src/gxvalid/gxvmorx1.c

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  gxvmorx1.c                                                             */
   4 /*                                                                         */
   5 /*    TrueTypeGX/AAT morx 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 "gxvmorx.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_gxvmorx
  39
  40
  41   typedef struct  GXV_morx_subtable_type1_StateOptRec_
  42   {
  43     FT_ULong   substitutionTable;
  44     FT_ULong   substitutionTable_length;
  45     FT_UShort  substitutionTable_num_lookupTables;
  46
  47   }  GXV_morx_subtable_type1_StateOptRec,
  48     *GXV_morx_subtable_type1_StateOptRecData;
  49
  50
  51 #define GXV_MORX_SUBTABLE_TYPE1_HEADER_SIZE \
  52           ( GXV_STATETABLE_HEADER_SIZE + 2 )
  53
  54
  55   static void
  56   gxv_morx_subtable_type1_substitutionTable_load( FT_Bytes       table,
  57                                                   FT_Bytes       limit,
  58                                                   GXV_Validator  gxvalid )
  59   {
  60     FT_Bytes  p = table;
  61
  62     GXV_morx_subtable_type1_StateOptRecData  optdata =
  63       (GXV_morx_subtable_type1_StateOptRecData)gxvalid->xstatetable.optdata;
  64
  65
  66     GXV_LIMIT_CHECK( 2 );
  67     optdata->substitutionTable = FT_NEXT_USHORT( p );
  68   }
  69
  70
  71   static void
  72   gxv_morx_subtable_type1_subtable_setup( FT_ULong       table_size,
  73                                           FT_ULong       classTable,
  74                                           FT_ULong       stateArray,
  75                                           FT_ULong       entryTable,
  76                                           FT_ULong*      classTable_length_p,
  77                                           FT_ULong*      stateArray_length_p,
  78                                           FT_ULong*      entryTable_length_p,
  79                                           GXV_Validator  gxvalid )
  80   {
  81     FT_ULong  o[4];
  82     FT_ULong  *l[4];
  83     FT_ULong  buff[5];
  84
  85     GXV_morx_subtable_type1_StateOptRecData  optdata =
  86       (GXV_morx_subtable_type1_StateOptRecData)gxvalid->xstatetable.optdata;
  87
  88
  89     o[0] = classTable;
  90     o[1] = stateArray;
  91     o[2] = entryTable;
  92     o[3] = optdata->substitutionTable;
  93     l[0] = classTable_length_p;
  94     l[1] = stateArray_length_p;
  95     l[2] = entryTable_length_p;
  96     l[3] = &(optdata->substitutionTable_length);
  97
  98     gxv_set_length_by_ulong_offset( o, l, buff, 4, table_size, gxvalid );
  99   }
 100
 101
 102   static void
 103   gxv_morx_subtable_type1_entry_validate(
 104     FT_UShort                       state,
 105     FT_UShort                       flags,
 106     GXV_StateTable_GlyphOffsetCPtr  glyphOffset_p,
 107     FT_Bytes                        table,
 108     FT_Bytes                        limit,
 109     GXV_Validator                   gxvalid )
 110   {
 111 #ifdef GXV_LOAD_TRACE_VARS
 112     FT_UShort  setMark;
 113     FT_UShort  dontAdvance;
 114 #endif
 115     FT_UShort  reserved;
 116     FT_Short   markIndex;
 117     FT_Short   currentIndex;
 118
 119     GXV_morx_subtable_type1_StateOptRecData  optdata =
 120       (GXV_morx_subtable_type1_StateOptRecData)gxvalid->xstatetable.optdata;
 121
 122     FT_UNUSED( state );
 123     FT_UNUSED( table );
 124     FT_UNUSED( limit );
 125
 126
 127 #ifdef GXV_LOAD_TRACE_VARS
 128     setMark      = (FT_UShort)( ( flags >> 15 ) & 1 );
 129     dontAdvance  = (FT_UShort)( ( flags >> 14 ) & 1 );
 130 #endif
 131
 132     reserved = (FT_UShort)( flags & 0x3FFF );
 133
 134     markIndex    = (FT_Short)( glyphOffset_p->ul >> 16 );
 135     currentIndex = (FT_Short)( glyphOffset_p->ul       );
 136
 137     GXV_TRACE(( " setMark=%01d dontAdvance=%01d\n",
 138                 setMark, dontAdvance ));
 139
 140     if ( 0 < reserved )
 141     {
 142       GXV_TRACE(( " non-zero bits found in reserved range\n" ));
 143       GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA );
 144     }
 145
 146     GXV_TRACE(( "markIndex = %d, currentIndex = %d\n",
 147                 markIndex, currentIndex ));
 148
 149     if ( optdata->substitutionTable_num_lookupTables < markIndex + 1 )
 150       optdata->substitutionTable_num_lookupTables =
 151         (FT_Short)( markIndex + 1 );
 152
 153     if ( optdata->substitutionTable_num_lookupTables < currentIndex + 1 )
 154       optdata->substitutionTable_num_lookupTables =
 155         (FT_Short)( currentIndex + 1 );
 156   }
 157
 158
 159   static void
 160   gxv_morx_subtable_type1_LookupValue_validate( FT_UShort            glyph,
 161                                                 GXV_LookupValueCPtr  value_p,
 162                                                 GXV_Validator        gxvalid )
 163   {
 164     FT_UNUSED( glyph ); /* for the non-debugging case */
 165
 166     GXV_TRACE(( "morx subtable type1 subst.: %d -> %d\n", glyph, value_p->u ));
 167
 168     if ( value_p->u > gxvalid->face->num_glyphs )
 169       FT_INVALID_GLYPH_ID;
 170   }
 171
 172
 173   static GXV_LookupValueDesc
 174   gxv_morx_subtable_type1_LookupFmt4_transit(
 175     FT_UShort            relative_gindex,
 176     GXV_LookupValueCPtr  base_value_p,
 177     FT_Bytes             lookuptbl_limit,
 178     GXV_Validator        gxvalid )
 179   {
 180     FT_Bytes             p;
 181     FT_Bytes             limit;
 182     FT_UShort            offset;
 183     GXV_LookupValueDesc  value;
 184
 185     /* XXX: check range? */
 186     offset = (FT_UShort)( base_value_p->u +
 187                           relative_gindex * sizeof ( FT_UShort ) );
 188
 189     p     = gxvalid->lookuptbl_head + offset;
 190     limit = lookuptbl_limit;
 191
 192     GXV_LIMIT_CHECK ( 2 );
 193     value.u = FT_NEXT_USHORT( p );
 194
 195     return value;
 196   }
 197
 198
 199   /*
 200    * TODO: length should be limit?
 201    **/
 202   static void
 203   gxv_morx_subtable_type1_substitutionTable_validate( FT_Bytes       table,
 204                                                       FT_Bytes       limit,
 205                                                       GXV_Validator  gxvalid )
 206   {
 207     FT_Bytes   p = table;
 208     FT_UShort  i;
 209
 210     GXV_morx_subtable_type1_StateOptRecData  optdata =
 211       (GXV_morx_subtable_type1_StateOptRecData)gxvalid->xstatetable.optdata;
 212
 213
 214     /* TODO: calculate offset/length for each lookupTables */
 215     gxvalid->lookupval_sign   = GXV_LOOKUPVALUE_UNSIGNED;
 216     gxvalid->lookupval_func   = gxv_morx_subtable_type1_LookupValue_validate;
 217     gxvalid->lookupfmt4_trans = gxv_morx_subtable_type1_LookupFmt4_transit;
 218
 219     for ( i = 0; i < optdata->substitutionTable_num_lookupTables; i++ )
 220     {
 221       FT_ULong  offset;
 222
 223
 224       GXV_LIMIT_CHECK( 4 );
 225       offset = FT_NEXT_ULONG( p );
 226
 227       gxv_LookupTable_validate( table + offset, limit, gxvalid );
 228     }
 229
 230     /* TODO: overlapping of lookupTables in substitutionTable */
 231   }
 232
 233
 234   /*
 235    * subtable for Contextual glyph substitution is a modified StateTable.
 236    * In addition to classTable, stateArray, entryTable, the field
 237    * `substitutionTable' is added.
 238    */
 239   FT_LOCAL_DEF( void )
 240   gxv_morx_subtable_type1_validate( FT_Bytes       table,
 241                                     FT_Bytes       limit,
 242                                     GXV_Validator  gxvalid )
 243   {
 244     FT_Bytes  p = table;
 245
 246     GXV_morx_subtable_type1_StateOptRec  st_rec;
 247
 248
 249     GXV_NAME_ENTER( "morx chain subtable type1 (Contextual Glyph Subst)" );
 250
 251     GXV_LIMIT_CHECK( GXV_MORX_SUBTABLE_TYPE1_HEADER_SIZE );
 252
 253     st_rec.substitutionTable_num_lookupTables = 0;
 254
 255     gxvalid->xstatetable.optdata =
 256       &st_rec;
 257     gxvalid->xstatetable.optdata_load_func =
 258       gxv_morx_subtable_type1_substitutionTable_load;
 259     gxvalid->xstatetable.subtable_setup_func =
 260       gxv_morx_subtable_type1_subtable_setup;
 261     gxvalid->xstatetable.entry_glyphoffset_fmt =
 262       GXV_GLYPHOFFSET_ULONG;
 263     gxvalid->xstatetable.entry_validate_func =
 264       gxv_morx_subtable_type1_entry_validate;
 265
 266     gxv_XStateTable_validate( p, limit, gxvalid );
 267
 268     gxv_morx_subtable_type1_substitutionTable_validate(
 269       table + st_rec.substitutionTable,
 270       table + st_rec.substitutionTable + st_rec.substitutionTable_length,
 271       gxvalid );
 272
 273     GXV_EXIT;
 274   }
 275
 276
 277 /* END */