harfbuzz-gdef.c

Pango is a library for layout and rendering of text, with an emphasis on internationalization. Pang

/*
 * Copyright (C) 1998-2004  David Turner and Werner Lemberg
 * Copyright (C) 2006  Behdad Esfahbod
 *
 *  This is part of HarfBuzz, an OpenType Layout engine library.
 *
 * Permission is hereby granted, without written agreement and without
 * license or royalty fees, to use, copy, modify, and distribute this
 * software and its documentation for any purpose, provided that the
 * above copyright notice and the following two paragraphs appear in
 * all copies of this software.
 *
 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 */

#include "harfbuzz-impl.h"
#include "harfbuzz-gdef-private.h"
#include "harfbuzz-open-private.h"

static HB_Error  Load_AttachList( HB_AttachList*  al,
				  HB_Stream        stream );
static HB_Error  Load_LigCaretList( HB_LigCaretList*  lcl,
				    HB_Stream          stream );

static void  Free_AttachList( HB_AttachList*  al );
static void  Free_LigCaretList( HB_LigCaretList*  lcl );

static void  Free_NewGlyphClasses( HB_GDEFHeader*  gdef );



/* GDEF glyph classes */

#define UNCLASSIFIED_GLYPH  0
#define SIMPLE_GLYPH        1
#define LIGATURE_GLYPH      2
#define MARK_GLYPH          3
#define COMPONENT_GLYPH     4






HB_Error  HB_New_GDEF_Table( HB_GDEFHeader** retptr )
{
  HB_Error         error;

  HB_GDEFHeader*  gdef;

  if ( !retptr )
    return ERR(HB_Err_Invalid_Argument);

  if ( ALLOC( gdef, sizeof( *gdef ) ) )
    return error;

  gdef->GlyphClassDef.loaded = FALSE;
  gdef->AttachList.loaded = FALSE;
  gdef->LigCaretList.loaded = FALSE;
  gdef->MarkAttachClassDef_offset = 0;
  gdef->MarkAttachClassDef.loaded = FALSE;

  gdef->LastGlyph = 0;
  gdef->NewGlyphClasses = NULL;

  *retptr = gdef;

  return HB_Err_Ok;
}


HB_Error  HB_Load_GDEF_Table( HB_Font          font,
			      HB_GDEFHeader** retptr )
{
  HB_Error         error;
  HB_Stream        stream = font->stream;
  HB_UInt         cur_offset, new_offset, base_offset;

  HB_GDEFHeader*  gdef;


  if ( !retptr )
    return ERR(HB_Err_Invalid_Argument);

  if ( GOTO_Table( TTAG_GDEF ) )
    return error;

  if (( error = HB_New_GDEF_Table ( &gdef ) ))
    return error;

  base_offset = FILE_Pos();

  /* skip version */

  if ( FILE_Seek( base_offset + 4L ) ||
       ACCESS_Frame( 2L ) )
    goto Fail0;

  new_offset = GET_UShort();

  FORGET_Frame();

  /* all GDEF subtables are optional */

  if ( new_offset )
  {
    new_offset += base_offset;

    /* only classes 1-4 are allowed here */

    cur_offset = FILE_Pos();
    if ( FILE_Seek( new_offset ) ||
	 ( error = _HB_OPEN_Load_ClassDefinition( &gdef->GlyphClassDef, 5,
					 stream ) ) != HB_Err_Ok )
      goto Fail0;
    (void)FILE_Seek( cur_offset );
  }

  if ( ACCESS_Frame( 2L ) )
    goto Fail1;

  new_offset = GET_UShort();

  FORGET_Frame();

  if ( new_offset )
  {
    new_offset += base_offset;

    cur_offset = FILE_Pos();
    if ( FILE_Seek( new_offset ) ||
	 ( error = Load_AttachList( &gdef->AttachList,
				    stream ) ) != HB_Err_Ok )
      goto Fail1;
    (void)FILE_Seek( cur_offset );
  }

  if ( ACCESS_Frame( 2L ) )
    goto Fail2;

  new_offset = GET_UShort();

  FORGET_Frame();

  if ( new_offset )
  {
    new_offset += base_offset;

    cur_offset = FILE_Pos();
    if ( FILE_Seek( new_offset ) ||
	 ( error = Load_LigCaretList( &gdef->LigCaretList,
				      stream ) ) != HB_Err_Ok )
      goto Fail2;
    (void)FILE_Seek( cur_offset );
  }

  /* OpenType 1.2 has introduced the `MarkAttachClassDef' field.  We
     first have to scan the LookupFlag values to find out whether we
     must load it or not.  Here we only store the offset of the table. */

  if ( ACCESS_Frame( 2L ) )
    goto Fail3;

  new_offset = GET_UShort();

  FORGET_Frame();

  if ( new_offset )
    gdef->MarkAttachClassDef_offset = new_offset + base_offset;
  else
    gdef->MarkAttachClassDef_offset = 0;

  *retptr = gdef;

  return HB_Err_Ok;

Fail3:
  Free_LigCaretList( &gdef->LigCaretList );
  
Fail2:
  Free_AttachList( &gdef->AttachList );

Fail1:
  _HB_OPEN_Free_ClassDefinition( &gdef->GlyphClassDef );

Fail0:
  FREE( gdef );

  return error;
}


HB_Error  HB_Done_GDEF_Table ( HB_GDEFHeader* gdef ) 
{
  Free_LigCaretList( &gdef->LigCaretList );
  Free_AttachList( &gdef->AttachList );
  _HB_OPEN_Free_ClassDefinition( &gdef->GlyphClassDef );
  _HB_OPEN_Free_ClassDefinition( &gdef->MarkAttachClassDef );
  
  Free_NewGlyphClasses( gdef );

  FREE( gdef );

  return HB_Err_Ok;
}




/*******************************
 * AttachList related functions
 *******************************/


/* AttachPoint */

static HB_Error  Load_AttachPoint( HB_AttachPoint*  ap,
				   HB_Stream         stream )
{
  HB_Error  error;

  HB_UShort   n, count;
  HB_UShort*  pi;


  if ( ACCESS_Frame( 2L ) )
    return error;

  count = ap->PointCount = GET_UShort();

  FORGET_Frame();

  ap->PointIndex = NULL;

  if ( count )
  {
    if ( ALLOC_ARRAY( ap->PointIndex, count, HB_UShort ) )
      return error;

    pi = ap->PointIndex;

    if ( ACCESS_Frame( count * 2L ) )
    {
      FREE( pi );
      return error;
    }

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

    FORGET_Frame();
  }

  return HB_Err_Ok;
}


static void  Free_AttachPoint( HB_AttachPoint*  ap )
{
  FREE( ap->PointIndex );
}


/* AttachList */

static HB_Error  Load_AttachList( HB_AttachList*  al,
				  HB_Stream        stream )
{
  HB_Error  error;

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

  HB_AttachPoint*  ap;


  base_offset = FILE_Pos();

  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( &al->Coverage, stream ) ) != HB_Err_Ok )
    return error;
  (void)FILE_Seek( cur_offset );

  if ( ACCESS_Frame( 2L ) )
    goto Fail2;

  count = al->GlyphCount = GET_UShort();

  FORGET_Frame();

  al->AttachPoint = NULL;

  if ( ALLOC_ARRAY( al->AttachPoint, count, HB_AttachPoint ) )
    goto Fail2;

  ap = al->AttachPoint;

  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_AttachPoint( &ap[n], stream ) ) != HB_Err_Ok )
      goto Fail1;
    (void)FILE_Seek( cur_offset );
  }

  al->loaded = TRUE;

  return HB_Err_Ok;

Fail1:
  for ( m = 0; m < n; m++ )
    Free_AttachPoint( &ap[m] );

  FREE( ap );

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


static void  Free_AttachList( HB_AttachList*  al )
{
  HB_UShort         n, count;

  HB_AttachPoint*  ap;


  if ( !al->loaded )
    return;

  if ( al->AttachPoint )
  {
    count = al->GlyphCount;
    ap    = al->AttachPoint;

    for ( n = 0; n < count; n++ )
      Free_AttachPoint( &ap[n] );

    FREE( ap );
  }

  _HB_OPEN_Free_Coverage( &al->Coverage );
}



/*********************************
 * LigCaretList related functions
 *********************************/


/* CaretValueFormat1 */
/* CaretValueFormat2 */
/* CaretValueFormat3 */
/* CaretValueFormat4 */

static HB_Error  Load_CaretValue( HB_CaretValue*  cv,
				  HB_Stream        stream )
{
  HB_Error  error;

  HB_UInt cur_offset, new_offset, base_offset;


  base_offset = FILE_Pos();

  if ( ACCESS_Frame( 2L ) )
    return error;

  cv->CaretValueFormat = GET_UShort();

  FORGET_Frame();

  switch ( cv->CaretValueFormat )
  {
  case 1:
    if ( ACCESS_Frame( 2L ) )
      return error;

    cv->cvf.cvf1.Coordinate = GET_Short();

    FORGET_Frame();

    break;

  case 2:
    if ( ACCESS_Frame( 2L ) )
      return error;

    cv->cvf.cvf2.CaretValuePoint = GET_UShort();

    FORGET_Frame();

    break;

  case 3:
    if ( ACCESS_Frame( 4L ) )
      return error;

    cv->cvf.cvf3.Coordinate = GET_Short();

    new_offset = GET_UShort() + base_offset;

    FORGET_Frame();

    cur_offset = FILE_Pos();
    if ( FILE_Seek( new_offset ) ||
	 ( error = _HB_OPEN_Load_Device( &cv->cvf.cvf3.Device,
				stream ) ) != HB_Err_Ok )
      return error;
    (void)FILE_Seek( cur_offset );

    break;

  case 4:
    if ( ACCESS_Frame( 2L ) )
      return error;

    cv->cvf.cvf4.IdCaretValue = GET_UShort();

    FORGET_Frame();
    break;

  default:
    return ERR(HB_Err_Invalid_SubTable_Format);
  }

  return HB_Err_Ok;
}


static void  Free_CaretValue( HB_CaretValue*  cv )
{
  if ( cv->CaretValueFormat == 3 )
    _HB_OPEN_Free_Device( &cv->cvf.cvf3.Device );
}


/* LigGlyph */

static HB_Error  Load_LigGlyph( HB_LigGlyph*  lg,
				HB_Stream      stream )
{
  HB_Error  error;

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

  HB_CaretValue*  cv;


  base_offset = FILE_Pos();

  if ( ACCESS_Frame( 2L ) )
    return error;

  count = lg->CaretCount = GET_UShort();

  FORGET_Frame();

  lg->CaretValue = NULL;

  if ( ALLOC_ARRAY( lg->CaretValue, count, HB_CaretValue ) )
    return error;

  cv = lg->CaretValue;

  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_CaretValue( &cv[n], stream ) ) != HB_Err_Ok )
      goto Fail;
    (void)FILE_Seek( cur_offset );
  }

  return HB_Err_Ok;

Fail:
  for ( m = 0; m < n; m++ )
    Free_CaretValue( &cv[m] );

  FREE( cv );
  return error;
}


static void  Free_LigGlyph( HB_LigGlyph*  lg )
{
  HB_UShort        n, count;

  HB_CaretValue*  cv;


  if ( lg->CaretValue )
  {
    count = lg->CaretCount;
    cv    = lg->CaretValue;

    for ( n = 0; n < count; n++ )
      Free_CaretValue( &cv[n] );

    FREE( cv );
  }
}


/* LigCaretList */

static HB_Error  Load_LigCaretList( HB_LigCaretList*  lcl,
				    HB_Stream          stream )
{
  HB_Error  error;

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

  HB_LigGlyph*  lg;


  base_offset = FILE_Pos();

  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( &lcl->Coverage, stream ) ) != HB_Err_Ok )
    return error;
  (void)FILE_Seek( cur_offset );

  if ( ACCESS_Frame( 2L ) )
    goto Fail2;

  count = lcl->LigGlyphCount = GET_UShort();

  FORGET_Frame();

  lcl->LigGlyph = NULL;

  if ( ALLOC_ARRAY( lcl->LigGlyph, count, HB_LigGlyph ) )
    goto Fail2;

  lg = lcl->LigGlyph;

  for ( n = 0; n < count; n++ )
  {