Untested circle buffer implementation

Source/UnrealFightingFramework/Input/FFInputBufferComponent.cpp

@@ -7,16 +7,18 @@ UFFInputBufferComponent::UFFInputBufferComponent()
 	PrimaryComponentTick.bCanEverTick = false;
 }
 
-void UFFInputBufferComponent::Initialize(int32 BufferSize)
-{
-	Buffer.Reserve(BufferSize);
-}
-
 void UFFInputBufferComponent::AddInput(const FFFInputState& InputState)
 {
+	InputBuffer.ForcePush(InputState);
 }
 
 bool UFFInputBufferComponent::CheckInputSequence(const FFFInputSequence& InputSequence)
 {
+    for(int InpIdx = 0; InpIdx < InputBuffer.Num(); InpIdx++)
+    {
+        // read input sequence
+        FFFInputState CurrInput = InputBuffer[InpIdx];
+    }
+
 	return true;
 }

Source/UnrealFightingFramework/Input/FFInputBufferComponent.h

@@ -2,14 +2,27 @@
 
 #pragma once
 
+// FF includes
+#include "Utils/TCircleBuffer.h"
+
 // UE includes
 #include "CoreMinimal.h"
 #include "Components/ActorComponent.h"
-#include "Containers/RingBuffer.h"
 
 #include "FFInputBufferComponent.generated.h"
 
-struct FFFInputState;
+/**
+ *	Struct representing the state of a player's inputs for one frame
+ */
+USTRUCT()
+struct FFFInputState
+{
+    GENERATED_BODY()
+
+	FVector2D	MoveAxes;
+	FVector2D	LookAxes;
+	int32		Buttons;
+};
 
 USTRUCT()
 struct FFFInputSequence
@@ -26,13 +39,11 @@ class UNREALFIGHTINGFRAMEWORK_API UFFInputBufferComponent : public UActorCompone
 public:	
 	UFFInputBufferComponent();
 
-	void Initialize(int32 BufferSize = 120);
-
 	void AddInput(const FFFInputState& InputState);
 
 	bool CheckInputSequence(const FFFInputSequence& InputSequence);
 
 protected:
 	/** The underlying buffer data structure for holding past input states */
-	TRingBuffer<FFFInputState> Buffer;
+	TCircleBuffer<FFFInputState, 120> InputBuffer;
 };

Source/UnrealFightingFramework/Input/FFPlayerController.cpp

@@ -21,7 +21,7 @@ void AFFPlayerController::SendInputsToRemote() const
 
 void AFFPlayerController::FixedTick(float OneFrame)
 {
-    UnacknowledgedInputs.Add(CurrInput);
+    //UnacknowledgedInputs.Push(CurrInput);
     InputBuffer->AddInput(CurrInput);
 
     SendInputsToRemote();

Source/UnrealFightingFramework/Input/FFPlayerController.h

@@ -4,29 +4,16 @@
 
 // FF includes
 #include "FFInputBufferComponent.h"
-#include "UnrealFightingFramework/IFFSystemInterface.h"
+#include "IFFSystemInterface.h"
+#include "Utils/TCircleBuffer.h"
 
 // UE includes
 #include "CoreMinimal.h"
 #include "GameFramework/PlayerController.h"
 #include "InputMappingContext.h"
-#include "Containers/RingBuffer.h"
 
 #include "FFPlayerController.generated.h"
 
-/**
- *	Struct representing the state of a player's inputs for one frame
- */
-USTRUCT()
-struct FFFInputState
-{
-    GENERATED_BODY()
-
-	FVector2D	MoveAxes;
-	FVector2D	LookAxes;
-	int32		Buttons;
-};
-
 /**
  *	A class that collects player inputs, stores them in an input buffer, and sends a rolling window of
  *	unacknowledged inputs to a remote client or server for processing.
@@ -72,5 +59,5 @@ protected:
 	 *	you want the remote machine to re-simulate, where X is the oldest input you want to
 	 *	allow to be re-simulated.
 	 */
-	TRingBuffer<FFFInputState> UnacknowledgedInputs;
+	TCircleBuffer<FFFInputState, 20> UnacknowledgedInputs;
 };

Source/UnrealFightingFramework/UnrealFightingFramework.Build.cs

@@ -1,5 +1,5 @@
 // Unreal Fighting Framework by Kevin Poretti
-
+using System.IO;
 using UnrealBuildTool;
 
 public class UnrealFightingFramework : ModuleRules
@@ -10,14 +10,13 @@ public class UnrealFightingFramework : ModuleRules
 		
 		PublicIncludePaths.AddRange(
 			new string[] {
-				"UnrealFightingFramework"
+				Path.Combine(PluginDirectory,"Source/UnrealFightingFramework"),
 			}
 			);
 				
 		
 		PrivateIncludePaths.AddRange(
 			new string[] {
-				"UnrealFightingFramework"
 			}
 			);
 			

Source/UnrealFightingFramework/Utils/TCircleBuffer.cpp

@@ -1,11 +0,0 @@
-// Unreal Fighting Framework by Kevin Poretti
-
-#include "Utils/TCircleBuffer.h"
-
-TCircleBuffer::TCircleBuffer()
-{
-}
-
-TCircleBuffer::~TCircleBuffer()
-{
-}

Source/UnrealFightingFramework/Utils/TCircleBuffer.h

@@ -5,11 +5,146 @@
 #include "CoreMinimal.h"
 
 /**
+ *	CircleBuffer is a templated array data structure allowing for FIFO, O(1) insertion and removal,
+ *	and wraparound when iterating/accessing elements of the buffer.
  *
+ *	The underlying container type is a statically allocated array. You can use the second
+ *	template parameter to specify the static size of the buffer. Defaults to 64.
  */
+template<typename T, SIZE_T L = 64>
 class UNREALFIGHTINGFRAMEWORK_API TCircleBuffer
 {
 public:
-	TCircleBuffer();
-	~TCircleBuffer();
+	TCircleBuffer()
+	    : WriteIdx(0)
+		, ReadIdx(0)
+	{
+	}
+
+    /**
+     * @brief Adds a new element to the buffer only if there is room.
+     * @param Element to add to the buffer
+     * @return true if there was room in the buffer and the element was added, false otherwise
+     */
+    bool Push(const T& Element)
+    {
+        if(_Num == L)
+        {
+            // buffer full so can't add element
+            return false;
+        }
+        Buffer[WriteIdx] = Element;
+        WriteIdx = (WriteIdx + 1) % L;
+        _Num++;
+        return true;
+    }
+
+    /**
+     * @brief Adds a new element to the buffer.
+     * This function always adds an element. If the buffer is full the oldest element will be overwritten.
+     * @param Element to add to the buffer
+     */
+    void ForcePush(const T& Element)
+	{
+	    if(_Num == L)
+        {
+            // buffer is full so we need to overwrite the oldest element
+            // and make the read index point to the next oldest element
+            ReadIdx = (ReadIdx + 1) % L;
+        }
+        Buffer[WriteIdx] = Element;
+        WriteIdx = (WriteIdx + 1) % L;
+        _Num = FMath::Min(_Num + 1, L);
+	}
+
+    /**
+     * @brief Returns the oldest element in the buffer and removes that element from the buffer.
+     * @param Result out parameter to be filled in with the popped element
+     * @return true if there was an element in the buffer to pop, false otherwise
+     */
+    bool Pop(T* Result)
+    {
+        if(IsEmpty())
+        {
+            return false;
+        }
+
+        *Result = Buffer[ReadIdx];
+        ReadIdx = (ReadIdx + 1) % L;
+        _Num--;
+        return true;
+    }
+
+    /**
+     * @brief Returns the newest element that was added to the buffer
+     * @param Result out parameter to be filled in with the most recently added element
+     * @return true if there was an element in the buffer to peak, false otherwise
+     */
+    bool PeakLast(T* Result)
+    {
+	    if(IsEmpty())
+        {
+            return false;
+        }
+
+        *Result = Buffer[((SSIZE_T)WriteIdx - 1) <= 0 ? L - 1 : (WriteIdx - 1)];
+        return true;
+    }
+
+    /**
+     * @brief Returns the oldest element that was added to the buffer
+     * @param Result out parameter to be filled in with the oldest element
+     * @return true if there was an element in the buffer to peak, false otherwise
+     */
+    bool PeakFirst(T* Result)
+    {
+	    if(IsEmpty())
+        {
+            return false;
+        }
+
+        *Result = Buffer[ReadIdx];
+        return true;
+    }
+
+    /**
+     * @brief Returns the element at an index supplied to the function.
+     * This function will account for write index offset and wraparound of the supplied index.
+     * i.e. Index 0 will be the oldest added element while index Num - 1 will be the newest added element
+     * @param Index of the element to return
+     * @return the element at the index supplied
+     */
+    T& operator[](SIZE_T Index)
+    {
+        return Buffer[((SSIZE_T)WriteIdx - (SSIZE_T)Index) < 0 ? L - (Index - WriteIdx) : WriteIdx - Index];
+    }
+
+    FORCEINLINE bool IsEmpty() const
+	{
+	    return _Num == 0;
+	}
+
+    /**
+     * @brief Returns the max size of the underlying buffer
+     * @return Max size of the underlying buffer
+     */
+    FORCEINLINE SIZE_T Max() const
+	{
+	    return L;
+	}
+
+    /**
+     * @brief Returns the current number of elements of the underlying buffer
+     * @return Max size of the underlying buffer
+     */
+    FORCEINLINE SIZE_T Num() const
+	{
+	    return _Num;
+	}
+
+private:
+    T Buffer[L];
+	SIZE_T WriteIdx;
+	SIZE_T ReadIdx;
+    SIZE_T _Num;
 };