pfrload.c

下载来的一个看图软件的源代码

#if 0

  /* load kerning pair data */
  FT_CALLBACK_DEF( FT_Error )
  pfr_extra_item_load_kerning_pairs( FT_Byte*     p,
                                     FT_Byte*     limit,
                                     PFR_PhyFont  phy_font )
  {
    FT_Int        count;
    FT_UShort     base_adj;
    FT_UInt       flags;
    FT_UInt       num_pairs;
    PFR_KernPair  pairs;
    FT_Error      error  = 0;
    FT_Memory     memory = phy_font->memory;


    /* allocate a new kerning item */
    /* XXX: there may be multiple extra items for kerning */
    if ( phy_font->kern_pairs != NULL )
      goto Exit;

    FT_TRACE2(( "pfr_extra_item_load_kerning_pairs()\n" ));

    PFR_CHECK( 4 );

    num_pairs = PFR_NEXT_BYTE( p );
    base_adj  = PFR_NEXT_SHORT( p );
    flags     = PFR_NEXT_BYTE( p );

#ifndef PFR_CONFIG_NO_CHECKS
    count = 3;

    if ( flags & PFR_KERN_2BYTE_CHAR )
      count += 2;

    if ( flags & PFR_KERN_2BYTE_ADJ )
      count += 1;

    PFR_CHECK( num_pairs * count );
#endif

    if ( FT_NEW_ARRAY( pairs, num_pairs ) )
      goto Exit;

    phy_font->num_kern_pairs = num_pairs;
    phy_font->kern_pairs     = pairs;

    for (count = num_pairs ; count > 0; count--, pairs++ )
    {
      if ( flags & PFR_KERN_2BYTE_CHAR )
      {
        pairs->glyph1 = PFR_NEXT_USHORT( p );
        pairs->glyph2 = PFR_NEXT_USHORT( p );
      }
      else
      {
        pairs->glyph1 = PFR_NEXT_BYTE( p );
        pairs->glyph2 = PFR_NEXT_BYTE( p );
      }

      if ( flags & PFR_KERN_2BYTE_ADJ )
        pairs->kerning.x = base_adj + PFR_NEXT_SHORT( p );
      else
        pairs->kerning.x = base_adj + PFR_NEXT_INT8( p );

      pairs->kerning.y = 0;

      FT_TRACE2(( "kerning %d <-> %d : %ld\n",
                   pairs->glyph1, pairs->glyph2, pairs->kerning.x ));
    }

  Exit:
    return error;

  Too_Short:
    error = PFR_Err_Invalid_Table;
    FT_ERROR(( "pfr_extra_item_load_kerning_pairs: "
               "invalid kerning pairs table\n" ));
    goto Exit;
  }

#else /* 0 */

  /* load kerning pair data */
  FT_CALLBACK_DEF( FT_Error )
  pfr_extra_item_load_kerning_pairs( FT_Byte*     p,
                                     FT_Byte*     limit,
                                     PFR_PhyFont  phy_font )
  {
    PFR_KernItem  item;
    FT_Error      error  = 0;
    FT_Memory     memory = phy_font->memory;


    FT_TRACE2(( "pfr_extra_item_load_kerning_pairs()\n" ));

    if ( FT_NEW( item ) )
      goto Exit;

    PFR_CHECK( 4 );

    item->pair_count = PFR_NEXT_BYTE( p );
    item->base_adj   = PFR_NEXT_SHORT( p );
    item->flags      = PFR_NEXT_BYTE( p );
    item->offset     = phy_font->offset + ( p - phy_font->cursor );

#ifndef PFR_CONFIG_NO_CHECKS
    item->pair_size = 3;

    if ( item->flags & PFR_KERN_2BYTE_CHAR )
      item->pair_size += 2;

    if ( item->flags & PFR_KERN_2BYTE_ADJ )
      item->pair_size += 1;

    PFR_CHECK( item->pair_count * item->pair_size );
#endif

    /* load first and last pairs into the item to speed up */
    /* lookup later...                                     */
    if ( item->pair_count > 0 )
    {
      FT_UInt   char1, char2;
      FT_Byte*  q;


      if ( item->flags & PFR_KERN_2BYTE_CHAR )
      {
        q     = p;
        char1 = PFR_NEXT_USHORT( q );
        char2 = PFR_NEXT_USHORT( q );

        item->pair1 = PFR_KERN_INDEX( char1, char2 );

        q = p + item->pair_size * ( item->pair_count - 1 );
        char1 = PFR_NEXT_USHORT( q );
        char2 = PFR_NEXT_USHORT( q );

        item->pair2 = PFR_KERN_INDEX( char1, char2 );
      }
      else
      {
        q     = p;
        char1 = PFR_NEXT_BYTE( q );
        char2 = PFR_NEXT_BYTE( q );

        item->pair1 = PFR_KERN_INDEX( char1, char2 );

        q = p + item->pair_size * ( item->pair_count - 1 );
        char1 = PFR_NEXT_BYTE( q );
        char2 = PFR_NEXT_BYTE( q );

        item->pair2 = PFR_KERN_INDEX( char1, char2 );
      }

      /* add new item to the current list */
      item->next                 = NULL;
      *phy_font->kern_items_tail = item;
      phy_font->kern_items_tail  = &item->next;
      phy_font->num_kern_pairs  += item->pair_count;
    }
    else
    {
      /* empty item! */
      FT_FREE( item );
    }

  Exit:
    return error;

  Too_Short:
    FT_FREE( item );

    error = PFR_Err_Invalid_Table;
    FT_ERROR(( "pfr_extra_item_load_kerning_pairs: "
               "invalid kerning pairs table\n" ));
    goto Exit;
  }
#endif /* 0 */


  static const PFR_ExtraItemRec  pfr_phy_font_extra_items[] =
  {
    { 1, (PFR_ExtraItem_ParseFunc) pfr_extra_item_load_bitmap_info },
    { 2, (PFR_ExtraItem_ParseFunc) pfr_extra_item_load_font_id },
    { 3, (PFR_ExtraItem_ParseFunc) pfr_extra_item_load_stem_snaps },
    { 4, (PFR_ExtraItem_ParseFunc) pfr_extra_item_load_kerning_pairs },
    { 0, NULL }
  };


  /* Loads a name from the auxiliary data.  Since this extracts undocumented
   * strings from the font file, we need to be careful here.
   */
  static FT_Error
  pfr_aux_name_load( FT_Byte*     p,
                     FT_UInt      len,
                     FT_Memory    memory,
                     FT_String*  *astring )
  {
    FT_Error    error = 0;
    FT_String*  result = NULL;
    FT_UInt     n, ok;


    if ( len > 0 && p[len - 1] == 0 )
      len--;

    /* check that each character is ASCII for making sure not to
       load garbage
     */
    ok = ( len > 0 );
    for ( n = 0; n < len; n++ )
      if ( p[n] < 32 || p[n] > 127 )
      {
        ok = 0;
        break;
      }

    if ( ok )
    {
      if ( FT_ALLOC( result, len + 1 ) )
        goto Exit;

      FT_MEM_COPY( result, p, len );
      result[len] = 0;
    }
  Exit:
    *astring = result;
    return error;
  }


  FT_LOCAL_DEF( void )
  pfr_phy_font_done( PFR_PhyFont  phy_font,
                     FT_Memory    memory )
  {
    FT_FREE( phy_font->font_id );
    FT_FREE( phy_font->family_name );
    FT_FREE( phy_font->style_name );

    FT_FREE( phy_font->vertical.stem_snaps );
    phy_font->vertical.num_stem_snaps = 0;

    phy_font->horizontal.stem_snaps     = NULL;
    phy_font->horizontal.num_stem_snaps = 0;

    FT_FREE( phy_font->strikes );
    phy_font->num_strikes = 0;
    phy_font->max_strikes = 0;

    FT_FREE( phy_font->chars );
    phy_font->num_chars    = 0;
    phy_font->chars_offset = 0;

    FT_FREE( phy_font->blue_values );
    phy_font->num_blue_values = 0;

    {
      PFR_KernItem  item, next;


      item = phy_font->kern_items;
      while ( item )
      {
        next = item->next;
        FT_FREE( item );
        item = next;
      }
      phy_font->kern_items      = NULL;
      phy_font->kern_items_tail = NULL;
    }

    phy_font->num_kern_pairs = 0;
  }


  FT_LOCAL_DEF( FT_Error )
  pfr_phy_font_load( PFR_PhyFont  phy_font,
                     FT_Stream    stream,
                     FT_UInt32    offset,
                     FT_UInt32    size )
  {
    FT_Error   error;
    FT_Memory  memory = stream->memory;
    FT_UInt    flags, num_aux;
    FT_Byte*   p;
    FT_Byte*   limit;


    phy_font->memory = memory;
    phy_font->offset = offset;

    phy_font->kern_items      = NULL;
    phy_font->kern_items_tail = &phy_font->kern_items;

    if ( FT_STREAM_SEEK( offset ) || FT_FRAME_ENTER( size ) )
      goto Exit;

    phy_font->cursor = stream->cursor;

    p     = stream->cursor;
    limit = p + size;

    PFR_CHECK( 15 );
    phy_font->font_ref_number    = PFR_NEXT_USHORT( p );
    phy_font->outline_resolution = PFR_NEXT_USHORT( p );
    phy_font->metrics_resolution = PFR_NEXT_USHORT( p );
    phy_font->bbox.xMin          = PFR_NEXT_SHORT( p );
    phy_font->bbox.yMin          = PFR_NEXT_SHORT( p );
    phy_font->bbox.xMax          = PFR_NEXT_SHORT( p );
    phy_font->bbox.yMax          = PFR_NEXT_SHORT( p );
    phy_font->flags      = flags = PFR_NEXT_BYTE( p );

    /* get the standard advance for non-proprotional fonts */
    if ( !(flags & PFR_PHY_PROPORTIONAL) )
    {
      PFR_CHECK( 2 );
      phy_font->standard_advance = PFR_NEXT_SHORT( p );
    }

    /* load the extra items when present */
    if ( flags & PFR_PHY_EXTRA_ITEMS )
    {
      error =  pfr_extra_items_parse( &p, limit,
                                      pfr_phy_font_extra_items, phy_font );

      if ( error )
        goto Fail;
    }

    /* In certain fonts, the auxiliary bytes contain interesting  */
    /* information. These are not in the specification but can be */
    /* guessed by looking at the content of a few PFR0 fonts.     */
    PFR_CHECK( 3 );
    num_aux = PFR_NEXT_ULONG( p );

    if ( num_aux > 0 )
    {
      FT_Byte*  q = p;
      FT_Byte*  q2;


      PFR_CHECK( num_aux );
      p += num_aux;

      while ( num_aux > 0 )
      {
        FT_UInt  length, type;


        if ( q + 4 > p )
          break;

        length = PFR_NEXT_USHORT( q );
        if ( length < 4 || length > num_aux )
          break;

        q2   = q + length - 2;
        type = PFR_NEXT_USHORT( q );

        switch ( type )
        {
        case 1:
          /* this seems to correspond to the font's family name,
           * padded to 16-bits with one zero when necessary
           */
          error = pfr_aux_name_load( q, length - 4U, memory,
                                     &phy_font->family_name );
          if ( error )
            goto Exit;
          break;

        case 2:
          if ( q + 32 > q2 )
            break;

          q += 10;
          phy_font->ascent  = PFR_NEXT_SHORT( q );
          phy_font->descent = PFR_NEXT_SHORT( q );
          phy_font->leading = PFR_NEXT_SHORT( q );
          q += 16;
          break;

        case 3:
          /* this seems to correspond to the font's style name,
           * padded to 16-bits with one zero when necessary
           */
          error = pfr_aux_name_load( q, length - 4U, memory,
                                     &phy_font->style_name );
          if ( error )
            goto Exit;
          break;

        default:
          ;
        }

        q        = q2;
        num_aux -= length;
      }
    }

    /* read the blue values */
    {
      FT_UInt  n, count;


      PFR_CHECK( 1 );
      phy_font->num_blue_values = count = PFR_NEXT_BYTE( p );

      PFR_CHECK( count * 2 );

      if ( FT_NEW_ARRAY( phy_font->blue_values, count ) )
        goto Fail;

      for ( n = 0; n < count; n++ )
        phy_font->blue_values[n] = PFR_NEXT_SHORT( p );
    }

    PFR_CHECK( 8 );
    phy_font->blue_fuzz  = PFR_NEXT_BYTE( p );
    phy_font->blue_scale = PFR_NEXT_BYTE( p );

    phy_font->vertical.standard   = PFR_NEXT_USHORT( p );
    phy_font->horizontal.standard = PFR_NEXT_USHORT( p );

    /* read the character descriptors */
    {
      FT_UInt  n, count, Size;


      phy_font->num_chars    = count = PFR_NEXT_USHORT( p );
      phy_font->chars_offset = offset + ( p - stream->cursor );

      if ( FT_NEW_ARRAY( phy_font->chars, count ) )
        goto Fail;

      Size = 1 + 1 + 2;
      if ( flags & PFR_PHY_2BYTE_CHARCODE )
        Size += 1;

      if ( flags & PFR_PHY_PROPORTIONAL )
        Size += 2;

      if ( flags & PFR_PHY_ASCII_CODE )
        Size += 1;

      if ( flags & PFR_PHY_2BYTE_GPS_SIZE )
        Size += 1;

      if ( flags & PFR_PHY_3BYTE_GPS_OFFSET )
        Size += 1;

      PFR_CHECK( count * Size );

      for ( n = 0; n < count; n++ )
      {
        PFR_Char  cur = &phy_font->chars[n];


        cur->char_code = ( flags & PFR_PHY_2BYTE_CHARCODE )
                         ? PFR_NEXT_USHORT( p )
                         : PFR_NEXT_BYTE( p );

        cur->advance   = ( flags & PFR_PHY_PROPORTIONAL )
                         ? PFR_NEXT_SHORT( p )
                         : (FT_Int) phy_font->standard_advance;

#if 0
        cur->ascii     = ( flags & PFR_PHY_ASCII_CODE )
                         ? PFR_NEXT_BYTE( p )
                         : 0;
#else
        if ( flags & PFR_PHY_ASCII_CODE )
          p += 1;
#endif
        cur->gps_size  = ( flags & PFR_PHY_2BYTE_GPS_SIZE )
                         ? PFR_NEXT_USHORT( p )
                         : PFR_NEXT_BYTE( p );

        cur->gps_offset = ( flags & PFR_PHY_3BYTE_GPS_OFFSET )
                          ? PFR_NEXT_ULONG( p )
                          : PFR_NEXT_USHORT( p );
      }
    }

    /* that's it! */

  Fail:
    FT_FRAME_EXIT();

    /* save position of bitmap info */
    phy_font->bct_offset = FT_STREAM_POS();
    phy_font->cursor     = NULL;

  Exit:
    return error;

  Too_Short:
    error = PFR_Err_Invalid_Table;
    FT_ERROR(( "pfr_phy_font_load: invalid physical font table\n" ));
    goto Fail;
  }


/* END */