Game Loop (note that extraneous details were omitted) -> http://pastebin.com/BHe0C3nK
I've been brainstorming some game loop designs and this is one that seems somewhat standard based on what I've read, but there are some implementation questions that I haven't completely answered myself yet (which is why I'm posting here).
The problem mostly lies with the rendering interpolation. Say for example, you're between t = 1 and t = 2. You need to render the scene at t = 1.5 so your interpolation value is 0.5. If you're using physics for your objects, this is simple. If you aren't, then you can save the previous positions, scales, and rotations and approximate where they'll be at when t = 1.5. This is fine as long as you're rendering every object in existence. However, in the case where you're culling some objects (which you should be), you really don't want to waste processing time on caching data that you won't use because the object isn't even being rendered.
So what's a reasonable solution here? Perhaps a flag can be used per object to determine whether or not it was rendered (and therefore had its position/scale/rotation data cached) last frame? Are there other improvements or even simplifications that can be made to the game loop? How is your game loop implemented?