harfbuzz-gsub.c

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  HB_SubRule*  sr;


  if ( srs->SubRule )
  {
    count = srs->SubRuleCount;
    sr    = srs->SubRule;

    for ( n = 0; n < count; n++ )
      Free_SubRule( &sr[n] );

    FREE( sr );
  }
}


/* ContextSubstFormat1 */

static HB_Error  Load_ContextSubst1( HB_ContextSubstFormat1*  csf1,
				     HB_Stream                 stream )
{
  HB_Error error;

  HB_UShort        n = 0, m, count;
  HB_UInt         cur_offset, new_offset, base_offset;

  HB_SubRuleSet*  srs;


  base_offset = FILE_Pos() - 2L;

  if ( ACCESS_Frame( 2L ) )
    return error;

  new_offset = GET_UShort() + base_offset;

  FORGET_Frame();

  cur_offset = FILE_Pos();
  if ( FILE_Seek( new_offset ) ||
       ( error = _HB_OPEN_Load_Coverage( &csf1->Coverage, stream ) ) != HB_Err_Ok )
    return error;
  (void)FILE_Seek( cur_offset );

  if ( ACCESS_Frame( 2L ) )
    goto Fail2;

  count = csf1->SubRuleSetCount = GET_UShort();

  FORGET_Frame();

  csf1->SubRuleSet = NULL;

  if ( ALLOC_ARRAY( csf1->SubRuleSet, count, HB_SubRuleSet ) )
    goto Fail2;

  srs = csf1->SubRuleSet;

  for ( n = 0; n < count; n++ )
  {
    if ( ACCESS_Frame( 2L ) )
      goto Fail1;

    new_offset = GET_UShort() + base_offset;

    FORGET_Frame();

    cur_offset = FILE_Pos();
    if ( FILE_Seek( new_offset ) ||
	 ( error = Load_SubRuleSet( &srs[n], stream ) ) != HB_Err_Ok )
      goto Fail1;
    (void)FILE_Seek( cur_offset );
  }

  return HB_Err_Ok;

Fail1:
  for ( m = 0; m < n; m++ )
    Free_SubRuleSet( &srs[m] );

  FREE( srs );

Fail2:
  _HB_OPEN_Free_Coverage( &csf1->Coverage );
  return error;
}


static void  Free_ContextSubst1( HB_ContextSubstFormat1* csf1 )
{
  HB_UShort        n, count;

  HB_SubRuleSet*  srs;


  if ( csf1->SubRuleSet )
  {
    count = csf1->SubRuleSetCount;
    srs   = csf1->SubRuleSet;

    for ( n = 0; n < count; n++ )
      Free_SubRuleSet( &srs[n] );

    FREE( srs );
  }

  _HB_OPEN_Free_Coverage( &csf1->Coverage );
}


/* SubClassRule */

static HB_Error  Load_SubClassRule( HB_ContextSubstFormat2*  csf2,
				    HB_SubClassRule*         scr,
				    HB_Stream                 stream )
{
  HB_Error error;

  HB_UShort               n, count;

  HB_UShort*              c;
  HB_SubstLookupRecord*  slr;
  HB_Bool*                d;


  if ( ACCESS_Frame( 4L ) )
    return error;

  scr->GlyphCount = GET_UShort();
  scr->SubstCount = GET_UShort();

  if ( scr->GlyphCount > csf2->MaxContextLength )
    csf2->MaxContextLength = scr->GlyphCount;

  FORGET_Frame();

  scr->Class = NULL;

  count = scr->GlyphCount - 1;        /* only GlyphCount - 1 elements */

  if ( ALLOC_ARRAY( scr->Class, count, HB_UShort ) )
    return error;

  c = scr->Class;
  d = csf2->ClassDef.Defined;

  if ( ACCESS_Frame( count * 2L ) )
    goto Fail2;

  for ( n = 0; n < count; n++ )
  {
    c[n] = GET_UShort();

    /* We check whether the specific class is used at all.  If not,
       class 0 is used instead.                                     */
    if ( !d[c[n]] )
      c[n] = 0;
  }

  FORGET_Frame();

  scr->SubstLookupRecord = NULL;

  count = scr->SubstCount;

  if ( ALLOC_ARRAY( scr->SubstLookupRecord, count, HB_SubstLookupRecord ) )
    goto Fail2;

  slr = scr->SubstLookupRecord;

  if ( ACCESS_Frame( count * 4L ) )
    goto Fail1;

  for ( n = 0; n < count; n++ )
  {
    slr[n].SequenceIndex   = GET_UShort();
    slr[n].LookupListIndex = GET_UShort();
  }

  FORGET_Frame();

  return HB_Err_Ok;

Fail1:
  FREE( slr );

Fail2:
  FREE( c );
  return error;
}


static void  Free_SubClassRule( HB_SubClassRule*  scr )
{
  FREE( scr->SubstLookupRecord );
  FREE( scr->Class );
}


/* SubClassSet */

static HB_Error  Load_SubClassSet( HB_ContextSubstFormat2*  csf2,
				   HB_SubClassSet*          scs,
				   HB_Stream                 stream )
{
  HB_Error error;

  HB_UShort          n = 0, m, count;
  HB_UInt           cur_offset, new_offset, base_offset;

  HB_SubClassRule*  scr;


  base_offset = FILE_Pos();

  if ( ACCESS_Frame( 2L ) )
    return error;

  count = scs->SubClassRuleCount = GET_UShort();

  FORGET_Frame();

  scs->SubClassRule = NULL;

  if ( ALLOC_ARRAY( scs->SubClassRule, count, HB_SubClassRule ) )
    return error;

  scr = scs->SubClassRule;

  for ( n = 0; n < count; n++ )
  {
    if ( ACCESS_Frame( 2L ) )
      goto Fail;

    new_offset = GET_UShort() + base_offset;

    FORGET_Frame();

    cur_offset = FILE_Pos();
    if ( FILE_Seek( new_offset ) ||
	 ( error = Load_SubClassRule( csf2, &scr[n],
				      stream ) ) != HB_Err_Ok )
      goto Fail;
    (void)FILE_Seek( cur_offset );
  }

  return HB_Err_Ok;

Fail:
  for ( m = 0; m < n; m++ )
    Free_SubClassRule( &scr[m] );

  FREE( scr );
  return error;
}


static void  Free_SubClassSet( HB_SubClassSet*  scs )
{
  HB_UShort          n, count;

  HB_SubClassRule*  scr;


  if ( scs->SubClassRule )
  {
    count = scs->SubClassRuleCount;
    scr   = scs->SubClassRule;

    for ( n = 0; n < count; n++ )
      Free_SubClassRule( &scr[n] );

    FREE( scr );
  }
}


/* ContextSubstFormat2 */

static HB_Error  Load_ContextSubst2( HB_ContextSubstFormat2*  csf2,
				     HB_Stream                 stream )
{
  HB_Error error;

  HB_UShort         n = 0, m, count;
  HB_UInt          cur_offset, new_offset, base_offset;

  HB_SubClassSet*  scs;


  base_offset = FILE_Pos() - 2;

  if ( ACCESS_Frame( 2L ) )
    return error;

  new_offset = GET_UShort() + base_offset;

  FORGET_Frame();

  cur_offset = FILE_Pos();
  if ( FILE_Seek( new_offset ) ||
       ( error = _HB_OPEN_Load_Coverage( &csf2->Coverage, stream ) ) != HB_Err_Ok )
    return error;
  (void)FILE_Seek( cur_offset );

  if ( ACCESS_Frame( 4L ) )
    goto Fail3;

  new_offset = GET_UShort() + base_offset;

  /* `SubClassSetCount' is the upper limit for class values, thus we
     read it now to make an additional safety check.                 */

  count = csf2->SubClassSetCount = GET_UShort();

  FORGET_Frame();

  cur_offset = FILE_Pos();
  if ( FILE_Seek( new_offset ) ||
       ( error = _HB_OPEN_Load_ClassDefinition( &csf2->ClassDef, count,
				       stream ) ) != HB_Err_Ok )
    goto Fail3;
  (void)FILE_Seek( cur_offset );

  csf2->SubClassSet      = NULL;
  csf2->MaxContextLength = 0;

  if ( ALLOC_ARRAY( csf2->SubClassSet, count, HB_SubClassSet ) )
    goto Fail2;

  scs = csf2->SubClassSet;

  for ( n = 0; n < count; n++ )
  {
    if ( ACCESS_Frame( 2L ) )
      goto Fail1;

    new_offset = GET_UShort() + base_offset;

    FORGET_Frame();

    if ( new_offset != base_offset )      /* not a NULL offset */
    {
      cur_offset = FILE_Pos();
      if ( FILE_Seek( new_offset ) ||
	   ( error = Load_SubClassSet( csf2, &scs[n],
				       stream ) ) != HB_Err_Ok )
	goto Fail1;
      (void)FILE_Seek( cur_offset );
    }
    else
    {
      /* we create a SubClassSet table with no entries */

      csf2->SubClassSet[n].SubClassRuleCount = 0;
      csf2->SubClassSet[n].SubClassRule      = NULL;
    }
  }

  return HB_Err_Ok;

Fail1:
  for ( m = 0; m < n; m++ )
    Free_SubClassSet( &scs[m] );

  FREE( scs );

Fail2:
  _HB_OPEN_Free_ClassDefinition( &csf2->ClassDef );

Fail3:
  _HB_OPEN_Free_Coverage( &csf2->Coverage );
  return error;
}


static void  Free_ContextSubst2( HB_ContextSubstFormat2*  csf2 )
{
  HB_UShort         n, count;

  HB_SubClassSet*  scs;


  if ( csf2->SubClassSet )
  {
    count = csf2->SubClassSetCount;
    scs   = csf2->SubClassSet;

    for ( n = 0; n < count; n++ )
      Free_SubClassSet( &scs[n] );

    FREE( scs );
  }

  _HB_OPEN_Free_ClassDefinition( &csf2->ClassDef );
  _HB_OPEN_Free_Coverage( &csf2->Coverage );
}


/* ContextSubstFormat3 */

static HB_Error  Load_ContextSubst3( HB_ContextSubstFormat3*  csf3,
				     HB_Stream                 stream )
{
  HB_Error error;

  HB_UShort               n = 0, m, count;
  HB_UInt                cur_offset, new_offset, base_offset;

  HB_Coverage*           c;
  HB_SubstLookupRecord*  slr;


  base_offset = FILE_Pos() - 2L;

  if ( ACCESS_Frame( 4L ) )
    return error;

  csf3->GlyphCount = GET_UShort();
  csf3->SubstCount = GET_UShort();

  FORGET_Frame();

  csf3->Coverage = NULL;

  count = csf3->GlyphCount;

  if ( ALLOC_ARRAY( csf3->Coverage, count, HB_Coverage ) )
    return error;

  c = csf3->Coverage;

  for ( n = 0; n < count; n++ )
  {
    if ( ACCESS_Frame( 2L ) )
      goto Fail2;

    new_offset = GET_UShort() + base_offset;

    FORGET_Frame();

    cur_offset = FILE_Pos();
    if ( FILE_Seek( new_offset ) ||
	 ( error = _HB_OPEN_Load_Coverage( &c[n], stream ) ) != HB_Err_Ok )
      goto Fail2;
    (void)FILE_Seek( cur_offset );
  }

  csf3->SubstLookupRecord = NULL;

  count = csf3->SubstCount;

  if ( ALLOC_ARRAY( csf3->SubstLookupRecord, count,
		    HB_SubstLookupRecord ) )
    goto Fail2;

  slr = csf3->SubstLookupRecord;

  if ( ACCESS_Frame( count * 4L ) )
    goto Fail1;

  for ( n = 0; n < count; n++ )
  {
    slr[n].SequenceIndex   = GET_UShort();
    slr[n].LookupListIndex = GET_UShort();
  }

  FORGET_Frame();

  return HB_Err_Ok;

Fail1:
  FREE( slr );

Fail2:
  for ( m = 0; m < n; m++ )
    _HB_OPEN_Free_Coverage( &c[m] );

  FREE( c );
  return error;
}


static void  Free_ContextSubst3( HB_ContextSubstFormat3*  csf3 )
{
  HB_UShort      n, count;

  HB_Coverage*  c;


  FREE( csf3->SubstLookupRecord );

  if ( csf3->Coverage )
  {
    count = csf3->GlyphCount;
    c     = csf3->Coverage;

    for ( n = 0; n < count; n++ )
      _HB_OPEN_Free_Coverage( &c[n] );

    FREE( c );
  }
}


/* ContextSubst */

static HB_Error  Load_ContextSubst( HB_GSUB_SubTable* st,
				    HB_Stream         stream )
{
  HB_Error error;
  HB_ContextSubst*  cs = &st->context;


  if ( ACCESS_Frame( 2L ) )
    return error;

  cs->SubstFormat = GET_UShort();

  FORGET_Frame();

  switch ( cs->SubstFormat )
  {
  case 1:  return Load_ContextSubst1( &cs->csf.csf1, stream );
  case 2:  return Load_ContextSubst2( &cs->csf.csf2, stream );
  case 3:  return Load_ContextSubst3( &cs->csf.csf3, stream );
  default: return ERR(HB_Err_Invalid_SubTable_Format);
  }

  return HB_Err_Ok;               /* never reached */
}


static void  Free_ContextSubst( HB_GSUB_SubTable* st )
{
  HB_ContextSubst*  cs = &st->context;

  switch ( cs->SubstFormat )
  {
  case 1:  Free_ContextSubst1( &cs->csf.csf1 ); break;
  case 2:  Free_ContextSubst2( &cs->csf.csf2 ); break;
  case 3:  Free_ContextSubst3( &cs->csf.csf3 ); break;
  default:						break;
  }
}


static HB_Error  Lookup_ContextSubst1( HB_GSUBHeader*          gsub,
				       HB_ContextSubstFormat1* csf1,
				       HB_Buffer               buffer,
				       HB_UShort                flags,
				       HB_UShort                context_length,
				       int                      nesting_level )
{
  HB_UShort        index, property;
  HB_UShort        i, j, k, numsr;
  HB_Error         error;

  HB_SubRule*     sr;
  HB_GDEFHeader*  gdef;


  gdef = gsub->gdef;

  if ( CHECK_Property( gdef, IN_CURITEM(), flags, &property ) )
    return error;

  error = _HB_OPEN_Coverage_Index( &csf1->Coverage, IN_CURGLYPH(), &index );
  if ( error )
    return error;

  sr    = csf1->SubRuleSet[index].SubRule;
  numsr = csf1->SubRuleSet[index].SubRuleCount;

  for ( k = 0; k < numsr; k++ )
  {
    if ( context_length != 0xFFFF && context_length < sr[k].GlyphCount )
      goto next_subrule;

    if ( buffer->in_pos + sr[k].GlyphCount > buffer->in_length )
      goto next_subrule;                        /* context is too long */

    for ( i = 1, j = buffer->in_pos + 1; i < sr[k].GlyphCount; i++, j++ )
    {
      while ( CHECK_Property( gdef, IN_ITEM( j ), flags, &property ) )
      {
	if ( error && error != HB_Err_Not_Covered )
	  return error;

	if ( j + sr[k].GlyphCount - i == (HB_Int)buffer->in_length )
	  goto next_subrule;
	j++;
      }

      if ( IN_GLYPH( j ) != sr[k].Input[i - 1] )
	goto next_subrule;
    }

    return Do_ContextSubst( gsub, sr[k].GlyphCount,
			    sr[k].SubstCount, sr[k].SubstLookupRecord,
			    buffer,
			    nesting_level );
  next_subrule:
    ;
  }

  return HB_Err_Not_Covered;
}


static HB_Error  Lookup_ContextSubst2( HB_GSUBHeader*          gsub,
				       HB_ContextSubstFormat2* csf2,
				       HB_Buffer               buffer,
				       HB_UShort                flags,
				       HB_UShort                context_length,
				       int                      nesting_level )
{
  HB_UShort          index, property;
  HB_Error           error;
  HB_UShort          i, j, k, known_classes;

  HB_UShort*         classes;
  HB_UShort*         cl;

  HB_SubClassSet*   scs;
  HB_SubClassRule*  sr;
  HB_GDEFHeader*    gdef;


  gdef = gsub->gdef;