clock.hpp

// Meteor - A Nintendo Gameboy Advance emulator
// Copyright (C) 2009-2011 Philippe Daouadi
//
// 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 3 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.  If not, see <http://www.gnu.org/licenses/>.

#ifndef __CLOCK_H__
#define __CLOCK_H__

#include <stdint.h>
#include <climits>
#include <vector>
#include <istream>
#include <ostream>

namespace AMeteor
{
	class Clock
	{
		public :
			Clock ()
			{
				Reset();
			}

			void Reset ();

			void ResetCounter()
			{
				m_count = 0;
			}
			unsigned int GetCounter() const
			{
				return m_count;
			}

			void TimePass (unsigned short cycles)
			{
				m_cycles += cycles;
			}
			void Commit ();
			void WaitForNext ();

			void AddLcd (uint32_t cycles)
			{
				// The lcd clock is always enabled
				m_lcd += cycles;
				SetFirst();
			}

			void AddTimer (uint8_t num, uint32_t cycles)
			{
				if (m_timer[num] == INT_MAX)
					m_timer[num] = cycles;
				else
					m_timer[num] += cycles;
				SetFirst();
			}
			void SetTimer (uint8_t num, uint32_t cycles)
			{
				m_timer[num] = cycles;
				SetFirst();
			}
			void DisableTimer (uint8_t num)
			{
				m_timer[num] = INT_MAX;
				SetFirst();
			}
			int GetTimer (uint8_t num)
			{
				return m_timer[num];
			}

			//void SetBattery (uint32_t cycles)
			//{
			//	m_battery = cycles;
			//}
			//void DisableBattery ()
			//{
			//	m_battery = INT_MAX;
				// no need to SetFirst since battery will be disabled only in TimeEvent
			//}

			bool SaveState (std::ostream& stream);
			bool LoadState (std::istream& stream);

		private :
			// XXX freq
			static const int SOUND_PERIOD = 380;

			unsigned short m_cycles;
			unsigned short m_first;
			int m_lcd, m_timer[4], m_sound;//, m_battery;

			unsigned int m_count;

			void SetFirst ();
	};
}

#endif