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jeremyckahn / shifty

The fastest TypeScript animation engine on the web
https://jeremyckahn.github.io/shifty/doc/
MIT License
1.54k stars 87 forks source link

Add #hasEnded() #151

Closed arthuro555 closed 2 years ago

arthuro555 commented 2 years ago

Adds a way to check whether the tweenable has finished tweening or not.

jeremyckahn commented 2 years ago

Thank you for the PR @arthuro555! I should have time to review in the next day or so.

jeremyckahn commented 2 years ago

This is has been released in v2.18.0!

arthuro555 commented 2 years ago

Out of curiosity, what's your use case for this method?

It's for usage in GDevelop. The events loop is separate from the JavaScript one and shouldn't be deeply coupled to JavaScript features, as we have a modular architecture where we could technically swap out the runtime engine's language at any time, and the event loop should work exactly the same independently of the runtime implementation language. Therefore, our events loop cannot really use JavaScript async/await or callbacks directly - instead, we do what the JavaScript event loop would do, check at every update of the loop if the state of the events' target is in a state where the event should be triggered.

Usually we just use an extra variable that we set to true when a callback is called, and use that variable to know whether to trigger events or not, but that is annoying, bloats our code, adds a variable & a callback that are redundant, is error prone... Therefore, it is more convenient and performant for us to have a way to check if the state of the object (in this case the tweenable) is in a state where it should trigger an event (in this case "the tween is complete" event), instead of having to set a callback on it (in this case via Tweenable#then).

jeremyckahn commented 2 years ago

That makes a lot of sense. I think that's how a number of other engines such as RPG Maker MV work as well.

It's exciting to see GDevelop mature as a game engine to this degree! 😁