Is this a good OO design?

Question

I'm building an API for myself to do 2D skeletal animation.

I have a Bone class and a Skeleton class.

The Skeleton creates a root bone and then subsequent bones are added via the Skeleton's add method by providing the parent bone.

What I now want to do is add animation and frames.

What I was thinking of, is a class that can load and interpolate animations. So it would be an object that would load an animation. It would then, at each frame, take in a Skeleton and modify the Skeleton accordingly.

Is this a good design? Should an animation take in a Skeleton, or should a Skeleton take in an animation and apply it onto itself?

Answer 1

It's best to create an Animation that makes use of a Skeleton instead of the opposite. This because, logically speaking, the object Skeleton does not require an Animation to live, but an Animation strongly requires a Skeleton. So you can couple those elements in the Animation itself. Do not put too much logics in the objects, and try to put it just where necessary.