extension/SDL2_ttf-2.0.14/external/freetype-2.4.12/src/truetype/ttpload.c

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  ttpload.c                                                              */
   4 /*                                                                         */
   5 /*    TrueType-specific tables loader (body).                              */
   6 /*                                                                         */
   7 /*  Copyright 1996-2002, 2004-2013 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 #include <ft2build.h>
  20 #include FT_INTERNAL_DEBUG_H
  21 #include FT_INTERNAL_OBJECTS_H
  22 #include FT_INTERNAL_STREAM_H
  23 #include FT_TRUETYPE_TAGS_H
  24
  25 #include "ttpload.h"
  26
  27 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
  28 #include "ttgxvar.h"
  29 #endif
  30
  31 #include "tterrors.h"
  32
  33
  34   /*************************************************************************/
  35   /*                                                                       */
  36   /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
  37   /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
  38   /* messages during execution.                                            */
  39   /*                                                                       */
  40 #undef  FT_COMPONENT
  41 #define FT_COMPONENT  trace_ttpload
  42
  43
  44   /*************************************************************************/
  45   /*                                                                       */
  46   /* <Function>                                                            */
  47   /*    tt_face_load_loca                                                  */
  48   /*                                                                       */
  49   /* <Description>                                                         */
  50   /*    Load the locations table.                                          */
  51   /*                                                                       */
  52   /* <InOut>                                                               */
  53   /*    face   :: A handle to the target face object.                      */
  54   /*                                                                       */
  55   /* <Input>                                                               */
  56   /*    stream :: The input stream.                                        */
  57   /*                                                                       */
  58   /* <Return>                                                              */
  59   /*    FreeType error code.  0 means success.                             */
  60   /*                                                                       */
  61   FT_LOCAL_DEF( FT_Error )
  62   tt_face_load_loca( TT_Face    face,
  63                      FT_Stream  stream )
  64   {
  65     FT_Error  error;
  66     FT_ULong  table_len;
  67     FT_Int    shift;
  68
  69
  70     /* we need the size of the `glyf' table for malformed `loca' tables */
  71     error = face->goto_table( face, TTAG_glyf, stream, &face->glyf_len );
  72
  73     /* it is possible that a font doesn't have a glyf table at all */
  74     /* or its size is zero                                         */
  75     if ( FT_ERR_EQ( error, Table_Missing ) )
  76       face->glyf_len = 0;
  77     else if ( error )
  78       goto Exit;
  79
  80     FT_TRACE2(( "Locations " ));
  81     error = face->goto_table( face, TTAG_loca, stream, &table_len );
  82     if ( error )
  83     {
  84       error = FT_THROW( Locations_Missing );
  85       goto Exit;
  86     }
  87
  88     if ( face->header.Index_To_Loc_Format != 0 )
  89     {
  90       shift = 2;
  91
  92       if ( table_len >= 0x40000L )
  93       {
  94         FT_TRACE2(( "table too large\n" ));
  95         error = FT_THROW( Invalid_Table );
  96         goto Exit;
  97       }
  98       face->num_locations = table_len >> shift;
  99     }
 100     else
 101     {
 102       shift = 1;
 103
 104       if ( table_len >= 0x20000L )
 105       {
 106         FT_TRACE2(( "table too large\n" ));
 107         error = FT_THROW( Invalid_Table );
 108         goto Exit;
 109       }
 110       face->num_locations = table_len >> shift;
 111     }
 112
 113     if ( face->num_locations != (FT_ULong)face->root.num_glyphs + 1 )
 114     {
 115       FT_TRACE2(( "glyph count mismatch!  loca: %d, maxp: %d\n",
 116                   face->num_locations - 1, face->root.num_glyphs ));
 117
 118       /* we only handle the case where `maxp' gives a larger value */
 119       if ( face->num_locations <= (FT_ULong)face->root.num_glyphs )
 120       {
 121         FT_Long   new_loca_len =
 122                     ( (FT_Long)( face->root.num_glyphs ) + 1 ) << shift;
 123
 124         TT_Table  entry = face->dir_tables;
 125         TT_Table  limit = entry + face->num_tables;
 126
 127         FT_Long   pos  = FT_Stream_Pos( stream );
 128         FT_Long   dist = 0x7FFFFFFFL;
 129
 130
 131         /* compute the distance to next table in font file */
 132         for ( ; entry < limit; entry++ )
 133         {
 134           FT_Long  diff = entry->Offset - pos;
 135
 136
 137           if ( diff > 0 && diff < dist )
 138             dist = diff;
 139         }
 140
 141         if ( entry == limit )
 142         {
 143           /* `loca' is the last table */
 144           dist = stream->size - pos;
 145         }
 146
 147         if ( new_loca_len <= dist )
 148         {
 149           face->num_locations = face->root.num_glyphs + 1;
 150           table_len           = new_loca_len;
 151
 152           FT_TRACE2(( "adjusting num_locations to %d\n",
 153                       face->num_locations ));
 154         }
 155       }
 156     }
 157
 158     /*
 159      * Extract the frame.  We don't need to decompress it since
 160      * we are able to parse it directly.
 161      */
 162     if ( FT_FRAME_EXTRACT( table_len, face->glyph_locations ) )
 163       goto Exit;
 164
 165     FT_TRACE2(( "loaded\n" ));
 166
 167   Exit:
 168     return error;
 169   }
 170
 171
 172   FT_LOCAL_DEF( FT_ULong )
 173   tt_face_get_location( TT_Face   face,
 174                         FT_UInt   gindex,
 175                         FT_UInt  *asize )
 176   {
 177     FT_ULong  pos1, pos2;
 178     FT_Byte*  p;
 179     FT_Byte*  p_limit;
 180
 181
 182     pos1 = pos2 = 0;
 183
 184     if ( gindex < face->num_locations )
 185     {
 186       if ( face->header.Index_To_Loc_Format != 0 )
 187       {
 188         p       = face->glyph_locations + gindex * 4;
 189         p_limit = face->glyph_locations + face->num_locations * 4;
 190
 191         pos1 = FT_NEXT_ULONG( p );
 192         pos2 = pos1;
 193
 194         if ( p + 4 <= p_limit )
 195           pos2 = FT_NEXT_ULONG( p );
 196       }
 197       else
 198       {
 199         p       = face->glyph_locations + gindex * 2;
 200         p_limit = face->glyph_locations + face->num_locations * 2;
 201
 202         pos1 = FT_NEXT_USHORT( p );
 203         pos2 = pos1;
 204
 205         if ( p + 2 <= p_limit )
 206           pos2 = FT_NEXT_USHORT( p );
 207
 208         pos1 <<= 1;
 209         pos2 <<= 1;
 210       }
 211     }
 212
 213     /* Check broken location data */
 214     if ( pos1 > face->glyf_len )
 215     {
 216       FT_TRACE1(( "tt_face_get_location:"
 217                   " too large offset=0x%08lx found for gid=0x%04lx,"
 218                   " exceeding the end of glyf table (0x%08lx)\n",
 219                   pos1, gindex, face->glyf_len ));
 220       *asize = 0;
 221       return 0;
 222     }
 223
 224     if ( pos2 > face->glyf_len )
 225     {
 226       FT_TRACE1(( "tt_face_get_location:"
 227                   " too large offset=0x%08lx found for gid=0x%04lx,"
 228                   " truncate at the end of glyf table (0x%08lx)\n",
 229                   pos2, gindex + 1, face->glyf_len ));
 230       pos2 = face->glyf_len;
 231     }
 232
 233     /* The `loca' table must be ordered; it refers to the length of */
 234     /* an entry as the difference between the current and the next  */
 235     /* position.  However, there do exist (malformed) fonts which   */
 236     /* don't obey this rule, so we are only able to provide an      */
 237     /* upper bound for the size.                                    */
 238     /*                                                              */
 239     /* We get (intentionally) a wrong, non-zero result in case the  */
 240     /* `glyf' table is missing.                                     */
 241     if ( pos2 >= pos1 )
 242       *asize = (FT_UInt)( pos2 - pos1 );
 243     else
 244       *asize = (FT_UInt)( face->glyf_len - pos1 );
 245
 246     return pos1;
 247   }
 248
 249
 250   FT_LOCAL_DEF( void )
 251   tt_face_done_loca( TT_Face  face )
 252   {
 253     FT_Stream  stream = face->root.stream;
 254
 255
 256     FT_FRAME_RELEASE( face->glyph_locations );
 257     face->num_locations = 0;
 258   }
 259
 260
 261
 262   /*************************************************************************/
 263   /*                                                                       */
 264   /* <Function>                                                            */
 265   /*    tt_face_load_cvt                                                   */
 266   /*                                                                       */
 267   /* <Description>                                                         */
 268   /*    Load the control value table into a face object.                   */
 269   /*                                                                       */
 270   /* <InOut>                                                               */
 271   /*    face   :: A handle to the target face object.                      */
 272   /*                                                                       */
 273   /* <Input>                                                               */
 274   /*    stream :: A handle to the input stream.                            */
 275   /*                                                                       */
 276   /* <Return>                                                              */
 277   /*    FreeType error code.  0 means success.                             */
 278   /*                                                                       */
 279   FT_LOCAL_DEF( FT_Error )
 280   tt_face_load_cvt( TT_Face    face,
 281                     FT_Stream  stream )
 282   {
 283 #ifdef TT_USE_BYTECODE_INTERPRETER
 284
 285     FT_Error   error;
 286     FT_Memory  memory = stream->memory;
 287     FT_ULong   table_len;
 288
 289
 290     FT_TRACE2(( "CVT " ));
 291
 292     error = face->goto_table( face, TTAG_cvt, stream, &table_len );
 293     if ( error )
 294     {
 295       FT_TRACE2(( "is missing\n" ));
 296
 297       face->cvt_size = 0;
 298       face->cvt      = NULL;
 299       error          = FT_Err_Ok;
 300
 301       goto Exit;
 302     }
 303
 304     face->cvt_size = table_len / 2;
 305
 306     if ( FT_NEW_ARRAY( face->cvt, face->cvt_size ) )
 307       goto Exit;
 308
 309     if ( FT_FRAME_ENTER( face->cvt_size * 2L ) )
 310       goto Exit;
 311
 312     {
 313       FT_Short*  cur   = face->cvt;
 314       FT_Short*  limit = cur + face->cvt_size;
 315
 316
 317       for ( ; cur < limit; cur++ )
 318         *cur = FT_GET_SHORT();
 319     }
 320
 321     FT_FRAME_EXIT();
 322     FT_TRACE2(( "loaded\n" ));
 323
 324 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
 325     if ( face->doblend )
 326       error = tt_face_vary_cvt( face, stream );
 327 #endif
 328
 329   Exit:
 330     return error;
 331
 332 #else /* !TT_USE_BYTECODE_INTERPRETER */
 333
 334     FT_UNUSED( face   );
 335     FT_UNUSED( stream );
 336
 337     return FT_Err_Ok;
 338
 339 #endif
 340   }
 341
 342
 343   /*************************************************************************/
 344   /*                                                                       */
 345   /* <Function>                                                            */
 346   /*    tt_face_load_fpgm                                                  */
 347   /*                                                                       */
 348   /* <Description>                                                         */
 349   /*    Load the font program.                                             */
 350   /*                                                                       */
 351   /* <InOut>                                                               */
 352   /*    face   :: A handle to the target face object.                      */
 353   /*                                                                       */
 354   /* <Input>                                                               */
 355   /*    stream :: A handle to the input stream.                            */
 356   /*                                                                       */
 357   /* <Return>                                                              */
 358   /*    FreeType error code.  0 means success.                             */
 359   /*                                                                       */
 360   FT_LOCAL_DEF( FT_Error )
 361   tt_face_load_fpgm( TT_Face    face,
 362                      FT_Stream  stream )
 363   {
 364 #ifdef TT_USE_BYTECODE_INTERPRETER
 365
 366     FT_Error  error;
 367     FT_ULong  table_len;
 368
 369
 370     FT_TRACE2(( "Font program " ));
 371
 372     /* The font program is optional */
 373     error = face->goto_table( face, TTAG_fpgm, stream, &table_len );
 374     if ( error )
 375     {
 376       face->font_program      = NULL;
 377       face->font_program_size = 0;
 378       error                   = FT_Err_Ok;
 379
 380       FT_TRACE2(( "is missing\n" ));
 381     }
 382     else
 383     {
 384       face->font_program_size = table_len;
 385       if ( FT_FRAME_EXTRACT( table_len, face->font_program ) )
 386         goto Exit;
 387
 388       FT_TRACE2(( "loaded, %12d bytes\n", face->font_program_size ));
 389     }
 390
 391   Exit:
 392     return error;
 393
 394 #else /* !TT_USE_BYTECODE_INTERPRETER */
 395
 396     FT_UNUSED( face   );
 397     FT_UNUSED( stream );
 398
 399     return FT_Err_Ok;
 400
 401 #endif
 402   }
 403
 404
 405   /*************************************************************************/
 406   /*                                                                       */
 407   /* <Function>                                                            */
 408   /*    tt_face_load_prep                                                  */
 409   /*                                                                       */
 410   /* <Description>                                                         */
 411   /*    Load the cvt program.                                              */
 412   /*                                                                       */
 413   /* <InOut>                                                               */
 414   /*    face   :: A handle to the target face object.                      */
 415   /*                                                                       */
 416   /* <Input>                                                               */
 417   /*    stream :: A handle to the input stream.                            */
 418   /*                                                                       */
 419   /* <Return>                                                              */
 420   /*    FreeType error code.  0 means success.                             */
 421   /*                                                                       */
 422   FT_LOCAL_DEF( FT_Error )
 423   tt_face_load_prep( TT_Face    face,
 424                      FT_Stream  stream )
 425   {
 426 #ifdef TT_USE_BYTECODE_INTERPRETER
 427
 428     FT_Error  error;
 429     FT_ULong  table_len;
 430
 431
 432     FT_TRACE2(( "Prep program " ));
 433
 434     error = face->goto_table( face, TTAG_prep, stream, &table_len );
 435     if ( error )
 436     {
 437       face->cvt_program      = NULL;
 438       face->cvt_program_size = 0;
 439       error                  = FT_Err_Ok;
 440
 441       FT_TRACE2(( "is missing\n" ));
 442     }
 443     else
 444     {
 445       face->cvt_program_size = table_len;
 446       if ( FT_FRAME_EXTRACT( table_len, face->cvt_program ) )
 447         goto Exit;
 448
 449       FT_TRACE2(( "loaded, %12d bytes\n", face->cvt_program_size ));
 450     }
 451
 452   Exit:
 453     return error;
 454
 455 #else /* !TT_USE_BYTECODE_INTERPRETER */
 456
 457     FT_UNUSED( face   );
 458     FT_UNUSED( stream );
 459
 460     return FT_Err_Ok;
 461
 462 #endif
 463   }
 464
 465
 466   /*************************************************************************/
 467   /*                                                                       */
 468   /* <Function>                                                            */
 469   /*    tt_face_load_hdmx                                                  */
 470   /*                                                                       */
 471   /* <Description>                                                         */
 472   /*    Load the `hdmx' table into the face object.                        */
 473   /*                                                                       */
 474   /* <Input>                                                               */
 475   /*    face   :: A handle to the target face object.                      */
 476   /*                                                                       */
 477   /*    stream :: A handle to the input stream.                            */
 478   /*                                                                       */
 479   /* <Return>                                                              */
 480   /*    FreeType error code.  0 means success.                             */
 481   /*                                                                       */
 482
 483   FT_LOCAL_DEF( FT_Error )
 484   tt_face_load_hdmx( TT_Face    face,
 485                      FT_Stream  stream )
 486   {
 487     FT_Error   error;
 488     FT_Memory  memory = stream->memory;
 489     FT_UInt    version, nn, num_records;
 490     FT_ULong   table_size, record_size;
 491     FT_Byte*   p;
 492     FT_Byte*   limit;
 493
 494
 495     /* this table is optional */
 496     error = face->goto_table( face, TTAG_hdmx, stream, &table_size );
 497     if ( error || table_size < 8 )
 498       return FT_Err_Ok;
 499
 500     if ( FT_FRAME_EXTRACT( table_size, face->hdmx_table ) )
 501       goto Exit;
 502
 503     p     = face->hdmx_table;
 504     limit = p + table_size;
 505
 506     version     = FT_NEXT_USHORT( p );
 507     num_records = FT_NEXT_USHORT( p );
 508     record_size = FT_NEXT_ULONG( p );
 509
 510     /* The maximum number of bytes in an hdmx device record is the */
 511     /* maximum number of glyphs + 2; this is 0xFFFF + 2; this is   */
 512     /* the reason why `record_size' is a long (which we read as    */
 513     /* unsigned long for convenience).  In practice, two bytes     */
 514     /* sufficient to hold the size value.                          */
 515     /*                                                             */
 516     /* There are at least two fonts, HANNOM-A and HANNOM-B version */
 517     /* 2.0 (2005), which get this wrong: The upper two bytes of    */
 518     /* the size value are set to 0xFF instead of 0x00.  We catch   */
 519     /* and fix this.                                               */
 520
 521     if ( record_size >= 0xFFFF0000UL )
 522       record_size &= 0xFFFFU;
 523
 524     /* The limit for `num_records' is a heuristic value. */
 525
 526     if ( version != 0 || num_records > 255 || record_size > 0x10001L )
 527     {
 528       error = FT_THROW( Invalid_File_Format );
 529       goto Fail;
 530     }
 531
 532     if ( FT_NEW_ARRAY( face->hdmx_record_sizes, num_records ) )
 533       goto Fail;
 534
 535     for ( nn = 0; nn < num_records; nn++ )
 536     {
 537       if ( p + record_size > limit )
 538         break;
 539
 540       face->hdmx_record_sizes[nn] = p[0];
 541       p                          += record_size;
 542     }
 543
 544     face->hdmx_record_count = nn;
 545     face->hdmx_table_size   = table_size;
 546     face->hdmx_record_size  = record_size;
 547
 548   Exit:
 549     return error;
 550
 551   Fail:
 552     FT_FRAME_RELEASE( face->hdmx_table );
 553     face->hdmx_table_size = 0;
 554     goto Exit;
 555   }
 556
 557
 558   FT_LOCAL_DEF( void )
 559   tt_face_free_hdmx( TT_Face  face )
 560   {
 561     FT_Stream  stream = face->root.stream;
 562     FT_Memory  memory = stream->memory;
 563
 564
 565     FT_FREE( face->hdmx_record_sizes );
 566     FT_FRAME_RELEASE( face->hdmx_table );
 567   }
 568
 569
 570   /*************************************************************************/
 571   /*                                                                       */
 572   /* Return the advance width table for a given pixel size if it is found  */
 573   /* in the font's `hdmx' table (if any).                                  */
 574   /*                                                                       */
 575   FT_LOCAL_DEF( FT_Byte* )
 576   tt_face_get_device_metrics( TT_Face  face,
 577                               FT_UInt  ppem,
 578                               FT_UInt  gindex )
 579   {
 580     FT_UInt   nn;
 581     FT_Byte*  result      = NULL;
 582     FT_ULong  record_size = face->hdmx_record_size;
 583     FT_Byte*  record      = face->hdmx_table + 8;
 584
 585
 586     for ( nn = 0; nn < face->hdmx_record_count; nn++ )
 587       if ( face->hdmx_record_sizes[nn] == ppem )
 588       {
 589         gindex += 2;
 590         if ( gindex < record_size )
 591           result = record + nn * record_size + gindex;
 592         break;
 593       }
 594
 595     return result;
 596   }
 597
 598
 599 /* END */