RE: [GD-General] Multiple Inheritance and RTTI

[Gareth L. <GL...@cl...>]

>
> > Every frame we quickly cull out any scene nodes that are not visible
> > from a camera, and then for each scene node we query to see if they
> > implement the IRenderable interface.  If they do, they get a render
> > call.
> 
> Yes, I envisioned something like that.
> 
> What are the advantages of this approach over just providing 
> a (possibly
> empty) render() in every node type? A virtual call can never 
> lose to a QI +
> test + potential call.

It depends on the number of functions you have in the base class. If it's
just Render then sure, that's fine. But if you have 4 or 5 functions in each
interface and say 20 interfaces in the system ( with an average of 2-3 per
concrete object ) that would end up as 100 pure virtual functions, which
starts to get messy.