path: root/src/menu/clipping_helper.hpp

/*
 * UltraStar Deluxe - Karaoke Game
 *
 * UltraStar Deluxe is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING. If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */

#ifndef CLIPPING_HELPER_HPP
#define CLIPPING_HELPER_HPP

#include <GL/gl.h>
#include <log4cpp/Category.hh>

#include "utils/rectangle.hpp"
#include "container.hpp"

namespace usdx
{
	/**
	 * ClippingHelper is a class for handling multiple nested clipping areas. It
	 * handles the set up (during construction) and the tear down (during
	 * deconstruction) of the new clipping. It also preserves the clipping
	 * settings before using this class.
	 *
	 * This class is perfeclty suited for using it in a single scope to cleanup
	 * the new clipping at the end of the current scope.
	 */
	class ClippingHelper
	{
	private:
		static log4cpp::Category& log;

		/**
		 * Whether clipping was enabled before it is setup by this helper. If it
		 * was enabled, it should not be disabled afterwards and the resulting
		 * clipping rectangle should be the intersection between the old and the
		 * new clipping area.
		 */
		GLboolean was_enabled;

		/**
		 * Buffer to cache the old clipping area and resore if afterwards.
		 */
		GLint scissor_box[4];

		/**
		 * Helper to create a Rectangle<int> object out of an GLint array. This
		 * array is returned by glGetIntegerv with GL_SCISSOR_BOX. The helper is
		 * used for converting the OpenGL array to the common internal format.
		 */
		static Rectangle<int> makeRect(GLint box[4]);

	public:
		ClippingHelper(const Container*, const Rectangle<int>&);
		virtual ~ClippingHelper();
	};
}

#endif