def construct(self):
# Set objets
theta = ValueTracker(self.theta)
line_1 = Line(ORIGIN, RIGHT * self.lines_size, color=self.line_1_color)
line_2 = Line(ORIGIN, RIGHT * self.lines_size, color=self.line_2_color)
line_2.rotate(theta.get_value(), about_point=ORIGIN)
line_2.add_updater(lambda m: m.set_angle(theta.get_value()))
angle = Arc(radius=self.radius,
start_angle=line_1.get_angle(),
angle=line_2.get_angle(),
color=self.radius_color)
# Show the objects
self.play(*[ShowCreation(obj) for obj in [line_1, line_2, angle]])
# Set update function to angle
angle.add_updater(lambda m: m.become(
Arc(radius=self.radius,
start_angle=line_1.get_angle(),
angle=line_2.get_angle(),
color=self.radius_color)))
# Remember to add the objects again to the screen
# when you add the add_updater method.
self.add(angle)
self.play(theta.increment_value, self.increment_theta)
# self.play(theta.set_value,self.final_theta)
self.wait()
def construct(self):
theta = ValueTracker(PI / 2)
line_1 = Line(ORIGIN, RIGHT * 3, color=RED)
line_2 = Line(ORIGIN, RIGHT * 3, color=GREEN)
line_2.rotate(theta.get_value(), about_point=ORIGIN)
line_2.add_updater(lambda m: m.set_angle(theta.get_value()))
self.add(line_1, line_2)
self.play(theta.increment_value, PI / 2)
self.wait()
