CLASSE TIMER SOUS WINDOWS ( CHRONOMÈTRE )

#include <windows.h>
#include <mmsystem.h>

/***** Déclaration de la classe *****/

class Timer
{

	LONGLONG	start_time;
	LONGLONG	cur_time;
	LONGLONG	last_time;
	float		time_elapsed;
	float		time_scale;

	typedef float (DXPTimer::*Func)();
	Func UpdateFunc;

	float GetTimePerf();
	float GetTime();

public:

	Timer();                                 // Constructeur
	~Timer();                               // Destructeur
	
	void Start();                            // Initialisation du timer
	float GetTotalElapsedTime();     // Temps écoulé depuis l'initialisation du timer
	float GetElapsedTime();            // Temps écoulé entre deux appels de la fonction

};

/***** Description des méthodes de la classe *****/

Timer::Timer()
{

}

Timer::~Timer()
{

}

void Timer::Start()
{
	LONGLONG	perf_cnt = 0;

	if (QueryPerformanceFrequency((LARGE_INTEGER *) &perf_cnt))
	{
		time_scale = 1.0f / perf_cnt;
		QueryPerformanceCounter((LARGE_INTEGER *) &start_time);
		last_time = start_time;
		this->UpdateFunc = &Timer::GetTimePerf;
	}
	else
	{ 
		start_time = last_time = timeGetTime();
		time_scale = 0.001f;
		this->UpdateFunc = &Timer::GetTime;
	}
}

float Timer::GetTime()
{
	return (float)timeGetTime();
}

float Timer::GetTimePerf()
{
	QueryPerformanceCounter((LARGE_INTEGER *) &cur_time);
	
	return (float)cur_time;
}

float Timer::GetTotalElapsedTime()
{
	cur_time = (this->*UpdateFunc)();

	time_elapsed = (cur_time - start_time) * time_scale;
	last_time = cur_time;

	return time_elapsed;
}

float Timer::GetElapsedTime()
{
	cur_time = (this->*UpdateFunc)();

	time_elapsed = (cur_time - last_time) * time_scale;
	last_time = cur_time;

	return time_elapsed;
}