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This chapter shows you how to get the Time and use Timers.

To read time you can use the functions from:

import Mischief.ECS.Time qualified as Time

The most important one is delta, which gets you the time that has passed since the last frame, in seconds.

d <- Time.delta

You can also use Time.time to get the actual Time:

t <- Time.time

Time has two fields: .elapsed and .delta. Both contain a TimeSpec.

You can convert a TimeSpec to seconds using specToSecs:

let elapsed = Time.specToSecs t.elapsed
let delta = Time.specToSecs t.delta

A Timer is a data type that can keep track of time and be ticked down each frame.

import Mischief.ECS.Timer qualified as Timer

There are two modes for a timer. A Repeat timer will infinitely loop around once it finished, while an Once timer stops after finishing once.

To create a timer you must give it a duration and a mode:

let timer = Timer.new 0.5 Timer.Repeat

The tick function takes an amount of time (typically obtained from Time.delta) and returns a new timer, along with a bool specifying whether it just finished or not:

delta <- Time.delta
let (timer', justFinished) <- Timer.tick delta timer