src/freetype/cff/t2parse.c

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  t2parse.c                                                              */
   4 /*                                                                         */
   5 /*    OpenType parser (body).                                              */
   6 /*                                                                         */
   7 /*  Copyright 1996-2000 by                                                 */
   8 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
   9 /*                                                                         */
  10 /*  This file is part of the FreeType project, and may only be used,       */
  11 /*  modified, and distributed under the terms of the FreeType project      */
  12 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
  13 /*  this file you indicate that you have read the license and              */
  14 /*  understand and accept it fully.                                        */
  15 /*                                                                         */
  16 /***************************************************************************/
  17
  18
  19 #ifdef FT_FLAT_COMPILE
  20
  21 #include "t2parse.h"
  22
  23 #else
  24
  25 #include <cff/t2parse.h>
  26
  27 #endif
  28
  29
  30 #include <freetype/internal/t2errors.h>
  31
  32
  33   /*************************************************************************/
  34   /*                                                                       */
  35   /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
  36   /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
  37   /* messages during execution.                                            */
  38   /*                                                                       */
  39 #undef  FT_COMPONENT
  40 #define FT_COMPONENT  trace_t2parse
  41
  42
  43 #define T2_Err_Stack_Underflow   FT_Err_Invalid_Argument
  44 #define T2_Err_Syntax_Error      FT_Err_Invalid_Argument
  45
  46
  47   enum
  48   {
  49     t2_kind_none = 0,
  50     t2_kind_num,
  51     t2_kind_fixed,
  52     t2_kind_string,
  53     t2_kind_bool,
  54     t2_kind_delta,
  55     t2_kind_callback,
  56
  57     t2_kind_max  /* do not remove */
  58   };
  59
  60
  61   /* now generate handlers for the most simple fields */
  62   typedef FT_Error  (*T2_Field_Reader)( T2_Parser*  parser );
  63
  64   typedef struct  T2_Field_Handler_
  65   {
  66     int              kind;
  67     int              code;
  68     FT_UInt          offset;
  69     FT_Byte          size;
  70     T2_Field_Reader  reader;
  71     FT_UInt          array_max;
  72     FT_UInt          count_offset;
  73
  74   } T2_Field_Handler;
  75
  76
  77   LOCAL_FUNC
  78   void  T2_Parser_Init( T2_Parser*  parser,
  79                         FT_UInt     code,
  80                         void*       object )
  81   {
  82     MEM_Set( parser, 0, sizeof ( *parser ) );
  83
  84     parser->top         = parser->stack;
  85     parser->object_code = code;
  86     parser->object      = object;
  87   }
  88
  89
  90   /* reads an integer */
  91   static
  92   FT_Long  parse_t2_integer( FT_Byte*  start,
  93                              FT_Byte*  limit )
  94   {
  95     FT_Byte*  p   = start;
  96     FT_Int    v   = *p++;
  97     FT_Long   val = 0;
  98
  99
 100     if ( v == 28 )
 101     {
 102       if ( p + 2 > limit )
 103         goto Bad;
 104
 105       val = (FT_Short)( ( (FT_Int)p[0] << 8 ) | p[1] );
 106       p  += 2;
 107     }
 108     else if ( v == 29 )
 109     {
 110       if ( p + 4 > limit )
 111         goto Bad;
 112
 113       val = ( (FT_Long)p[0] << 24 ) |
 114             ( (FT_Long)p[1] << 16 ) |
 115             ( (FT_Long)p[2] <<  8 ) |
 116                        p[3];
 117       p += 4;
 118     }
 119     else if ( v < 247 )
 120     {
 121       val = v - 139;
 122     }
 123     else if ( v < 251 )
 124     {
 125       if ( p + 1 > limit )
 126         goto Bad;
 127
 128       val = ( v - 247 ) * 256 + p[0] + 108;
 129       p++;
 130     }
 131     else
 132     {
 133       if ( p + 1 > limit )
 134         goto Bad;
 135
 136       val = -( v - 251 ) * 256 - p[0] - 108;
 137       p++;
 138     }
 139
 140   Exit:
 141     return val;
 142
 143   Bad:
 144     val = 0;
 145     goto Exit;
 146   }
 147
 148
 149   /* read a real */
 150   static
 151   FT_Fixed  parse_t2_real( FT_Byte*  start,
 152                            FT_Byte*  limit,
 153                            FT_Int    power_ten )
 154   {
 155     FT_Byte*  p    = start;
 156     FT_Long   num, divider, result, exp;
 157     FT_Int    sign = 0, exp_sign = 0;
 158     FT_Byte   nib;
 159     FT_Byte   phase;
 160
 161
 162     result  = 0;
 163     num     = 0;
 164     divider = 1;
 165
 166     /* first of all, read the integer part */
 167     phase = 4;
 168     p--;
 169
 170     for (;;)
 171     {
 172       /* read one nibble at a time */
 173       if ( phase && ++p >= limit )
 174         goto Bad;
 175
 176       nib   = ( p[0] >> phase ) & 0xF;
 177       phase = 4 - phase;
 178
 179       if ( nib == 0xE )
 180         sign = 1;
 181       else if ( nib > 9 )
 182         break;
 183       else
 184         result = result * 10 + nib;
 185     }
 186
 187     /* read decimal part, if any */
 188     if ( nib == 0xa )
 189       for (;;)
 190       {
 191         /* read one nibble at a time */
 192         if ( !phase && ++p >= limit )
 193           goto Bad;
 194
 195         phase = 4 - phase;
 196         nib   = ( p[0] >> phase ) & 0xF;
 197
 198         if ( nib >= 10 )
 199           break;
 200
 201         if (divider < 10000000L)
 202         {
 203           num      = num * 10 + nib;
 204           divider *= 10;
 205         }
 206       }
 207
 208     /* read exponent, if any */
 209     if ( nib == 12 )
 210     {
 211       exp_sign = 1;
 212       nib      = 11;
 213     }
 214
 215     if ( nib == 11 )
 216     {
 217       exp = 0;
 218
 219       for (;;)
 220       {
 221         /* read one nibble at a time */
 222         if ( !phase && ++p >= limit )
 223           goto Bad;
 224
 225         phase = 4 - phase;
 226         nib   = ( p[0] >> phase ) & 0xF;
 227
 228         if ( nib >= 10 )
 229           break;
 230
 231         exp = exp * 10 + nib;
 232       }
 233
 234       if ( exp_sign )
 235         exp = -exp;
 236
 237       power_ten += exp;
 238     }
 239
 240     /* raise to power of ten if needed */
 241     while ( power_ten > 0 )
 242     {
 243       result = result * 10;
 244       num    = num * 10;
 245
 246       power_ten--;
 247     }
 248
 249     while ( power_ten < 0 )
 250     {
 251       result  = result / 10;
 252       divider = divider * 10;
 253
 254       power_ten++;
 255     }
 256
 257     if ( num )
 258       result += FT_DivFix( num, divider );
 259
 260     if ( sign )
 261       result = -result;
 262
 263   Exit:
 264     return result;
 265
 266   Bad:
 267     result = 0;
 268     goto Exit;
 269   }
 270
 271
 272   /* read a number, either integer or real */
 273   static
 274   FT_Long  t2_parse_num( FT_Byte**  d )
 275   {
 276     return ( **d == 30 ? ( parse_t2_real( d[0], d[1], 0 ) >> 16 )
 277                        : parse_t2_integer( d[0], d[1] ) );
 278   }
 279
 280
 281   /* reads a floating point number, either integer or real */
 282   static
 283   FT_Fixed  t2_parse_fixed( FT_Byte**  d )
 284   {
 285     return ( **d == 30 ? parse_t2_real( d[0], d[1], 0 )
 286                        : parse_t2_integer( d[0], d[1] ) << 16 );
 287   }
 288
 289
 290   static
 291   FT_Error  parse_font_matrix( T2_Parser*  parser )
 292   {
 293     CFF_Font_Dict*  dict   = (CFF_Font_Dict*)parser->object;
 294     FT_Matrix*      matrix = &dict->font_matrix;
 295     FT_Byte**       data   = parser->stack;
 296     FT_Error        error;
 297
 298
 299     error = T2_Err_Stack_Underflow;
 300
 301     if ( parser->top >= parser->stack + 4 )
 302     {
 303       matrix->xx = t2_parse_fixed( data++ );
 304       matrix->yx = t2_parse_fixed( data++ );
 305       matrix->xy = t2_parse_fixed( data++ );
 306       matrix->yy = t2_parse_fixed( data   );
 307       error = T2_Err_Ok;
 308     }
 309
 310     return error;
 311   }
 312
 313
 314   static
 315   FT_Error  parse_font_bbox( T2_Parser*  parser )
 316   {
 317     CFF_Font_Dict*  dict = (CFF_Font_Dict*)parser->object;
 318     FT_BBox*        bbox = &dict->font_bbox;
 319     FT_Byte**       data = parser->stack;
 320     FT_Error        error;
 321
 322
 323     error = T2_Err_Stack_Underflow;
 324
 325     if ( parser->top >= parser->stack + 4 )
 326     {
 327       bbox->xMin = t2_parse_num( data++ );
 328       bbox->yMin = t2_parse_num( data++ );
 329       bbox->xMax = t2_parse_num( data++ );
 330       bbox->yMax = t2_parse_num( data   );
 331       error = T2_Err_Ok;
 332     }
 333
 334     return error;
 335   }
 336
 337
 338   static
 339   FT_Error  parse_private_dict( T2_Parser*  parser )
 340   {
 341     CFF_Font_Dict*  dict = (CFF_Font_Dict*)parser->object;
 342     FT_Byte**       data = parser->stack;
 343     FT_Error        error;
 344
 345
 346     error = T2_Err_Stack_Underflow;
 347
 348     if ( parser->top >= parser->stack + 2 )
 349     {
 350       dict->private_size   = t2_parse_num( data++ );
 351       dict->private_offset = t2_parse_num( data   );
 352       error = T2_Err_Ok;
 353     }
 354
 355     return error;
 356   }
 357
 358
 359   static
 360   FT_Error  parse_cid_ros( T2_Parser*  parser )
 361   {
 362     CFF_Font_Dict*  dict   = (CFF_Font_Dict*)parser->object;
 363     FT_Byte**       data   = parser->stack;
 364     FT_Error        error;
 365
 366
 367     error = T2_Err_Stack_Underflow;
 368
 369     if ( parser->top >= parser->stack + 3 )
 370     {
 371       dict->cid_registry   = (FT_UInt)t2_parse_num( data++ );
 372       dict->cid_ordering   = (FT_UInt)t2_parse_num( data++ );
 373       dict->cid_supplement = (FT_ULong)t2_parse_num( data );
 374       error = T2_Err_Ok;
 375     }
 376
 377     return error;
 378   }
 379
 380
 381 #define T2_FIELD_NUM( code, name ) \
 382           T2_FIELD( code, name, t2_kind_num )
 383 #define T2_FIELD_FIXED( code, name ) \
 384           T2_FIELD( code, name, t2_kind_fixed )
 385 #define T2_FIELD_STRING( code, name ) \
 386           T2_FIELD( code, name, t2_kind_string )
 387 #define T2_FIELD_BOOL( code, name ) \
 388           T2_FIELD( code, name, t2_kind_bool )
 389 #define T2_FIELD_DELTA( code, name,max ) \
 390           T2_FIELD( code, name, t2_kind_delta )
 391
 392 #define T2_REF( s, f )  ( ((s*)0)->f )
 393
 394 #define T2_FIELD_CALLBACK( code, name ) \
 395           {                             \
 396             t2_kind_callback,           \
 397             code | T2CODE,              \
 398             0, 0,                       \
 399             parse_ ## name,             \
 400             0, 0                        \
 401           },
 402
 403 #undef  T2_FIELD
 404 #define T2_FIELD( code, name, kind )                 \
 405           {                                          \
 406             kind,                                    \
 407             code | T2CODE,                           \
 408             (FT_UInt)(char*)&T2_REF( T2TYPE, name ), \
 409             sizeof( T2_REF( T2TYPE, name ) ),        \
 410             0, 0, 0                                  \
 411           },
 412
 413 #undef  T2_FIELD_DELTA
 414 #define T2_FIELD_DELTA( code, name, max )                    \
 415         {                                                    \
 416           t2_kind_delta,                                     \
 417           code | T2CODE,                                     \
 418           (FT_UInt)(char*)&T2_REF( T2TYPE, name ),           \
 419           sizeof( T2_REF( T2TYPE, name )[0] ),               \
 420           0,                                                 \
 421           max,                                               \
 422           (FT_UInt)(char*)&T2_REF( T2TYPE, num_ ## name )    \
 423         },
 424
 425 #define T2CODE_TOPDICT  0x1000
 426 #define T2CODE_PRIVATE  0x2000
 427
 428   static const T2_Field_Handler  t2_field_handlers[] =
 429   {
 430
 431 #ifdef FT_FLAT_COMPILE
 432
 433 #include "t2tokens.h"
 434
 435 #else
 436
 437 #include <cff/t2tokens.h>
 438
 439 #endif
 440
 441     { 0, 0, 0, 0, 0, 0, 0 }
 442   };
 443
 444
 445   LOCAL_FUNC
 446   FT_Error  T2_Parser_Run( T2_Parser*  parser,
 447                            FT_Byte*    start,
 448                            FT_Byte*    limit )
 449   {
 450     FT_Byte*  p     = start;
 451     FT_Error  error = T2_Err_Ok;
 452
 453
 454     parser->top    = parser->stack;
 455     parser->start  = start;
 456     parser->limit  = limit;
 457     parser->cursor = start;
 458
 459     while ( p < limit )
 460     {
 461       FT_Byte  v = *p;
 462
 463
 464       if ( v >= 27 && v != 31 )
 465       {
 466         /* it's a number; we will push its position on the stack */
 467         if ( parser->top - parser->stack >= T2_MAX_STACK_DEPTH )
 468           goto Stack_Overflow;
 469
 470         *parser->top ++ = p;
 471
 472         /* now, skip it */
 473         if ( v == 30 )
 474         {
 475           /* skip real number */
 476           for (;;)
 477           {
 478             if ( p >= limit )
 479               goto Syntax_Error;
 480             v = p[0] >> 4;
 481             if ( v == 15 )
 482               break;
 483             v = p[0] & 0xF;
 484             if ( v == 15 )
 485               break;
 486             p++;
 487           }
 488           p++;
 489         }
 490         else if ( v == 28 )
 491           p += 2;
 492         else if ( v == 29 )
 493           p += 4;
 494         else if ( v > 246 )
 495           p += 1;
 496       }
 497       else
 498       {
 499         /* This is not a number, hence it's an operator.  Compute its code */
 500         /* and look for it in our current list.                            */
 501
 502         FT_UInt                  code;
 503         FT_UInt                  num_args = (FT_UInt)
 504                                               ( parser->top - parser->stack );
 505         const T2_Field_Handler*  field;
 506
 507
 508         /* first of all, a trivial check */
 509         if ( num_args < 1 )
 510           goto Stack_Underflow;
 511
 512         *parser->top = p;
 513         code = v;
 514         if ( v == 12 )
 515         {
 516           /* two byte operator */
 517           p++;
 518           code = 0x100 | p[0];
 519         }
 520         code = code | parser->object_code;
 521
 522         for ( field = t2_field_handlers; field->kind; field++ )
 523         {
 524           if ( field->code == (FT_Int)code )
 525           {
 526             /* we found our field's handler; read it */
 527             FT_Long   val;
 528             FT_Byte*  q = (FT_Byte*)parser->object + field->offset;
 529
 530
 531             switch ( field->kind )
 532             {
 533             case t2_kind_bool:
 534             case t2_kind_string:
 535             case t2_kind_num:
 536               val = t2_parse_num( parser->stack );
 537               goto Store_Number;
 538
 539             case t2_kind_fixed:
 540               val = t2_parse_fixed( parser->stack );
 541
 542             Store_Number:
 543               switch ( field->size )
 544               {
 545               case 1:
 546                 *(FT_Byte*)q = (FT_Byte)val;
 547                 break;
 548
 549               case 2:
 550                 *(FT_Short*)q = (FT_Short)val;
 551                 break;
 552
 553               case 4:
 554                 *(FT_Int32*)q = (FT_Int)val;
 555                 break;
 556
 557               default:  /* for 64-bit systems where long is 8 bytes */
 558                 *(FT_Long*)q = val;
 559               }
 560               break;
 561
 562             case t2_kind_delta:
 563               {
 564                 FT_Byte*   qcount = (FT_Byte*)parser->object +
 565                                       field->count_offset;
 566
 567                 FT_Long    val;
 568                 FT_Byte**  data = parser->stack;
 569
 570
 571                 if ( num_args > field->array_max )
 572                   num_args = field->array_max;
 573
 574                 /* store count */
 575                 *qcount = (FT_Byte)num_args;
 576
 577                 val = 0;
 578                 while ( num_args > 0 )
 579                 {
 580                   val += t2_parse_num( data++ );
 581                   switch ( field->size )
 582                   {
 583                   case 1:
 584                     *(FT_Byte*)q = (FT_Byte)val;
 585                     break;
 586
 587                   case 2:
 588                     *(FT_Short*)q = (FT_Short)val;
 589                     break;
 590
 591                   case 4:
 592                     *(FT_Int32*)q = (FT_Int)val;
 593                     break;
 594
 595                   default:  /* for 64-bit systems */
 596                     *(FT_Long*)q = val;
 597                   }
 598
 599                   q += field->size;
 600                   num_args--;
 601                 }
 602               }
 603               break;
 604
 605             default:  /* callback */
 606               error = field->reader( parser );
 607               if ( error )
 608                 goto Exit;
 609             }
 610             goto Found;
 611           }
 612         }
 613
 614         /* this is an unknown operator, or it is unsupported; */
 615         /* we will ignore it for now.                         */
 616
 617       Found:
 618         /* clear stack */
 619         parser->top = parser->stack;
 620       }
 621       p++;
 622     }
 623
 624   Exit:
 625     return error;
 626
 627   Stack_Overflow:
 628     error = T2_Err_Invalid_Argument;
 629     goto Exit;
 630
 631   Stack_Underflow:
 632     error = T2_Err_Invalid_Argument;
 633     goto Exit;
 634
 635   Syntax_Error:
 636     error = T2_Err_Invalid_Argument;
 637     goto Exit;
 638   }
 639
 640
 641 /* END */