用Java编写游戏的键盘输入
我正在用Java编写游戏，现在它是Swing + JOGL – 一个带有GLCanvas的JFrame。
我使用keyPressed等事件处理输入（ jframe.addKeyListener(...) ），它似乎无法正常工作：
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当我同时关闭3个键时，它们没有正确注册– 显然这是键盘故障，我必须找到一个替代控制方案。 - 窗口丢失后，重新获得焦点，输入完全停止工作……
我究竟做错了什么？
有没有更好的方法来处理Java中的键盘输入？
（我宁愿切换到另一个库，比如LWJGL ……除非我别无选择）。
为了减少依赖关系，我会选择“内置”键盘处理。 如果你知道你在做什么，它的工作正常。 我将从我的游戏中粘贴一些代码：
它使用自定义重复延迟/速率处理键重复，并且没有关于组件键盘焦点所在的问题。
public class GameKeyController implements KeyEventDispatcher { private final int MAX_REPEAT_RATE = 100; // Hz private final LocalGame game; private final GamingContext context; private final Account account; Timer keyRepeatTimer; Map repeatingTasks = new EnumMap(Move.class); public GameKeyController(LocalGame game, GamingContext context, Account account) { this.game = game; this.context = context; this.account = account; } public boolean dispatchKeyEvent(KeyEvent e) { assert EventQueue.isDispatchThread(); int kc = e.getKeyCode(); if (e.getID() == KeyEvent.KEY_PRESSED) { // If repeat is activated, ignore KEY_PRESSED events. // Should actually not occur, since KEY_RELEASED *should* have been // intercepted since last KEY_PRESSED. if (kc == account.getInt(KC_MOVE_LEFT) && !isRepeating(LEFT)) move(LEFT); if (kc == account.getInt(KC_MOVE_RIGHT) && !isRepeating(RIGHT)) move(RIGHT); if (kc == account.getInt(KC_SOFT_DROP) && !isRepeating(SOFT_DROP)) move(SOFT_DROP); // Regular moves if (kc == account.getInt(KC_ROT_CW)) move(ROT_CW); if (kc == account.getInt(KC_ROT_CW2)) move(ROT_CW); if (kc == account.getInt(KC_ROT_CCW)) move(ROT_CCW); if (kc == account.getInt(KC_ROT_CCW2)) move(ROT_CCW); if (kc == account.getInt(KC_HARD_DROP)) move(HARD_DROP); if (kc == account.getInt(KC_SLIDE_DROP)) move(SLIDE_DROP); if (kc == account.getInt(KC_FULL_LEFT)) move(FULL_LEFT); if (kc == account.getInt(KC_FULL_RIGHT)) move(FULL_RIGHT); if (kc == account.getInt(KC_HOLD)) move(HOLD); if (kc == account.getInt(KC_SEND_TO_ME)) useSpecial(0); if (kc == account.getInt(KC_SEND_TO_1)) useSpecial(1); if (kc == account.getInt(KC_SEND_TO_2)) useSpecial(2); if (kc == account.getInt(KC_SEND_TO_3)) useSpecial(3); if (kc == account.getInt(KC_SEND_TO_4)) useSpecial(4); if (kc == account.getInt(KC_SEND_TO_5)) useSpecial(5); if (kc == account.getInt(KC_SEND_TO_6)) useSpecial(6); if (kc == account.getInt(KC_SEND_TO_7)) useSpecial(7); if (kc == account.getInt(KC_SEND_TO_8)) useSpecial(8); if (kc == account.getInt(KC_SEND_TO_9)) useSpecial(9); // Reported bug: Key repeat "lags on releases", that is, the key // continues to repeat a few ms after it has been released. // The following two lines gives one "upper" approximation of // when someone really wants to release the key. if (kc == account.getInt(KC_MOVE_RIGHT)) stopRepeating(LEFT); if (kc == account.getInt(KC_MOVE_LEFT)) stopRepeating(RIGHT); } if (e.getID() == KeyEvent.KEY_RELEASED) { if (kc == account.getInt(KC_MOVE_LEFT)) stopRepeating(LEFT); if (kc == account.getInt(KC_MOVE_RIGHT)) stopRepeating(RIGHT); if (kc == account.getInt(KC_SOFT_DROP)) stopRepeating(SOFT_DROP); } return false; } private synchronized void stopRepeating(Move m) { if (!isRepeating(m)) return; repeatingTasks.get(m).cancel(); repeatingTasks.remove(m); } private synchronized boolean isRepeating(Move m) { return repeatingTasks.get(m) != null; } private synchronized void move(Move move) { assert EventQueue.isDispatchThread(); context.notIdleSinceStart(); PlayfieldEvent pfe = game.move(move); // Fake wall kicks if ((move == ROT_CW || move == ROT_CCW) && account.getBool(USE_FAKE_WALL_KICKS) && !pfe.pfChanged) { // Try RIGHT and ROT, then LEFT and ROT. Playfield pf = game.getPlayfield(); if (pf.isFakeRotPossible(true, move == ROT_CW)) { game.move(RIGHT); game.move(move); } else if (pf.isFakeRotPossible(false, move == ROT_CW)) { game.move(LEFT); game.move(move); } } // Initiate key repeats int delay = account.getInt(KEY_REPEAT_DELAY); int rate = account.getInt(KEY_REPEAT_RATE); if (delay > 0 && rate > 0 && isRepeatable(move)) startRepeating(move); } private boolean isRepeatable(Move m) { return m == LEFT || m == RIGHT || m == SOFT_DROP; } private synchronized void startRepeating(Move move) { assert EventQueue.isDispatchThread(); if (isRepeating(move)) return; long delay = account.getInt(KEY_REPEAT_DELAY); int rate = account.getInt(KEY_REPEAT_RATE); Move repeatMove = move; if (rate >= MAX_REPEAT_RATE) { rate = MAX_REPEAT_RATE; repeatMove = move == LEFT ? FULL_LEFT : move == RIGHT ? FULL_RIGHT : move == SOFT_DROP ? SLIDE_DROP : null; // not a repeatable move! } long period = (long) (1000.0 / rate); if (move == SOFT_DROP) delay = period; final Move m = repeatMove; TimerTask tt = new TimerTask() { // Should only be executed by keyRepeatTimer thread. public void run() { // Remove the if-branch below and you get old school GB behavior // With the if-branch it's more TDS-ish. // TODO: Make this depend on an account-setting if (m == SOFT_DROP && game.getPlayfield().isTetOnSurface()) { stopRepeating(SOFT_DROP); return; } game.move(m); // Attempt to make it more responsive to key-releases. // Even if there are multiple this-tasks piled up (due to // "scheduleAtFixedRate") we don't want this thread to take // precedence over AWT thread. Thread.yield(); } }; repeatingTasks.put(move, tt); keyRepeatTimer.scheduleAtFixedRate(tt, delay, period); } public synchronized void init() { if (!isInited()) { keyRepeatTimer = new Timer("Key Repeat Timer"); KeyboardFocusManager.getCurrentKeyboardFocusManager().addKeyEventDispatcher(this); } } public synchronized boolean isInited() { return keyRepeatTimer != null; } public synchronized void uninit() { if (isInited()) { KeyboardFocusManager.getCurrentKeyboardFocusManager().removeKeyEventDispatcher(this); keyRepeatTimer.cancel(); keyRepeatTimer = null; } } private void useSpecial(int target) { context.notIdleSinceStart(); context.useSpecial(target); } }
本文中有关全局事件侦听器的一些提示包括使用KeyboardFocusManager捕获键事件，并可能有助于从失去焦点回来。
关于3+键，这将是棘手的，因为KeyEvent考虑了修饰符，但不考虑其API中的多个（常规）键。 您可能必须自己管理新闻状态，因为如果您获得KEY_PRESSED，则存储该键并构建当前按下的键集。 但是如果按下3个或更多按键时根本没有得到任何事件，我不确定你能做多少事情。
编辑：此外， JGame库有一个JOGL目标。 看看它如何处理关键事件可能会有所帮助。 我知道它可以同时处理至少2个键。