Core: Added frame limiter

Core/Console.cpp

@@ -13,9 +13,11 @@
 #include "VideoDecoder.h"
 #include "VideoRenderer.h"
 #include "DebugHud.h"
+#include "FrameLimiter.h"
 #include "MessageManager.h"
 #include "../Utilities/Timer.h"
 #include "../Utilities/VirtualFile.h"
+#include "../Utilities/PlatformUtilities.h"
 
 void Console::Initialize()
 {
@@ -49,11 +51,24 @@ void Console::Run()
 	}
 
 	_stopFlag = false;
+	uint32_t previousFrameCount = 0;
+	
+	FrameLimiter frameLimiter(16.63926405550947);
+
+	PlatformUtilities::EnableHighResolutionTimer();
 
 	auto lock = _runLock.AcquireSafe();
 	while(!_stopFlag) {
 		_cpu->Exec();
+
+		if(previousFrameCount != _ppu->GetFrameCount()) {
+			frameLimiter.ProcessFrame();
+			frameLimiter.WaitForNextFrame();
+			previousFrameCount = _ppu->GetFrameCount();
 		}
+	}
+
+	PlatformUtilities::RestoreTimerResolution();
 }
 
 void Console::Stop()

Core/Core.vcxproj

@@ -70,6 +70,7 @@
     <ClInclude Include="DrawScreenBufferCommand.h" />
     <ClInclude Include="DrawStringCommand.h" />
     <ClInclude Include="dsp.h" />
+    <ClInclude Include="FrameLimiter.h" />
     <ClInclude Include="IAudioDevice.h" />
     <ClInclude Include="IInputProvider.h" />
     <ClInclude Include="IInputRecorder.h" />

Core/Core.vcxproj.filters

@@ -170,6 +170,9 @@
     <ClInclude Include="ControlManager.h">
       <Filter>SNES\Input</Filter>
     </ClInclude>
+    <ClInclude Include="FrameLimiter.h">
+      <Filter>SNES</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="stdafx.cpp" />

Core/FrameLimiter.h

@@ -0,0 +1,45 @@
+#pragma once
+#include "../Utilities/Timer.h"
+
+class FrameLimiter
+{
+private:
+	Timer _clockTimer;
+	double _targetTime;
+	double _delay;
+	bool _resetRunTimers;
+
+public:
+	FrameLimiter(double delay)
+	{
+		_delay = delay;
+		_targetTime = _delay;
+	}
+
+	void SetDelay(double delay)
+	{
+		_delay = delay;
+		_resetRunTimers = true;
+	}
+
+	void ProcessFrame()
+	{
+		if(_resetRunTimers || (_clockTimer.GetElapsedMS() - _targetTime) > 300) {
+			//Reset the timers, this can happen in 3 scenarios:
+			//1) Target frame rate changed
+			//2) The console was reset/power cycled or the emulation was paused (with or without the debugger)
+			//3) As a satefy net, if we overshoot our target by over 300 milliseconds, the timer is reset, too.
+			//   This can happen when something slows the emulator down severely (or when breaking execution in VS when debugging Mesen itself, etc.)
+			_clockTimer.Reset();
+			_targetTime = 0;
+			_resetRunTimers = false;
+		}
+
+		_targetTime += _delay;
+	}
+
+	void WaitForNextFrame()
+	{
+		_clockTimer.WaitUntil(_targetTime);
+	}
+};