src/third_party/freetype2/src/src/gxvalid/gxvmort.c

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  gxvmort.c                                                              */
   4 /*                                                                         */
   5 /*    TrueTypeGX/AAT mort table validation (body).                         */
   6 /*                                                                         */
   7 /*  Copyright 2005 by suzuki toshiya, Masatake YAMATO, Red Hat K.K.,       */
   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 /*                                                                         */
  20 /* gxvalid is derived from both gxlayout module and otvalid module.        */
  21 /* Development of gxlayout is supported by the Information-technology      */
  22 /* Promotion Agency(IPA), Japan.                                           */
  23 /*                                                                         */
  24 /***************************************************************************/
  25
  26
  27 #include "gxvmort.h"
  28 #include "gxvfeat.h"
  29
  30
  31   /*************************************************************************/
  32   /*                                                                       */
  33   /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
  34   /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
  35   /* messages during execution.                                            */
  36   /*                                                                       */
  37 #undef  FT_COMPONENT
  38 #define FT_COMPONENT  trace_gxvmort
  39
  40
  41   static void
  42   gxv_mort_feature_validate( GXV_mort_feature  f,
  43                              GXV_Validator     valid )
  44   {
  45     if ( f->featureType >= gxv_feat_registry_length )
  46     {
  47       GXV_TRACE(( "featureType %d is out of registered range, "
  48                   "setting %d is unchecked\n",
  49                   f->featureType, f->featureSetting ));
  50       GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA );
  51     }
  52     else if ( !gxv_feat_registry[f->featureType].existence )
  53     {
  54       GXV_TRACE(( "featureType %d is within registered area "
  55                   "but undefined, setting %d is unchecked\n",
  56                   f->featureType, f->featureSetting ));
  57       GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA );
  58     }
  59     else
  60     {
  61       FT_Byte  nSettings_max;
  62
  63
  64       /* nSettings in gxvfeat.c is halved for exclusive on/off settings */
  65       nSettings_max = gxv_feat_registry[f->featureType].nSettings;
  66       if ( gxv_feat_registry[f->featureType].exclusive )
  67         nSettings_max = (FT_Byte)( 2 * nSettings_max );
  68
  69       GXV_TRACE(( "featureType %d is registered", f->featureType ));
  70       GXV_TRACE(( "setting %d", f->featureSetting ));
  71
  72       if ( f->featureSetting > nSettings_max )
  73       {
  74         GXV_TRACE(( "out of defined range %d", nSettings_max ));
  75         GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA );
  76       }
  77       GXV_TRACE(( "\n" ));
  78     }
  79
  80     /* TODO: enableFlags must be unique value in specified chain?  */
  81   }
  82
  83
  84   /*
  85    * nFeatureFlags is typed to FT_ULong to accept that in
  86    * mort (typed FT_UShort) and morx (typed FT_ULong).
  87    */
  88   FT_LOCAL_DEF( void )
  89   gxv_mort_featurearray_validate( FT_Bytes       table,
  90                                   FT_Bytes       limit,
  91                                   FT_ULong       nFeatureFlags,
  92                                   GXV_Validator  valid )
  93   {
  94     FT_Bytes  p = table;
  95     FT_ULong  i;
  96
  97     GXV_mort_featureRec  f = GXV_MORT_FEATURE_OFF;
  98
  99
 100     GXV_NAME_ENTER( "mort feature list" );
 101     for ( i = 0; i < nFeatureFlags; i++ )
 102     {
 103       GXV_LIMIT_CHECK( 2 + 2 + 4 + 4 );
 104       f.featureType    = FT_NEXT_USHORT( p );
 105       f.featureSetting = FT_NEXT_USHORT( p );
 106       f.enableFlags    = FT_NEXT_ULONG( p );
 107       f.disableFlags   = FT_NEXT_ULONG( p );
 108
 109       gxv_mort_feature_validate( &f, valid );
 110     }
 111
 112     if ( !IS_GXV_MORT_FEATURE_OFF( f ) )
 113       FT_INVALID_DATA;
 114
 115     valid->subtable_length = p - table;
 116     GXV_EXIT;
 117   }
 118
 119
 120   FT_LOCAL_DEF( void )
 121   gxv_mort_coverage_validate( FT_UShort      coverage,
 122                               GXV_Validator  valid )
 123   {
 124     FT_UNUSED( valid );
 125
 126     if ( coverage & 0x8000U )
 127       GXV_TRACE(( " this subtable is for vertical text only\n" ));
 128     else
 129       GXV_TRACE(( " this subtable is for horizontal text only\n" ));
 130
 131     if ( coverage & 0x4000 )
 132       GXV_TRACE(( " this subtable is applied to glyph array "
 133                   "in descending order\n" ));
 134     else
 135       GXV_TRACE(( " this subtable is applied to glyph array "
 136                   "in ascending order\n" ));
 137
 138     if ( coverage & 0x2000 )
 139       GXV_TRACE(( " this subtable is forcibly applied to "
 140                   "vertical/horizontal text\n" ));
 141
 142     if ( coverage & 0x1FF8 )
 143       GXV_TRACE(( " coverage has non-zero bits in reserved area\n" ));
 144   }
 145
 146
 147   static void
 148   gxv_mort_subtables_validate( FT_Bytes       table,
 149                                FT_Bytes       limit,
 150                                FT_UShort      nSubtables,
 151                                GXV_Validator  valid )
 152   {
 153     FT_Bytes  p = table;
 154
 155     GXV_Validate_Func fmt_funcs_table[] =
 156     {
 157       gxv_mort_subtable_type0_validate, /* 0 */
 158       gxv_mort_subtable_type1_validate, /* 1 */
 159       gxv_mort_subtable_type2_validate, /* 2 */
 160       NULL,                             /* 3 */
 161       gxv_mort_subtable_type4_validate, /* 4 */
 162       gxv_mort_subtable_type5_validate, /* 5 */
 163
 164     };
 165
 166     GXV_Validate_Func  func;
 167     FT_UShort          i;
 168
 169
 170     GXV_NAME_ENTER( "subtables in a chain" );
 171
 172     for ( i = 0; i < nSubtables; i++ )
 173     {
 174       FT_UShort  length;
 175       FT_UShort  coverage;
 176 #ifdef GXV_LOAD_UNUSED_VARS
 177       FT_ULong   subFeatureFlags;
 178 #endif
 179       FT_UInt    type;
 180       FT_UInt    rest;
 181
 182
 183       GXV_LIMIT_CHECK( 2 + 2 + 4 );
 184       length          = FT_NEXT_USHORT( p );
 185       coverage        = FT_NEXT_USHORT( p );
 186 #ifdef GXV_LOAD_UNUSED_VARS
 187       subFeatureFlags = FT_NEXT_ULONG( p );
 188 #else
 189       p += 4;
 190 #endif
 191
 192       GXV_TRACE(( "validating chain subtable %d/%d (%d bytes)\n",
 193                   i + 1, nSubtables, length ));
 194       type = coverage & 0x0007;
 195       rest = length - ( 2 + 2 + 4 );
 196
 197       GXV_LIMIT_CHECK( rest );
 198       gxv_mort_coverage_validate( coverage, valid );
 199
 200       if ( type > 5 )
 201         FT_INVALID_FORMAT;
 202
 203       func = fmt_funcs_table[type];
 204       if ( func == NULL )
 205         GXV_TRACE(( "morx type %d is reserved\n", type ));
 206
 207       func( p, p + rest, valid );
 208
 209       p += rest;
 210       /* TODO: validate subFeatureFlags */
 211     }
 212
 213     valid->subtable_length = p - table;
 214
 215     GXV_EXIT;
 216   }
 217
 218
 219   static void
 220   gxv_mort_chain_validate( FT_Bytes       table,
 221                            FT_Bytes       limit,
 222                            GXV_Validator  valid )
 223   {
 224     FT_Bytes   p = table;
 225 #ifdef GXV_LOAD_UNUSED_VARS
 226     FT_ULong   defaultFlags;
 227 #endif
 228     FT_ULong   chainLength;
 229     FT_UShort  nFeatureFlags;
 230     FT_UShort  nSubtables;
 231
 232
 233     GXV_NAME_ENTER( "mort chain header" );
 234
 235     GXV_LIMIT_CHECK( 4 + 4 + 2 + 2 );
 236 #ifdef GXV_LOAD_UNUSED_VARS
 237     defaultFlags  = FT_NEXT_ULONG( p );
 238 #else
 239     p += 4;
 240 #endif
 241     chainLength   = FT_NEXT_ULONG( p );
 242     nFeatureFlags = FT_NEXT_USHORT( p );
 243     nSubtables    = FT_NEXT_USHORT( p );
 244
 245     gxv_mort_featurearray_validate( p, table + chainLength,
 246                                     nFeatureFlags, valid );
 247     p += valid->subtable_length;
 248     gxv_mort_subtables_validate( p, table + chainLength, nSubtables, valid );
 249     valid->subtable_length = chainLength;
 250
 251     /* TODO: validate defaultFlags */
 252     GXV_EXIT;
 253   }
 254
 255
 256   FT_LOCAL_DEF( void )
 257   gxv_mort_validate( FT_Bytes      table,
 258                      FT_Face       face,
 259                      FT_Validator  ftvalid )
 260   {
 261     GXV_ValidatorRec  validrec;
 262     GXV_Validator     valid = &validrec;
 263     FT_Bytes          p     = table;
 264     FT_Bytes          limit = 0;
 265     FT_ULong          version;
 266     FT_ULong          nChains;
 267     FT_ULong          i;
 268
 269
 270     valid->root = ftvalid;
 271     valid->face = face;
 272     limit       = valid->root->limit;
 273
 274     FT_TRACE3(( "validating `mort' table\n" ));
 275     GXV_INIT;
 276
 277     GXV_LIMIT_CHECK( 4 + 4 );
 278     version = FT_NEXT_ULONG( p );
 279     nChains = FT_NEXT_ULONG( p );
 280
 281     if (version != 0x00010000UL)
 282       FT_INVALID_FORMAT;
 283
 284     for ( i = 0; i < nChains; i++ )
 285     {
 286       GXV_TRACE(( "validating chain %d/%d\n", i + 1, nChains ));
 287       GXV_32BIT_ALIGNMENT_VALIDATE( p - table );
 288       gxv_mort_chain_validate( p, limit, valid );
 289       p += valid->subtable_length;
 290     }
 291
 292     FT_TRACE4(( "\n" ));
 293   }
 294
 295
 296 /* END */