Add GameLoop class

src/GameLoop.java

+/*** In The Name of Allah ***/
+
+/**
+ * A very simple structure for the main game loop.
+ * THIS IS NOT PERFECT, but works for most situations.
+ * Note that to make this work, none of the 2 methods 
+ * in the while loop (update() and render()) should be 
+ * long running! Both must execute very quickly, without 
+ * any waiting and blocking!
+ * 
+ * Detailed discussion on different game loop design
+ * patterns is available in the following link:
+ *    http://gameprogrammingpatterns.com/game-loop.html
+ * 
+ * @author Seyed Mohammad Ghaffarian
+ */
+public class GameLoop implements Runnable {
+	
+	/**
+	 * Frame Per Second.
+	 * Higher is better, but any value above 24 is fine.
+	 */
+	public static final int FPS = 30;
+	
+	private GameFrame canvas;
+	private GameState state;
+
+	public GameLoop(GameFrame frame) {
+		canvas = frame;
+	}
+	
+	/**
+	 * This must be called before the game loop starts.
+	 */
+	public void init() {
+		state = new GameState();
+		canvas.addKeyListener(state.getKeyListener());
+		canvas.addMouseListener(state.getMouseListener());
+		canvas.addMouseMotionListener(state.getMouseMotionListener());
+	}
+
+	@Override
+	public void run() {
+		boolean gameOver = false;
+		while (!gameOver) {
+			try {
+				long start = System.currentTimeMillis();
+				//
+				state.update();
+				canvas.render(state);
+				gameOver = state.gameOver;
+				//
+				long delay = (1000 / FPS) - (System.currentTimeMillis() - start);
+				if (delay > 0)
+					Thread.sleep(delay);
+			} catch (InterruptedException ex) {
+			}
+		}
+		canvas.render(state);
+	}
+}