ReadonlyafterFire callback once, seconds of game time from now. A non-positive
seconds fires on the next advance.
ReadonlyeveryFire callback every seconds of game time, repeatedly. seconds must
be > 0. If a single advance spans multiple intervals, the callback
fires once per elapsed interval (catch-up), preserving the remainder.
ReadonlyadvanceAdvance every active timer by dt seconds, firing those that come due (in
scheduule order). Timers created during an advance wait for the next one.
ReadonlycancelCancel every timer.
ReadonlycountNumber of currently-active timers.
A pool of game-time timers. Drive it with Timers.advance.