// Fill out your copyright notice in the Description page of Project Settings.


#include "IronBlock.h"
// 确保包含了 RDG 所需的头文件
#include "RenderGraphBuilder.h"
#include "RenderGraphUtils.h" // FComputeShaderUtils::AddPass
#include "FDeformComputeShader.h" // 确保这个头文件存在且包含了 FDeformationCSDispatchParams
#include "StaticMeshResources.h"
#include "TextureResource.h"
#include "Engine/TextureRenderTarget2D.h"
#include "Engine/StaticMesh.h"
#include "Engine/Texture2D.h"
#include "Materials/MaterialInstanceDynamic.h"
#include "PhysicsEngine/BodySetup.h"
#include "RHICommandList.h"
#include "Engine/Texture.h"
#include "GenericPlatform/GenericPlatformProcess.h"
#include "Kismet/GameplayStatics.h"
#include "Kismet/KismetRenderingLibrary.h"


// Sets default values
AIronBlock::AIronBlock() : StaticMeshComp(nullptr), DeformBaseMat(nullptr), DeformCalMat(nullptr),
PositionRenderTarget0(nullptr), PositionRenderTarget1(nullptr),
DynMaterial(nullptr), DynCalMaterial(nullptr)
{
	// Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.
	PrimaryActorTick.bCanEverTick = true;
	RootComponent = CreateDefaultSubobject<USceneComponent>(TEXT("Root"));
	StaticMeshComp = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("StaticMeshComponent"));
	StaticMeshComp->AttachToComponent(RootComponent,FAttachmentTransformRules::SnapToTargetIncludingScale);
	//RootComponent = StaticMeshComp;
}
void AIronBlock::PostInitProperties()
{
	// 必须调用父类实现
	Super::PostInitProperties();

	// 检查：如果 StaticMeshComp 没有被赋予任何网格（即在编辑器中没有设置）
	// 并且我们正在处理 Class Default Object (CDO)，通常用来设置类级的默认值
	if (StaticMeshComp && !StaticMeshComp->GetStaticMesh())
	{
		// 只有当网格为空时，才加载并设置默认的 Cube
		UStaticMesh* DefaultMesh = LoadObject<UStaticMesh>(nullptr, TEXT("/Engine/BasicShapes/Cube"));
		if (DefaultMesh)
		{
			StaticMeshComp->SetStaticMesh(DefaultMesh);
		}
	}
}
// Called when the game starts or when spawned
void AIronBlock::BeginPlay()
{
	Super::BeginPlay();
	InitializePositionTexture();
}

/**
 * 核心修复：创建一个配置好用于变形计算的 RenderTarget
 */
UTextureRenderTarget2D* AIronBlock::CreateDeformRT(const FString& RTName, int32 Size)
{
	UTextureRenderTarget2D* RenderTarget = NewObject<UTextureRenderTarget2D>(this, FName(*RTName));
	if (RenderTarget)
	{
		RenderTarget->InitCustomFormat(Size, Size, PF_A32B32G32R32F, false);
		RenderTarget->bNeedsTwoCopies = true; // 告知引擎这个纹理会被用于Ping-Pong，优化内存
		RenderTarget->SizeX = Size;
		RenderTarget->SizeY = Size;
		RenderTarget->bAutoGenerateMips = false;
		RenderTarget->AddressX = TA_Clamp;
		RenderTarget->AddressY = TA_Clamp;
		FLinearColor ClearColor = FLinearColor(0.5f, 0.5f, 0.5f, 1.0f);
		RenderTarget->ClearColor = ClearColor;
		// 立即创建RHI资源
		RenderTarget->UpdateResource();

        // 调用 Kismet Rendering Library 的清除函数
        UKismetRenderingLibrary::ClearRenderTarget2D(
            this->GetWorld(), // 通常传入你的 World 或 Actor
            RenderTarget,
            ClearColor
        );
		//FlushRenderingCommands();
		//RenderTarget->UpdateResourceImmediate(true);
	}
	return RenderTarget;
}


void AIronBlock::InitializePositionTexture()
{
	// --- 关键修复: 创建两个 RenderTarget ---
	PositionRenderTarget0 = CreateDeformRT(TEXT("PositionRT0"), TexSize);
	PositionRenderTarget1 = CreateDeformRT(TEXT("PositionRT1"), TexSize);

	// 设置变形材质
	SetupDeformationMaterial(nullptr);
	UE_LOG(LogTemp, Log, TEXT("Position textures initialized"));
}

void AIronBlock::SetupDeformationMaterial(UTexture2D* OrigTex)
{
	// 创建动态材质实例
	if (StaticMeshComp)
	{
		if (!DeformBaseMat)
		{
			DeformBaseMat = LoadObject<UMaterial>(nullptr, TEXT("/Game/Res/Materials/M_Iron"));
		}
		if (!DeformBaseMat)
		{
			DeformBaseMat = LoadObject<UMaterial>(nullptr, TEXT("/Engine/BasicShapes/BasicShapeMaterial"));
		}
		if (!DeformCalMat)
		{
			DeformCalMat = LoadObject<UMaterial>(nullptr, TEXT("/Game/Res/Materials/M_HitCal"));
		}
		if (!DeformCalMat)
		{
			DeformCalMat = LoadObject<UMaterial>(nullptr, TEXT("/Engine/BasicShapes/BasicShapeMaterial"));
		}
		if (DeformBaseMat && DeformCalMat)
		{
			DynMaterial = UMaterialInstanceDynamic::Create(DeformBaseMat, this);
			DynCalMaterial = UMaterialInstanceDynamic::Create(DeformCalMat, this);
			StaticMeshComp->SetMaterial(0, DynMaterial);
			// 设置初始参数
			if (DynMaterial)
			{
				// 初始时读取 RT0
				DynMaterial->SetTextureParameterValue(TEXT("PositionTexture"), PositionRenderTarget0);
			}
		}
		else
		{
			UE_LOG(LogTemp, Warning, TEXT("Failed to load base material for iron block"));
		}
	}
}

void AIronBlock::OnHammerHit(const FHitResult& HitResult)
{
	// 获取锤子冲击力
	FVector2D HitUV;
	UGameplayStatics::FindCollisionUV(HitResult,0,HitUV);
	FVector ImpactNormal = -HitResult.ImpactNormal;
	float DeformationRadius = ImpactAffectRange/TexSize;
	UTextureRenderTarget2D* LastTex = nullptr;
	UTextureRenderTarget2D* CurTex = nullptr;
	if(CurrentTextureIndex == 0)
	{
		LastTex = PositionRenderTarget0;
		CurTex = PositionRenderTarget1;
	}
	else
	{
		LastTex = PositionRenderTarget1;
		CurTex = PositionRenderTarget0;
	}
	if(DynCalMaterial)
	{
		DynCalMaterial->SetVectorParameterValue(TEXT("ImpactUV"), FLinearColor(HitUV.X,HitUV.Y,0,0));
		DynCalMaterial->SetScalarParameterValue(TEXT("ImpactForce"),ImpactForce);
		DynCalMaterial->SetScalarParameterValue(TEXT("ImpactRadius"), DeformationRadius);
		DynCalMaterial->SetVectorParameterValue(TEXT("ImpactNormal"),ImpactNormal);
		DynCalMaterial->SetTextureParameterValue(TEXT("LastPosition"),LastTex);
		UKismetRenderingLibrary::DrawMaterialToRenderTarget(this->GetWorld(),CurTex,DynCalMaterial);
	}
	if(DynMaterial)
	{
		DynMaterial->SetTextureParameterValue(TEXT("PositionTexture"),CurTex);
		CurrentTextureIndex = 1 - CurrentTextureIndex;
	}
}

// Called every frame
void AIronBlock::Tick(float DeltaTime)
{
	Super::Tick(DeltaTime);
}