/*
 * Copyright (c) 2009 Ian C. Bullard
 * 
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 * 
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

class GameRand
{
public:
	GameRand() : m_high(1), m_low(1 ^ 0x49616E42) {}
	GameRand(unsigned int seed) : m_high(seed), m_low(seed ^ 0x49616E42) {}
	GameRand(unsigned int high, unsigned int low) : m_high(high), m_low(low) {}
	GameRand(const GameRand& rnd) : m_high(rnd.m_high), m_low(rnd.m_low) {}
	
	GameRand& operator=(const GameRand& rnd)
	{
		m_high = rnd.m_high;
		m_low = rnd.m_low;
		
		return *this;
	}
	
	void Seed(unsigned int seed)
	{
		m_high = seed;
		m_low = seed ^ 0x49616E42;
	}
	
	void Seed(unsigned int high, unsigned int low)
	{
		m_high = high;
		m_low = low;
	}
	
	void GetSeed(unsigned int& high, unsigned int& low)
	{
		high = m_high;
		low = m_low;
	}
	
	unsigned int Random()
	{
		m_high = (m_high << 16) + (m_high >> 16);
		m_high += m_low;
		m_low += m_high;
		
		return m_high;
	}
	
	unsigned int operator()()
	{
		return Random();
	}
	
private:
	unsigned int m_high;
	unsigned int m_low;
};