Progress on Animation Queue Pipeline

Source/Integration/AnimQueue.h

@@ -2,6 +2,7 @@
 
 #include "CoreMinimal.h"
 #include "StringDecoder.h"
+#include "Containers/Deque.h"
 
 ////////////////////////////////////////////////
 //
@@ -24,12 +25,25 @@ enum EAnimValueType {
 // The body consists of a sequence of FAnimField
 // records.  The body is encoded, to read the
 // FAnimField records you need an FAnimStepDecoder.
+// This comes in two versions: the string version,
+// and the string_view version.
 //
 ////////////////////////////////////////////////
 
 struct FAnimStep {
 	uint32 Hash;
 	std::string_view Body;
+
+	FAnimStep() : Hash(0), Body("") {}
+	FAnimStep(uint32 h, std::string_view b) : Hash(h), Body(b) {}
+};
+
+struct FAnimStoredStep {
+	uint64 Hash;
+	std::string Body;
+
+	FAnimStoredStep() : Hash(0), Body("") {}
+	FAnimStoredStep(uint32 h, std::string_view b) : Hash(h), Body(b) {}
 };
 
 ////////////////////////////////////////////////
@@ -106,6 +120,7 @@ public:
 	// Initialize the FAnimStepDecoder from the FAnimStep.
 	// 
 	FAnimStepDecoder(const FAnimStep &step) : Decoder(step.Body) {}
+	FAnimStepDecoder(const FAnimStoredStep& step) : Decoder(step.Body) {}
 
 	// Return true if the parser has reached the end of the string.
 	//
@@ -119,3 +134,76 @@ public:
 	//
 	static FString DebugString(const FAnimStep &step);
 };
+
+////////////////////////////////////////////////
+//
+// FAnimTracker
+//
+// This class monitors the animation queue for a single
+// tangible.  It can identify when a new animation has
+// appeared on the animation queue, and when animations have
+// been removed from the animation queue.  It also
+// keeps track of which animations have been started.
+// 
+////////////////////////////////////////////////
+
+class FAnimTracker {
+public:
+	// Our own copy of the animation queue.  We only
+	// store the hashes, not the steps.  The First element
+	// of the queue is the oldest item.
+	//
+	TDeque<FAnimStoredStep> AQ;
+
+	// The sequence number of the first item in AQ.
+	//
+	int32 FirstSeqno;
+
+	// Map from hash to sequence number.
+	//
+	TMap<uint64, int32> HashToSeqno;
+
+	// The sequence number of the first unstarted animation.
+	//
+	int32 UnstartedSeqno;
+
+	// Array of recently-aborted hash values.
+	TArray<uint64> AbortedHashes;
+
+public:
+	// Construct a tracker.
+	//
+	// Initially, the tracker is in the empty (Clear) state.
+	//
+	FAnimTracker();
+
+	// Update from the specified animation queue.
+	//
+	// After the update is done, AQ will be a copy
+	// of the animation queue that is passed in.
+	//
+	void Update(std::string_view encqueue);
+
+	// Fetch the aborted hash values.
+	//
+	// This gets the array of aborted hashes and clears
+	// the stored array.
+	//
+	TArray<uint64> GetAborted();
+
+	// Return true if there are any unstarted animation steps.
+	//
+	bool AnyUnstarted();
+
+	// Get the next unstarted animation step.
+	//
+	// You may only call this if AnyUnstarted returns true.
+	//
+	FAnimStoredStep GetUnstarted();
+
+	// Declare that an animation has been started.
+	//
+	// After starting an animation, you should call this.
+	//
+	void Started(uint64 Hash);
+};