module.exports = fromMat4

/**
 * Copies the upper-left 3x3 values into the given mat3.
 *
 * @alias mat3.fromMat4
 * @param {mat3} out the receiving 3x3 matrix
 * @param {mat4} a   the source 4x4 matrix
 * @returns {mat3} out
 */
function fromMat4(out, a) {
  out[0] = a[0]
  out[1] = a[1]
  out[2] = a[2]
  out[3] = a[4]
  out[4] = a[5]
  out[5] = a[6]
  out[6] = a[8]
  out[7] = a[9]
  out[8] = a[10]
  return out
}