Time scales in Oolite

When writing scripts or shaders for Oolite, there are several different time scales to consider. This article defines them and provides nomenclature to simplify discussions where the distinctions matter.

Player real time

This is the time frame of the human being playing the game. By definition, it advances at a rate of one player real time second per real-world second.

Game real time

This is the time frame of the game simulation. Assuming a properly-functioning computer, it runs at one game real time second per player real time second, except when the game is paused, at which time it is suspended. However, it can be run at different rates using the time acceleration factor testing facility. This is the time frame that’s generally relevant to shaders and AIs.

Game clock time

This is the time displayed on the clock on the HUD. It normally runs at a rate of one game clock time second per game real time second. However, some in-game events take a significant amount of clock time without providing an opportunity for gameplay; examples include witchspace jumps, docking and loading cargo. When such an event occurs, the HUD clock shows the label “adjusting” and runs faster than game real time. This time frame is relevant to missions with a time limit.