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


#include "LRRenderUtilLibrary.h"

#include "Components/SceneCaptureComponent2D.h"
#include "Engine/TextureRenderTarget2D.h"
#include "Kismet/KismetRenderingLibrary.h"

void ULRRenderUtilLibrary::SetupSceneCaptureForMesh(USceneCaptureComponent2D* SceneCapture, UStaticMeshComponent* MeshComp)
{
	if (!SceneCapture || !MeshComp)
	{
		return;
	}

	// Set the scene capture to focus on the mesh
	SceneCapture->ShowOnlyComponent(MeshComp);
    
	SceneCapture->CaptureSource = ESceneCaptureSource::SCS_BaseColor;
	SceneCapture->bCaptureEveryFrame = false;
	SceneCapture->bCaptureOnMovement = false;
	SceneCapture->FOVAngle = 90.f;
    
	// Set a solid background color (black by default)
	SceneCapture->CompositeMode = ESceneCaptureCompositeMode::SCCM_Overwrite;
	SceneCapture->TextureTarget->ClearColor = FLinearColor::Transparent;

	// Adjust the transform to frame the mesh
	FVector MeshBounds = MeshComp->Bounds.BoxExtent;
	FVector MeshOrigin = MeshComp->Bounds.Origin;

	// Calculate the camera distance
	float CameraDistance = MeshBounds.Size() * 1.1f; // Adjust multiplier as needed

	// Calculate the camera location
	FVector CameraLocation = MeshOrigin + FVector(CameraDistance, 0.f, 0.f); // Default to capturing from the +X axis

	// Calculate the camera rotation
	FRotator CameraRotation = (MeshOrigin - CameraLocation).Rotation();
    
	SceneCapture->SetWorldLocationAndRotation(CameraLocation, CameraRotation); // Adjust rotation as needed
}

UTextureRenderTarget2D* ULRRenderUtilLibrary::CaptureMeshToRenderTarget(UStaticMeshComponent* MeshComp, const FVector2D& ImageSize, UObject* WorldContextObject)
{
	if (!MeshComp || !WorldContextObject)
	{
		return nullptr;
	}

	// Create a render target
	UTextureRenderTarget2D* RenderTarget = UKismetRenderingLibrary::CreateRenderTarget2D(
		WorldContextObject, ImageSize.X, ImageSize.Y, ETextureRenderTargetFormat::RTF_RGBA8);

	if (!RenderTarget)
	{
		return nullptr;
	}

	// Create a temporary actor to hold the scene capture component
	AActor* TempActor = WorldContextObject->GetWorld()->SpawnActor<AActor>();
	USceneCaptureComponent2D* SceneCapture = NewObject<USceneCaptureComponent2D>(TempActor);
	SceneCapture->AttachToComponent(TempActor->GetRootComponent(), FAttachmentTransformRules::KeepRelativeTransform);
	SceneCapture->TextureTarget = RenderTarget;

	// Setup the scene capture
	SetupSceneCaptureForMesh(SceneCapture, MeshComp);

	UKismetRenderingLibrary::ClearRenderTarget2D(WorldContextObject, SceneCapture->TextureTarget, FLinearColor::Transparent);

	// Disable post-processing effects
	SceneCapture->PostProcessSettings.bOverride_AutoExposureMethod = true;
	SceneCapture->PostProcessSettings.AutoExposureMethod = EAutoExposureMethod::AEM_Manual;
	SceneCapture->PostProcessSettings.bOverride_AutoExposureBias = true;
	SceneCapture->PostProcessSettings.AutoExposureBias = 1.0f;
	SceneCapture->PostProcessSettings.bOverride_BloomIntensity = true;
	SceneCapture->PostProcessSettings.BloomIntensity = 0.0f;
    
	// Trigger a one-time capture
	SceneCapture->CaptureScene();

	// Clean up the temporary actor
	TempActor->Destroy();
    
	return RenderTarget;
}