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      1 /***************************************************************************/
      2 /*                                                                         */
      3 /*  gxvmort4.c                                                             */
      4 /*                                                                         */
      5 /*    TrueTypeGX/AAT mort table validation                                 */
      6 /*    body for type4 (Non-Contextual Glyph Substitution) subtable.         */
      7 /*                                                                         */
      8 /*  Copyright 2005-2018 by                                                 */
      9 /*  suzuki toshiya, Masatake YAMATO, Red Hat K.K.,                         */
     10 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
     11 /*                                                                         */
     12 /*  This file is part of the FreeType project, and may only be used,       */
     13 /*  modified, and distributed under the terms of the FreeType project      */
     14 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
     15 /*  this file you indicate that you have read the license and              */
     16 /*  understand and accept it fully.                                        */
     17 /*                                                                         */
     18 /***************************************************************************/
     19 
     20 /***************************************************************************/
     21 /*                                                                         */
     22 /* gxvalid is derived from both gxlayout module and otvalid module.        */
     23 /* Development of gxlayout is supported by the Information-technology      */
     24 /* Promotion Agency(IPA), Japan.                                           */
     25 /*                                                                         */
     26 /***************************************************************************/
     27 
     28 
     29 #include "gxvmort.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  trace_gxvmort
     40 
     41 
     42   static void
     43   gxv_mort_subtable_type4_lookupval_validate( FT_UShort            glyph,
     44                                               GXV_LookupValueCPtr  value_p,
     45                                               GXV_Validator        gxvalid )
     46   {
     47     FT_UNUSED( glyph );
     48 
     49     gxv_glyphid_validate( value_p->u, gxvalid );
     50   }
     51 
     52   /*
     53     +===============+ --------+
     54     | lookup header |         |
     55     +===============+         |
     56     | BinSrchHeader |         |
     57     +===============+         |
     58     | lastGlyph[0]  |         |
     59     +---------------+         |
     60     | firstGlyph[0] |         |    head of lookup table
     61     +---------------+         |             +
     62     | offset[0]     |    ->   |          offset            [byte]
     63     +===============+         |             +
     64     | lastGlyph[1]  |         | (glyphID - firstGlyph) * 2 [byte]
     65     +---------------+         |
     66     | firstGlyph[1] |         |
     67     +---------------+         |
     68     | offset[1]     |         |
     69     +===============+         |
     70                               |
     71      ....                     |
     72                               |
     73     16bit value array         |
     74     +===============+         |
     75     |     value     | <-------+
     76      ....
     77   */
     78 
     79   static GXV_LookupValueDesc
     80   gxv_mort_subtable_type4_lookupfmt4_transit(
     81     FT_UShort            relative_gindex,
     82     GXV_LookupValueCPtr  base_value_p,
     83     FT_Bytes             lookuptbl_limit,
     84     GXV_Validator        gxvalid )
     85   {
     86     FT_Bytes             p;
     87     FT_Bytes             limit;
     88     FT_UShort            offset;
     89     GXV_LookupValueDesc  value;
     90 
     91     /* XXX: check range? */
     92     offset = (FT_UShort)( base_value_p->u +
     93                           relative_gindex * sizeof ( FT_UShort ) );
     94 
     95     p     = gxvalid->lookuptbl_head + offset;
     96     limit = lookuptbl_limit;
     97 
     98     GXV_LIMIT_CHECK( 2 );
     99     value.u = FT_NEXT_USHORT( p );
    100 
    101     return value;
    102   }
    103 
    104 
    105   FT_LOCAL_DEF( void )
    106   gxv_mort_subtable_type4_validate( FT_Bytes       table,
    107                                     FT_Bytes       limit,
    108                                     GXV_Validator  gxvalid )
    109   {
    110     FT_Bytes  p = table;
    111 
    112 
    113     GXV_NAME_ENTER( "mort chain subtable type4 "
    114                     "(Non-Contextual Glyph Substitution)" );
    115 
    116     gxvalid->lookupval_sign   = GXV_LOOKUPVALUE_UNSIGNED;
    117     gxvalid->lookupval_func   = gxv_mort_subtable_type4_lookupval_validate;
    118     gxvalid->lookupfmt4_trans = gxv_mort_subtable_type4_lookupfmt4_transit;
    119 
    120     gxv_LookupTable_validate( p, limit, gxvalid );
    121 
    122     GXV_EXIT;
    123   }
    124 
    125 
    126 /* END */
    127