src/gxvalid/gxvmort4.c

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  gxvmort4.c                                                             */
   4 /*                                                                         */
   5 /*    TrueTypeGX/AAT mort table validation                                 */
   6 /*    body for type4 (Non-Contextual Glyph Substitution) subtable.         */
   7 /*                                                                         */
   8 /*  Copyright 2005 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   static void
  42   gxv_mort_subtable_type4_lookupval_validate( FT_UShort            glyph,
  43                                               GXV_LookupValueCPtr  value_p,
  44                                               GXV_Validator        gxvalid )
  45   {
  46     FT_UNUSED( glyph );
  47
  48     gxv_glyphid_validate( value_p->u, gxvalid );
  49   }
  50
  51   /*
  52     +===============+ --------+
  53     | lookup header |         |
  54     +===============+         |
  55     | BinSrchHeader |         |
  56     +===============+         |
  57     | lastGlyph[0]  |         |
  58     +---------------+         |
  59     | firstGlyph[0] |         |    head of lookup table
  60     +---------------+         |             +
  61     | offset[0]     |    ->   |          offset            [byte]
  62     +===============+         |             +
  63     | lastGlyph[1]  |         | (glyphID - firstGlyph) * 2 [byte]
  64     +---------------+         |
  65     | firstGlyph[1] |         |
  66     +---------------+         |
  67     | offset[1]     |         |
  68     +===============+         |
  69                               |
  70      ....                     |
  71                               |
  72     16bit value array         |
  73     +===============+         |
  74     |     value     | <-------+
  75      ....
  76   */
  77
  78   static GXV_LookupValueDesc
  79   gxv_mort_subtable_type4_lookupfmt4_transit(
  80     FT_UShort            relative_gindex,
  81     GXV_LookupValueCPtr  base_value_p,
  82     FT_Bytes             lookuptbl_limit,
  83     GXV_Validator        gxvalid )
  84   {
  85     FT_Bytes             p;
  86     FT_Bytes             limit;
  87     FT_UShort            offset;
  88     GXV_LookupValueDesc  value;
  89
  90     /* XXX: check range? */
  91     offset = (FT_UShort)( base_value_p->u +
  92                           relative_gindex * sizeof ( FT_UShort ) );
  93
  94     p     = gxvalid->lookuptbl_head + offset;
  95     limit = lookuptbl_limit;
  96
  97     GXV_LIMIT_CHECK( 2 );
  98     value.u = FT_NEXT_USHORT( p );
  99
 100     return value;
 101   }
 102
 103
 104   FT_LOCAL_DEF( void )
 105   gxv_mort_subtable_type4_validate( FT_Bytes       table,
 106                                     FT_Bytes       limit,
 107                                     GXV_Validator  gxvalid )
 108   {
 109     FT_Bytes  p = table;
 110
 111
 112     GXV_NAME_ENTER( "mort chain subtable type4 "
 113                     "(Non-Contextual Glyph Substitution)" );
 114
 115     gxvalid->lookupval_sign   = GXV_LOOKUPVALUE_UNSIGNED;
 116     gxvalid->lookupval_func   = gxv_mort_subtable_type4_lookupval_validate;
 117     gxvalid->lookupfmt4_trans = gxv_mort_subtable_type4_lookupfmt4_transit;
 118
 119     gxv_LookupTable_validate( p, limit, gxvalid );
 120
 121     GXV_EXIT;
 122   }
 123
 124
 125 /* END */