Prepare for deferred waits

Core/FrameTiming.cpp

@@ -32,6 +32,17 @@
 
 FrameTiming g_frameTiming;
 
+void WaitUntil(double now, double timestamp) {
+#ifdef _WIN32
+	while (time_now_d() < timestamp) {
+		sleep_ms(1); // Sleep for 1ms on this thread
+	}
+#else
+	const double left = timestamp - now;
+	usleep((long)(left * 1000000));
+#endif
+}
+
 inline Draw::PresentMode GetBestImmediateMode(Draw::PresentMode supportedModes) {
 	if (supportedModes & Draw::PresentMode::MAILBOX) {
 		return Draw::PresentMode::MAILBOX;
@@ -50,6 +61,22 @@ void FrameTiming::Reset(Draw::DrawContext *draw) {
 	}
 }
 
+void FrameTiming::DeferWaitUntil(double until, double *curTimePtr) {
+	_dbg_assert_(until > 0.0);
+	waitUntil_ = until;
+	curTimePtr_ = curTimePtr;
+}
+
+void FrameTiming::PostSubmit() {
+	if (waitUntil_ != 0.0) {
+		WaitUntil(time_now_d(), waitUntil_);
+		if (curTimePtr_) {
+			*curTimePtr_ = waitUntil_;
+		}
+		waitUntil_ = 0.0;
+	}
+}
+
 Draw::PresentMode ComputePresentMode(Draw::DrawContext *draw, int *interval) {
 	Draw::PresentMode mode = Draw::PresentMode::FIFO;
 

Core/FrameTiming.h

@@ -8,14 +8,23 @@ namespace Draw {
 class DrawContext;
 }
 
-struct FrameTiming {
+class FrameTiming {
+public:
+	void DeferWaitUntil(double until, double *curTimePtr);
+	void PostSubmit();
+	void Reset(Draw::DrawContext *draw);
+
 	// Some backends won't allow changing this willy nilly.
 	Draw::PresentMode presentMode;
 	int presentInterval;
 
-	void Reset(Draw::DrawContext *draw);
+private:
+	double waitUntil_;
+	double *curTimePtr_;
 };
 
 extern FrameTiming g_frameTiming;
 
 Draw::PresentMode ComputePresentMode(Draw::DrawContext *draw, int *interval);
+
+void WaitUntil(double now, double timestamp);

Core/HLE/sceDisplay.cpp

@@ -440,15 +440,7 @@ static void DoFrameTiming(bool throttle, bool *skipFrame, float scaledTimestep,
 			// Wait until we've caught up.
 			// TODO: This is the wait we actually move to after the frame.
 			// But watch out, curFrameTime below must be updated correctly - I think.
-
-			while (time_now_d() < nextFrameTime) {
-#ifdef _WIN32
-				sleep_ms(1); // Sleep for 1ms on this thread
-#else
-				const double left = nextFrameTime - curFrameTime;
-				usleep((long)(left * 1000000));
-#endif
-			}
+			WaitUntil(curFrameTime, nextFrameTime);
 		}
 		curFrameTime = time_now_d();
 	}

UI/NativeApp.cpp

@@ -1117,6 +1117,7 @@ void NativeFrame(GraphicsContext *graphicsContext) {
 
 	// This, between EndFrame and Present, is where we should actually wait to do present time management.
 	// There might not be a meaningful distinction here for all backends..
+	g_frameTiming.PostSubmit();
 
 	if (renderCounter < 10 && ++renderCounter == 10) {
 		// We're rendering fine, clear out failure info.