ADF: code clean-up/documentation

[flightgear.git] / src / Instrumentation / heading_indicator_fg.cxx

diff --git a/src/Instrumentation/heading_indicator_fg.cxx b/src/Instrumentation/heading_indicator_fg.cxx
index e35df2d63d3dd754495d9be8685d1ecca18492ac..406300f12f01b158fb1519cead55d11a6a2ad28d 100644 (file)
--- a/src/Instrumentation/heading_indicator_fg.cxx
+++ b/src/Instrumentation/heading_indicator_fg.cxx
@@ -5,15 +5,24 @@
 //
 // This file is in the Public Domain and comes with no warranty.
 
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
 #include <simgear/compiler.h>
 #include <iostream>
 #include <string>
 #include <sstream>
 
-#include "heading_indicator_fg.hxx"
+#include <simgear/magvar/magvar.hxx>
+#include <simgear/math/SGMath.hxx>
+
 #include <Main/fg_props.hxx>
-#include <Main/util.hxx>                           
+#include <Main/util.hxx>
 
+#include "heading_indicator_fg.hxx"
+
+using std::string;
 
 HeadingIndicatorFG::HeadingIndicatorFG ( SGPropertyNode *node )
     :
@@ -53,12 +62,18 @@ HeadingIndicatorFG::init ()
     branch = "/instrumentation/" + name;
     
        _heading_in_node = fgGetNode("/orientation/heading-deg", true);
+
     SGPropertyNode *node = fgGetNode(branch.c_str(), num, true );
-    _offset_node = node->getChild("offset-deg", 0, true);
+    if( NULL == (_offset_node = node->getChild("offset-deg", 0, false)) ) {
+      _offset_node = node->getChild("offset-deg", 0, true);
+      _offset_node->setDoubleValue( -globals->get_mag()->get_magvar() * SGD_RADIANS_TO_DEGREES );
+    }
     _serviceable_node = node->getChild("serviceable", 0, true);
        _error_node = node->getChild("heading-bug-error-deg", 0, true);
        _nav1_error_node = node->getChild("nav1-course-error-deg", 0, true);
     _heading_out_node = node->getChild("indicated-heading-deg", 0, true);
+    _off_node         = node->getChild("off-flag", 0, true);
+
     _last_heading_deg = (_heading_in_node->getDoubleValue() +
                          _offset_node->getDoubleValue());
        _electrical_node = fgGetNode("/systems/electrical/outputs/DG", true);
@@ -96,13 +111,18 @@ HeadingIndicatorFG::update (double dt)
 {
                                 // Get the spin from the gyro
         _gyro.set_power_norm(_electrical_node->getDoubleValue());
-
        _gyro.update(dt);
     double spin = _gyro.get_spin_norm();
 
+    if ( _electrical_node->getDoubleValue() > 0 && spin >= 0.25) {
+        _off_node->setBoolValue(false);
+    } else {
+        _off_node->setBoolValue(true);
+        return;
+    }
+
                                 // No time-based precession    for a flux gate compass
                                    // We just use offset to get the magvar
-
        double offset = _offset_node->getDoubleValue();
           
                                 // TODO: movement-induced error
@@ -115,18 +135,19 @@ HeadingIndicatorFG::update (double dt)
                                 // Now, we have to get the current
                                 // heading and the last heading into
                                 // the same range.
-    while ((heading - _last_heading_deg) > 180)
+    if ((heading - _last_heading_deg) > 180)
         _last_heading_deg += 360;
-    while ((heading - _last_heading_deg) < -180)
+    if ((heading - _last_heading_deg) < -180)
         _last_heading_deg -= 360;
 
     heading = fgGetLowPass(_last_heading_deg, heading, dt * factor);
     _last_heading_deg = heading;
 
        heading += offset;
-    while (heading < 0)
+
+    if (heading < 0)
         heading += 360;
-    while (heading > 360)
+    if (heading > 360)
         heading -= 360;
 
     _heading_out_node->setDoubleValue(heading);