3b1b-manim/manimlib/animation/movement.py

73 lines
2.2 KiB
Python

from manimlib.animation.animation import Animation
from manimlib.constants import *
from manimlib.utils.config_ops import digest_config
class Homotopy(Animation):
CONFIG = {
"run_time": 3,
"apply_function_kwargs": {},
}
def __init__(self, homotopy, mobject, **kwargs):
"""
Homotopy a function from (x, y, z, t) to (x', y', z')
"""
def function_at_time_t(t):
return lambda p: homotopy(p[0], p[1], p[2], t)
self.function_at_time_t = function_at_time_t
digest_config(self, kwargs)
Animation.__init__(self, mobject, **kwargs)
def update_submobject(self, submob, start, alpha):
submob.points = start.points
submob.apply_function(
self.function_at_time_t(alpha),
**self.apply_function_kwargs
)
class SmoothedVectorizedHomotopy(Homotopy):
def update_submobject(self, submob, start, alpha):
Homotopy.update_submobject(self, submob, start, alpha)
submob.make_smooth()
class ComplexHomotopy(Homotopy):
def __init__(self, complex_homotopy, mobject, **kwargs):
"""
Complex Hootopy a function Cx[0, 1] to C
"""
def homotopy(x, y, z, t):
c = complex_homotopy(complex(x, y), t)
return (c.real, c.imag, z)
Homotopy.__init__(self, homotopy, mobject, **kwargs)
class PhaseFlow(Animation):
CONFIG = {
"virtual_time": 1,
"rate_func": None,
}
def __init__(self, function, mobject, **kwargs):
digest_config(self, kwargs, locals())
Animation.__init__(self, mobject, **kwargs)
def update_mobject(self, alpha):
if hasattr(self, "last_alpha"):
dt = self.virtual_time * (alpha - self.last_alpha)
self.mobject.apply_function(
lambda p: p + dt * self.function(p)
)
self.last_alpha = alpha
class MoveAlongPath(Animation):
def __init__(self, mobject, path, **kwargs):
digest_config(self, kwargs, locals())
Animation.__init__(self, mobject, **kwargs)
def update_mobject(self, alpha):
point = self.path.point_from_proportion(alpha)
self.mobject.move_to(point)