libs-gui/Tools/gsnd/portaudio/docs/pa_drivermodel.c.txt

/*
	This file contains the host-neutral code for implementing multiple driver model 
	support in PortAudio.

	It has not been compiled, but it is supplied only for example purposes at this stage.

	TODO: use of CHECK_DRIVER_MODEL is bogus in some instances since some 
		of those functions don't return a PaError


*/

#include "pa_drivermodel.h.txt"


#ifndef PA_MULTIDRIVER 
/* single driver support, most functions will stay in the implementation files */

PaDriverModelID Pa_CountDriverModels()
{
	return 1;
}

/*
Perhaps all drivers should define this with this signature
const PaDriverModelInfo* Pa_GetDriverModelInfo( PaDriverModelID driverModelID )
{
}
*/

PaDeviceID Pa_DriverModelDefaultInputDeviceID( PaDriverModelID driverModelID )
{
	return Pa_GetDefaultInputDeviceID();
}


PaDeviceID Pa_DriverModelDefaultOutputDeviceID( PaDriverModelID driverModelID )
{
	return Pa_GetDefaultInputDeviceID();
}

/*
Perhaps all drivers should define with this signature
int Pa_DriverModelMinNumBuffers( PaDriverModelID driverModelID, int framesPerBuffer, double sampleRate )
{

}
*/

int Pa_DriverModelCountDevices( PaDriverModelID driverModelID )
{
	return Pa_CountDevices();
}

PaDeviceID Pa_DriverModelGetDeviceID(PaDriverModelID driverModelID, int perDriverModelIndex )
{
	return perDriverModelIndex;
}


#else
/* multidriver support */


typedef PaError (*PaInitializeFunPtr)( PaDriverModelImplementation** );

/*
	the initializers array is a static table of function pointers
	to all the available driverModels on the current platform.

	the order of pointers in the array is important. the first
	pointer is always considered to be the "default" driver model.
*/

static PaInitializeFunPtr driverModelInitializers[] = {
#ifdef WINDOWS
	PaWin32WMME_MultiDriverInitialize,
	PaWin32DS_MultiDriverInitialize,
	PaASIO_MultiDriverInitialize
#endif
#ifdef MAC
	PaMacSM_MultiDriverInitialize,
	PaMacCA_MultiDriverInitialize,
	PaASIO_MultiDriverInitialize
#endif
/* other platforms here */
	(PaInitializeFunPtr*)0 /* NULL terminate the list */
}; 


/*
	the driverModels array is a dynamically created table of
	currently available driverModels.
*/
static PaDriverModelImplementation* driverModels = 0;
static int numDriverModels = 0;


#define PA_CHECK_INITIALIZED\
	if( driverModels == 0 )
		return paLibraryNotInitialised

#define PA_CHECK_DRIVER_MODEL_ID( id )
	if( id < 0 || id >= numDriverModels )
		return paBadDriverModelID;


/*
	ConvertPublicDeviceIdToImplementationDeviceId converts deviceId
	from a public device id, to a device id for a particular 
	PortAudio implementation. On return impl will either point
	to a valid implementation or will be NULL.
*/
static void ConvertPublicDeviceIDToImplementationDeviceID( 
	PaDriverModelImplementation *impl, PaDeviceID deviceID )
{
	int i, count;

	impl = NULL;

	for( i=0; i < numDriverModels; ++i ){
		count = driverModels[i]->countDevices();
		if( deviceID < count ){
			impl = driverModels[i];
			return NULL;			
		}else{
			deviceID -= count;
		}
	}
}

static PaDeviceID ConvertImplementationDeviceIDToPublicDeviceID( 
		PaDriverModelID driverModelID, PaDeviceID deviceID )
{
	int i;

	for( i=0; i < driverModelID; ++i )
		deviceID += driverModels[i]->countDevices();
}


PaError Pa_Initialize( void )
{
	PaError result = paNoError;
	int i, initializerCount;
	PaDriverModelImplementation *impl;

	if( driverModels != 0 )
		return paAlreadyInitialized;

	/* count the number of driverModels */
	initializerCount=0;
	while( driverModelInitializers[initializerCount] != 0 ){
		++initializerCount;
	}

	driverModels = malloc( sizeof(PaDriverModelImplementation*) * initializerCount );
	if( driverModels == NULL )
		return paInsufficientMemory;

	numDriverModels = 0;
	for( i=0; i<initializerCount; ++i ){
		result = (*driverModelInitializers[i])( &impl );
		if( result == paNoError ){
			driverModels[numDriverModels] = impl;
			++numDriverModels;
		}else{
			// TODO: terminate the drivers which have already been initialized.
		}
	}

	return result;
}



PaError Pa_Terminate( void )
{
	int i;

	PA_CHECK_INITIALIZED;

	/*
		rather than require each implementation to do it separately we could
		keep track of all open streams and close them here
	*/

	for( i=0; i<numDriverModels; ++i )
		driverModels[i]->terminate( driverModels[i] );
}


long Pa_GetHostError( void )
{
	PA_CHECK_INITIALIZED;
	
	under construction. depends on error text proposal.
}


const char *Pa_GetErrorText( PaError errnum )
{
	PA_CHECK_INITIALIZED;

	under construction. may need to call driver model specific code 
	depending on how the error text proposal pans out.
}



int Pa_CountDevices()
{
	int i, result;

	PA_CHECK_INITIALIZED;

	result = 0;
	for( i=0; i < numDriverModels; ++i )
		result += driverModels[i]->countDevices();
	
	return result;
}


PaDeviceID Pa_GetDefaultInputDeviceID( void )
{
	PA_CHECK_INITIALIZED;

	return driverModels[0]->getDefaultInputDeviceID();
}

PaDeviceID Pa_GetDefaultOutputDeviceID( void )
{
	PA_CHECK_INITIALIZED;

	return driverModels[0]->getDefaultInputDeviceID();
}


const PaDeviceInfo* Pa_GetDeviceInfo( PaDeviceID deviceID )
{
	PaDriverModelImplementation *impl;	

	PA_CHECK_INITIALIZED;

	ConvertPublicDeviceIDToImplementationDeviceID( impl, deviceID );
	if( impl == NULL )
		return paInvalidDeviceID;

	return impl->getDeviceInfo( deviceID );
}

/* NEW MULTIPLE DRIVER MODEL FUNCTIONS ---------------------------------- */

PaDriverModelID Pa_CountDriverModels()
{
	PA_CHECK_INITIALIZED;

	return numDriverModels;
}


const PaDriverModelInfo* Pa_GetDriverModelInfo( PaDriverModelID driverModelID )
{
	PA_CHECK_INITIALIZED;
	PA_CHECK_DRIVER_MODEL_ID( driverModelID );

	return driverModels[ driverModelID ]->getDriverModelInfo();
}


PaDeviceID Pa_DriverModelDefaultInputDeviceID( PaDriverModelID driverModelID )
{
	PA_CHECK_INITIALIZED;
	PA_CHECK_DRIVER_MODEL_ID( driverModelID );

	return ConvertImplementationDeviceIDToPublicDeviceID( driverModelID,
			driverModels[ driverModelID ]->getDefaultInputDeviceID();
}


PaDeviceID Pa_DriverModelDefaultOutputDeviceID( PaDriverModelID driverModelID )
{
	PA_CHECK_INITIALIZED;
	PA_CHECK_DRIVER_MODEL_ID( driverModelID );
	
	return ConvertImplementationDeviceIDToPublicDeviceID( driverModelID,
			driverModels[ driverModelID ]->getDefaultOutputDeviceID();
}


int Pa_DriverModelMinNumBuffers( PaDriverModelID driverModelID, int framesPerBuffer, double sampleRate )
{
	PA_CHECK_INITIALIZED;
	PA_CHECK_DRIVER_MODEL_ID( driverModelID );

	return driverModels[ driverModelID ]->getMinNumBuffers( int framesPerBuffer, double sampleRate );
}


int Pa_DriverModelCountDevices( PaDriverModelID driverModelID )
{
	PA_CHECK_INITIALIZED;
	PA_CHECK_DRIVER_MODEL_ID( driverModelID );

	return driverModels[ driverModelID ]->coundDevices();
}

PaDeviceID Pa_DriverModelGetDeviceID(PaDriverModelID driverModelID, int perDriverModelIndex )
{
	PA_CHECK_INITIALIZED;
	PA_CHECK_DRIVER_MODEL_ID( driverModelID );

	return ConvertImplementationDeviceIDToPublicDeviceID( driverModelID, perDriverModelIndex );
}

/* END NEW MULTIPLE DRIVER MODEL FUNCTIONS ------------------------------ */


PaError Pa_OpenStream( PortAudioStream** stream,
				PaDeviceID inputDevice,
				int numInputChannels,
				PaSampleFormat inputSampleFormat,
				void *inputDriverInfo,
				PaDeviceID outputDevice,
				int numOutputChannels,
				PaSampleFormat outputSampleFormat,
				void *outputDriverInfo,
				double sampleRate,
				unsigned long framesPerBuffer,
				unsigned long numberOfBuffers,
				PaStreamFlags streamFlags,
				PortAudioCallback *callback,
				void *userData )
{
	PaError result;
	PaDriverModelImplementation *inputImpl, *outputImpl, impl;

	PA_CHECK_INITIALIZED;
	
	if( inputDevice != paNoDevice ){
		ConvertPublicDeviceIDToImplementationDeviceID( inputImpl, inputDevice );
		if( inputImpl == NULL )
			return paInvalidDeviceID;
		else
			impl = inputImpl;	
	}

	if( outputDevice != paNoDevice ){
		ConvertPublicDeviceIDToImplementationDeviceID( outputImpl, outputDevice );
		if( outputImpl == NULL )
			return paInvalidDeviceID;
		else
			impl = outputImpl;
	}

	if( inputDevice != paNoDevice && outputDevice != paNoDevice ){	
		if( inputImpl != outputImpl )
			return paDevicesMustBelongToTheSameDriverModel;
	}

	
	result = impl->openStream( stream, inputDevice, numInputChannels, inputSampleFormat, inputDriverInfo,
				outputDevice, numOutputChannels, outputSampleFormat, outputDriverInfo,
				sampleRate, framesPerBuffer, numberOfBuffers, streamFlags, callback, userData );


	if( result == paNoError )
		((PaStreamImplementation*)stream)->magic = PA_STREAM_MAGIC;
	
	return result;
}


PaError Pa_OpenDefaultStream( PortAudioStream** stream,
				int numInputChannels,
				int numOutputChannels,
				PaSampleFormat sampleFormat,
				double sampleRate,
				unsigned long framesPerBuffer,
				unsigned long numberOfBuffers,
				PortAudioCallback *callback,
				void *userData )
{
	PaError result;
	int inputDevice = driverModels[0]->getDefaultInputDeviceID;
	int outputDevice = driverModels[0]->getDefaultOutputDeviceID;		
		
	result = driverModels[0]->openStream( stream, inputDevice, numInputChannels, sampleFormat, 0, 
								outputDevice, numOutputChannels, sampleFormat, 0, 
								sampleRate, framesPerBuffer, numberOfBuffers,
								streamFlags, callback, userData );

	if( result == paNoError )
		((PaStreamImplementation*)stream)->magic = PA_STREAM_MAGIC;
	
	return result;
}


PaError Pa_CloseStream( PortAudioStream* stream )
{
	PA_CHECK_INITIALIZED;

	PaError result = ((PaStreamImplementation*)stream)->close();

	if( result == PaNoError )
		((PaStreamImplementation*)stream)->magic = 0; /* clear magic number */

	return result;
}


PaError Pa_StartStream( PortAudioStream *stream );
{
	PA_CHECK_INITIALIZED;

	return ((PaStreamImplementation*)stream)->start();
}


PaError Pa_StopStream( PortAudioStream *stream );
{
	PA_CHECK_INITIALIZED;

	return ((PaStreamImplementation*)stream)->stop();
}


PaError Pa_AbortStream( PortAudioStream *stream );
{
	PA_CHECK_INITIALIZED;

	return ((PaStreamImplementation*)stream)->abort();
}


PaError Pa_StreamActive( PortAudioStream *stream )
{
	PA_CHECK_INITIALIZED;

	return ((PaStreamImplementation*)stream)->active();
}

PaTimestamp Pa_StreamTime( PortAudioStream *stream )
{
	PA_CHECK_INITIALIZED;

	return ((PaStreamImplementation*)stream)->time();
}


double Pa_StreamCPULoad( PortAudioStream* stream )
{
	PA_CHECK_INITIALIZED;

	return ((PaStreamImplementation*)stream)->cpuLoad();
}



int Pa_GetMinNumBuffers( PaDeviceID deviceID, int framesPerBuffer, double sampleRate )
{	
	PaDriverModelImplementation *impl;
	PA_CHECK_INITIALIZED;

	ConvertPublicDeviceIDToImplementationDeviceID( impl, deviceID );
	if( impl == NULL )
		return paInvalidDeviceID;

	return impl->getMinNumBuffers( framesPerBuffer, sampleRate );	
}


void Pa_Sleep( long msec )
{
	same as existing implementaion
}


PaError Pa_GetSampleSize( PaSampleFormat format )
{
	same as existing implementation
}

#endif /* PA_MULTIDRIVER */