Hash.js

import { Fn } from '../tsl/TSLBase.js';
import { uint } from '../tsl/TSLCore.js';

/**
 * Generates a hash value in the range `[0, 1]` from the given seed.
 *
 * @tsl
 * @function
 * @param {Node<float>} seed - The seed.
 * @return {Node<float>} The hash value.
 */
export const hash = /*@__PURE__*/ Fn( ( [ seed ] ) => {

	// Taken from https://www.shadertoy.com/view/XlGcRh, originally from pcg-random.org

	const state = seed.toUint().mul( uint( 747796405 ) ).add( uint( 2891336453 ) );
	const word = state.shiftRight( state.shiftRight( 28 ).add( 4 ) ).bitXor( state ).mul( uint( 277803737 ) );
	const result = word.shiftRight( 22 ).bitXor( word );

	return result.toFloat().mul( 1 / 2 ** 32 ); // Convert to range [0, 1)

} );