Repeat broken after first iteration

[djeedai]

Run any example (except menu currently broken due to #41) : the color animation goes from red to blue smoothly during the first loop, then from the second loop ping-pongs between full red and full blue without any interpolation.

@SUPERCILEX this is probably due to a bug in #19.

This is blocking #34

[SUPERCILEX]

This isn't an issue in #38 so let's try to get that through. Probs one of the things I said would be broken in the intermediary, but lemme try and find the bug real quick to confirm.

[SUPERCILEX]

Yeah, it's because progress is no longer bound to the 0,1 range and instead keeps increasing forever.