winfnt.c

下载来的一个看图软件的源代码

    FT_UInt    gindex = 0;
    FT_UInt32  result = 0;
    FT_UInt32  char_code = *pchar_code + 1;


    if ( char_code <= cmap->first )
    {
      result = cmap->first;
      gindex = 1;
    }
    else
    {
      char_code -= cmap->first;
      if ( char_code < cmap->count )
      {
        result = cmap->first + char_code;
        gindex = char_code + 1;
      }
    }

    *pchar_code = result;
    return gindex;
  }


  static FT_CMap_ClassRec  fnt_cmap_class_rec =
  {
    sizeof ( FNT_CMapRec ),

    (FT_CMap_InitFunc)     fnt_cmap_init,
    (FT_CMap_DoneFunc)     NULL,
    (FT_CMap_CharIndexFunc)fnt_cmap_char_index,
    (FT_CMap_CharNextFunc) fnt_cmap_char_next
  };

  static FT_CMap_Class  fnt_cmap_class = &fnt_cmap_class_rec;


  static void
  FNT_Face_Done( FNT_Face  face )
  {
    FT_Memory  memory = FT_FACE_MEMORY( face );


    fnt_font_done( face );

    FT_FREE( face->root.available_sizes );
    face->root.num_fixed_sizes = 0;
  }


  static FT_Error
  FNT_Face_Init( FT_Stream      stream,
                 FNT_Face       face,
                 FT_Int         face_index,
                 FT_Int         num_params,
                 FT_Parameter*  params )
  {
    FT_Error   error;
    FT_Memory  memory = FT_FACE_MEMORY( face );

    FT_UNUSED( num_params );
    FT_UNUSED( params );


    /* try to load font from a DLL */
    error = fnt_face_get_dll_font( face, face_index );
    if ( error )
    {
      /* this didn't work; try to load a single FNT font */
      FNT_Font  font;


      if ( FT_NEW( face->font ) )
        goto Exit;

      face->root.num_faces = 1;

      font           = face->font;
      font->offset   = 0;
      font->fnt_size = stream->size;

      error = fnt_font_load( font, stream );
      if ( error )
        goto Fail;
    }

    /* we now need to fill the root FT_Face fields */
    /* with relevant information                   */
    {
      FT_Face   root = FT_FACE( face );
      FNT_Font  font = face->font;


      root->face_flags = FT_FACE_FLAG_FIXED_SIZES |
                         FT_FACE_FLAG_HORIZONTAL;

      if ( font->header.avg_width == font->header.max_width )
        root->face_flags |= FT_FACE_FLAG_FIXED_WIDTH;

      if ( font->header.italic )
        root->style_flags |= FT_STYLE_FLAG_ITALIC;

      if ( font->header.weight >= 800 )
        root->style_flags |= FT_STYLE_FLAG_BOLD;

      /* set up the `fixed_sizes' array */
      if ( FT_NEW_ARRAY( root->available_sizes, 1 ) )
        goto Fail;

      root->num_fixed_sizes = 1;

      {
        FT_Bitmap_Size*  bsize = root->available_sizes;


        bsize->width  = font->header.avg_width;
        bsize->height =
          font->header.pixel_height + font->header.external_leading;
        bsize->size   = font->header.nominal_point_size << 6;
        bsize->x_ppem = 
          (FT_Pos)( ( font->header.horizontal_resolution * bsize->size + 36 )
                    / 72 );
        bsize->y_ppem =
          (FT_Pos)( ( font->header.vertical_resolution* bsize->size + 36 )
                    / 72 );
      }

      {
        FT_CharMapRec  charmap;


        charmap.encoding    = FT_ENCODING_UNICODE;
        charmap.platform_id = 3;
        charmap.encoding_id = 1;
        charmap.face        = root;

        error = FT_CMap_New( fnt_cmap_class,
                             NULL,
                             &charmap,
                             NULL );
        if ( error )
          goto Fail;

        /* Select default charmap */
        if ( root->num_charmaps )
          root->charmap = root->charmaps[0];
      }

      /* setup remaining flags */

      /* reserve one slot for the .notdef glyph at index 0 */
      root->num_glyphs = font->header.last_char -
                           font->header.first_char + 1 + 1;

      root->family_name = (FT_String*)font->fnt_frame +
                            font->header.face_name_offset;
      root->style_name  = (char *)"Regular";

      if ( root->style_flags & FT_STYLE_FLAG_BOLD )
      {
        if ( root->style_flags & FT_STYLE_FLAG_ITALIC )
          root->style_name = (char *)"Bold Italic";
        else
          root->style_name = (char *)"Bold";
      }
      else if ( root->style_flags & FT_STYLE_FLAG_ITALIC )
        root->style_name = (char *)"Italic";
    }

  Fail:
    if ( error )
      FNT_Face_Done( face );

  Exit:
    return error;
  }


  static FT_Error
  FNT_Size_Set_Pixels( FT_Size  size )
  {
    FNT_Face  face = (FNT_Face)FT_SIZE_FACE( size );
    FT_Face   root = FT_FACE( face );


    if ( size->metrics.y_ppem == root->available_sizes->height )
    {
      FNT_Font  font = face->font;


      size->metrics.ascender    = font->header.ascent * 64;
      size->metrics.descender   = ( font->header.pixel_height -
                                      font->header.ascent ) * 64;
      size->metrics.height      = font->header.pixel_height * 64;
      size->metrics.max_advance = font->header.max_width * 64;

      return FNT_Err_Ok;
    }
    else
      return FNT_Err_Invalid_Pixel_Size;
  }


  static FT_Error
  FNT_Load_Glyph( FT_GlyphSlot  slot,
                  FT_Size       size,
                  FT_UInt       glyph_index,
                  FT_Int32      load_flags )
  {
    FNT_Face    face   = (FNT_Face)FT_SIZE_FACE( size );
    FNT_Font    font   = face->font;
    FT_Error    error  = FNT_Err_Ok;
    FT_Byte*    p;
    FT_Int      len;
    FT_Bitmap*  bitmap = &slot->bitmap;
    FT_ULong    offset;
    FT_Bool     new_format;

    FT_UNUSED( load_flags );


    if ( !face || !font )
    {
      error = FNT_Err_Invalid_Argument;
      goto Exit;
    }

    if ( glyph_index > 0 )
      glyph_index--;                           /* revert to real index */
    else
      glyph_index = font->header.default_char; /* the .notdef glyph */

    new_format = FT_BOOL( font->header.version == 0x300 );
    len        = new_format ? 6 : 4;

    /* jump to glyph entry */
    p = font->fnt_frame + ( new_format ? 146 : 118 ) + len * glyph_index;

    bitmap->width = FT_NEXT_SHORT_LE( p );

    if ( new_format )
      offset = FT_NEXT_ULONG_LE( p );
    else
      offset = FT_NEXT_USHORT_LE( p );

    /* jump to glyph data */
    p = font->fnt_frame + /* font->header.bits_offset */ + offset;

    /* allocate and build bitmap */
    {
      FT_Memory  memory = FT_FACE_MEMORY( slot->face );
      FT_Int     pitch  = ( bitmap->width + 7 ) >> 3;
      FT_Byte*   column;
      FT_Byte*   write;


      bitmap->pitch      = pitch;
      bitmap->rows       = font->header.pixel_height;
      bitmap->pixel_mode = FT_PIXEL_MODE_MONO;

      /* note: since glyphs are stored in columns and not in rows we */
      /*       can't use ft_glyphslot_set_bitmap                     */
      if ( FT_ALLOC( bitmap->buffer, pitch * bitmap->rows ) )
        goto Exit;

      column = (FT_Byte*)bitmap->buffer;

      for ( ; pitch > 0; pitch--, column++ )
      {
        FT_Byte*  limit = p + bitmap->rows;


        for ( write = column; p < limit; p++, write += bitmap->pitch )
          *write = *p;
      }
    }

    slot->internal->flags = FT_GLYPH_OWN_BITMAP;
    slot->bitmap_left     = 0;
    slot->bitmap_top      = font->header.ascent;
    slot->format          = FT_GLYPH_FORMAT_BITMAP;

    /* now set up metrics */
    slot->metrics.horiAdvance  = bitmap->width << 6;
    slot->metrics.horiBearingX = 0;
    slot->metrics.horiBearingY = slot->bitmap_top << 6;

    slot->linearHoriAdvance    = (FT_Fixed)bitmap->width << 16;
    slot->format               = FT_GLYPH_FORMAT_BITMAP;

  Exit:
    return error;
  }


  FT_CALLBACK_TABLE_DEF
  const FT_Driver_ClassRec  winfnt_driver_class =
  {
    {
      FT_MODULE_FONT_DRIVER        |
      FT_MODULE_DRIVER_NO_OUTLINES,
      sizeof ( FT_DriverRec ),

      "winfonts",
      0x10000L,
      0x20000L,

      0,

      (FT_Module_Constructor)0,
      (FT_Module_Destructor) 0,
      (FT_Module_Requester)  0
    },

    sizeof( FNT_FaceRec ),
    sizeof( FT_SizeRec ),
    sizeof( FT_GlyphSlotRec ),

    (FT_Face_InitFunc)        FNT_Face_Init,
    (FT_Face_DoneFunc)        FNT_Face_Done,
    (FT_Size_InitFunc)        0,
    (FT_Size_DoneFunc)        0,
    (FT_Slot_InitFunc)        0,
    (FT_Slot_DoneFunc)        0,

    (FT_Size_ResetPointsFunc) FNT_Size_Set_Pixels,
    (FT_Size_ResetPixelsFunc) FNT_Size_Set_Pixels,
    (FT_Slot_LoadFunc)        FNT_Load_Glyph,

    (FT_Face_GetKerningFunc)  0,
    (FT_Face_AttachFunc)      0,
    (FT_Face_GetAdvancesFunc) 0
  };


/* END */