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00001 /***************************************************************************/
00002 /*                                                                         */
00003 /*  gxvmort2.c                                                             */
00004 /*                                                                         */
00005 /*    TrueTypeGX/AAT mort table validation                                 */
00006 /*    body for type2 (Ligature Substitution) subtable.                     */
00007 /*                                                                         */
00008 /*  Copyright 2005 by suzuki toshiya, Masatake YAMATO, Red Hat K.K.,       */
00009 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
00010 /*                                                                         */
00011 /*  This file is part of the FreeType project, and may only be used,       */
00012 /*  modified, and distributed under the terms of the FreeType project      */
00013 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
00014 /*  this file you indicate that you have read the license and              */
00015 /*  understand and accept it fully.                                        */
00016 /*                                                                         */
00017 /***************************************************************************/
00018 
00019 /***************************************************************************/
00020 /*                                                                         */
00021 /* gxvalid is derived from both gxlayout module and otvalid module.        */
00022 /* Development of gxlayout is supported by the Information-technology      */
00023 /* Promotion Agency(IPA), Japan.                                           */
00024 /*                                                                         */
00025 /***************************************************************************/
00026 
00027 
00028 #include "gxvmort.h"
00029 
00030 
00031   /*************************************************************************/
00032   /*                                                                       */
00033   /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
00034   /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
00035   /* messages during execution.                                            */
00036   /*                                                                       */
00037 #undef  FT_COMPONENT
00038 #define FT_COMPONENT  trace_gxvmort
00039 
00040 
00041   typedef struct  GXV_mort_subtable_type2_StateOptRec_
00042   {
00043     FT_UShort  ligActionTable;
00044     FT_UShort  componentTable;
00045     FT_UShort  ligatureTable;
00046     FT_UShort  ligActionTable_length;
00047     FT_UShort  componentTable_length;
00048     FT_UShort  ligatureTable_length;
00049 
00050   }  GXV_mort_subtable_type2_StateOptRec,
00051     *GXV_mort_subtable_type2_StateOptRecData;
00052 
00053 #define GXV_MORT_SUBTABLE_TYPE2_HEADER_SIZE \
00054           ( GXV_STATETABLE_HEADER_SIZE + 2 + 2 + 2 )
00055 
00056 
00057   static void
00058   gxv_mort_subtable_type2_opttable_load( FT_Bytes       table,
00059                                          FT_Bytes       limit,
00060                                          GXV_Validator  valid )
00061   {
00062     FT_Bytes p = table;
00063     GXV_mort_subtable_type2_StateOptRecData  optdata =
00064       (GXV_mort_subtable_type2_StateOptRecData)valid->statetable.optdata;
00065 
00066 
00067     GXV_LIMIT_CHECK( 2 + 2 + 2 );
00068     optdata->ligActionTable = FT_NEXT_USHORT( p );
00069     optdata->componentTable = FT_NEXT_USHORT( p );
00070     optdata->ligatureTable  = FT_NEXT_USHORT( p );
00071 
00072     GXV_TRACE(( "offset to ligActionTable=0x%04x\n",
00073                 optdata->ligActionTable ));
00074     GXV_TRACE(( "offset to componentTable=0x%04x\n",
00075                 optdata->componentTable ));
00076     GXV_TRACE(( "offset to ligatureTable=0x%04x\n",
00077                 optdata->ligatureTable ));
00078   }
00079 
00080 
00081   static void
00082   gxv_mort_subtable_type2_subtable_setup( FT_UShort      table_size,
00083                                           FT_UShort      classTable,
00084                                           FT_UShort      stateArray,
00085                                           FT_UShort      entryTable,
00086                                           FT_UShort      *classTable_length_p,
00087                                           FT_UShort      *stateArray_length_p,
00088                                           FT_UShort      *entryTable_length_p,
00089                                           GXV_Validator  valid )
00090   {
00091     FT_UShort  o[6];
00092     FT_UShort  *l[6];
00093     FT_UShort  buff[7];
00094 
00095     GXV_mort_subtable_type2_StateOptRecData  optdata =
00096       (GXV_mort_subtable_type2_StateOptRecData)valid->statetable.optdata;
00097 
00098 
00099     GXV_NAME_ENTER( "subtable boundaries setup" );
00100 
00101     o[0] = classTable;
00102     o[1] = stateArray;
00103     o[2] = entryTable;
00104     o[3] = optdata->ligActionTable;
00105     o[4] = optdata->componentTable;
00106     o[5] = optdata->ligatureTable;
00107     l[0] = classTable_length_p;
00108     l[1] = stateArray_length_p;
00109     l[2] = entryTable_length_p;
00110     l[3] = &(optdata->ligActionTable_length);
00111     l[4] = &(optdata->componentTable_length);
00112     l[5] = &(optdata->ligatureTable_length);
00113 
00114     gxv_set_length_by_ushort_offset( o, l, buff, 6, table_size, valid );
00115 
00116     GXV_TRACE(( "classTable: offset=0x%04x length=0x%04x\n",
00117                 classTable, *classTable_length_p ));
00118     GXV_TRACE(( "stateArray: offset=0x%04x length=0x%04x\n",
00119                 stateArray, *stateArray_length_p ));
00120     GXV_TRACE(( "entryTable: offset=0x%04x length=0x%04x\n",
00121                 entryTable, *entryTable_length_p ));
00122     GXV_TRACE(( "ligActionTable: offset=0x%04x length=0x%04x\n",
00123                 optdata->ligActionTable,
00124                 optdata->ligActionTable_length ));
00125     GXV_TRACE(( "componentTable: offset=0x%04x length=0x%04x\n",
00126                 optdata->componentTable,
00127                 optdata->componentTable_length ));
00128     GXV_TRACE(( "ligatureTable:  offset=0x%04x length=0x%04x\n",
00129                 optdata->ligatureTable,
00130                 optdata->ligatureTable_length ));
00131 
00132     GXV_EXIT;
00133   }
00134 
00135 
00136   static void
00137   gxv_mort_subtable_type2_ligActionOffset_validate(
00138     FT_Bytes       table,
00139     FT_UShort      ligActionOffset,
00140     GXV_Validator  valid )
00141   {
00142     /* access ligActionTable */
00143     GXV_mort_subtable_type2_StateOptRecData  optdata =
00144       (GXV_mort_subtable_type2_StateOptRecData)valid->statetable.optdata;
00145 
00146     FT_Bytes lat_base  = table + optdata->ligActionTable;
00147     FT_Bytes p         = table + ligActionOffset;
00148     FT_Bytes lat_limit = lat_base + optdata->ligActionTable;
00149 
00150 
00151     GXV_32BIT_ALIGNMENT_VALIDATE( ligActionOffset );
00152     if ( p < lat_base )
00153     {
00154       GXV_TRACE(( "too short offset 0x%04x: p < lat_base (%d byte rewind)\n",
00155                   ligActionOffset, lat_base - p ));
00156 
00157       /* FontValidator, ftxvalidator, ftxdumperfuser warn but continue */
00158       if ( valid->root->level >= FT_VALIDATE_PARANOID )
00159         FT_INVALID_OFFSET;
00160     }
00161     else if ( lat_limit < p )
00162     {
00163       GXV_TRACE(( "too large offset 0x%04x: lat_limit < p (%d byte overrun)\n",
00164                   ligActionOffset, p - lat_limit ));
00165 
00166       /* FontValidator, ftxvalidator, ftxdumperfuser warn but continue */
00167       if ( valid->root->level >= FT_VALIDATE_PARANOID )
00168         FT_INVALID_OFFSET;
00169     }
00170     else
00171     {
00172       /* validate entry in ligActionTable */
00173       FT_ULong   lig_action;
00174       FT_UShort  last;
00175       FT_UShort  store;
00176       FT_ULong   offset;
00177 
00178 
00179       lig_action = FT_NEXT_ULONG( p );
00180       last   = (FT_UShort)( ( lig_action >> 31 ) & 1 );
00181       store  = (FT_UShort)( ( lig_action >> 30 ) & 1 );
00182 
00183       offset = lig_action & 0x3FFFFFFFUL;
00184     }
00185   }
00186 
00187 
00188   static void
00189   gxv_mort_subtable_type2_entry_validate(
00190     FT_Byte                         state,
00191     FT_UShort                       flags,
00192     GXV_StateTable_GlyphOffsetCPtr  glyphOffset_p,
00193     FT_Bytes                        table,
00194     FT_Bytes                        limit,
00195     GXV_Validator                   valid )
00196   {
00197     FT_UShort setComponent;
00198     FT_UShort dontAdvance;
00199     FT_UShort offset;
00200 
00201     FT_UNUSED( state );
00202     FT_UNUSED( glyphOffset_p );
00203     FT_UNUSED( limit );
00204 
00205 
00206     setComponent = (FT_UShort)( ( flags >> 15 ) & 1 );
00207     dontAdvance  = (FT_UShort)( ( flags >> 14 ) & 1 );
00208 
00209     offset = (FT_UShort)( flags & 0x3FFFU );
00210 
00211     if ( 0 < offset )
00212       gxv_mort_subtable_type2_ligActionOffset_validate( table, offset,
00213                                                         valid );
00214   }
00215 
00216 
00217   static void
00218   gxv_mort_subtable_type2_ligatureTable_validate( FT_Bytes       table,
00219                                                   GXV_Validator  valid )
00220   {
00221     GXV_mort_subtable_type2_StateOptRecData  optdata =
00222       (GXV_mort_subtable_type2_StateOptRecData)valid->statetable.optdata;
00223 
00224     FT_Bytes p     = table + optdata->ligatureTable;
00225     FT_Bytes limit = table + optdata->ligatureTable
00226                            + optdata->ligatureTable_length;
00227 
00228 
00229     GXV_NAME_ENTER( "mort chain subtable type2 - substitutionTable" );
00230     if ( 0 != optdata->ligatureTable )
00231     {
00232       /* Apple does not give specification of ligatureTable format */
00233       while ( p < limit )
00234       {
00235         FT_UShort  lig_gid;
00236 
00237 
00238         GXV_LIMIT_CHECK( 2 );
00239         lig_gid = FT_NEXT_USHORT( p );
00240       }
00241     }
00242     GXV_EXIT;
00243   }
00244 
00245 
00246   FT_LOCAL_DEF( void )
00247   gxv_mort_subtable_type2_validate( FT_Bytes       table,
00248                                     FT_Bytes       limit,
00249                                     GXV_Validator  valid )
00250   {
00251     FT_Bytes  p = table;
00252 
00253     GXV_mort_subtable_type2_StateOptRec  lig_rec;
00254 
00255 
00256     GXV_NAME_ENTER( "mort chain subtable type2 (Ligature Substitution)" );
00257 
00258     GXV_LIMIT_CHECK( GXV_MORT_SUBTABLE_TYPE2_HEADER_SIZE );
00259 
00260     valid->statetable.optdata =
00261       &lig_rec;
00262     valid->statetable.optdata_load_func =
00263       gxv_mort_subtable_type2_opttable_load;
00264     valid->statetable.subtable_setup_func =
00265       gxv_mort_subtable_type2_subtable_setup;
00266     valid->statetable.entry_glyphoffset_fmt =
00267       GXV_GLYPHOFFSET_NONE;
00268     valid->statetable.entry_validate_func =
00269       gxv_mort_subtable_type2_entry_validate;
00270 
00271     gxv_StateTable_validate( p, limit, valid );
00272 
00273     p += valid->subtable_length;
00274     gxv_mort_subtable_type2_ligatureTable_validate( table, valid );
00275 
00276     valid->subtable_length = p - table;
00277 
00278     GXV_EXIT;
00279   }
00280 
00281 
00282 /* END */
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