From 7a7f15881644328e91b0c3c2d57a97b8f9eb13e5 Mon Sep 17 00:00:00 2001
From: Louis Hobbs <bazzadobs@live.co.uk>
Date: Fri, 3 Feb 2023 01:29:38 +0000
Subject: [PATCH] Add EnemyAIController class

---
 Source/Nakatomi/EnemyAIController.cpp | 112 ++++++++++++++++++++++++++
 Source/Nakatomi/EnemyAIController.h   |  48 +++++++++++
 2 files changed, 160 insertions(+)
 create mode 100644 Source/Nakatomi/EnemyAIController.cpp
 create mode 100644 Source/Nakatomi/EnemyAIController.h

diff --git a/Source/Nakatomi/EnemyAIController.cpp b/Source/Nakatomi/EnemyAIController.cpp
new file mode 100644
index 0000000..411525b
--- /dev/null
+++ b/Source/Nakatomi/EnemyAIController.cpp
@@ -0,0 +1,112 @@
+// Fill out your copyright notice in the Description page of Project Settings.
+
+#include "EnemyAIController.h"
+#include "Engine/EngineTypes.h"
+#include "Components/CapsuleComponent.h"
+
+AEnemyAIController::AEnemyAIController(const FObjectInitializer& object_initializer)
+{
+	Blackboard = CreateDefaultSubobject<UBlackboardComponent>(TEXT("Blackboard"));
+	BehaviorTree = CreateDefaultSubobject<UBehaviorTreeComponent>(TEXT("Behavior Tree"));
+}
+
+void AEnemyAIController::OnPossess(APawn* InPawn)
+{
+	Super::OnPossess(InPawn);
+
+	auto enemy = Cast<AEnemyCharacter>(InPawn);
+	check(enemy);
+
+	SetPerceptionComponent(*enemy->GetPerceptionComponent());
+	enemy->GetPerceptionComponent()->OnPerceptionUpdated.AddDynamic(this, &AEnemyAIController::OnPerceptionUpdated);
+	enemy->GetCharacterMovement()->MaxWalkSpeed = 500.f;
+	enemy->GetHealthComponent()->OnDamaged.BindUFunction(this, "OnDamaged");
+	enemy->GetHealthComponent()->OnDeath.BindUFunction(this, "OnDeath");
+	
+	if (auto behaviourTree = enemy->GetBehaviourTree())
+	{
+		Blackboard->InitializeBlackboard(*behaviourTree->BlackboardAsset);
+		BehaviorTree->StartTree(*behaviourTree);
+	}
+
+	//ensure(enemy->GetMovementComponent()->UseAccelerationForPathFollowing());
+}
+
+void AEnemyAIController::Tick(float DeltaTime)
+{
+	Super::Tick(DeltaTime);
+}
+
+AEnemyCharacter* AEnemyAIController::GetEnemyCharacter()
+{
+	return Cast<AEnemyCharacter>(GetCharacter());
+}
+
+void AEnemyAIController::OnDamaged(FDamageInfo info)
+{
+	if (GetEnemyCharacter()->GetHealthComponent()->GetCurrentHealth() > 0.0f)
+	{
+		// TODO: Do stuff here
+	}
+}
+
+void AEnemyAIController::OnDeath(FDamageInfo info)
+{
+	// TODO: Do stuff here
+
+	auto enemy = GetEnemyCharacter();
+
+	enemy->DetachFromControllerPendingDestroy();
+	enemy->GetCapsuleComponent()->SetCollisionEnabled(ECollisionEnabled::NoCollision);
+	enemy->GetCapsuleComponent()->SetCollisionResponseToAllChannels(ECollisionResponse::ECR_Ignore);
+	
+	enemy->GetMesh()->SetCollisionProfileName("Ragdoll");
+	enemy->SetActorEnableCollision(true);
+
+	enemy->GetMesh()->SetAllBodiesSimulatePhysics(true);
+	enemy->GetMesh()->SetSimulatePhysics(true);
+	enemy->GetMesh()->WakeAllRigidBodies();
+	enemy->GetMesh()->bBlendPhysics = true;
+
+	if (auto characterMovementComponent = enemy->GetCharacterMovement())
+	{
+		characterMovementComponent->StopMovementImmediately();
+		characterMovementComponent->DisableMovement();
+		characterMovementComponent->SetComponentTickEnabled(false);
+	}
+
+	enemy->SetLifeSpan(10.0f);
+}
+
+void AEnemyAIController::OnPerceptionUpdated(const TArray<AActor*>& actors)
+{
+	for (auto actor : actors)
+	{
+		if (!actor->GetClass()->IsChildOf(APlayerCharacter::StaticClass()))
+		{
+			continue;
+		}
+
+		FActorPerceptionBlueprintInfo perceptionInfo;
+		GetPerceptionComponent()->GetActorsPerception(actor, perceptionInfo);
+
+		for (auto& stimulus : perceptionInfo.LastSensedStimuli)
+		{
+			if (!stimulus.IsValid() || stimulus.IsExpired())
+			{
+				continue;
+			}
+
+			if (stimulus.IsActive())
+			{
+				PlayerCharacter = Cast<APlayerCharacter>(actor);
+				SetFocus(PlayerCharacter, EAIFocusPriority::Gameplay);
+			}
+			else
+			{
+				PlayerCharacter = nullptr;
+				SetFocus(nullptr, EAIFocusPriority::Gameplay);
+			}
+		}
+	}
+}
diff --git a/Source/Nakatomi/EnemyAIController.h b/Source/Nakatomi/EnemyAIController.h
new file mode 100644
index 0000000..ffda70c
--- /dev/null
+++ b/Source/Nakatomi/EnemyAIController.h
@@ -0,0 +1,48 @@
+// Fill out your copyright notice in the Description page of Project Settings.
+
+#pragma once
+
+#include "CoreMinimal.h"
+#include "AIController.h"
+#include "BehaviorTree/BehaviorTreeComponent.h"
+#include "BehaviorTree/BehaviorTree.h"
+#include "BehaviorTree/BlackboardComponent.h"
+#include "EnemyCharacter.h"
+#include "GameFramework/CharacterMovementComponent.h"
+#include "PlayerCharacter.h"
+#include "EnemyAIController.generated.h"
+
+/**
+ * 
+ */
+UCLASS()
+class NAKATOMI_API AEnemyAIController : public AAIController
+{
+	GENERATED_BODY()
+
+private:
+
+	UBlackboardComponent* Blackboard;
+
+	UBehaviorTreeComponent* BehaviorTree;
+
+	APlayerCharacter* PlayerCharacter;
+
+public:
+	AEnemyAIController(const FObjectInitializer& object_initializer);
+
+	virtual void OnPossess(APawn* InPawn) override;
+
+	virtual void Tick(float DeltaTime) override;
+
+	virtual AEnemyCharacter* GetEnemyCharacter();
+
+	UFUNCTION()
+	virtual void OnDamaged(FDamageInfo info);
+
+	UFUNCTION()
+	virtual void OnDeath(FDamageInfo info);
+
+	UFUNCTION()
+	void OnPerceptionUpdated(const TArray<AActor*>& actors);
+};