def update(self, dt):
# Not actual time, but something which passes at
# an altered rate to make the implementation below
# cleaner
time = self.total_time * self.cycle_rate
growing, fading = self.boundary_copies
colors = self.colors
msw = self.max_stroke_width
vmobject = self.vmobject
index = int(time % len(colors))
alpha = smooth(time % 1)
if int(time) % 2 == 0:
bounds = (0, alpha)
else:
bounds = (1 - alpha, 1)
self.full_family_become_partial(growing, vmobject, *bounds)
growing.set_stroke(colors[index], width=msw)
if time >= 1:
self.full_family_become_partial(fading, vmobject, 0, 1)
fading.set_stroke(color=colors[index - 1], width=(1 - alpha) * msw)
self.total_time += dt
class UnGrowFromRandom(GrowFromRandom):
CONFIG = {
"anim_kwargs": {
"rate_func": lambda t: smooth(1 - t)
},
"remover": True
}
class UnWriteRandom(WriteRandom):
CONFIG = {
"anim_kwargs": {
"rate_func": lambda t: smooth(1 - t)
},
"remover": True,
}
def do_vectors_only_period_hide(self, _, alpha):
fade_ratio = 3
if alpha >= (fade_ratio - 1) / fade_ratio:
opacity = 1 - smooth(fade_ratio * alpha - (fade_ratio - 1))
self.x_vector.set_opacity(opacity)
self.y_vector.set_opacity(opacity)
self.xy_vector.set_opacity(opacity)
self.ellipse.set_stroke(opacity=opacity)
self.do_vectors_only_period(_, alpha)
def get_sub_alpha(self, alpha, index, num_submobjects):
if self.submobject_mode in ["lagged_start", "smoothed_lagged_start"]:
prop = float(index) / num_submobjects
if self.submobject_mode is "smoothed_lagged_start":
prop = smooth(prop)
lf = self.lag_factor
return np.clip(lf * alpha - (lf - 1) * prop, 0, 1)
elif self.submobject_mode == "one_at_a_time":
lower = float(index) / num_submobjects
upper = float(index + 1) / num_submobjects
return np.clip((alpha - lower) / (upper - lower), 0, 1)
elif self.submobject_mode == "all_at_once":
return alpha
raise Exception("Invalid submobject mode")
class Uncreate(ShowCreation):
"""
Type: ``ShowCreation``
``CONFIG`` parameters
::
"rate_func": lambda t: smooth(1 - t),
"remover": True
"""
CONFIG = {
"rate_func": lambda t: smooth(1 - t),
"remover": True
}
def get_sub_alpha(self, alpha, index, num_submobjects):
# TODO, make this more understanable, and/or combine
# its functionality with AnimationGroup's method
# build_animations_with_timings
lag_ratio = self.lag_ratio
full_length = (num_submobjects - 1) * lag_ratio + 1
value = alpha * full_length
lower = index * lag_ratio
if self.submobject_mode in ["lagged_start", "smoothed_lagged_start"]:
prop = float(index) / num_submobjects
if self.submobject_mode is "smoothed_lagged_start":
prop = smooth(prop)
lf = self.lag_factor
return np.clip(lf * alpha - (lf - 1) * prop, 0, 1)
elif self.submobject_mode == "one_at_a_time":
lower = float(index) / num_submobjects
upper = float(index + 1) / num_submobjects
return np.clip((alpha - lower) / (upper - lower), 0, 1)
elif self.submobject_mode == "all_at_once":
return alpha
return np.clip((value - lower), 0, 1)
class Uncreate(ShowCreation):
CONFIG = {
"rate_func": lambda t: smooth(1 - t),
"remover": True,
"should_match_start": True,
}
class Uncreate(ShowCreation):
CONFIG = {
"rate_func": lambda t: smooth(1 - t),
"remover": True
}
def construct(self):
text = TextMobject("Hello")
# Just run rate_func backward
self.play(Write(text, rate_func=lambda t: smooth(1 - t)))
self.wait()
