D:/Programming/GUI Editor (Source)/Timer.cpp

/*
        CTimer.cpp

                Timer class under Microsoft Windows.

        Author: Brett Porter
        Email: brettporter@yahoo.com
        Website: http://rsn.gamedev.net/pl3d
        Copyright (C)2000, 2001, Brett Porter. All Rights Reserved.
        This source code is released under the LGPL. See license.txt for details.

        Created: 18 July 2000
        Last Edited: 6 Febraury 2001

        Please see the file ChangeLog.html for a revision history.
*/

#include "stdafx.h"
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include "Timer.h"

#ifndef _WIN32
#       error   This file should only be used in a Microsoft Windows build.
#endif

// Disable warning about non-standard extension in Microsoft's header files
#pragma warning( disable : 4201 )
#include <mmsystem.h>
#pragma warning( default : 4201 )
#pragma comment( lib, "winmm.lib" )


CTimer::CTimer()
{
        if ( QueryPerformanceFrequency(( LARGE_INTEGER* )&m_dwFrequency ) == false )
        {
                // No performance counter available
                m_bUsePerformanceCounter = false;

                m_dwTimerStart = timeGetTime();
        }
        else
        {
                // Performance counter is available, use it instead of the multimedia timer
                m_bUsePerformanceCounter = true;

                // Get the current time and store it in pcTimerStart
                QueryPerformanceCounter(( LARGE_INTEGER* )&m_dwTimerStart );

                // Calculate the timer resolution using the timer frequency
                m_fResolution = ( float )( 1.0/( double )m_dwFrequency )*1000.0f;
        }

        m_iPauseCount = 0;
        m_fPauseTime = 0;
}

CTimer::~CTimer()
{

}

void CTimer::Reset()
{
        if ( m_bUsePerformanceCounter == true )
                QueryPerformanceCounter(( LARGE_INTEGER* )&m_dwTimerStart );
        else
                m_dwTimerStart = timeGetTime();

        m_fPauseTime = GetTime();
}

double CTimer::GetTime()
{
        if ( m_iPauseCount > 0 )
                return m_fPauseTime;

        __int64 timeElapsed;

        if ( m_bUsePerformanceCounter == true )
        {
                QueryPerformanceCounter(( LARGE_INTEGER* )&timeElapsed );
                timeElapsed -= m_dwTimerStart;
                return timeElapsed*m_fResolution;
        }
        else
        {
                timeElapsed = timeGetTime()-m_dwTimerStart;
                return ( double )timeElapsed;
        }
}

void CTimer::Pause()
{
        if ( m_iPauseCount == 0 )
                m_fPauseTime = GetTime();

        m_iPauseCount++;
}


double CTimer::GetAbsoluteTime()
{
        __int64 timeElapsed;
        if ( m_bUsePerformanceCounter == true )
                QueryPerformanceCounter(( LARGE_INTEGER* )&timeElapsed );
        
        else
                timeElapsed = timeGetTime();

        return timeElapsed*m_fResolution;
}

void CTimer::Unpause()
{
        if(m_iPauseCount > 0 )
                m_iPauseCount--;

        if ( m_iPauseCount == 0 )
        {
                if ( m_bUsePerformanceCounter == true )
                {
                        __int64 time;
                        QueryPerformanceCounter(( LARGE_INTEGER* )&time );
                        m_dwTimerStart = time - ( __int64 )( m_fPauseTime/m_fResolution );
                }
                else
                {
                        m_dwTimerStart = ( unsigned )( timeGetTime() - m_fPauseTime );
                }
        }
}

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