滚动背景，JAVA

Question

我需要让我的游戏背景移到了所有的时间..

我知道我需要使用一些线程添加变量“Y”图像坐标

我试图做一些事情，但是当它开始将所有的后台得到某种原因裸奔，不能理解为什么...

图片：streaking background

public class Background { 
private BufferedImage image; 
..... 
.... 

public Background(int x, int y) { 
    this.x = x; 
    this.y = y; 

    // Try to open the image file background.png 
    try { 
     BufferedImageLoader loader = new BufferedImageLoader(); 
     image = loader.loadImage("/backSpace.png"); 

    } 
    catch (Exception e) { System.out.println(e); } 

} 

/** 
* Method that draws the image onto the Graphics object passed 
* @param window 
*/ 
public void draw(Graphics window) { 

    // Draw the image onto the Graphics reference 
    window.drawImage(image, getX(), getY(), image.getWidth(), image.getHeight(), null); 

    // Move the x position left for next time 
    this.y +=1 ; 
} 


public class ScrollingBackground extends Canvas implements Runnable { 

// Two copies of the background image to scroll 
private Background backOne; 
private Background backTwo; 

private BufferedImage back; 

public ScrollingBackground() { 
    backOne = new Background(); 
    backTwo = new Background(backOne.getImageWidth(), 0); 

    new Thread(this).start(); 
    setVisible(true); 
} 

@Override 
public void run() { 
    try { 
     while (true) { 
      Thread.currentThread().sleep(5); 
      repaint(); 
     } 
    } 
    catch (Exception e) {} 
} 

@Override 
public void update(Graphics window) { 
    paint(window); 
} 

public void paint(Graphics window) { 
    Graphics2D twoD = (Graphics2D)window; 

    if (back == null) 
     back = (BufferedImage)(createImage(getWidth(), getHeight())); 

    Graphics buffer = back.createGraphics(); 

    backOne.draw(buffer); 
    backTwo.draw(buffer); 

    twoD.drawImage(back, null, 0, 0); 

} 

Answer 1

你d ont需要一个新的线程，这只是在这种情况下过分复杂。 您只需要继续向背景的Y坐标添加一个因子。 例如：

float scrollFactor = 0.5f; //Moves the background 0.5 pixels up per call of the draw method 

public void draw(Graphics window) { 

    window.drawImage(image, getX(), getY(), image.getWidth(), image.getHeight(), null); 

    this.y += scrollFactor; 
}