pygame 弹力球及其变速的实现

 1 import pygame
 2 from pygame.locals import *
 3 import sys, random
 4 
 5 
 6 class Circle(object):
 7     #   设置Circle类属性
 8     def __init__(self):
 9         self.vel_x = 1
10         self.vel_y = 1
11         self.radius = 20
12         self.pos_x, self.pos_y = random.randint(0, 255), random.randint(0, 255)
13         self.width = 0
14         self.color = 0, 0, 0
15 
16     #   球体颜色速度改变方法
17     def change_circle(self, number):
18         self.color = random.randint(0, 255), random.randint(0, 255), random.randint(0, 255)
19         #   防止球体速度方向发生改变
20         if self.vel_x < 0:
21             self.vel_x = -number
22         else:
23             self.vel_x = number
24         if self.vel_y < 0:
25             self.vel_y = -number
26         else:
27             self.vel_y = number
28         #   self.vel_x, self.vel_y = number, number  如果仅此句，速度方向会发生改变
29 
30     def circle_run(self):
31         #   防止球体超出游戏界面框体
32         if self.pos_x > 580 or self.pos_x < 20:
33             self.vel_x = -self.vel_x
34 
35         if self.pos_y > 480 or self.pos_y < 20:
36             self.vel_y = -self.vel_y
37         self.pos_x += self.vel_x
38         self.pos_y += self.vel_y
39         pos = self.pos_x, self.pos_y
40         pygame.draw.circle(screen, self.color, pos, self.radius, self.width)
41 
42 pygame.init()
43 screen = pygame.display.set_mode((600, 500))
44 #   Circle实例
45 circle1 = Circle()
46 
47 while True:
48     for event in pygame.event.get():
49         if event.type == QUIT:
50             sys.exit()
51         elif event.type == KEYUP:
52             if event.key == pygame.K_1:
53                 circle1.change_circle(1)
54             elif event.key == pygame.K_2:
55                 circle1.change_circle(2)
56             elif event.key == pygame.K_3:
57                 circle1.change_circle(3)
58             elif event.key == pygame.K_4:
59                 circle1.change_circle(4)
60 
61     screen.fill((0, 0, 100))
62 
63     circle1.circle_run()
64 
65     pygame.display.update()