### 伪3D拦彩球小游戏主程序

```"""
伪3D拦彩球小游戏.py
本程序新建Ball类,球实例化后会在定时器的作用下不断地自我移动与进行碰撞检测。
"""
from glob import glob
from board import Board
from time import sleep
from turtle import Screen,Turtle
from random import randint,choice

class Ball(Turtle):
def __init__(self,image,board ):
"""image:已注册的gif图，board：拦板对象"""
Turtle.__init__(self,shape=image,visible=False)
self.penup()
self.board = board
self.xspeed = choice(speeds)
self.yspeed = choice(speeds)
self.sw = self.screen.window_width()   # 屏幕宽度属性
self.sh = self.screen.window_height()  # 屏幕高度属性
self.goto(self.sw//2,self.sh//2)
self.showturtle()
self.move()

def move(self):
"""移动小球方法"""
x = self.xcor() + self.xspeed        # 新的x坐标是原坐标加xspeed
y = self.ycor() + self.yspeed        # 新的y坐标是原坐标加yspeed
self.goto(x,y)
left = x - 13                        # 小球最左边的x坐标
right = x + 13                       # 小球最右边的x坐标
top = y-13                           # 小球最上边的y坐标
bottom = y + 13                      # 小球最下边的y坐标
c1 = left <= 0
c2 = right >= self.sw
if c1 or c2 :                        # 左或右超过边缘
self.xspeed = -self.xspeed       # x速度取反

c3 = top <= 0
c4 = top >= self.sh
if c3 :                              # 超过上边缘
self.yspeed = -self.yspeed       # y速度取反
if c4 :                              # 超过下边缘