当许多精灵在屏幕上时,Java Swing游戏的性能很差

Question

我正在Swing中制作一个简单的塔防游戏,当我尝试在屏幕上放置许多精灵(超过20个)时,我遇到了性能问题.

整个游戏发生在具有setIgnoreRepaint(true)的JPanel上.这是paintComponent方法(con是Controller):

public void paintComponent(Graphics g){
    super.paintComponent(g);
    //Draw grid
    g.drawImage(background, 0, 0, null);
    if (con != null){
        //Draw towers
        for (Tower t : con.getTowerList()){
            t.paintTower(g);
        }
        //Draw targets
        if (con.getTargets().size() != 0){
            for (Target t : con.getTargets()){
                t.paintTarget(g);
            }
            //Draw shots
            for (Shot s : con.getShots()){
                s.paintShot(g);
            }
        }
    }
}

Target类simple在其当前位置绘制BufferedImage.getImage方法不会创建新的BufferedImage,它只返回Controller类的实例:

public void paintTarget(Graphics g){
    g.drawImage(con.getImage("target"), getPosition().x - 20, getPosition().y - 20, null);
}

每个目标都运行一个Swing Timer来计算它的位置.这是它调用的ActionListener:

public void actionPerformed(ActionEvent e) {
    if (!waypointReached()){
        x += dx;
        y += dy;
        con.repaintArea((int)x - 25, (int)y - 25, 50, 50);
    }
    else{
        moving = false;
        mover.stop();
    }
}

private boolean waypointReached(){
    return Math.abs(x - currentWaypoint.x) <= speed && Math.abs(y - currentWaypoint.y) <= speed;
}

除此之外,只在放置新塔时调用repaint().

如何提高性能？

Answer 1

每个目标都运行一个Swing Timer来计算它的位置.这是它调用的ActionListener:

这可能是你的问题 - 让每个目标/子弹(我假设？)负责跟踪何时更新自己并绘制自己听起来像是相当多的工作.更常见的方法是沿着线路循环

while (gameIsRunning) {
  int timeElapsed = timeSinceLastUpdate();
  for (GameEntity e : entities) {
    e.update(timeElapsed);
  }
  render(); // or simply repaint in your case, I guess
  Thread.sleep(???); // You don't want to do this on the main Swing (EDT) thread though
}

从本质上讲,链上的一个对象有责任跟踪游戏中的所有实体,告诉他们自己更新并渲染它们.