text: ﻿/***************************************************************************/
  /*                                                                         */
  /*  gxvmort4.c                                                             */
  /*                                                                         */
  /*    TrueTypeGX/AAT mort table validation                                 */
  /*    body for type4 (Non-Contextual Glyph Substitution) subtable.         */
  /*                                                                         */
  /*  Copyright 2005 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        valid )
    {
      FT_UNUSED( glyph );
  
      gxv_glyphid_validate( value_p->u, valid );
    }
  
    /*
      +===============+ --------+
      | 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        valid )
    {
      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     = valid->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  valid )
    {
      FT_Bytes  p = table;
  
  
      GXV_NAME_ENTER( "mort chain subtable type4 "
                      "(Non-Contextual Glyph Substitution)" );
  
      valid->lookupval_sign   = GXV_LOOKUPVALUE_UNSIGNED;
      valid->lookupval_func   = gxv_mort_subtable_type4_lookupval_validate;
      valid->lookupfmt4_trans = gxv_mort_subtable_type4_lookupfmt4_transit;
  
      gxv_LookupTable_validate( p, limit, valid );
  
      GXV_EXIT;
    }
  
  
  /* END */
  