         adjustToFitPath()
     }
 
-    /// Returns the receiver's center. Animatable.
+    /// The center point (top-left) of the receiver's frame. Animatable.
+    ///
+    /// - returns: A C4Point, the receiver's center.
     public override var center : C4Point {
         get {
             return C4Point(view.center)

    /// let l = C4Line((a,b))
    /// ````
    ///
    /// - parameter points: An tuple of C4Point structs.
    convenience public init(_ points: (C4Point, C4Point)) {
        self.init(frame: C4Rect(points))
        let path = C4Path()

        }
    }

    /// The origin point (top-left) of the receiver's frame. Animatable.
    ///
    /// - returns: A C4Point, the receiver's origin.
    public override var origin : C4Point {
        get {
            return C4Point(view.frame.origin)
