Bit Reversal Utilities

Bit-reversal permutation utilities for FFT algorithms.

bitReverse()

Reverses the bits of an integer.

function bitReverse(value: number, bitWidth: number): number;

Example

import { bitReverse } from 'webgpu-fft';

// Reverse 3 bits of value 1 (001 → 100)
const result = bitReverse(1, 3); // 4

log2()

Base-2 logarithm for positive power-of-two sizes.

function log2(n: number): number;

Example

import { log2 } from 'webgpu-fft';

console.log(log2(1024)); // 10

isPowerOf2()

Checks if a number is a power of 2.

function isPowerOf2(n: number): boolean;

Example

import { isPowerOf2 } from 'webgpu-fft';

console.log(isPowerOf2(1024)); // true
console.log(isPowerOf2(1000)); // false

bitReversalPermutation()

Returns a new interleaved complex array reordered by bit-reversal.

function bitReversalPermutation(data: Float32Array): Float32Array;

Example

import { bitReversalPermutation } from 'webgpu-fft';

const input = new Float32Array([0, 0, 1, 0, 2, 0, 3, 0]);
const output = bitReversalPermutation(input);
// output is [0, 0, 2, 0, 1, 0, 3, 0]

data must be interleaved complex data and must contain a power-of-two number of complex samples. Invalid input throws RangeError.

bitReversalPermutationInPlace()

Reorders an interleaved complex array in-place using bit-reversal.

function bitReversalPermutationInPlace(data: Float32Array): void;

Example

import { bitReversalPermutationInPlace } from 'webgpu-fft';

const data = new Float32Array([0, 0, 1, 0, 2, 0, 3, 0]);
bitReversalPermutationInPlace(data);
// data is now [0, 0, 2, 0, 1, 0, 3, 0]

Validation is performed before mutation. Invalid input throws RangeError and leaves the array unchanged.

Related

• 1D FFT Tutorial — FFT basics
• CPU FFT API — CPU implementation uses these utilities