球碰撞问题，只有一半的球碰撞

Question

我不明白为什么在我接过球的前半部分时，当我控制的球击中移动球的右半部时，它不会激活冲突代码来杀死程序。

我把它设置为测量你控制的球和经过的球之间的距离。我仍然感到困惑，为什么我可以在没有计划关闭的情况下落地进行下半场的比赛。

---

import java.awt.BorderLayout; 
import java.awt.Color; 
import java.awt.Dimension; 
import java.awt.EventQueue; 
import java.awt.Graphics; 
import java.awt.Graphics2D; 
import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 
import java.awt.event.KeyEvent; 
import java.awt.image.BufferedImage; 

import javax.swing.AbstractAction; 
import javax.swing.ActionMap; 
import javax.swing.InputMap; 
import javax.swing.JFrame; 
import javax.swing.JPanel; 
import javax.swing.KeyStroke; 
import javax.swing.Timer; 
import javax.swing.UIManager; 
import javax.swing.UnsupportedLookAndFeelException; 
import java.awt.event.ActionListener; 
import java.awt.event.KeyListener; 
import javax.swing.ImageIcon; 

public class JumpingSprite extends JPanel implements KeyListener { 

//public int yPos; 

public static void main(String[] args) { 
    new JumpingSprite(); 
} 




public JumpingSprite() { 


    EventQueue.invokeLater(new Runnable() { 
     @Override 
     public void run() { 



      try { 
          UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); 
      } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) { 
      } 

      JFrame frame = new JFrame("Mr.Baird"); 
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
      frame.setLayout(new BorderLayout()); 
      TestPane testPane = new TestPane(); 
      frame.add(testPane); 
      frame.pack(); 
      frame.setLocationRelativeTo(null); 
      frame.setVisible(true); 







     } 
    }); 
} 

public class TestPane extends JPanel { 

    int getyPos(){ 

     return yPos; 

    } 

    protected static final int SPRITE_HEIGHT = 60; 
    protected static final int SPRITE_WIDTH = 60; 
    private float vDelta; 
    private float rbDelta; 
    private float rbDegDelta; 
    public int yPos; 
    private float gDelta; // Gravity 
    private Timer engine; 
    private boolean bounce = false; 

    int ballx = 1000; 
    int bally = 500; 
    int ballw = 100; 
    int ballh = 100; 

    int ball2x = 1500; 
    int ball2y = 480; 
    int ball2w = 120; 
    int ball2h = 120; 

    int ball3x = 2500; 
    int ball3y = 0; 
    int ball3w = 600; 
    int ball3h = 600; 
    public TestPane() { 

     yPos = getPreferredSize().height - SPRITE_HEIGHT; 
     vDelta = 0; 
     gDelta = 3f; 
     rbDegDelta = 30f; //affects how many bounces mang 

     InputMap im = getInputMap(WHEN_IN_FOCUSED_WINDOW); 
     ActionMap am = getActionMap(); 
     im.put(KeyStroke.getKeyStroke(KeyEvent.VK_SPACE, 0), "jump"); 
     am.put("jump", new AbstractAction() { 
      @Override 
      public void actionPerformed(ActionEvent e) { 


       if (yPos + SPRITE_HEIGHT == getHeight()) { 
        vDelta = -40  ; 
        rbDelta = vDelta; 
        bounce = true; 
       } 
      } 
     }); 

     engine = new Timer(15, new ActionListener() { 
      @Override 
      public void actionPerformed(ActionEvent e) { 
       int height = getHeight(); 


       if (height > 0) { 

        if (bounce) { 

         yPos += vDelta; 

         vDelta += gDelta; 
         // If the sprite is not on the ground 
         if (yPos + SPRITE_HEIGHT >= height) { 
          // put on le ground 
          yPos = height - SPRITE_HEIGHT; 

          if (rbDelta >= 0) { 
           // Stop bouncin 
           bounce = false; 
          } else { 
           // Add the re-bound degregation delta to the re-bound delta 
           rbDelta += rbDegDelta; 
           // Set the vDelta... 
           vDelta = rbDelta; 
          } 
         } 
        } 
       } 
    if (Math.sqrt((Math.pow((500 - (ballx)), 2)) +     Math.pow((yPos - bally), 2)) <= (50)) { 
        System.exit(0); 
       } 
       if (Math.sqrt((Math.pow((500 - (ball2x)), 2)) + Math.pow((yPos - ball2y), 2)) <= (60)) { 
        System.exit(0); 
       } 
       if (Math.sqrt((Math.pow((500 - (ball3x)), 2)) + Math.pow((yPos - ball3y), 2)) <= (350)) { 
        System.exit(0); 
       } 


       ballx = ballx-8; 
       ball2x = ball2x-8; 
       ball3x = ball3x-8; 
       repaint(); 


      } 
     }); 
     engine.start(); 
    } 

    @Override 
    public Dimension getPreferredSize() { 
     return new Dimension(1000, 600); 
    } 

    @Override 
    protected void paintComponent(Graphics g) { 
     //addin all them pretty colors to le object 
     super.paintComponent(g); 
     //Graphics2D g2d = (Graphics2D) g.create(); 
     g.setColor(Color.black); 
     g.fillRect(0,0,1000,1000); 
     int width = getWidth() - 1; 
     int xPos = (width - SPRITE_WIDTH)/2; 
     g.setColor(Color.blue); 
     g.fillOval(xPos, yPos, SPRITE_WIDTH, SPRITE_HEIGHT); 
     //g.dispose(); 


     g.setColor(Color.red); 
     g.fillOval(ballx, bally, ballw, ballh); 

     g.setColor(Color.green); 
     g.fillOval(ball2x, ball2y, ball2w, ball2h); 

     g.setColor(Color.pink); 
     g.fillOval(ball3x, ball3y, ball3w, ball3h); 
    } 





} 

@Override 
public void keyPressed(KeyEvent arg0) { 
    // TODO Auto-generated method stub 

} 

@Override 
public void keyReleased(KeyEvent arg0) { 
    // TODO Auto-generated method stub 

} 

@Override 
public void keyTyped(KeyEvent arg0) { 
    // TODO Auto-generated method stub 

} 

}

Answer 1

的一般的解决这个问题是计算两个球/圆的中心之间的（欧几里得）距离，并且确定该长度小于其综合半径。另一种方法是从Shape s创建java.awt.Area s，并使用Area.intersect(Area)！= null;