MagicWand.h

#pragma once

#include "CoreMinimal.h"
#include "MagicWandSelectionManager.h"
#include "ProceduralMeshComponent.h"
#include "MetaCastBaseline.h"
#include "Generators/MarchingCubes.h"
#include "Templates/Atomic.h"
#include "MagicWand.generated.h"

UCLASS( ClassGroup=(Custom), meta=(BlueprintSpawnableComponent) )
class UMagicWand : public UMetaCastBaseline
{
	GENERATED_BODY()

	//	MAGIC WAND

	TAtomic<bool> AbortMagicWand = false;
	TSharedPtr<FSelectionManager> CurrentSelection;
	TMap<float, TSharedPtr<FSelectionManager>> SelectionCache;
	TArray<float> SortedProximityRanges;
	FVector SeedPointPositionLocal;
	FDensityField* MyDensityField;
	float CountSelectionTime = 0;
	bool IsMagicWandInitialized = false;

	//	THREADING
	
	mutable FCriticalSection ProceduralMeshGuard;
	mutable FCriticalSection SelectionCacheLock;
	mutable FCriticalSection ThreadNumberLock;
	mutable FThreadSafeCounter NumberThreads = 0;

	//	VISUALIZATION
	
	bool IsMarchingCubesRunning = false;
	bool AbortMarchingCubes = false;
	float MarchingCubeSize = 0;
		
	//	REFERENCES
	
	UPROPERTY()
	UWorld* World;
	
	UPROPERTY()
	ULineBatchComponent* MyLineBatchComponent;

	UPROPERTY()
	UProceduralMeshComponent* ProceduralMesh;
	
	UPROPERTY()
	UProceduralMeshComponent* MarchingCubeMesh;
	
	//	USER EDITABLE PROPERTIES

	UPROPERTY(EditAnywhere)
	float MagicWandUpdatesPerSecond = 3;
	
	UPROPERTY(EditAnywhere)
	float ThresholdDistanceScaling = 20;

	UPROPERTY(EditAnywhere)
	float MinThreshold = 0.1;
	
	UPROPERTY(EditAnywhere)
	float MaxThreshold = 8;
		
	UPROPERTY(EditAnywhere)
	UMaterialInterface* SelectionVolumeMat;
	
	UPROPERTY(EditAnywhere)
	int MaxThreadCount = 100;

	UPROPERTY(EditAnywhere)
	bool UpdateMagicWandDuringDrag = false;
	
public:
	int32 SeedPointIndex;
	
	//	INITIALIZATION
	
	UMagicWand();
	virtual void BeginPlay() override;
	void InitReferences();
	void InitProceduralMesh() const;

	//	INPUT HANDLING
	
	virtual void SelectionEndAction() override;
	virtual void SelectionStartAction() override;
	virtual void HandleMetaEraseReleased(const FInputActionInstance& Instance) override;
	virtual void HandleUndoAction(const FInputActionInstance& Instance) override;
	virtual void HandleRedoAction(const FInputActionInstance& Instance) override;
	virtual void EraseParticles(const FVector& InputPosition) override;

	//	VISUALIZATION
	
	void GenerateVoxelMeshWithCubes(const TArray<int32> Voxels) const;
	void GenerateVoxelMeshSmooth(const TSet<int32>& Voxels);

	//	MAGIC WAND SELECTION

	void InitMagicWandSelection();
	void PerformMagicWandSelection(const float ProximityThreshold);
	void FindSeed(const FVector& InputPosition);
	void ExpandFromAllPointsInQueue(TQueue<int32>* ProcessQueue, const float ProximityThreshold, int ThreadLoad);
	void ExpandFromPoint(TQueue<int32>* ProcessQueue, const float ProximityThreshold, int& ThreadLoad, const FVector& ExpansionPoint, const FVoxelPointLookupTable* MyVoxelPointLookupTable) const;
	void FinishSelectionThread(const float ProximityThreshold);
	void CreateNewExpansionThread(TQueue<int32>* ProcessQueue, int& NumberToProcess, const float ProximityThreshold);
	void CacheSelectionResults(const float ProximityThreshold, const TSharedPtr<FSelectionManager>& SelectionResults);
	TSharedPtr<FSelectionManager> GetSelectionCacheResultCopy(float ProximityThreshold);

	//	TICK
	
	virtual void TickComponent(float DeltaTime, ELevelTick TickType, FActorComponentTickFunction* ThisTickFunction) override;
	virtual void SelectParticles(const FVector& InputPosition) override;
	void DrawPersistentLine(const FVector& Start, const FVector& End, const FColor& Color, float Duration, float Thickness) const;
	void GenerateCylinderBetweenPoints(const FVector& Start, const FVector& End, const float Radius, const int32 NumSides, const FColor Color, const int MeshSectionIndex) const;
};