Clock updates

apps/RenderCadenceCompositor/render/InputFrameTexture.cpp

@@ -71,7 +71,7 @@ GLuint InputFrameTexture::PollAndUpload(InputFrameMailbox* mailbox)
 		return mTexture;
 
 	InputFrame frame;
-	if (!mailbox->TryAcquireLatest(frame))
+	if (!mailbox->TryAcquireOldest(frame))
 	{
 		++mUploadMisses;
 		mLastUploadMilliseconds = 0.0;

apps/RenderCadenceCompositor/render/RenderCadenceClock.cpp

@@ -13,6 +13,7 @@ RenderCadenceClock::RenderCadenceClock(double frameDurationMilliseconds)
 void RenderCadenceClock::Reset(TimePoint now)
 {
 	mNextRenderTime = now;
+	mPendingFrameAdvance = 1;
 	mOverrunCount = 0;
 	mSkippedFrameCount = 0;
 }
@@ -27,10 +28,12 @@ RenderCadenceClock::Tick RenderCadenceClock::Poll(TimePoint now)
 	}
 
 	tick.due = true;
+	mPendingFrameAdvance = 1;
 	const Duration lateBy = now - mNextRenderTime;
 	if (lateBy > mFrameDuration)
 	{
 		tick.skippedFrames = static_cast<uint64_t>(lateBy / mFrameDuration);
+		mPendingFrameAdvance += tick.skippedFrames;
 		++mOverrunCount;
 		mSkippedFrameCount += tick.skippedFrames;
 	}
@@ -39,7 +42,8 @@ RenderCadenceClock::Tick RenderCadenceClock::Poll(TimePoint now)
 
 void RenderCadenceClock::MarkRendered(TimePoint now)
 {
-	mNextRenderTime += mFrameDuration;
+	mNextRenderTime += mFrameDuration * mPendingFrameAdvance;
+	mPendingFrameAdvance = 1;
 	if (now - mNextRenderTime > mFrameDuration * 4)
 		mNextRenderTime = now + mFrameDuration;
 }

apps/RenderCadenceCompositor/render/RenderCadenceClock.h

@@ -31,6 +31,7 @@ public:
 private:
 	Duration mFrameDuration;
 	TimePoint mNextRenderTime = Clock::now();
+	uint64_t mPendingFrameAdvance = 1;
 	uint64_t mOverrunCount = 0;
 	uint64_t mSkippedFrameCount = 0;
 };