Python实现打砖块小游戏

这次用Python实现的是一个接球打砖块的小游戏，需要导入pygame模块，有以下两条经验总结：

1.多父类的继承

2.碰撞检测的数学模型

知识点稍后再说，我们先看看游戏的效果和实现：

一、游戏效果

二、游戏代码

#导入模块
import pygame
from pygame.locals import *
import sys,random,time,mathclass GameWindow(object):'''创建游戏窗口类'''def __init__(self,*args,**kw):       self.window_length = 600self.window_wide = 500#绘制游戏窗口，设置窗口尺寸self.game_window = pygame.display.set_mode((self.window_length,self.window_wide))#设置游戏窗口标题pygame.display.set_caption("CatchBallGame")#定义游戏窗口背景颜色参数self.window_color = (135,206,250)def backgroud(self):#绘制游戏窗口背景颜色self.game_window.fill(self.window_color)class Ball(object):'''创建球类'''def __init__(self,*args,**kw):#设置球的半径、颜色、移动速度参数self.ball_color = (255,215,0)     self.move_x = 1self.move_y = 1self.radius = 10def ballready(self):#设置球的初始位置、self.ball_x = self.mouse_xself.ball_y = self.window_wide-self.rect_wide-self.radius#绘制球，设置反弹触发条件            pygame.draw.circle(self.game_window,self.ball_color,(self.ball_x,self.ball_y),self.radius)def ballmove(self):#绘制球，设置反弹触发条件           pygame.draw.circle(self.game_window,self.ball_color,(self.ball_x,self.ball_y),self.radius)      self.ball_x += self.move_xself.ball_y -= self.move_y#调用碰撞检测函数self.ball_window()self.ball_rect()#每接5次球球速增加一倍if self.distance < self.radius:self.frequency += 1if self.frequency == 5:self.frequency = 0self.move_x += self.move_xself.move_y += self.move_yself.point += self.point#设置游戏失败条件if self.ball_y > 520:self.gameover = self.over_font.render("Game Over",False,(0,0,0))self.game_window.blit(self.gameover,(100,130))self.over_sign = 1class Rect(object):'''创建球拍类'''def __init__(self,*args,**kw):#设置球拍颜色参数self.rect_color = (255,0,0)self.rect_length = 100self.rect_wide = 10def rectmove(self):#获取鼠标位置参数self.mouse_x,self.mouse_y = pygame.mouse.get_pos()#绘制球拍，限定横向边界                    if self.mouse_x >= self.window_length-self.rect_length//2:self.mouse_x = self.window_length-self.rect_length//2if self.mouse_x <= self.rect_length//2:self.mouse_x = self.rect_length//2pygame.draw.rect(self.game_window,self.rect_color,((self.mouse_x-self.rect_length//2),(self.window_wide-self.rect_wide),self.rect_length,self.rect_wide))class Brick(object):def __init__(self,*args,**kw):#设置砖块颜色参数self.brick_color = (139,126,102)self.brick_list = [[1,1,1,1,1,1],[1,1,1,1,1,1],[1,1,1,1,1,1],[1,1,1,1,1,1],[1,1,1,1,1,1]]self.brick_length = 80self.brick_wide = 20def brickarrange(self):        for i in range(5):for j in range(6):self.brick_x = j*(self.brick_length+24)self.brick_y = i*(self.brick_wide+20)+40if self.brick_list[i][j] == 1:#绘制砖块pygame.draw.rect(self.game_window,self.brick_color,(self.brick_x,self.brick_y,self.brick_length,self.brick_wide))                  #调用碰撞检测函数self.ball_brick()                                      if self.distanceb < self.radius:self.brick_list[i][j] = 0self.score += self.point#设置游戏胜利条件if self.brick_list == [[0,0,0,0,0,0],[0,0,0,0,0,0],[0,0,0,0,0,0],[0,0,0,0,0,0],[0,0,0,0,0,0]]:self.win = self.win_font.render("You Win",False,(0,0,0))self.game_window.blit(self.win,(100,130))self.win_sign = 1class Score(object):'''创建分数类'''def __init__(self,*args,**kw):       #设置初始分数self.score = 0#设置分数字体self.score_font = pygame.font.SysFont('arial',20)#设置初始加分点数self.point = 1#设置初始接球次数self.frequency = 0def countscore(self):#绘制玩家分数           my_score = self.score_font.render(str(self.score),False,(255,255,255))self.game_window.blit(my_score,(555,15))class GameOver(object):'''创建游戏结束类'''def __init__(self,*args,**kw):#设置Game Over字体self.over_font = pygame.font.SysFont('arial',80)#定义GameOver标识self.over_sign = 0class Win(object):'''创建游戏胜利类'''def __init__(self,*args,**kw):#设置You Win字体self.win_font = pygame.font.SysFont('arial',80)#定义Win标识self.win_sign = 0class Collision(object):'''碰撞检测类'''#球与窗口边框的碰撞检测def ball_window(self):if self.ball_x <= self.radius or self.ball_x >= (self.window_length-self.radius):self.move_x = -self.move_xif self.ball_y <= self.radius:self.move_y = -self.move_y#球与球拍的碰撞检测def ball_rect(self):#定义碰撞标识self.collision_sign_x = 0self.collision_sign_y = 0if self.ball_x < (self.mouse_x-self.rect_length//2):self.closestpoint_x = self.mouse_x-self.rect_length//2self.collision_sign_x = 1elif self.ball_x > (self.mouse_x+self.rect_length//2):self.closestpoint_x = self.mouse_x+self.rect_length//2self.collision_sign_x = 2else:self.closestpoint_x = self.ball_xself.collision_sign_x = 3if self.ball_y < (self.window_wide-self.rect_wide):self.closestpoint_y = (self.window_wide-self.rect_wide)self.collision_sign_y = 1elif self.ball_y > self.window_wide:self.closestpoint_y = self.window_wideself.collision_sign_y = 2else:self.closestpoint_y = self.ball_yself.collision_sign_y = 3#定义球拍到圆心最近点与圆心的距离self.distance = math.sqrt(math.pow(self.closestpoint_x-self.ball_x,2)+math.pow(self.closestpoint_y-self.ball_y,2))#球在球拍上左、上中、上右3种情况的碰撞检测if self.distance < self.radius and self.collision_sign_y == 1 and (self.collision_sign_x == 1 or self.collision_sign_x == 2):if self.collision_sign_x == 1 and self.move_x > 0:self.move_x = - self.move_xself.move_y = - self.move_yif self.collision_sign_x == 1 and self.move_x < 0:self.move_y = - self.move_yif self.collision_sign_x == 2 and self.move_x < 0:self.move_x = - self.move_xself.move_y = - self.move_yif self.collision_sign_x == 2 and self.move_x > 0:self.move_y = - self.move_yif self.distance < self.radius and self.collision_sign_y == 1 and self.collision_sign_x == 3:self.move_y = - self.move_y#球在球拍左、右两侧中间的碰撞检测if self.distance < self.radius and self.collision_sign_y == 3:self.move_x = - self.move_x#球与砖块的碰撞检测def ball_brick(self):#定义碰撞标识self.collision_sign_bx = 0self.collision_sign_by = 0if self.ball_x < self.brick_x:self.closestpoint_bx = self.brick_xself.collision_sign_bx = 1elif self.ball_x > self.brick_x+self.brick_length:self.closestpoint_bx = self.brick_x+self.brick_lengthself.collision_sign_bx = 2else:self.closestpoint_bx = self.ball_xself.collision_sign_bx = 3if self.ball_y < self.brick_y:self.closestpoint_by = self.brick_yself.collision_sign_by = 1elif self.ball_y > self.brick_y+self.brick_wide:self.closestpoint_by = self.brick_y+self.brick_wideself.collision_sign_by = 2else:self.closestpoint_by = self.ball_yself.collision_sign_by = 3#定义砖块到圆心最近点与圆心的距离self.distanceb = math.sqrt(math.pow(self.closestpoint_bx-self.ball_x,2)+math.pow(self.closestpoint_by-self.ball_y,2))#球在砖块上左、上中、上右3种情况的碰撞检测if self.distanceb < self.radius and self.collision_sign_by == 1 and (self.collision_sign_bx == 1 or self.collision_sign_bx == 2):if self.collision_sign_bx == 1 and self.move_x > 0:self.move_x = - self.move_xself.move_y = - self.move_yif self.collision_sign_bx == 1 and self.move_x < 0:self.move_y = - self.move_yif self.collision_sign_bx == 2 and self.move_x < 0:self.move_x = - self.move_xself.move_y = - self.move_yif self.collision_sign_bx == 2 and self.move_x > 0:self.move_y = - self.move_yif self.distanceb < self.radius and self.collision_sign_by == 1 and self.collision_sign_bx == 3:self.move_y = - self.move_y#球在砖块下左、下中、下右3种情况的碰撞检测if self.distanceb < self.radius and self.collision_sign_by == 2 and (self.collision_sign_bx == 1 or self.collision_sign_bx == 2):if self.collision_sign_bx == 1 and self.move_x > 0:self.move_x = - self.move_xself.move_y = - self.move_yif self.collision_sign_bx == 1 and self.move_x < 0:self.move_y = - self.move_yif self.collision_sign_bx == 2 and self.move_x < 0:self.move_x = - self.move_xself.move_y = - self.move_yif self.collision_sign_bx == 2 and self.move_x > 0:self.move_y = - self.move_yif self.distanceb < self.radius and self.collision_sign_by == 2 and self.collision_sign_bx == 3:self.move_y = - self.move_y#球在砖块左、右两侧中间的碰撞检测if self.distanceb < self.radius and self.collision_sign_by == 3:self.move_x = - self.move_xclass Main(GameWindow,Rect,Ball,Brick,Collision,Score,Win,GameOver):'''创建主程序类'''def __init__(self,*args,**kw):       super(Main,self).__init__(*args,**kw)super(GameWindow,self).__init__(*args,**kw)super(Rect,self).__init__(*args,**kw)super(Ball,self).__init__(*args,**kw)super(Brick,self).__init__(*args,**kw)super(Collision,self).__init__(*args,**kw)      super(Score,self).__init__(*args,**kw)super(Win,self).__init__(*args,**kw)#定义游戏开始标识start_sign = 0while True:           self.backgroud()self.rectmove()self.countscore()            if self.over_sign == 1 or self.win_sign == 1:break#获取游戏窗口状态for event in pygame.event.get():if event.type == pygame.QUIT:sys.exit()if event.type == MOUSEBUTTONDOWN:pressed_array = pygame.mouse.get_pressed()if pressed_array[0]:start_sign = 1if start_sign == 0:self.ballready()else:self.ballmove()self.brickarrange()#更新游戏窗口pygame.display.update()#控制游戏窗口刷新频率time.sleep(0.010)if __name__ == '__main__':pygame.init()pygame.font.init()catchball = Main()

三、知识点

1.多父类的继承

Python的继承方式分为深度优先和广度优先，Python2分经典类的深度优先搜索继承方式（class A:）、新式类的广度优先搜索继承方式（class A(object):）2种，Python3经典类与新式类的继承方式与python2的新式类继承方式一致，都为广度优先的继承方式。

经典类的深度优先搜索继承方式：

如图所示
class B(A)
class C(A)
class D(B,C)

（1）若D类有构造函数，则重写所有父类的继承
（2）若D类没有构造函数，B类有构造函数，则D类会继承B类的构造函数
（3）若D类没有构造函数，B类也没有构造函数，则D类会继承 A类的构造函数，而不是C类的构造函数
（4）若D类没有构造函数，B类也没有构造函数，A类也没有构造函数，则D类才会继承C类的构造函数

新式类的广度优先搜索继承方式：

如图所示
class B(A)
class C(A)
class D(B,C)

（1）若D类有构造函数，则重写所有父类的继承
（2）若D类没有构造函数，B类有构造函数，则D类会继承B类的构造函数
（3）若D类没有构造函数，B类也没有构造函数，则D类会继承 C类的构造函数，而不是A类的构造函数
（4）若D类没有构造函数，B类也没有构造函数，C类也没有构造函数，则D类才会继承A类的构造函数

通过上面的分析，大家应该清楚了Python中类的继承顺序，那么问题来了，如果我不想重写父类的构造函数，要子类和父类的构造函数都生效怎么办？解决办法需要用到super关键字，对直接父类对象的引用,可以通过super来访问父类中被子类覆盖的方法或属性。

class A(object):def __init__(self,*args,**kw)
class B(A):def __init__(self,*args,**kw)super(B,self).__init__(*args,**kw)
class C(A):def __init__(self,*args,**kw)super(C,self).__init__(*args,**kw)
class D(B,C):def __init__(self,*args,**kw)super(D,self).__init__(*args,**kw)super(B,self).__init__(*args,**kw)

2.碰撞检测的数学模型

其实，编程问题到最后就是数学问题，这个游戏涉及到2D圆形与矩形的碰撞检测问题：

碰撞检测原理：通过找出矩形上离圆心最近的点，然后通过判断该点与圆心的距离是否小于圆的半径，若小于则为碰撞。

那如何找出矩形上离圆心最近的点呢？下面我们从 x 轴、y 轴两个方向分别进行寻找。为了方便描述，我们先约定以下变量：

（1）矩形上离圆心最近的点为变量：closestpoint = [x, y]
（2）矩形 rect = [x, y, l, w] 左上角与长宽 length,wide
（3）圆形 circle = [x, y, r] 圆心与半径

首先是 x 轴：
如果圆心在矩形的左侧（if circle_x < rect_x），那么 closestpoint_x = rect_x。
如果圆心在矩形的右侧（elif circle_x > rect_x + rect_l），那么 closestpoint_x = rect_x + rect_l。
如果圆心在矩形的正上下方（else），那么 closestpoint_x = circle_x。

同理，对于 y 轴：
如果圆心在矩形的上方（if circle_y < rect_y），那么 closestpoint_y = rect_y。
如果圆心在矩形的下方（elif circle_y > rect_y + rect_w)），那么 closestpoint_y = rect_y + rect_w。
圆形圆心在矩形的正左右两侧（else），那么 closestpoint_y = circle_y。

因此，通过上述方法即可找出矩形上离圆心最近的点了，然后通过“两点之间的距离公式”得出“最近点”与“圆心”的距离，最后将其与圆的半径相比，即可判断是否发生碰撞。
distance=math.sqrt(math.pow(closestpoint_x-circle_x,2)+math.pow(closestpoint_y-circle_y,2))

if distance < circle.r :
return True – 发生碰撞
else :
return False – 未发生碰撞