ReplaceFramelimiter: implements new reduced-CPU-usage limiter

dllmain/DisplayTweaks.cpp

@@ -3,6 +3,7 @@
 #include "Patches.h"
 #include "Game.h"
 #include "Settings.h"
+#include <timeapi.h>
 
 int g_UserRefreshRate;
 
@@ -76,8 +77,112 @@ BOOL __stdcall MoveWindow_Hook(HWND hWnd, int X, int Y, int nWidth, int nHeight,
 	return MoveWindow(hWnd, windowX, windowY, nWidth, nHeight, bRepaint);
 }
 
+double FramelimiterFrequency = 0;
+double FramelimiterPrevTicks = 0;
+void Framelimiter_Hook(uint8_t isAliveEvt_result)
+{
+	// Change thread to core 0 before running QueryPerformance* funcs, game does this, so guess we should too
+	HANDLE curThread = GetCurrentThread();
+	DWORD_PTR prevAffinityMask = SetThreadAffinityMask(curThread, 0);
+
+	static bool framelimiterInited = false;
+	if (!framelimiterInited)
+	{
+		LARGE_INTEGER result;
+		QueryPerformanceFrequency(&result);
+		FramelimiterFrequency = (double)result.QuadPart / 1000.0;
+
+		QueryPerformanceCounter(&result);
+		FramelimiterPrevTicks = (double)result.QuadPart / FramelimiterFrequency;
+
+		typedef MMRESULT(__stdcall* timeBeginPeriod_Fn) (UINT Period);
+		timeBeginPeriod_Fn timeBeginPeriod_actual = (timeBeginPeriod_Fn)GetProcAddress(LoadLibraryA("winmm.dll"), "timeBeginPeriod");
+		timeBeginPeriod_actual(1);
+
+		framelimiterInited = true;
+	}
+
+	int gameFramerate = GameVariableFrameRate();
+
+	// The games IsAliveEvt check seems to (indirectly) result in framelimiter loop limiting to 60FPS
+	// maybe a remnant of some time when more framerate options were available?
+	if (isAliveEvt_result && gameFramerate != 30)
+		gameFramerate = 60;
+
+	double TargetFrametime = 1000.0 / (double)gameFramerate;
+
+	double timeElapsed = 0;
+	double timeCurrent = 0;
+	do
+	{
+		// Framelimiter based on FPS_ACCURATE code from
+		// https://github.com/ThirteenAG/d3d9-wrapper/blob/c1480b0c1b40e0ba7b55b8660bd67f911a967421/source/dllmain.cpp#L46
+
+		LARGE_INTEGER counter;
+		QueryPerformanceCounter(&counter);
+		timeCurrent = (double)counter.QuadPart / FramelimiterFrequency;
+		timeElapsed = timeCurrent - FramelimiterPrevTicks;
+
+		if (TargetFrametime <= timeElapsed || pConfig->bDisableFramelimiting)
+			break;
+		else if (TargetFrametime - timeElapsed > 2.0) // > 2ms
+			Sleep(1); // Sleep for ~1ms
+		else
+			Sleep(0); // yield thread's time-slice (does not actually sleep)
+	}
+	while (TargetFrametime > timeElapsed);
+
+	FramelimiterPrevTicks = timeCurrent;
+
+	// Not really sure what the second part of IsAliveEvt check is doing
+	// Seems to skip setting timeElapsed to the fixed FramelimiterTargetFrametime at least
+	// Guess that means the true timeElapsed gets passed to the game? (after being limited to 60 like above)
+	if (isAliveEvt_result && gameFramerate != 30)
+	{
+		if (timeElapsed > 33.333333333333333)
+			timeElapsed = 33.333333333333333;
+	}
+	else
+	{
+		// TODO: using the actual time elapsed since last frame instead of FramelimiterTargetFrametime would solve slowdown issues
+		// (similar to https://github.com/nipkownix/re4_tweaks/pull/25)
+		// but it's not known how well the game works with values that aren't 0.5 (60fps) or 1 (30fps)
+		// so for now we'll just work pretty much the same as the game itself, unless UseDynamicFrametime is set
+		if (!pConfig->bUseDynamicFrametime)
+			timeElapsed = TargetFrametime;
+	}
+
+	GlobalPtr()->deltaTime_70 = float((timeElapsed / 1000) * 30.0);
+
+	SetThreadAffinityMask(curThread, prevAffinityMask);
+}
+
 void Init_DisplayTweaks()
 {
+	// Implements new reduced-CPU-usage limiter
+	if (pConfig->bReplaceFramelimiter)
+	{
+		// nop beginning of framelimiter code (sets up thread affinity to core 0)
+		auto pattern = hook::pattern("A3 ? ? ? ? 6A 00 FF 15 ? ? ? ? 50 FF");
+		uint8_t* framelimiterStart = pattern.count(1).get(0).get<uint8_t>(5);
+		pattern = hook::pattern("E8 ? ? ? ? 85 C0 75 ? D9 EE EB ?");
+		uint8_t* framelimiterEnd = pattern.count(1).get(0).get<uint8_t>(0);
+		Nop(framelimiterStart, framelimiterEnd - framelimiterStart); // 6549C3 to 6549D9 (1.1.0)
+
+		pattern = hook::pattern("B9 ? ? ? ? E8 ? ? ? ? 84 C0 74 ? E8 ? ? ? ? 83 F8 1E");
+		framelimiterStart = pattern.count(1).get(0).get<uint8_t>(0xA); // 654A1E
+		pattern = hook::pattern("8D 85 ? ? ? ? 50 FF D3 DF AD ? ? ? ? 8D 8D");
+		framelimiterEnd = pattern.count(1).get(0).get<uint8_t>(0); // 654B0A
+
+		Nop(framelimiterStart, framelimiterEnd - framelimiterStart);
+
+		Patch(framelimiterStart, uint8_t(0x50)); // push eax (pass return value of EventMgr::IsAliveEvt)
+		InjectHook(framelimiterStart + 1, Framelimiter_Hook, PATCH_CALL);
+		Patch(framelimiterStart + 1 + 5, { 0x83, 0xc4, 0x04 }); // add esp, 4 (needed to allow WinMain to exit properly)
+
+		spd::log()->info("Framelimiter replaced");
+	}
+
 	// Fix broken effects
 	Init_FilterXXFixes();
 

dllmain/Game.cpp

@@ -17,6 +17,12 @@ bool GameVersionIsDebug()
 	return gameIsDebugBuild;
 }
 
+uint32_t* ptrGameVariableFrameRate;
+int GameVariableFrameRate()
+{
+	return *(int32_t*)(ptrGameVariableFrameRate);
+}
+
 uint32_t* ptrLastUsedDevice = nullptr;
 InputDevices LastUsedDevice()
 {
@@ -166,6 +172,10 @@ bool Init_Game()
 	con.AddConcatLog("Game version = ", GameVersion().data());
 	#endif
 
+	// Pointer to users variableframerate setting value
+	pattern = hook::pattern("89 0D ? ? ? ? 0F 95 ? 88 15 ? ? ? ? D9 1D ? ? ? ? A3 ? ? ? ? DB 46 ? D9 1D ? ? ? ? 8B 4E ? 89 0D ? ? ? ? 8B 4D ? 5E");
+	ptrGameVariableFrameRate = *pattern.count(1).get(0).get<uint32_t*>(2);
+
 	// LastUsedDevice pointer
 	pattern = hook::pattern("A1 ? ? ? ? 85 C0 74 ? 83 F8 ? 74 ? 81 F9");
 	ptrLastUsedDevice = *pattern.count(1).get(0).get<uint32_t*>(1);

dllmain/Game.h

@@ -24,6 +24,7 @@ extern SND_CTRL* Snd_ctrl_work;
 
 std::string GameVersion();
 bool GameVersionIsDebug();
+int GameVariableFrameRate();
 InputDevices LastUsedDevice();
 bool isController();
 bool isKeyboardMouse();

dllmain/Settings.cpp

@@ -138,13 +138,15 @@ void Config::ReadSettings(std::string_view ini_path)
 	else
 		pConfig->bEnableFOV = false;
 
+	pConfig->bDisableVsync = iniReader.ReadBoolean("DISPLAY", "DisableVsync", pConfig->bDisableVsync);
+
 	pConfig->bUltraWideAspectSupport = iniReader.ReadBoolean("DISPLAY", "UltraWideAspectSupport", pConfig->bUltraWideAspectSupport);
 	pConfig->bSideAlignHUD = iniReader.ReadBoolean("DISPLAY", "SideAlignHUD", pConfig->bSideAlignHUD);
 	pConfig->bStretchFullscreenImages = iniReader.ReadBoolean("DISPLAY", "StretchFullscreenImages", pConfig->bStretchFullscreenImages);
 	pConfig->bStretchVideos = iniReader.ReadBoolean("DISPLAY", "StretchVideos", pConfig->bStretchVideos);
 	pConfig->bRemove16by10BlackBars = iniReader.ReadBoolean("DISPLAY", "Remove16by10BlackBars", pConfig->bRemove16by10BlackBars);
 
-	pConfig->bDisableVsync = iniReader.ReadBoolean("DISPLAY", "DisableVsync", pConfig->bDisableVsync);
+	pConfig->bReplaceFramelimiter = iniReader.ReadBoolean("DISPLAY", "ReplaceFramelimiter", pConfig->bReplaceFramelimiter);
 	pConfig->bFixDPIScale = iniReader.ReadBoolean("DISPLAY", "FixDPIScale", pConfig->bFixDPIScale);
 	pConfig->bFixDisplayMode = iniReader.ReadBoolean("DISPLAY", "FixDisplayMode", pConfig->bFixDisplayMode);
 	pConfig->iCustomRefreshRate = iniReader.ReadInteger("DISPLAY", "CustomRefreshRate", pConfig->iCustomRefreshRate);
@@ -360,6 +362,8 @@ void Config::ReadSettings(std::string_view ini_path)
 	// DEBUG
 	pConfig->bVerboseLog = iniReader.ReadBoolean("DEBUG", "VerboseLog", pConfig->bVerboseLog);
 	pConfig->bNeverHideCursor = iniReader.ReadBoolean("DEBUG", "NeverHideCursor", pConfig->bNeverHideCursor);
+	pConfig->bUseDynamicFrametime = iniReader.ReadBoolean("DEBUG", "UseDynamicFrametime", pConfig->bUseDynamicFrametime);
+	pConfig->bDisableFramelimiting = iniReader.ReadBoolean("DEBUG", "DisableFramelimiting", pConfig->bDisableFramelimiting);
 }
 
 std::mutex settingsThreadRunningMutex;
@@ -406,14 +410,15 @@ DWORD WINAPI WriteSettingsThread(LPVOID lpParameter)
 
 	// DISPLAY
 	iniReader.WriteFloat("DISPLAY", "FOVAdditional", pConfig->fFOVAdditional);
+	iniReader.WriteBoolean("DISPLAY", "DisableVsync", pConfig->bDisableVsync);
 
 	iniReader.WriteBoolean("DISPLAY", "UltraWideAspectSupport", pConfig->bUltraWideAspectSupport);
 	iniReader.WriteBoolean("DISPLAY", "SideAlignHUD", pConfig->bSideAlignHUD);
 	iniReader.WriteBoolean("DISPLAY", "StretchFullscreenImages", pConfig->bStretchFullscreenImages);
 	iniReader.WriteBoolean("DISPLAY", "StretchVideos", pConfig->bStretchVideos);
 	iniReader.WriteBoolean("DISPLAY", "Remove16by10BlackBars", pConfig->bRemove16by10BlackBars);
 
-	iniReader.WriteBoolean("DISPLAY", "DisableVsync", pConfig->bDisableVsync);
+	iniReader.WriteBoolean("DISPLAY", "ReplaceFramelimiter", pConfig->bReplaceFramelimiter);
 	iniReader.WriteBoolean("DISPLAY", "FixDPIScale", pConfig->bFixDPIScale);
 	iniReader.WriteBoolean("DISPLAY", "FixDisplayMode", pConfig->bFixDisplayMode);
 	iniReader.WriteInteger("DISPLAY", "CustomRefreshRate", pConfig->iCustomRefreshRate);
@@ -550,12 +555,13 @@ void Config::LogSettings()
 	// DISPLAY
 	spd::log()->info("+ DISPLAY------------------------+-----------------+");
 	spd::log()->info("| {:<30} | {:>15} |", "FOVAdditional", pConfig->fFOVAdditional);
+	spd::log()->info("| {:<30} | {:>15} |", "DisableVsync", pConfig->bDisableVsync ? "true" : "false");
 	spd::log()->info("| {:<30} | {:>15} |", "UltraWideAspectSupport", pConfig->bUltraWideAspectSupport ? "true" : "false");
 	spd::log()->info("| {:<30} | {:>15} |", "SideAlignHUD", pConfig->bSideAlignHUD ? "true" : "false");
 	spd::log()->info("| {:<30} | {:>15} |", "StretchFullscreenImages", pConfig->bStretchFullscreenImages ? "true" : "false");
 	spd::log()->info("| {:<30} | {:>15} |", "StretchVideos", pConfig->bStretchVideos ? "true" : "false");
 	spd::log()->info("| {:<30} | {:>15} |", "Remove16by10BlackBars", pConfig->bRemove16by10BlackBars ? "true" : "false");
-	spd::log()->info("| {:<30} | {:>15} |", "DisableVsync", pConfig->bDisableVsync ? "true" : "false");
+	spd::log()->info("| {:<30} | {:>15} |", "ReplaceFramelimiter", pConfig->bReplaceFramelimiter ? "true" : "false");
 	spd::log()->info("| {:<30} | {:>15} |", "FixDPIScale", pConfig->bFixDPIScale ? "true" : "false");
 	spd::log()->info("| {:<30} | {:>15} |", "FixDisplayMode", pConfig->bFixDisplayMode ? "true" : "false");
 	spd::log()->info("| {:<30} | {:>15} |", "CustomRefreshRate", pConfig->iCustomRefreshRate);
@@ -698,5 +704,7 @@ void Config::LogSettings()
 	spd::log()->info("+ DEBUG--------------------------+-----------------+");
 	spd::log()->info("| {:<30} | {:>15} |", "VerboseLog", pConfig->bVerboseLog ? "true" : "false");
 	spd::log()->info("| {:<30} | {:>15} |", "NeverHideCursor", pConfig->bNeverHideCursor ? "true" : "false");
+	spd::log()->info("| {:<30} | {:>15} |", "UseDynamicFrametime", pConfig->bUseDynamicFrametime ? "true" : "false");
+	spd::log()->info("| {:<30} | {:>15} |", "DisableFramelimiting", pConfig->bDisableFramelimiting ? "true" : "false");
 	spd::log()->info("+--------------------------------+-----------------+");
 }

dllmain/Settings.h

@@ -10,12 +10,13 @@ class Config
 	// DISPLAY
 	float fFOVAdditional = 0.0f;
 	bool bEnableFOV = false;
+	bool bDisableVsync = false;
 	bool bUltraWideAspectSupport = true;
 	bool bSideAlignHUD = true;
 	bool bStretchFullscreenImages = false;
 	bool bStretchVideos = false;
 	bool bRemove16by10BlackBars = true;
-	bool bDisableVsync = false;
+	bool bReplaceFramelimiter = true;
 	bool bFixDPIScale = true;
 	bool bFixDisplayMode = true;
 	int iCustomRefreshRate = -1;
@@ -131,6 +132,8 @@ class Config
 	// DEBUG
 	bool bVerboseLog = false;
 	bool bNeverHideCursor = false;
+	bool bUseDynamicFrametime = false;
+	bool bDisableFramelimiting = false;
 
 	bool HasUnsavedChanges = false;
 

dllmain/cfgMenu.cpp

@@ -422,6 +422,22 @@ void cfgMenuRender()
 							pConfig->fFOVAdditional = 0.0f;
 					}
 
+					// DisableVsync
+					{
+						ImGui_ColumnSwitch();
+
+						if (ImGui::Checkbox("DisableVsync", &pConfig->bDisableVsync))
+						{
+							pConfig->HasUnsavedChanges = true;
+							NeedsToRestart = true;
+						}
+
+						ImGui_ItemSeparator();
+
+						ImGui::Dummy(ImVec2(10, 10));
+						ImGui::TextWrapped("Force V-Sync to be disabled. For some reason the vanilla game doesn't provide a functional way to do this.");
+					}
+
 					// Aspect ratio tweaks
 					{
 						ImGui_ColumnSwitch();
@@ -463,11 +479,11 @@ void cfgMenuRender()
 						ImGui::TextWrapped("(Change the resolution for this setting to take effect)");
 					}
 
-					// DisableVsync
+					// ReplaceFramelimiter
 					{
 						ImGui_ColumnSwitch();
 
-						if (ImGui::Checkbox("DisableVsync", &pConfig->bDisableVsync))
+						if (ImGui::Checkbox("ReplaceFramelimiter", &pConfig->bReplaceFramelimiter))
 						{
 							pConfig->HasUnsavedChanges = true;
 							NeedsToRestart = true;
@@ -476,7 +492,8 @@ void cfgMenuRender()
 						ImGui_ItemSeparator();
 
 						ImGui::Dummy(ImVec2(10, 10));
-						ImGui::TextWrapped("Force V-Sync to be disabled. For some reason the vanilla game doesn't provide a functional way to do this.");
+						ImGui::TextWrapped("Replaces the games 60/30FPS framelimiter with our own version, which reduces CPU usage quite a lot.");
+						ImGui::TextWrapped("(experimental, not known if the new framelimiter performs the same as the old one yet)");
 					}
 
 					// FixDPIScale

settings/settings_string.h

@@ -4,6 +4,9 @@ const char* defaultSettings = R""""(
 ; Additional FOV value. 20 seems good for most cases.
 FOVAdditional = 0.0
 
+; Force V-Sync to be disabled. For some reason the vanilla game doesn't provide a functional way to do this.
+DisableVsync = false
+
 ; Fixes the incorrect aspect ratio when playing in ultrawide resolutions, 
 ; preventing the image from being cut off and the HUD appearing off-screen.
 UltraWideAspectSupport = true
@@ -21,10 +24,11 @@ StretchVideos = false
 
 ; Removes top and bottom black bars that are present when playing in 16:10.
 ; Will crop a few pixels from each side of the screen.
-Remove16by10BlackBars = false
+Remove16by10BlackBars = true
 
-; Force V-Sync to be disabled. For some reason the vanilla game doesn't provide a functional way to do this.
-DisableVsync = false
+; Replaces the games 60/30FPS framelimiter with our own version, which reduces CPU usage quite a lot.
+; (experimental, not known if the new framelimiter performs the same as the old one yet)
+ReplaceFramelimiter = true
 
 ; Forces game to run at normal 100% DPI scaling, fixes resolution issues for players that have above 100% DPI scaling set.
 FixDPIScale = true
@@ -346,4 +350,14 @@ DisableMenuTip = false
 ; Logs extra information.
 VerboseLog = false
 NeverHideCursor = false
-)"""";
+
+; Passes the actual elapsed frametime to the game instead of a fixed 30/60FPS frametime.
+; Should help reduce slowdown in-game when FPS fails to reach the games framerate setting.
+; (experimental, certain things may act strange when using non-fixed frametime, especially audio)
+UseDynamicFrametime = false
+
+; Disables any kind of framelimiting.
+; Useful for comparing "true" FPS/frametime when making performance-related changes.
+; (requires ReplaceFramelimiter = true, recommend DisableVsync too)
+DisableFramelimiting = false
+)"""";