virtual void draw_surface_part(const DrawingRequest& request) = 0;
virtual void draw_gradient(const DrawingRequest& request) = 0;
virtual void draw_filled_rect(const DrawingRequest& request)= 0;
virtual void draw_surface_part(const DrawingRequest& request) = 0;
virtual void draw_gradient(const DrawingRequest& request) = 0;
virtual void draw_filled_rect(const DrawingRequest& request)= 0;