Gets the x coordinate of the DisplayObject instance relative to the local coordinates of the parent DisplayObjectContainer.
If the object is inside a DisplayObjectContainer that has transformations, it is in the local coordinate system of the enclosing DisplayObjectContainer. Thus, for a DisplayObjectContainer rotated 90 degrees counterclockwise, the DisplayObjectContainer's children inherit a coordinate system that is rotated 90 degrees counterclockwise. The object's coordinates refer to the registration point position.