src/gxvalid/gxvmort1.c

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  gxvmort1.c                                                             */
   4 /*                                                                         */
   5 /*    TrueTypeGX/AAT mort table validation                                 */
   6 /*    body for type1 (Contextual Substitution) subtable.                   */
   7 /*                                                                         */
   8 /*  Copyright 2005, 2007 by suzuki toshiya, Masatake YAMATO, Red Hat K.K., */
   9 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
  10 /*                                                                         */
  11 /*  This file is part of the FreeType project, and may only be used,       */
  12 /*  modified, and distributed under the terms of the FreeType project      */
  13 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
  14 /*  this file you indicate that you have read the license and              */
  15 /*  understand and accept it fully.                                        */
  16 /*                                                                         */
  17 /***************************************************************************/
  18
  19 /***************************************************************************/
  20 /*                                                                         */
  21 /* gxvalid is derived from both gxlayout module and otvalid module.        */
  22 /* Development of gxlayout is supported by the Information-technology      */
  23 /* Promotion Agency(IPA), Japan.                                           */
  24 /*                                                                         */
  25 /***************************************************************************/
  26
  27
  28 #include "gxvmort.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   typedef struct  GXV_mort_subtable_type1_StateOptRec_
  42   {
  43     FT_UShort  substitutionTable;
  44     FT_UShort  substitutionTable_length;
  45
  46   }  GXV_mort_subtable_type1_StateOptRec,
  47     *GXV_mort_subtable_type1_StateOptRecData;
  48
  49 #define GXV_MORT_SUBTABLE_TYPE1_HEADER_SIZE \
  50           ( GXV_STATETABLE_HEADER_SIZE + 2 )
  51
  52
  53   static void
  54   gxv_mort_subtable_type1_substitutionTable_load( FT_Bytes       table,
  55                                                   FT_Bytes       limit,
  56                                                   GXV_Validator  valid )
  57   {
  58     FT_Bytes  p = table;
  59
  60     GXV_mort_subtable_type1_StateOptRecData  optdata =
  61       (GXV_mort_subtable_type1_StateOptRecData)valid->statetable.optdata;
  62
  63
  64     GXV_LIMIT_CHECK( 2 );
  65     optdata->substitutionTable = FT_NEXT_USHORT( p );
  66   }
  67
  68
  69   static void
  70   gxv_mort_subtable_type1_subtable_setup( FT_UShort      table_size,
  71                                           FT_UShort      classTable,
  72                                           FT_UShort      stateArray,
  73                                           FT_UShort      entryTable,
  74                                           FT_UShort*     classTable_length_p,
  75                                           FT_UShort*     stateArray_length_p,
  76                                           FT_UShort*     entryTable_length_p,
  77                                           GXV_Validator  valid )
  78   {
  79     FT_UShort  o[4];
  80     FT_UShort  *l[4];
  81     FT_UShort  buff[5];
  82
  83     GXV_mort_subtable_type1_StateOptRecData  optdata =
  84       (GXV_mort_subtable_type1_StateOptRecData)valid->statetable.optdata;
  85
  86
  87     o[0] = classTable;
  88     o[1] = stateArray;
  89     o[2] = entryTable;
  90     o[3] = optdata->substitutionTable;
  91     l[0] = classTable_length_p;
  92     l[1] = stateArray_length_p;
  93     l[2] = entryTable_length_p;
  94     l[3] = &( optdata->substitutionTable_length );
  95
  96     gxv_set_length_by_ushort_offset( o, l, buff, 4, table_size, valid );
  97   }
  98
  99
 100   static void
 101   gxv_mort_subtable_type1_offset_to_subst_validate(
 102     FT_Short          wordOffset,
 103     const FT_String*  tag,
 104     FT_Byte           state,
 105     GXV_Validator     valid )
 106   {
 107     FT_UShort  substTable;
 108     FT_UShort  substTable_limit;
 109
 110     FT_UNUSED( tag );
 111     FT_UNUSED( state );
 112
 113
 114     substTable =
 115       ((GXV_mort_subtable_type1_StateOptRec *)
 116        (valid->statetable.optdata))->substitutionTable;
 117     substTable_limit =
 118       (FT_UShort)( substTable +
 119                    ((GXV_mort_subtable_type1_StateOptRec *)
 120                     (valid->statetable.optdata))->substitutionTable_length );
 121
 122     valid->min_gid = (FT_UShort)( ( substTable       - wordOffset * 2 ) / 2 );
 123     valid->max_gid = (FT_UShort)( ( substTable_limit - wordOffset * 2 ) / 2 );
 124     valid->max_gid = (FT_UShort)( FT_MAX( valid->max_gid,
 125                                           valid->face->num_glyphs ) );
 126
 127     /* XXX: check range? */
 128
 129     /* TODO: min_gid & max_gid comparison with ClassTable contents */
 130   }
 131
 132
 133   static void
 134   gxv_mort_subtable_type1_entry_validate(
 135     FT_Byte                         state,
 136     FT_UShort                       flags,
 137     GXV_StateTable_GlyphOffsetCPtr  glyphOffset_p,
 138     FT_Bytes                        table,
 139     FT_Bytes                        limit,
 140     GXV_Validator                   valid )
 141   {
 142 #ifdef GXV_LOAD_UNUSED_VARS
 143     FT_UShort  setMark;
 144     FT_UShort  dontAdvance;
 145 #endif
 146     FT_UShort  reserved;
 147     FT_Short   markOffset;
 148     FT_Short   currentOffset;
 149
 150     FT_UNUSED( table );
 151     FT_UNUSED( limit );
 152
 153
 154 #ifdef GXV_LOAD_UNUSED_VARS
 155     setMark       = (FT_UShort)(   flags >> 15            );
 156     dontAdvance   = (FT_UShort)( ( flags >> 14 ) & 1      );
 157 #endif
 158     reserved      = (FT_Short)(    flags         & 0x3FFF );
 159
 160     markOffset    = (FT_Short)( glyphOffset_p->ul >> 16 );
 161     currentOffset = (FT_Short)( glyphOffset_p->ul       );
 162
 163     if ( 0 < reserved )
 164     {
 165       GXV_TRACE(( " non-zero bits found in reserved range\n" ));
 166       GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA );
 167     }
 168
 169     gxv_mort_subtable_type1_offset_to_subst_validate( markOffset,
 170                                                       "markOffset",
 171                                                       state,
 172                                                       valid );
 173
 174     gxv_mort_subtable_type1_offset_to_subst_validate( currentOffset,
 175                                                       "currentOffset",
 176                                                       state,
 177                                                       valid );
 178   }
 179
 180
 181   static void
 182   gxv_mort_subtable_type1_substTable_validate( FT_Bytes       table,
 183                                                FT_Bytes       limit,
 184                                                GXV_Validator  valid )
 185   {
 186     FT_Bytes   p = table;
 187     FT_UShort  num_gids = (FT_UShort)(
 188                  ((GXV_mort_subtable_type1_StateOptRec *)
 189                   (valid->statetable.optdata))->substitutionTable_length / 2 );
 190     FT_UShort  i;
 191
 192
 193     GXV_NAME_ENTER( "validating contents of substitutionTable" );
 194     for ( i = 0; i < num_gids ; i ++ )
 195     {
 196       FT_UShort  dst_gid;
 197
 198
 199       GXV_LIMIT_CHECK( 2 );
 200       dst_gid = FT_NEXT_USHORT( p );
 201
 202       if ( dst_gid >= 0xFFFFU )
 203         continue;
 204
 205       if ( dst_gid < valid->min_gid || valid->max_gid < dst_gid )
 206       {
 207         GXV_TRACE(( "substTable include a strange gid[%d]=%d >"
 208                     " out of define range (%d..%d)\n",
 209                     i, dst_gid, valid->min_gid, valid->max_gid ));
 210         GXV_SET_ERR_IF_PARANOID( FT_INVALID_GLYPH_ID );
 211       }
 212     }
 213
 214     GXV_EXIT;
 215   }
 216
 217
 218   /*
 219    * subtable for Contextual glyph substitution is a modified StateTable.
 220    * In addition to classTable, stateArray, and entryTable, the field
 221    * `substitutionTable' is added.
 222    */
 223   FT_LOCAL_DEF( void )
 224   gxv_mort_subtable_type1_validate( FT_Bytes       table,
 225                                     FT_Bytes       limit,
 226                                     GXV_Validator  valid )
 227   {
 228     FT_Bytes  p = table;
 229
 230     GXV_mort_subtable_type1_StateOptRec  st_rec;
 231
 232
 233     GXV_NAME_ENTER( "mort chain subtable type1 (Contextual Glyph Subst)" );
 234
 235     GXV_LIMIT_CHECK( GXV_MORT_SUBTABLE_TYPE1_HEADER_SIZE );
 236
 237     valid->statetable.optdata =
 238       &st_rec;
 239     valid->statetable.optdata_load_func =
 240       gxv_mort_subtable_type1_substitutionTable_load;
 241     valid->statetable.subtable_setup_func =
 242       gxv_mort_subtable_type1_subtable_setup;
 243     valid->statetable.entry_glyphoffset_fmt =
 244       GXV_GLYPHOFFSET_ULONG;
 245     valid->statetable.entry_validate_func =
 246
 247       gxv_mort_subtable_type1_entry_validate;
 248     gxv_StateTable_validate( p, limit, valid );
 249
 250     gxv_mort_subtable_type1_substTable_validate(
 251       table + st_rec.substitutionTable,
 252       table + st_rec.substitutionTable + st_rec.substitutionTable_length,
 253       valid );
 254
 255     GXV_EXIT;
 256   }
 257
 258
 259 /* END */