java实现小球碰撞功能

Z时代
2024-01-10
分类：综合

本文实例为大家分享了java实现小球碰撞的具体代码，供大家参考，具体内容如下

这次我们做一个小球的碰撞的游戏，规则是：按下添加按钮，窗口的中心部分会产生一个小球（刚开始默认为黑色），四个方向随机产生，发射小球，再次按下即产生两个小球。当小球碰到窗体边缘的时候会产生反弹，当两个小球接触时会产生碰撞，双方交换速度，向相反方向移动。我们可以选择相应的颜色来改变下一个发射的小球颜色。当按下清除可以清除屏幕上的小球，当按下添加则会继续产生小球。最后我们还添加了自动产生小球的功能，按下开关，在屏幕中间会定时产生小球。接下来，我们来展示代码部分。


public class Jframe {
 private Ball[] arrayball = new Ball[100];
 public static void main(String[] args) {
 Jframe frame = new Jframe();
 frame.showUI();
 }
 public void showUI() {
 javax.swing.JFrame jf = new javax.swing.JFrame();
 jf.setSize(1000, 1000);
 jf.getContentPane().setBackground(Color.WHITE);
 jf.setTitle("小球");
 jf.setDefaultCloseOperation(3);
 // 设置居中显示
 jf.setLocationRelativeTo(null);
 JPanel jp1 =new JPanel(); 
 JButton jb1 = new JButton("添加");
 jp1.add(jb1);
 // jb1.setBounds(100,50, 40, 20);
 JButton jb2 = new JButton("暂停");
 jp1.add(jb2);
 // jb1.setBounds(200,50, 40, 20);
 JButton jb3 = new JButton("清除");
 jp1.add(jb3);
 // jb1.setBounds(300,50, 40, 20);
 JButton jb4 = new JButton("自动添加");
 jp1.add(jb4); 
 jf.add(jp1,BorderLayout.NORTH); 
  Mouse mouse = new Mouse();  
 Color[] color = {Color.RED,Color.BLUE,Color.BLACK,Color.GREEN,Color.YELLOW};
 for(int i=0;i<color.length;i++){
 JButton jbu = new JButton();
 jbu.setBackground(color[i]);
 jbu.setPreferredSize(new Dimension(30, 30));
 jp1.add(jbu);
 jbu.addActionListener(mouse);
 } 
 jb1.addActionListener(mouse);
 jb2.addActionListener(mouse);
 jb3.addActionListener(mouse);
 jb4.addActionListener(mouse);
 jf.addMouseListener(mouse);
 jf.addMouseMotionListener(mouse);
 BallJpanel cp = new BallJpanel(); 
 cp.setBackground(Color.WHITE);
 jf.add(cp,BorderLayout.CENTER);
 jf.setVisible(true);   
 Graphics g = cp.getGraphics();
 mouse.setcp(cp); 
 mouse.setg(g);
 mouse.setarrayball(arrayball);
 mouse.setmouse(mouse);
 cp.setarrayball(arrayball); 
 }
}

这是窗体的基本配置，采用边框布局，上方放置按钮，中间是画布。我们为按钮添加了动作监听器，并使用了一系列的方法来把对象传递到其他类中。


public class Ball {
 public int size = 90; // 小球的直径
 public int x = 500; // 小球所在的x坐标
 public int y = 500; // 小球所在的y坐标
 public int vx = 5;
 public int vy = 5;
 public BallJpanel cp;
 public Color color = Color.BLACK;
 public int max_x, max_y, Min_x, Min_y;
 private Ball[] arrayball;
 public void setcp(BallJpanel cp) {
 this.cp = cp;
 }
 public void setarrayball(Ball[] arrayball) {
 this.arrayball = arrayball;
 }
 public void setX(int x) {
 this.x = x;
 }
 public int getX() {
 return x;
 }
 public void setY(int y) {
 this.y = y;
 }
 public int setY() {
 return y;
 }
 public Ball(int x, int y, int vx, int vy, Color color) {
 this.x = x;
 this.y = y;
 this.vx = vx;
 this.vy = vy;
 this.color = color;
 }
 public void ballMove(Graphics g) {
 x += vx;
 y += vy;
 max_y = cp.getHeight();
 max_x = cp.getWidth();
 if (x <= size / 2) {
 x = size / 2;
 vx = -vx;
 }
 if (y <= size / 2) {
 y = size / 2;
 vy = -vy;
 }
 if (x + size / 2 >= max_x) {
 x = max_x - size / 2;
 vx = -vx;
 }
 if (y + size / 2 >= max_y) {
 y = max_y - size / 2;
 vy = -vy;
 }
 for (int i = 0; i < arrayball.length; i++) 
 {
 if (arrayball[i] == null)
 break;
 Ball ball = arrayball[i];
 if (this.equals(ball))
 continue;
 if ((ball.x - this.x) * (ball.x - this.x) + (ball.y - this.y) * (ball.y - this.y) <= size * size)
 {
 int tempvx = this.vx;
 int tempvy = this.vy;
 this.vx = ball.vx;
 this.vy = ball.vy;
 ball.vx = tempvx;
 ball.vy = tempvy;
 while ((ball.x - this.x) * (ball.x - this.x) + (ball.y - this.y) * (ball.y - this.y) <= size * size)
 {
  this.x += this.vx;
  this.y += this.vy;
  System.out.println("等待");
 }
 }
 }
 }
}

考虑到这是一个小球的运动系统，我们为小球写了一个类，添加小球的时候，会创建小球对象，并使其获得位置，颜色，速度等参数，并将其存入数组。小球的方法就是运动，每当执行ballMove方法，便会为小球修改位置坐标（基于其速度），再判断是否撞击边框，以及判断是否和别的小球有坐标重叠，如果有重叠，则跑一个循环，修改位置坐标，使其分离。Ball这部分代码和监听器中的方法有所联系，我们接下来介绍监听器的方法。


public class Mouse implements MouseMotionListener, MouseListener, ActionListener {
 private Graphics g;
 private BallJpanel cp;
 private Ball[] arrayball;
 private int index = 0;
 private int x;
 private int y;
 private int vx;
 private int vy;
 private int random=1;
 private Color color=Color.black;
 private ThreadBall tb;
 private Mouse mouse;
 public int selfFlag=0;
 public void setmouse(Mouse mouse)
 {
  this.mouse= mouse;
 } 
 public void setarrayball(Ball[] arrayball) {
 this.arrayball = arrayball;
 }
 public void setg(Graphics g) {
 this.g = g;
 }
 public void setcp(BallJpanel cp) {
 this.cp = cp;
 }
 public void actionPerformed(ActionEvent e) { 
 if ("添加".equals(e.getActionCommand())) {
 System.out.println("添加");
 if (tb == null) {
 // 创建线程对象
 tb = new ThreadBall();
 tb.setcp(cp);
 tb.setarrayball(arrayball);
 tb.setg(g);
 tb.start();
 tb.setmouse(mouse);
 }
 tb.stopFlag=0;
 addBall(); 
 }
 if ("暂停".equals(e.getActionCommand())) { 
 if(tb!=null)
 {
  if(tb.stopFlag==0)
  {
   tb.stopFlag=1;
   System.out.println("暂停");
  }
  else 
  {
  tb.stopFlag=0;
  System.out.println("开始");
  }
 } 
 }
 if ("清除".equals(e.getActionCommand())) {
 tb.stopFlag=1;
 cp.paint1(g);
 index=0;
 System.out.println("清除");
 }
 if ("自动添加".equals(e.getActionCommand())){
 if(selfFlag==0)
 {selfFlag=1;System.out.println("自动添加打开");}
 else
 {selfFlag=0;System.out.println("自动添加关闭");} 
 }  
 if("".equals(e.getActionCommand())){
 JButton jbu=(JButton)e.getSource();
 color=jbu.getBackground();
 g.setColor(color); 
 }
 }
 public void mouseDragged(MouseEvent e) {
 }
 public void mouseMoved(MouseEvent e) {
 }
 public void mouseClicked(MouseEvent e) {
 }
 public void mousePressed(MouseEvent e) {
 }
 public void mouseReleased(MouseEvent e) {
 }
 public void mouseEntered(MouseEvent e) {
 }
 public void mouseExited(MouseEvent e) {
 }
 public void addBall() {
 x = 500;
 y = 500;
 random=1+(int)(Math.random()*4);
 switch(random)
 {
 case 1:
 vx=5;
 vy=5;
 break;
 case 2:
 vx=-5;
 vy=-5; 
 break;
 case 3:
 vx=5;
 vy=-5; 
 break;
 case 4:
 vx=-5;
 vy=5; 
 break; 
 }
 Ball ball = new Ball(x, y,vx , vy, color); 
 arrayball[index++] = ball;
 }
}

监听器中，我们设置了一系列参数来控制一些方法的开启和关闭，以及写了添加小球的方法，为其赋初值，随机一个初始发射方向。这段代码我们用到了线程。线程的使用分为两步，创建线程对象并start线程。


public class ThreadBall extends Thread {
 private Graphics g;
 private BallJpanel cp;
 private Ball[] arrayball;
 public int stopFlag=0;
 private int add=0;
 private Mouse mouse;
 public void setmouse(Mouse mouse)
 {
 this.mouse=mouse;
 } 
 public void setcp(BallJpanel cp) {
 this.cp = cp; 
 }
 public void setg(Graphics g)
 {
 this.g=g;
 } 
 public void setarrayball(Ball[] arrayball) {
 this.arrayball = arrayball;
 }
 /**
 * 启动线程执行的方法
 */
 public void run() {
 while (true) {
   if(stopFlag==0)
   {
  for (int i = 0; i < arrayball.length; i++) 
  {
  if(arrayball[i]==null)
  break; 
   Ball ball = arrayball[i];    
    ball.setarrayball(arrayball);   
  ball.setcp(cp);
  ball.ballMove(g);   
  } 
  cp.paint(g);
  add++;
  if(add==5000)
  add=0;
  if(add%50==0&&mouse.selfFlag==1)
  mouse.addBall();
   }
  try {
  Thread.sleep(50);
  } catch (InterruptedException e) {
  e.printStackTrace();
  }   
 }
 }
}

以上是线程的属性和方法，此类继承Thread并重写了run方法。run方法的思路是循环调用ballMove方法修改小球坐标，并调用paint方法更新显示，我们加入了一个延时函数，来控制调用的频率。


public class BallJpanel extends JPanel { 
 private Ball[] arrayball; 
 public void setarrayball(Ball[] arrayball)
 {
 this.arrayball=arrayball;
 } 
 public void paint(Graphics g)
 {
 super.paint(g); 
 for(int i=0;i<arrayball.length;i++)
 {
 if(arrayball[i]==null)
 {
 break; 
 }
 Ball ball=arrayball[i];
 g.setColor(ball.color);
 g.fillOval(ball.x-ball.size/2, ball.y-ball.size/2, ball.size, ball.size);
 }
 } 
 public void paint1(Graphics g)
 {
 super.paint(g); 
 for(int i=0;i<arrayball.length;i++)
 {
 if(arrayball[i]==null)
 {
 break; 
 }
 arrayball[i]=null; 
 }
 } 
}