Clamp loopStart, loopEnd and offset

Fixes #363.

Author: cwilso

index.html

@@ -2009,14 +2009,18 @@ <h2 id="AudioBufferSourceNode">The AudioBufferSourceNode Interface</h2>
   An optional value in seconds where looping should begin if the
   <code>loop</code> attribute is true.  Its default <code>value</code> is 0,
   and it may usefully be set to any value between 0 and the duration of the
-  buffer.
+  buffer.  If loopStart is less than 0, looping will begin at 0.  If 
+  loopStart is greater than the duration of the buffer, looping will begin
+  at the end of the buffer.
   </dd>
   <dt>attribute double loopEnd</dt>
   <dd>
   An optional value in seconds where looping should end if the
   <code>loop</code> attribute is true.  Its default <code>value</code> is 0,
   and it may usefully be set to any value between 0 and the duration of the
-  buffer.
+  buffer.  If loopEnd is less than 0, looping will end at 0.  If 
+  loopEnd is greater than the duration of the buffer, looping will end
+  at the end of the buffer.
   </dd>
 
   <dt>
@@ -2042,7 +2046,11 @@ <h2 id="AudioBufferSourceNode">The AudioBufferSourceNode Interface</h2>
         time in the buffer (in seconds) where playback will begin. If 0 is
         passed in for this value, then playback will start from the beginning of
         the buffer.  An InvalidAccessError exception MUST be thrown if 
-        <code>offset</code> is negative or is not a finite number.
+        <code>offset</code> is negative or is not a finite number.  If 
+        <code>offset</code> is less than zero, playback will begin at the
+        beginning of the buffer.  If <code>offset</code> is greater than 
+        <code>loopEnd</code>, playback will begin at <code>loopEnd</code> 
+        (and immediately loop to <code>loopStart</code>).
       </dd>
       <dt>optional double duration</dt>
       <dd>