Attenuation.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "CoreMinimal.h"
#include "UObject/ObjectMacros.h"
#include "UObject/Object.h"
#include "UObject/Class.h"
#include "Engine/EngineTypes.h"
#include "Curves/CurveFloat.h"
#include "Attenuation.generated.h"
 
struct FGlobalFocusSettings;
 
UENUM(BlueprintType)
enum class EAttenuationDistanceModel : uint8
{
    Linear,
    Logarithmic,
    Inverse,
    LogReverse,
    NaturalSound,
    Custom,
};
 
UENUM(BlueprintType)
namespace EAttenuationShape
{
    enum Type : int
    {
        Sphere,
        Capsule,
        Box,
        Cone
    };
}
 
UENUM(BlueprintType)
enum class ENaturalSoundFalloffMode : uint8
{
    // (Default) Continues attenuating pass falloff max using volume value
    // specified at the max falloff distance's bounds
    Continues,
 
    // Sound goes silent upon leaving the shape
    Silent,
 
    // Holds the volume value specified at the shapes falloff bounds
    Hold,
};
 
/*
* Base class for attenuation settings.
*/
USTRUCT(BlueprintType)
struct FBaseAttenuationSettings
{
    GENERATED_USTRUCT_BODY()
 
    ENGINE_API virtual ~FBaseAttenuationSettings();
 
    /* The type of attenuation as a function of distance to use. */
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category= AttenuationDistance, meta = (DisplayName = "Attenuation Function"))
    EAttenuationDistanceModel DistanceAlgorithm;
 
    /* The shape of the non-custom attenuation method. */
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category= AttenuationDistance)
    TEnumAsByte<enum EAttenuationShape::Type> AttenuationShape;
 
    // Whether to continue attenuating, go silent, or hold last volume value when beyond falloff bounds and 
    // 'Attenuation At Max (dB)' is set to a value greater than -60dB.
    // (Only for 'Natural Sound' Distance Algorithm). */
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category= AttenuationDistance)
    ENaturalSoundFalloffMode FalloffMode;
 
    /* The attenuation volume at the falloff distance in decibels (Only for 'Natural Sound' Distance Algorithm). */
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category= AttenuationDistance, meta=(DisplayName = "Attenuation At Max (dB)", ClampMin = "-60", ClampMax = "0"))
    float dBAttenuationAtMax;
 
    /* The dimensions to use for the attenuation shape. Interpretation of the values differ per shape.
       Sphere  - X is Sphere Radius. Y and Z are unused
       Capsule - X is Capsule Half Height, Y is Capsule Radius, Z is unused
       Box     - X, Y, and Z are the Box's dimensions
       Cone    - X is Cone Radius, Y is Cone Angle, Z is Cone Falloff Angle
    */
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category= AttenuationDistance)
    FVector AttenuationShapeExtents;
 
    /* The distance back from the sound's origin to begin the cone when using the cone attenuation shape. */
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category= AttenuationDistance, meta=(ClampMin = "0"))
    float ConeOffset;
 
    /* The distance over which volume attenuation occurs. */
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category= AttenuationDistance, meta=(ClampMin = "0"))
    float FalloffDistance;
 
    /* An optional attenuation radius (sphere) that extends from the cone origin. */
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = AttenuationDistance, meta = (ClampMin = "0"))
    float ConeSphereRadius;
 
    /* The distance over which volume attenuation occurs for the optional sphere shape. */
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = AttenuationDistance, meta = (ClampMin = "0"))
    float ConeSphereFalloffDistance;
 
    /* The custom volume attenuation curve to use. Value clamped at 1.0. */
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category= AttenuationDistance)
    FRuntimeFloatCurve CustomAttenuationCurve;
 
    ENGINE_API FBaseAttenuationSettings();
 
    struct AttenuationShapeDetails
    {
        FVector Extents;
        float Falloff;
        float ConeOffset;
        float ConeSphereRadius;
        float ConeSphereFalloff;
    };
 
    ENGINE_API virtual void CollectAttenuationShapesForVisualization(TMultiMap<EAttenuationShape::Type, AttenuationShapeDetails>& ShapeDetailsMap) const;
    ENGINE_API float GetMaxDimension() const;
 
    ENGINE_API float GetMaxFalloffDistance() const;
 
    ENGINE_API float Evaluate(const FTransform& Origin, FVector Location, float DistanceScale = 1.f) const;
 
    ENGINE_API float AttenuationEval(float Distance, float Falloff, float DistanceScale = 1.f) const;
    ENGINE_API float AttenuationEvalBox(const FTransform& Origin, FVector Location, float DistanceScale = 1.f) const;
    ENGINE_API float AttenuationEvalCapsule(const FTransform& Origin, FVector Location, float DistanceScale = 1.f) const;
    ENGINE_API float AttenuationEvalCone(const FTransform& Origin, FVector Location, float DistanceScale = 1.f) const;
};