Arithmetic mapping function that scales a vec2 buffer array

scale-vec2-buffer-array.js

/**
 * Creates a mapping function that scales a vec2 buffer array
 *
 * @param {number} x x scale
 * @param {number} y y scale
 * @return {function} method to pass to Array.prototype.map
 *
 * @example
 *
 * [
 *   -0.5, -0.5,
 *   -0.5,  0.5,
 *    0.5, -0.5,
 *    0.5,  0.5
 * ].map(scale(2, 3))
 *
 * // [
 * //   -1, -1.5,
 * //   -1,  1.5,
 * //    1, -1.5,
 * //    1,  1.5
 * // ]
 */
const scale = (x, y) => (v, i) => v * ((i + 1) % 2 * x + i % 2 * y)