def turn_animation_into_updater(animation: Animation,
cycle: bool = False,
**kwargs) -> Mobject:
"""
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 uplon completion
"""
mobject = animation.mobject
animation.update_config(**kwargs)
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 = 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
def begin(self) -> None:
self.ending_mobject = self.mobject.copy()
Animation.begin(self)
# Both 'start' and 'end' consists of the source and target mobjects.
# At the start, the traget should be faded replacing the source,
# and at the end it should be the other way around.
start, end = self.starting_mobject, self.ending_mobject
for m0, m1 in ((start[1], start[0]), (end[0], end[1])):
self.ghost_to(m0, m1)
