pygame 弹力球及其变速的实现

期望：

1.球体接触到框体后反弹

2.设置速度按键，按下后改变球体速度、颜色状态

具体实现：

import pygame
from pygame.locals import *
import sys, random

class Circle(object):
    #   设置Circle类属性
    def __init__(self):
        self.vel_x = 1
        self.vel_y = 1
        self.radius = 20
        self.pos_x, self.pos_y = random.randint(0, 255), random.randint(0, 255)
        self.width = 0
        self.color = 0, 0, 0

    #   球体颜色速度改变方法
    def change_circle(self, number):
        self.color = random.randint(0, 255), random.randint(0, 255), random.randint(0, 255)
        #   防止球体速度方向发生改变
        if self.vel_x < 0:
            self.vel_x = -number
        else:
            self.vel_x = number
        if self.vel_y < 0:
            self.vel_y = -number
        else:
            self.vel_y = number
        #   self.vel_x, self.vel_y = number, number  如果仅此句，速度方向会发生改变

    def circle_run(self):
        #   防止球体超出游戏界面框体
        if self.pos_x > 580 or self.pos_x < 20:
            self.vel_x = -self.vel_x

        if self.pos_y > 480 or self.pos_y < 20:
            self.vel_y = -self.vel_y
        self.pos_x += self.vel_x
        self.pos_y += self.vel_y
        pos = self.pos_x, self.pos_y
        pygame.draw.circle(screen, self.color, pos, self.radius, self.width)

pygame.init()
screen = pygame.display.set_mode((600, 500))
#   Circle实例
circle1 = Circle()

while True:
    for event in pygame.event.get():
        if event.type == QUIT:
            sys.exit()
        elif event.type == KEYUP:
            if event.key == pygame.K_1:
                circle1.change_circle(1)
            elif event.key == pygame.K_2:
                circle1.change_circle(2)
            elif event.key == pygame.K_3:
                circle1.change_circle(3)
            elif event.key == pygame.K_4:
                circle1.change_circle(4)

    screen.fill((0, 0, 100))

    circle1.circle_run()

    pygame.display.update()