不规则的背景移动速度

Question

我目前正在制作侧卷轴，我一直致力于移动背景。这是我用来管理它的运动的类：

package game;

import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;

import javax.imageio.ImageIO;

import framework.GClock;

public class BackgroundManager {
public BufferedImage background;
public BufferedImage[] movingImages;
private final int y=4,x=2;
public final int scale = 3;
private float[] speed;
private Rectangle[][] rects;
private float speedScale =150f;

public BackgroundManager() {
    try {
        URL bg = BackgroundManager.class
                .getResource("/resources/background.png");
        background = ImageIO.read(bg);
        URL[] urls = new URL[4];
        urls[0] = BackgroundManager.class
                .getResource("/resources/mountainBackground.png");
        urls[1] = BackgroundManager.class
                .getResource("/resources/mountainForeground.png");
        urls[2] = BackgroundManager.class
                .getResource("/resources/treesBackground.png");
        urls[3] = BackgroundManager.class
                .getResource("/resources/treesForeground.png");

        movingImages = new BufferedImage[4];

        for (int i = 0; i < y; i++) {
            movingImages[i] = ImageIO.read(urls[i]);

        }

        int bgw = background.getWidth()*scale;

        speed = new float[4];
        for (int i = 0; i < y; i++) {
            speed[i] = speedScale * (movingImages[i].getWidth()*scale
                    / bgw-1);
            System.out.println(speed[i]);
            // maybe use
            // Image.getScaledInstance(scaledWidth,scaledHeight,Image.SCALE_DEFAULT);
        }
        rects = new Rectangle[x][y];
        for (int i = 0; i < y; i++) {
            rects[0][i] = new Rectangle(0, 0,
                    movingImages[i].getWidth()*scale,
                    movingImages[i].getHeight()*scale);
            rects[1][i] = new Rectangle(rects[0][i].width,
                    0, movingImages[i].getWidth()*scale,
                    movingImages[i].getHeight()*scale);
        }
    } catch (MalformedURLException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

public void update(GClock clock) {
    float dt = clock.getElapsedTime();

    for (int i = 0; i < y; i++) {
        if (rects[0][i].x + rects[0][i].width < -10)
            rects[0][i].x = rects[1][i].x + rects[1][i].width;
        if (rects[1][i].x + rects[1][i].width < -10)
            rects[1][i].x = rects[0][i].x + rects[0][i].width;
    }

    for (int i = 0; i < y; i++) {
        rects[0][i].x -= speed[i] * dt;
        rects[1][i].x -= speed[i] * dt;
    }
}

public void drawBackground(Graphics2D g) {
    //static background
    g.drawImage(background, 0, 0, background.getWidth() * scale,
            background.getHeight() * scale, null);
    //other layers
    for (int i = 0; i < y; i++) {
        g.drawImage(movingImages[i], rects[0][i].x, 0,
                rects[0][i].width,
                rects[0][i].height, null);
        g.drawImage(movingImages[i], rects[1][i].x, 0,
                rects[1][i].width,
                rects[1][i].height, null);

    }
/*
    // background
    g.drawImage(background, 0, 0, background.getWidth() * scale,
            background.getHeight() * scale, null);
    // mountainBackground
    g.drawImage(mountainBackground, (int) (-speed[0] * dt), 0,
            mountainBackground.getWidth() * scale,
            mountainBackground.getHeight() * scale, null);
    // mountainForeground
    g.drawImage(mountainForeground, (int) (-speed[1] * dt), 0,
            mountainForeground.getWidth() * scale,
            mountainForeground.getHeight() * scale, null);
    // treesBackground
    g.drawImage(treesBackground, (int) (-speed[2] * dt), 0,
            treesBackground.getWidth() * scale, treesBackground.getHeight()
                    * scale, null);
    // treesForeground
    g.drawImage(treesForeground, (int) (-speed[3] * dt), 0,
            treesForeground.getWidth() * scale, treesForeground.getHeight()
                    * scale, null);
*/
    }
}

GClock是我用来管理时间的课程，clock.getElapsedTime()是上次更新 - ＆gt; draw-＆gt;重绘 - ＆gt;睡眠周期所花费的时间。

出于某种原因，不是将第一张图像移动到下一张图像的右侧以模拟连续背景，而是this。在剪辑中，下一层加速直到它到达屏幕的左侧，然后匹配最后一层的速度。我已经尝试删除切换边界矩形位置的代码块，我花了大约一个小时来试图解决这个问题，但没有运气。我做错了什么？

编辑：以下是GClock的相关字段：

private long startTime;
private long dt;
private long lastTime;
private float targetTime;
private boolean isFpsCapped;

public GClock(){
    startTime=lastTime=System.currentTimeMillis();
    targetTime=1f/60f;
    isFpsCapped=true;


}   
protected void update(){
    this.dt=System.currentTimeMillis()-lastTime;    
    this.lastTime=System.currentTimeMillis();
}
public float getElapsedTime(){
    return (float)dt/1000f;

}

这是游戏循环：

while(isRunning){
        clock.update();//calculates the amount of time that the last game loop took and prepares for the next clock.update() call.
        if(!isPaused){
        this.update(clock);//update is an abstract method that is implemented into child classes. For this instance, it only contains BackgroundManager.update(clock);

        this.render(clock);//render is a method that manages the game's Graphics2D object, and calls this.draw(), which, like update(), is an abstract method called only by implementations of this class.
        this.paintScreen();//repains the screen
        }

        if(clock.isFpsCapped()){
            //thread.sleep(millis);
            try {
                Thread.sleep(clock.calculateSleepTime());//makes the thread sleep for a certain amount of time, so that the amount of time the gameloop took + calculateSleepTime() = some target time (in this case, it tries to keep the game at about 60 fps.)
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }//end of if statement
    }