双人弹小球

#include <conio.h>
#include <graphics.h>
#include<windows.h>
#define High 480  // 游戏画面尺寸
#define Width 640
// 全局变量
int ball_x, ball_y; // 小球的坐标
int ball_vx, ball_vy; // 小球的速度
int radius; // 小球的半径
int bar1_left, bar1_right, bar1_top, bar1_bottom; // 挡板1的上下左右位置坐标
int bar2_left, bar2_right, bar2_top, bar2_bottom; // 挡板2的上下左右位置坐标
int bar_height, bar_width; // 挡板的高度、宽度

void startup()  // 数据初始化
{
  ball_x = Width / 2;
  ball_y = High / 2;
  ball_vx = 1;
  ball_vy = 1;
  radius = 20;

  bar_width = Width / 30;
  bar_height = High / 2;

  bar1_left = Width * 1 / 20;
  bar1_top = High / 4;
  bar1_right = bar1_left + bar_width;
  bar1_bottom = bar1_top + bar_height;

  bar2_left = Width * 18.5 / 20;
  bar2_top = High / 4;
  bar2_right = bar2_left + bar_width;
  bar2_bottom = bar2_top + bar_height;

  initgraph(Width, High);
  BeginBatchDraw();
}

void clean()  // 消除画面
{
  setcolor(BLACK);
  setfillcolor(BLACK);
  fillcircle(ball_x, ball_y, radius);
  fillcircle(ball_x, ball_y, radius);
  bar(bar1_left, bar1_top, bar1_right, bar1_bottom);
  bar(bar2_left, bar2_top, bar2_right, bar2_bottom);
}

void show()  // 显示画面
{
  setcolor(GREEN);
  setfillcolor(GREEN);
  fillcircle(ball_x, ball_y, radius); // 绘制绿圆 

  setcolor(YELLOW);
  setfillcolor(YELLOW);
  bar(bar1_left, bar1_top, bar1_right, bar1_bottom);  // 绘制黄色挡板
  bar(bar2_left, bar2_top, bar2_right, bar2_bottom);

  FlushBatchDraw();
  // 延时
  Sleep(1);
}

void updateWithoutInput()  // 与用户输入无关的更新
{
  // 挡板和小圆碰撞，小圆反弹
  if (ball_x + radius >= bar2_left && ball_y + radius >= bar2_top && ball_y + radius <= bar2_bottom)
    ball_vx = -ball_vx;
  else if (ball_x - radius <= bar1_right && ball_y + radius >= bar1_top && ball_y + radius <= bar1_bottom)
    ball_vx = -ball_vx;

  // 更新小圆坐标
  ball_x = ball_x + ball_vx;
  ball_y = ball_y + ball_vy;

  if ((ball_x <= radius) || (ball_x >= Width - radius))
    ball_vx = -ball_vx;
  if ((ball_y <= radius) || (ball_y >= High - radius))
    ball_vy = -ball_vy;
}

void updateWithInput()  // 与用户输入有关的更新
{
  int step = 1;
  if (GetAsyncKeyState(0x57) & 0x8000)  // w
    bar1_top -= step;
  if ((GetAsyncKeyState(0x53) & 0x8000)) //s
    bar1_top += step;
  if ((GetAsyncKeyState(VK_UP) & 0x8000))     // 上方向键
    bar2_top -= step;
  if ((GetAsyncKeyState(VK_DOWN) & 0x8000))  // 下方向键
    bar2_top += step;

  bar1_bottom = bar1_top + bar_height;
  bar2_bottom = bar2_top + bar_height;
}

void gameover()
{
  EndBatchDraw();
  closegraph();
}

int main()
{
  startup();  // 数据初始化  
  while (1)  //  游戏循环执行
  {
    clean();  // 把之前绘制的内容取消
    updateWithoutInput();  // 与用户输入无关的更新
    updateWithInput();     // 与用户输入有关的更新
    show();  // 显示新画面
  }
  gameover();     // 游戏结束、后续处理
  return 0;
}