Index: source/main.cpp
===================================================================
--- source/main.cpp
+++ source/main.cpp
@@ -126,6 +126,8 @@
 
 #include <chrono>
 
+using namespace std::literals;
+
 extern CStrW g_UniqueLogPostfix;
 
 // Determines the lifetime of the mainloop
@@ -154,8 +156,6 @@
 static int g_ResizedW;
 static int g_ResizedH;
 
-static std::chrono::high_resolution_clock::time_point lastFrameTime;
-
 bool IsQuitRequested()
 {
 	return g_Shutdown == ShutdownType::Quit;
@@ -176,8 +176,10 @@
 	g_Shutdown = ShutdownType::RestartAsAtlas;
 }
 
+namespace
+{
 // main app message handler
-static InReaction MainInputHandler(const SDL_Event_* ev)
+InReaction MainInputHandler(const SDL_Event_* ev)
 {
 	switch(ev->ev.type)
 	{
@@ -251,7 +253,7 @@
 
 
 // dispatch all pending events to the various receivers.
-static void PumpEvents()
+void PumpEvents()
 {
 	ScriptRequest rq(g_GUI->GetScriptInterface());
 
@@ -278,7 +280,7 @@
  * Optionally throttle the render frequency in order to
  * prevent 100% workload of the currently used CPU core.
  */
-inline static void LimitFPS()
+void LimitFPS(const std::chrono::steady_clock::time_point& frameStart)
 {
 	if (g_VideoMode.IsVSyncEnabled())
 		return;
@@ -290,17 +292,12 @@
 	if (fpsLimit < 20.0 || fpsLimit >= 360.0)
 		return;
 
-	double wait = 1000.0 / fpsLimit -
-		std::chrono::duration_cast<std::chrono::microseconds>(
-			std::chrono::high_resolution_clock::now() - lastFrameTime).count() / 1000.0;
+	const auto earliestFrameStop = frameStart + 1.0s / fpsLimit;
 
-	if (wait > 0.0)
-		SDL_Delay(wait);
-
-	lastFrameTime = std::chrono::high_resolution_clock::now();
+	std::this_thread::sleep_until(earliestFrameStop);
 }
 
-static int ProgressiveLoad()
+int ProgressiveLoad()
 {
 	PROFILE3("progressive load");
 
@@ -345,8 +342,7 @@
 	return 0;
 }
 
-
-static void RendererIncrementalLoad()
+void RendererIncrementalLoad()
 {
 	PROFILE3("renderer incremental load");
 
@@ -360,8 +356,9 @@
 	while (more && timer_Time() - startTime < maxTime);
 }
 
-static void Frame(RL::Interface* rlInterface)
+void Frame(RL::Interface* rlInterface)
 {
+	const std::chrono::steady_clock::time_point chronoTime{std::chrono::steady_clock::now()};
 	g_Profiler2.RecordFrameStart();
 	PROFILE2("frame");
 	g_Profiler2.IncrementFrameNumber();
@@ -451,10 +448,10 @@
 
 	g_Profiler.Frame();
 
-	LimitFPS();
+	LimitFPS(chronoTime);
 }
 
-static void NonVisualFrame()
+void NonVisualFrame()
 {
 	g_Profiler2.RecordFrameStart();
 	PROFILE2("frame");
@@ -475,7 +472,7 @@
 		QuitEngine();
 }
 
-static void MainControllerInit()
+void MainControllerInit()
 {
 	// add additional input handlers only needed by this controller:
 
@@ -483,12 +480,12 @@
 	in_add_handler(MainInputHandler);
 }
 
-static void MainControllerShutdown()
+void MainControllerShutdown()
 {
 	in_reset_handlers();
 }
 
-static std::optional<RL::Interface> CreateRLInterface(const CmdLineArgs& args)
+std::optional<RL::Interface> CreateRLInterface(const CmdLineArgs& args)
 {
 	if (!args.Has("rl-interface"))
 		return std::nullopt;
@@ -505,7 +502,7 @@
 
 // moved into a helper function to ensure args is destroyed before
 // exit(), which may result in a memory leak.
-static void RunGameOrAtlas(const PS::span<const char* const> argv)
+void RunGameOrAtlas(const PS::span<const char* const> argv)
 {
 	const CmdLineArgs args(argv);
 
@@ -725,6 +722,7 @@
 	Threading::TaskManager::Instance().ClearQueue();
 	CXeromyces::Terminate();
 }
+} // anonymous namespace
 
 #if OS_ANDROID
 // In Android we compile the engine as a shared library, not an executable,