From bd9ce60174e996d2048f5054859f729efdbab353 Mon Sep 17 00:00:00 2001
From: curt <curt>
Date: Sun, 25 Feb 2001 05:42:34 +0000
Subject: [PATCH] Autopilot in Nav1 heading hold mode is now driven just from
 needle position.

---
 src/Autopilot/newauto.cxx | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/Autopilot/newauto.cxx b/src/Autopilot/newauto.cxx
index d32ee9aeb..407f10ab9 100644
--- a/src/Autopilot/newauto.cxx
+++ b/src/Autopilot/newauto.cxx
@@ -377,6 +377,22 @@ int FGAutopilot::run() {
 	} else if ( heading_mode == FG_HEADING_LOCK ) {
 	    // leave target heading alone
 	} else if ( heading_mode == FG_HEADING_NAV1 ) {
+	    // track the NAV1 heading needle deflection
+	    double cur_radial = current_radiostack->get_nav1_heading() +
+		current_radiostack->get_nav1_magvar();
+	    if ( current_radiostack->get_nav1_from_flag() ) {
+		cur_radial += 180.0;
+		while ( cur_radial >= 360.0 ) { cur_radial -= 360.0; }
+	    }
+	    double adjustment = 
+		current_radiostack->get_nav1_heading_needle_deflection()
+		* (current_radiostack->get_nav1_loc_dist() * METER_TO_NM);
+	    if ( adjustment < -30.0 ) { adjustment = -30.0; }
+	    if ( adjustment >  30.0 ) { adjustment =  30.0; }
+	    TargetHeading = cur_radial + adjustment; 
+	    while ( TargetHeading <   0.0 ) { TargetHeading += 360.0; }
+	    while ( TargetHeading > 360.0 ) { TargetHeading -= 360.0; }
+#if 0
 	    if ( current_radiostack->get_nav1_to_flag() ||
 		 current_radiostack->get_nav1_from_flag() ) {
 		// We have an appropriate radial selected that the
@@ -419,6 +435,7 @@ int FGAutopilot::run() {
 		// neither TO, or FROM, maintain current heading.
 		TargetHeading = FGBFI::getHeading();
 	    }
+#endif
 	    MakeTargetHeadingStr( TargetHeading );
 	    // cout << "target course (true) = " << TargetHeading << endl;
 	} else if ( heading_mode == FG_HEADING_WAYPOINT ) {
-- 
2.39.5