class drawable :
?overloaded:[ `draw ] -> Drawable.t ->
Drawable is a very simple base class that allows objects of derived classes to be drawn to a RenderTarget.
All you have to do in your derived class is to override the draw virtual function.
Note that inheriting from Drawable is not mandatory, but it allows
this nice syntax "window#draw(object)" rather than
"object#draw(window)", which is more consistent with other SFML
method rep__sf_Drawable :
method private draw :
texture -> shader -> unit