弹跳线碰撞

Question

    import java.awt.Color;
    import java.awt.Graphics2D;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;
    import java.util.Random;

    import javax.swing.Timer;

    public class BouncingLinesWithSound implements ActionListener
    {
      private Random rand = new Random();
      private Timer myTimer;
      private Picture myPic;

      //TODO: Changed form Graphics
      private Graphics2D canvas;

      //TODO: Requires SoundPlayer.java to be in same project src folder as this file
      private SoundPlayer boinkSound;

      private static final int DRAW_WIDTH = 600;
      private static final int DRAW_HEIGHT = 600;

      private int x1, y1, x2, y2;
      private int x3, y3, x4, y4;
      private int speedX1, speedX2, speedY1, speedY2;
      private int speedX3, speedX4, speedY3, speedY4;



      //////////////////////////////////////////////////////////////////////
      // BouncingLine Constructor. This constructor:
      // 1) Creates an empty Picture Frame
      // 2) Sets the initial location, and speed of each end point of a line.
      // 3) Start the timer.
      /////////////////////////////////////////////////////////////////////
      public BouncingLinesWithSound() 
      {
        myPic = new Picture(DRAW_WIDTH, DRAW_HEIGHT);

    //TODO
    //If you want a Graphics2D rather than a graphics, just cast 
    //  the value returned by myPic.getOffScreenGraphics()
    canvas = (Graphics2D)myPic.getOffScreenGraphics();

    canvas.setColor(Color.WHITE);
    canvas.fillRect(0, 0, DRAW_WIDTH, DRAW_HEIGHT);

    myPic.setTitle("Bouncing Line");


    x1 = rand.nextInt(DRAW_WIDTH);
    y1 = rand.nextInt(DRAW_HEIGHT);
    x2 = rand.nextInt(DRAW_WIDTH);
    y2 = rand.nextInt(DRAW_HEIGHT);
    x3 = rand.nextInt(DRAW_WIDTH);
    y3 = rand.nextInt(DRAW_HEIGHT);
    x4 = rand.nextInt(DRAW_WIDTH);
    y4 = rand.nextInt(DRAW_HEIGHT);

    speedX1 = rand.nextInt(25)-12;
    speedY1 = rand.nextInt(25)-12;
    speedX2 = rand.nextInt(25)-12;
    speedY2 = rand.nextInt(25)-12;
    speedX3 = rand.nextInt(25)-12;
    speedY3 = rand.nextInt(25)-12;
    speedX4 = rand.nextInt(25)-12;
    speedY4 = rand.nextInt(25)-12;




    ////////////////////////////////////////////
    try
    {
      boinkSound = new SoundPlayer();
    }
    catch (Exception e)
    {
      System.out.println("BouncingLinesWithSound():: "+e.getMessage());
      System.exit(0);
    }

    myTimer = new Timer(30, this); // miliseconds
    myTimer.start();

  }





  ///////////////////////////////////////////////////////////////////////
  // Called each time the timer fires.
  // 1) Erase the current line
  // 2) Move the two end points of the line.
  // 3) Check to see if either end point moved outside the frame. If so,
  //    give that end point a random speed in the direction away from 
  //    the edge it moved off.
  // 4) Draw the line in its new location.
  ////////////////////////////////////////////////////////////////////////
  public void actionPerformed(ActionEvent arg0)
  {

    //Erase Line in its current location
    canvas.setColor(Color.WHITE);
    canvas.drawLine(x1, y1, x2, y2);
    canvas.drawLine(x3, y3, x4, y4);

    x1 += speedX1;
    y1 += speedY1;

    x2 += speedX2;
    y2 += speedY2;

    x3 += speedX3;
    y3 += speedY3;

    x4 += speedX4;
    y4 += speedY4;

    boolean hit = false;
    if (x1 < 0) 
    { speedX1 = rand.nextInt(12)+1;
      hit = true;
    }
    else if (x1 > DRAW_WIDTH) 
    {
      speedX1 = -(rand.nextInt(12)+1);
      hit = true;
    }


    if (y1 < 0) 
    { speedY1 = rand.nextInt(12)+1;
      hit = true;
    }
    else if (y1 > DRAW_HEIGHT)
    { speedY1 = -(rand.nextInt(12)+1);
      hit = true;
    }



    if (x2 < 0) 
    { speedX2 = rand.nextInt(12)+1;
      hit = true;
    }
    else if (x2 > DRAW_WIDTH) 
    {
      speedX2 = -(rand.nextInt(12)+1);
      hit = true;
    }


    if (y2 < 0) 
    { speedY2 = rand.nextInt(12)+1;
      hit = true;
    }
    else if (y2 > DRAW_HEIGHT)
    { speedY2 = -(rand.nextInt(12)+1);
      hit = true;
    }

    if (x3 < 0) 
    { speedX3 = rand.nextInt(12)+1;
      hit = true;
    }
    else if (x3 > DRAW_WIDTH) 
    {
      speedX3 = -(rand.nextInt(12)+1);
      hit = true;
    }

    if (y3 < 0) 
    { speedY3 = rand.nextInt(12)+1;
      hit = true;
    }
    else if (y3 > DRAW_WIDTH) 
    {
      speedY3 = -(rand.nextInt(12)+1);
      hit = true;
    }

    if (x4 < 0) 
    { speedX4 = rand.nextInt(12)+1;
      hit = true;
    }
    else if (x4 > DRAW_WIDTH) 
    {
      speedX4 = -(rand.nextInt(12)+1);
      hit = true;
    }

    if (y4 < 0) 
    { speedY4 = rand.nextInt(12)+1;
      hit = true;
    }
    else if (y4 > DRAW_WIDTH) 
    {
      speedY4 = -(rand.nextInt(12)+1);
      hit = true;
    }

    if (hit) boinkSound.play();

    //Draw Line in new location
    canvas.setColor(Color.RED);
    canvas.drawLine(x1, y1, x2, y2);
    canvas.drawLine(x3, y3, x4, y4);
    myPic.repaint();

  }





  /////////////////////////////////////////////////////////////////////
  // Create and run BouncingLinesWithSound
  /////////////////////////////////////////////////////////////////////
  public static void main(String[] args)
  {
    new BouncingLinesWithSound();   
  }
}

嗨我有一些代码有两条线条弹跳，当它们到达屏幕边缘时从墙壁反弹，我现在要做的就是让它们相互反弹，如果它们碰撞但是我没有线索如何开始

Answer 1

基本的“线路碰撞检测”算法将起作用。请参阅How to detect 2D line on line collision?和Line-line Intersection。您还需要使用点/行的列表而不是Xn .. Yn变量名称。