manim 2d demo.py

from manimlib.imports import *


class Main(Scene):
    def construct(self):
        dot = Dot()
        line = Line()
        arrow = Arrow()
        circle = Circle()
        annulus = Annulus()
        triangle = Triangle()
        rectangle = Rectangle()

        self.play(Transform(dot, line))
        self.play(Transform(dot, arrow))
        self.play(Transform(dot, circle))
        self.play(Transform(dot, annulus))
        self.play(Transform(dot, triangle))
        self.play(Transform(dot, rectangle))
        self.play(FadeOut(dot))
        self.clear()

        rectangle = Rectangle(color=RED, width=1, height=1).set_fill(color=RED, opacity=0.5).move_to(LEFT_SIDE)
        flag = ImageMobject('media/china.jpeg', height=1).next_to(rectangle)
        counter = Integer(1101).next_to(flag)
        self.play(FadeIn(rectangle), FadeIn(flag), FadeIn(counter))

        # 矩形更新
        def update_width(ob):
            print(f'current {ob.width}')
            ob.width += 1
            ob.shift(UP*0.1)
            ob.set_width(ob.width, stretch=True)

        rectangle.add_updater(update_width)
        # 数字更新
        counter.add_updater(lambda ob: ob.set_value(rectangle.get_width()))

        # 位置更新
        flag.add_updater(lambda  ob: ob.next_to(rectangle))
        counter.add_updater(lambda  ob: ob.next_to(flag))

        self.play(Write(Line(start=LEFT_SIDE, end=RIGHT_SIDE).move_to(BOTTOM)))
        self.wait()