當球速增加時槳會通過槳

Question

我正在嘗試創建一個乒乓球遊戲，到目前爲止，除了球之外，我還有一切爲我工作。起初，我把球的x和y軸每次向上移動一個空格。它工作正常，直到我決定將它增加到2.我無法弄清楚我的代碼有什麼問題，我需要幫助。

import java.awt.Graphics; 
import java.awt.event.KeyEvent; 
import java.awt.event.KeyListener; 
import javax.swing.JFrame; 
import javax.swing.JPanel; 

public class Pong extends JPanel implements KeyListener{ 

int x = 90; 
int y = 90; 
int rectytop = 30; 
int rectytop2 = 30; 
int rectybottom = rectytop + 100; 
int rectybottom2 = rectytop2 + 100; 

int border = 30; 
boolean balldown = true; 
boolean ballright = true; 
boolean playerborderup = false; 
boolean playerborderdown = false; 
boolean balltouch1 = false; 
boolean balltouch2 = false; 


private void moveball() { 

    if (balldown == true){ 
     y = y + 2; 
    } 

    if (y == getHeight()-border){ 
     balldown = false; 
    } 
    if (balldown == false){ 
     y = y - 2; 
    } 






    if (ballright == true){ 
     x = x + 2; 
    } 
    if (x == getWidth()-border){ 
     ballright = false; 
    } 
    if (ballright == false){ 
     x = x - 2; 
    } 



    if (y == 0){ 
     balldown = true; 
    } 

    if (x == 0){ 
     ballright = true; 
    } 



    if (balltouch1 == false){ 
     if (x == 75){ 
      if(y < rectybottom && y > rectytop){ 
       ballright = true; 
      } 
     } 
    } 


    if (balltouch2 == false){ 
     if (x == 390 && y < rectybottom2 && y > rectytop2){ 
       ballright = false; 
     } 
    } 


}  

@Override 
public void paint(Graphics g){ 
    super.paint(g); 

    //drawing ball and paddles 
    g.fillOval(x, y, 30, 30); 
    g.fillRect(45 , rectytop, 30, 100); 
    g.fillRect(425, rectytop2, 30, 100); 

} 


public static void main(String[] args) throws InterruptedException { 

    //making the window 
    JFrame f = new JFrame("Pong Game"); 
    Pong game = new Pong(); 
    f.setVisible(true); 
    f.setSize(500, 500);//1024, 724 
    f.setResizable(true); 
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
    f.addKeyListener(game); 

    //game code 

    f.add(game);   
    while (true){ 
     game.repaint(); 
     game.moveball(); 

     Thread.sleep(10); 


    } 
} 

@Override 
public void keyTyped(KeyEvent e) { 

} 

@Override 
public void keyPressed(KeyEvent e) { 

    //player one 
    if (e.getKeyCode() == KeyEvent.VK_W){ 
     if (rectytop == 0){ 
      playerborderup = true; 
     } 
     if (rectytop != 0){ 
      playerborderup = false; 
     } 
     if (playerborderup == true){ 
      rectytop = rectytop + 0; 
      rectybottom = rectytop + 100; 
      repaint(); 
     } 
     if (playerborderup == false){ 
      rectytop = rectytop - 5; 
      rectybottom = rectytop + 100; 
      repaint(); 
     } 

    } 

    if (e.getKeyCode() == KeyEvent.VK_S){ 
     if (rectytop == 585){ 
      playerborderdown = true; 
     } 
     if (rectytop != 585){ 
      playerborderdown = false; 
     } 
     if (playerborderdown == true){ 
      rectytop = rectytop - 0; 
      rectybottom = rectytop + 100; 
      repaint(); 
     } 
     if (playerborderdown == false){ 
      rectytop = rectytop + 5; 
      rectybottom = rectytop + 100; 
      repaint(); 
     } 
    } 


    //player two 
    if (e.getKeyCode() == KeyEvent.VK_UP){ 
     if (rectytop2 == 0){ 
      playerborderup = true; 
     } 
     if (rectytop2 != 0){ 
      playerborderup = false; 
     } 
     if (playerborderup == true){ 
      rectytop2 = rectytop2 + 0; 
      rectybottom2 = rectytop2 + 100; 
      repaint(); 
     } 
     if (playerborderup == false){ 
      rectytop2 = rectytop2 - 5; 
      rectybottom2 = rectytop2 + 100; 
      repaint(); 
     } 

    } 

    if (e.getKeyCode() == KeyEvent.VK_DOWN){ 
     if (rectytop2 == 585){ 
      playerborderdown = true; 
     } 
     if (rectytop2 != 585){ 
      playerborderdown = false; 
     } 
     if (playerborderdown == true){ 
      rectytop2 = rectytop2 - 0; 
      rectybottom2 = rectytop2 + 100; 
      repaint(); 
     } 
     if (playerborderdown == false){ 
      rectytop2 = rectytop2 + 5; 
      rectybottom2 = rectytop2 + 100; 
      repaint(); 
     } 
    } 







} 

@Override 
public void keyReleased(KeyEvent e) { 
    } 





} 

Answer 1

您正在使用if (x == 75)來檢測與左側槳葉的碰撞。但是如果速度是2，那麼球的速度是2，但是總是平穩的，永遠不會等於75.爲了快速解決問題，請對照範圍檢查x：if (x > 60 && x < 75)

Answer 2

由於每次移動2次，它可能會跳過某些座標。因此，當你說

if (y == getHeight()-border){ 
    balldown = false; 
} 

Ÿ可以從走的getHeight（） - 邊界+ 1的getHeight（） - 邊界 - 1，永不滿足這個條件。因此，將其更改爲一個範圍或一個小於。你的新代碼應該是

if (y <= getHeight()-border +1){ 
    balldown = false;  //change the +1 and -1 to have difference at least speed number 
} 

請注意，您必須爲具有==其他IFS做同樣的，改變

if (x == getWidth()-border){ 
    ballright = false; 
} 

if (y == 0){ 
    balldown = true; 
} 

if (x == 0){ 
    ballright = true; 
} 

到

if (x <= getWidth()-border +1){ 
    ballright = false; 
} 

if (y <= 1){ 
    balldown = true; 
} 

if (x <= 1){ 
    ballright = true; 
} 

注意，您可以解決問題還通過說明位置是否離開邊界正好一個，暫時將位置減1而不是2.