On Thu, 2008-10-23 at 09:44 +0200, James Turner wrote:
> On 23 Oct 2008, at 02:19, Csaba Halász wrote:
>
> >
> > Of course it isn't valid, inside the function it is only setting a
> > local variable (pass by value), and it does not return anything.
> > As the _runway argument is output only, there is no reason to pass it
> > as argument. Rather, the function should have a return type of
> > FGRunway*.
>
> Grrr - kicking myself for not seeing this, this is all because
> FGRunway was on the stack previously, and the Mk-VIII didn't use a
> reference for the out parameter. Returning a pointer is of course
> cleaner, I even thought about doing that re-factoring, without
> spotting that the our parameter was broken.
>
> Thanks for figuring this out.
>
> James
>
Thanks to Csaba for helping out with the C++. This works a treat. I
attach the complete patch for fixing the MK_VIII problems. Could some
check and commit please?
Kind regards,
Alasdair
Index: mk_viii.hxx
===================================================================
RCS file: /var/cvs/FlightGear-0.9/source/src/Instrumentation/mk_viii.hxx,v
retrieving revision 1.7
diff -u -r1.7 mk_viii.hxx
--- mk_viii.hxx 15 Aug 2008 18:48:12 -0000 1.7
+++ mk_viii.hxx 23 Oct 2008 14:06:13 -0000
@@ -1563,7 +1563,7 @@
double to_heading);
double get_azimuth_difference (const FGRunway *_runway);
- void select_runway (const FGAirport *airport, FGRunway *_runway);
+ FGRunway* select_runway (const FGAirport *airport);
void update_runway ();
void get_bias_area_edges (Position *edge,
Index: mk_viii.cxx
===================================================================
RCS file: /var/cvs/FlightGear-0.9/source/src/Instrumentation/mk_viii.cxx,v
retrieving revision 1.10
diff -u -r1.10 mk_viii.cxx
--- mk_viii.cxx 11 Sep 2008 08:38:10 -0000 1.10
+++ mk_viii.cxx 23 Oct 2008 14:06:16 -0000
@@ -4489,10 +4489,10 @@
// This selection algorithm is not specified in [SPEC], but
// http://www.egpws.com/general_information/description/runway_select.htm
// talks about automatic runway selection.
-void
-MK_VIII::TCFHandler::select_runway (const FGAirport *airport,
- FGRunway *_runway)
+FGRunway*
+MK_VIII::TCFHandler::select_runway (const FGAirport *airport)
{
+ FGRunway* _runway = 0;
double min_diff = 360;
for (unsigned int r=0; r<airport->numRunways(); ++r) {
@@ -4504,6 +4504,7 @@
_runway = rwy;
}
} // of airport runways iteration
+ return _runway;
}
bool MK_VIII::TCFHandler::AirportFilter::pass(FGAirport *a)
@@ -4532,15 +4533,14 @@
// the airport's reference point.
AirportFilter filter(mk);
const FGAirport *airport = globals->get_airports()->search(
- mk_data(gps_latitude).get(), mk_data(gps_longitude).get(),
+ mk_data(gps_longitude).get(), mk_data(gps_latitude).get(),
0.5, filter);
if (!airport) return;
has_runway = true;
- FGRunway* _runway;
- select_runway(airport, _runway);
+ FGRunway* _runway = select_runway(airport);
runway.center.latitude = _runway->latitude();
runway.center.longitude = _runway->longitude();
-------------------------------------------------------------------------
This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
Build the coolest Linux based applications with Moblin SDK & win great prizes
Grand prize is a trip for two to an Open Source event anywhere in the world
http://moblin-contest.org/redirect.php?banner_id=100&url=/
_______________________________________________
Flightgear-devel mailing list
Flightgear-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/flightgear-devel
