async function doTween(runtime)
{
// Get a Sprite instance with the Tween behavior
const inst = runtime.objects.Sprite.getFirstInstance();
// Create a tween that moves it to (300, 300) over 2 seconds
const tween = inst.behaviors.Tween.startTween("position", [300, 300], 2, "in-out-sine");
// Wait for the tween to finish
await tween.finished;
// Log to the console now the tween has finished
console.log("Tween finished");
}
More examples
Some examples of valid calls to startTween are shown below (assuming Tween represents this behavior).
// Tween X position to 300 over 2 seconds linearly
Tween.startTween("x", 300, 2, "linear");
// Tween position to (300, 300) over 2 seconds with ease "in-out-sine"
Tween.startTween("position", [300, 300], 2, "in-out-sine");
// Looping ping-pong tween to size 200x200 every 0.5 seconds
Tween.startTween("size", [200, 200], 0.5, "out-sine", {
loop: true,
pingPong: true
});
// Tween color to blue over 1.5 seconds linearly
Tween.startTween("color", [0, 0, 1], 1.5, "linear");
// Value tween from 100 to 200 linearly over 3 seconds
const t = Tween.startTween("value", 200, 3, "linear", {
startValue: 100
});
// (then read t.value over time)
Tween properties
When using the startTween method, the prop parameter must be one of the strings given in the table below. Each property also lists how many values are expected for the endValue parameter; if more than 1, they should be passed as an array.
| Property |
Number of values |
"x" |
1 |
"y" |
1 |
"position" |
2 |
"width" |
1 |
"height" |
1 |
"x-scale" |
1 |
"y-scale" |
1 |
"size" |
2 |
"scale" |
2 |
"angle" |
1 (in radians) |
"opacity" |
1 (in 0-1 range) |
"color" |
3 (RGB values in 0-1 range) |
"z-elevation" |
1 |
"value" |
1 |
Ease names
When using the startTween method, the ease parameter must be one of the strings given in the table below, or the name of a custom ease in the project.
"linear" |
|
|
"in-sine" |
"out-sine" |
"in-out-sine" |
"in-elastic" |
"out-elastic" |
"in-out-elastic" |
"in-back" |
"out-back" |
"in-out-back" |
"in-bounce" |
"out-bounce" |
"in-out-bounce" |
"in-cubic" |
"out-cubic" |
"in-out-cubic" |
"in-quadratic" |
"out-quadratic" |
"in-out-quadratic" |
"in-quartic" |
"out-quartic" |
"in-out-quartic" |
"in-quintic" |
"out-quintic" |
"in-out-quintic" |
"in-circular" |
"out-circular" |
"in-out-circular" |
"in-exponential" |
"out-exponential" |
"in-out-exponential" |
Tween behavior APIs
- startTween(prop, endValue, time, ease, opts)
- Start a tween running for a property to a given end value, over a
time given in seconds, with an ease function specified by ease. Returns an ITweenState representing the running tween.
prop must be a string of one of the property names given in the table in the section Tween properties above.
endValue must be either a number, or an array of numbers, depending on prop. In the table of properties above, where the Number of values is 1, this must be a number; where it is greater than 1, it must be an array with that many values.
time is the duration the tween will run for in seconds.
ease is a string of the name of one of the built-in eases in the section Ease names above, or the name of a custom ease in the project.
The opts parameter is optional for providing further parameters via object properties. The following properties can be used:
tags: a list of tags to assign to the tween, specified either as a space-separated string, or an array of strings
destroyOnComplete: a boolean indicating whether to automatically destroy the instance once the tween completes (default false)
loop: a boolean indicating whether to repeat the tween when it reaches the end (default false)
repeatCount: the number of times to repeat the tween (default 1).
pingPong: a boolean indicating whether to alternate the playback direction when repeating (default false)
startValue: for value tweens only, specifies the start value (default 0).
See above for some code examples demonstrating some of the ways this method can be called.
- *allTweens()
- Iterates all actively running tweens created by the behavior, represented with ITweenState.
- *tweensByTags(tags)
- Iterates all actively running tweens matching the given set of tags, represented with ITweenState. The tags may be specified as either a space-separated string, or an array of strings.
- isEnabled
- A boolean indicating if the behavior is enabled. If disabled, the behavior no longer has any effect on the object.