Source code for manim.animation.update

"""Animations that update mobjects."""

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

import operator as op
import typing

from ..animation.animation import Animation

if typing.TYPE_CHECKING:
    from ..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)