Python游戏开发-06-玩个球(PlayTheBall)开发笔记01-基本功能

面向对象游戏开发。含背景，球的初始化，边界检测，碰撞检测（自己写的，未用提供的函数）

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

class Ball(pygame.sprite.Sprite):
    def __init__(self,image,position,speed,bg_size):
        pygame.sprite.Sprite.__init__(self)

        self.image = pygame.image.load(image).convert_alpha()
        self.rect = self.image.get_rect()
        self.rect.left,self.rect.top = position
        self.speed = speed
        self.width,self.height = bg_size[0],bg_size[1]

    def move(self):
        self.rect = self.rect.move(self.speed)

        #边界检测 穿越式
        if self.rect.right < 0:
            self.rect.left = self.width

        elif self.rect.left > self.width:
            self.rect.right = 0

        elif self.rect.bottom < 0:
            self.rect.top = self.height

        elif self.rect.top > self.height:
            self.rect.bottom = 0


#碰撞检测函数
def collide_check(item,target):#item是一个球,target是其他球的列表
    col_balls = []#存放碰撞的球
    for each in target:
        distance = math.sqrt(\
            math.pow((item.rect.center[0]-each.rect.center[0]),2) +\
            math.pow((item.rect.center[1]-each.rect.center[1]),2)
            ) #开根号[(x1-x2)^2+(y1-y2)^2]
        if distance <= (item.rect.width+each.rect.width)/2:
            col_balls.append(each)

    return col_balls #返回和item碰撞的球    
            
                   
def main():
    pygame.init()

    ball_image = "gray_ball.png"
    bg_image = "background.png"

    running = True

    bg_size = width,height = 638,508
    screen = pygame.display.set_mode(bg_size)
    pygame.display.set_caption("玩个球")
    background = pygame.image.load(bg_image).convert_alpha()

    balls = []

    BALL_NUM = 5
    for i in range(BALL_NUM):
        position = randint(0,width-66),randint(0,height-66)
        speed = [randint(-10,10),randint(-10,10)]

        ball = Ball(ball_image,position,speed,bg_size)

        #防止出现两个球来回抖啊抖
        while collide_check(ball,balls):
            ball.rect.left,ball.rect.top = randint(0,width-66),randint(0,height-66)

            
        balls.append(ball)

    clock = pygame.time.Clock()
        
    while running:
        for event in pygame.event.get():
            if event.type == QUIT:
                sys.exit()

        screen.blit(background,(0,0))

        for each in balls:
            each.move()
            screen.blit(each.image, each.rect)

        for i in range(BALL_NUM):
            #把i先取出来，因为他肯定和自己碰撞
            item = balls.pop(i)
            if collide_check(item,balls):
                item.speed[0]=-item.speed[0]
                item.speed[1]=-item.speed[1]

            #i取出来得再放进去
            balls.insert(i,item)
            
        pygame.display.flip()
        clock.tick(30)

if __name__ == "__main__":
    main()