diff --git a/core/Base/Game.cpp b/core/Base/Game.cpp
index be9d983d..33262ea7 100644
--- a/core/Base/Game.cpp
+++ b/core/Base/Game.cpp
@@ -3,8 +3,6 @@
 #include "..\e2dtool.h"
 #include <thread>
 
-using namespace std::chrono;
-
 
 e2d::Game * e2d::Game::_instance = nullptr;
 
@@ -42,13 +40,8 @@ void e2d::Game::destroyInstance()
 
 void e2d::Game::start()
 {
-	HWND hWnd = Window::getInstance()->getHWnd();
-	if (hWnd == nullptr)
-	{
-		throw SystemException(L"无法创建窗口");
-	}
-
 	// 显示窗口
+	HWND hWnd = Window::getInstance()->getHWnd();
 	::ShowWindow(hWnd, SW_SHOWNORMAL);
 	::UpdateWindow(hWnd);
 
@@ -61,7 +54,7 @@ void e2d::Game::start()
 
 	_quit = false;
 	_last = _now = Time::now();
-
+	
 	while (!_quit)
 	{
 		_now = Time::now();
@@ -70,30 +63,21 @@ void e2d::Game::start()
 		if (_config.isVSyncEnabled() || _frameInterval < interval)
 		{
 			_last = _now;
-			__update();
+			Input::getInstance()->update();
+			Timer::getInstance()->update();
+			ActionManager::getInstance()->update();
+			SceneManager::getInstance()->update();
+			Renderer::getInstance()->render();
+			Window::getInstance()->poll();
+			GC::getInstance()->flush();
 		}
 		else
 		{
-			wait = (_frameInterval - interval).milliseconds() - 1;
-			if (wait > 1)
-			{
-				std::this_thread::sleep_for(milliseconds(wait));
-			}
+			std::this_thread::yield();
 		}
 	}
 }
 
-void e2d::Game::__update()
-{
-	Input::getInstance()->update();
-	Timer::getInstance()->update();
-	ActionManager::getInstance()->update();
-	SceneManager::getInstance()->update();
-	Renderer::getInstance()->render();
-	Window::getInstance()->poll();
-	GC::getInstance()->flush();
-}
-
 void e2d::Game::pause()
 {
 	_paused = true;
@@ -133,7 +117,6 @@ void e2d::Game::setConfig(const Config& config)
 	if (_config.isVSyncEnabled() != config.isVSyncEnabled())
 	{
 		Renderer::getInstance()->discardDeviceResources();
-		_last = _now;
 	}
 
 	_config = config;
diff --git a/core/Common/Duration.cpp b/core/Common/Duration.cpp
index ef691efe..0e672f65 100644
--- a/core/Common/Duration.cpp
+++ b/core/Common/Duration.cpp
@@ -66,3 +66,15 @@ e2d::Duration e2d::Duration::operator-(Duration const & other) const
 {
 	return std::move(Duration(_ms - other._ms));
 }
+
+e2d::Duration & e2d::Duration::operator+=(Duration const &other)
+{
+	_ms += other._ms;
+	return (*this);
+}
+
+e2d::Duration & e2d::Duration::operator-=(Duration const &other)
+{
+	_ms -= other._ms;
+	return (*this);
+}
diff --git a/core/Common/Time.cpp b/core/Common/Time.cpp
index a5c03744..6a2bfc4d 100644
--- a/core/Common/Time.cpp
+++ b/core/Common/Time.cpp
@@ -7,15 +7,20 @@ e2d::Time::Time()
 {
 }
 
-e2d::Time::Time(const std::chrono::steady_clock::time_point& time)
+e2d::Time::Time(const steady_clock::time_point& time)
 	: _timePoint(time)
 {
 }
 
 time_t e2d::Time::getTimeStamp() const
 {
-	auto& now = time_point_cast<milliseconds>(_timePoint).time_since_epoch();
-	return static_cast<time_t>(now.count());
+	auto& duration = time_point_cast<milliseconds>(_timePoint).time_since_epoch();
+	return static_cast<time_t>(duration.count());
+}
+
+bool e2d::Time::isZero() const
+{
+	return _timePoint.time_since_epoch().count() == 0LL;
 }
 
 e2d::Time e2d::Time::operator+(Duration const & other) const
@@ -29,6 +34,17 @@ e2d::Time & e2d::Time::operator+=(Duration const & other)
 	return (*this);
 }
 
+e2d::Time e2d::Time::operator-(Duration const & other) const
+{
+	return std::move(Time(_timePoint - milliseconds(other.milliseconds())));
+}
+
+e2d::Time & e2d::Time::operator-=(Duration const &other)
+{
+	_timePoint -= milliseconds(other.milliseconds());
+	return (*this);
+}
+
 e2d::Duration e2d::Time::operator-(Time const & other) const
 {
 	auto& ms = duration_cast<milliseconds>(_timePoint - other._timePoint);
diff --git a/core/e2dbase.h b/core/e2dbase.h
index c7df7890..223f0710 100644
--- a/core/e2dbase.h
+++ b/core/e2dbase.h
@@ -148,8 +148,6 @@ private:
 
 	E2D_DISABLE_COPY(Game);
 
-	void __update();
-
 private:
 	bool		_quit;
 	bool		_paused;
diff --git a/core/e2dcommon.h b/core/e2dcommon.h
index 66ad39c5..7f5641f0 100644
--- a/core/e2dcommon.h
+++ b/core/e2dcommon.h
@@ -434,8 +434,11 @@ public:
 	bool operator< (const Duration &) const;
 	bool operator<= (const Duration &) const;
 
-	Duration operator + (Duration const & other) const;
-	Duration operator - (Duration const & other) const;
+	Duration operator + (Duration const &) const;
+	Duration operator - (Duration const &) const;
+
+	Duration& operator += (Duration const &);
+	Duration& operator -= (Duration const &);
 
 protected:
 	std::chrono::milliseconds _ms;
@@ -455,10 +458,16 @@ public:
 	// 获取时间戳
 	time_t getTimeStamp() const;
 
-	Time operator + (Duration const & other) const;
+	// 是否是
+	bool isZero() const;
+
+	Time operator + (Duration const &) const;
+	Time operator - (Duration const &) const;
+
 	Time& operator += (Duration const &);
+	Time& operator -= (Duration const &);
 	
-	Duration operator - (Time const & other) const;
+	Duration operator - (Time const &) const;
 
 	// 获取当前时间
 	static Time now();