1 files changed, 53 insertions, 0 deletions
diff --git a/docs/examples/spacewar/Timer.java b/docs/examples/spacewar/Timer.java
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+/*
+
+Copyright (c) Xerox Corporation 1998-2002.  All rights reserved.
+
+Use and copying of this software and preparation of derivative works based
+upon this software are permitted.  Any distribution of this software or
+derivative works must comply with all applicable United States export control
+laws.
+
+This software is made available AS IS, and Xerox Corporation makes no warranty
+about the software, its performance or its conformity to any specification.
+
+|<---            this code is formatted to fit into 80 columns             --->|
+|<---            this code is formatted to fit into 80 columns             --->|
+|<---            this code is formatted to fit into 80 columns             --->|
+
+
+Timer.java
+Part of the Spacewar system.
+
+*/
+
+package spacewar;
+
+
+class Timer extends Thread {
+
+    private final static int TICK_PERIOD = 40;  // time between ticks in millis
+
+    private Game game;
+
+    Game getGame() { return game; }
+
+    Timer (Game theGame) {
+        super("Timer");
+        game = theGame;
+    }
+
+    public void run() {
+        long t1, tdiff;
+        while (true) {
+            t1 = System.currentTimeMillis();
+            getGame().clockTick();
+            tdiff = System.currentTimeMillis() - t1;
+            if (tdiff < TICK_PERIOD) {
+                try {
+                    sleep (Math.max(0 , TICK_PERIOD - tdiff));
+                }
+                catch (InterruptedException e) { }
+            }
+        }
+    }
+}