围绕椭圆移动圆圈

Question

我不明白，如何在椭圆周围移动圆圈？椭圆坐标必须由用户输入，并且每次都会改变，我怎么办那个圆圈总是围绕椭圆？我知道我的代码是错误的，它只能绕圆移动，但我需要椭圆，这只是原型。

import tkinter as tk
from math import cos, sin, radians

root = tk.Tk()
root.geometry("1000x1000")

canvas = tk.Canvas(root, background="black")
canvas.pack(fill="both",expand=True)

image = tk.PhotoImage(file="unnamed.png").subsample(7,7)

x2= int(input('enter radius x :'))
y2= int(input('enter radius y:'))
def create_circle(x, y, r, canvasName):
    x0 = x - r
    y0 = y - r
    x1 = x + r
    y1 = y + r

    return canvas.create_oval(x0,y0,x1,y1, outline = 'red')

def move(angle):
    if angle >=360:
        angle = 0
    x = 200 * cos(radians(angle))
    y = 200 * sin(radians(angle))
    angle+=1
    canvas.coords(circle, x2+x, y2+y)
    root.after(10, move, angle)
    
create_circle (x2,y2,200,canvas)
circle = canvas.create_image(200,100,image=image)

root.after(10, move, 0)

root.mainloop()

Answer 1

没有内置的方法来实现这一点。所以，你必须自己计算。

tkinter 中的圆由 (x1, y1, x2, y2) 定义，即矩形（或正方形）。

这是一张图片，解释了如何在 tkinter 中绘制圆以及如何找到 (x, y)

上图中的θ是角度

这里的 (s, t) 分别由方程 (x2-x1)/2 和 (y2-y1)/2 定义

这是您之前代码的演示（在您编辑代码之前）。：

from tkinter import *
import math

x = 10
y = 10
a = 50
b = 50
t = 0

radius = 50 #radius around the circle

x_vel = 5
y_vel = 5

def move():

    global x, y, x_vel, y_vel, t, radius

    if x < 0:
        x_vel = 5
    if x > 700:
        x_vel = -5
    if y < 0:
        y_vel = 5
    if y > 700:
        y_vel = -5

    
    canvas1.move(circle, x_vel, y_vel)

    rx, ry, rw, rh = canvas1.coords(circle)
    
    rx1 = ((rw-rx)/2) +radius   # gets the s of the main circle
    ry1 = ((rh-ry)/2) +radius   # gets the t of the main circle


    cx = rx1*math.cos(t) + ry1*math.sin(t)
    cy = -rx1*math.sin(t) + ry1*math.cos(t)

    t += 1 # jump by how many degree
    

    if t > 360:
        t=0

    canvas1.moveto(rect2, cx+x, cy+y)

    x = rx
    y = ry
    
    window.after(33, move)
 
window   = Tk()
window.geometry("1000x1000")

canvas1=Canvas(window, height = 1000, width= 1000)
canvas1.grid (row=0, column=0, sticky=W)
coord = [x, y, a, b ]
circle = canvas1.create_oval(coord, outline="red", fill="red")
 
x0=  int(input("enter x center coord"))
y0= int(input("enter y center coord"))
coord = [x0, y0, y0, x0]
rect2 = canvas1.create_oval(coord, outline="Red", fill="")

move()
window.mainloop ()