//Called periodically
bool AudioStream::update()
{
	XAUDIO2_VOICE_STATE state;
	voice->GetState(&state);
	if(!almostDone)
	{
		if(state.BuffersQueued < BUFFER_COUNT - 1)
			fillBuffer();
	}
	else if(state.BuffersQueued == 0)
		finished = true;
	return !finished;
}
void AudioStream::fillBuffer()
{
	HRESULT hr;
	size_t readBytes;
	if(!readBlock(currentDiskReadBuffer, &readBytes))
		almostDone = true;
	assert(readBytes > 0);
	//submit buffer
	XAUDIO2_BUFFER buffer = {0};
	buffer.pAudioData = buffers[currentDiskReadBuffer];
	buffer.AudioBytes = readBytes;
	if(almostDone)
		buffer.Flags |= XAUDIO2_END_OF_STREAM;
	if(FAILED(hr = voice->SubmitSourceBuffer(&buffer)))
		throw exception::DxError(hr);
	//cycle buffers
	(++currentDiskReadBuffer) %= BUFFER_COUNT;
}
void AudioStream::initStream()
{
	HRESULT hr;
	//create the source voice
	if(FAILED(hr = audio->getXAudio()->CreateSourceVoice(&voice, &format)))
		throw exception::DxError(hr);
	voice->SetVolume(audio->getMusicVolume(),audio->getOpSet());
	//fill all the buffers
	for(unsigned i=0;iStart(0,audio->getOpSet());
	//add to audio object for updating/managing
	audio->addStream(this);
}

VorbisAudioStream::VorbisAudioStream(Audio *audio, const std::string &fileName)
:AudioStream(audio,"File: " + fileName)
{
	file = fopen(fileName.c_str(), "rb");
	if(!file)throw exception::FileOpenError(fileName);
	ov_open_callbacks(file,&vorbisFile,0,0,OV_CALLBACKS_DEFAULT);
	info = ov_info(&vorbisFile, -1);
	
	memset(&format, 0, sizeof(format));
	format.cbSize          = sizeof(format);
	format.nChannels       = info->channels;
	format.wBitsPerSample  = 16;//ogg/vorbis is always 16bit
	format.nSamplesPerSec  = info->rate;
	format.nAvgBytesPerSec = format.nSamplesPerSec * format.nChannels * 2;
	format.nBlockAlign     = format.nChannels * 2;
	format.wFormatTag      = 1;
	
	initStream();
}
bool VorbisAudioStream::readBlock(int bufferId, size_t *readBytes)
{
	*readBytes = 0;
	int sec = 0;
	int ret = 1;
	memset(&buffers[bufferId], 0, BUFFER_SIZE);
	//Read in the bits
	while(ret > 0 && (*readBytes)<BUFFER_SIZE)
	{
		ret = ov_read(&vorbisFile, (char*)buffers[bufferId]+(*readBytes),
			BUFFER_SIZE-(*readBytes), 0, 2, 1, &sec);
		*readBytes += ret;
	}
	return ret > 0;
}