clamp( min, max ) {

		// assumes min < max, componentwise

		this.x = clamp( this.x, min.x, max.x );
		this.y = clamp( this.y, min.y, max.y );
		this.z = clamp( this.z, min.z, max.z );
		this.w = clamp( this.w, min.w, max.w );

		return this;

	}
If this vector's x, y, z or w value is greater than the max vector's x, y, z or w
value, it is replaced by the corresponding value.
If this vector's x, y, z or w value is less than the min vector's x, y, z or w value,
it is replaced by the corresponding value.

@param {Vector4} min - The minimum x, y and z values.
@param {Vector4} max - The maximum x, y and z values in the desired range.
@return {Vector4} A reference to this vector.