SphericalHarmonicCalculator.h

Go to the documentation of this file.

// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "HAL/UnrealMemory.h"
#include "Math/Matrix.h"
#include "Math/UnrealMathSSE.h"
#include "Math/Vector2D.h"
 
 
/*
    Azimuth angle is measured CCW from front.
    Elevation is 0 horizontal plane, + is above horizontal plane
*/
 
class FSphericalHarmonicCalculator
{
public:
    enum UE_DEPRECATED(5.7, "Not necessary, please use a raw index for ACN values") AmbiChanNumber
    {
        /* 0th-Order */ ACN_0 = 0,
        /* 1st-Order */ ACN_1, ACN_2, ACN_3,
        /* 2nd-Order */ ACN_4, ACN_5, ACN_6, ACN_7, ACN_8,
        /* 3rd-Order */ ACN_9, ACN_10, ACN_11, ACN_12, ACN_13, ACN_14, ACN_15,
        /* 4th-Order */ ACN_16, ACN_17, ACN_18, ACN_19, ACN_20, ACN_21, ACN_22, ACN_23, ACN_24,
        /* 5th-Order */ ACN_25, ACN_26, ACN_27, ACN_28, ACN_29, ACN_30, ACN_31, ACN_32, ACN_33, ACN_34, ACN_35,
    };
 
    static SIGNALPROCESSING_API void ComputeSoundfieldChannelGains(const int32 Order, const float Azimuth, const float Elevation, float* OutGains);
    static SIGNALPROCESSING_API void ComputeSoundfieldChannelGains(const int32 Order, const float Azimuth, const float Elevation, TArrayView<float> OutGains);
 
    static SIGNALPROCESSING_API void GenerateFirstOrderRotationMatrixGivenRadians(const float RotXRadians, const float RotYRadians, const float RotZRadians, FMatrix& OutMatrix);
    static SIGNALPROCESSING_API void GenerateFirstOrderRotationMatrixGivenDegrees(const float RotXDegrees, const float RotYDegrees, const float RotZDegrees, FMatrix& OutMatrix);
 
    template<typename T>
    static void AdjustUESphericalCoordinatesForAmbisonics(UE::Math::TVector2<T>& InOutVector)
    {
        InOutVector.X = -(InOutVector.X - HALF_PI);
        Swap(InOutVector.X,InOutVector.Y);
    }
    
    static int32 OrderToNumChannels(const int32 InOrder)
    {
        check(InOrder >= 0);
        return (InOrder+1) * (InOrder+1);
    }
 
    static SIGNALPROCESSING_API void NormalizeGains(TArrayView<float> Gains);
};