#include "CameraCaptureActor.h"

#include "Components/SceneCaptureComponent2D.h"
#include "Camera/CameraComponent.h"
#include "Engine/TextureRenderTarget2D.h"



ACameraCaptureActor::ACameraCaptureActor()
{
    // PrimaryActorTick.bCanEverTick = false;
}

void ACameraCaptureActor::BeginPlay()
{
    Super::BeginPlay();
    BuildViewCaptures();
}

#if WITH_EDITOR
void ACameraCaptureActor::PostEditChangeProperty(FPropertyChangedEvent& PropertyChangedEvent)
{
    Super::PostEditChangeProperty(PropertyChangedEvent);

    // 任何关键参数变化都重建（避免 RT 尺寸/数量不匹配）
    BuildViewCaptures();
}
#endif

void ACameraCaptureActor::BuildViewCaptures()
{
    if (ViewCapture)
    {
        ViewCapture->DestroyComponent();
        ViewCapture = nullptr;
    }

    if (ViewRT)
    {
        ViewRT = nullptr;
    }

    ViewRT = NewObject<UTextureRenderTarget2D>(this);
    ViewRT->ClearColor = FLinearColor::Black;
    ViewRT->InitAutoFormat(ViewWidth, ViewHeight);
    ViewRT->UpdateResourceImmediate(true);

    ViewCapture = NewObject<USceneCaptureComponent2D>(this, TEXT("ViewCapture"));
    ViewCapture->SetupAttachment(GetRootComponent());
    ViewCapture->RegisterComponent();

    ViewCapture->TextureTarget = ViewRT;
    ViewCapture->CaptureSource = ESceneCaptureSource::SCS_FinalColorHDR;
    ViewCapture->bCaptureEveryFrame = false;
    ViewCapture->bCaptureOnMovement = false;

    ViewCapture->PostProcessBlendWeight = 1.0f;

    ViewCapture->PostProcessSettings.bOverride_AutoExposureMethod = true;
    ViewCapture->PostProcessSettings.AutoExposureMethod = EAutoExposureMethod::AEM_Manual;

    ViewCapture->PostProcessSettings.bOverride_AutoExposureBias = true;
    ViewCapture->PostProcessSettings.AutoExposureBias = 1.0f;

    ViewCapture->SetRelativeLocation(FVector::ZeroVector);
    ViewCapture->SetRelativeRotation(FRotator::ZeroRotator);
}

void ACameraCaptureActor::UpdateViewTransforms(const int32 Index)
{
    // 以本 Actor（CameraActor）的 transform 为中心
    const FVector Center = GetActorLocation();
    const FRotator Rot = GetActorRotation();
    const FVector Right = Rot.Quaternion().GetRightVector();

    // FOV 从主 CameraComponent 取
    float FOV = 90.f;
    if (UCameraComponent* Cam = GetCameraComponent())
    {
        FOV = Cam->FieldOfView;
    }

    if (ViewCapture)
    {
        // 线性水平分布：居中对称
        const float Offset = (Index - (ViewCount - 1) * 0.5f) * Baseline;
        const FVector Pos = Center + Right * Offset;

        ViewCapture->SetWorldLocationAndRotation(Pos, Rot);
        ViewCapture->FOVAngle = FOV;
    }
}

void ACameraCaptureActor::CaptureViews()
{
    ViewCapture->CaptureScene();
}