【发布时间】：2021-09-21 06:38:53
【问题描述】：
我决定尝试制作游戏并且我喜欢 Java，所以我开始学习 here 的教程。我确实偏离了视频几次，因为我觉得它更干净，同时与教程的代码同义，但我认为不会以任何方式影响代码的工作方式。例如，对我来说，渲染器和对象注册表应该只有一个实例是有意义的，所以我将它们设为单例。
到目前为止，我的代码应该是创建一个黑色背景的窗口，窗口中间有一个蓝色方块代表播放器，这样就可以了。但是，它也应该响应于wasd键而四处滑动，并且无论如何都会更慢地向一个方向漂移。相反，它什么也不做。
我花了不少于一个小时试图弄清楚为什么它不起作用。它似乎滴答作响，数据看起来正在正确更新，但即使我的渲染方法也被调用，屏幕并没有改变。
这是我到目前为止的所有代码，因为我对这个问题一无所知。对于列出整个项目，我深表歉意。
public class Game implements Runnable {
private final Thread thread;
private boolean running = false;
Game() {
thread = new Thread(this);
}
public static void main(String[] args) {
Game game = new Game();
game.start();
new Player(600,450,0));
}
private void start() {
thread.start();
running = true;
}
@Override
public void run() {
double tps = 10.0;
double nsPerTick = 1000000000 / tps;
double delta = 0;
int frames = 0;
long timer = System.currentTimeMillis();
long lTime = System.nanoTime();
long now;
while (running) {
now = System.nanoTime();
delta += (now - lTime) / nsPerTick;
lTime = now;
while (delta >= 1) {
Registry.getInstance().tick();
delta--;
}
if (running) Renderer.getInstance().run();
frames++;
if (System.currentTimeMillis() - timer > 1000) {
timer += 1000;
System.out.println("FPS: " + frames);
frames = 0;
}
}
stop();
}
private void stop() {
try {
thread.join();
} catch (Exception e) {
e.printStackTrace();
}
running = false;
}
}
public class Renderer extends Canvas {
private static final Renderer renderer = new Renderer();
private final Window window;
private final BufferStrategy bs;
private final Graphics g;
boolean black = true;
private Renderer() {
window = new Window(1200, 900, "First Game", this);
this.createBufferStrategy(2);
bs = this.getBufferStrategy();
g = bs.getDrawGraphics();
addKeyListener(Controller.getInstance());
}
public static Renderer getInstance() {return renderer;}
public void run() {
g.setColor(Color.BLACK);
//this was to see if even the background would update, it wouldn't
//g.setColor(black ? Color.BLACK : Color.WHITE);
//black = !black;
g.fillRect(0,0,1200, 900);
Registry.getInstance().render();
g.dispose();
bs.show();
}
public Graphics getGraphics() {return g;}
private static class Window extends Canvas {
private Window(int width, int height, String title, Renderer renderer) {
JFrame frame = new JFrame(title);
frame.setPreferredSize(new Dimension(width, height));
frame.setMinimumSize(new Dimension(width, height));
frame.setMaximumSize(new Dimension(width, height));
frame.setResizable(false);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
frame.add(renderer);
frame.setVisible(true);
}
}
}
public class Registry {
private static final Registry reg = new Registry();
private final LinkedList<GameObject> objects = new LinkedList<>();
private Registry() {
}
public static Registry getInstance() { return reg; }
public void tick() { //System.out.println("tick");
objects.forEach(GameObject::tick); }
public void render() { objects.forEach(GameObject::render); }
public void add(GameObject gameObject) { objects.add(gameObject); }
public void remove(GameObject gameObject) { objects.remove(gameObject);}
}
public class Controller extends KeyAdapter {
private static final Controller controller = new Controller();
private final HashMap<Character,Boolean> keyStates = new HashMap<>();
private Controller() {
}
public static Controller getInstance() {
return controller;
}
public void keyPressed(KeyEvent e) {
if (!keyStates.getOrDefault(e.getKeyChar(), true)) System.out.println(e.getKeyChar() + " down");
keyStates.put(e.getKeyChar(),true);
}
public void keyReleased(KeyEvent e) {
keyStates.put(e.getKeyChar(),false);
System.out.println(e.getKeyChar() + " up " + keyStates.size());
}
public boolean isKeyDown(char c) {return keyStates.getOrDefault(c,false);}
}
public abstract class GameObject {
protected Graphics graphics = Renderer.getInstance().getGraphics();
protected final ObjectType type;
protected float x,y,r;
protected GameObject(ObjectType objectType, float x, float y, float r) {
this.type = objectType;
this.x = x;
this.y = y;
this.r = r;
Registry.getInstance().add(this);
}
public abstract void tick();
public abstract void render();
public void destroy() { Registry.getInstance().remove(this); }
public float getX() { return x; }
public void setX(float x) { this.x = x; }
public float getY() { return y; }
public void setY(float y) { this.y = y; }
public float getR() { return r; }
public void setR(float r) { this.r = r; }
}
public class Player extends GameObject {
private final Controller controller;
public Player(float x, float y, float r) {
super(ObjectType.PLAYER, x, y, r);
controller = Controller.getInstance();
}
@Override
public void tick() {
this.x += 1;
if (controller.isKeyDown('w')) x += 2;
if (controller.isKeyDown('a')) y -= 2;
if (controller.isKeyDown('s')) x -= 2;
if (controller.isKeyDown('d')) y += 2;
}
@Override
public void render() {
graphics.setColor(Color.BLUE);
graphics.fillRect((int) (this.x-12),(int) (this.y-12), 24,24);
}
}
【问题讨论】：
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Oracle 有一个有用的教程，Creating a GUI With JFC/Swing，它将帮助您开发一个合适的 Swing GUI。跳过 Netbeans 部分。随机的视频教程可能会导致您遇到各种问题，而且正如您所发现的，几乎没有人可以帮助您。