genode/repos/demo/include/scout/graphics_backend.h

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/*
* \brief Graphics backend interface
* \date 2013-12-30
* \author Norman Feske
*/
/*
* Copyright (C) 2013 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
#ifndef _INCLUDE__SCOUT__GRAPHICS_BACKEND_H_
#define _INCLUDE__SCOUT__GRAPHICS_BACKEND_H_
#include <scout/event.h>
#include <scout/canvas.h>
namespace Scout { struct Graphics_backend; }
/*
* We use two buffers, a foreground buffer that is displayed on screen and a
* back buffer. While the foreground buffer must contain valid data all the
* time, the back buffer can be used to prepare pixel data. For example,
* drawing multiple pixel layers with alpha channel must be done in the back
* buffer to avoid artifacts on the screen.
*/
struct Scout::Graphics_backend
{
virtual Canvas_base &front() = 0;
virtual Canvas_base &back() = 0;
virtual void copy_back_to_front(Rect rect) = 0;
virtual void swap_back_and_front() = 0;
/*
* XXX todo mode-change notification
*/
virtual void position(Point p) = 0;
virtual void bring_to_front() = 0;
virtual void view_area(Area area) = 0;
};
#endif /* _INCLUDE__SCOUT__GRAPHICS_BACKEND_H_ */