This is a rough prototype of a game mechanic I wanted to try implementing: a realtime rewind mechanic.

To achieve this, the physical states of the game objects and the player are saved regularly in memory. When rewinding, it is then just a matter of reapplying the states accordingly. To have a smooth rewind animation, a linear interpolation is applied between these states.

To reduce the memory usage, those states aren’t saved at a regular interval, but are instead saved when the physical value changes reach a variable threshold. This allows to compress the information by only saving states when a value change is relevant.