Add Rounded Corners

[johnny-duo]

This PR resolves issue #1523:

Simulator.Screen.Recording.-.iPhone.14.Pro.-.2022-11-02.at.12.09.03.mp4

[calda]

Thank you very much for working on this!

When the implementation is done and ready for review, could you also add a test case for this to the regression suite? You'll just need to:

1. add the animation json file to the Tests/Samples, ideally as Tests/Samples/Issues/issue_1523.json
2. run the unit test target, either in Xcode or by running bundle exec rake test:package

The code will also need to be formatted according to Airbnb's Swift Style Guide. You can do this automatically by running bundle exec rake format:swift.

Thanks!

[calda]

I also see you've only implemented this feature for the Main Thread rendering engine and not the new Core Animation rendering engine. That's fine for this PR -- I'll port this to the Core Animation rendering engine in a follow-up.

[johnny-duo]

@calda Hi! Thanks for looking at this PR! I'm having some issues with snapshot tests in LottieFiles/gradient_shapes and TypeFace/Apostrophe. It looks like they have "ty": "rd" inside of the jsons so I think this is expected.

Is it possible to view the Snapshot results?

[johnny-duo]

Yup! This PR is only for the main thread engine for now.

[calda]

You work at Duolingo? Cool!

I have a 1083 day streak learning Spanish 😄 Really love what Duolingo has been doing with Lottie lately -- cutting edge stuff. The new feature where the characters lip-sync with the text-to-speech synth honestly blew my mind. Is that using Lottie or some sort of custom lip sync renderer?

[johnny-duo]

Yeah! Glad you're enjoying that! I implemented that on iOS actually :D. We couldn't figure out a way to do that with Lottie so we ended up having to use a different more state-machine based animation Library

[calda]

So cool, awesome work! (Not surprised that isn't possible with Lottie)

Are you on Twitter? Would love to give you a follow if so -- I'm https://twitter.com/calstephens98

[johnny-duo]

I don't use it much for work-related stuff but gave you a follow!

[calda]

Is it possible to view the Snapshot results?

Yes, there are a few ways to do this:

1. Run the snapshot tests in Xcode. The snapshots are added as attachments to the test results in the Test navigator.
2. Add isRecording = true to the top of testMainThreadRenderingEngine in SnapshotTests.swift and re-run the tests. This updates the on-disk snapshots (which you'll need to do to make the tests pass, if this affects existing animations).

[calda]

Thank you for implementing this algorithm in Swift!

[calda]

Thank you!