// Copyright Epic Games, Inc. All Rights Reserved.

#pragma once 

#include "ChaosClothAsset/SimulationBaseConfigNode.h"
#include "ChaosClothAsset/WeightedValue.h"
#include "ChaosClothAsset/SimulationConfigNodePropertyTypes.h"
#include "SimulationPBDBendingElementConfigNode.generated.h"

/** Bending element constraint property configuration node. */
USTRUCT(Meta = (DataflowCloth, Deprecated = "5.4"))
struct FChaosClothAssetSimulationPBDBendingElementConfigNode : public FChaosClothAssetSimulationBaseConfigNode
{
	GENERATED_USTRUCT_BODY()
	DATAFLOW_NODE_DEFINE_INTERNAL(FChaosClothAssetSimulationPBDBendingElementConfigNode, "SimulationPBDBendingElementConfig", "Cloth", "Cloth Simulation PBD Bending Element Config")

public:
	/**
	 * Method for calculating the rest angles of the constraints.
	 */
	UPROPERTY(EditAnywhere, Category = "PBDBendingElement Properties")
	EChaosClothAssetRestAngleConstructionType RestAngleType = EChaosClothAssetRestAngleConstructionType::Use3DRestAngles;

	/**
	 * Calculate rest angles as a ratio between completely flat and whatever is the 3D rest angle.
	 * When FlatnessRatio = 0, this is equivalent to "Use3DRestAngles".
	 * When FlatnessRatio = 1, the rest angle will be 0 (completely flat).
	 * If a valid weight map is found with the given Weight Map name, then both Low and High values
	 * are interpolated with the per particle weight to make the final value used for the simulation.
	 * Otherwise all particles are considered to have a zero weight, and only the Low value is meaningful.
	 */
	UPROPERTY(EditAnywhere, Category = "PBDBendingElement Properties", Meta = (UIMin = "0", UIMax = "1", ClampMin = "0", ClampMax = "1", EditCondition = "RestAngleType == EChaosClothAssetRestAngleConstructionType::FlatnessRatio"))
	FChaosClothAssetWeightedValueNonAnimatable FlatnessRatio = { 0.f, 0.f, TEXT("FlatnessRatio") };

	/**
	 * Set rest angles to be the explicit value set here (in degrees).
	 * 0 = Flat, Positive values fold away from the edge normal, Negative values fold toward the edge normal.
	 * When converting vertex weight values to edge values, the value with the smallest absolute value is selected.
	 * If a valid weight map is found with the given Weight Map name, then both Low and High values
	 * are interpolated with the per particle weight to make the final value used for the simulation.
	 * Otherwise all particles are considered to have a zero weight, and only the Low value is meaningful.
	 */
	UPROPERTY(EditAnywhere, Category = "PBDBendingElement Properties", Meta = (UIMin = "-180", UIMax = "180", ClampMin = "-180", ClampMax = "180", EditCondition = "RestAngleType == EChaosClothAssetRestAngleConstructionType::RestAngle"))
	FChaosClothAssetWeightedValueNonAnimatable RestAngle = { 0.f, 0.f, TEXT("RestAngle") };

	/**
	 * The Stiffness of the bending elements constraints. Increase the iteration count for stiffer materials.
	 * If a valid weight map is found with the given Weight Map name, then both Low and High values
	 * are interpolated with the per particle weight to make the final value used for the simulation.
	 * Otherwise all particles are considered to have a zero weight, and only the Low value is meaningful.
	 */
	UPROPERTY(EditAnywhere, Category = "PBDBendingElement Properties", Meta = (UIMin = "0", UIMax = "1", ClampMin = "0", ClampMax = "1"))
	FChaosClothAssetWeightedValue BendingElementStiffness = { true, 1.f, 1.f, TEXT("BendingElementStiffness") };

	/**
	 * Once the element has bent such that it's folded more than this ratio from its rest angle ("buckled"), switch to using Buckling Stiffness instead of BendingElement Stiffness.
	 * When Buckling Ratio = 0, the Buckling Stiffness will never be used. When BucklingRatio = 1, the Buckling Stiffness will be used as soon as its bent past its rest configuration.
	 */
	UPROPERTY(EditAnywhere, Category = "PBDBendingElement Properties", Meta = (UIMin = "0", UIMax = "1", ClampMin = "0", ClampMax = "1"))
	float BucklingRatio = 0.5f;

	/**
	 * The stiffness after buckling.
	 * The constraint will use this stiffness instead of element Stiffness once the cloth has buckled, i.e., bent beyond a certain angle.
	 * Typically, Buckling Stiffness is set to be less than BendingElement Stiffness.
	 * Buckling Ratio determines the switch point between using BendingElement Stiffness and Buckling Stiffness.
	 * If a valid weight map is found with the given Weight Map name, then both Low and High values
	 * are interpolated with the per particle weight to make the final value used for the simulation.
	 * Otherwise all particles are considered to have a zero weight, and only the Low value is meaningful.
	 */
	UPROPERTY(EditAnywhere, Category = "PBDBendingElement Properties", Meta = (UIMin = "0", UIMax = "1", ClampMin = "0", ClampMax = "1", EditCondition = "BucklingRatio != 0"))
	FChaosClothAssetWeightedValue BucklingStiffness = { true, 0.9f, 0.9f, TEXT("BucklingStiffness") };

	FChaosClothAssetSimulationPBDBendingElementConfigNode(const UE::Dataflow::FNodeParameters& InParam, FGuid InGuid = FGuid::NewGuid());

private:
	virtual void AddProperties(FPropertyHelper& PropertyHelper) const override;
};