]> git.mxchange.org Git - flightgear.git/blobdiff - src/Main/options.cxx
Erik Hofman:
[flightgear.git] / src / Main / options.cxx
index 4e94992ee846af86a2a01af0d0c478dc90789718..6cb98fc5adb464704f089c1220e489e3b0f54893 100644 (file)
 #include <simgear/compiler.h>
 #include <simgear/misc/exception.hxx>
 
-#include <math.h>            // rint()
+#include <math.h>              // rint()
 #include <stdio.h>
-#include <stdlib.h>          // atof(), atoi()
-#include <string.h>
+#include <stdlib.h>            // atof(), atoi()
+#include <string.h>            // strcmp()
 
 #include STL_STRING
 
 #include <simgear/misc/sgstream.hxx>
+#include <simgear/misc/sg_path.hxx>
+#include <simgear/route/route.hxx>
+#include <simgear/route/waypoint.hxx>
 
 // #include <Include/general.hxx>
 // #include <Airports/simple.hxx>
@@ -112,9 +115,9 @@ fgSetDefaults ()
        // Otherwise, default to Scenery being in $FG_ROOT/Scenery
        globals->set_fg_scenery("");
     }
-                               // Position (Globe, AZ)
-    fgSetDouble("/position/longitude-deg", -110.6642444);
-    fgSetDouble("/position/latitude-deg", 33.3528917);
+                               // Position (deliberately out of range)
+    fgSetDouble("/position/longitude-deg", 9999.0);
+    fgSetDouble("/position/latitude-deg", 9999.0);
     fgSetDouble("/position/altitude-ft", -9999.0);
 
                                // Orientation
@@ -150,7 +153,7 @@ fgSetDefaults ()
                                // Features
     fgSetBool("/sim/hud/visibility", false);
     fgSetBool("/sim/panel/visibility", true);
-    fgSetBool("/sim/sound", true);
+    fgSetBool("/sim/sound/audible", true);
     fgSetBool("/sim/hud/antialiased", false);
 
                                // Flight Model options
@@ -164,7 +167,6 @@ fgSetDefaults ()
                                // Rendering options
     fgSetString("/sim/rendering/fog", "nicest");
     fgSetBool("/environment/clouds/status", true);
-    fgSetDouble("/environment/clouds/altitude-ft", 5000);
     fgSetBool("/sim/startup/fullscreen", false);
     fgSetBool("/sim/rendering/shading", true);
     fgSetBool("/sim/rendering/skyblend", true);
@@ -174,7 +176,7 @@ fgSetDefaults ()
     fgSetInt("/sim/startup/ysize", 600);
     fgSetInt("/sim/rendering/bits-per-pixel", 16);
     fgSetString("/sim/view-mode", "pilot");
-    fgSetDouble("/sim/view/offset-deg", 0);
+    fgSetDouble("/sim/current-view/heading-offset-deg", 0);
     fgSetDouble("/environment/visibility-m", 20000);
 
                                // HUD options
@@ -184,6 +186,7 @@ fgSetDefaults ()
                                // Time options
     fgSetInt("/sim/startup/time-offset", 0);
     fgSetString("/sim/startup/time-offset-type", "system-offset");
+    fgSetLong("/sim/time/cur-time-override", 0);
 
     fgSetBool("/sim/networking/network-olk", false);
     fgSetString("/sim/networking/call-sign", "Johnny");
@@ -191,11 +194,37 @@ fgSetDefaults ()
                                 // Freeze options
     fgSetBool("/sim/freeze/master", false);
     fgSetBool("/sim/freeze/position", false);
-    fgSetBool("/sim/freeze/time-of-day", false);
+    fgSetBool("/sim/freeze/clock", false);
     fgSetBool("/sim/freeze/fuel", false);
 }
 
 
+static bool
+parse_wind (const string &wind, double * min_hdg, double * max_hdg,
+           double * speed, double * gust)
+{
+  unsigned int pos = wind.find('@');
+  if (pos == string::npos)
+    return false;
+  string dir = wind.substr(0, pos);
+  string spd = wind.substr(pos+1);
+  pos = dir.find(':');
+  if (pos == string::npos) {
+    *min_hdg = *max_hdg = atof(dir.c_str());
+  } else {
+    *min_hdg = atof(dir.substr(0,pos).c_str());
+    *max_hdg = atof(dir.substr(pos+1).c_str());
+  }
+  pos = spd.find(':');
+  if (pos == string::npos) {
+    *speed = *gust = atof(spd.c_str());
+  } else {
+    *speed = atof(spd.substr(0,pos).c_str());
+    *gust = atof(spd.substr(pos+1).c_str());
+  }
+  return true;
+}
+
 // parse a time string ([+/-]%f[:%f[:%f]]) into hours
 static double
 parse_time(const string& time_in) {
@@ -423,7 +452,7 @@ parse_fov( const string& arg ) {
     if ( fov < FG_FOV_MIN ) { fov = FG_FOV_MIN; }
     if ( fov > FG_FOV_MAX ) { fov = FG_FOV_MAX; }
 
-    fgSetDouble("/sim/field-of-view", fov);
+    fgSetDouble("/sim/current-view/field-of-view", fov);
 
     // printf("parse_fov(): result = %.4f\n", fov);
 
@@ -478,7 +507,7 @@ parse_wp( const string& arg ) {
        alt_str = arg.substr( pos + 1 );
        // cout << "id str = " << id << "  alt str = " << alt_str << endl;
        alt = atof( alt_str.c_str() );
-       if ( fgGetString("/sim/startup/units") == "feet" ) {
+       if ( !strcmp(fgGetString("/sim/startup/units"), "feet") ) {
            alt *= SG_FEET_TO_METER;
        }
     } else {
@@ -561,22 +590,22 @@ parse_option (const string& arg)
         fgSetBool("/sim/freeze/fuel", false);
     } else if ( arg == "--enable-fuel-freeze" ) {
         fgSetBool("/sim/freeze/fuel", true);
-    } else if ( arg == "--disable-tod-freeze" ) {
-        fgSetBool("/sim/freeze/time-of-day", false);
-    } else if ( arg == "--enable-tod-freeze" ) {
-        fgSetBool("/sim/freeze/time-of-day", true);
+    } else if ( arg == "--disable-clock-freeze" ) {
+        fgSetBool("/sim/freeze/clock", false);
+    } else if ( arg == "--enable-clock-freeze" ) {
+        fgSetBool("/sim/freeze/clock", true);
     } else if ( arg == "--disable-anti-alias-hud" ) {
        fgSetBool("/sim/hud/antialiased", false);
     } else if ( arg == "--enable-anti-alias-hud" ) {
         fgSetBool("/sim/hud/antialiased", true);
     } else if ( arg.find( "--control=") == 0 ) {
-        fgSetString("/sim/control-mode", arg.substr(10));
+        fgSetString("/sim/control-mode", arg.substr(10).c_str());
     } else if ( arg == "--disable-auto-coordination" ) {
         fgSetBool("/sim/auto-coordination", false);
     } else if ( arg == "--enable-auto-coordination" ) {
        fgSetBool("/sim/auto-coordination", true);
     } else if ( arg.find( "--browser-app=") == 0 ) {
-       fgSetString("/sim/startup/browser-app", arg.substr(14));
+       fgSetString("/sim/startup/browser-app", arg.substr(14).c_str());
     } else if ( arg == "--disable-hud" ) {
        fgSetBool("/sim/hud/visibility", false);
     } else if ( arg == "--enable-hud" ) {
@@ -586,12 +615,12 @@ parse_option (const string& arg)
     } else if ( arg == "--enable-panel" ) {
        fgSetBool("/sim/panel/visibility", true);
     } else if ( arg == "--disable-sound" ) {
-       fgSetBool("/sim/sound", false);
+       fgSetBool("/sim/sound/audible", false);
     } else if ( arg == "--enable-sound" ) {
-       fgSetBool("/sim/sound", true);
+       fgSetBool("/sim/sound/audible", true);
     } else if ( arg.find( "--airport-id=") == 0 ) {
                                // NB: changed property name!!!
-       fgSetString("/sim/startup/airport-id", arg.substr(13));
+       fgSetString("/sim/startup/airport-id", arg.substr(13).c_str());
     } else if ( arg.find( "--offset-distance=") == 0 ) {
        fgSetDouble("/sim/startup/offset-distance", atof(arg.substr(18)));
     } else if ( arg.find( "--offset-azimuth=") == 0 ) {
@@ -606,49 +635,49 @@ parse_option (const string& arg)
        fgSetString("/sim/startup/airport-id", "");
     } else if ( arg.find( "--altitude=" ) == 0 ) {
        fgSetBool("/sim/startup/onground", false);
-       if ( fgGetString("/sim/startup/units") == "feet" )
+       if ( !strcmp(fgGetString("/sim/startup/units"), "feet") )
            fgSetDouble("/position/altitude-ft", atof(arg.substr(11)));
        else
            fgSetDouble("/position/altitude-ft",
                        atof(arg.substr(11)) * SG_METER_TO_FEET);
     } else if ( arg.find( "--uBody=" ) == 0 ) {
         fgSetString("/sim/startup/speed-set", "UVW");
-       if ( fgGetString("/sim/startup/units") == "feet" )
+       if ( !strcmp(fgGetString("/sim/startup/units"), "feet") )
          fgSetDouble("/velocities/uBody-fps", atof(arg.substr(8)));
        else
          fgSetDouble("/velocities/uBody-fps",
                               atof(arg.substr(8)) * SG_METER_TO_FEET);
     } else if ( arg.find( "--vBody=" ) == 0 ) {
         fgSetString("/sim/startup/speed-set", "UVW");
-       if ( fgGetString("/sim/startup/units") == "feet" )
+       if ( !strcmp(fgGetString("/sim/startup/units"), "feet") )
          fgSetDouble("/velocities/vBody-fps", atof(arg.substr(8)));
        else
          fgSetDouble("/velocities/vBody-fps",
                               atof(arg.substr(8)) * SG_METER_TO_FEET);
     } else if ( arg.find( "--wBody=" ) == 0 ) {
         fgSetString("/sim/startup/speed-set", "UVW");
-       if ( fgGetString("/sim/startup/units") == "feet" )
+       if ( !strcmp(fgGetString("/sim/startup/units"), "feet") )
          fgSetDouble("/velocities/wBody-fps", atof(arg.substr(8)));
        else
          fgSetDouble("/velocities/wBody-fps",
                               atof(arg.substr(8)) * SG_METER_TO_FEET);
     } else if ( arg.find( "--vNorth=" ) == 0 ) {
         fgSetString("/sim/startup/speed-set", "NED");
-       if ( fgGetString("/sim/startup/units") == "feet" )
+       if ( !strcmp(fgGetString("/sim/startup/units"), "feet") )
          fgSetDouble("/velocities/speed-north-fps", atof(arg.substr(9)));
        else
          fgSetDouble("/velocities/speed-north-fps",
                               atof(arg.substr(9)) * SG_METER_TO_FEET);
     } else if ( arg.find( "--vEast=" ) == 0 ) {
         fgSetString("/sim/startup/speed-set", "NED");
-       if ( fgGetString("/sim/startup/units") == "feet" )
+       if ( !strcmp(fgGetString("/sim/startup/units"), "feet") )
          fgSetDouble("/velocities/speed-east-fps", atof(arg.substr(8)));
        else
          fgSetDouble("/velocities/speed-east-fps",
                      atof(arg.substr(8)) * SG_METER_TO_FEET);
     } else if ( arg.find( "--vDown=" ) == 0 ) {
         fgSetString("/sim/startup/speed-set", "NED");
-       if ( fgGetString("/sim/startup/units") == "feet" )
+       if ( !strcmp(fgGetString("/sim/startup/units"), "feet") )
          fgSetDouble("/velocities/speed-down-fps", atof(arg.substr(8)));
        else
          fgSetDouble("/velocities/speed-down-fps",
@@ -665,16 +694,21 @@ parse_option (const string& arg)
        fgSetDouble("/orientation/roll-deg", atof(arg.substr(7)));
     } else if ( arg.find( "--pitch=" ) == 0 ) {
        fgSetDouble("/orientation/pitch-deg", atof(arg.substr(8)));
+    } else if ( arg.find( "--glideslope=" ) == 0 ) {
+       fgSetDouble("/velocities/glideslope", atof(arg.substr(13))
+                                          *SG_DEGREES_TO_RADIANS);
+    }  else if ( arg.find( "--roc=" ) == 0 ) {
+       fgSetDouble("/velocities/vertical-speed-fps", atof(arg.substr(6))/60);
     } else if ( arg.find( "--fg-root=" ) == 0 ) {
        globals->set_fg_root(arg.substr( 10 ));
     } else if ( arg.find( "--fg-scenery=" ) == 0 ) {
         globals->set_fg_scenery(arg.substr( 13 ));
     } else if ( arg.find( "--fdm=" ) == 0 ) {
-       fgSetString("/sim/flight-model", arg.substr(6));
+       fgSetString("/sim/flight-model", arg.substr(6).c_str());
     } else if ( arg.find( "--aero=" ) == 0 ) {
-       fgSetString("/sim/aero", arg.substr(7));
+       fgSetString("/sim/aero", arg.substr(7).c_str());
     } else if ( arg.find( "--aircraft-dir=" ) == 0 ) {
-        fgSetString("/sim/aircraft-dir", arg.substr(15));
+        fgSetString("/sim/aircraft-dir", arg.substr(15).c_str());
     } else if ( arg.find( "--model-hz=" ) == 0 ) {
        fgSetInt("/sim/model-hz", atoi(arg.substr(11)));
     } else if ( arg.find( "--speed=" ) == 0 ) {
@@ -697,14 +731,6 @@ parse_option (const string& arg)
         fgSetBool("/environment/clouds/status", false);
     } else if ( arg == "--enable-clouds" ) {
         fgSetBool("/environment/clouds/status", true);
-    } else if ( arg.find( "--clouds-asl=" ) == 0 ) {
-                               // FIXME: check units
-        if ( fgGetString("/sim/startup/units") == "feet" )
-         fgSetDouble("/environment/clouds/altitude-ft",
-                               atof(arg.substr(13)));
-       else
-         fgSetDouble("/environment/clouds/altitude-ft",
-                               atof(arg.substr(13)) * SG_METER_TO_FEET);
     } else if ( arg.find( "--fov=" ) == 0 ) {
        parse_fov( arg.substr(6) );
     } else if ( arg == "--disable-fullscreen" ) {
@@ -773,25 +799,20 @@ parse_option (const string& arg)
        fgSetString("/sim/startup/units", "meters");
     } else if ( arg.find( "--time-offset" ) == 0 ) {
         fgSetInt("/sim/startup/time-offset",
-                          parse_time_offset( (arg.substr(14)) ));
+                 parse_time_offset( (arg.substr(14)) ));
+       fgSetString("/sim/startup/time-offset-type", "system-offset");
     } else if ( arg.find( "--time-match-real") == 0 ) {
-        fgSetString("/sim/startup/time-offset-type",
-                             "system-offset");
+        fgSetString("/sim/startup/time-offset-type", "system-offset");
     } else if ( arg.find( "--time-match-local") == 0 ) {
-        fgSetString("/sim/startup/time-offset-type",
-                             "latitude-offset");
+        fgSetString("/sim/startup/time-offset-type", "latitude-offset");
     } else if ( arg.find( "--start-date-sys=") == 0 ) {
-        fgSetInt("/sim/startup/time-offset",
-                          parse_date((arg.substr(17))));
+        fgSetInt("/sim/startup/time-offset", parse_date((arg.substr(17))));
        fgSetString("/sim/startup/time-offset-type", "system");
     } else if ( arg.find( "--start-date-lat=") == 0 ) {
-        fgSetInt("/sim/startup/time-offset",
-                          parse_date((arg.substr(17))));
-       fgSetString("/sim/startup/time-offset-type",
-                          "latitude");
+        fgSetInt("/sim/startup/time-offset", parse_date((arg.substr(17))));
+       fgSetString("/sim/startup/time-offset-type", "latitude");
     } else if ( arg.find( "--start-date-gmt=") == 0 ) {
-        fgSetInt("/sim/startup/time-offset",
-                          parse_date((arg.substr(17))));
+        fgSetInt("/sim/startup/time-offset", parse_date((arg.substr(17))));
        fgSetString("/sim/startup/time-offset-type", "gmt");
     } else if ( arg == "--hud-tris" ) {
         fgSetString("/sim/hud/frame-stat-type", "tris");
@@ -823,6 +844,8 @@ parse_option (const string& arg)
        add_channel( "nmea", arg.substr(7) );
     } else if ( arg.find( "--props=" ) == 0 ) {
        add_channel( "props", arg.substr(8) );
+    } else if ( arg.find( "--telnet=" ) == 0 ) {
+       add_channel( "telnet", arg.substr(9) );
     } else if ( arg.find( "--pve=" ) == 0 ) {
        add_channel( "pve", arg.substr(6) );
     } else if ( arg.find( "--ray=" ) == 0 ) {
@@ -840,7 +863,7 @@ parse_option (const string& arg)
         fgSetBool("/sim/hud/net-display", true);
        net_hud_display = 1;    // FIXME
     } else if ( arg.find( "--net-id=") == 0 ) {
-        fgSetString("sim/networking/call-sign", arg.substr(9));
+        fgSetString("sim/networking/call-sign", arg.substr(9).c_str());
 #endif
     } else if ( arg.find( "--prop:" ) == 0 ) {
         string assign = arg.substr(7);
@@ -851,17 +874,19 @@ parse_option (const string& arg)
        }
        string name = assign.substr(0, pos);
        string value = assign.substr(pos + 1);
-       fgSetString(name.c_str(), value);
+       fgSetString(name.c_str(), value.c_str());
        // SG_LOG(SG_GENERAL, SG_INFO, "Setting default value of property "
        //        << name << " to \"" << value << '"');
     } else if ( arg.find("--trace-read=") == 0) {
         string name = arg.substr(13);
        SG_LOG(SG_GENERAL, SG_INFO, "Tracing reads for property " << name);
-       fgGetNode(name, true)->setAttribute(SGPropertyNode::TRACE_READ, true);
+       fgGetNode(name.c_str(), true)
+         ->setAttribute(SGPropertyNode::TRACE_READ, true);
     } else if ( arg.find("--trace-write=") == 0) {
         string name = arg.substr(14);
        SG_LOG(SG_GENERAL, SG_INFO, "Tracing writes for property " << name);
-       fgGetNode(name, true)->setAttribute(SGPropertyNode::TRACE_WRITE, true);
+       fgGetNode(name.c_str(), true)
+         ->setAttribute(SGPropertyNode::TRACE_WRITE, true);
     } else if ( arg.find( "--view-offset=" ) == 0 ) {
         // $$$ begin - added VS Renganathan, 14 Oct 2K
         // for multi-window outside window imagery
@@ -876,11 +901,11 @@ parse_option (const string& arg)
        } else {
            default_view_offset = atof( woffset.c_str() ) * SGD_DEGREES_TO_RADIANS;
        }
-       FGViewerRPH *pilot_view =
-           (FGViewerRPH *)globals->get_viewmgr()->get_view( 0 );
-       pilot_view->set_view_offset( default_view_offset );
-       pilot_view->set_goal_view_offset( default_view_offset );
-       fgSetDouble("/sim/view/offset-deg", default_view_offset);
+       FGViewer *pilot_view =
+           (FGViewer *)globals->get_viewmgr()->get_view( 0 );
+        // this will work without calls to the viewer...
+       fgSetDouble( "/sim/current-view/heading-offset-deg",
+                     default_view_offset  * SGD_RADIANS_TO_DEGREES );
     // $$$ end - added VS Renganathan, 14 Oct 2K
     } else if ( arg.find( "--visibility=" ) == 0 ) {
        fgSetDouble("/environment/visibility-m", atof(arg.substr(13)));
@@ -888,29 +913,39 @@ parse_option (const string& arg)
         double visibility = atof(arg.substr(19)) * 5280.0 * SG_FEET_TO_METER;
        fgSetDouble("/environment/visibility-m", visibility);
     } else if ( arg.find( "--wind=" ) == 0 ) {
+        double min_hdg, max_hdg, speed, gust;
+        if (!parse_wind(arg.substr(7), &min_hdg, &max_hdg, &speed, &gust)) {
+         SG_LOG( SG_GENERAL, SG_ALERT, "bad wind value " << arg.substr(7) );
+         return FG_OPTIONS_ERROR;
+       }
+       fgSetDouble("/environment/wind-from-heading-deg", min_hdg);
+       fgSetDouble("/environment/params/min-wind-from-heading-deg", min_hdg);
+       fgSetDouble("/environment/params/max-wind-from-heading-deg", max_hdg);
+       fgSetDouble("/environment/wind-speed-kt", speed);
+       fgSetDouble("/environment/params/base-wind-speed-kt", speed);
+       fgSetDouble("/environment/params/gust-wind-speed-kt", gust);
+
         string val = arg.substr(7);
        unsigned int pos = val.find('@');
        if ( pos == string::npos ) {
          SG_LOG( SG_GENERAL, SG_ALERT, "bad wind value " << val );
          return FG_OPTIONS_ERROR;
        }
-       double dir = atof(val.substr(0,pos).c_str());
-       double speed = atof(val.substr(pos+1).c_str());
-       SG_LOG(SG_GENERAL, SG_INFO, "WIND: " << dir << '@' << 
+       SG_LOG(SG_GENERAL, SG_INFO, "WIND: " << min_hdg << '@' << 
               speed << " knots" << endl);
-       fgSetDouble("/environment/wind-from-heading-deg", dir);
-       fgSetDouble("/environment/wind-speed-knots", speed);
 
+#ifdef FG_WEATHERCM
         // convert to fps
        speed *= SG_NM_TO_METER * SG_METER_TO_FEET * (1.0/3600);
-       // dir += 180;
-       if (dir >= 360)
-         dir -= 360;
-       dir *= SGD_DEGREES_TO_RADIANS;
-       fgSetDouble("/environment/wind-north-fps",
-                   speed * cos(dir));
-       fgSetDouble("/environment/wind-east-fps",
-                   speed * sin(dir));
+       while (min_hdg > 360)
+         min_hdg -= 360;
+       while (min_hdg <= 0)
+         min_hdg += 360;
+       min_hdg *= SGD_DEGREES_TO_RADIANS;
+       fgSetDouble("/environment/wind-from-north-fps", speed * cos(dir));
+       fgSetDouble("/environment/wind-from-east-fps", speed * sin(dir));
+#endif // FG_WEATHERCM
+
     } else if ( arg.find( "--wp=" ) == 0 ) {
        parse_wp( arg.substr( 5 ) );
     } else if ( arg.find( "--flight-plan=") == 0) {
@@ -931,14 +966,9 @@ parse_option (const string& arg)
         apath.append( "Aircraft" );
         apath.append( arg.substr(11) );
         apath.concat( "-set.xml" );
-        try {
-            readProperties( apath.str(), globals->get_props() );
-        } catch (const sg_exception &e) {
-            string message = "Error loading aircraft file: ";
-            message += e.getFormattedMessage();
-            SG_LOG(SG_INPUT, SG_ALERT, message);
-            exit(2);
-        }
+       SG_LOG(SG_INPUT, SG_INFO, "Reading aircraft: " << arg.substr(11)
+           << " from " << apath.str());
+       readProperties( apath.str(), globals->get_props() );
     } else {
        SG_LOG( SG_GENERAL, SG_ALERT, "Unknown option '" << arg << "'" );
        return FG_OPTIONS_ERROR;
@@ -1095,193 +1125,83 @@ fgParseOptions (const string& path) {
 void 
 fgUsage ()
 {
-    cout << "Usage: fgfs [ option ... ]" << endl
-         << endl
-
-         << "General Options:" << endl
-         << "    --help, -h                    Print usage" << endl
-         << "    --fg-root=path                Specify the root data path" << endl
-         << "    --fg-scenery=path             Specify the base scenery path;" << endl
-        << "                                  Defaults to $FG_ROOT/Scenery" << endl
-         << "    --disable-game-mode           Disable full-screen game mode" << endl
-         << "    --enable-game-mode            Enable full-screen game mode" << endl
-         << "    --disable-splash-screen       Disable splash screen" << endl
-         << "    --enable-splash-screen        Enable splash screen" << endl
-         << "    --disable-intro-music         Disable introduction music" << endl
-         << "    --enable-intro-music          Enable introduction music" << endl
-         << "    --disable-mouse-pointer       Disable extra mouse pointer" << endl
-         << "    --enable-mouse-pointer        Enable extra mouse pointer (i.e. for full-" << endl
-         << "                                  screen Voodoo based cards)" << endl
-         << "    --disable-freeze              Start in a running state" << endl
-         << "    --enable-freeze               Start in a frozen state" << endl
-         << "    --disable-fuel-freeze         Fuel is consumed normally" << endl
-         << "    --enable-fuel-freeze          Fuel tank quantity forced to remain constant" << endl
-         << "    --disable-tod-freeze          Time of day advances normally" << endl
-         << "    --enable-tod-freeze           Do not advance time of day" << endl
-         << "    --control=mode                Primary control mode (joystick, keyboard," << endl
-         << "                                  mouse)" << endl
-         << "    --enable-auto-coordination    Enable auto coordination" << endl
-         << "    --disable-auto-coordination   Disable auto coordination" << endl
-         << "    --browser-app=path            Specify path to your web browser" << endl
-         << "    --prop:name=value             Set property <name> to <value>" << endl
-         << "    --config=path                 Load additional properties from path" << endl
-         << "    --units-feet                  Use feet for distances" << endl
-         << "    --units-meters                Use meters for distances" << endl
-         << endl
-
-         << "Features:" << endl
-         << "    --disable-hud                 Disable Heads Up Display (HUD)" << endl
-         << "    --enable-hud                  Enable Heads Up Display (HUD)" << endl
-         << "    --disable-panel               Disable instrument panel" << endl
-         << "    --enable-panel                Enable instrument panel" << endl
-         << "    --disable-sound               Disable sound effects" << endl
-         << "    --enable-sound                Enable sound effects" << endl
-         << "    --disable-anti-alias-hud      Disable anti-aliased HUD" << endl
-         << "    --enable-anti-alias-hud       Enable anti-aliased HUD" << endl
-         << endl
-
-         << "Aircraft:" <<endl
-         << "    --aircraft=name               Select an aircraft profile as defined by a" << endl
-         << "                                  top level <name>-set.xml" << endl
-         << endl
-
-         << "Flight Model:" << endl
-         << "    --fdm=name                    Select the core flight dynamics model" << endl
-         << "                                  Can be one of jsb, larcsim, yasim, magic," << endl
-         << "                                  balloon, ada, external, or null" << endl
-         << "    --aero=name                   Select aircraft aerodynamics model to load" << endl
-         << "    --model-hz=n                  Run the FDM this rate (iterations per" << endl
-         << "                                  second)" << endl
-         << "    --speed=n                     Run the FDM 'n' times faster than real time" << endl
-         << "    --notrim                      Do NOT attempt to trim the model (only with" << endl
-         << "                                  fdm=jsbsim)" << endl
-         << "    --on-ground                   Start at ground level (default)" << endl
-         << "    --in-air                      Start in air (implied when using --altitude)" << endl
-         << "    --wind=DIR@SPEED              Specify wind coming from DIR (degrees) at" << endl
-         << "                                  SPEED (knots)" << endl
-         << endl
-
-         << "Aircraft model directory (UIUC FDM ONLY):" << endl
-         << "    --aircraft-dir=path           Aircraft directory relative to the path of" << endl
-         << "                                  the executable" << endl
-         << endl
-
-         << "Initial Position and Orientation:" << endl
-         << "    --airport-id=ID               Specify starting position by airport ID" << endl
-         << "    --offset-distance=nm          Specify distance to threshold" << endl 
-         << "    --offset-azimuth=degrees      Specify heading to threshold" << endl    
-         << "    --lon=degrees                 Starting longitude (west = -)" << endl
-         << "    --lat=degrees                 Starting latitude (south = -)" << endl
-         << "    --altitude=value              Starting altitude (in feet unless" << endl
-         << "                                  --units-meters specified)" << endl
-         << "    --heading=degrees             Specify heading (yaw) angle (Psi)" << endl
-         << "    --roll=degrees                Specify roll angle (Phi)" << endl
-         << "    --pitch=degrees               Specify pitch angle (Theta)" << endl
-         << "    --uBody=units_per_sec         Specify velocity along the body X axis" << endl
-         << "                                  (in feet unless --units-meters specified)" << endl
-         << "    --vBody=units_per_sec         Specify velocity along the body Y axis" << endl
-         << "                                  (in feet unless --units-meters specified)" << endl
-         << "    --wBody=units_per_sec         Specify velocity along the body Z axis" << endl
-         << "                                  (in feet unless --units-meters specified)" << endl
-         << "    --vc=knots                    Specify initial airspeed" << endl
-         << "    --mach=num                    Specify initial mach number" << endl
-         << endl
-
-         << "Rendering Options:" << endl
-         << "    --bpp=depth                   Specify the bits per pixel" << endl
-         << "    --fog-disable                 Disable fog/haze" << endl
-         << "    --fog-fastest                 Enable fastest fog/haze" << endl
-         << "    --fog-nicest                  Enable nicest fog/haze" << endl
-         << "    --enable-clouds               Enable cloud layers" << endl
-         << "    --disable-clouds              Disable cloud layers" << endl
-         << "    --clouds-asl=altitude         Specify altitude of cloud layer above sea" << endl
-         << "                                  level" << endl
-         << "    --fov=degrees                 Specify field of view angle" << endl
-         << "    --disable-fullscreen          Disable fullscreen mode" << endl
-         << "    --enable-fullscreen           Enable fullscreen mode" << endl
-         << "    --shading-flat                Enable flat shading" << endl
-         << "    --shading-smooth              Enable smooth shading" << endl
-         << "    --disable-skyblend            Disable sky blending" << endl
-         << "    --enable-skyblend             Enable sky blending" << endl
-         << "    --disable-textures            Disable textures" << endl
-         << "    --enable-textures             Enable textures" << endl
-         << "    --disable-wireframe           Disable wireframe drawing mode" << endl
-         << "    --enable-wireframe            Enable wireframe drawing mode" << endl
-         << "    --geometry=WxH                Specify window geometry (640x480, etc)" << endl
-         << "    --view-offset=value           Specify the default forward view direction" << endl
-         << "                                  as an offset from straight ahead.  Allowable" << endl
-         << "                                  values are LEFT, RIGHT, CENTER, or a specific" << endl
-         << "                                  number in degrees" << endl
-         << "    --visibility=meters           Specify initial visibility" << endl
-         << "    --visibility-miles=miles      Specify initial visibility in miles" << endl
-         << endl
-
-         << "Hud Options:" << endl
-         << "    --hud-tris                    Hud displays number of triangles rendered" << endl
-         << "    --hud-culled                  Hud displays percentage of triangles culled" << endl
-         << endl
-       
-         << "Time Options:" << endl
-         << "    --time-offset=[+-]hh:mm:ss    Add this time offset; can be use in" << endl
-         << "                                  combination with other time options" << endl
-         << "    --time-match-real             Synchronize time with real-world time" << endl
-         << "    --time-match-local            Synchronize time with local real-world time" << endl
-         << "    --start-date-sys=yyyy:mm:dd:hh:mm:ss" << endl
-         << "                                  Specify a starting date/time with respect to" << endl
-         << "                                  system time" << endl
-         << "    --start-date-gmt=yyyy:mm:dd:hh:mm:ss" << endl
-         << "                                  Specify a starting date/time with respect to" << endl
-         << "                                  Greenwich Mean Time" << endl
-         << "    --start-date-lat=yyyy:mm:dd:hh:mm:ss" << endl
-         << "                                  Specify a starting date/time with respect to" << endl
-         << "                                  Local Aircraft Time" << endl
-         << endl
-
-         << "Network Options:" << endl
-         << "    --httpd=port                  Enable http server on the specified port" << endl
-#ifdef FG_JPEG_SERVER
-         << "    --jpg-httpd=port              Enable screen shot http server on the" << endl
-         << "                                  specified port" << endl
-#endif
-#ifdef FG_NETWORK_OLK
-         << "    --disable-network-olk         Disable Multipilot mode (default)" << endl
-         << "    --enable-network-olk          Enable Multipilot mode" << endl
-         << "    --net-hud                     Hud displays network info" << endl
-         << "    --net-id=name                 Specify your own callsign" << endl
-#endif
-         << endl
-
-         << "Route/Way Point Options:" << endl
-         << "    --wp=ID[@alt]                 Specify a waypoint for the GC autopilot;" << endl
-         << "                                  multiple instances can be used to create a" << endl
-         << "                                  route" << endl
-         << "    --flight-plan=file            Read all waypoints from a file" << endl
-         << endl
-
-         << "IO Options:" << endl
-         << "    --gamin=params                Open connection using the Garmin GPS protocol" << endl
-         << "    --joyclient=params            Open connection to an Agwagon joystick" << endl
-         << "    --native-ctrls=params         Open connection using the FG Native Controls" << endl
-         << "                                  protocol" << endl
-         << "    --native-fdm=params           Open connection using the FG Native FDM" << endl
-         << "                                  protocol" << endl
-         << "    --native=params               Open connection using the FG Native protocol" << endl
-         << "    --nmea=params                 Open connection using the NMEA protocol" << endl
-         << "    --opengc=params               Open connection using the OpenGC protocol" << endl
-         << "    --props=params                Open connection using the interactive" << endl
-         << "                                  property manager" << endl
-         << "    --pve=params                  Open connection using the PVE protocol" << endl
-         << "    --ray=params                  Open connection using the RayWoodworth" << endl
-         << "                                  motion chair protocol" << endl
-         << "    --rul=params                  Open connection using the RUL protocol" << endl
-         << endl
-         << "    --atc610x                     Enable atc610x interface." << endl
-         << endl
-
-         << "Debugging Options:" << endl
-         << "    --trace-read=property         Trace the reads for a property; multiple" << endl
-         << "                                  instances allowed." << endl
-         << "    --trace-write=property        Trace the writes for a property; multiple" << endl
-         << "                                  instances allowed." << endl
-         << endl;
+    // *** FIXME ***
+    // Began the process of converting output from printf() to
+    // SG_LOG() but this needs to be finished.
+
+    SGPropertyNode options_root;
+    SGPath opath( globals->get_fg_root() );
+    opath.append( "options.xml" );
+
+    try {
+        readProperties(opath.c_str(), &options_root);
+    } catch (const sg_exception &ex) {
+        SG_LOG( SG_GENERAL, SG_ALERT, endl << "Unable to read the help file." );
+        SG_LOG( SG_GENERAL, SG_ALERT, "Make sure the file options.xml is located in the FlightGear base directory." );
+        exit(-1);
+    }
+
+    SGPropertyNode *options = options_root.getNode("options");
+    if (!options) {
+        SG_LOG( SG_GENERAL, SG_ALERT,
+                "Error reading options.xml: <options> directive not found." );
+        exit(-1);
+    }
+
+    SGPropertyNode *usage = options->getNode("usage");
+    if (usage) {
+        SG_LOG( SG_GENERAL, SG_ALERT, "Usage: " << usage->getStringValue() );
+    }
+
+    vector<SGPropertyNode_ptr>section = options->getChildren("section");
+    for (unsigned int j = 0; j < section.size(); j++) {
+
+        SGPropertyNode *name = section[j]->getNode("name");
+        if (name) {
+            SG_LOG( SG_GENERAL, SG_ALERT, endl << name->getStringValue()
+                    << ":" );
+        }
+
+        vector<SGPropertyNode_ptr>option = section[j]->getChildren("option");
+        for (unsigned int k = 0; k < option.size(); k++) {
+
+            SGPropertyNode *name = option[k]->getNode("name");
+            SGPropertyNode *short_name = option[k]->getNode("short");
+            SGPropertyNode *arg = option[k]->getNode("arg");
+
+            if (name) {
+                string str = name->getStringValue();
+                if (short_name) {
+                    str.append(", -");
+                    str.append(short_name->getStringValue());
+                }
+                if (arg) {
+                    str.append("=");
+                    str.append(arg->getStringValue());
+                }
+
+                if (str.size() <= 25) {
+                    fprintf(stderr, "   --%-27s", str.c_str());
+                } else {
+                    fprintf(stderr, "\n   --%s\n%32c", str.c_str(), ' ');
+                }
+
+                str.erase();
+                SGPropertyNode *desc = option[k]->getNode("description");
+                if (desc) {
+                    SG_LOG( SG_GENERAL, SG_ALERT, desc->getStringValue() );
+
+                    for ( int l = 1;
+                          (desc = option[k]->getNode("desc", l, false));
+                          l++ )
+                    {
+                        fprintf(stderr, "%32c%s\n", ' ',
+                                desc->getStringValue());
+                    }
+                } else {
+                    SG_LOG( SG_GENERAL, SG_ALERT, "" );
+                }
+            }
+        }
+    }
 }