game

- game.Load
  - game.Start
  - game.Loop
    - 初始化 wall,bean,goldBean,player,monster
    - 初始化 dir = dir_none
    - while(1)
      - key = GetKey() // 获取按键输入
      - switch(key)
        - p pause
        - q quit
        - w dir_up
        - s dir_down
        - a dir_left
        - d dir_right
        - other dir = last_dir
      - player.PlayerMove(wall,dir) // 玩家根据按键输入移动
        - player.NextMove(dir,nx,ny) //预测下一时刻玩家的坐标
        - 根据nx，ny，判断下一时刻玩家是否撞墙
          - be careful! you must have to ensure nx or ny is at last one is an integer, if not, you can't move according to the input direction
          - ofcourse, you can be a little tolerent, as an example, when the input direction wants to change ny, but nxis not an integer, but , maybe nx is so close to an integer, you can force it converting to an integer, and then change the ny
          - if you obey these rules, you can move the player,
          - player.Move(dir) //调用函数移动玩家
            - clear its image at the old (x,y),
            - then set the new (x,y) according( nx, ny), and draw its image at the new (x,y)
      - if(player.PlayerMove is successful) //如果上一时刻玩家成功移动（没撞墙）
        - player.TryEatBean(bean) // 玩家尝试吃豆子
          - include 2 parts ,first , judge player is or not meet a bean,
          - then, eat the bean and add player's score, and return true
        - if( successful) // 玩家尝试吃豆子成功
          - bean.IsEmpty? && goldBean.IsEmpty?
            - if(true)
              - game over, player win
        - player.TryEatGoldBean(goldBean)// 玩家尝试吃金豆子
          - include 2 parts, just same as above
        - if(successful) // 玩家尝试吃金豆子成功
          - bean.IsEmpty? && goldBean.IsEmpty?
            - if(true)
              - game over, player win
          - change all of monster's status
          - change all of monster's speed
      - monster.TryEatPlayer(player) //怪物尝试吃玩家
        - include 2 part, first, judge monster is or not meet the player,
        - then judge who is win according to monster's status , and (player win)change the player's score or (monster win) game over, player lose
      - monster.MonsterMove(wall,player)
        - according to monster.status, make different choice: chase or escape or waitingBorn
          - dir = chase(wall, player)
            - according to player.GetX & .GetY & wall, choose the move dir
          - dir = escape(wall, player)
            - get contrary dir by chase(wall,player)
          - dir = waitingBorn(wall)
          - monster.Move(dir)
            - clear its image at the old xy, then set the new xy according pre_x, pre_y, and draw its image at the new xy
            - just like what player.Move(dir) has done
          - 恢复地形
  - game.End