Source code for manim.animation.updaters.update

"""Animations that update mobjects."""

from __future__ import annotations

__all__ = ["UpdateFromFunc", "UpdateFromAlphaFunc", "MaintainPositionRelativeTo"]

import operator as op
import typing

from manim.animation.animation import Animation

if typing.TYPE_CHECKING:
    from manim.mobject.mobject import Mobject

[docs] class UpdateFromFunc(Animation): """ update_function of the form func(mobject), presumably to be used when the state of one mobject is dependent on another simultaneously animated mobject """ def __init__( self, mobject: Mobject, update_function: typing.Callable[[Mobject], typing.Any], suspend_mobject_updating: bool = False, **kwargs, ) -> None: self.update_function = update_function super().__init__( mobject, suspend_mobject_updating=suspend_mobject_updating, **kwargs )
[docs] def interpolate_mobject(self, alpha: float) -> None: self.update_function(self.mobject)
[docs] class UpdateFromAlphaFunc(UpdateFromFunc):
[docs] def interpolate_mobject(self, alpha: float) -> None: self.update_function(self.mobject, self.rate_func(alpha))
[docs] class MaintainPositionRelativeTo(Animation): def __init__(self, mobject: Mobject, tracked_mobject: Mobject, **kwargs) -> None: self.tracked_mobject = tracked_mobject self.diff = op.sub( mobject.get_center(), tracked_mobject.get_center(), ) super().__init__(mobject, **kwargs)
[docs] def interpolate_mobject(self, alpha: float) -> None: target = self.tracked_mobject.get_center() location = self.mobject.get_center() self.mobject.shift(target - location + self.diff)