Even more documentation

README.md

@@ -4,8 +4,12 @@ This library provides actors, components, and other general data structures that
 
 ### To-Do
 
-- [ ] State Machine
-- [ ] Input Buffer
+- [X] State Machine
+- [X] Input Buffer
+- [ ] Unit tests
+- [ ] Generic "Actor" class for any game affecting actors that need to run at a fixed tick & rollback
+- [ ] Interfaces/virtual functions for rolling back and resimulating objects
+- [ ] Methods for queueing animations/VFX/SFX when re-simulating
 
 ### Setup
 

Source/UnrealFightingFramework/GameplayFramework/FFAIController.cpp

@@ -0,0 +1,31 @@
+// Project Sword & Gun Copyright Kevin Poretti
+
+
+#include "GameplayFramework/FFAIController.h"
+
+AFFAIController::AFFAIController()
+{
+    InputBuffer = CreateDefaultSubobject<UFFInputBufferComponent>(TEXT("InputBuffer"));
+    bWantsPlayerState = true;
+}
+
+bool AFFAIController::CheckInputSequence(const FFFInputSequence& InInputSequence)
+{
+    return false;
+}
+
+bool AFFAIController::CheckInputSequences(const TArray<FFFInputSequence>& InInputSequences)
+{
+    return false;
+}
+
+FVector AFFAIController::GetMoveInputAsWorldDirection() const
+{
+    return FVector::ZeroVector;
+}
+
+void AFFAIController::DisableMostRecentInput()
+{
+    check(InputBuffer);
+    InputBuffer->DisableMostRecentInput();
+}

Source/UnrealFightingFramework/GameplayFramework/FFAIController.h

@@ -0,0 +1,42 @@
+// Project Sword & Gun Copyright Kevin Poretti
+
+#pragma once
+
+// FF includes
+#include "State/IFFStateOwnerInterface.h"
+#include "Input/FFInputBufferComponent.h"
+
+// UE includes
+#include "CoreMinimal.h"
+#include "AIController.h"
+
+#include "FFAIController.generated.h"
+
+/**
+ * 
+ */
+UCLASS()
+class UNREALFIGHTINGFRAMEWORK_API AFFAIController : public AAIController, public IFFStateOwnerInterface
+{
+	GENERATED_BODY()
+
+public:
+    AFFAIController();
+
+    // IFFStateOwnerInterface
+    UFUNCTION(BlueprintCallable, Category="UFF State Owner Interface")
+    virtual bool CheckInputSequence(const FFFInputSequence& InInputSequence) override;
+
+    UFUNCTION(BlueprintCallable, Category="UFF State Owner Interface")
+    virtual bool CheckInputSequences(const TArray<FFFInputSequence>& InInputSequences) override;
+
+    virtual FVector GetMoveInputAsWorldDirection() const override;
+
+    virtual void DisableMostRecentInput() override;
+    // End of IFFStateOwnerInterface
+
+protected:
+	/** Input Buffer component */
+	UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category = "UFF|Input", meta = (AllowPrivateAccess = "true"))
+	UFFInputBufferComponent* InputBuffer;
+};

Source/UnrealFightingFramework/GameplayFramework/FFGameState.cpp

@@ -1,7 +1,13 @@
-// Project Sword & Gun Copyright Kevin Poretti
+// Unreal Fighting Framework by Kevin Poretti
 
 #include "GameplayFramework/FFGameState.h"
 
+// FF includes
+#include "Input/FFPlayerController.h"
+
+// UE includes
+#include "Kismet/GameplayStatics.h"
+
 void AFFGameState::OnFixedTick(float OneTick)
 {
 }
@@ -11,15 +17,50 @@ void AFFGameState::Tick(float DeltaSeconds)
 {
     Super::Tick(DeltaSeconds);
 
+    /*
+     * TODO: I want to reinvestigate how we're collecting and applying inputs. I seem to keep getting
+     * weird timing issues due to how Unreal collects and informs the game of inputs through function
+     * callbacks rather than some mechanism where we can poll the state of various actions/axes when
+     * it comes time to update. The investigation should be two-fold:
+     *
+     * 1 - is there any alternative ways of using the EnhancedInputComponent but polling for inputs
+     * rather than this whole callback system, so when it is time to tick the game state we can just
+     * do something like a bool bIsJumpPressed = GetActionValue("Jump") for all inputs and axes
+     * we need to collect?
+     *
+     * 2 - if there isn't any polling mechanism in the EnhancedInputComponent, how can we work around
+     * that and what are some of the things we have to keep in mind? What happens when the Unreal tick
+     * rate is slower than the game tick rate? Do we just apply the current input to multiple game ticks?
+     * What about when Unreal's tick rate is faster than the game? Would that make the game feel
+     * unresponsive i.e. feel like inputs are getting dropped?
+     *
+     * 3 - would like to know more about EnhancedInputComponent and inputs in Unreal in general as well.
+     * Are inputs collected in a separate thread? How does unreal determine when to call any input callbacks
+     * you've registered with the input component?
+     */
+
+    // Get inputs
+    AFFPlayerController* PC = Cast<AFFPlayerController>(UGameplayStatics::GetPlayerController(GetWorld(), 0));
+    if(!PC)
+    {
+        UE_LOG(LogTemp, Warning, TEXT("Could not get a local player controller so no inputs could be collected"));
+        return;
+    }
+
+    PC->ModifyRawInput();
+
     // Run anything game logic related at a fixed tick rate
     // TODO: Interpolate between prev and current game state if there is time left in accumulator
     AccumulatedTime += DeltaSeconds;
     while(AccumulatedTime > ONE_TICK)
     {
+        PC->AddCurrentInputToBuffer();
         OnFixedTick(ONE_TICK);
 
         AccumulatedTime -= ONE_TICK;
 
         CurrentTick++;
     }
+
+    PC->ConsumeMoveInput();
 }

Source/UnrealFightingFramework/GameplayFramework/FFGameState.h

@@ -1,4 +1,4 @@
-// Project Sword & Gun Copyright Kevin Poretti
+// Unreal Fighting Framework by Kevin Poretti
 
 #pragma once
 

Source/UnrealFightingFramework/Input/FFInputBufferComponent.cpp

@@ -18,29 +18,37 @@ bool UFFInputBufferComponent::CheckInputSequence(const FFFInputSequence& InputSe
 {
     if(InputSequence.Sequence.IsEmpty())
     {
-        UE_LOG(LogTemp, Error, 
+        UE_LOG(LogTemp, Warning, 
             TEXT("FFInputBufferComponent :: CheckInputSequence - tried to check input sequence but it was empty"));
         return false;
     }
 
     int CondIdx = InputSequence.Sequence.Num() - 1;
     int ElapsedFrames = 0;
-    for(int InpIdx = InputBuffer.Num() - 1; InpIdx > 1; InpIdx--)
+    for(int InpIdx = InputBuffer.Num() - 1; InpIdx > 0; InpIdx--)
     {
         int32 RequiredButtons = InputSequence.Sequence[CondIdx].RequiredButtons;
         EFFButtonState RequiredButtonState = InputSequence.Sequence[CondIdx].RequiredButtonState;
+        int32 TimeoutDuration = InputSequence.Sequence[CondIdx].TimeoutDuration;
         int32 PrevInput = InputBuffer[InpIdx - 1].Buttons;
         int32 CurrInput = InputBuffer[InpIdx].Buttons;
         int32 PrevDisable = InputBuffer[InpIdx - 1].DisabledButtons;
         int32 CurrDisable = InputBuffer[InpIdx].DisabledButtons;
+        bool bCondFoundThisIteration = false;
         switch (RequiredButtonState)
         {
             // TODO: should it be (PrevInput & RequiredButtons) == RequiredButtons or what we have now?
+            // TODO: If you have a sequence that is defined as something like button 1 pressed + button 2 pressed
+            // and the buttons are pressed on the same exact frame, then this implementation will not
+            // account for that. We should keep checking the sequences against the current frame's
+            // inputs until no sequences are detected, then continue on checking through the input buffer.
             case EFFButtonState::BTNS_Pressed:
                 if(!(PrevInput & RequiredButtons | PrevDisable) && 
                    CurrInput & RequiredButtons & ~CurrDisable)
                 {
                     CondIdx--;
+                    ElapsedFrames = 0;
+                    bCondFoundThisIteration = true;
                 }
                 break;
             case EFFButtonState::BTNS_Released:
@@ -48,12 +56,16 @@ bool UFFInputBufferComponent::CheckInputSequence(const FFFInputSequence& InputSe
                    !(CurrInput & RequiredButtons | CurrDisable))
                 {
                     CondIdx--;
+                    ElapsedFrames = 0;
+                    bCondFoundThisIteration = true;
                 }
                 break;
             case EFFButtonState::BTNS_Down:
                 if(CurrInput & RequiredButtons & ~CurrDisable)
                 {
                     CondIdx--;
+                    ElapsedFrames = 0;
+                    bCondFoundThisIteration = true;
                 }
                 break;
             // TODO: implement button held condition
@@ -69,10 +81,14 @@ bool UFFInputBufferComponent::CheckInputSequence(const FFFInputSequence& InputSe
             return true;
         }
 
-        ElapsedFrames++;
-        if(ElapsedFrames > InputSequence.MaxDuration)
+        // No condition found this iteration, so increment elapse frames and see if current condition timed out
+        if(!bCondFoundThisIteration)
         {
-            return false;
+            ElapsedFrames++;
+            if(ElapsedFrames > TimeoutDuration)
+            {
+                return false;
+            }
         }
     }
 
@@ -81,6 +97,16 @@ bool UFFInputBufferComponent::CheckInputSequence(const FFFInputSequence& InputSe
 
 void UFFInputBufferComponent::DisableMostRecentInput()
 {
+    if(InputBuffer.Num() < 2)
+    {
+        return;
+    }
+    
     InputBuffer[InputBuffer.Num() - 1].DisabledButtons |= InputBuffer[InputBuffer.Num() - 1].Buttons;
     InputBuffer[InputBuffer.Num() - 2].DisabledButtons |= InputBuffer[InputBuffer.Num() - 2].Buttons;
 }
+
+void UFFInputBufferComponent::FlushBuffer()
+{
+    InputBuffer.Flush();
+}

Source/UnrealFightingFramework/Input/FFInputBufferComponent.h

@@ -16,7 +16,8 @@ enum class EFFButtonState : uint8
 {
     BTNS_Pressed		UMETA(DisplayName="Pressed"),
 	BTNS_Released		UMETA(DisplayName="Released"),
-    BTNS_Down			UMETA(DisplayName="Down"),    
+    BTNS_Down			UMETA(DisplayName="Down"),
+	//BTNS_Up			UMETA(DisplayName="Up),
 	//BTNS_Held			UMETA(DisplayName="Held"),
 	BTNS_MAX			UMETA(Hidden)
 };
@@ -30,7 +31,7 @@ struct FFFInputState
     GENERATED_BODY()
 
 	FVector2D	MoveAxes;
-	FVector2D	LookAxes;
+	FRotator	LookRot;
 
 	UPROPERTY(EditAnywhere, Meta = (Bitmask))
 	int32		Buttons;
@@ -38,7 +39,7 @@ struct FFFInputState
 
 	FFFInputState()
 	    : MoveAxes(FVector2D::ZeroVector)
-	    , LookAxes(FVector2D::ZeroVector)
+	    , LookRot(FRotator::ZeroRotator)
 	    , Buttons(0)
 	    , DisabledButtons(0)
 	{
@@ -50,17 +51,25 @@ struct FFFInputCondition
 {
     GENERATED_BODY()
 
-	// Buttons required for this specific condition to be valid
+	/** Buttons required for this specific condition to be valid */
 	UPROPERTY(EditAnywhere, BlueprintReadWrite)
 	int32 RequiredButtons;
 
-	// The button state required for condition to be valid i.e. pressed or released
+	/** The button state required for condition to be valid i.e. pressed or released */
 	UPROPERTY(EditAnywhere, BlueprintReadWrite)
 	EFFButtonState RequiredButtonState;
 
+	/*
+	 *	How many ticks that can be checked since the last valid input condition was found before
+	 *	this condition is considered not valid/found in the input buffer
+	 */
+	UPROPERTY(EditAnywhere, BlueprintReadWrite)
+	int32 TimeoutDuration;
+	
 	FFFInputCondition()
         : RequiredButtons(0)
         , RequiredButtonState(EFFButtonState::BTNS_Pressed)
+		, TimeoutDuration(0)
 	{
 	}
 };
@@ -72,12 +81,8 @@ struct FFFInputSequence
 
     UPROPERTY(EditAnywhere, BlueprintReadWrite)
 	TArray<FFFInputCondition> Sequence;
-
-	UPROPERTY(EditAnywhere, BlueprintReadWrite)
-	int32 MaxDuration;
-
+	
 	FFFInputSequence()
-	    : MaxDuration(0)
     {
 	}
 };
@@ -96,6 +101,8 @@ public:
 
 	void DisableMostRecentInput();
 
+	void FlushBuffer();
+	
 protected:
 	/** The underlying buffer data structure for holding past input states */
 	TCircleBuffer<FFFInputState, 120> InputBuffer;

Source/UnrealFightingFramework/Input/FFPlayerController.cpp

@@ -7,6 +7,7 @@
 
 // UE includes
 #include "EnhancedInputSubsystems.h"
+#include "Kismet/KismetMathLibrary.h"
 
 AFFPlayerController::AFFPlayerController()
 {
@@ -25,13 +26,37 @@ void AFFPlayerController::ModifyRawInput()
 }
 
 
-void AFFPlayerController::FixedTick(float OneFrame)
+bool AFFPlayerController::HasMoveInput()
+{
+    // TODO: configurable deadzone
+    return !ModifiedInput.MoveAxes.IsNearlyZero();
+}
+
+
+void AFFPlayerController::ConsumeMoveInput()
+{
+    RawInput.MoveAxes = FVector2D::ZeroVector;
+}
+
+
+FVector AFFPlayerController::GetMoveInputAsWorldDirection() const
+{
+	FRotator ViewRotationYaw = FRotator(0.0f, ModifiedInput.LookRot.Yaw, 0.0f);
+	FVector ForwardInput = UKismetMathLibrary::GetForwardVector(ViewRotationYaw) * ModifiedInput.MoveAxes.Y;
+	FVector RightInput = UKismetMathLibrary::GetRightVector(ViewRotationYaw) * ModifiedInput.MoveAxes.X;
+
+	return ForwardInput + RightInput;
+}
+
+
+void AFFPlayerController::AddCurrentInputToBuffer()
 {
     //UnacknowledgedInputs.Push(RawInput);
     InputBuffer->AddInput(ModifiedInput);
     //SendInputsToRemote();
 }
 
+
 bool AFFPlayerController::CheckInputSequence(const FFFInputSequence& InInputSequence)
 {
     return InputBuffer->CheckInputSequence(InInputSequence);
@@ -56,6 +81,7 @@ bool AFFPlayerController::CheckInputSequences(const TArray<FFFInputSequence>& In
     return false;
 }
 
+
 void AFFPlayerController::DisableMostRecentInput()
 {
     InputBuffer->DisableMostRecentInput();
@@ -77,3 +103,12 @@ void AFFPlayerController::SetupInputComponent()
         }
     }
 }
+
+
+void AFFPlayerController::FlushPressedKeys()
+{
+    Super::FlushPressedKeys();
+
+    RawInput.Buttons = 0;
+    RawInput.MoveAxes = FVector2D::ZeroVector;
+}

Source/UnrealFightingFramework/Input/FFPlayerController.h

@@ -20,7 +20,7 @@
  *	unacknowledged inputs to a remote client or server for processing.
  */
 UCLASS()
-class UNREALFIGHTINGFRAMEWORK_API AFFPlayerController : public APlayerController, public IFFSystemInterface, public IFFStateOwnerInterface
+class UNREALFIGHTINGFRAMEWORK_API AFFPlayerController : public APlayerController, public IFFStateOwnerInterface
 {
 	GENERATED_BODY()
 
@@ -36,7 +36,7 @@ public:
      * @brief Gets the current input after cleaning/modifying the raw input state
      * @return the current input
      */
-    virtual FFFInputState GetModifiedInput() const { return ModifiedInput; };
+    virtual FFFInputState GetModifiedInput() const { return ModifiedInput; }
 
     /**
      * @brief Function called before inputs are passed to the game logic to update the game state.
@@ -47,22 +47,40 @@ public:
      */
     virtual void ModifyRawInput();
 
-	// IFFSystemInterface interface
-	virtual void FixedTick(float OneFrame) override;
-	// End of IFFSystemInterface
+    /**
+     * @brief Checks if the current input state has movement input being applied
+     * @return True if move axes is non-zero, false otherwise
+     */
+	UFUNCTION(BlueprintPure)
+    bool HasMoveInput();
 
-	// IFFStateOwnerInterface
+	/**
+	 * @brief Zeroes out the raw movement axes after input has been processed 
+	 */ 
+	void ConsumeMoveInput();
+
+	/**
+	 * @brief Adds the current state of the player input to the input buffer for processing and
+	 * interpretation after input has been cleaned
+	 */
+    void AddCurrentInputToBuffer();
+
+    // IFFStateOwnerInterface
 	UFUNCTION()
 	virtual bool CheckInputSequence(const FFFInputSequence& InInputSequence) override;
 
 	UFUNCTION()
     virtual bool CheckInputSequences(const TArray<FFFInputSequence>& InputSequences) override;
 
+	virtual FVector GetMoveInputAsWorldDirection() const override;
+
 	virtual void DisableMostRecentInput() override;
 	// End of IFFStateOwnerInterface
 
 	// APlayerController interface
 	virtual void SetupInputComponent() override;
+
+	virtual void FlushPressedKeys() override;
 	// End of APlayerController interface
 
 protected:

Source/UnrealFightingFramework/State/FFState.cpp

@@ -57,13 +57,22 @@ bool UFFState::CanTransition(const FFFStateContext& InStateContext)
         return false;
     }
 
-    return OnCanTransition(InStateContext);
+    return OnCanTransition(InStateContext) && !bIsFollowupState;
 }
 
 
 void UFFState::Enter(const FFFStateContext& InStateContext)
 {
     PlayMontage(InStateContext);
+
+    if(bDisableMostRecentInputOnEntry)
+    {
+        IFFStateOwnerInterface* PC = Cast<IFFStateOwnerInterface>(InStateContext.Owner);
+        if(PC)
+        {
+            PC->DisableMostRecentInput();
+        }
+    }
     
     OnEnter(InStateContext);
 }
@@ -71,8 +80,6 @@ void UFFState::Enter(const FFFStateContext& InStateContext)
 
 void UFFState::Exit(const FFFStateContext& InStateContext, EFFStateFinishReason StateFinishReason)
 {
-    
-    
     if(InStateContext.Avatar && 
       (bStopMontageOnStateEnd && StateFinishReason == EFFStateFinishReason::SFT_DurationMetOrExceeded || StateFinishReason == EFFStateFinishReason::SFT_Interrupted) || 
       (bStopMontageOnMovementModeChange && StateFinishReason == EFFStateFinishReason::SFT_NotInReqMovementMode))
@@ -133,28 +140,24 @@ void UFFState::MovementModeChanged(EMovementMode PrevMovementMode, uint8 Previou
 {
     OnMovementModeChanged(PrevMovementMode, PreviousCustomMode, 
         NewMovementMode, NewCustomMode, InStateContext);
-
-    // TODO: Movement mode MOVE_None means movement is disabled but in this context it means no movement
-    // mode is specifically required to stay in this state i.e. changing from falling to walking
-    // will not exit out of this state. I think I want to use my own movement mode enum just so I
-    // can explicitly document this is what is meant by none
-    if((ReqMovementMode != EMovementMode::MOVE_None && NewMovementMode != ReqMovementMode) || 
-      ((ReqMovementMode == MOVE_Custom) && NewCustomMode != RequiredCustomMode))
-    {
-        Finish(InStateContext, EFFStateFinishReason::SFT_NotInReqMovementMode);
-    }
 }
 
 
-void UFFState::Hit(const FFFStateContext& InStateContext)
+void UFFState::AttackHit(const FHitResult& HitResult, const FFFStateContext& InStateContext)
 {
-    OnHit(InStateContext);
+    OnAttackHit(HitResult, InStateContext);
 }
 
 
-void UFFState::Block(const FFFStateContext& InStateContext)
+void UFFState::HitTaken(const FFFStateContext& InStateContext)
 {
-    OnBlock(InStateContext);
+    OnHitTaken(InStateContext);
+}
+
+
+void UFFState::BlockTaken(const FFFStateContext& InStateContext)
+{
+    OnBlockTaken(InStateContext);
 }
 
 
@@ -166,18 +169,24 @@ void UFFState::Finish(const FFFStateContext& InStateContext, EFFStateFinishReaso
     // the appropriate flags are set. I think having this state finish reason is good but I may want
     // to rethink the way we handle logic for ending a state and which class is in charge of handling
     // what
-    InStateContext.Parent->GoToEntryState(StateFinishReason);
+    
+    if(GetFollowupState(InStateContext) != NAME_None)
+    {
+        InStateContext.Parent->GoToState(GetFollowupState(InStateContext), StateFinishReason);
+    }
+    else
+    {
+        InStateContext.Parent->GoToEntryState(StateFinishReason);
+    }
 }
 
 
-void UFFState::RegisterInputHandler(const FFFInputSequence& InRequiredSequence, FFFInputEventDelegate InDelegate)
+FName UFFState::GetFollowupState_Implementation(const FFFStateContext& InStateContext)
 {
-    FFFInputEventHandler TempHandler;
-    TempHandler.RequiredSequence = InRequiredSequence;
-    TempHandler.Delegate = InDelegate;
-    InputHandlers.Add(TempHandler);
+    return FollowupState;
 }
 
+
 void UFFState::PlayMontage(const FFFStateContext& InStateContext)
 {
     // TODO: think of a better way to handle optionally playing montages other than the one set as MontageToPlay

Source/UnrealFightingFramework/State/FFState.h

@@ -35,6 +35,11 @@ struct FFFStateContext
 
 DECLARE_DYNAMIC_DELEGATE_OneParam(FFFInputEventDelegate, const FFFStateContext&, InStateContext);
 
+/*
+ * TODO: check if this is even used anymore and if not delete? I recall using this in a few
+ * states/actions but it was a pain to use and I switched to checking an input sequence directly in
+ * a state's update function
+ */
 USTRUCT(BlueprintType)
 struct FFFInputEventHandler
 {
@@ -52,10 +57,15 @@ struct FFFInputEventHandler
 UENUM(BlueprintType)
 enum class EFFStateFinishReason : uint8
 {
-    // TODO: document
+	/** State ended due to another state's entry condition being satisfied  */
 	SFT_Interrupted				UMETA(DisplayName="Interrupted"),
+
+	/** State ended because the number of ticks in this state exceeded state's duration property */
     SFT_DurationMetOrExceeded			UMETA(DisplayName="Duration Reached"),
+	
+	/** State ended because the owner is no longer in the movement mode required by the state */
     SFT_NotInReqMovementMode	UMETA(DisplayName="Not In Required Movement Mode"),
+    
 	SFT_MAX						UMETA(Hidden)
 };
 
@@ -112,6 +122,13 @@ public:
     UPROPERTY(EditDefaultsOnly, BlueprintReadOnly, Category="UFF State Properties")
 	TArray<FFFInputSequence> InputSequences;
 
+	/**
+	 *	Should the most recent input in the controlling player's input buffer be disabled when
+	 *	entering this state?
+	 */
+	UPROPERTY(EditDefaultsOnly, BlueprintReadOnly, Category="UFF State Properties")
+	bool bDisableMostRecentInputOnEntry = true;
+	
 	/**
 	 *	If true the state can transition from itself into itself without having to go through
 	 *	another state like Idle
@@ -119,12 +136,24 @@ public:
     UPROPERTY(EditDefaultsOnly, BlueprintReadOnly, Category="UFF State Properties")
 	bool bCanTransitionToSelf = false;
 
+	/**
+	 *	Specifies whether a state is a followup state or not.
+	 *
+	 *	Followup states are states that should only be transitioned into from another specific state
+	 *	but otherwise have no other specific conditions that need to be met to transition.
+	 *	Setting this flag to true when there are no other conditions prevents this state from
+	 *	constantly being transitioned into by the state machine.
+	 */
 	UPROPERTY(EditDefaultsOnly, BlueprintReadOnly, Category="UFF State Properties")
-    TEnumAsByte<EMovementMode> ReqMovementMode;
-
+	bool bIsFollowupState = false;
+	
+	/**
+	 *	State to transition to when this state is finished. If left blank then the entry state
+	 *	of the state machine will be transitioned into.
+	 */
 	UPROPERTY(EditDefaultsOnly, BlueprintReadOnly, Category="UFF State Properties")
-    uint8 RequiredCustomMode;
-
+	FName FollowupState = NAME_None;
+	
 	/**
 	 *	Animation to begin playing when this state is entered
 	 */
@@ -168,7 +197,7 @@ public:
 	 *
 	 *	Calls appropriate Blueprint hooks.
 	 *
-	 *	TODO: document StateFinishReason
+	 *	@param StateFinishReason the reason the state is ending i.e. the state's duration elapse
 	 */
 	virtual void Exit(const FFFStateContext& InStateContext, EFFStateFinishReason StateFinishReason);
 
@@ -181,20 +210,40 @@ public:
 	 */
     virtual void Update(float OneFrame, const FFFStateContext& InStateContext);
 
-	// TODO: document
+	/**
+	 *	Called whenever state owners lands on a walkable surface after they were previously falling.
+	 *
+	 *	Calls appropriate Blueprint hooks.
+	 *
+	 *	@param Hit Hit result for the surface that was landed on
+	 */
 	virtual void Landed(const FHitResult& Hit, const FFFStateContext& InStateContext);
 
-	// TODO: document
+	/**
+	 *	@brief Called whenever the state's owner current movement mode changes
+	 *
+	 *	Calls appropriate Blueprint hooks.
+	 *
+	 *	@param PrevMovementMode previous movement mode.
+	 *	@param PreviousCustomMode previous movement mode if PrevMovementMode is MOVE_Custom
+	 *	@param NewMovementMode new movement mode
+	 *	@param NewCustomMode new movement mode if NewMovementMode is MOVE_Custom
+	 */ 
 	virtual void MovementModeChanged(EMovementMode PrevMovementMode, uint8 PreviousCustomMode, 
 	    EMovementMode NewMovementMode, uint8 NewCustomMode, const FFFStateContext& InStateContext);
 
 	// TODO: document
+	virtual void AttackHit(const FHitResult& HitResult, const FFFStateContext& InStateContext);
+	
+	// TODO: document
+	// TODO: call this callback when the avatar is hit
 	// TODO: pass in hitdata struct as well
-    virtual void Hit(const FFFStateContext& InStateContext);
+    virtual void HitTaken(/*const FHitParams& HitParams,*/ const FFFStateContext& InStateContext);
 
 	// TODO: document
+	// TODO: call this callback when the avatar blocks a hit
 	// TODO: pass in hitdata struct as well
-	virtual void Block(const FFFStateContext& InStateContext);
+	virtual void BlockTaken(const FFFStateContext& InStateContext);
 
     /**
 	 *	Called when you want to exit from this state but no eligible transitions exist to other states,
@@ -211,13 +260,8 @@ public:
      */
     UFUNCTION(BlueprintCallable)
 	virtual void Finish(const FFFStateContext& InStateContext, EFFStateFinishReason StateFinishReason);
-
-	// TODO: document
-	UFUNCTION(BlueprintCallable)
-	virtual void RegisterInputHandler(
-	    const FFFInputSequence& InRequiredSequence, FFFInputEventDelegate InDelegate);
-
-	// TODO: document
+	
+	/** @brief Blueprint hook for when the state is first created. */
 	UFUNCTION(BlueprintNativeEvent, Category="UFF|State|Events")
 	void OnInit(const FFFStateContext& InStateContext);
 
@@ -247,21 +291,47 @@ public:
 	UFUNCTION(BlueprintImplementableEvent, Category="UFF|State|Events")
 	void OnUpdate(float OneFrame, const FFFStateContext& InStateContext);
 
+	/**
+	 *	Returns the next state to transition into when this state finishes.
+	 *
+	 *	This is called during the Finish function, either when the state duration is reached or the
+	 *	state is manually finished due to some other logic.
+	 *
+	 *	By default this returns the name of the state specified by the FollowupState property or
+	 *	NAME_None if the FollowupState is not specified.
+	 */
+	UFUNCTION(BlueprintNativeEvent, Category="UFF|State|Events")
+	FName GetFollowupState(const FFFStateContext& InStateContext);
+	
+	// TODO: Don't like this at all and needs to be refactored or redesigned
 	UFUNCTION(BlueprintCallable, Category="UFF|State|Animations")
 	void PlayMontage(const FFFStateContext& InStateContext);
 
+	// TODO: Don't like this at all and needs to be refactored or redesigned
     /**
      *	Blueprint hook for overriding the logic for when a anim montage plays at the start of a state
      *	@param InStateContext 
      */
     UFUNCTION(BlueprintNativeEvent, Category="UFF|State|Events")
 	void OnPlayMontage(const FFFStateContext& InStateContext);
-
-	// TODO: document
+	
+	/**
+	 *	@brief Blueprint hook for whenever state owners lands on a walkable surface after they were
+	 *	previously falling.
+	 *	
+	 *	@param Hit Hit result for the surface that was landed on
+	 */
 	UFUNCTION(BlueprintImplementableEvent, Category="UFF|State|Events")
 	void OnLanded(const FHitResult& Hit, const FFFStateContext& InStateContext);
 
-	// TODO: document
+	/**
+	 *	@brief Blueprint hook whenever the state's owner current movement mode changes
+	 *	
+	 *	@param PrevMovementMode previous movement mode.
+	 *	@param PreviousCustomMode previous movement mode if PrevMovementMode is MOVE_Custom
+	 *	@param NewMovementMode new movement mode
+	 *	@param NewCustomMode new movement mode if NewMovementMode is MOVE_Custom
+	 */
 	UFUNCTION(BlueprintImplementableEvent, Category="UFF|State|Events")
 	void OnMovementModeChanged(EMovementMode PrevMovementMode, uint8 PreviousCustomMode, 
 	    EMovementMode NewMovementMode, uint8 NewCustomMode, const FFFStateContext& InStateContext);
@@ -269,12 +339,16 @@ public:
 	// TODO: document
     // TODO: pass in hitdata struct as well
     UFUNCTION(BlueprintImplementableEvent, Category="UFF|State|Events")
-	void OnHit(const FFFStateContext& InStateContext);
+	void OnAttackHit(const FHitResult& Hit, const FFFStateContext& InStateContext);
 
+	// TODO: document
+	UFUNCTION(BlueprintImplementableEvent, Category="UFF|State|Events")
+	void OnHitTaken(/*const FHitParams,*/ const FFFStateContext& InStateContext);
+	
 	// TODO: document
     // TODO: pass in hitdata struct as well
     UFUNCTION(BlueprintImplementableEvent, Category="UFF|State|Events")
-	void OnBlock(const FFFStateContext& InStateContext);
+	void OnBlockTaken(/*const FHitParams,*/ const FFFStateContext& InStateContext);
 
 	// UObject interface
 	virtual UWorld* GetWorld() const override;

Source/UnrealFightingFramework/State/FFStateMachineComponent.cpp

@@ -102,21 +102,10 @@ void UFFStateMachineComponent::GoToState(UFFState* NewState, EFFStateFinishReaso
 {
     check(CurrentState);
     check(NewState);
-
-    // if state being transitioned into requires an input sequence we need to disable the most
-    // recent input in the player controller input buffer to prevent unwanted "double firing" of
-    // actions that have short durations but very lenient required input sequences
-    if(NewState->InputSequences.Num() > 0)
-    {
-        IFFStateOwnerInterface* PC = Cast<IFFStateOwnerInterface>(Owner);
-        if(PC)
-        {
-            PC->DisableMostRecentInput();
-        }
-    }
-
+    
     CurrentState->Exit(GetCurrentStateContext(), StateFinishReason);
     TicksInState = 0;
+    OnLandedTick = 0;
     TickStateWasEntered = GetWorld()->GetGameState<AFFGameState>()->GetCurrentTick();
     CurrentSubStateLabel = NAME_None;
     NewState->Enter(GetCurrentStateContext());
@@ -161,6 +150,8 @@ void UFFStateMachineComponent::Landed(const FHitResult& Hit)
 {
     check(CurrentState)
 
+    OnLandedTick = GetWorld()->GetGameState<AFFGameState>()->GetCurrentTick();
+
     CurrentState->Landed(Hit, GetCurrentStateContext());
 }
 
@@ -183,6 +174,16 @@ void UFFStateMachineComponent::MovementModeChanged(EMovementMode PrevMovementMod
         NewMovementMode, NewCustomMode, GetCurrentStateContext());
 }
 
+void UFFStateMachineComponent::AttackHit(const FHitResult& HitResult)
+{
+    check(CurrentState)
+    CurrentState->AttackHit(HitResult, GetCurrentStateContext());
+}
+
+void UFFStateMachineComponent::TakeHit()
+{
+    CurrentState->HitTaken(GetCurrentStateContext());
+}
 
 void UFFStateMachineComponent::FixedTick(float OneFrame)
 {
@@ -233,7 +234,7 @@ UFFState* UFFStateMachineComponent::FindStateWithName(FName StateName)
         }
     }
 
-	UE_LOG(LogTemp, Warning,
+	UE_LOG(LogTemp, Error,
 			TEXT("Could not find state in state machine with name %s"), *StateName.ToString());
 
 	return nullptr;

Source/UnrealFightingFramework/State/FFStateMachineComponent.h

@@ -73,8 +73,10 @@ public:
 	 *
 	 *	Triggers the Exit callback on the CurrentState and the Enter callback on the new state
 	 *
-	 *	TODO: document StateFinishReason
+	 *	@param StateFinishReason the reason the current state is ending i.e. the current state's
+	 *	duration elapsed
 	 */
+	UFUNCTION(BlueprintCallable)
 	void GoToState(FName NewStateName, EFFStateFinishReason StateFinishReason);
 
 	/**
@@ -82,14 +84,16 @@ public:
 	 *
 	 *	Triggers the Exit callback on the CurrentState and the Enter callback on the new state
 	 *
-	 *	TODO: document StateFinishReason
+	 *	@param StateFinishReason the reason the current state is ending i.e. the current state's
+	 *	duration elapsed
 	 */
 	void GoToState(UFFState* NewState, EFFStateFinishReason StateFinishReason);
 
 	/**
 	 *	Transitions from CurrentState to the default entry state
 	 *
-	 *	TODO: document StateFinishReason
+	 *	@param StateFinishReason the reason the current state is ending i.e. the current state's
+	 *	duration elapsed
 	 */
 	void GoToEntryState(EFFStateFinishReason StateFinishReason);
 
@@ -104,6 +108,14 @@ public:
 	UFUNCTION(BlueprintPure)
 	FORCEINLINE int64 GetTickStateWasEntered() const { return TickStateWasEntered; }
 
+    /**
+	 *	Returns the tick number which corresponds to when the On Landed event fired
+	 *
+	 *	The tick number represents the ticks that have elapsed since the game began.
+	 */
+	UFUNCTION(BlueprintPure)
+	FORCEINLINE int64 GetOnLandedTick() const { return OnLandedTick; }
+
 	UFUNCTION(BlueprintPure)
 	const UFFState* GetCurrentState() const { return const_cast<UFFState*>(CurrentState); }
 
@@ -123,16 +135,38 @@ public:
 	void SetSubStateLabel(FName InSubStateLabel);
 
     /**
-	 *
+	 * TODO: document
 	 */
 	FFFStateContext GetCurrentStateContext();
 
 	// Events
+	/**
+	 *	Called whenever state machine's owner lands on a walkable surface after they were previously falling.
+	 *
+	 *	@param Hit Hit result for the surface that was landed on
+	 */
 	virtual void Landed(const FHitResult& Hit);
 
+	/**
+	 *	@brief Called whenever the state machine's owner current movement mode changes
+	 *
+	 *	Calls appropriate Blueprint hooks.
+	 *
+	 *	@param PrevMovementMode previous movement mode.
+	 *	@param PreviousCustomMode previous movement mode if PrevMovementMode is MOVE_Custom
+	 *	@param NewMovementMode new movement mode
+	 *	@param NewCustomMode new movement mode if NewMovementMode is MOVE_Custom
+	 */ 
 	virtual void MovementModeChanged(EMovementMode PrevMovementMode, uint8 PreviousCustomMode, 
 	    EMovementMode NewMovementMode, uint8 NewCustomMode);
 
+	// TODO: document
+	virtual void AttackHit(const FHitResult& HitResult);
+	
+	// TODO: document
+	// TODO: bring HitParams struct into FightingFramework
+	virtual void TakeHit(/* const FHitParams& HitParams*/);
+	
 	FOnStateTransitionSignature OnStateTransition;
 
 	// IFFSystemInterface interface
@@ -158,19 +192,27 @@ protected:
 	int64 TicksInState;
 
     /**
-	 *	The tick number which corresponds to when this state was entered into.
+	 *	The tick number which corresponds to when the current state was entered.
 	 *
 	 *	The tick number represents the ticks that have elapsed since the game began.
 	 */
 	int64 TickStateWasEntered;
 
+    /**
+	 *	The tick number which corresponds to when the On Landed event was called for the current tick.
+	 *
+	 *	The tick number represents the ticks that have elapsed since the game began.
+	 */
+	int64 OnLandedTick;
+
 	/** Current active state for this state machine */
 	UPROPERTY()
 	UFFState* CurrentState;
 
-	/** Current SubState label or NAME_None if there is no SubState label set for the current state*/
+	/** Current SubState label or NAME_None if there is no SubState label set for the current state */
 	FName CurrentSubStateLabel;
 
+	// TODO: should be a TMap
 	// States that have been added
 	UPROPERTY()
 	TArray<UFFState*> States;

Source/UnrealFightingFramework/State/IFFStateOwnerInterface.h

@@ -2,6 +2,10 @@
 
 #pragma once
 
+// FF includes
+#include "Input/FFInputBufferComponent.h"
+
+// UE includes
 #include "CoreMinimal.h"
 #include "UObject/Interface.h"
 
@@ -14,18 +18,46 @@ class UFFStateOwnerInterface : public UInterface
 };
 
 /**
- * 
+ * TODO: document
  */
+
+// TODO: why is this an interface again?
 class UNREALFIGHTINGFRAMEWORK_API IFFStateOwnerInterface
 {
 	GENERATED_BODY()
 
 public:
+    /**
+     *	@brief Checks to see if the provided input sequence has a valid matching series of inputs in
+     *	the input buffer
+     *
+     *	@param InInputSequence sequence of inputs to check in the input buffer
+     *	@return true if the input sequence has a valid matching series of inputs in the input buffer
+     */
     UFUNCTION(BlueprintCallable, Category="UFF State Owner Interface")
     virtual bool CheckInputSequence(const FFFInputSequence& InInputSequence) = 0;
-
+	
+	/**
+	 *	@brief Checks to see if at least one of the provided input sequences has a valid matching
+	 *	series of inputs in the input buffer
+	 *
+	 *	@param InInputSequences array of sequences of inputs to check in the input buffer
+	 *	@return true if at least one input sequence has a valid matching series of inputs in the
+	 *	input buffer
+	 */
     UFUNCTION(BlueprintCallable, Category="UFF State Owner Interface")
     virtual bool CheckInputSequences(const TArray<FFFInputSequence>& InInputSequences) = 0;
 
+    /**
+     *	@brief Convert 2D movement input a 3D world direction relative to the view orientation
+     *
+     *	@return direction of player's 2D movement input in world space 
+     */
+    virtual FVector GetMoveInputAsWorldDirection() const = 0;
+
+    /**
+     *	@brief Sets the current tick's input in the input buffer as disabled, preventing it from
+     *	being considered as valid input for input sequence interpretation
+     */
     virtual void DisableMostRecentInput() = 0;
 };

Source/UnrealFightingFramework/Tests/InputBufferTests.cpp

@@ -0,0 +1,139 @@
+// Unreal Fighting Framework by Kevin Poretti
+
+// FF includes
+#include "Input/FFInputBufferComponent.h"
+
+// UE includes
+#include "CoreMinimal.h"
+#include "Misc/AutomationTest.h"
+
+#if WITH_DEV_AUTOMATION_TESTS
+
+IMPLEMENT_SIMPLE_AUTOMATION_TEST(FInputBufferTest, "FightingFramework.Input.InputBuffer",
+	EAutomationTestFlags::ApplicationContextMask | EAutomationTestFlags::ProductFilter)
+bool FInputBufferTest::RunTest(const FString& Parameters)
+{
+	TStrongObjectPtr<UWorld> World = TStrongObjectPtr(UWorld::CreateWorld(EWorldType::Game, false));
+	// Create a dummy actor
+	TStrongObjectPtr<AActor> InputBufferOwner = TStrongObjectPtr<AActor>(World->SpawnActor<AActor>());
+	TestTrue(TEXT("Create InputBufferOwner"), InputBufferOwner.IsValid());
+	UFFInputBufferComponent* InputBuffer =
+		NewObject<UFFInputBufferComponent>(InputBufferOwner.Get(), 
+		UFFInputBufferComponent::StaticClass(), TEXT("InputBuffer"));
+	InputBuffer->RegisterComponent();
+	
+	// InputBuffer must be able to be created as a subobject of an actor
+	{
+		TestNotNull(TEXT("Create new InputBuffer component"), InputBuffer);
+	}
+
+	// InputBuffer should not attempt to evaluate an input sequence if there is only one input in
+	// the buffer and should return false
+	{
+		FFFInputState InputDown;
+		InputDown.Buttons = 0x00000001;
+		
+		InputBuffer->AddInput(InputDown);
+		
+		FFFInputCondition PressedCondition;
+		PressedCondition.RequiredButtons = 0x00000001;
+		PressedCondition.RequiredButtonState = EFFButtonState::BTNS_Pressed;
+		PressedCondition.TimeoutDuration = 0;
+
+		FFFInputSequence PressedSequence;
+		PressedSequence.Sequence.Add(PressedCondition);
+		TestFalse(TEXT("Don't try to detect a sequence if only one input is present in the buffer"),
+			InputBuffer->CheckInputSequence(PressedSequence));
+	}
+
+	InputBuffer->FlushBuffer();
+
+	// InputBuffer should not attempt to evaluate an input sequence if the sequence has no input conditions
+	{
+		FFFInputState InputUp;
+		InputUp.Buttons = 0x00000000;
+		FFFInputState InputDown;
+		InputDown.Buttons = 0x00000001;
+
+		InputBuffer->AddInput(InputUp);
+		InputBuffer->AddInput(InputDown);
+
+		FFFInputSequence EmptySequence;
+		TestFalse(TEXT("Don't try to detect a sequence if the sequence has no input conditions"),
+			InputBuffer->CheckInputSequence(EmptySequence));
+	}
+
+	InputBuffer->FlushBuffer();
+	
+	// InputBuffer must detect simple button pressed condition
+	{
+		FFFInputState InputUp;
+		InputUp.Buttons = 0x00000000;
+		FFFInputState InputDown;
+		InputDown.Buttons = 0x00000001;
+
+		InputBuffer->AddInput(InputUp);
+		InputBuffer->AddInput(InputDown);
+		
+		FFFInputCondition PressedCondition;
+		PressedCondition.RequiredButtons = 0x00000001;
+		PressedCondition.RequiredButtonState = EFFButtonState::BTNS_Pressed;
+		PressedCondition.TimeoutDuration = 0;
+
+		FFFInputSequence PressedSequence;
+		PressedSequence.Sequence.Add(PressedCondition);
+		TestTrue(TEXT("Detect a single button press in the buffer"),
+			InputBuffer->CheckInputSequence(PressedSequence));
+	}
+
+	InputBuffer->FlushBuffer();
+	
+	// InputBuffer must detect simple button released condition
+	{
+		FFFInputState InputUp;
+		InputUp.Buttons = 0x0000000;
+		FFFInputState InputDown;
+		InputDown.Buttons = 0x00000001;
+
+		InputBuffer->AddInput(InputDown);
+		InputBuffer->AddInput(InputUp);
+		
+		FFFInputCondition ReleasedCondition;
+		ReleasedCondition.RequiredButtons = 0x00000001;
+		ReleasedCondition.RequiredButtonState = EFFButtonState::BTNS_Released;
+		ReleasedCondition.TimeoutDuration = 0;
+
+		FFFInputSequence ReleasedSequence;
+		ReleasedSequence.Sequence.Add(ReleasedCondition);
+		TestTrue(TEXT("Detect a single button release in the buffer"),
+			InputBuffer->CheckInputSequence(ReleasedSequence));
+	}
+
+	InputBuffer->FlushBuffer();
+	
+	// InputBuffer must detect simple button down condition
+	{
+		FFFInputState InputUp;
+		InputUp.Buttons = 0x0000000;
+		FFFInputState InputDown;
+		InputDown.Buttons = 0x00000001;
+
+		InputBuffer->AddInput(InputUp);
+		InputBuffer->AddInput(InputDown);
+		
+		FFFInputCondition DownCondition;
+		DownCondition.RequiredButtons = 0x00000001;
+		DownCondition.RequiredButtonState = EFFButtonState::BTNS_Down;
+		DownCondition.TimeoutDuration = 0;
+
+		FFFInputSequence DownSequence;
+		DownSequence.Sequence.Add(DownCondition);
+		TestTrue(TEXT("Detect a single button press in the buffer"),
+			InputBuffer->CheckInputSequence(DownSequence));
+	}
+	
+	World->DestroyWorld(false);
+	return true;
+}
+
+#endif //WITH_DEV_AUTOMATION_TESTS

Source/UnrealFightingFramework/UnrealFightingFramework.Build.cs

@@ -26,6 +26,7 @@ public class UnrealFightingFramework : ModuleRules
 			{
 				"Core",
 				"EnhancedInput",
+				"AIModule",
 				// ... add other public dependencies that you statically link with here ...
 			}
 			);

Source/UnrealFightingFramework/Utils/TCircleBuffer.h

@@ -108,6 +108,16 @@ public:
         return true;
     }
 
+	/**
+	 * @brief Flushes the buffer of all contents
+	 */
+	void Flush()
+	{
+		WriteIdx = 0;
+		ReadIdx = 0;
+		_Num = 0;
+	}
+	
     /**
      * @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.
@@ -119,7 +129,7 @@ public:
     {
         return Buffer[(ReadIdx + Index) % L];
     }
-
+	
     FORCEINLINE bool IsEmpty() const
 	{
 	    return _Num == 0;