Random commit

- Added experimental adjustments to the random tetromino generator.
- Converted indentation from mixed ugliness to spaces only.

Author: hagward

README.md

@@ -12,7 +12,7 @@ tricky. I then reckoned that was a completely unnecessary optimization and
 saved myself from the headache by shoving it down the garbage chute. The score
 system is from the original Tetris but the level system is completely improvised.
 
-Feel free to [try it out](https://dl.dropboxusercontent.com/u/334931/game.html).
+Feel free to [try it out](https://dl.dropboxusercontent.com/u/334931/javascriptris/game.html).
 
 ## Contribution
 

game.html

@@ -60,6 +60,7 @@
 			p = pause<br>
 			r = restart
 		</div>
-		<script type="text/javascript" src="tetris.js"></script>
+		<script src="random.js"></script>
+		<script src="tetris.js"></script>
 	</body>
-</html>
+</html>

random.js

@@ -0,0 +1,56 @@
+/**
+ * These functions are responsible for generating "fair" "random" tetrominos.
+ * It is making sure that an 'I' tetromino comes at least every 12th round and
+ *  that a maximum of four 'S' and 'Z' tetriminos can be spawned consecutively.
+ */
+
+var g_numTetros = [];
+var g_prevQueue = [];
+
+resetRandomSystem();
+
+/**
+ * Resets the queue and tetromino count array.
+ */
+function resetRandomSystem() {
+    g_numTetros = [0, 0, 0, 0, 0, 0, 0];
+    g_prevQueue.splice(0, g_prevQueue.length);
+}
+
+/**
+ * Returns a new "random" tetromino and updates the queue.
+ */
+function getRandomTetromino() {
+    var newTetromino;
+    var len = g_prevQueue.length;
+
+    if (g_numTetros[0] == 0 && len == 12) {
+        // Make sure that we at least get one I each 12th time.
+        newTetromino = 0;
+    } else if (len >= 4
+        && g_prevQueue[len-1] == g_prevQueue[len-2]
+        && g_prevQueue[len-2] == g_prevQueue[len-3]
+        && g_prevQueue[len-3] == g_prevQueue[len-4]
+        && g_prevQueue[len-4] >= 5) {
+        // If the four last tetriminos were 'S' or 'Z', spawn something else.
+        newTetromino = Math.floor(Math.random() * 5);
+    } else {
+        newTetromino = Math.floor(Math.random() * 7);
+    }
+    pushTetromino(newTetromino);
+    return newTetromino;
+}
+
+/**
+ * Pushes a tetromino into the queue and updates g_numTetros to hold the
+ * correct number of instances of the tetromino in the queue.
+ */
+function pushTetromino(tetromino) {
+    g_numTetros[tetromino]++;
+    // If the array is larger than 12, we remove the oldest element.
+    if (g_prevQueue.length == 12) {
+        g_numTetros[g_prevQueue[0]]--;
+        g_prevQueue.shift();
+    }
+    g_prevQueue.push(tetromino);
+}