Input: Ensure input is always processed at the same moment on each frame (first cycle of NMI scanline)

Before this, DMA transfers could delay input processing for a long time (potentially multiple frames)

Core/Console.cpp

@@ -31,6 +31,7 @@
 #include "BatteryManager.h"
 #include "CheatManager.h"
 #include "MovieManager.h"
+#include "SystemActionManager.h"
 #include "SpcHud.h"
 #include "../Utilities/Serializer.h"
 #include "../Utilities/Timer.h"
@@ -96,14 +97,9 @@ void Console::Run()
 	
 	auto emulationLock = _emulationLock.AcquireSafe();
 	auto lock = _runLock.AcquireSafe();
-
-	DebugStats stats(this);
-	Timer lastFrameTimer;
-	_stopFlag = false;
 	uint32_t previousFrameCount = 0;
-	
-	double frameDelay = GetFrameDelay();
-	FrameLimiter frameLimiter(frameDelay);
+
+	_stopFlag = false;
 
 	PlatformUtilities::EnableHighResolutionTimer();
 
@@ -113,15 +109,15 @@ void Console::Run()
 	_memoryManager->IncMasterClockStartup();
 	_controlManager->UpdateInputState();
 
+	_frameDelay = GetFrameDelay();
+	_stats.reset(new DebugStats());
+	_frameLimiter.reset(new FrameLimiter(_frameDelay));
+	_lastFrameTimer.Reset();
+
 	while(!_stopFlag) {
 		_cpu->Exec();
 
 		if(previousFrameCount != _ppu->GetFrameCount()) {
-			_cart->RunCoprocessors();
-			if(_cart->GetCoprocessor()) {
-				_cart->GetCoprocessor()->ProcessEndOfFrame();
-			}
-
 			_rewindManager->ProcessEndOfFrame();
 
 			WaitForLock();
@@ -133,32 +129,14 @@ void Console::Run()
 
 			if(_paused && !_stopFlag && !_debugger) {
 				WaitForPauseEnd();
-				if(_stopFlag) {
-					break;
-				}
 			}
-
-			frameLimiter.ProcessFrame();
-			frameLimiter.WaitForNextFrame();
-
-			double newFrameDelay = GetFrameDelay();
-			if(newFrameDelay != frameDelay) {
-				frameDelay = newFrameDelay;
-				frameLimiter.SetDelay(frameDelay);
-			}
-			
-			PreferencesConfig cfg = _settings->GetPreferences();
-			if(cfg.ShowDebugInfo) {
-				double lastFrameTime = lastFrameTimer.GetElapsedMS();
-				lastFrameTimer.Reset();
-				stats.DisplayStats(lastFrameTime);
-			}
-
-			_controlManager->UpdateInputState();
-			_controlManager->UpdateControlDevices();
-			_internalRegisters->ProcessAutoJoypadRead();
-			
 			previousFrameCount = _ppu->GetFrameCount();
+
+			if(_controlManager->GetSystemActionManager()->IsResetPressed()) {
+				Reset();
+			} else if(_controlManager->GetSystemActionManager()->IsPowerCyclePressed()) {
+				PowerCycle();
+			}
 		}
 	}
 
@@ -169,6 +147,36 @@ void Console::Run()
 	PlatformUtilities::RestoreTimerResolution();
 }
 
+void Console::ProcessEndOfFrame()
+{
+#ifndef LIBRETRO
+	_cart->RunCoprocessors();
+	if(_cart->GetCoprocessor()) {
+		_cart->GetCoprocessor()->ProcessEndOfFrame();
+	}
+
+	_frameLimiter->ProcessFrame();
+	_frameLimiter->WaitForNextFrame();
+
+	double newFrameDelay = GetFrameDelay();
+	if(newFrameDelay != _frameDelay) {
+		_frameDelay = newFrameDelay;
+		_frameLimiter->SetDelay(_frameDelay);
+	}
+
+	PreferencesConfig cfg = _settings->GetPreferences();
+	if(cfg.ShowDebugInfo) {
+		double lastFrameTime = _lastFrameTimer.GetElapsedMS();
+		_lastFrameTimer.Reset();
+		_stats->DisplayStats(this, lastFrameTime);
+	}
+
+	_controlManager->UpdateInputState();
+	_controlManager->UpdateControlDevices();
+	_internalRegisters->ProcessAutoJoypadRead();
+#endif
+}
+
 void Console::RunSingleFrame()
 {
 	//Used by Libretro

Core/Console.h

@@ -3,6 +3,7 @@
 #include "CartTypes.h"
 #include "DebugTypes.h"
 #include "ConsoleLock.h"
+#include "../Utilities/Timer.h"
 #include "../Utilities/VirtualFile.h"
 #include "../Utilities/SimpleLock.h"
 
@@ -27,6 +28,9 @@ class BatteryManager;
 class CheatManager;
 class MovieManager;
 class SpcHud;
+class FrameLimiter;
+class DebugStats;
+
 enum class MemoryOperationType;
 enum class SnesMemoryType;
 enum class EventType;
@@ -75,6 +79,11 @@ private:
 	ConsoleRegion _region;
 	uint32_t _masterClockRate;
 
+	unique_ptr<DebugStats> _stats;
+	unique_ptr<FrameLimiter> _frameLimiter;
+	Timer _lastFrameTimer;
+	double _frameDelay = 0;
+
 	double GetFrameDelay();
 	void UpdateRegion();
 	void WaitForLock();
@@ -91,6 +100,8 @@ public:
 	void RunSingleFrame();
 	void Stop(bool sendNotification);
 
+	void ProcessEndOfFrame();
+
 	void Reset();
 	void PowerCycle();
 

Core/ControlManager.cpp

@@ -70,9 +70,9 @@ vector<ControllerData> ControlManager::GetPortStates()
 	return states;
 }
 
-shared_ptr<SystemActionManager> ControlManager::GetSystemActionManager()
+SystemActionManager* ControlManager::GetSystemActionManager()
 {
-	return _systemActionManager;
+	return _systemActionManager.get();
 }
 
 shared_ptr<BaseControlDevice> ControlManager::GetControlDevice(uint8_t port)
@@ -134,7 +134,6 @@ void ControlManager::UpdateControlDevices()
 			}
 		}
 	}
-	_systemActionManager->ProcessSystemActions();
 }
 
 void ControlManager::UpdateInputState()

Core/ControlManager.h

@@ -51,7 +51,7 @@ public:
 
 	vector<ControllerData> GetPortStates();
 
-	shared_ptr<SystemActionManager> GetSystemActionManager();
+	SystemActionManager* GetSystemActionManager();
 	shared_ptr<BaseControlDevice> GetControlDevice(uint8_t port);
 	vector<shared_ptr<BaseControlDevice>> GetControlDevices();
 	

Core/DebugStats.cpp

@@ -7,21 +7,16 @@
 #include "DebugHud.h"
 #include "IAudioDevice.h"
 
-DebugStats::DebugStats(Console * console)
+void DebugStats::DisplayStats(Console *console, double lastFrameTime)
 {
-	_console = console;
-}
-
-void DebugStats::DisplayStats(double lastFrameTime)
-{
-	AudioStatistics stats = _console->GetSoundMixer()->GetStatistics();
-	AudioConfig audioCfg = _console->GetSettings()->GetAudioConfig();
-	shared_ptr<DebugHud> hud = _console->GetDebugHud();
+	AudioStatistics stats = console->GetSoundMixer()->GetStatistics();
+	AudioConfig audioCfg = console->GetSettings()->GetAudioConfig();
+	shared_ptr<DebugHud> hud = console->GetDebugHud();
 
 	_frameDurations[_frameDurationIndex] = lastFrameTime;
 	_frameDurationIndex = (_frameDurationIndex + 1) % 60;
 
-	int startFrame = _console->GetPpu()->GetFrameCount();
+	int startFrame = console->GetPpu()->GetFrameCount();
 
 	hud->DrawRectangle(8, 8, 115, 49, 0x40000000, true, 1, startFrame);
 	hud->DrawRectangle(8, 8, 115, 49, 0xFFFFFF, false, 1, startFrame);
@@ -36,7 +31,7 @@ void DebugStats::DisplayStats(double lastFrameTime)
 
 	hud->DrawString(10, 30, "Underruns: " + std::to_string(stats.BufferUnderrunEventCount), 0xFFFFFF, 0xFF000000, 1, startFrame);
 	hud->DrawString(10, 39, "Buffer Size: " + std::to_string(stats.BufferSize / 1024) + "kb", 0xFFFFFF, 0xFF000000, 1, startFrame);
-	hud->DrawString(10, 48, "Rate: " + std::to_string((uint32_t)(audioCfg.SampleRate *  _console->GetSoundMixer()->GetRateAdjustment())) + "Hz", 0xFFFFFF, 0xFF000000, 1, startFrame);
+	hud->DrawString(10, 48, "Rate: " + std::to_string((uint32_t)(audioCfg.SampleRate *  console->GetSoundMixer()->GetRateAdjustment())) + "Hz", 0xFFFFFF, 0xFF000000, 1, startFrame);
 
 	hud->DrawRectangle(132, 8, 115, 49, 0x40000000, true, 1, startFrame);
 	hud->DrawRectangle(132, 8, 115, 49, 0xFFFFFF, false, 1, startFrame);
@@ -55,7 +50,7 @@ void DebugStats::DisplayStats(double lastFrameTime)
 	ss << "Last Frame: " << std::fixed << std::setprecision(2) << lastFrameTime << " ms";
 	hud->DrawString(134, 30, ss.str(), 0xFFFFFF, 0xFF000000, 1, startFrame);
 
-	if(_console->GetPpu()->GetFrameCount() > 60) {
+	if(console->GetPpu()->GetFrameCount() > 60) {
 		_lastFrameMin = std::min(lastFrameTime, _lastFrameMin);
 		_lastFrameMax = std::max(lastFrameTime, _lastFrameMax);
 	} else {

Core/DebugStats.h

@@ -6,14 +6,11 @@ class Console;
 class DebugStats
 {
 private:
-	Console *_console;
 	double _frameDurations[60] = {};
 	uint32_t _frameDurationIndex = 0;
 	double _lastFrameMin = 9999;
 	double _lastFrameMax = 0;
 
 public:
-	DebugStats(Console *console);
-
-	void DisplayStats(double lastFrameTime);
+	void DisplayStats(Console *console, double lastFrameTime);
 };

Core/Ppu.cpp

@@ -467,6 +467,8 @@ bool Ppu::ProcessEndOfScanline(uint16_t hClock)
 			_regs->SetNmiFlag(true);
 			SendFrame();
 
+			_console->ProcessEndOfFrame();
+
 			if(_regs->IsNmiEnabled()) {
 				_console->GetCpu()->SetNmiFlag();
 			}

Core/SystemActionManager.h

@@ -79,16 +79,13 @@ public:
 		return false;
 	}
 
-	void ProcessSystemActions()
+	bool IsResetPressed()
 	{
-		if(_console) {
-			if(IsPressed(SystemActionManager::Buttons::ResetButton)) {
-				_console->Reset();
-			}
-			if(IsPressed(SystemActionManager::Buttons::PowerButton)) {
-				_console->PowerCycle();
-				//Calling PowerCycle() causes this object to be deleted - no code must be written below this line
-			}
-		}
+		return IsPressed(SystemActionManager::Buttons::ResetButton);
 	}
-};
+
+	bool IsPowerCyclePressed()
+	{
+		return IsPressed(SystemActionManager::Buttons::PowerButton);
+	}
+};