Tkinter perspective experiment

script.py

import tkinter
import time

master = tkinter.Tk()

canvas = tkinter.Canvas(master, width=1000, height=1000)
canvas.pack()

def animation():
    def draw_point(x, y, c='black'):
        canvas.create_rectangle(x, y, x + 1, y + 1, fill=c)

    r = 200
    bottom_x, bottom_y = 500, 900
    tick = 0
    point_x, point_y = 500, 20
    point_speed_x = 10
    min_x, max_x = 20, 1000 - 20
    point_r = 5
    while True:

        prev_h = 0
        canvas.create_rectangle(0, 0, 1000, 1000, fill='white')
        for i in range(1, 2 * r + 1):
            curr_h = (r**2 - (r - i) ** 2) ** 0.5
            canvas.create_line(bottom_x + prev_h, bottom_y - i + 1,
                               bottom_x + curr_h, bottom_y - i)
            canvas.create_line(bottom_x - prev_h, bottom_y - i + 1,
                               bottom_x - curr_h, bottom_y - i)
            prev_h = curr_h

        canvas.create_oval(point_x - point_r, point_y - point_r,
                           point_x + point_r, point_y + point_r,
                           fill='red')

        canvas.create_line(bottom_x - r, bottom_y,
                           bottom_x + r, bottom_y)
        canvas.create_line(bottom_x - r, bottom_y - 2 * r,
                           bottom_x + r, bottom_y - 2 * r)
        canvas.create_line(bottom_x - r, bottom_y,
                           bottom_x - r, bottom_y - 2 * r)
        canvas.create_line(bottom_x + r, bottom_y,
                           bottom_x + r, bottom_y - 2 * r)

        def transform(x, y):
            scale = (bottom_y - y) / float(bottom_y - point_y)
            middle_x = bottom_x + (point_x - bottom_x) * scale
            return middle_x + (x - bottom_x) * (1 - scale), y

        canvas.create_line(*transform(bottom_x - r, bottom_y), point_x, point_y)
        canvas.create_line(*transform(bottom_x + r, bottom_y), point_x, point_y)

        canvas.create_line(*transform(bottom_x - r, bottom_y),
                           *transform(bottom_x + r, bottom_y))
        canvas.create_line(*transform(bottom_x - r, bottom_y - 2 * r),
                           *transform(bottom_x + r, bottom_y - 2 * r))
        canvas.create_line(*transform(bottom_x - r, bottom_y),
                           *transform(bottom_x - r, bottom_y - 2 * r))
        canvas.create_line(*transform(bottom_x + r, bottom_y),
                           *transform(bottom_x + r, bottom_y - 2 * r))

        prev_h = 0
        for i in range(1, 2 * r + 1):
            curr_h = (r**2 - (r - i) ** 2) ** 0.5
            canvas.create_line(*transform(bottom_x + prev_h, bottom_y - i + 1),
                               *transform(bottom_x + curr_h, bottom_y - i),
                               fill='red', width=2)
            canvas.create_line(*transform(bottom_x - prev_h, bottom_y - i + 1),
                               *transform(bottom_x - curr_h, bottom_y - i),
                               fill='red', width=2)
            prev_h = curr_h

        tick += 1
        point_x += point_speed_x
        if point_x >= max_x or point_x <= min_x:
            point_speed_x *= -1
        canvas.update()
        time.sleep(0.025)

master.after(0, animation)
tkinter.mainloop()