From 2f22223776765f3599c8843afae9763370b3ce3b Mon Sep 17 00:00:00 2001
From: Kevin Poretti <kevinporetti@gmail.com>
Date: Fri, 10 Nov 2023 10:05:16 -0500
Subject: [PATCH] Poll inputs outside of game logic tick

---
 .../GameplayFramework/FFGameState.cpp         | 40 +++++++++++++++++++
 .../Input/FFPlayerController.cpp              |  2 +-
 .../Input/FFPlayerController.h                | 11 ++---
 3 files changed, 47 insertions(+), 6 deletions(-)

diff --git a/Source/UnrealFightingFramework/GameplayFramework/FFGameState.cpp b/Source/UnrealFightingFramework/GameplayFramework/FFGameState.cpp
index ebb0e9a..03c7ff0 100644
--- a/Source/UnrealFightingFramework/GameplayFramework/FFGameState.cpp
+++ b/Source/UnrealFightingFramework/GameplayFramework/FFGameState.cpp
@@ -1,7 +1,12 @@
 // Project Sword & Gun Copyright Kevin Poretti
 
+// FF includes
+#include "Input/FFPlayerController.h"
 #include "GameplayFramework/FFGameState.h"
 
+// UE includes
+#include "Kismet/GameplayStatics.h"
+
 void AFFGameState::OnFixedTick(float OneTick)
 {
 }
@@ -11,15 +16,50 @@ 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();
 }
diff --git a/Source/UnrealFightingFramework/Input/FFPlayerController.cpp b/Source/UnrealFightingFramework/Input/FFPlayerController.cpp
index b3a52c8..24a059b 100644
--- a/Source/UnrealFightingFramework/Input/FFPlayerController.cpp
+++ b/Source/UnrealFightingFramework/Input/FFPlayerController.cpp
@@ -49,7 +49,7 @@ FVector AFFPlayerController::GetInputAsWorldDirection() const
 }
 
 
-void AFFPlayerController::FixedTick(float OneFrame)
+void AFFPlayerController::AddCurrentInputToBuffer()
 {
     //UnacknowledgedInputs.Push(RawInput);
     InputBuffer->AddInput(ModifiedInput);
diff --git a/Source/UnrealFightingFramework/Input/FFPlayerController.h b/Source/UnrealFightingFramework/Input/FFPlayerController.h
index 8df7814..da47354 100644
--- a/Source/UnrealFightingFramework/Input/FFPlayerController.h
+++ b/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()
 
@@ -54,15 +54,16 @@ public:
 	UFUNCTION(BlueprintPure)
     bool HasMoveInput();
 
+	// TODO: document
 	void ConsumeMoveInput();
 
+	// TODO: document
 	FVector GetInputAsWorldDirection() const;
 
-	// IFFSystemInterface interface
-	virtual void FixedTick(float OneFrame) override;
-	// End of IFFSystemInterface
+	// TODO: document
+    void AddCurrentInputToBuffer();
 
-	// IFFStateOwnerInterface
+    // IFFStateOwnerInterface
 	UFUNCTION()
 	virtual bool CheckInputSequence(const FFFInputSequence& InInputSequence) override;