Files
manim/manimlib/continual_animation/continual_animation.py

104 lines
2.9 KiB
Python

import copy
from manimlib.constants import *
from manimlib.mobject.mobject import Group
from manimlib.mobject.mobject import Mobject
from manimlib.utils.config_ops import digest_config
from manimlib.utils.config_ops import instantiate
class ContinualAnimation(object):
CONFIG = {
"start_up_time": 1,
"wind_down_time": 1,
"end_time": np.inf,
}
def __init__(self, mobject, **kwargs):
mobject = instantiate(mobject)
assert(isinstance(mobject, Mobject))
digest_config(self, kwargs, locals())
self.internal_time = 0
self.external_time = 0
self.setup()
self.update(0)
def setup(self):
# To implement in subclass
pass
def begin_wind_down(self, wind_down_time=None):
if wind_down_time is not None:
self.wind_down_time = wind_down_time
self.end_time = self.external_time + self.wind_down_time
def update(self, dt):
# TODO, currenty time moves slower for a
# continual animation during its start up
# to help smooth things out. Does this have
# unwanted consequences?
self.external_time += dt
if self.external_time < self.start_up_time:
dt *= float(self.external_time) / self.start_up_time
elif self.external_time > self.end_time - self.wind_down_time:
dt *= np.clip(
float(self.end_time - self.external_time) / self.wind_down_time,
0, 1
)
self.internal_time += dt
self.update_mobject(dt)
def update_mobject(self, dt):
# To implement in subclass
pass
def copy(self):
return copy.deepcopy(self)
class ContinualAnimationGroup(ContinualAnimation):
CONFIG = {
"start_up_time": 0,
"wind_down_time": 0,
}
def __init__(self, *continual_animations, **kwargs):
digest_config(self, kwargs, locals())
self.group = Group(*[ca.mobject for ca in continual_animations])
ContinualAnimation.__init__(self, self.group, **kwargs)
def update_mobject(self, dt):
for continual_animation in self.continual_animations:
continual_animation.update(dt)
class ContinualRotation(ContinualAnimation):
CONFIG = {
"axis": OUT,
"rate": np.pi / 12, # Radians per second
"in_place": True,
"about_point": None,
}
def update_mobject(self, dt):
if self.about_point:
about_point = self.about_point
elif self.in_place:
about_point = self.mobject.get_center()
else:
about_point = ORIGIN
self.mobject.rotate(
dt * self.rate, axis=self.axis,
about_point=about_point
)
class ContinualMovement(ContinualAnimation):
CONFIG = {
"direction": RIGHT,
"rate": 0.05, # Units per second
}
def update_mobject(self, dt):
self.mobject.shift(dt * self.rate * self.direction)