fakegpsreceiver.cpp

SYMBIAN GPS NMEA协议实现

/************************************************************************/
/* Bluteooth Test           The.Berlin.Factor                 Juni 2003 */
/************************************************************************/

#include <E32Math.h>

#include "gps/impl/FakeGpsReceiver.h"



#define PI 3.14145

static const TInt KDefaultInitialDelay = 1000;		/*milli-seconds*/
static const TInt KDefaultPeriodicInterval = 1000;	/*milli-seconds*/

static const TReal KDefaultLatitude = 13.4699217;
static const TReal KDefaultLongitude = 52.5064617;

static const TReal KDefaultRadius = 0.0125;
static const TReal KDefaultSimulationSpeed = 0.025;



CFakeGpsReceiver * CFakeGpsReceiver::NewL( ) {

	CFakeGpsReceiver * self = NewLC( );
	CleanupStack::Pop( );

	return( self );

}



CFakeGpsReceiver * CFakeGpsReceiver::NewLC( ) {

	CFakeGpsReceiver * self = new ( ELeave ) CFakeGpsReceiver( );
	CleanupStack::PushL( self );
	self->ConstructL( );

	return( self );

}



CFakeGpsReceiver::CFakeGpsReceiver( ) {

}



CFakeGpsReceiver::~CFakeGpsReceiver( ) {

	delete( iHeartBeat ); iHeartBeat = NULL;

}



void CFakeGpsReceiver::ConstructL( ) {

	SetDefaults( );

	TTimeIntervalMicroSeconds32 delay( KDefaultInitialDelay * 1000 );
	TTimeIntervalMicroSeconds32 interval( KDefaultPeriodicInterval * 1000 );
	TCallBack callBack( HeartBeat, this );

	iHeartBeat = CPeriodic::New( CActive::EPriorityStandard );
	iHeartBeat->Start( delay, interval, callBack );

	iLastPos.SetTimeInfo( 0, 2425 );

}



void CFakeGpsReceiver::SetDefaults( ) {

	iCenterPos.Set( KDefaultLatitude, KDefaultLongitude );

	iRadius = KDefaultRadius;
	iSimulationSpeed = KDefaultSimulationSpeed;

}



void CFakeGpsReceiver::AdvanceSimulation( ) {

	TReal sin, cos;
	Math::Sin( sin, iSimulationPosition );
	Math::Cos( cos, iSimulationPosition );

	TReal xPos = iCenterPos.Longitude( ) + sin * iRadius;
	TReal yPos = iCenterPos.Latitude( ) + cos * iRadius;

	TReal utcTime = iLastPos.UtcTime( ) + 1;
	if ( utcTime > ( 60 * 60 * 24 ) )
		utcTime = 0;

	TReal heading = iSimulationPosition * 360 / 2 * PI + 90;
	if ( heading > 360 ) heading -= 360;

	iLastPos.Set( xPos, yPos );
	iLastPos.SetExtendedInfo( ETrue, 8, 1.1 );
	iLastPos.SetTimeInfo( utcTime, iLastPos.TickCount( ) + 12 );
	iLastPos.SetCourseData( heading, 19.5, ETrue );

	// TODO: Idealerweise geht man hier nicht synchron ab, sondern legt die
	// neue Position in eine Queue und verarbeitet diese asynchron. Damit
	// der CallBack nicht zu lange braucht.. wegen CPeriodic Timer..
	SendUpdate( iLastPos );

	iSimulationPosition += iSimulationSpeed;
	while ( iSimulationPosition >= 2 * PI )
		iSimulationPosition -= 2 * PI;

}



TInt CFakeGpsReceiver::HeartBeat( TAny * aPtr ) {

	CFakeGpsReceiver * gpsReceiver = STATIC_CAST( CFakeGpsReceiver *, aPtr );

	gpsReceiver->AdvanceSimulation( );

	return( 0 );

}