lib/3rdparty/freetype/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       if ( valid->root->level >= FT_VALIDATE_PARANOID )
  51         FT_INVALID_DATA;
  52     }
  53     else if ( !gxv_feat_registry[f->featureType].existence )
  54     {
  55       GXV_TRACE(( "featureType %d is within registered area "
  56                   "but undefined, setting %d is unchecked\n",
  57                   f->featureType, f->featureSetting ));
  58       if ( valid->root->level >= FT_VALIDATE_PARANOID )
  59         FT_INVALID_DATA;
  60     }
  61     else
  62     {
  63       FT_Byte  nSettings_max;
  64
  65
  66       /* nSettings in gxvfeat.c is halved for exclusive on/off settings */
  67       nSettings_max = gxv_feat_registry[f->featureType].nSettings;
  68       if ( gxv_feat_registry[f->featureType].exclusive )
  69         nSettings_max = (FT_Byte)( 2 * nSettings_max );
  70
  71       GXV_TRACE(( "featureType %d is registered", f->featureType ));
  72       GXV_TRACE(( "setting %d", f->featureSetting ));
  73
  74       if ( f->featureSetting > nSettings_max )
  75       {
  76         GXV_TRACE(( "out of defined range %d", nSettings_max ));
  77         if ( valid->root->level >= FT_VALIDATE_PARANOID )
  78           FT_INVALID_DATA;
  79       }
  80       GXV_TRACE(( "\n" ));
  81     }
  82
  83     /* TODO: enableFlags must be unique value in specified chain?  */
  84   }
  85
  86
  87   /*
  88    * nFeatureFlags is typed to FT_UInt to accept that in
  89    * mort (typed FT_UShort) and morx (typed FT_ULong).
  90    */
  91   FT_LOCAL_DEF( void )
  92   gxv_mort_featurearray_validate( FT_Bytes       table,
  93                                   FT_Bytes       limit,
  94                                   FT_UInt        nFeatureFlags,
  95                                   GXV_Validator  valid )
  96   {
  97     FT_Bytes  p = table;
  98     FT_UInt   i;
  99
 100     GXV_mort_featureRec  f = GXV_MORT_FEATURE_OFF;
 101
 102
 103     GXV_NAME_ENTER( "mort feature list" );
 104     for ( i = 0; i < nFeatureFlags; i++ )
 105     {
 106       GXV_LIMIT_CHECK( 2 + 2 + 4 + 4 );
 107       f.featureType    = FT_NEXT_USHORT( p );
 108       f.featureSetting = FT_NEXT_USHORT( p );
 109       f.enableFlags    = FT_NEXT_ULONG( p );
 110       f.disableFlags   = FT_NEXT_ULONG( p );
 111
 112       gxv_mort_feature_validate( &f, valid );
 113     }
 114
 115     if ( !IS_GXV_MORT_FEATURE_OFF( f ) )
 116       FT_INVALID_DATA;
 117
 118     valid->subtable_length = p - table;
 119     GXV_EXIT;
 120   }
 121
 122
 123   FT_LOCAL_DEF( void )
 124   gxv_mort_coverage_validate( FT_UShort      coverage,
 125                               GXV_Validator  valid )
 126   {
 127     FT_UNUSED( valid );
 128
 129     if ( coverage & 0x8000U )
 130       GXV_TRACE(( " this subtable is for vertical text only\n" ));
 131     else
 132       GXV_TRACE(( " this subtable is for horizontal text only\n" ));
 133
 134     if ( coverage & 0x4000 )
 135       GXV_TRACE(( " this subtable is applied to glyph array "
 136                   "in descending order\n" ));
 137     else
 138       GXV_TRACE(( " this subtable is applied to glyph array "
 139                   "in ascending order\n" ));
 140
 141     if ( coverage & 0x2000 )
 142       GXV_TRACE(( " this subtable is forcibly applied to "
 143                   "vertical/horizontal text\n" ));
 144
 145     if ( coverage & 0x1FF8 )
 146       GXV_TRACE(( " coverage has non-zero bits in reserved area\n" ));
 147   }
 148
 149
 150   static void
 151   gxv_mort_subtables_validate( FT_Bytes       table,
 152                                FT_Bytes       limit,
 153                                FT_UShort      nSubtables,
 154                                GXV_Validator  valid )
 155   {
 156     FT_Bytes  p = table;
 157
 158     GXV_Validate_Func fmt_funcs_table[] =
 159     {
 160       gxv_mort_subtable_type0_validate, /* 0 */
 161       gxv_mort_subtable_type1_validate, /* 1 */
 162       gxv_mort_subtable_type2_validate, /* 2 */
 163       NULL,                             /* 3 */
 164       gxv_mort_subtable_type4_validate, /* 4 */
 165       gxv_mort_subtable_type5_validate, /* 5 */
 166
 167     };
 168
 169     GXV_Validate_Func  func;
 170     FT_UShort          i;
 171
 172
 173     GXV_NAME_ENTER( "subtables in a chain" );
 174
 175     for ( i = 0; i < nSubtables; i++ )
 176     {
 177       FT_UShort  length;
 178       FT_UShort  coverage;
 179       FT_ULong   subFeatureFlags;
 180       FT_UInt    type;
 181       FT_UInt    rest;
 182
 183
 184       GXV_LIMIT_CHECK( 2 + 2 + 4 );
 185       length          = FT_NEXT_USHORT( p );
 186       coverage        = FT_NEXT_USHORT( p );
 187       subFeatureFlags = FT_NEXT_ULONG( p );
 188
 189       GXV_TRACE(( "validating chain subtable %d/%d (%d bytes)\n",
 190                   i + 1, nSubtables, length ));
 191       type = coverage & 0x0007;
 192       rest = length - ( 2 + 2 + 4 );
 193
 194       GXV_LIMIT_CHECK( rest );
 195       gxv_mort_coverage_validate( coverage, valid );
 196
 197       if ( type > 5 )
 198         FT_INVALID_FORMAT;
 199
 200       func = fmt_funcs_table[type];
 201       if ( func == NULL )
 202         GXV_TRACE(( "morx type %d is reserved\n", type ));
 203
 204       func( p, p + rest, valid );
 205
 206       p += rest;
 207     }
 208
 209     valid->subtable_length = p - table;
 210
 211     GXV_EXIT;
 212   }
 213
 214
 215   static void
 216   gxv_mort_chain_validate( FT_Bytes       table,
 217                            FT_Bytes       limit,
 218                            GXV_Validator  valid )
 219   {
 220     FT_Bytes   p = table;
 221     FT_ULong   defaultFlags;
 222     FT_ULong   chainLength;
 223     FT_UShort  nFeatureFlags;
 224     FT_UShort  nSubtables;
 225
 226
 227     GXV_NAME_ENTER( "mort chain header" );
 228
 229     GXV_LIMIT_CHECK( 4 + 4 + 2 + 2 );
 230     defaultFlags  = FT_NEXT_ULONG( p );
 231     chainLength   = FT_NEXT_ULONG( p );
 232     nFeatureFlags = FT_NEXT_USHORT( p );
 233     nSubtables    = FT_NEXT_USHORT( p );
 234
 235     gxv_mort_featurearray_validate( p, table + chainLength,
 236                                     nFeatureFlags, valid );
 237     p += valid->subtable_length;
 238     gxv_mort_subtables_validate( p, table + chainLength, nSubtables, valid );
 239     valid->subtable_length = chainLength;
 240
 241     GXV_EXIT;
 242   }
 243
 244
 245   FT_LOCAL_DEF( void )
 246   gxv_mort_validate( FT_Bytes      table,
 247                      FT_Face       face,
 248                      FT_Validator  ftvalid )
 249   {
 250     GXV_ValidatorRec  validrec;
 251     GXV_Validator     valid = &validrec;
 252     FT_Bytes          p     = table;
 253     FT_Bytes          limit = 0;
 254     FT_ULong          version;
 255     FT_ULong          nChains;
 256     FT_ULong          i;
 257
 258
 259     valid->root = ftvalid;
 260     valid->face = face;
 261     limit       = valid->root->limit;
 262
 263     FT_TRACE3(( "validating `mort' table\n" ));
 264     GXV_INIT;
 265
 266     GXV_LIMIT_CHECK( 4 + 4 );
 267     version = FT_NEXT_ULONG( p );
 268     nChains = FT_NEXT_ULONG( p );
 269
 270     if (version != 0x00010000UL)
 271       FT_INVALID_FORMAT;
 272
 273     for ( i = 0; i < nChains; i++ )
 274     {
 275       GXV_TRACE(( "validating chain %d/%d\n", i + 1, nChains ));
 276       GXV_32BIT_ALIGNMENT_VALIDATE( p - table );
 277       gxv_mort_chain_validate( p, limit, valid );
 278       p += valid->subtable_length;
 279     }
 280
 281     FT_TRACE4(( "\n" ));
 282   }
 283
 284
 285 /* END */