function squaredLength$3(a) {
    var x = a[0];
    var y = a[1];
    var z = a[2];
    var w = a[3];
    return x * x + y * y + z * z + w * w;
  }
Calculates the squared length of a vec4

@param {ReadonlyVec4} a vector to calculate squared length of
@returns {Number} squared length of a