src/gxvalid/gxvlcar.c

   1 /****************************************************************************
   2  *
   3  * gxvlcar.c
   4  *
   5  *   TrueTypeGX/AAT lcar table validation (body).
   6  *
   7  * Copyright (C) 2004-2020 by
   8  * 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 "gxvalid.h"
  29 #include "gxvcommn.h"
  30
  31
  32   /**************************************************************************
  33    *
  34    * The macro FT_COMPONENT is used in trace mode.  It is an implicit
  35    * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log
  36    * messages during execution.
  37    */
  38 #undef  FT_COMPONENT
  39 #define FT_COMPONENT  gxvlcar
  40
  41
  42   /*************************************************************************/
  43   /*************************************************************************/
  44   /*****                                                               *****/
  45   /*****                      Data and Types                           *****/
  46   /*****                                                               *****/
  47   /*************************************************************************/
  48   /*************************************************************************/
  49
  50   typedef struct  GXV_lcar_DataRec_
  51   {
  52     FT_UShort  format;
  53
  54   } GXV_lcar_DataRec, *GXV_lcar_Data;
  55
  56
  57 #define GXV_LCAR_DATA( FIELD )  GXV_TABLE_DATA( lcar, FIELD )
  58
  59
  60   /*************************************************************************/
  61   /*************************************************************************/
  62   /*****                                                               *****/
  63   /*****                      UTILITY FUNCTIONS                        *****/
  64   /*****                                                               *****/
  65   /*************************************************************************/
  66   /*************************************************************************/
  67
  68   static void
  69   gxv_lcar_partial_validate( FT_Short       partial,
  70                              FT_UShort      glyph,
  71                              GXV_Validator  gxvalid )
  72   {
  73     GXV_NAME_ENTER( "partial" );
  74
  75     if ( GXV_LCAR_DATA( format ) != 1 )
  76       goto Exit;
  77
  78     gxv_ctlPoint_validate( glyph, (FT_UShort)partial, gxvalid );
  79
  80   Exit:
  81     GXV_EXIT;
  82   }
  83
  84
  85   static void
  86   gxv_lcar_LookupValue_validate( FT_UShort            glyph,
  87                                  GXV_LookupValueCPtr  value_p,
  88                                  GXV_Validator        gxvalid )
  89   {
  90     FT_Bytes   p     = gxvalid->root->base + value_p->u;
  91     FT_Bytes   limit = gxvalid->root->limit;
  92     FT_UShort  count;
  93     FT_Short   partial;
  94     FT_UShort  i;
  95
  96
  97     GXV_NAME_ENTER( "element in lookupTable" );
  98
  99     GXV_LIMIT_CHECK( 2 );
 100     count = FT_NEXT_USHORT( p );
 101
 102     GXV_LIMIT_CHECK( 2 * count );
 103     for ( i = 0; i < count; i++ )
 104     {
 105       partial = FT_NEXT_SHORT( p );
 106       gxv_lcar_partial_validate( partial, glyph, gxvalid );
 107     }
 108
 109     GXV_EXIT;
 110   }
 111
 112
 113   /*
 114     +------ lcar --------------------+
 115     |                                |
 116     |      +===============+         |
 117     |      | lookup header |         |
 118     |      +===============+         |
 119     |      | BinSrchHeader |         |
 120     |      +===============+         |
 121     |      | lastGlyph[0]  |         |
 122     |      +---------------+         |
 123     |      | firstGlyph[0] |         |  head of lcar sfnt table
 124     |      +---------------+         |             +
 125     |      | offset[0]     |    ->   |          offset            [byte]
 126     |      +===============+         |             +
 127     |      | lastGlyph[1]  |         | (glyphID - firstGlyph) * 2 [byte]
 128     |      +---------------+         |
 129     |      | firstGlyph[1] |         |
 130     |      +---------------+         |
 131     |      | offset[1]     |         |
 132     |      +===============+         |
 133     |                                |
 134     |       ....                     |
 135     |                                |
 136     |      16bit value array         |
 137     |      +===============+         |
 138     +------|     value     | <-------+
 139     |       ....
 140     |
 141     |
 142     |
 143     |
 144     |
 145     +---->  lcar values...handled by lcar callback function
 146   */
 147
 148   static GXV_LookupValueDesc
 149   gxv_lcar_LookupFmt4_transit( FT_UShort            relative_gindex,
 150                                GXV_LookupValueCPtr  base_value_p,
 151                                FT_Bytes             lookuptbl_limit,
 152                                GXV_Validator        gxvalid )
 153   {
 154     FT_Bytes             p;
 155     FT_Bytes             limit;
 156     FT_UShort            offset;
 157     GXV_LookupValueDesc  value;
 158
 159     FT_UNUSED( lookuptbl_limit );
 160
 161     /* XXX: check range? */
 162     offset = (FT_UShort)( base_value_p->u +
 163                           relative_gindex * sizeof ( FT_UShort ) );
 164     p      = gxvalid->root->base + offset;
 165     limit  = gxvalid->root->limit;
 166
 167     GXV_LIMIT_CHECK ( 2 );
 168     value.u = FT_NEXT_USHORT( p );
 169
 170     return value;
 171   }
 172
 173
 174   /*************************************************************************/
 175   /*************************************************************************/
 176   /*****                                                               *****/
 177   /*****                          lcar TABLE                           *****/
 178   /*****                                                               *****/
 179   /*************************************************************************/
 180   /*************************************************************************/
 181
 182   FT_LOCAL_DEF( void )
 183   gxv_lcar_validate( FT_Bytes      table,
 184                      FT_Face       face,
 185                      FT_Validator  ftvalid )
 186   {
 187     FT_Bytes          p     = table;
 188     FT_Bytes          limit = 0;
 189     GXV_ValidatorRec  gxvalidrec;
 190     GXV_Validator     gxvalid = &gxvalidrec;
 191
 192     GXV_lcar_DataRec  lcarrec;
 193     GXV_lcar_Data     lcar = &lcarrec;
 194
 195     FT_Fixed          version;
 196
 197
 198     gxvalid->root       = ftvalid;
 199     gxvalid->table_data = lcar;
 200     gxvalid->face       = face;
 201
 202     FT_TRACE3(( "validating `lcar' table\n" ));
 203     GXV_INIT;
 204
 205     GXV_LIMIT_CHECK( 4 + 2 );
 206     version = FT_NEXT_LONG( p );
 207     GXV_LCAR_DATA( format ) = FT_NEXT_USHORT( p );
 208
 209     if ( version != 0x00010000UL)
 210       FT_INVALID_FORMAT;
 211
 212     if ( GXV_LCAR_DATA( format ) > 1 )
 213       FT_INVALID_FORMAT;
 214
 215     gxvalid->lookupval_sign   = GXV_LOOKUPVALUE_UNSIGNED;
 216     gxvalid->lookupval_func   = gxv_lcar_LookupValue_validate;
 217     gxvalid->lookupfmt4_trans = gxv_lcar_LookupFmt4_transit;
 218     gxv_LookupTable_validate( p, limit, gxvalid );
 219
 220     FT_TRACE4(( "\n" ));
 221   }
 222
 223
 224 /* END */