gxvmort4.c

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/***************************************************************************/
/*                                                                         */
/*  gxvmort4.c                                                             */
/*                                                                         */
/*    TrueTypeGX/AAT mort table validation                                 */
/*    body for type4 (Non-Contextual Glyph Substitution) subtable.         */
/*                                                                         */
/*  Copyright 2005-2018 by                                                 */
/*  suzuki toshiya, Masatake YAMATO, Red Hat K.K.,                         */
/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
/*                                                                         */
/*  This file is part of the FreeType project, and may only be used,       */
/*  modified, and distributed under the terms of the FreeType project      */
/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
/*  this file you indicate that you have read the license and              */
/*  understand and accept it fully.                                        */
/*                                                                         */
/***************************************************************************/
 
/***************************************************************************/
/*                                                                         */
/* gxvalid is derived from both gxlayout module and otvalid module.        */
/* Development of gxlayout is supported by the Information-technology      */
/* Promotion Agency(IPA), Japan.                                           */
/*                                                                         */
/***************************************************************************/
 
 
#include "gxvmort.h"
 
 
  /*************************************************************************/
  /*                                                                       */
  /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
  /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
  /* messages during execution.                                            */
  /*                                                                       */
#undef  FT_COMPONENT
#define FT_COMPONENT  trace_gxvmort
 
 
  static void
  gxv_mort_subtable_type4_lookupval_validate( FT_UShort            glyph,
                                              GXV_LookupValueCPtr  value_p,
                                              GXV_Validator        gxvalid )
  {
    FT_UNUSED( glyph );
 
    gxv_glyphid_validate( value_p->u, gxvalid );
  }
 
  /*
    +===============+ --------+
    | lookup header |         |
    +===============+         |
    | BinSrchHeader |         |
    +===============+         |
    | lastGlyph[0]  |         |
    +---------------+         |
    | firstGlyph[0] |         |    head of lookup table
    +---------------+         |             +
    | offset[0]     |    ->   |          offset            [byte]
    +===============+         |             +
    | lastGlyph[1]  |         | (glyphID - firstGlyph) * 2 [byte]
    +---------------+         |
    | firstGlyph[1] |         |
    +---------------+         |
    | offset[1]     |         |
    +===============+         |
                              |
     ....                     |
                              |
    16bit value array         |
    +===============+         |
    |     value     | <-------+
     ....
  */
 
  static GXV_LookupValueDesc
  gxv_mort_subtable_type4_lookupfmt4_transit(
    FT_UShort            relative_gindex,
    GXV_LookupValueCPtr  base_value_p,
    FT_Bytes             lookuptbl_limit,
    GXV_Validator        gxvalid )
  {
    FT_Bytes             p;
    FT_Bytes             limit;
    FT_UShort            offset;
    GXV_LookupValueDesc  value;
 
    /* XXX: check range? */
    offset = (FT_UShort)( base_value_p->u +
                          relative_gindex * sizeof ( FT_UShort ) );
 
    p     = gxvalid->lookuptbl_head + offset;
    limit = lookuptbl_limit;
 
    GXV_LIMIT_CHECK( 2 );
    value.u = FT_NEXT_USHORT( p );
 
    return value;
  }
 
 
  FT_LOCAL_DEF( void )
  gxv_mort_subtable_type4_validate( FT_Bytes       table,
                                    FT_Bytes       limit,
                                    GXV_Validator  gxvalid )
  {
    FT_Bytes  p = table;
 
 
    GXV_NAME_ENTER( "mort chain subtable type4 "
                    "(Non-Contextual Glyph Substitution)" );
 
    gxvalid->lookupval_sign   = GXV_LOOKUPVALUE_UNSIGNED;
    gxvalid->lookupval_func   = gxv_mort_subtable_type4_lookupval_validate;
    gxvalid->lookupfmt4_trans = gxv_mort_subtable_type4_lookupfmt4_transit;
 
    gxv_LookupTable_validate( p, limit, gxvalid );
 
    GXV_EXIT;
  }
 
 
/* END */