Magic_Game/core/Base/Time.cpp

#include "..\ebase.h"
#include <thread>
#include <chrono>
using namespace std::chrono;


// <20><>Ϸ<EFBFBD><CFB7>ʼʱ<CABC><CAB1>
static steady_clock::time_point s_tStart;
// <20><>ǰʱ<C7B0><CAB1>
static steady_clock::time_point s_tNow;
// <20><>һ֡ˢ<D6A1><CBA2>ʱ<EFBFBD><CAB1>
static steady_clock::time_point s_tFixedUpdate;
// <20><>һ<EFBFBD>θ<EFBFBD><CEB8><EFBFBD>ʱ<EFBFBD><CAB1>
static steady_clock::time_point s_tLastUpdate;
// <20><>һ֡<D2BB>뵱ǰ֡<C7B0><D6A1>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
static int s_nInterval = 0;
// <20><>Ϸ<EFBFBD><CFB7>ʼʱ<CABC><CAB1>
static float s_fTotalTime = 0;
// ÿһ֡<D2BB><D6A1><EFBFBD><EFBFBD>
static milliseconds s_tExceptedInvertal;


float e2d::Time::getTotalTime()
{
	return s_fTotalTime;
}

int e2d::Time::getDeltaTime()
{
	return s_nInterval;
}

bool e2d::Time::__init()
{
	s_tStart = s_tLastUpdate = s_tFixedUpdate = s_tNow = steady_clock::now();
	s_tExceptedInvertal = milliseconds(17);
	return true;
}

void e2d::Time::__uninit()
{
}

bool e2d::Time::__isReady()
{
	return s_tExceptedInvertal < duration_cast<milliseconds>(s_tNow - s_tFixedUpdate);
}

void e2d::Time::__updateNow()
{
	// ˢ<><CBA2>ʱ<EFBFBD><CAB1>
	s_tNow = steady_clock::now();
}

void e2d::Time::__updateLast()
{
	s_tFixedUpdate += s_tExceptedInvertal;
	s_tLastUpdate = s_tNow;

	s_tNow = steady_clock::now();
	s_nInterval = static_cast<int>(duration_cast<milliseconds>(s_tNow - s_tLastUpdate).count());
	s_fTotalTime = static_cast<float>(duration_cast<milliseconds>(s_tNow - s_tStart).count()) / 1000.0f;
}

void e2d::Time::__sleep()
{
	// <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1>
	int nWaitMS = 16 - static_cast<int>(duration_cast<milliseconds>(s_tNow - s_tFixedUpdate).count());
	
	if (nWaitMS > 1)
	{
		// <20><><EFBFBD><EFBFBD><EFBFBD>̣߳<DFB3><CCA3>ͷ<EFBFBD> CPU ռ<><D5BC>
		std::this_thread::sleep_for(milliseconds(nWaitMS));
	}
}