TimeSource.cpp

/***************************************************************************
 *                                                                         *
 *   (c) Art Tevs, MPI Informatik Saarbruecken                             *
 *       mailto: <tevs@mpi-sb.mpg.de>                                      *
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/

//----------------------------------------------------------------------------------
// Includes
//----------------------------------------------------------------------------------
#include "TimeSource.h"
#include "Log.h"

#include <time.h>
#if NR_PLATFORM != NR_PLATFORM_WIN32
#    include <sys/time.h>
#endif

namespace nrEngine{
                
        //------------------------------------------------------------------------
        TimeSource::TimeSource() : _currentTime(0), _syncTime(0)
        {
                reset();
        }

        //------------------------------------------------------------------------
        TimeSource::~TimeSource()
        {
        }
                
        //------------------------------------------------------------------------
        float64 TimeSource::getSystemTime()
        {
                // do not use rdtsc for time calculation, just get time
                // by system calls
                timeval now;
                gettimeofday(&now, NULL);

                // some precalculation
                float64 a = static_cast<float64>(now.tv_sec) * static_cast<float64>(1000.0);
                float64 b = static_cast<float64>(now.tv_usec)/ static_cast<float64>(1000.0);

                // clculate the time in seconds
                return  static_cast<float64>(0.001) * (a+b);
                
        }

        //------------------------------------------------------------------------
        float64 TimeSource::getTime()
        {
                // retrive time information
                timeval now;
                gettimeofday(&now, NULL);

                // some precalculation
                float64 a =  static_cast<float64>(now.tv_sec - _startTime.tv_sec) *  static_cast<float64>(1000.0);
                float64 b =  static_cast<float64>(now.tv_usec- _startTime.tv_usec)/  static_cast<float64>(1000.0);
        
                // clculate the time in seconds
                _currentTime =  static_cast<float64>(0.001) * (a+b) + _resetTime + _syncTime;
                
                // return it back
                return _currentTime;
        }

        //------------------------------------------------------------------------
        void TimeSource::reset(float64 startValue)
        {
                gettimeofday(&_startTime, NULL);
                _resetTime = startValue;
        }

        //------------------------------------------------------------------------
        void TimeSource::sync()
        {
                _syncTime = _currentTime;
                reset();
        }

        //------------------------------------------------------------------------
        void TimeSource::notifyNextFrame()
        {
        }
                
}; // end namespace     

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