ftxopen.c

神龙卡开发原代码

/*******************************************************************
 *
 *  ftxopen.c
 *
 *    TrueType Open common table support.
 *
 *  Copyright 1996-1999 by
 *  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.
 *
 ******************************************************************/

#include "tttypes.h"
#include "ttload.h"
#include "ttextend.h"
#include "ttmemory.h"
#include "ttfile.h"

#include "ftxopen.h"
#include "ftxopenf.h"


  /***************************
   * Script related functions
   ***************************/


  /* LangSys */

  static TT_Error  Load_LangSys( TTO_LangSys*  ls,
                                 PFace         input )
  {
    DEFINE_LOAD_LOCALS( input->stream );

    UShort   n, count;

    UShort*  fi;


    if ( ACCESS_Frame( 6L ) )
      return error;

    ls->LookupOrderOffset    = GET_UShort();    /* should be 0 */
    ls->ReqFeatureIndex      = GET_UShort();
    count = ls->FeatureCount = GET_UShort();

    FORGET_Frame();

    ls->FeatureIndex = NULL;

    if ( ALLOC_ARRAY( ls->FeatureIndex, count, UShort ) )
      return error;

    if ( ACCESS_Frame( count * 2L ) )
    {
      FREE( ls->FeatureIndex );
      return error;
    }

    fi = ls->FeatureIndex;

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

    FORGET_Frame();

    return TT_Err_Ok;
  }


  static void  Free_LangSys( TTO_LangSys*  ls )
  {
    FREE( ls->FeatureIndex );
  }


  /* Script */

  static TT_Error  Load_Script( TTO_Script*  s,
                                PFace        input )
  {
    DEFINE_LOAD_LOCALS( input->stream );

    UShort              n, count;
    ULong               cur_offset, new_offset, base_offset;

    TTO_LangSysRecord*  lsr;


    base_offset = FILE_Pos();

    if ( ACCESS_Frame( 2L ) )
      return error;

    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_LangSys( &s->DefaultLangSys,
                                   input ) ) != TT_Err_Ok )
        return error;
      (void)FILE_Seek( cur_offset );
    }
    else
    {
      /* we create a DefaultLangSys table with no entries */

      s->DefaultLangSys.LookupOrderOffset = 0;
      s->DefaultLangSys.ReqFeatureIndex   = 0xFFFF;
      s->DefaultLangSys.FeatureCount      = 0;
      s->DefaultLangSys.FeatureIndex      = NULL;
    }

    if ( ACCESS_Frame( 2L ) )
      goto Fail2;

    count = s->LangSysCount = GET_UShort();

    /* safety check; otherwise the official handling of TrueType Open
       fonts won't work */

    if ( s->LangSysCount == 0 && s->DefaultLangSys.FeatureCount == 0 )
    {
      error = TTO_Err_Invalid_SubTable;
      goto Fail2;
    }

    FORGET_Frame();

    s->LangSysRecord = NULL;

    if ( ALLOC_ARRAY( s->LangSysRecord, count, TTO_LangSysRecord ) )
      goto Fail2;

    lsr = s->LangSysRecord;

    for ( n = 0; n < count; n++ )
    {
      if ( ACCESS_Frame( 6L ) )
        goto Fail1;

      lsr[n].LangSysTag = GET_ULong();
      new_offset = GET_UShort() + base_offset;

      FORGET_Frame();

      cur_offset = FILE_Pos();
      if ( FILE_Seek( new_offset ) ||
           ( error = Load_LangSys( &lsr[n].LangSys, input ) ) != TT_Err_Ok )
        goto Fail1;
      (void)FILE_Seek( cur_offset );
    }

    return TT_Err_Ok;

  Fail1:
    for ( n = 0; n < count; n++ )
      Free_LangSys( &lsr[n].LangSys );

    FREE( s->LangSysRecord );

  Fail2:
    Free_LangSys( &s->DefaultLangSys );
    return error;
  }


  static void  Free_Script( TTO_Script*  s )
  {
    UShort              n, count;

    TTO_LangSysRecord*  lsr;


    Free_LangSys( &s->DefaultLangSys );

    if ( s->LangSysRecord )
    {
      count = s->LangSysCount;
      lsr   = s->LangSysRecord;

      for ( n = 0; n < count; n++ )
        Free_LangSys( &lsr[n].LangSys );

      FREE( lsr );
    }
  }


  /* ScriptList */

  TT_Error  Load_ScriptList( TTO_ScriptList*  sl,
                             PFace            input )
  {
    DEFINE_LOAD_LOCALS( input->stream );

    UShort             n, count;
    ULong              cur_offset, new_offset, base_offset;

    TTO_ScriptRecord*  sr;


    base_offset = FILE_Pos();

    if ( ACCESS_Frame( 2L ) )
      return error;

    count = sl->ScriptCount = GET_UShort();

    FORGET_Frame();

    sl->ScriptRecord = NULL;

    if ( ALLOC_ARRAY( sl->ScriptRecord, count, TTO_ScriptRecord ) )
      return error;

    sr = sl->ScriptRecord;

    for ( n = 0; n < count; n++ )
    {
      if ( ACCESS_Frame( 6L ) )
        goto Fail;

      sr[n].ScriptTag = GET_ULong();
      new_offset = GET_UShort() + base_offset;

      FORGET_Frame();

      cur_offset = FILE_Pos();
      if ( FILE_Seek( new_offset ) ||
           ( error = Load_Script( &sr[n].Script, input ) ) != TT_Err_Ok )
        goto Fail;
      (void)FILE_Seek( cur_offset );
    }

    return TT_Err_Ok;

  Fail:
    for ( n = 0; n < count; n++ )
      Free_Script( &sr[n].Script );

    FREE( sl->ScriptRecord );
    return error;
  }


  void  Free_ScriptList( TTO_ScriptList*  sl )
  {
    UShort             n, count;

    TTO_ScriptRecord*  sr;


    if ( sl->ScriptRecord )
    {
      count = sl->ScriptCount;
      sr    = sl->ScriptRecord;

      for ( n = 0; n < count; n++ )
        Free_Script( &sr[n].Script );

      FREE( sr );
    }
  }



  /*********************************
   * Feature List related functions
   *********************************/


  /* Feature */

  static TT_Error  Load_Feature( TTO_Feature*  f,
                                 PFace         input )
  {
    DEFINE_LOAD_LOCALS( input->stream );

    UShort   n, count;

    UShort*  lli;


    if ( ACCESS_Frame( 4L ) )
      return error;

    f->FeatureParams           = GET_UShort();    /* should be 0 */
    count = f->LookupListCount = GET_UShort();

    FORGET_Frame();

    f->LookupListIndex = NULL;

    if ( ALLOC_ARRAY( f->LookupListIndex, count, UShort ) )
      return error;

    lli = f->LookupListIndex;

    if ( ACCESS_Frame( count * 2L ) )
    {
      FREE( f->LookupListIndex );
      return error;
    }

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

    FORGET_Frame();

    return TT_Err_Ok;
  }


  static void  Free_Feature( TTO_Feature*  f )
  {
    FREE( f->LookupListIndex );
  }


  /* FeatureList */

  TT_Error  Load_FeatureList( TTO_FeatureList*  fl,
                              PFace             input )
  {
    DEFINE_LOAD_LOCALS( input->stream );

    UShort              n, count;
    ULong               cur_offset, new_offset, base_offset;

    TTO_FeatureRecord*  fr;


    base_offset = FILE_Pos();

    if ( ACCESS_Frame( 2L ) )
      return error;

    count = fl->FeatureCount = GET_UShort();

    FORGET_Frame();

    fl->FeatureRecord = NULL;

    if ( ALLOC_ARRAY( fl->FeatureRecord, count, TTO_FeatureRecord ) )
      return error;

    fr = fl->FeatureRecord;

    for ( n = 0; n < count; n++ )
    {
      if ( ACCESS_Frame( 6L ) )
        goto Fail;

      fr[n].FeatureTag = GET_ULong();
      new_offset = GET_UShort() + base_offset;

      FORGET_Frame();

      cur_offset = FILE_Pos();
      if ( FILE_Seek( new_offset ) ||
           ( error = Load_Feature( &fr[n].Feature, input ) ) != TT_Err_Ok )
        goto Fail;
      (void)FILE_Seek( cur_offset );
    }

    return TT_Err_Ok;

  Fail:
    for ( n = 0; n < count; n++ )
      Free_Feature( &fr[n].Feature );

    FREE( fl->FeatureRecord );
    return error;
  }


  void  Free_FeatureList( TTO_FeatureList*  fl )
  {
    UShort              n, count;

    TTO_FeatureRecord*  fr;


    if ( fl->FeatureRecord )
    {
      count = fl->FeatureCount;
      fr    = fl->FeatureRecord;

      for ( n = 0; n < count; n++ )
        Free_Feature( &fr[n].Feature );

      FREE( fr );
    }
  }



  /********************************
   * Lookup List related functions
   ********************************/

  /* the subroutines of the following two functions are defined in
     ftxgsub.c and ftxgpos.c respectively                          */


  /* SubTable */

  static TT_Error  Load_SubTable( TTO_SubTable*  st,
                                  PFace          input,
                                  TTO_Type       table_type,
                                  UShort         lookup_type )
  {
    if ( table_type == GSUB )
      switch ( lookup_type )
      {
      case GSUB_LOOKUP_SINGLE:
        return Load_SingleSubst( &st->st.gsub.single, input );

      case GSUB_LOOKUP_MULTIPLE:
        return Load_MultipleSubst( &st->st.gsub.multiple, input );

      case GSUB_LOOKUP_ALTERNATE:
        return Load_AlternateSubst( &st->st.gsub.alternate, input );

      case GSUB_LOOKUP_LIGATURE:
        return Load_LigatureSubst( &st->st.gsub.ligature, input );

      case GSUB_LOOKUP_CONTEXT:
        return Load_ContextSubst( &st->st.gsub.context, input );

      case GSUB_LOOKUP_CHAIN:
        return Load_ChainContextSubst( &st->st.gsub.chain, input );

      default:
        return TTO_Err_Invalid_GSUB_SubTable_Format;
      }
    else
      switch ( lookup_type )
      {
        case GPOS_LOOKUP_SINGLE:
          return Load_SinglePos( &st->st.gpos.single, input );

        case GPOS_LOOKUP_PAIR:
          return Load_PairPos( &st->st.gpos.pair, input );

        case GPOS_LOOKUP_CURSIVE:
          return Load_CursivePos( &st->st.gpos.cursive, input );

        case GPOS_LOOKUP_MARKBASE:
          return Load_MarkBasePos( &st->st.gpos.markbase, input );

        case GPOS_LOOKUP_MARKLIG:
          return Load_MarkLigPos( &st->st.gpos.marklig, input );

        case GPOS_LOOKUP_MARKMARK:
          return Load_MarkMarkPos( &st->st.gpos.markmark, input );

        case GPOS_LOOKUP_CONTEXT:
          return Load_ContextPos( &st->st.gpos.context, input );

        case GPOS_LOOKUP_CHAIN:
          return Load_ChainContextPos ( &st->st.gpos.chain, input );

        default:
          return TTO_Err_Invalid_GPOS_SubTable_Format;
      }

    return TT_Err_Ok;           /* never reached */
  }


  static void  Free_SubTable( TTO_SubTable*  st,
                              TTO_Type       table_type,
                              UShort         lookup_type )
  {
    if ( table_type == GSUB )
      switch ( lookup_type )
      {
      case GSUB_LOOKUP_SINGLE:
        Free_SingleSubst( &st->st.gsub.single );
        break;

      case GSUB_LOOKUP_MULTIPLE:
        Free_MultipleSubst( &st->st.gsub.multiple );
        break;

      case GSUB_LOOKUP_ALTERNATE:
        Free_AlternateSubst( &st->st.gsub.alternate );
        break;

      case GSUB_LOOKUP_LIGATURE:
        Free_LigatureSubst( &st->st.gsub.ligature );
        break;

      case GSUB_LOOKUP_CONTEXT:
        Free_ContextSubst( &st->st.gsub.context );
        break;

      case GSUB_LOOKUP_CHAIN:
        Free_ChainContextSubst( &st->st.gsub.chain );
        break;
      }
    else
      switch ( lookup_type )
      {
      case GPOS_LOOKUP_SINGLE:
        Free_SinglePos( &st->st.gpos.single );
        break;

      case GPOS_LOOKUP_PAIR:
        Free_PairPos( &st->st.gpos.pair );
        break;

      case GPOS_LOOKUP_CURSIVE:
        Free_CursivePos( &st->st.gpos.cursive );
        break;

      case GPOS_LOOKUP_MARKBASE:
        Free_MarkBasePos( &st->st.gpos.markbase );
        break;

      case GPOS_LOOKUP_MARKLIG:
        Free_MarkLigPos( &st->st.gpos.marklig );
        break;

      case GPOS_LOOKUP_MARKMARK:
        Free_MarkMarkPos( &st->st.gpos.markmark );
        break;

      case GPOS_LOOKUP_CONTEXT:
        Free_ContextPos( &st->st.gpos.context );
        break;

      case GPOS_LOOKUP_CHAIN:
        Free_ChainContextPos ( &st->st.gpos.chain );
        break;
      }
  }


  /* Lookup */

  static TT_Error  Load_Lookup( TTO_Lookup*   l,
                                PFace         input,
                                TTO_Type      type )
  {
    DEFINE_LOAD_LOCALS( input->stream );

    UShort         n, count;
    ULong          cur_offset, new_offset, base_offset;

    TTO_SubTable*  st;


    base_offset = FILE_Pos();

    if ( ACCESS_Frame( 6L ) )
      return error;

    l->LookupType            = GET_UShort();
    l->LookupFlag            = GET_UShort();
    count = l->SubTableCount = GET_UShort();

    FORGET_Frame();

    l->SubTable = NULL;

    if ( ALLOC_ARRAY( l->SubTable, count, TTO_SubTable ) )
      return error;

    st = l->SubTable;

    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_SubTable( &st[n], input,
                                    type, l->LookupType ) ) != TT_Err_Ok )
        goto Fail;
      (void)FILE_Seek( cur_offset );
    }

    return TT_Err_Ok;

  Fail:
    for ( n = 0; n < count; n++ )
      Free_SubTable( &st[n], type, l->LookupType );

    FREE( l->SubTable );
    return error;
  }


  static void  Free_Lookup( TTO_Lookup*   l,
                            TTO_Type      type )
  {
    UShort         n, count;

    TTO_SubTable*  st;


    if ( l->SubTable )
    {
      count = l->SubTableCount;
      st    = l->SubTable;

      for ( n = 0; n < count; n++ )
        Free_SubTable( &st[n], type, l->LookupType );

      FREE( st );
    }
  }


  /* LookupList */

  TT_Error  Load_LookupList( TTO_LookupList*  ll,
                             PFace            input,
                             TTO_Type         type )
  {
    DEFINE_LOAD_LOCALS( input->stream );

    UShort       n, count;
    ULong        cur_offset, new_offset, base_offset;

    TTO_Lookup*  l;


    base_offset = FILE_Pos();

    if ( ACCESS_Frame( 2L ) )
      return error;

    count = ll->LookupCount = GET_UShort();

    FORGET_Frame();

    ll->Lookup = NULL;

    if ( ALLOC_ARRAY( ll->Lookup, count, TTO_Lookup ) )
      return error;
    if ( ALLOC_ARRAY( ll->Properties, count, UShort ) )
      goto Fail2;

    l = ll->Lookup;

    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_Lookup( &l[n], input, type ) ) != TT_Err_Ok )
        goto Fail1;
      (void)FILE_Seek( cur_offset );
    }

    return TT_Err_Ok;

  Fail1:
    FREE( ll->Properties );

    for ( n = 0; n < count; n++ )
      Free_Lookup( &l[n], type );

  Fail2:
    FREE( ll->Lookup );
    return error;
  }


  void  Free_LookupList( TTO_LookupList*  ll,
                         TTO_Type         type )
  {
    UShort       n, count;

    TTO_Lookup*  l;


    FREE( ll->Properties );

    if ( ll->Lookup )
    {
      count = ll->LookupCount;
      l     = ll->Lookup;

      for ( n = 0; n < count; n++ )
        Free_Lookup( &l[n], type );

      FREE( l );
    }
  }



  /*****************************
   * Coverage related functions
   *****************************/