bidirectional connection animation

[alixander]

Right now animated: true does nothing to connections where it's double-ended

• --
• <->

The animation can bounce back and forth in these cases.

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Context:

[bo-ku-ra]

#654

[danielsuh05]

Hello! I'm interested in contributing to this project and this issue looks like something I'm able to tackle. Would it possible to be assigned to this issue? Thank you!

[alixander]

@bo-ku-ra ah, your suggestion makes sense now! Thank you for pointing out the duplicate issue too.

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@23danielsuh Yes, much appreciated!

I would start by adding a test, and then just modifying d2render/svg.

https://github.com/terrastruct/d2/blob/master/e2etests/testdata/txtar.txt.

After you add this test, you can keep running TA=1 ./ci/test.sh ./e2etests -run TestE2E/txtar/your-test-name -v to see changes and keep opening the new svg to see what it looks like.

[bo-ku-ra]

fyi

https://play.d2lang.com/?l=&script=hMxBCsJADAXQ_T9F6T5ityn0LmmTakCtTCPDMHh3Eddj1w_eJblS2vLOAwQz933NrnHlYdyj3Oy0PWXxKNydxzcWQIjm-iN5-F3ClLtIL_vyH4PCDvYVMJq0NRhNa8s-AQAA__8%3D&

[danielsuh05]

I am somewhat confused which method I should be implementing. Should I do the bouncing one mentioned in #1936 or should I do the "splitting" one mentioned in #654?
From my understanding, the bouncing one would switch between the two directions every secondish.

[bo-ku-ra]

i prefer #654 to #1936.
but my opinion may be a minority.

[alixander]

very useful proof of concept @bo-ku-ra .

@23danielsuh Let's go with the splitting one (flowing towards endpoints from middle, for both -- and <->). I think it's smoother than bouncing, especially when there are multiple bouncing at different lengths.

[bo-ku-ra]

(flowing towards endpoints from middle, for both -- and <->).

i want if possible.

style.animated: true;          #flowing towards endpoints from middle
style.animated-reverse: true;  # <- new

[danielsuh05]

@bo-ku-ra For now I'm going to focus on this task (first issue!, so don't want to be be overwhelmed with things). You're welcome to open another issue though

[alixander]

yeah that can be a separate issue down the road if needed. It's hard for me to think of when someone would want that though. Flowing towards endpoints already conveys semantics of bidirectional flow of information. Maybe purely stylistic? But I'd rather not introduce a new keyword for that unless there's a strong reason I'm not seeing.

[bo-ku-ra]

for consistency of vectors and descriptions.
not critical.
not required.

https://play.d2lang.com/?l=&script=fM9BTsQwDIXhvU_x1CVSELD0gjNwBc_Ekxi16ZA4gqrq3VFZUnVWXvySP71ULYY6fzfGKwldGINNkqwobt17VXzOVtqAtWW5K8P1xze6EglCwIWxNl9GfZZik7hGhteuG10fZ4qkR6vpXaq4zUeRFOEd8fThX76de0-MNaul7Iy3l40oUWYMH1onKVp8XKBfXcb_rlHal2TK-zH6DQAA__8%3D&

[alixander]

But if you're joining something, there's always an object in the middle. Just looks like a black hole otherwise