update comment

stepmania/src/RageSound.cpp

@@ -628,7 +628,7 @@ int64_t RageSound::GetPositionSecondsInternal( bool *bApproximate ) const
 	if( !IsPlaying() )
 		return m_iStoppedSourceFrame;
 
-	/* If we don't yet have any position data, GetPCM hasn't yet been called at all,
+	/* If we don't yet have any position data, CommitPlayingPosition hasn't yet been called at all,
 	 * so guess what we think the real time is. */
 	if( m_HardwareToStreamMap.IsEmpty() || m_StreamToSourceMap.IsEmpty() )
 	{

stepmania/src/RageSoundPosMap.cpp

@@ -168,8 +168,8 @@ int64_t pos_map_queue::Search( int64_t iSourceFrame, bool *bApproximate ) const
 	 * Return the closest position.
 	 *
 	 * There are three cases when this happens: 
-	 * 1. After the first GetPCM call, but before it actually gets heard.
-	 * 2. After GetPCM returns EOF and the sound has flushed, but before
+	 * 1. Before the first CommitPlayingPosition call.
+	 * 2. After GetDataToPlay returns EOF and the sound has flushed, but before
 	 *    SoundStopped has been called.
 	 * 3. Underflow; we'll be given a larger frame number than we know about.
 	 */

stepmania/src/arch/Sound/RageSoundDriver.h

@@ -34,9 +34,9 @@ public:
 	 * RageSound::CommitPlayingPosition. */
 	virtual int64_t GetPosition() const = 0;
 
-	/* When a sound is finished playing (GetPCM returns less than requested) and
-	 * the sound has been completely flushed (so GetPosition is no longer meaningful),
-	 * call RageSoundBase::SoundIsFinishedPlaying(). */
+	/* When a sound is finished playing (GetDataToPlay returns 0) and the sound has
+	 * been completely flushed (so GetPosition is no longer meaningful), call
+	 * RageSoundBase::SoundIsFinishedPlaying(). */
 
 	/* Optional, if needed:  */
 	virtual void Update() { }