Godot's built-in Timer node is a powerful tool for creating timed events in your games. Whether you need to implement delays, create repeating actions, or manage game mechanics based on time, understanding how to start, stop, and reset the Timer is crucial. This guide will walk you through the process, providing clear examples and explanations.
Understanding the Godot Timer Node
The Timer node is a simple yet versatile node in Godot's scene system. It has a single important property: wait_time, which specifies the time (in seconds) before the timeout signal is emitted. This signal is the core of the Timer's functionality; you connect scripts to this signal to trigger actions at specific intervals.
Key Properties and Signals
wait_time: This float value determines the time interval betweentimeoutsignals. A value of 0 means the timer will emit the signal immediately upon starting.autostart: A boolean value. Iftrue, the timer begins immediately upon entering the scene. Otherwise, you'll need to start it manually.one_shot: A boolean value. Iftrue, the timer emits thetimeoutsignal only once. Iffalse, it repeatedly emits the signal at thewait_timeinterval.timeout: This signal is emitted when the timer reaches itswait_time. This is where you'll place your game logic.
Starting the Timer
There are several ways to start a Timer node in Godot:
-
Using
autostart: Set theautostartproperty totruein the Godot editor. This will automatically start the timer when the scene is loaded. This is convenient for simple, self-contained timers. -
Programmatically using
start(): Ifautostartisfalse(the default), you can start the timer using thestart()method in your GDScript. This provides more control, allowing you to start the timer based on game events.
# Example in GDScript
func _ready():
# Assuming 'timer' is your Timer node
$Timer.start()
Stopping the Timer
To halt a running timer, use the stop() method:
func _on_something_happened():
$Timer.stop()
This will immediately pause the timer. The remaining time until the next timeout signal will be lost.
Resetting the Timer
Resetting a timer means stopping it and then restarting it. This ensures it starts counting from the beginning. You can achieve this by combining stop() and start():
func _on_reset_button_pressed():
$Timer.stop()
$Timer.start()
Alternatively, you could use the set_wait_time function along with start() to reset the time to a specific value.
Example: Simple Countdown Timer
Let's create a simple countdown timer that counts down from 10 seconds and then prints a message:
extends Node2D
# This assumes you have a Timer node named "Timer" as a child of this node.
onready var timer = $Timer
func _ready():
timer.wait_time = 10
timer.one_shot = true # Only trigger once
timer.connect("timeout", self, "_on_timer_timeout")
timer.start()
func _on_timer_timeout():
print("Time's up!")
This script sets up a timer to trigger once after 10 seconds. The _on_timer_timeout function will then be called, printing "Time's up!" to the console.
Advanced Usage: Repeating Timers and More
For repeating timers, set the one_shot property to false. The timeout signal will then be emitted repeatedly at intervals defined by wait_time. This is useful for tasks such as updating game logic periodically or creating animations. Remember to handle potential issues like accidentally starting a timer multiple times.
By mastering the start(), stop(), and reset() functions in conjunction with the Timer node's properties, you can effectively manage time-based events and create dynamic and engaging game experiences in Godot. Remember to adjust the wait time and one_shot variables as needed for your particular use case.
