Minor RageSound improvements

Nothing major here - updating C style casts, moving repeated function calls into variables, changing lrint's...

**RageSound.cpp**

- Initialize m_pSource to nullptr in the member initializer list, rather than in the body of the constructor
- Define an undefined variable `iSourceFrame`
- Change a `lrint` to a `static_cast<int>+0.5`
- Implement missing error handling in `SetStopModeFromString` with a log message

**RageSoundManager**

- Combined the iterator increment and the erase operation for `Update` into one line to prevent needing to create the `next` variable, since GameLoop calls this method frequently

**RageSoundReader**

- This method is called from RageSound just after making sure iFrames isn't equal to 0, so it's not needed for RageSoundReader to do it again.
- We will never fail to read a file 100 times. If we do, it's because of I/O errors, so make that more clear.

src/RageSound.cpp

@@ -66,12 +66,11 @@ RageSound::~RageSound()
 
 RageSound::RageSound( const RageSound &cpy ):
 	RageSoundBase( cpy ),
-	m_Mutex( "RageSound" )
+	m_Mutex( "RageSound" ),
+	m_pSource( nullptr )
 {
 	ASSERT(SOUNDMAN != nullptr);
 
-	m_pSource = nullptr;
-
 	*this = cpy;
 }
 
@@ -283,7 +282,7 @@ int RageSound::GetDataToPlay( float *pBuffer, int iFrames, std::int64_t &iStream
 	while( iFrames > 0 )
 	{
 		float fRate = 1.0f;
-		int iSourceFrame;
+		int iSourceFrame = 0;
 
 		/* Read data from our source. */
 		int iGotFrames = m_pSource->RetriedRead( pBuffer + (iFramesStored * m_pSource->GetNumChannels()), iFrames, &iSourceFrame, &fRate );
@@ -291,6 +290,7 @@ int RageSound::GetDataToPlay( float *pBuffer, int iFrames, std::int64_t &iStream
 		if( iGotFrames == RageSoundReader::ERROR )
 		{
 			m_sError = m_pSource->GetError();
+			// This error probably indicates an I/O error, rather than a decoding error.
 			LOG->Warn( "Decoding %s failed: %s", GetLoadedFilePath().c_str(), m_sError.c_str() );
 		}
 
@@ -331,7 +331,7 @@ void RageSound::StartPlaying()
 	ASSERT( !m_bPlaying );
 
 	// Move to the start position.
-	SetPositionFrames( std::lrint(m_Param.m_StartSecond * samplerate()) );
+	SetPositionFrames( static_cast<int>((m_Param.m_StartSecond * samplerate())) + 0.5 );
 
 	/* If m_StartTime is in the past, then we probably set a start time but took too
 	 * long loading.  We don't want that; log it, since it can be unobvious. */
@@ -510,8 +510,9 @@ float RageSound::GetPositionSeconds( bool *bApproximate, RageTimer *pTimestamp )
 		*bApproximate = false;
 
 	/* If we're not playing, just report the static position. */
+	float sampleRate = static_cast<float>(samplerate());
 	if( !IsPlaying() )
-		return m_iStoppedSourceFrame / float(samplerate());
+		return m_iStoppedSourceFrame / sampleRate;
 
 	/* 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. */
@@ -520,11 +521,11 @@ float RageSound::GetPositionSeconds( bool *bApproximate, RageTimer *pTimestamp )
 		// LOG->Trace( "no data yet; %i", m_iStoppedSourceFrame );
 		if( bApproximate )
 			*bApproximate = true;
-		return m_iStoppedSourceFrame / float(samplerate());
+		return m_iStoppedSourceFrame / sampleRate;
 	}
 
 	int iSourceFrame = GetSourceFrameFromHardwareFrame( iCurrentHardwareFrame, bApproximate );
-	return iSourceFrame / float(samplerate());
+	return iSourceFrame / sampleRate;
 }
 
 
@@ -539,16 +540,17 @@ bool RageSound::SetPositionFrames( int iFrames )
 	}
 
 	int iRet = m_pSource->SetPosition( iFrames );
+	RString filePath = GetLoadedFilePath();
 	if( iRet == -1 )
 	{
 		m_sError = m_pSource->GetError();
-		LOG->Warn( "SetPositionFrames: seek %s failed: %s", GetLoadedFilePath().c_str(), m_sError.c_str() );
+		LOG->Warn( "SetPositionFrames: seek %s failed: %s", filePath.c_str(), m_sError.c_str() );
 	}
 	else if( iRet == 0 )
 	{
 		/* Seeked past EOF. */
 		LOG->Warn( "SetPositionFrames: %i samples is beyond EOF in %s",
-			iFrames, GetLoadedFilePath().c_str() );
+			iFrames, filePath.c_str() );
 	}
 	else
 	{
@@ -642,7 +644,7 @@ void RageSound::SetStopModeFromString( const RString &sStopMode )
 	}
 	else
 	{
-		// error
+		LOG->Warn("Invalid stop mode \"%s\" for sound \"%s\"", sStopMode.c_str(), m_sFilePath.c_str());
 	}
 }
 

src/RageSoundManager.cpp

@@ -112,20 +112,18 @@ void RageSoundManager::Update()
 	/* Scan m_mapPreloadedSounds for sounds that are no longer loaded, and delete them. */
 	g_SoundManMutex.Lock(); /* lock for access to m_mapPreloadedSounds, owned_sounds */
 	{
-		std::map<RString, RageSoundReader_Preload*>::iterator it, next;
-		it = m_mapPreloadedSounds.begin();
-
-		while( it != m_mapPreloadedSounds.end() )
+		for( auto it = m_mapPreloadedSounds.begin(); it != m_mapPreloadedSounds.end(); )
 		{
-			next = it; ++next;
 			if( it->second->GetReferenceCount() == 1 )
 			{
 				LOG->Trace( "Deleted old sound \"%s\"", it->first.c_str() );
 				delete it->second;
-				m_mapPreloadedSounds.erase( it );
+				it = m_mapPreloadedSounds.erase(it);
+			}
+			else
+			{
+				++it;
 			}
-
-			it = next;
 		}
 	}
 

src/RageSoundReader.cpp

@@ -8,13 +8,10 @@ REGISTER_CLASS_TRAITS( RageSoundReader, pCopy->Copy() );
 /* Read(), handling the STREAM_LOOPED and empty return cases. */
 int RageSoundReader::RetriedRead( float *pBuffer, int iFrames, int *iSourceFrame, float *fRate )
 {
-	if( iFrames == 0 )
-		return 0;
-
 	/* pReader may return 0, which means "try again immediately".  As a failsafe,
 	 * only try this a finite number of times.  Use a high number, because in
 	 * principle each filter in the stack may cause this. */
-	int iTries = 100;
+	int iTries = 10;
 	while( --iTries )
 	{
 		if( fRate )
@@ -29,9 +26,12 @@ int RageSoundReader::RetriedRead( float *pBuffer, int iFrames, int *iSourceFrame
 
 		if( iGotFrames != 0 )
 			return iGotFrames;
+
+		// If the user is having I/O issues, give them a hint in the logs.
+		LOG->Warn( "Read() failed, retrying..." );
 	}
 
-	LOG->Warn( "Read() busy looping" );
+	LOG->Warn( "Read() returned a failure status after 10 attempts to read the file; likely an I/O error" );
 
 	/* Pretend we got EOF. */
 	return RageSoundReader::END_OF_FILE;