FFT< fftSize > Class Template Reference

A templated class for performing Fast Fourier Transform (FFT) operations. More...

#include <FFT.h>

Static Public Member Functions
static void	Radix2FFT (float *data)
	Performs a Radix-2 FFT on the provided data.
static void	ComplexMagnitude (float *complexData, float *magnitude)
	Computes the magnitude of complex numbers from interleaved real and imaginary components.

Static Private Member Functions
static constexpr int	CalculateBits (int size, int count=0)
	Calculates the number of bits required for bit reversal based on FFT size.
static void	BitReverseOrder (float *data)
	Reorders the data array in bit-reversed order.
static int	ReverseBits (int num)
	Reverses the bits of an integer.
static void	Swap (float *a, float *b)
	Swaps two floating-point values.

Static Private Attributes
static const constexpr float	twiddleCoefficients [fftSize *2]
	Precomputed twiddle coefficients for the FFT.
static const constexpr int	bitCount = CalculateBits(fftSize)
	The number of bits needed for bit reversal for this FFT size.

Detailed Description

template<int fftSize>
class FFT< fftSize >

A templated class for performing Fast Fourier Transform (FFT) operations.

Template Parameters

fftSize

The size of the FFT, must be a power of 2.

Definition at line 20 of file FFT.h.

Member Function Documentation

BitReverseOrder()

template<int fftSize>

static void BitReverseOrder ( float *  data )

staticprivate

Reorders the data array in bit-reversed order.

Parameters

data	The data array to reorder.

CalculateBits()

template<int fftSize>

static constexpr int CalculateBits ( int  size, int  count = 0  )

staticconstexprprivate

Calculates the number of bits required for bit reversal based on FFT size.

Parameters

size	The FFT size.
count	Recursive parameter to count the bits.

Returns

The number of bits required.

ComplexMagnitude()

template<int fftSize>

static void ComplexMagnitude ( float *  complexData, float *  magnitude  )

static

Computes the magnitude of complex numbers from interleaved real and imaginary components.

Parameters

complexData	The input array containing interleaved real and imaginary components.
magnitude	The output array for storing computed magnitudes.

Referenced by MicrophoneFourier::Update(), and MicrophoneFourier::UpdateDMA().

Radix2FFT()

template<int fftSize>

static void Radix2FFT ( float *  data )

static

Performs a Radix-2 FFT on the provided data.

Parameters

data	The input array containing interleaved real and imaginary components.

Referenced by MicrophoneFourier::Update(), and MicrophoneFourier::UpdateDMA().

ReverseBits()

template<int fftSize>

static int ReverseBits ( int  num )

staticprivate

Reverses the bits of an integer.

Parameters

num	The number whose bits are to be reversed.

Returns

The bit-reversed integer.

Swap()

template<int fftSize>

static void Swap ( float *  a, float *  b  )

staticprivate

Swaps two floating-point values.

Parameters

a	Pointer to the first value.
b	Pointer to the second value.

Member Data Documentation

bitCount

template<int fftSize>

const constexpr int bitCount = CalculateBits(fftSize)

staticconstexprprivate

The number of bits needed for bit reversal for this FFT size.

Definition at line 46 of file FFT.h.

twiddleCoefficients

template<int fftSize>

const constexpr float twiddleCoefficients[fftSize *2]

staticconstexprprivate

Initial value:

= [] {
        float temp[fftSize * 2];
 
        for (int i = 0; i < fftSize * 2; ++i) {
            temp[i] = FFT<fftSize>::calculateCoefficient(i);
        }
 
        return temp;
    }()

Precomputed twiddle coefficients for the FFT.

Definition at line 25 of file FFT.h.

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The documentation for this class was generated from the following file:

• FFT.h