Fl_Image_Surface(int w, int h, int highres=0);

function Create
       (W, H    : in Integer;
        Highres : in Boolean := False)
    return Image_Surface;

const char * class_name();

void draw(Fl_Widget *, int delta_x=0, int delta_y=0);

procedure Draw_Widget
       (This               : in out Image_Surface;
        Item               : in     FLTK.Widgets.Widget'Class;
        Offset_X, Offset_Y : in     Integer := 0);

void draw_decorated_window(Fl_Window *win, int delta_x=0, int delta_y=0);

procedure Draw_Decorated_Window
       (This               : in out Image_Surface;
        Item               : in     FLTK.Widgets.Groups.Windows.Window'Class;
        Offset_X, Offset_Y : in     Integer := 0);

Fl_Shared_Image * highres_image();

function Get_Highres_Image
       (This : in Image_Surface)
    return FLTK.Images.Shared.Shared_Image;

Fl_RGB_Image * image();

function Get_Image
       (This : in Image_Surface)
    return FLTK.Images.RGB.RGB_Image;

void set_current();

procedure Set_Current
       (This : in out Image_Surface);