y<glyph->image.h+2; ++y) for(x=0; x<glyph->image.w+2; ++x)
 517                 {
 518                         if(cx+x<1 || cx+x>font->image.w || cy+y<1 || cy+y>font->image.h)
 519                                 continue;
 520                         used_pixels[cx+x-1+(cy+y-1)*font->image.w] = 1;
 521                 }
 522
 523                 last_h = glyph->image.h;
 524         }
 525 }
 526
 527 int save_defs(const char *fn, const Font *font)
 528 {
 529         FILE     *out;
 530         unsigned i;
 531
 532         out = fopen(fn, "w");
 533         if(!out)
 534         {
 535                 fprintf(stderr, "Couldn't open %s\n",fn);
 536                 return -1;
 537         }
 538
 539         fprintf(out, "%d %d %d %d %d\n", font->image.w, font->image.h, font->size, font->ascent, font->descent);
 540         for(i=0; i<font->n_glyphs; ++i)
 541         {
 542                 const Glyph *g = &font->glyphs[i];
 543                 fprintf(out, "%u %u %u %u %u %d %d %d\n", g->code, g->x, g->y, g->image.w, g->image.h, g->offset_x, g->offset_y, g->advance);
 544         }
 545
 546         fclose(out);
 547
 548         return 0;
 549 }
 550
 551 int save_png(const char *fn, const Image *image, char alpha)
 552 {
 553         FILE       *out;
 554         png_struct *pngs;
 555         png_info   *pngi;
 556         png_byte   *rows[image->h];
 557         int        i;
 558         png_byte   *data2;
 559         int        color;
 560
 561         if(!strcmp(fn, "-"))
 562                 out = stdout;
 563         else
 564         {
 565                 out = fopen(fn, "wb");
 566                 if(!out)
 567                 {
 568                         fprintf(stderr, "Couldn't open %s\n",fn);
 569                         return -1;
 570                 }
 571         }
 572
 573         pngs = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
 574         if(!pngs)
 575         {
 576                 fprintf(stderr, "Error writing PNG file\n");
 577                 return -1;
 578         }
 579         pngi = png_create_info_struct(pngs);
 580         if(!pngi)
 581         {
 582                 png_destroy_write_struct(&pngs, NULL);
 583                 fprintf(stderr, "Error writing PNG file\n");
 584                 return -1;
 585         }
 586
 587         png_init_io(pngs, out);
 588         if(alpha)
 589         {
 590                 data2 = (png_byte *)malloc(image->w*image->h*2);
 591                 for(i=0; i<image->w*image->h; ++i)
 592                 {
 593                         data2[i*2] = 255;
 594                         data2[i*2+1] = 255-image->data[i];
 595                 }
 596                 for(i=0; i<image->h; ++i)
 597                         rows[i] = (png_byte *)(data2+i*image->w*2);
 598                 color = PNG_COLOR_TYPE_GRAY_ALPHA;
 599         }
 600         else
 601         {
 602                 for(i=0; i<image->h; ++i)
 603                         rows[i] = (png_byte *)(image->data+i*image->w);
 604                 color = PNG_COLOR_TYPE_GRAY;
 605         }
 606         png_set_IHDR(pngs, pngi, image->w, image->h, 8, color, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
 607         png_set_rows(pngs, pngi, rows);
 608         png_write_png(pngs, pngi, PNG_TRANSFORM_IDENTITY, NULL);
 609         png_destroy_write_struct(&pngs, &pngi);
 610         if(alpha)
 611                 free(data2);
 612
 613         if(verbose)
 614                 printf("Saved %dx%d PNG image to %s\n", image->w, image->h, fn);
 615
 616         fclose(out);
 617
 618         return 0;
 619 }