Source code for manim.animation.updaters.mobject_update_utils

"""Utility functions for continuous animation of mobjects."""

from __future__ import annotations

__all__ = [

import inspect

import numpy as np

from manim.constants import DEGREES, RIGHT
from manim.mobject.mobject import Mobject
from manim.opengl import OpenGLMobject

[docs]def assert_is_mobject_method(method): assert inspect.ismethod(method) mobject = method.__self__ assert isinstance(mobject, (Mobject, OpenGLMobject))
[docs]def always(method, *args, **kwargs): assert_is_mobject_method(method) mobject = method.__self__ func = method.__func__ mobject.add_updater(lambda m: func(m, *args, **kwargs)) return mobject
[docs]def f_always(method, *arg_generators, **kwargs): """ More functional version of always, where instead of taking in args, it takes in functions which output the relevant arguments. """ assert_is_mobject_method(method) mobject = method.__self__ func = method.__func__ def updater(mob): args = [arg_generator() for arg_generator in arg_generators] func(mob, *args, **kwargs) mobject.add_updater(updater) return mobject
[docs]def always_redraw(func): mob = func() mob.add_updater(lambda m: mob.become(func())) return mob
[docs]def always_shift(mobject, direction=RIGHT, rate=0.1): def normalize(v): norm = np.linalg.norm(v) if norm == 0: return v return v / norm mobject.add_updater(lambda m, dt: m.shift(dt * rate * normalize(direction))) return mobject
[docs]def always_rotate(mobject, rate=20 * DEGREES, **kwargs): mobject.add_updater(lambda m, dt: m.rotate(dt * rate, **kwargs)) return mobject
[docs]def turn_animation_into_updater(animation, cycle=False, **kwargs): """ Add an updater to the animation's mobject which applies the interpolation and update functions of the animation If cycle is True, this repeats over and over. Otherwise, the updater will be popped upon completion """ mobject = animation.mobject animation.suspend_mobject_updating = False animation.begin() animation.total_time = 0 def update(m, dt): run_time = animation.get_run_time() time_ratio = animation.total_time / run_time if cycle: alpha = time_ratio % 1 else: alpha = np.clip(time_ratio, 0, 1) if alpha >= 1: animation.finish() m.remove_updater(update) return animation.interpolate(alpha) animation.update_mobjects(dt) animation.total_time += dt mobject.add_updater(update) return mobject
[docs]def cycle_animation(animation, **kwargs): return turn_animation_into_updater(animation, cycle=True, **kwargs)