I told myself I would stop trolling here so much but I give in.
Normally, you do not do any sort of logic in the rendering thread. That is to say, you do not care about delta or anything like that. For animation rendering, you would set which frame is to be render in your logic (update). Then when rendering comes, you render is. If this code is working fine for you, use it but do not try measuring delta time stuff in renderloop.
Here is how I do animations or any form of timing. (no interpolation)
int currentUpdate = 0;
int frameRate = 60;
currentUpdate *= delta;
if(currentUpdate >= frameRate)
currentUpdate = 0;
This is just some psudo code. It will not take into account huge deltas but the key is to keep logic away from rendering.