Copied code from java implementation of Throttle.reinit(). After testing, I found this method was leaving older values in the middle of younger values

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@5497 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/as/com/threerings/util/ArrayUtil.as

@@ -228,6 +228,14 @@ public class ArrayUtil
         return true;
     }
 
+    public static function copy (
+        src :Array, srcoffset :uint, dst :Array, dstoffset :uint, count :uint) :void
+    {
+        for (var ii :uint = 0; ii < count; ++ii) {
+            dst[dstoffset++] = src[srcoffset++];
+        }
+    }
+
     /**
      * Implementation of remove methods.
      */

src/as/com/threerings/util/Throttle.as

@@ -77,14 +77,21 @@ public class Throttle
     public function reinit (operations :int, period :int) :void
     {
         var ops :Array = ArrayUtil.create(operations, 0);
-        // copy as much as we can of our most recent operations into our new array
-        var copyCount :int = Math.min(operations, _ops.length);
-        var srcOffset :int = _oldestOp + _ops.length*2 - 1; // need *2 to prevent copying _ops[-1]
-        var destOffset :int = operations-1;
-        for (var ii :int = 0; ii < copyCount; ii++) {
-            ops[destOffset-ii] = _ops[(srcOffset-ii) % _ops.length];
+        var ii :int;
+        var oldestOp :int;
+        if (operations > _ops.length) {
+            // copy to a larger buffer, leaving zeroes at the beginning
+            oldestOp = _oldestOp + operations - _ops.length;
+            ArrayUtil.copy(_ops, 0, ops, 0, _oldestOp);
+
+        } else if (operations < _ops.length) {
+            // copy to a smaller buffer, truncating older operations
+            oldestOp = (_oldestOp + _ops.length - operations) % _ops.length;
+            var endCount :int = Math.min(_ops.length - oldestOp, operations);
+            ArrayUtil.copy(_ops, oldestOp, ops, 0, endCount);
+            ArrayUtil.copy(_ops, 0, ops, endCount, operations - endCount);
+            _oldestOp = 0;
         }
-        _oldestOp = Math.max(0, operations-_ops.length);
         _ops = ops;
         _period = period;
     }
@@ -171,7 +178,7 @@ public class Throttle
         var now :int = getTimer();
         var ages :Array = []
         for (var ii :int = 0; ii < _ops.length; ++ii) {
-            ages.push(now - _ops[(_oldestOp + ii) % _ops.length]);
+            ages.push(now - _ops[ii]);
         }
         return "[" + StringUtil.toString(ages) + "] [Oldest idx = " + _oldestOp + "]";
     }