Improve Updater signature checks for substantial speedups, add UpdaterWrappers and more Updater aliases

[chopan050]

Closes #321

General description

In the issue described, Leo mentions that calling inspect.signature() every time we need to compute whether an Updater is time-based or not, takes a considerable amount of time when there are a lot of updaters in a Scene.

Leo proposed that every updater must always have two parameters and made a PR about it, but it was rejected.

Given an updater func, my first attempt was accessing func.__code__.co_varnames (local variable names in the function code) and slice it from 0 to func.__code__.co_argcount (number of positional parameters) to get the names of positional parameters.

However, as JasonGrace commented his concerns about more advanced use cases, I needed something more.

Therefore, in this PR I introduce a MobjectUpdaterWrapper, which takes an updater function, saves it in its .updater attribute, and uses inspect.signature() on it to calculate whether it's time-based or not. It stores the result in its .is_time_based, and this computation only happens once (when instantiating MobjectUpdaterWrapper), rather than every time the updater is called, leading to a substantial speedup when updating Mobjects.

In MobjectUpdaterWrapper I also address the concerns raised by JasonGrace, Leo and myself:

• What if the updater function has parameters with default values?
• What if there's no parameter named dt in the signature?
• What if the function only has two parameters, but the 2nd one has a default value and is not intended to receive a dt value?
• What if the function is a method and its 1st parameter is self?
• What if the function isn't a method, but the 1st parameter is self anyways?
• etc.

which is why I decided to make a separate class in the first place: the logic which attempts to address all these concerns is very long and shouldn't bloat the Mobject.add_updater() code. Plus, I wanted to replicate the same for OpenGLMobject as well.

Because I wanted to make the same changes in OpenGLMobject, the best course of action was taking all this code into a different module, specifically manim.utils.updaters.

I also noticed that the relatively obscure classes Object3D and its subclass Mesh also have updaters which work in a very similar fashion, so I added the MeshUpdater type alias and the MeshUpdaterWrapper class as well.

Finally, Scene also has updaters, but very different ones (they always accept a dt: float and return None), so I also added a SceneUpdater type alias.

Profiling

An example scene with many updaters:

class MovingSquares(Scene):
    def construct(self):
        t = ValueTracker()
        for y in range(4, -5, -2):
            for x in range(-8, 9, 2):
                updater = (lambda x, y: (
                    lambda square, dt: square.move_to([
                        x + np.cos(t.get_value()),
                        y + (1 if x % 4 == 0 else -1) * np.sin(t.get_value()),
                        0,
                    ])
                ))(x, y)
                self.add(Square(1).add_updater(updater))

        self.play(t.animate.set_value(2*TAU), run_time=10, rate_func=linear)

Notice how the inspect.signature() block completely disappears from the Mobject.update() time:

Before	After

Links to added or changed documentation pages

https://manimce--3807.org.readthedocs.build/en/3807/reference/manim.utils.updaters.html

Further Information and Comments

Reviewer Checklist

• The PR title is descriptive enough for the changelog, and the PR is labeled correctly
• If applicable: newly added non-private functions and classes have a docstring including a short summary and a PARAMETERS section
• If applicable: newly added functions and classes are tested

[JasonGrace2282]

Haven't looked through the whole thing, but just off a glance through, I left some comments

Hopefully, this makes the updater situation better in future versions of manim :)

[github-advanced-security]

CodeQL found more than 20 potential problems in the proposed changes. Check the Files changed tab for more details.