from manim import *

class CapacitorChargingDischarging(Scene):
    def construct(self):
        # 创建电容和电阻
        capacitor = Rectangle(width=2, height=1.5, fill_color=BLUE, fill_opacity=0.5)
        resistor = Rectangle(width=1, height=0.2, fill_color=GRAY, fill_opacity=0.5)

        # 将电容和电阻放置在场景中
        capacitor.move_to(LEFT * 2)
        resistor.move_to(RIGHT * 2)
        self.add(capacitor, resistor)

        # 创建电源和电压标签
        power_source = Arrow(start=LEFT * 1.5, end=RIGHT * 1.5, color=YELLOW)
        voltage_label = Tex("V").next_to(power_source, UP)
        self.add(power_source, voltage_label)

        # 创建电容电压标签
        capacitor_voltage_label = Tex("V_c").next_to(capacitor, UP)
        self.add(capacitor_voltage_label)

        # 定义动画函数
        def charging_animation(t):
            voltage = 10 * (1 - np.exp(-t))
            capacitor_voltage_label.set_value(voltage)
            return capacitor_voltage_label

        def discharging_animation(t):
            if t < 5:
                return capacitor_voltage_label
            else:
                voltage = 10 * np.exp(-(t - 5))
                capacitor_voltage_label.set_value(voltage)
                return capacitor_voltage_label

        # 运行充电动画
        self.play(UpdateFromFunc(capacitor_voltage_label, charging_animation, run_time=10))

        # 暂停一段时间
        self.wait(2)

        # 运行放电动画
        self.play(UpdateFromFunc(capacitor_voltage_label, discharging_animation, run_time=10))