在python海龟中定义一个区域

Question

所以我的目标是当我在 turtle 屏幕上的特定区域内单击时发生一个函数。因此，当我的乌龟绘制一个正方形并且我在正方形内单击时，我需要发生一些事情。

示例：

turtle.onscreenclick(turtle.goto)

for i in range(4):
      turtle.forward(30)
      turtle.left(90)

if turtle.position() == (within square region):
      Activate function()

Answer 1

如果您的意思是仅允许 goto 进入正方形：

import turtle

def goto_inside(x, y):
    if 0 <= x <= 30 and 0 <= y <= 30:
        turtle.goto(x, y)

turtle.onscreenclick(goto_inside)

# draw a square 30x30
for i in range(4):
    turtle.forward(30)
    turtle.left(90)

# turtle.mainloop()

Answer 2

您需要计算出正方形所定义区域的范围，以便稍后将鼠标单击位置与其进行比较，看看它们是否在正方形内。下面是一个完整的程序，首先让鼠标点击定义一个正方形的左下角，绘制它，然后每次鼠标在矩形区域内点击时调用指定的函数。

import turtle

def draw_square(x, y):
    global target_region

    turtle.penup()
    turtle.goto(x, y)
    turtle.setheading(0)
    turtle.pendown()
    square = []
    for i in range(4):
        square.append(turtle.pos())  # Save turtle coords
        turtle.forward(30)
        turtle.left(90)

    # Find min and max coordinates of region
    min_x = min(square, key=lambda p: p[0])[0]
    min_y = min(square, key=lambda p: p[1])[1]
    max_x = max(square, key=lambda p: p[0])[0]
    max_y = max(square, key=lambda p: p[1])[1]
    target_region = [min_x, min_y, max_x, max_y]

    turtle.hideturtle()
    turtle.onscreenclick(check_click)  # Switch to next event handler

def check_click(x, y):
    if (target_region[0] <= x <= target_region[2] and
        target_region[1] <= y <= target_region[3]):  # Within square region?
        within_square_region_function()  # Call activate function

def within_square_region_function():
    print('clicked in square')

turtle.onscreenclick(draw_square)  # Set initial event handler
turtle.mainloop()

在python海龟中定义一个区域

Define a region in python turtle

python

turtle-graphics