typed-array-interleave/index.js

Interleave n typed arrays.

/**
 * @module typedArrayInterleave
 */

/**
 * Interleave n typed arrays
 *
 * @alias module:typedArrayInterleave
 * @param {TypedArray} ResultConstructor Returned typed array constructor
 * @param {Array} elements Number of elements to group for each typed array
 * @param {...TypedArray} arrays Arrays to interleave
 * @returns {TypedArray}
 */
function typedArrayInterleave(ResultConstructor, elements, ...arrays) {
  const totalLength = arrays.reduce((total, arr) => total + arr.length, 0);
  const result = new ResultConstructor(totalLength);
  const stride = elements.reduce((a, b) => a + b);

  for (let i = 0; i < totalLength; i++) {
    let offset = 0;
    for (let j = 0; j < elements.length; j++) {
      for (let k = 0; k < elements[j]; k++) {
        result[i * stride + offset] = arrays[j][elements[j] * i + k];
        offset++;
      }
    }
  }

  return result;
}

export default typedArrayInterleave;