3b1b-manim/manimlib/mobject/functions.py
2021-02-06 11:39:19 -08:00

70 lines
2.2 KiB
Python

from manimlib.constants import *
from manimlib.mobject.types.vectorized_mobject import VMobject
from manimlib.utils.config_ops import digest_config
class ParametricCurve(VMobject):
CONFIG = {
"t_range": [0, 1, 0.1],
"epsilon": 1e-8,
# TODO, automatically figure out discontinuities
"discontinuities": [],
"use_smoothing": True,
}
def __init__(self, t_func, t_range=None, **kwargs):
digest_config(self, kwargs)
if t_range is not None:
self.t_range[:len(t_range)] = t_range
# To be backward compatible with all the scenes specifying t_min, t_max, step_size
self.t_range = [
kwargs.get("t_min", self.t_range[0]),
kwargs.get("t_max", self.t_range[1]),
kwargs.get("step_size", self.t_range[2]),
]
self.t_func = t_func
VMobject.__init__(self, **kwargs)
def get_point_from_function(self, t):
return self.t_func(t)
def init_points(self):
t_min, t_max, step = self.t_range
jumps = np.array(self.discontinuities)
jumps = jumps[(jumps > t_min) & (jumps < t_max)]
boundary_times = [t_min, t_max, *(jumps - self.epsilon), *(jumps + self.epsilon)]
boundary_times.sort()
for t1, t2 in zip(boundary_times[0::2], boundary_times[1::2]):
t_range = [*np.arange(t1, t2, step), t2]
points = np.array([self.t_func(t) for t in t_range])
self.start_new_path(points[0])
self.add_points_as_corners(points[1:])
if self.use_smoothing:
self.make_approximately_smooth()
return self
class FunctionGraph(ParametricCurve):
CONFIG = {
"color": YELLOW,
"x_range": [-8, 8, 0.25],
}
def __init__(self, function, x_range=None, **kwargs):
digest_config(self, kwargs)
self.function = function
if x_range is not None:
self.x_range[:len(x_range)] = x_range
def parametric_function(t):
return [t, function(t), 0]
super().__init__(parametric_function, self.x_range, **kwargs)
def get_function(self):
return self.function
def get_point_from_function(self, x):
return self.t_func(x)