From 019b6d29fe81b205d36ac34f52eb6e18ffe8f2b4 Mon Sep 17 00:00:00 2001
From: curt <curt>
Date: Fri, 31 Aug 2001 18:07:23 +0000
Subject: [PATCH] Fixed [simple] terrain following altitude hold mode to work
 again.

---
 src/Autopilot/newauto.hxx |  2 ++
 src/FDM/JSBSim.cxx        |  2 ++
 src/FDM/LaRCsim.cxx       |  2 +-
 src/Main/fg_props.cxx     | 12 ++++++++++--
 4 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/src/Autopilot/newauto.hxx b/src/Autopilot/newauto.hxx
index 87b6d7545..22af68a61 100644
--- a/src/Autopilot/newauto.hxx
+++ b/src/Autopilot/newauto.hxx
@@ -176,6 +176,8 @@ public:
     inline void set_TargetDistance( double val ) { TargetDistance = val; }
     inline double get_TargetAltitude() const { return TargetAltitude; }
     inline void set_TargetAltitude( double val ) { TargetAltitude = val; }
+    inline double get_TargetAGL() const { return TargetAGL; }
+    inline void set_TargetAGL( double val ) { TargetAGL = val; }
     inline double get_TargetClimbRate() const { return TargetClimbRate; }
     inline void set_TargetClimbRate( double val ) { TargetClimbRate = val; }
 
diff --git a/src/FDM/JSBSim.cxx b/src/FDM/JSBSim.cxx
index 4786bd662..406ce3a42 100644
--- a/src/FDM/JSBSim.cxx
+++ b/src/FDM/JSBSim.cxx
@@ -381,6 +381,8 @@ bool FGJSBsim::copy_from_JSBsim() {
                      Position->GetLongitude(),
                      Position->Geth() );
 
+    _set_Altitude_AGL( Position->GetDistanceAGL() );
+
     _set_Euler_Angles( Rotation->Getphi(),
                        Rotation->Gettht(),
                        Rotation->Getpsi() );
diff --git a/src/FDM/LaRCsim.cxx b/src/FDM/LaRCsim.cxx
index da2ee8159..be54fb096 100644
--- a/src/FDM/LaRCsim.cxx
+++ b/src/FDM/LaRCsim.cxx
@@ -469,7 +469,7 @@ bool FGLaRCsim::copy_from_LaRCsim() {
     _set_Geodetic_Position( Latitude, tmp_lon, Altitude );
     _set_Euler_Angles( Phi, Theta, Psi );
 
-    _set_Altitude_AGL( Altitude-Runway_altitude );
+    _set_Altitude_AGL( Altitude - Runway_altitude );
 
     // Miscellaneous quantities
     _set_T_Local_to_Body(T_local_to_body_m);
diff --git a/src/Main/fg_props.cxx b/src/Main/fg_props.cxx
index 396aa66e2..a2b34155a 100644
--- a/src/Main/fg_props.cxx
+++ b/src/Main/fg_props.cxx
@@ -571,6 +571,12 @@ setAPTerrainLock (bool lock)
 {
   current_autopilot->set_AltitudeMode(FGAutopilot::FG_ALTITUDE_TERRAIN);
   current_autopilot->set_AltitudeEnabled(lock);
+  current_autopilot->set_TargetAGL(
+      current_aircraft.fdm_state->get_Altitude_AGL() * SG_FEET_TO_METER
+    );
+  cout << "Target AGL = "
+       << current_aircraft.fdm_state->get_Altitude_AGL() * SG_FEET_TO_METER
+       << endl;
 }
 
 
@@ -1030,6 +1036,8 @@ fgInitProps ()
   fgSetArchivable("/autopilot/locks/glide-slope");
   fgTie("/autopilot/locks/terrain", getAPTerrainLock, setAPTerrainLock);
   fgSetArchivable("/autopilot/locks/terrain");
+  fgTie("/autopilot/settings/agl-ft", getAPAltitude, setAPAltitude);
+  fgSetArchivable("/autopilot/settings/agl-ft");
   fgTie("/autopilot/settings/climb-rate-fpm", getAPClimb, setAPClimb, false);
   fgSetArchivable("/autopilot/settings/climb-rate-fpm");
   fgTie("/autopilot/locks/heading", getAPHeadingLock, setAPHeadingLock);
@@ -1195,7 +1203,7 @@ FGAndCondition::FGAndCondition ()
 
 FGAndCondition::~FGAndCondition ()
 {
-  for (int i = 0; i < _conditions.size(); i++)
+  for (unsigned int i = 0; i < _conditions.size(); i++)
     delete _conditions[i];
 }
 
@@ -1228,7 +1236,7 @@ FGOrCondition::FGOrCondition ()
 
 FGOrCondition::~FGOrCondition ()
 {
-  for (int i = 0; i < _conditions.size(); i++)
+  for (unsigned int i = 0; i < _conditions.size(); i++)
     delete _conditions[i];
 }
 
-- 
2.39.5