gxvjust.c

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/***************************************************************************/
/*                                                                         */
/*  gxvjust.c                                                              */
/*                                                                         */
/*    TrueTypeGX/AAT just table validation (body).                         */
/*                                                                         */
/*  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 "gxvalid.h"
#include "gxvcommn.h"

#include FT_SFNT_NAMES_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_gxvjust

  /*
   * referred `just' table format specification:
   * http://developer.apple.com/fonts/TTRefMan/RM06/Chap6just.html
   * last updated 2000.
   * ----------------------------------------------
   * [JUST HEADER]: GXV_JUST_HEADER_SIZE
   * version     (fixed:  32bit) = 0x00010000
   * format      (uint16: 16bit) = 0 is only defined (2000)
   * horizOffset (uint16: 16bit)
   * vertOffset  (uint16: 16bit)
   * ----------------------------------------------
   */

  typedef struct  GXV_just_DataRec_
  {
    FT_UShort  wdc_offset_max;
    FT_UShort  wdc_offset_min;
    FT_UShort  pc_offset_max;
    FT_UShort  pc_offset_min;

  } GXV_just_DataRec, *GXV_just_Data;


#define  GXV_JUST_DATA( a )  GXV_TABLE_DATA( just, a )


  static void
  gxv_just_wdp_entry_validate( FT_Bytes       table,
                               FT_Bytes       limit,
                               GXV_Validator  valid )
  {
    FT_Bytes   p = table;
    FT_ULong   justClass;
    FT_Fixed   beforeGrowLimit;
    FT_Fixed   beforeShrinkGrowLimit;
    FT_Fixed   afterGrowLimit;
    FT_Fixed   afterShrinkGrowLimit;
    FT_UShort  growFlags;
    FT_UShort  shrinkFlags;


    GXV_LIMIT_CHECK( 4 + 4 + 4 + 4 + 4 + 2 + 2 );
    justClass             = FT_NEXT_ULONG( p );
    beforeGrowLimit       = FT_NEXT_ULONG( p );
    beforeShrinkGrowLimit = FT_NEXT_ULONG( p );
    afterGrowLimit        = FT_NEXT_ULONG( p );
    afterShrinkGrowLimit  = FT_NEXT_ULONG( p );
    growFlags             = FT_NEXT_USHORT( p );
    shrinkFlags           = FT_NEXT_USHORT( p );

    /* TODO: decode flags for human readability */

    valid->subtable_length = p - table;
  }


  static void
  gxv_just_wdc_entry_validate( FT_Bytes       table,
                               FT_Bytes       limit,
                               GXV_Validator  valid )
  {
    FT_Bytes  p = table;
    FT_ULong  count, i;


    GXV_LIMIT_CHECK( 4 );
    count = FT_NEXT_ULONG( p );
    for ( i = 0; i < count; i++ )
    {
      GXV_TRACE(( "validating wdc pair %d/%d\n", i + 1, count ));
      gxv_just_wdp_entry_validate( p, limit, valid );
      p += valid->subtable_length;
    }

    valid->subtable_length = p - table;
  }


  static void
  gxv_just_widthDeltaClusters_validate( FT_Bytes       table,
                                        FT_Bytes       limit,
                                        GXV_Validator  valid )
  {
    FT_Bytes  p         = table ;
    FT_Bytes  wdc_end   = table + GXV_JUST_DATA( wdc_offset_max );
    FT_UInt   i;


    GXV_NAME_ENTER( "just justDeltaClusters" );

    if ( limit <= wdc_end )
      FT_INVALID_OFFSET;

    for ( i = 0; p <= wdc_end; i++ )
    {
      gxv_just_wdc_entry_validate( p, limit, valid );
      p += valid->subtable_length;
    }

    valid->subtable_length = p - table;

    GXV_EXIT;
  }


  static void
  gxv_just_actSubrecord_type0_validate( FT_Bytes       table,
                                        FT_Bytes       limit,
                                        GXV_Validator  valid )
  {
    FT_Bytes   p = table;

    FT_Fixed   lowerLimit;
    FT_Fixed   upperLimit;

    FT_UShort  order;
    FT_UShort  decomposedCount;

    FT_UInt    i;


    GXV_LIMIT_CHECK( 4 + 4 + 2 + 2 );
    lowerLimit      = FT_NEXT_ULONG( p );
    upperLimit      = FT_NEXT_ULONG( p );
    order           = FT_NEXT_USHORT( p );
    decomposedCount = FT_NEXT_USHORT( p );

    for ( i = 0; i < decomposedCount; i++ )
    {
      FT_UShort glyphs;


      GXV_LIMIT_CHECK( 2 );
      glyphs = FT_NEXT_USHORT( p );
    }

    valid->subtable_length = p - table;
  }


  static void
  gxv_just_actSubrecord_type1_validate( FT_Bytes       table,
                                        FT_Bytes       limit,
                                        GXV_Validator  valid )
  {
    FT_Bytes   p = table;
    FT_UShort  addGlyph;


    GXV_LIMIT_CHECK( 2 );
    addGlyph = FT_NEXT_USHORT( p );

    valid->subtable_length = p - table;
  }


  static void
  gxv_just_actSubrecord_type2_validate( FT_Bytes       table,
                                        FT_Bytes       limit,
                                        GXV_Validator  valid )
  {
    FT_Bytes   p = table;
    FT_Fixed   substThreshhold; /* Apple misspelled "Threshhold" */
    FT_UShort  addGlyph;
    FT_UShort  substGlyph;


    GXV_LIMIT_CHECK( 4 + 2 + 2 );
    substThreshhold = FT_NEXT_ULONG( p );
    addGlyph        = FT_NEXT_USHORT( p );
    substGlyph      = FT_NEXT_USHORT( p );

    valid->subtable_length = p - table;
  }


  static void
  gxv_just_actSubrecord_type4_validate( FT_Bytes       table,
                                        FT_Bytes       limit,
                                        GXV_Validator  valid )
  {
    FT_Bytes  p = table;
    FT_ULong  variantsAxis;
    FT_Fixed  minimumLimit;
    FT_Fixed  noStretchValue;
    FT_Fixed  maximumLimit;


    GXV_LIMIT_CHECK( 4 + 4 + 4 + 4 );
    variantsAxis   = FT_NEXT_ULONG( p );
    minimumLimit   = FT_NEXT_ULONG( p );
    noStretchValue = FT_NEXT_ULONG( p );
    maximumLimit   = FT_NEXT_ULONG( p );

    valid->subtable_length = p - table;
  }


  static void
  gxv_just_actSubrecord_type5_validate( FT_Bytes       table,
                                        FT_Bytes       limit,
                                        GXV_Validator  valid )
  {
    FT_Bytes   p = table;
    FT_UShort  flags;
    FT_UShort  glyph;


    GXV_LIMIT_CHECK( 2 + 2 );
    flags = FT_NEXT_USHORT( p );
    glyph = FT_NEXT_USHORT( p );

    valid->subtable_length = p - table;
  }


  /* parse single actSubrecord */
  static void
  gxv_just_actSubrecord_validate( FT_Bytes       table,
                                  FT_Bytes       limit,
                                  GXV_Validator  valid )
  {
    FT_Bytes   p = table;
    FT_UShort  actionClass;
    FT_UShort  actionType;
    FT_ULong   actionLength;


    GXV_NAME_ENTER( "just actSubrecord" );

    GXV_LIMIT_CHECK( 2 + 2 + 4 );
    actionClass  = FT_NEXT_USHORT( p );
    actionType   = FT_NEXT_USHORT( p );
    actionLength = FT_NEXT_ULONG( p );

    if ( actionType == 0 )
      gxv_just_actSubrecord_type0_validate( p, limit, valid );
    else if ( actionType == 1 )
      gxv_just_actSubrecord_type1_validate( p, limit, valid );
    else if ( actionType == 2 )
      gxv_just_actSubrecord_type2_validate( p, limit, valid );
    else if ( actionType == 3 )
      ;                         /* Stretch glyph action: no actionData */
    else if ( actionType == 4 )
      gxv_just_actSubrecord_type4_validate( p, limit, valid );
    else if ( actionType == 5 )
      gxv_just_actSubrecord_type5_validate( p, limit, valid );
    else
      FT_INVALID_DATA;

    valid->subtable_length = actionLength;

    GXV_EXIT;
  }


  static void
  gxv_just_pcActionRecord_validate( FT_Bytes       table,
                                    FT_Bytes       limit,
                                    GXV_Validator  valid )
  {
    FT_Bytes  p = table;
    FT_ULong  actionCount;
    FT_ULong  i;


    GXV_LIMIT_CHECK( 4 );
    actionCount = FT_NEXT_ULONG( p );
    GXV_TRACE(( "actionCount = %d\n", actionCount ));

    for ( i = 0; i < actionCount; i++ )
    {
      gxv_just_actSubrecord_validate( p, limit, valid );
      p += valid->subtable_length;
    }