snd_wave_mixer.cpp

hl2 source code. Do not use it illegal.

}

void CAudioMixerWave::SetDirection( bool forward )
{
	m_bForward = forward;
}

bool CAudioMixerWave::GetDirection( void ) const
{
	return m_bForward;
}

void CAudioMixerWave::SetAutoDelete( bool autodelete )
{
	m_bAutoDelete = autodelete;
}

bool CAudioMixerWave::GetAutoDelete( void ) const
{
	return m_bAutoDelete;
}

//-----------------------------------------------------------------------------
// Purpose: 
// Input  : *pChannel - 
//			sampleCount - 
//			outputRate - 
//-----------------------------------------------------------------------------
void CAudioMixerWave::IncrementSamples( channel_t *pChannel, int startSample, int sampleCount,int outputRate, bool forward /*= true*/ )
{
	int inputSampleRate = (int)(pChannel->pitch * m_pData->Source().SampleRate());
	float rate = (float)inputSampleRate / outputRate;

	int startpos = startSample;

	if ( !forward )
	{
		int requestedstart = startSample - (int)( sampleCount * rate );
		if ( requestedstart < 0 )
			return;

		startpos = max( 0, requestedstart );
		SetSamplePosition( startpos );
	}

	while ( sampleCount > 0 )
	{
		int inputSampleCount;
		int outputSampleCount = sampleCount;
		
		if ( outputRate != inputSampleRate )
		{
			inputSampleCount = (int)(sampleCount * rate);
		}
		else
		{
			inputSampleCount = sampleCount;
		}
		
		sampleCount -= outputSampleCount;
		if ( forward )
		{
			m_sample += inputSampleCount;
			m_absoluteSample += inputSampleCount;
		}
	}
}

//-----------------------------------------------------------------------------
// Purpose: The device calls this to request data.  The mixer must provide the
//			full amount of samples or have silence in its output stream.
// Input  : *pDevice - requesting device
//			sampleCount - number of samples at the output rate
//			outputRate - sampling rate of the request
// Output : Returns true to keep mixing, false to delete this mixer
//-----------------------------------------------------------------------------
bool CAudioMixerWave::SkipSamples( channel_t *pChannel, int startSample, int sampleCount, int outputRate, bool forward /*= true*/ )
{
	int offset = 0;

	int inputSampleRate = (int)(pChannel->pitch * m_pData->Source().SampleRate());
	float rate = (float)inputSampleRate / outputRate;
	fixedint fracstep = FIX_FLOAT( rate );

	sampleCount = min( sampleCount, PAINTBUFFER_SIZE );

	int startpos = startSample;

	if ( !forward )
	{
		int requestedstart = startSample - (int)( sampleCount * rate );
		if ( requestedstart < 0 )
			return false;

		startpos = max( 0, requestedstart );
		SetSamplePosition( startpos );
	}

	while ( sampleCount > 0 )
	{
		int availableSamples;
		int inputSampleCount;
		char *pData = NULL;
		int outputSampleCount = sampleCount;
		
		if ( outputRate != inputSampleRate )
		{
			inputSampleCount = (int)(sampleCount * rate);
			if ( !forward )
			{
				startSample = max( 0, startSample - inputSampleCount );
			}
			int availableSamples = GetOutputData( (void **)&pData, startSample, inputSampleCount, forward );
			if ( !availableSamples )
				break;

			if ( availableSamples < inputSampleCount )
			{
				outputSampleCount = (int)(availableSamples / rate);
				inputSampleCount = availableSamples;
			}

			// compute new fraction part of sample index
			float offset = (m_fracOffset / FIX_SCALE) + (rate * outputSampleCount);
			offset = offset - (float)((int)offset);
			m_fracOffset = FIX_FLOAT(offset);
		}
		else
		{
			if ( !forward )
			{
				startSample = max( 0, startSample - sampleCount );
			}
			availableSamples = GetOutputData( (void **)&pData, startSample, sampleCount, forward );
			if ( !availableSamples )
				break;
			outputSampleCount = availableSamples;
			inputSampleCount = availableSamples;

		}
		offset += outputSampleCount;
		sampleCount -= outputSampleCount;
		if ( forward )
		{
			m_sample += inputSampleCount;
			m_absoluteSample += inputSampleCount;
		}

		if ( m_loop != 0 && m_sample >= m_loop )
		{
			SetSamplePosition( m_startpos );
		}

	}

	if ( sampleCount > 0 )
		return false;

	return true;
}

//-----------------------------------------------------------------------------
// Purpose: The device calls this to request data.  The mixer must provide the
//			full amount of samples or have silence in its output stream.
// Input  : *pDevice - requesting device
//			sampleCount - number of samples at the output rate
//			outputRate - sampling rate of the request
// Output : Returns true to keep mixing, false to delete this mixer
//-----------------------------------------------------------------------------
bool CAudioMixerWave::MixDataToDevice( IAudioDevice *pDevice, channel_t *pChannel, int startSample, int sampleCount, int outputRate, bool forward /*= true*/ )
{
	int offset = 0;

	int inputSampleRate = (int)(pChannel->pitch * m_pData->Source().SampleRate());
	float rate = (float)inputSampleRate / outputRate;
	fixedint fracstep = FIX_FLOAT( rate );

	sampleCount = min( sampleCount, PAINTBUFFER_SIZE );

	int startpos = startSample;

	if ( !forward )
	{
		int requestedstart = startSample - (int)( sampleCount * rate );
		if ( requestedstart < 0 )
			return false;

		startpos = max( 0, requestedstart );
		SetSamplePosition( startpos );
	}

	while ( sampleCount > 0 )
	{
		int availableSamples;
		int inputSampleCount;
		char *pData = NULL;
		int outputSampleCount = sampleCount;
		
		
		if ( outputRate != inputSampleRate )
		{
			inputSampleCount = (int)(sampleCount * rate);

			int availableSamples = GetOutputData( (void **)&pData, startpos, inputSampleCount, forward );
			if ( !availableSamples )
				break;

			if ( availableSamples < inputSampleCount )
			{
				outputSampleCount = (int)(availableSamples / rate);
				inputSampleCount = availableSamples;
			}

			Mix( pDevice, pChannel, pData, offset, m_fracOffset, fracstep, outputSampleCount, 0, forward );
			
			// compute new fraction part of sample index
			float offset = (m_fracOffset / FIX_SCALE) + (rate * outputSampleCount);
			offset = offset - (float)((int)offset);
			m_fracOffset = FIX_FLOAT(offset);
		}
		else
		{
			availableSamples = GetOutputData( (void **)&pData, startpos, sampleCount, forward );
			if ( !availableSamples )
				break;

			outputSampleCount = availableSamples;
			inputSampleCount = availableSamples;

			Mix( pDevice, pChannel, pData, offset, m_fracOffset, FIX(1), outputSampleCount, 0, forward );
		}
		offset += outputSampleCount;
		sampleCount -= outputSampleCount;

		if ( forward )
		{
			m_sample += inputSampleCount;
			m_absoluteSample += inputSampleCount;
		}

		if ( m_loop != 0 && m_sample >= m_loop )
		{
			SetSamplePosition( m_startpos );
		}

	}

	if ( sampleCount > 0 )
		return false;

	return true;
}