ftobjs.c

一个类似windows

  }


  /* documentation is in freetype.h */

  FT_EXPORT_DEF( FT_Error )
  FT_Attach_Stream( FT_Face        face,
                    FT_Open_Args*  parameters )
  {
    FT_Stream  stream;
    FT_Error   error;
    FT_Driver  driver;

    FT_Driver_Class  clazz;


    /* test for valid `parameters' delayed to FT_Stream_New() */

    if ( !face )
      return FT_Err_Invalid_Face_Handle;

    driver = face->driver;
    if ( !driver )
      return FT_Err_Invalid_Driver_Handle;

    error = FT_Stream_New( driver->root.library, parameters, &stream );
    if ( error )
      goto Exit;

    /* we implement FT_Attach_Stream in each driver through the */
    /* `attach_file' interface                                  */

    error = FT_Err_Unimplemented_Feature;
    clazz = driver->clazz;
    if ( clazz->attach_file )
      error = clazz->attach_file( face, stream );

    /* close the attached stream */
    FT_Stream_Free( stream,
                    (FT_Bool)( parameters->stream &&
                               ( parameters->flags & FT_OPEN_STREAM ) ) );

  Exit:
    return error;
  }


  /* documentation is in freetype.h */

  FT_EXPORT_DEF( FT_Error )
  FT_Done_Face( FT_Face  face )
  {
    FT_Error     error;
    FT_Driver    driver;
    FT_Memory    memory;
    FT_ListNode  node;


    error = FT_Err_Invalid_Face_Handle;
    if ( face && face->driver )
    {
      driver = face->driver;
      memory = driver->root.memory;

      /* find face in driver's list */
      node = FT_List_Find( &driver->faces_list, face );
      if ( node )
      {
        /* remove face object from the driver's list */
        FT_List_Remove( &driver->faces_list, node );
        FT_FREE( node );

        /* now destroy the object proper */
        destroy_face( memory, face, driver );
        error = FT_Err_Ok;
      }
    }
    return error;
  }


  /* documentation is in ftobjs.h */

  FT_EXPORT_DEF( FT_Error )
  FT_New_Size( FT_Face   face,
               FT_Size  *asize )
  {
    FT_Error         error;
    FT_Memory        memory;
    FT_Driver        driver;
    FT_Driver_Class  clazz;

    FT_Size          size = 0;
    FT_ListNode      node = 0;


    if ( !face )
      return FT_Err_Invalid_Face_Handle;

    if ( !asize )
      return FT_Err_Invalid_Size_Handle;

    if ( !face->driver )
      return FT_Err_Invalid_Driver_Handle;

    *asize = 0;

    driver = face->driver;
    clazz  = driver->clazz;
    memory = face->memory;

    /* Allocate new size object and perform basic initialisation */
    if ( FT_ALLOC( size, clazz->size_object_size ) || FT_NEW( node ) )
      goto Exit;

    size->face = face;

    /* for now, do not use any internal fields in size objects */
    size->internal = 0;

    if ( clazz->init_size )
      error = clazz->init_size( size );

    /* in case of success, add to the face's list */
    if ( !error )
    {
      *asize     = size;
      node->data = size;
      FT_List_Add( &face->sizes_list, node );
    }

  Exit:
    if ( error )
    {
      FT_FREE( node );
      FT_FREE( size );
    }

    return error;
  }


  /* documentation is in ftobjs.h */

  FT_EXPORT_DEF( FT_Error )
  FT_Done_Size( FT_Size  size )
  {
    FT_Error     error;
    FT_Driver    driver;
    FT_Memory    memory;
    FT_Face      face;
    FT_ListNode  node;


    if ( !size )
      return FT_Err_Invalid_Size_Handle;

    face = size->face;
    if ( !face )
      return FT_Err_Invalid_Face_Handle;

    driver = face->driver;
    if ( !driver )
      return FT_Err_Invalid_Driver_Handle;

    memory = driver->root.memory;

    error = FT_Err_Ok;
    node  = FT_List_Find( &face->sizes_list, size );
    if ( node )
    {
      FT_List_Remove( &face->sizes_list, node );
      FT_FREE( node );

      if ( face->size == size )
      {
        face->size = 0;
        if ( face->sizes_list.head )
          face->size = (FT_Size)(face->sizes_list.head->data);
      }

      destroy_size( memory, size, driver );
    }
    else
      error = FT_Err_Invalid_Size_Handle;

    return error;
  }


  static void
  ft_recompute_scaled_metrics( FT_Face           face,
                               FT_Size_Metrics*  metrics )
  {
    /* Compute root ascender, descender, test height, and max_advance */

    metrics->ascender    = FT_PIX_CEIL( FT_MulFix( face->ascender,
                                                   metrics->y_scale ) );

    metrics->descender   = FT_PIX_FLOOR( FT_MulFix( face->descender,
                                                    metrics->y_scale ) );

    metrics->height      = FT_PIX_ROUND( FT_MulFix( face->height,
                                                    metrics->y_scale ) );

    metrics->max_advance = FT_PIX_ROUND( FT_MulFix( face->max_advance_width,
                                                    metrics->x_scale ) );
  }


  /* documentation is in freetype.h */

  FT_EXPORT_DEF( FT_Error )
  FT_Set_Char_Size( FT_Face     face,
                    FT_F26Dot6  char_width,
                    FT_F26Dot6  char_height,
                    FT_UInt     horz_resolution,
                    FT_UInt     vert_resolution )
  {
    FT_Error          error = FT_Err_Ok;
    FT_Driver         driver;
    FT_Driver_Class   clazz;
    FT_Size_Metrics*  metrics;
    FT_Long           dim_x, dim_y;


    if ( !face || !face->size || !face->driver )
      return FT_Err_Invalid_Face_Handle;

    driver  = face->driver;
    metrics = &face->size->metrics;
    clazz   = driver->clazz;

    if ( !char_width )
      char_width = char_height;

    else if ( !char_height )
      char_height = char_width;

    if ( !horz_resolution )
      horz_resolution = 72;

    if ( !vert_resolution )
      vert_resolution = 72;

    /* default processing -- this can be overridden by the driver */
    if ( char_width  < 1 * 64 )
      char_width  = 1 * 64;
    if ( char_height < 1 * 64 )
      char_height = 1 * 64;

    /* Compute pixel sizes in 26.6 units */
    dim_x = ( char_width  * horz_resolution + 36 ) / 72;
    dim_y = ( char_height * vert_resolution + 36 ) / 72;

    {
      FT_UShort  x_ppem = (FT_UShort)( ( dim_x + 32 ) >> 6 );
      FT_UShort  y_ppem = (FT_UShort)( ( dim_y + 32 ) >> 6 );


      /* Don't take, say, 12.5x12.5 equal to 13x13.  If working with */
      /* fractional font sizes this would hide slightly different    */
      /* font metrics.  Consequently, the next two lines are         */
      /* disabled.                                                   */
#if 0
      if ( x_ppem == metrics->x_ppem && y_ppem == metrics->y_ppem )
        return FT_Err_Ok;
#endif

      metrics->x_ppem = x_ppem;
      metrics->y_ppem = y_ppem;
    }

    metrics->x_scale = 0x10000L;
    metrics->y_scale = 0x10000L;

    if ( face->face_flags & FT_FACE_FLAG_SCALABLE )
    {
      metrics->x_scale = FT_DivFix( dim_x, face->units_per_EM );
      metrics->y_scale = FT_DivFix( dim_y, face->units_per_EM );

      ft_recompute_scaled_metrics( face, metrics );
    }

    if ( clazz->set_char_sizes )
      error = clazz->set_char_sizes( face->size,
                                     char_width,
                                     char_height,
                                     horz_resolution,
                                     vert_resolution );
    return error;
  }


  /* documentation is in freetype.h */

  FT_EXPORT_DEF( FT_Error )
  FT_Set_Pixel_Sizes( FT_Face  face,
                      FT_UInt  pixel_width,
                      FT_UInt  pixel_height )
  {
    FT_Error          error = FT_Err_Ok;
    FT_Driver         driver;
    FT_Driver_Class   clazz;
    FT_Size_Metrics*  metrics;


    if ( !face || !face->size || !face->driver )
      return FT_Err_Invalid_Face_Handle;

    driver  = face->driver;
    metrics = &face->size->metrics;
    clazz   = driver->clazz;

    if ( pixel_width == 0 )
      pixel_width = pixel_height;

    else if ( pixel_height == 0 )
      pixel_height = pixel_width;

    if ( pixel_width  < 1 )
      pixel_width  = 1;
    if ( pixel_height < 1 )
      pixel_height = 1;

    /* use `>=' to avoid potention compiler warning on 16bit platforms */
    if ( pixel_width  >= 0xFFFFU )
      pixel_width  = 0xFFFFU;
    if ( pixel_height >= 0xFFFFU )
      pixel_height = 0xFFFFU;

    metrics->x_ppem = (FT_UShort)pixel_width;
    metrics->y_ppem = (FT_UShort)pixel_height;

    if ( face->face_flags & FT_FACE_FLAG_SCALABLE )
    {
      metrics->x_scale = FT_DivFix( metrics->x_ppem << 6,
                                    face->units_per_EM );

      metrics->y_scale = FT_DivFix( metrics->y_ppem << 6,
                                    face->units_per_EM );

      ft_recompute_scaled_metrics( face, metrics );
    }

    if ( clazz->set_pixel_sizes )
      error = clazz->set_pixel_sizes( face->size,
                                      pixel_width,
                                      pixel_height );
    return error;
  }


  /* documentation is in freetype.h */

  FT_EXPORT_DEF( FT_Error )
  FT_Get_Kerning( FT_Face     face,
                  FT_UInt     left_glyph,
                  FT_UInt     right_glyph,
                  FT_UInt     kern_mode,
                  FT_Vector  *akerning )
  {
    FT_Error   error = FT_Err_Ok;
    FT_Driver  driver;


    if ( !face )
      return FT_Err_Invalid_Face_Handle;

    if ( !akerning )
      return FT_Err_Invalid_Argument;

    driver = face->driver;

    akerning->x = 0;
    akerning->y = 0;

    if ( driver->clazz->get_kerning )
    {
      error = driver->clazz->get_kerning( face,
                                          left_glyph,
                                          right_glyph,
                                          akerning );
      if ( !error )
      {
        if ( kern_mode != FT_KERNING_UNSCALED )
        {
          akerning->x = FT_MulFix( akerning->x, face->size->metrics.x_scale );
          akerning->y = FT_MulFix( akerning->y, face->size->metrics.y_scale );

          if ( kern_mode != FT_KERNING_UNFITTED )
          {
            /* we scale down kerning values for small ppem values */
            /* to avoid that rounding makes them too big.         */
            /* `25' has been determined heuristically.            */
            if ( face->size->metrics.x_ppem < 25 )
              akerning->x = FT_MulDiv( akerning->x,
                                       face->size->metrics.x_ppem, 25 );
            if ( face->size->metrics.y_ppem < 25 )
              akerning->y = FT_MulDiv( akerning->y,
                                       face->size->metrics.y_ppem, 25 );

            akerning->x = FT_PIX_ROUND( akerning->x );
            akerning->y = FT_PIX_ROUND( akerning->y );
          }
        }
      }
    }

    return error;
  }


  /* documentation is in freetype.h */

  FT_EXPORT_DEF( FT_Error )
  FT_Select_Charmap( FT_Face      face,
                     FT_Encoding  encoding )
  {
    FT_CharMap*  cur;
    FT_CharMap*  limit;


    if ( !face )
      return FT_Err_Invalid_Face_Handle;

    /* FT_ENCODING_UNICODE is special.  We try to find the `best' Unicode */
    /* charmap available, i.e., one with UCS-4 characters, if possible.   */
    /*                                                                    */
    /* This is done by find_unicode_charmap() above, to share code.       */
    if ( encoding == FT_ENCODING_UNICODE )
      return find_unicode_charmap( face );

    cur = face->charmaps;
    if ( !cur )
      return FT_Err_Invalid_CharMap_Handle;

    limit =