java - 如何用java制作沙盒游戏

Question

我正在尝试制作一款模拟化学 react 的游戏。问题是，大约五个灰尘颗粒后，游戏崩溃了。这是移动粒子的代码:

public class Element extends Thread {
  long temperature;
  double x;
  double y;
  double XVel;
  double YVel = 5;
  ImageView iv;
  Duration dur;
  TranslateTransition tt = new TranslateTransition();

  @Override
  public void run() {
    while (true) {
      move();// calls the movement method repeatedly
      try {
        Thread.sleep(10);
      } catch (InterruptedException ex) {
        Logger.getLogger(Element.class.getName()).log(Level.SEVERE, null, ex);
      }
    }
  }

  public void initialize() {
    this.start();
  }

  /**
   * @return the temperature
   */
  public long getTemperature() {
    return temperature;
  }

  public void checkCollisions() {

  }

  public void move() {
    tt.setDuration(dur.millis(5));
    tt.setByY(YVel);
    tt.setCycleCount(1);
    tt.setNode(iv);
    tt.play();
  }
}

然后，出现此异常，游戏停止运行:

java.lang.NullPointerException
at com.sun.scenario.animation.AbstractMasterTimer.timePulseImpl(AbstractMasterTimer.java:366)
at com.sun.scenario.animation.AbstractMasterTimer.timePulseImpl(AbstractMasterTimer.java:366)
at com.sun.scenario.animation.AbstractMasterTimer$MainLoop.run(AbstractMasterTimer.java:289)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:459)
at com.sun.javafx.tk.quantum.QuantumToolkit$9.run(QuantumToolkit.java:332)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.access$100(WinApplication.java:17)
at com.sun.glass.ui.win.WinApplication$3$1.run(WinApplication.java:67)
at java.lang.Thread.run(Thread.java:744)

我不知道为什么会发生 NullPointerException，任何人都可以帮助我(我正在使用 JavaFX)吗？如果有人能告诉我这个游戏是如何做到的( http://dan-ball.jp/en/javagame/dust/ )，那将会非常有帮助，因为这个游戏展示了我正在努力实现的目标。亲自看看。

Answer 1

我发现 TranslateTransition 的内存效率并不高。当我分析我的项目时，我注意到每当放置粒子时内存峰值都不会下降。

There are numerous issues with your code as others have pointed out, study this animated physics in JavaFX sample (https://gist.github.com/james-d/8327842) to see how you could achieve the behaviour you want. – jewelsea Jun 17 at 19:30

这个引用确实很有帮助。我现在真的应该能够完成我的游戏了。