如何利用pygame实现简单的五子棋游戏

def main():
 pygame.init() #pygame初始化
 size = width,height = 544,544
 screen = pygame.display.set_mode(size, 0, 32)
 pygame.display.set_caption('五子棋')
 font = pygame.font.Font('simhei.ttf', 48)
 clock = pygame.time.Clock() #设置时钟
 game_over = False
 renju = Renju() # Renju是核心类，实现落子及输赢判断等
 renju.init() # 初始化

 while True:
 clock.tick(20) # 设置帧率
 for event in pygame.event.get():
 if event.type == pygame.QUIT:
 sys.exit()
 if event.type == pygame.MOUSEBUTTONDOWN and (not game_over):
 if event.button == 1: # 按下的是鼠标左键
  i,j = renju.get_coord(event.pos) # 将物理坐标转换成矩阵的逻辑坐标
  if renju.check_at(i, j): # 检查(i,j)位置能否被占用，如未被占用返回True
  renju.drop_at(i, j) # 在(i,j)位置落子，该函数将黑子或者白子画在棋盘上
  if renju.check_over(): # 检查是否存在五子连线，如存在则返回True
  text = ''
  if renju.black_turn: #check_at会切换落子的顺序，所以轮到黑方落子，意味着最后落子方是白方，所以白方顺利
  text = '白方获胜，游戏结束！'
  else:
  text = '黑方获胜，游戏结束！'
  gameover_text = font.render(text, True, (255,0,0))
  renju.chessboard().blit(gameover_text, (round(width/2-gameover_text.get_width()/2), round(height/2-gameover_text.get_height()/2)))
  game_over = True
  else:
  print('此位置已占用，不能在此落子')
 
 screen.blit(renju.chessboard(),(0,0))
 pygame.display.update()
 pygame.quit()

Position = namedtuple('Position', ['x', 'y'])

class Renju(object):
 
 background_filename = 'chessboard.png'
 white_chessball_filename = 'white_chessball.png'
 black_chessball_filename = 'black_chessball.png'
 top, left, space, lines = (20, 20, 36, 15) # 棋盘格子位置相关???
 color = (0, 0, 0) # 棋盘格子线颜色
 
 black_turn = True # 黑子先手
 ball_coord = [] # 记录黑子和白子逻辑位置
 
 def init(self):
 try:
 self._chessboard = pygame.image.load(self.background_filename)
 self._white_chessball = pygame.image.load(self.white_chessball_filename).convert_alpha()
 self._black_chessball = pygame.image.load(self.black_chessball_filename).convert_alpha()
 self.font = pygame.font.SysFont('arial', 16)
 self.ball_rect = self._white_chessball.get_rect()
 self.points = [[] for i in range(self.lines)]
 for i in range(self.lines):
 for j in range(self.lines):
  self.points[i].append(Position(self.left + i*self.space, self.top + j*self.space))
 self._draw_board()
 except pygame.error as e:
 print(e)
 sys.exit()
 
 def chessboard(self):
 return self._chessboard
 
 # 在(i,j)位置落子 
 def drop_at(self, i, j):
 pos_x = self.points[i][j].x - int(self.ball_rect.width/2)
 pos_y = self.points[i][j].y - int(self.ball_rect.height/2)

 ball_pos = {'type':0 if self.black_turn else 1, 'coord':Position(i,j)}
 if self.black_turn: # 轮到黑子下
 self._chessboard.blit(self._black_chessball, (pos_x, pos_y))
 else:
 self._chessboard.blit(self._white_chessball, (pos_x, pos_y)) 
 
 self.ball_coord.append(ball_pos) # 记录已落子信息
 self.black_turn = not self.black_turn # 切换黑白子顺序
 
 # 画棋盘上的格子线，如果棋盘背景图做的足够精确，可省略此步骤
 def _draw_board(self): 
 # 画坐标数字
 for i in range(1, self.lines):
 coord_text = self.font.render(str(i), True, self.color)
 self._chessboard.blit(coord_text, (self.points[i][0].x-round(coord_text.get_width()/2), self.points[i][0].y-coord_text.get_height()))
 self._chessboard.blit(coord_text, (self.points[0][i].x-coord_text.get_width(), self.points[0][i].y-round(coord_text.get_height()/2)))
 
 for x in range(self.lines):
 # 画横线
 pygame.draw.line(self._chessboard, self.color, self.points[0][x], self.points[self.lines-1][x])
 # 画竖线
 pygame.draw.line(self._chessboard, self.color, self.points[x][0], self.points[x][self.lines-1])
 
 # 判断是否已产生胜方
 def check_over(self):
 if len(self.ball_coord)>8: # 只有黑白子已下4枚以上才判断
 direct = [(1,0),(0,1),(1,1),(1,-1)] #横、竖、斜、反斜 四个方向检查
 for d in direct:
 if self._check_direct(d):
  return True
 return False
 
 # 判断最后一个棋子某个方向是否连成5子，direct:(1,0),(0,1),(1,1),(1,-1)
 def _check_direct(self, direct):
 dt_x, dt_y = direct 
 last = self.ball_coord[-1]
 line_ball = [] # 存放在一条线上的棋子
 for ball in self.ball_coord:
 if ball['type'] == last['type']:
 x = ball['coord'].x - last['coord'].x 
 y = ball['coord'].y - last['coord'].y
 if dt_x == 0:
  if x == 0:
  line_ball.append(ball['coord'])
  continue
 if dt_y == 0:
  if y == 0:
  line_ball.append(ball['coord'])
  continue
 if x*dt_y == y*dt_x:
  line_ball.append(ball['coord'])

 if len(line_ball) >= 5: # 只有5子及以上才继续判断
 sorted_line = sorted(line_ball)
 for i,item in enumerate(sorted_line): 
 index = i+4
 if index < len(sorted_line):
  if dt_x == 0:
  y1 = item.y
  y2 = sorted_line[index].y
  if abs(y1-y2) == 4: # 此点和第5个点比较y值，如相差为4则连成5子
  return True
  else:
  x1 = item.x
  x2 = sorted_line[index].x
  if abs(x1-x2) == 4: # 此点和第5个点比较x值，如相差为4则连成5子
  return True
 else:
  break
 return False
 
 # 检查(i,j)位置是否已占用 
 def check_at(self, i, j):
 for item in self.ball_coord:
 if (i,j) == item['coord']:
 return False
 return True
 
 # 通过物理坐标获取逻辑坐标 
 def get_coord(self, pos):
 x, y = pos
 i, j = (0, 0)
 oppo_x = x - self.left
 if oppo_x > 0:
 i = round(oppo_x / self.space) # 四舍五入取整
 oppo_y = y - self.top
 if oppo_y > 0:
 j = round(oppo_y / self.space)
 return (i, j)