  ft_smooth_render_generic( FT_Renderer       render,
                            FT_GlyphSlot      slot,
                            FT_Render_Mode    mode,
                            const FT_Vector*  origin,
                            FT_Render_Mode    required_mode )
  {
    FT_Error     error;
    FT_Outline*  outline = NULL;
    FT_BBox      cbox;
    FT_UInt      width, height, height_org, width_org, pitch;
    FT_Bitmap*   bitmap;
    FT_Memory    memory;
    FT_Int       hmul = mode == FT_RENDER_MODE_LCD;
    FT_Int       vmul = mode == FT_RENDER_MODE_LCD_V;
    FT_Pos       x_shift, y_shift, x_left, y_top;

    FT_Raster_Params  params;


    /* check glyph image format */
    if ( slot->format != render->glyph_format )
    {
      error = Smooth_Err_Invalid_Argument;
      goto Exit;
    }

    /* check mode */
    if ( mode != required_mode )
      return Smooth_Err_Cannot_Render_Glyph;

    outline = &slot->outline;

    /* translate the outline to the new origin if needed */
    if ( origin )
      FT_Outline_Translate( outline, origin->x, origin->y );

    /* compute the control box, and grid fit it */
    FT_Outline_Get_CBox( outline, &cbox );

    cbox.xMin = FT_PIX_FLOOR( cbox.xMin );
    cbox.yMin = FT_PIX_FLOOR( cbox.yMin );
    cbox.xMax = FT_PIX_CEIL( cbox.xMax );
    cbox.yMax = FT_PIX_CEIL( cbox.yMax );

    width  = (FT_UInt)( ( cbox.xMax - cbox.xMin ) >> 6 );
    height = (FT_UInt)( ( cbox.yMax - cbox.yMin ) >> 6 );
    bitmap = &slot->bitmap;
    memory = render->root.memory;

    width_org  = width;
    height_org = height;

    /* release old bitmap buffer */
    if ( slot->internal->flags & FT_GLYPH_OWN_BITMAP )
    {
      FT_FREE( bitmap->buffer );
       slot->internal->flags &= ~FT_GLYPH_OWN_BITMAP;
     }
 
    /* allocate new one, depends on pixel format */
     pitch = width;
     if ( hmul )
     {
      width = width * 3;
      pitch = FT_PAD_CEIL( width, 4 );
    }

    if ( vmul )
      height *= 3;

    x_shift = (FT_Int) cbox.xMin;
    y_shift = (FT_Int) cbox.yMin;
    x_left  = (FT_Int)( cbox.xMin >> 6 );
    y_top   = (FT_Int)( cbox.yMax >> 6 );

#ifdef FT_CONFIG_OPTION_SUBPIXEL_RENDERING

    if ( slot->library->lcd_filter_func )
    {
      FT_Int  extra = slot->library->lcd_extra;


      if ( hmul )
      {
        x_shift -= 64 * ( extra >> 1 );
        width   += 3 * extra;
        pitch    = FT_PAD_CEIL( width, 4 );
        x_left  -= extra >> 1;
      }

      if ( vmul )
      {
        y_shift -= 64 * ( extra >> 1 );
        height  += 3 * extra;
        y_top   += extra >> 1;
      }
    }
 
 #endif
 
     bitmap->pixel_mode = FT_PIXEL_MODE_GRAY;
     bitmap->num_grays  = 256;
     bitmap->width      = width;
      goto Exit;

    slot->internal->flags |= FT_GLYPH_OWN_BITMAP;

    /* set up parameters */
    params.target = bitmap;
    params.source = outline;
    params.flags  = FT_RASTER_FLAG_AA;

#ifdef FT_CONFIG_OPTION_SUBPIXEL_RENDERING

    /* implode outline if needed */
    {
      FT_Vector*  points     = outline->points;
      FT_Vector*  points_end = points + outline->n_points;
      FT_Vector*  vec;


      if ( hmul )
        for ( vec = points; vec < points_end; vec++ )
          vec->x *= 3;

      if ( vmul )
        for ( vec = points; vec < points_end; vec++ )
          vec->y *= 3;
    }

    /* render outline into the bitmap */
    error = render->raster_render( render->raster, &params );

    /* deflate outline if needed */
    {
      FT_Vector*  points     = outline->points;
      FT_Vector*  points_end = points + outline->n_points;
      FT_Vector*  vec;


      if ( hmul )
        for ( vec = points; vec < points_end; vec++ )
          vec->x /= 3;

      if ( vmul )
        for ( vec = points; vec < points_end; vec++ )
          vec->y /= 3;
    }

    if ( slot->library->lcd_filter_func )
      slot->library->lcd_filter_func( bitmap, mode, slot->library );

#else /* !FT_CONFIG_OPTION_SUBPIXEL_RENDERING */

    /* render outline into bitmap */
    error = render->raster_render( render->raster, &params );

    /* expand it horizontally */
    if ( hmul )
    {
      FT_Byte*  line = bitmap->buffer;
      FT_UInt   hh;


      for ( hh = height_org; hh > 0; hh--, line += pitch )
      {
        FT_UInt   xx;
        FT_Byte*  end = line + width;


        for ( xx = width_org; xx > 0; xx-- )
        {
          FT_UInt  pixel = line[xx-1];


          end[-3] = (FT_Byte)pixel;
          end[-2] = (FT_Byte)pixel;
          end[-1] = (FT_Byte)pixel;
          end    -= 3;
        }
      }
    }

    /* expand it vertically */
    if ( vmul )
    {
      FT_Byte*  read  = bitmap->buffer + ( height - height_org ) * pitch;
      FT_Byte*  write = bitmap->buffer;
      FT_UInt   hh;


      for ( hh = height_org; hh > 0; hh-- )
      {
        ft_memcpy( write, read, pitch );
        write += pitch;

        ft_memcpy( write, read, pitch );
        write += pitch;

        ft_memcpy( write, read, pitch );
        write += pitch;
        read  += pitch;
      }
    }

#endif /* !FT_CONFIG_OPTION_SUBPIXEL_RENDERING */

    FT_Outline_Translate( outline, x_shift, y_shift );

    if ( error )
      goto Exit;

    slot->format      = FT_GLYPH_FORMAT_BITMAP;
    slot->bitmap_left = x_left;
    slot->bitmap_top  = y_top;

  Exit:
    if ( outline && origin )
      FT_Outline_Translate( outline, -origin->x, -origin->y );

    return error;
  }

This weakness involves numeric computation errors, such as integer overflows, underflows, or precision losses, which can lead to miscalculations and exploitable behaviors in software.