@woosh/meep-engine/src/core/primitives/numbers/computeHashFloat.js

Pure JavaScript game engine. Fully featured and production ready.

import { UINT32_MAX } from "../../binary/UINT32_MAX.js";

/**
 *
 * @param {number} v
 * @returns {number}
 */
export function computeHashFloat(v) {
    // we break the number up into fractional and whole parts
    const whole = v >> 0;

    const fraction = v - whole;

    // fractional part is scaled up into uint32 range,
    // this inexact method, as it will produce 0 hash for values below a certain threshold, but it's fast
    const fraction_hash = ((fraction) * UINT32_MAX) >>> 0;

    // we flip the order, tiny fractions will result in higher bits of the final hash, leads to better dispersion
    const fraction_hash_inverse = UINT32_MAX - fraction_hash;

    // take XOR of both parts
    return fraction_hash_inverse ^ whole;
}