node_modules/three/src/nodes/procedural/Checker.js

import { uv } from '../accessors/UV.js';
import { Fn } from '../tsl/TSLBase.js';

/**
 * Creates a 2x2 checkerboard pattern that can be used as procedural texture data.
 *
 * @tsl
 * @function
 * @param {Node<vec2>} coord - The uv coordinates.
 * @return {Node<float>} The result data.
 */
export const checker = /*@__PURE__*/ Fn( ( [ coord = uv() ] ) => {

	const uv = coord.mul( 2.0 );

	const cx = uv.x.floor();
	const cy = uv.y.floor();
	const result = cx.add( cy ).mod( 2.0 );

	return result.sign();

} );