Timers

Timers#

With timers, you can execute events with a delay. This means an action doesn’t happen immediately, but after a specified delay in milliseconds or frames.

Timers are useful, for example, if you want something to happen after a certain amount of time.

:::{note} Python’s time library offers the function time.sleep(...) to create delays. However, you should not use it here, as it causes global pauses and may lead to unwanted side effects. :::

Starting a Timer#

To start a timer, you can use the following example:

from miniworlds import ActionTimer
[...]
ActionTimer(24, player.move)

Explanation#

  1. After 24 frames, the timer is triggered.

  2. The method player.move is then executed.

Different Timer Types#

There are different types of timers, depending on your use case:

ActionTimer#

The ActionTimer executes a method once after a set amount of time, then removes itself automatically. It’s ideal for one-time delayed actions.

ActionTimer(24, player.move, None)

In this example, the move function of the player object is executed once after 24 frames.

LoopActionTimer#

The LoopActionTimer works similarly to the ActionTimer but repeats the action at regular intervals. It’s ideal for actions that should occur continuously.

LoopActionTimer(24, player.move)

Here, the move method of the player will be executed every 24 frames.

To stop a LoopActionTimer, you can unregister it:

loopactiontimer = LoopActionTimer(24, player.move)
...
loopactiontimer.unregister()  # Stops the LoopActionTimer

Linking Timers to Events#

Just like with sensors, you can configure timers to trigger methods at specific times. To do this, register methods that should be executed on a timer event.

Example of a one-time timer event:

@timer(frames=24)
def moving():
    player.move()

In this case, the moving function is executed once after 24 frames, triggering player.move().

To register a looping timer that repeats regularly, use:

@loop(frames=48)
def moving():
    player.turn_left()
    player.move(2)

Here, the moving method is called every 48 frames, turning the actor left and moving it forward.

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