SyncPhysics.cpp

#include "SyncPhysics.h"
#include "GameFramework/Actor.h"
#include "Components/PrimitiveComponent.h"
#include "Net/UnrealNetwork.h"

USyncPhysics::USyncPhysics()
{
    PrimaryComponentTick.bCanEverTick = true;
    SetIsReplicatedByDefault(true);
    bEnablePhysicsReplication = true;
}

void USyncPhysics::BeginPlay()
{
    Super::BeginPlay();

    if (GetOwner())
    {
        RootComp = Cast<UPrimitiveComponent>(GetOwner()->GetRootComponent());
    }
}

void USyncPhysics::TickComponent(float DeltaTime, ELevelTick TickType, FActorComponentTickFunction* ThisTickFunction)
{
    Super::TickComponent(DeltaTime, TickType, ThisTickFunction);

    if (bEnablePhysicsReplication)
    {
        ReplicatePhysics();
    }
}

void USyncPhysics::ReplicatePhysics()
{
    if (RootComp && RootComp->IsSimulatingPhysics())
    {
        FVector NewPosition = RootComp->GetComponentLocation();
        FVector NewVelocity = RootComp->GetPhysicsLinearVelocity();
        FRotator NewRotation = RootComp->GetComponentRotation();

        if (GetOwner()->HasAuthority())
        {
            Server_SyncPhysicsState(NewPosition, NewVelocity, NewRotation);
        }
        else
        {
            ApplyPhysicsState(LastPosition, LastVelocity, LastRotation);
        }
    }
}

void USyncPhysics::ApplyPhysicsState(const FVector& NewPosition, const FVector& NewVelocity, const FRotator& NewRotation)
{
    if (RootComp)
    {
        RootComp->SetWorldLocation(NewPosition);
        RootComp->SetPhysicsLinearVelocity(NewVelocity);
        RootComp->SetWorldRotation(NewRotation);
    }
}

void USyncPhysics::Server_SyncPhysicsState_Implementation(const FVector& NewPosition, const FVector& NewVelocity, const FRotator& NewRotation)
{
    LastPosition = NewPosition;
    LastVelocity = NewVelocity;
    LastRotation = NewRotation;
}

bool USyncPhysics::Server_SyncPhysicsState_Validate(const FVector& NewPosition, const FVector& NewVelocity, const FRotator& NewRotation)
{
    return true;
}

void USyncPhysics::GetLifetimeReplicatedProps(TArray<FLifetimeProperty>& OutLifetimeProps) const
{
    Super::GetLifetimeReplicatedProps(OutLifetimeProps);

    DOREPLIFETIME(USyncPhysics, LastPosition);
    DOREPLIFETIME(USyncPhysics, LastVelocity);
    DOREPLIFETIME(USyncPhysics, LastRotation);
}