/*
 * 基于curses库弹球游戏，编译gcc xxx.c -lcurses
 */
#include <curses.h>
#include <sys/time.h>
#include <signal.h>
  
#define RIGHT COLS-1  /*球所能到达的当前屏幕最大水平范围*/
#define BOTTOM LINES-1 /*球所能到达的当前屏幕最大垂直范围*/
#define BOARD_LENGTH  10 /*挡板长度*/
#define LEFT 0 /*当前屏幕的最左边*/
#define TOP 0  /*当前屏幕的最上边*/
char BALL= 'O'; /*球的形状*/
char BLANK= ' '; /*覆盖球走过的轨迹*/
  
  
int left_board; /*挡板左侧坐标*/
int right_board; /*挡板右侧坐标*/
int is_lose=0;
  
  
int hdir;  /*控制球水平运动的变量*/
int vdir;  /*控制球垂直运动的变量*/
int pos_X; /*球的横坐标*/
int pos_Y; /*球的纵坐标*/
    
int delay=100;
void moveBall();
void init();
void control();
  
int main()
{
  //初始化 curses
  initscr();
  crmode(); /*中断模式*/
  noecho(); /*关闭回显*/
    
  move(6,28);
  attron(A_BOLD);
  addstr("Welcome to the BallGame!");
  move(8,20);
  attroff(A_BOLD);
  addstr("Help:");
  move(9,23);
  addstr("'N':Start a new game.");
  move(10,23);
  addstr("'Q':Quit game.");
  move(11,23);
  addstr("'KEY_LEFT' :Control baffle left shift.");
  move(12,23);
  addstr("'KEY_RIGHT':Control baffle right shift.");
  move(13,23);
  addstr("'KEY_UP'  :Control of the ball speed.");
  move(14,23);
  addstr("'KEY_DOWN' :Control of the ball reducer.");
  int flag=1;
  char choice;
  move(16,24);
  addstr("Please choose your choice!(n/q):");
  refresh();
  choice=getch();
  while(flag){
    if(choice=='q'||choice=='Q'||choice=='n'||choice=='N')
       flag=0;
    else choice=getch();
  }
  if(choice=='n'||choice=='N'){  /*开始游戏*/
    clear();
    move(10,25);
    addstr("BallGame will start! Are you read?");
    refresh();
    sleep(3);
    control();
  }
  else if(choice=='q'||choice=='Q'){  /*退出游戏*/
    clear();
    move(10,25);
    addstr("You quit the game successfully!");
    refresh();
    sleep(3);
    endwin();
  }
  endwin(); /*结束 curses*/
  return 0;
}
  
void init(){
  int i,j;
  clear();
  if(start_color()==OK){ /*改变球和挡板的颜色*/
    attron(A_BOLD); /*打开粗体*/
    init_pair(1,COLOR_YELLOW,COLOR_BLACK);
    attron(COLOR_PAIR(1));
  }
  //初始球
  pos_X =22; /*球初始的横坐标*/
  pos_Y = BOTTOM-1; /*球初始的纵坐标*/
  //初始化球的运动方向,朝右上方运动
  hdir=1; 
  vdir=-1;
  
  //初始挡板
  left_board=20;
  right_board=left_board+BOARD_LENGTH;
  for(i=left_board;i<=right_board;i++){ /*显示挡板*/
    move(BOTTOM,i);
    addch('-');
  }
  
  //初始刷新时间
  signal(SIGALRM,moveBall);
  set_ticker(delay);
  
  keypad(stdscr,TRUE); /*打开 keypad 键盘响应*/
  attroff(A_BLINK);   /*关闭 A_BLINK 属性*/
    
  is_lose=0;
  move(pos_Y,pos_X);
  addch(BALL);
  move(LINES-1, COLS-1);
  refresh();
  usleep(100000); /*睡眠*/
  move(LINES-1,COLS-1);
  refresh();
}
  
void moveBall(){
  if(is_lose) return;
  signal(SIGALRM,moveBall);
  move(pos_Y,pos_X);
  addch(BLANK);
  pos_X += hdir;
  pos_Y += vdir;
  //改变球的方向时
  if(pos_X >= RIGHT) { /*当球横坐标大于右边边缘时，球反弹朝左运动*/
    hdir = -1;
    beep();  /*球撞墙时，发出声音*/
  }
  if(pos_X <= LEFT) { /*当球横坐标大于左边边缘时，球反弹朝右运动*/
    hdir = 1;
    beep(); /*球撞墙时，发出声音*/
  }
  if(pos_Y <= TOP)  { /*当球纵坐标大于顶部边缘时，球反弹朝下运动*/
    vdir = 1;
    beep(); /*球撞墙时，发出声音*/
  }
  
  //当球在底部的时候进行额外的处理
  if(pos_Y >= BOTTOM-1){
    if(pos_X>=left_board&&pos_X<=right_board) /*球在挡板处*/
      vdir=-1;
    else{  /*球不在挡板处*/
      is_lose=1;
      move(pos_Y,pos_X);
      addch(BALL);
      move(LINES-1, COLS-1);
      refresh();
      usleep(delay*1000); /*睡眠*/
      move(pos_Y,pos_X);
      addch(BLANK);
      pos_X += hdir;
      pos_Y += vdir;
      move(pos_Y,pos_X);
      addch(BALL);
      move(LINES-1, COLS-1);
      refresh();
    }
  }
  //不改变球的方向时
  move(pos_Y,pos_X);
  addch(BALL);
  move(LINES-1, COLS-1);
  refresh();
}
void control(){
  init();
  int cmd;
  while (1)
  {   
    if(!is_lose){
      cmd=getch();
      if(cmd=='q'||cmd=='Q'||cmd==27) break; //强制退出游戏
      //挡板左移
      if(cmd==KEY_LEFT){
        if(left_board>0){
          move(BOTTOM,right_board);
          addch(' ');
          right_board--;
          left_board--;           
          move(BOTTOM,left_board);
          addch('-');
          move(BOTTOM,RIGHT);
          refresh();
        }
      }   
      //挡板右移
      else if(cmd==KEY_RIGHT){
        if(right_board<RIGHT){
          move(BOTTOM,left_board);
          addch(' ');
          right_board++;
          left_board++;
          move(BOTTOM,right_board);
          addch('-');
          move(BOTTOM,RIGHT);
          refresh();
        }
      }
      //给球加速
      else if(cmd==KEY_UP){  
        delay/=2;   
        set_ticker(delay);
      }
      //给球减速
      else if(cmd==KEY_DOWN){ 
        delay*=2;
        set_ticker(delay);
      }
      
    }
    else{
      //输掉球后的处理
      int flag=1;
      char choice;
      move(8,15);
      addstr("Game Over!try again?(y/n):");
      refresh();
      choice=getch();
  
      while(flag){
        if(choice=='y'||choice=='Y'||choice=='n'||choice=='N')
           flag=0;
        else choice=getch();
      }
      if(choice=='y'||choice=='Y'){ /*游戏重新开始*/
          delay=100; /*恢复球的初始速度*/
          init();
          continue;
      }
      else if(choice=='n'||choice=='N'){  /*结束游戏*/
          break;
      }
    }
  }
}
//设置定时器
int set_ticker(int n_msecs){
  struct itimerval new_timeset;   
  long n_sec,n_usecs;
  n_sec=n_msecs/1000;
  n_usecs=(n_msecs%1000)*1000L;
  new_timeset.it_interval.tv_sec=n_sec;
  new_timeset.it_interval.tv_usec=n_usecs;
  new_timeset.it_value.tv_sec=n_sec;
  new_timeset.it_value.tv_usec=n_usecs;
  return setitimer(ITIMER_REAL,&new_timeset,NULL); 
}