pass 2

apps/LoopThroughWithOpenGLCompositing/runtime/RuntimeSnapshotProvider.cpp

@@ -75,11 +75,14 @@ void RuntimeSnapshotProvider::AdvanceFrame()
 	mRuntimeStore.AdvanceFrameCounter();
 }
 
-RuntimeRenderStateSnapshot RuntimeSnapshotProvider::GetRenderStateSnapshot(unsigned outputWidth, unsigned outputHeight) const
+RuntimeRenderStateSnapshot RuntimeSnapshotProvider::PublishRenderStateSnapshot(unsigned outputWidth, unsigned outputHeight) const
 {
 	for (;;)
 	{
 		const RuntimeSnapshotVersions versionsBefore = GetVersions();
+		RuntimeRenderStateSnapshot publishedSnapshot;
+		if (TryGetPublishedRenderStateSnapshot(outputWidth, outputHeight, versionsBefore, publishedSnapshot))
+			return publishedSnapshot;
 
 		RuntimeRenderStateSnapshot snapshot;
 		snapshot.outputWidth = outputWidth;
@@ -91,14 +94,17 @@ RuntimeRenderStateSnapshot RuntimeSnapshotProvider::GetRenderStateSnapshot(unsig
 			versionsBefore.parameterStateVersion == versionsAfter.parameterStateVersion)
 		{
 			snapshot.versions = versionsAfter;
+			StorePublishedRenderStateSnapshot(snapshot);
 			return snapshot;
 		}
 	}
 }
 
-bool RuntimeSnapshotProvider::TryGetRenderStateSnapshot(unsigned outputWidth, unsigned outputHeight, RuntimeRenderStateSnapshot& snapshot) const
+bool RuntimeSnapshotProvider::TryPublishRenderStateSnapshot(unsigned outputWidth, unsigned outputHeight, RuntimeRenderStateSnapshot& snapshot) const
 {
 	const RuntimeSnapshotVersions versionsBefore = GetVersions();
+	if (TryGetPublishedRenderStateSnapshot(outputWidth, outputHeight, versionsBefore, snapshot))
+		return true;
 
 	std::vector<RuntimeRenderState> states;
 	if (!mRuntimeStore.TryBuildLayerRenderStates(outputWidth, outputHeight, states))
@@ -115,10 +121,11 @@ bool RuntimeSnapshotProvider::TryGetRenderStateSnapshot(unsigned outputWidth, un
 	snapshot.outputHeight = outputHeight;
 	snapshot.versions = versionsAfter;
 	snapshot.states = std::move(states);
+	StorePublishedRenderStateSnapshot(snapshot);
 	return true;
 }
 
-bool RuntimeSnapshotProvider::TryRefreshSnapshotParameters(RuntimeRenderStateSnapshot& snapshot) const
+bool RuntimeSnapshotProvider::TryRefreshPublishedSnapshotParameters(RuntimeRenderStateSnapshot& snapshot) const
 {
 	const uint64_t expectedRenderStateVersion = snapshot.versions.renderStateVersion;
 	if (!mRuntimeStore.TryRefreshLayerParameters(snapshot.states))
@@ -129,6 +136,7 @@ bool RuntimeSnapshotProvider::TryRefreshSnapshotParameters(RuntimeRenderStateSna
 		return false;
 
 	snapshot.versions = versions;
+	StorePublishedRenderStateSnapshot(snapshot);
 	return true;
 }
 
@@ -136,3 +144,33 @@ void RuntimeSnapshotProvider::RefreshDynamicRenderStateFields(std::vector<Runtim
 {
 	mRuntimeStore.RefreshDynamicRenderStateFields(states);
 }
+
+bool RuntimeSnapshotProvider::TryGetPublishedRenderStateSnapshot(unsigned outputWidth, unsigned outputHeight,
+	const RuntimeSnapshotVersions& versions, RuntimeRenderStateSnapshot& snapshot) const
+{
+	std::lock_guard<std::mutex> lock(mPublishedSnapshotMutex);
+	if (!mHasPublishedRenderStateSnapshot ||
+		!SnapshotMatches(mPublishedRenderStateSnapshot, outputWidth, outputHeight, versions))
+	{
+		return false;
+	}
+
+	snapshot = mPublishedRenderStateSnapshot;
+	return true;
+}
+
+void RuntimeSnapshotProvider::StorePublishedRenderStateSnapshot(const RuntimeRenderStateSnapshot& snapshot) const
+{
+	std::lock_guard<std::mutex> lock(mPublishedSnapshotMutex);
+	mPublishedRenderStateSnapshot = snapshot;
+	mHasPublishedRenderStateSnapshot = true;
+}
+
+bool RuntimeSnapshotProvider::SnapshotMatches(const RuntimeRenderStateSnapshot& snapshot, unsigned outputWidth, unsigned outputHeight,
+	const RuntimeSnapshotVersions& versions)
+{
+	return snapshot.outputWidth == outputWidth &&
+		snapshot.outputHeight == outputHeight &&
+		snapshot.versions.renderStateVersion == versions.renderStateVersion &&
+		snapshot.versions.parameterStateVersion == versions.parameterStateVersion;
+}