FFTAlgorithm.h

Go to the documentation of this file.

// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "CoreMinimal.h"
#include "Features/IModularFeature.h"
 
namespace Audio
{
    enum class EFFTScaling : uint8
    {
        None,
 
        MultipliedByFFTSize,
 
        MultipliedBySqrtFFTSize,
 
        DividedByFFTSize,
 
        DividedBySqrtFFTSize,
    };
 
    struct FFFTSettings
    {
        int32 Log2Size;
 
        bool bArrays128BitAligned;
 
        bool bEnableHardwareAcceleration;
    };
 
    class IFFTAlgorithm 
    {
        public:
            SIGNALPROCESSING_API virtual ~IFFTAlgorithm();
 
            virtual int32 Size() const = 0;
 
            int32 NumInputFloats() const { return Size(); };
 
            int32 NumOutputFloats() const { return Size() + 2; }
 
            virtual EFFTScaling ForwardScaling() const = 0;
 
            virtual EFFTScaling InverseScaling() const = 0;
 
            
            virtual void ForwardRealToComplex(const float* RESTRICT InReal, float* RESTRICT OutComplex) = 0;
 
            virtual void InverseComplexToReal(const float* RESTRICT InComplex, float* RESTRICT OutReal) = 0;
 
            virtual void BatchForwardRealToComplex(int32 InCount, const float* const RESTRICT InReal[], float* RESTRICT OutComplex[]) = 0;
 
            virtual void BatchInverseComplexToReal(int32 InCount, const float* const RESTRICT InComplex[], float* RESTRICT OutReal[]) = 0;
    };
 
    class IFFTAlgorithmFactory : public IModularFeature
    {
        public:
            virtual ~IFFTAlgorithmFactory()
            {}
 
            static SIGNALPROCESSING_API const FName GetModularFeatureName();
 
            virtual FName GetFactoryName() const = 0;
 
            virtual bool IsHardwareAccelerated() const = 0;
 
            virtual bool Expects128BitAlignedArrays() const = 0;
 
            virtual bool AreFFTSettingsSupported(const FFFTSettings& InSettings) const = 0;
 
            virtual TUniquePtr<IFFTAlgorithm> NewFFTAlgorithm(const FFFTSettings& InSettings) = 0;
    };
 
    class FFFTFactory
    {
        public:
            static SIGNALPROCESSING_API const FName AnyAlgorithmFactory;
 
            static SIGNALPROCESSING_API TUniquePtr<IFFTAlgorithm> NewFFTAlgorithm(const FFFTSettings& InSettings, const FName& InAlgorithmFactoryName = AnyAlgorithmFactory);
 
            static SIGNALPROCESSING_API bool AreFFTSettingsSupported(const FFFTSettings& InSettings, const FName& InAlgorithmFactoryName = AnyAlgorithmFactory);
    };
}