function multiplyScalar(out, a, b) {
    out[0] = a[0] * b;
    out[1] = a[1] * b;
    out[2] = a[2] * b;
    out[3] = a[3] * b;
    out[4] = a[4] * b;
    out[5] = a[5] * b;
    out[6] = a[6] * b;
    out[7] = a[7] * b;
    out[8] = a[8] * b;
    out[9] = a[9] * b;
    out[10] = a[10] * b;
    out[11] = a[11] * b;
    out[12] = a[12] * b;
    out[13] = a[13] * b;
    out[14] = a[14] * b;
    out[15] = a[15] * b;
    return out;
  }
Multiply each element of the matrix by a scalar.

@param {mat4} out the receiving matrix
@param {ReadonlyMat4} a the matrix to scale
@param {Number} b amount to scale the matrix's elements by
@returns {mat4} out