update method

[martindrapeau]

I've been using methods remove and add to perform an update. The use case for this is when an object has moved (i.e. a sprite changes position). Would be nice to have an optimized update method.

[asaarinen]

Thanks for your contribution. At least we could have an update method just wrapping add and remove.

A general update method would have to traverse the entire tree anyway to insert the updated object into correct location, which is no better than add and remove. Maybe simply check whether the object has moved out of its current node and add/remove it only in case it has.

However as the quadtree stores the very same objects whose coordinates we are modifying, the update method would need to get the updated coordinates as a separate argument and apply those changes.