Building-Escape/Grabber.cpp at master · christinec-dev/Building-Escape · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
//Copyright Christine Coomans 2021

#include "Grabber.h"
#include "DrawDebugHelpers.h"
#include "Engine/World.h"
#include "GameFramework/PlayerController.h"

//Allows us to use out parameters - useless
#define OUT

// Sets default values for this component's properties
UGrabber::UGrabber()
{
	PrimaryComponentTick.bCanEverTick = true;
}

// Called when the game starts
void UGrabber::BeginPlay()
{
	Super::BeginPlay();
	FindPhysicsHandle();
	SetupInputComponent();
}

//Game Input
void UGrabber::SetupInputComponent()
{
	//InputComponent To Allow Player To Interact
	InputComponent = GetOwner()->FindComponentByClass<UInputComponent>();
	if (InputComponent) {
		//"Grab" Must Be Same As Input In Project Settings
		InputComponent->BindAction("Grab", IE_Pressed, this, &UGrabber::Grab);
		InputComponent->BindAction("Grab", IE_Released, this, &UGrabber::Release);
	}
}

//Game Physics
void UGrabber::FindPhysicsHandle()
{
	//Checks for Physics Handle Component
	PhysicsHandle = GetOwner()->FindComponentByClass<UPhysicsHandleComponent>();
	//Crash Protection
	if(!PhysicsHandle) {
		UE_LOG(LogTemp, Error, TEXT("No Physics Handle Found On : %s"), *GetOwner()->GetName());
	}
}

//Press Right Mouse Button
void UGrabber::Grab()
{
	//Only Log Collision In Reach When Key Clicked
	FHitResult HitResult = GetFirstPhysicsBodyInReach();
	UPrimitiveComponent* ComponentToGrab = HitResult.GetComponent();
	AActor* ActorHit = HitResult.GetActor();

	//If We Grab Something, Attach Physics Handle
	if (ActorHit)
	{
		if (!PhysicsHandle) {return;}
		PhysicsHandle->GrabComponentAtLocation(
			ComponentToGrab,
			NAME_None,
			GetPlayersReach()
		);
	}
}

//Release Right Mouse Button
void UGrabber::Release()
{
	//Removes Physics Handle
	if (!PhysicsHandle) {return;}
	PhysicsHandle->ReleaseComponent();
}


// Called Every Frame
void UGrabber::TickComponent(float DeltaTime, ELevelTick TickType, FActorComponentTickFunction* ThisTickFunction)
{
	Super::TickComponent(DeltaTime, TickType, ThisTickFunction);

	//If Physics Handle Is Attached, Then Set Target Location
	if (!PhysicsHandle) {return;}
	if (PhysicsHandle->GrabbedComponent) {
		PhysicsHandle->SetTargetLocation(GetPlayersReach());
	}
}

// Line Tracing
FHitResult UGrabber::GetFirstPhysicsBodyInReach() const
{
	FHitResult Hit;

	//Ray Cast
	FCollisionQueryParams TraceParams(FName(TEXT("")), false, GetOwner());

	GetWorld()->LineTraceSingleByObjectType(
		OUT Hit,
		GetPlayersWorldPos(),
		GetPlayersReach(),
		FCollisionObjectQueryParams(ECollisionChannel::ECC_PhysicsBody),
		TraceParams
	);

	return Hit;
}

// Gets Player ViewPoint
FVector UGrabber::GetPlayersWorldPos() const
{
	//Gets Player ViewPoint
	FVector PlayerViewPointLocation;
	FRotator PlayerViewPointRotation;

	GetWorld()->GetFirstPlayerController()->GetPlayerViewPoint(
		OUT PlayerViewPointLocation,
		OUT PlayerViewPointRotation
	);

	//We use Ray-Cast (Line Tracing) - To Help Indicate Object Contact
	return PlayerViewPointLocation;
}

// Gets Player ReachPoint
FVector UGrabber::GetPlayersReach() const {
	FVector PlayerViewPointLocation;
	FRotator PlayerViewPointRotation;

	GetWorld()->GetFirstPlayerController()->GetPlayerViewPoint(
		OUT PlayerViewPointLocation,
		OUT PlayerViewPointRotation
	);

	//We use Ray-Cast (Line Tracing) - To Help Indicate Object Contact
	return PlayerViewPointLocation + PlayerViewPointRotation.Vector() * Reach;
}