[Flightgear-devel] RE: [Flightgear-flightmodel] Alpha goofiness

[Norman V. <nh...@ca...>]

John Wojnaroski writes:
>
>While I'm here, has anyone looked at the HUD heading? 
>Departing on runway 28 at SFO, the aircraft
>heading should be between 275 and 284 (runways are numbered to 
>the nearest 10 degrees of
>the actual alignment to mag north). The panel appears corect, 
>but all the HUDs show 297.
>Am I missing something and  the only one that is seeing this problem?

The HUD compass is a gyro compass  < GPS LIKE >
these based on TRUE NORTH

The following changes will allow for setting this in the xml file

add to cockpit.cxx
float get_heading_mag ( void )
{
  return current_aircraft.fdm_state->get_Psi() * SGD_RADIANS_TO_DEGREES -
    globals->get_mag()->get_magvar() * SGD_RADIANS_TO_DEGREES;
}

add to hud.hxx
extern float get_heading_mag ( void );

add to hud.cxx
static instr_item * 
readCard(const SGPropertyNode * node)
{
....
	if(loadfn=="heading_mag")
		load_fn = get_heading_mag;
	else
....
}


then in FG_ROOT / Huds / Instruments / Default / hudcard.xml
change the Gyrocompass <loadfn> from 
'heading' to 'heading_mag'

I'll get a patch into Curt when he gets back on line

Cheers

Norman