[GSoC'21] Different morphing modes

[Sov-trotter]

PR Checklist

If you are contributing to Javis.jl, please make sure you are able to check off each item on this list:

• Did I update CHANGELOG.md with whatever changes/features I added with this PR?
• Did I make sure to only change the part of the file where I introduced a new change/feature?
• Did I cover all corner cases to be close to 100% test coverage (if applicable)?
• Did I properly add Javis dependencies to the Project.toml + set an upper bound of the dependency (if applicable)?
• Did I properly add test dependencies to the test directory (if applicable)?
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• Did I clearly articulate why this PR was made the way it was and how it was made?

How did you address these issues with this PR? What methods did you use?
This PR introduces some manim like modes for morphing
https://azarzadavila-manim.readthedocs.io/en/latest/animation.html#transform

TEST SCRIPT

[codecov]

Codecov Report

Merging #374 (b79ff00) into master (d42cbf4) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #374   +/-   ##
=======================================
  Coverage   96.25%   96.25%           
=======================================
  Files          35       35           
  Lines        1521     1523    +2     
=======================================
+ Hits         1464     1466    +2     
  Misses         57       57           

Impacted Files	Coverage Δ
src/Shape.jl	97.05% <100.00%> (+0.03%)	⬆️
src/morphs.jl	96.46% <100.00%> (ø)

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[Wikunia]

Just a minor comment here. Let me know when I should do a proper full review

[Sov-trotter]

@Wikunia since the goal here is more visual appeal, should we provide some default easing function(apart from linear()) in this PR??

[Wikunia]

I think it makes sense to have the easing separated from the function to have it more composable. The default for all actions should be linear() I think. We might want to create predefined actions similar to predefined objects in the future where we can tackle this. What do you think?

[Sov-trotter]

I think it makes sense to have the easing separated from the function to have it more composable.

Understood. I was just of the opinion, that in longer running videos it would rather be easy for the user if the small morphs had atleast some visual appeal by default.

We might want to create predefined actions similar to predefined objects in the future where we can tackle this.

Sure yeah. I had thought of that while tackling predefined objects. There are a few things to look into before that.
First is making the Javis Recipes(which are obviously actions) more "available". I mean to say that the users don't have to create overloads like:
(video, object, action, rel_frame) -> _translate(video, object, action, rel_frame)
and then go on to define their custom actions in _foo function.

Maybe a macro is handy here.
So this itself accounts for predefined actions(for recipes/internally)

Secondly we can have some predefined actions but at present I still don't know we to wrap around? Would like to hear what ideas you have.

[Wikunia]

Let's discuss that tmr in our meeting 😉

[Sov-trotter]

Self TODO : Check if morphing modes work with #373

[Wikunia]

One minor thing

[Wikunia]

Still not a fan of :long how about :shortest_dist and :visually_appealing ?
Maybe also add how it works in the docstring of morph_to.

[Wikunia]

We've decided to call those modes mode1, mode2, ... and have animations in the docs for the different morphing modes.
Additionally it would be good to have arguments to parameterize some of the modes like the one implemented in this PR

[Wikunia]

Should be updated here as well