From a1137ed940710c6531fa12e5427fcaa6d1f3f0bd Mon Sep 17 00:00:00 2001
From: Thorsten Brehm <brehm@patagonia.southamerica>
Date: Tue, 5 Oct 2010 22:34:23 +0200
Subject: [PATCH] Another GPWS fix: terrain clearance filter must be reset on
 reset/reposition. Queue of recent altitude samples must be cleared on
 reset/reposition to avoid nuisance alerts...

---
 src/Instrumentation/mk_viii.cxx | 8 ++++++++
 src/Instrumentation/mk_viii.hxx | 3 ++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/Instrumentation/mk_viii.cxx b/src/Instrumentation/mk_viii.cxx
index 25e0f2491..d69cc96ad 100755
--- a/src/Instrumentation/mk_viii.cxx
+++ b/src/Instrumentation/mk_viii.cxx
@@ -362,6 +362,7 @@ MK_VIII::SystemHandler::update ()
       if (replay_state != last_replay_state)
 	{
 	  mk->alert_handler.reposition();
+	  mk->io_handler.reposition();
 
 	  last_replay_state = replay_state;
 	  state = STATE_REPOSITION;
@@ -1065,6 +1066,7 @@ MK_VIII::IOHandler::boot ()
   mk_doutput(glideslope_cancel) = power_saved.glideslope_cancel;
 
   altitude_samples.clear();
+  reset_terrain_clearance();
 }
 
 void
@@ -1364,6 +1366,12 @@ MK_VIII::IOHandler::reset_terrain_clearance ()
   update_terrain_clearance();
 }
 
+void
+MK_VIII::IOHandler::reposition ()
+{
+  reset_terrain_clearance();
+}
+
 void
 MK_VIII::IOHandler::handle_input_fault (bool test, FaultHandler::Fault fault)
 {
diff --git a/src/Instrumentation/mk_viii.hxx b/src/Instrumentation/mk_viii.hxx
index 594094cf8..517ee49f1 100755
--- a/src/Instrumentation/mk_viii.hxx
+++ b/src/Instrumentation/mk_viii.hxx
@@ -609,6 +609,7 @@ public:
     void update_egpws_alert_discrete_2 ();
     void update_egpwc_alert_discrete_3 ();
     void update_outputs ();
+    void reposition ();
 
     void update_lamps ();
     void set_lamp (Lamp lamp);
@@ -639,7 +640,7 @@ public:
 
     public:
       inline TerrainClearanceFilter ()
-	: value(0) {}
+	: value(0.0), last_update(-1.0) {}
 
       double update (double agl);
       void reset ();
-- 
2.39.5