X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=src%2FAIModel%2FAIEscort.cxx;h=9a816675597d88283aad6a25b43bb5b28472840c;hb=9d995907db00728da7eac9297ecbab93ed8a7400;hp=5ef8485357d04686fb48c5f79eefa41b4282ce55;hpb=bc12f0be21d703653620743b6bf86db7c78a69cd;p=flightgear.git

diff --git a/src/AIModel/AIEscort.cxx b/src/AIModel/AIEscort.cxx
index 5ef848535..9a8166755 100644
--- a/src/AIModel/AIEscort.cxx
+++ b/src/AIModel/AIEscort.cxx
@@ -1,483 +1,382 @@
-// FGAIEscort - FGAIShip-derived class creates an AI Ground Vehicle
-// by adding a ground following utility
-//
-// Written by Vivian Meazza, started August 2009.
-// - vivian.meazza at lineone.net
-//
-// This program is free software; you can redistribute it and/or
-// modify it under the terms of the GNU General Public License as
-// published by the Free Software Foundation; either version 2 of the
-// License, or (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful, but
-// WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-// General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with this program; if not, write to the Free Software
-// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
-
-#ifdef HAVE_CONFIG_H
-#  include <config.h>
-#endif
-
-#include <algorithm>
-#include <string>
-#include <vector>
-
-#include <simgear/sg_inlines.h>
-#include <simgear/math/SGMath.hxx>
-#include <simgear/math/sg_geodesy.hxx>
-
-#include <math.h>
-#include <Main/util.hxx>
-#include <Main/viewer.hxx>
-
-#include <Scenery/scenery.hxx>
-#include <Scenery/tilemgr.hxx>
-
-#include "AIEscort.hxx"
-
-using std::string;
-
-FGAIEscort::FGAIEscort() :
-FGAIShip(otEscort),
-
-_selected_ac(0),
-_relbrg (0),
-_stn_truebrg(0),
-_parent_speed(0),
-_stn_limit(0),
-_stn_angle_limit(0),
-_stn_speed(0),
-_stn_height(0),
-_max_speed(0),
-_interval(0),
-_MPControl(false),
-_patrol(false),
-_stn_deg_true(false),
-_parent("")
-
-{
-    invisible = false;
-}
-
-FGAIEscort::~FGAIEscort() {}
-
-void FGAIEscort::readFromScenario(SGPropertyNode* scFileNode) {
-    if (!scFileNode)
-        return;
-
-    FGAIShip::readFromScenario(scFileNode);
-
-    setName(scFileNode->getStringValue("name", "Escort"));
-    setSMPath(scFileNode->getStringValue("submodel-path", ""));
-    setStnRange(scFileNode->getDoubleValue("station/range-nm", 1));
-    setStnBrg(scFileNode->getDoubleValue("station/brg-deg", 0.0));
-    setStnLimit(scFileNode->getDoubleValue("station/range-limit-nm", 0.2));
-    setStnAngleLimit(scFileNode->getDoubleValue("station/angle-limit-deg", 15.0));
-    setStnSpeed(scFileNode->getDoubleValue("station/speed-kts", 2.5));
-    setStnPatrol(scFileNode->getBoolValue("station/patrol", false));
-    setStnHtFt(scFileNode->getDoubleValue("station/height-ft", 0.0));
-    setStnDegTrue(scFileNode->getBoolValue("station/deg-true", false));
-    setParentName(scFileNode->getStringValue("station/parent", ""));
-    setMaxSpeed(scFileNode->getDoubleValue("max-speed-kts", 30.0));
-    setUpdateInterval(scFileNode->getDoubleValue("update-interval-sec", 10.0));
-    setCallSign(scFileNode->getStringValue("callsign", ""));
-
-    if(_patrol)
-        sg_srandom_time();
-
-}
-
-void FGAIEscort::bind() {
-    FGAIShip::bind();
-
-    props->tie("station/rel-bearing-deg",
-        SGRawValuePointer<double>(&_stn_relbrg));
-    props->tie("station/true-bearing-deg",
-        SGRawValuePointer<double>(&_stn_truebrg));
-    props->tie("station/range-nm",
-        SGRawValuePointer<double>(&_stn_range));
-    props->tie("station/range-limit-nm",
-        SGRawValuePointer<double>(&_stn_limit));
-    props->tie("station/angle-limit-deg",
-        SGRawValuePointer<double>(&_stn_angle_limit));
-    props->tie("station/speed-kts",
-        SGRawValuePointer<double>(&_stn_speed));
-    props->tie("station/height-ft",
-        SGRawValuePointer<double>(&_stn_height));
-    props->tie("controls/update-interval-sec",
-        SGRawValuePointer<double>(&_interval));
-    props->tie("controls/parent-mp-control",
-        SGRawValuePointer<bool>(&_MPControl));
-    props->tie("station/target-range-nm",
-        SGRawValuePointer<double>(&_tgtrange));
-    props->tie("station/target-brg-deg-t",
-        SGRawValuePointer<double>(&_tgtbrg));
-    props->tie("station/patrol",
-        SGRawValuePointer<bool>(&_patrol));
-}
-
-void FGAIEscort::unbind() {
-    FGAIShip::unbind();
-
-    props->untie("station/rel-bearing-deg");
-    props->untie("station/true-bearing-deg");
-    props->untie("station/range-nm");
-    props->untie("station/range-limit-nm");
-    props->untie("station/angle-limit-deg");
-    props->untie("station/speed-kts");
-    props->untie("station/height-ft");
-    props->untie("controls/update-interval-sec");
-
-}
-
-bool FGAIEscort::init(bool search_in_AI_path) {
-    if (!FGAIShip::init(search_in_AI_path))
-        return false;
-
-    invisible = false;
-    no_roll = false;
-
-    props->setStringValue("controls/parent-name", _parent.c_str());
-    setParentNode();
-    pos = _tgtpos;
-    speed = _parent_speed;
-    hdg = _parent_hdg;
-
-    return true;
-}
-
-void FGAIEscort::update(double dt) {
-    FGAIShip::update(dt);
-
-    RunEscort(dt);
-}
-
-void FGAIEscort::setStnRange(double r) {
-    _stn_range = r;
-}
-
-void FGAIEscort::setStnBrg(double b) {
-    _stn_brg = b;
-}
-
-void FGAIEscort::setStnLimit(double l) {
-    _stn_limit = l;
-}
-
-void FGAIEscort::setStnAngleLimit(double al) {
-    _stn_angle_limit = al;
-}
-
-void FGAIEscort::setStnSpeed(double s) {
-    _stn_speed = s;
-}
-
-void FGAIEscort::setStnHtFt(double h) {
-    _stn_height = h;
-}
-
-void FGAIEscort::setStnDegTrue(bool t) {
-    _stn_deg_true = t;
-}
-
-void FGAIEscort::setMaxSpeed(double m) {
-    _max_speed = m;
-}
-
-void FGAIEscort::setUpdateInterval(double i) {
-    _interval = i;
-}
-
-void FGAIEscort::setStnPatrol(bool p) {
-    _patrol = p;
-}
-
-void FGAIEscort::setParentName(const string& p) {
-    _parent = p;
-}
-
-bool FGAIEscort::getGroundElev(SGGeod inpos) {
-
-    double height_m ;
-
-    if (globals->get_scenery()->get_elevation_m(SGGeod::fromGeodM(inpos, 3000), height_m, &_material,0)){
-        _ht_agl_ft = inpos.getElevationFt() - height_m * SG_METER_TO_FEET;
-
-        if (_material) {
-            const vector<string>& names = _material->get_names();
-
-            _solid = _material->get_solid();
-
-            if (!names.empty())
-                props->setStringValue("material/name", names[0].c_str());
-            else
-                props->setStringValue("material/name", "");
-
-            //cout << "material " << names[0].c_str()
-            //    << " _elevation_m " << _elevation_m
-            //    << " solid " << _solid
-            //    << " load " << _load_resistance
-            //    << " frictionFactor " << _frictionFactor
-            //    << endl;
-
-        }
-
-        return true;
-    } else {
-        return false;
-    }
-
-}
-
-void FGAIEscort::setParentNode() {
-
-    const SGPropertyNode_ptr ai = fgGetNode("/ai/models", true);
-
-    for (int i = ai->nChildren() - 1; i >= -1; i--) {
-        SGPropertyNode_ptr model;
-
-        if (i < 0) { // last iteration: selected model
-            model = _selected_ac;
-        } else {
-            model = ai->getChild(i);
-            string path = ai->getPath();
-            const string name = model->getStringValue("name");
-
-            if (!model->nChildren()){
-                continue;
-            }
-            if (name == _parent) {
-                _selected_ac = model;  // save selected model for last iteration
-                break;
-            }
-
-        }
-        if (!model)
-            continue;
-
-    }// end for loop
-
-    if (_selected_ac != 0){
-        const string name = _selected_ac->getStringValue("name");
-        setParent();
-
-        //double lat = _selected_ac->getDoubleValue("position/latitude-deg");
-        //double lon = _selected_ac->getDoubleValue("position/longitude-deg");
-        //double elevation = _selected_ac->getDoubleValue("position/altitude-ft");
-        //_MPControl = _selected_ac->getBoolValue("controls/mp-control");
-
-        //_selectedpos.setLatitudeDeg(lat);
-        //_selectedpos.setLongitudeDeg(lon);
-        //_selectedpos.setElevationFt(elevation);
-
-        //_parent_speed    = _selected_ac->getDoubleValue("velocities/speed-kts");
-        //_parent_hdg      = _selected_ac->getDoubleValue("orientation/true-heading-deg");
-
-        //if(!_stn_deg_true){
-        //    _stn_truebrg = calcTrueBearingDeg(_stn_brg, _parent_hdg);
-        //    _stn_relbrg = _stn_brg;
-        //    //cout << _name <<" set rel"<<endl;
-        //} else {
-        //    _stn_truebrg = _stn_brg;
-        //    _stn_relbrg = calcRelBearingDeg(_stn_brg, _parent_hdg); 
-        //    //cout << _name << " set true"<<endl;
-        //}
-
-        //double course2;
-
-        //SGGeodesy::direct( _selectedpos, _stn_truebrg, _stn_range * SG_NM_TO_METER,
-        //    _tgtpos, course2);
-
-        //_tgtpos.setElevationFt(_stn_height);
-
-        //calcRangeBearing(pos.getLatitudeDeg(), pos.getLongitudeDeg(),
-        //    _tgtpos.getLatitudeDeg(), _tgtpos.getLongitudeDeg(), _tgtrange, _tgtbrg);
-
-        //_relbrg = calcRelBearingDeg(_tgtbrg, hdg);
-
-    } else {
-        SG_LOG(SG_GENERAL, SG_ALERT, "AIEscort: " << _name
-            << " parent not found: dying ");
-        setDie(true);
-    }
-
-}
-
-void FGAIEscort::setParent()
-{
-    double lat = _selected_ac->getDoubleValue("position/latitude-deg");
-    double lon = _selected_ac->getDoubleValue("position/longitude-deg");
-    double elevation = _selected_ac->getDoubleValue("position/altitude-ft");
-    _MPControl = _selected_ac->getBoolValue("controls/mp-control");
-
-    _selectedpos.setLatitudeDeg(lat);
-    _selectedpos.setLongitudeDeg(lon);
-    _selectedpos.setElevationFt(elevation);
-
-    _parent_speed    = _selected_ac->getDoubleValue("velocities/speed-kts");
-    _parent_hdg      = _selected_ac->getDoubleValue("orientation/true-heading-deg");
-
-    if(!_stn_deg_true){
-        _stn_truebrg = calcTrueBearingDeg(_stn_brg, _parent_hdg);
-        _stn_relbrg = _stn_brg;
-        //cout << _name <<" set rel"<<endl;
-    } else {
-        _stn_truebrg = _stn_brg;
-        _stn_relbrg = calcRelBearingDeg(_stn_brg, _parent_hdg); 
-        //cout << _name << " set true"<<endl;
-    }
-
-            double course2;
-
-        SGGeodesy::direct( _selectedpos, _stn_truebrg, _stn_range * SG_NM_TO_METER,
-            _tgtpos, course2);
-
-        _tgtpos.setElevationFt(_stn_height);
-
-        calcRangeBearing(pos.getLatitudeDeg(), pos.getLongitudeDeg(),
-            _tgtpos.getLatitudeDeg(), _tgtpos.getLongitudeDeg(), _tgtrange, _tgtbrg);
-
-        _relbrg = calcRelBearingDeg(_tgtbrg, hdg);
-
-}
-
-void FGAIEscort::calcRangeBearing(double lat, double lon, double lat2, double lon2,
-                                  double &range, double &bearing) const
-{
-    // calculate the bearing and range of the second pos from the first
-    double az2, distance;
-    geo_inverse_wgs_84(lat, lon, lat2, lon2, &bearing, &az2, &distance);
-    range = distance * SG_METER_TO_NM;
-}
-
-double FGAIEscort::calcRelBearingDeg(double bearing, double heading)
-{
-    double angle = bearing - heading;
-    SG_NORMALIZE_RANGE(angle, -180.0, 180.0);
-    return angle;
-}
-
-double FGAIEscort::calcTrueBearingDeg(double bearing, double heading)
-{
-    double angle = bearing + heading;
-    SG_NORMALIZE_RANGE(angle, 0.0, 360.0);
-    return angle;
-}
-
-double FGAIEscort::calcRecipBearingDeg(double bearing)
-{
-    double angle = bearing - 180;
-    SG_NORMALIZE_RANGE(angle, 0.0, 360.0);
-    return angle;
-}
-
-SGVec3d FGAIEscort::getCartHitchPosAt(const SGVec3d& _off) const {
-    double hdg = _selected_ac->getDoubleValue("orientation/true-heading-deg");
-    double pitch = _selected_ac->getDoubleValue("orientation/pitch-deg");
-    double roll = _selected_ac->getDoubleValue("orientation/roll-deg");
-
-    // Transform that one to the horizontal local coordinate system.
-    SGQuatd hlTrans = SGQuatd::fromLonLat(_selectedpos);
-
-    // and postrotate the orientation of the AIModel wrt the horizontal
-    // local frame
-    hlTrans *= SGQuatd::fromYawPitchRollDeg(hdg, pitch, roll);
-
-    // The offset converted to the usual body fixed coordinate system
-    // rotated to the earth fiexed coordinates axis
-    SGVec3d off = hlTrans.backTransform(_off);
-
-    // Add the position offset of the AIModel to gain the earth centered position
-    SGVec3d cartPos = SGVec3d::fromGeod(_selectedpos);
-
-    return cartPos + off;
-}
-
-
-void FGAIEscort::setStationSpeed(){
-
-    double speed = 0;
-    double angle = 0;
-
-    // these are the AI rules for the manoeuvring of escorts
-
-    if (_MPControl && _tgtrange > 4 * _stn_limit){
-        SG_LOG(SG_GENERAL, SG_ALERT, "AIEscort: " << _name
-            << " re-aligning to MP pos");
-        pos = _tgtpos;
-        speed = 0;
-        angle = 0;
-    }else if ((_relbrg < -90 || _relbrg > 90) && _tgtrange > _stn_limit ){
-        angle =_relbrg;
-
-        if(_tgtrange > 4 * _stn_limit)
-            speed = 4 * -_stn_speed;
-        else
-            speed = -_stn_speed;
-
-    }else if ((_relbrg >= -90 || _relbrg <= 90) && _tgtrange > _stn_limit){
-        angle = _relbrg;
-
-        if(_tgtrange > 4 * _stn_limit)
-            speed = 4 * _stn_speed;
-        else
-            speed = _stn_speed;
-
-    } else {
-
-        if(_patrol){
-            angle = 15 * sg_random();
-            speed =  5 * sg_random();
-        } else {
-            angle = 0;
-            speed = 0;
-        }
-
-    }
-
-    double station_speed = _parent_speed + speed;
-
-    SG_CLAMP_RANGE(station_speed, 5.0, _max_speed);
-    SG_CLAMP_RANGE(angle, -_stn_angle_limit, _stn_angle_limit);
-
-    AccelTo(station_speed);
-    TurnTo(_parent_hdg + angle);
-    ClimbTo(_stn_height);
-
-}
-
-void FGAIEscort::RunEscort(double dt){
-
-    _dt_count += dt;
-
-
-
-    ///////////////////////////////////////////////////////////////////////////
-    // Check execution time (currently once every 0.05 sec or 20 fps)
-    // Add a bit of randomization to prevent the execution of all flight plans
-    // in synchrony, which can add significant periodic framerate flutter.
-    // Randomization removed to get better appearance
-    ///////////////////////////////////////////////////////////////////////////
-
-    //cout << "_start_sec " << _start_sec << " time_sec " << time_sec << endl;
-    if (_dt_count < _next_run)
-        return;
-    _next_run = _interval /*+ (0.015 * sg_random())*/;
-
-    if(_parent == ""){
-        return;
-    }
-
-    setParent();
-    setStationSpeed();
-    //getGroundElev(pos);
-
-    _dt_count = 0;
-
-}
-
-// end AIGroundvehicle
+// FGAIEscort - FGAIShip-derived class creates an AI Ground Vehicle
+// by adding a ground following utility
+//
+// Written by Vivian Meazza, started August 2009.
+// - vivian.meazza at lineone.net
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
+#include <algorithm>
+#include <string>
+#include <vector>
+
+#include <simgear/sg_inlines.h>
+#include <simgear/math/sg_geodesy.hxx>
+#include <simgear/math/sg_random.h>
+
+#include <math.h>
+#include <Main/util.hxx>
+#include <Viewer/viewer.hxx>
+
+#include <Scenery/scenery.hxx>
+
+#include "AIEscort.hxx"
+
+using std::string;
+
+FGAIEscort::FGAIEscort() :
+FGAIShip(otEscort),
+
+_relbrg (0),
+_parent_speed(0),
+_interval(0),
+_stn_truebrg(0),
+_stn_height(0),
+_stn_speed(0),
+_stn_angle_limit(0),
+_stn_limit(0),
+_max_speed(0),
+_MPControl(false),
+_patrol(false),
+_stn_deg_true(false)
+
+{
+    invisible = false;
+}
+
+FGAIEscort::~FGAIEscort() {}
+
+void FGAIEscort::readFromScenario(SGPropertyNode* scFileNode) {
+    if (!scFileNode)
+        return;
+
+    FGAIShip::readFromScenario(scFileNode);
+
+    setName(scFileNode->getStringValue("name", "Escort"));
+    setSMPath(scFileNode->getStringValue("submodel-path", ""));
+    setStnRange(scFileNode->getDoubleValue("station/range-nm", 1));
+    setStnBrg(scFileNode->getDoubleValue("station/brg-deg", 0.0));
+    setStnLimit(scFileNode->getDoubleValue("station/range-limit-nm", 0.2));
+    setStnAngleLimit(scFileNode->getDoubleValue("station/angle-limit-deg", 15.0));
+    setStnSpeed(scFileNode->getDoubleValue("station/speed-kts", 2.5));
+    setStnPatrol(scFileNode->getBoolValue("station/patrol", false));
+    setStnHtFt(scFileNode->getDoubleValue("station/height-ft", 0.0));
+    setStnDegTrue(scFileNode->getBoolValue("station/deg-true", false));
+    setParentName(scFileNode->getStringValue("station/parent", ""));
+    setMaxSpeed(scFileNode->getDoubleValue("max-speed-kts", 30.0));
+    setUpdateInterval(scFileNode->getDoubleValue("update-interval-sec", 10.0));
+    setCallSign(scFileNode->getStringValue("callsign", ""));
+
+    if(_patrol)
+        sg_srandom_time();
+
+}
+
+void FGAIEscort::bind() {
+    FGAIShip::bind();
+
+    tie("station/rel-bearing-deg",
+        SGRawValuePointer<double>(&_stn_relbrg));
+    tie("station/true-bearing-deg",
+        SGRawValuePointer<double>(&_stn_truebrg));
+    tie("station/range-nm",
+        SGRawValuePointer<double>(&_stn_range));
+    tie("station/range-limit-nm",
+        SGRawValuePointer<double>(&_stn_limit));
+    tie("station/angle-limit-deg",
+        SGRawValuePointer<double>(&_stn_angle_limit));
+    tie("station/speed-kts",
+        SGRawValuePointer<double>(&_stn_speed));
+    tie("station/height-ft",
+        SGRawValuePointer<double>(&_stn_height));
+    tie("controls/update-interval-sec",
+        SGRawValuePointer<double>(&_interval));
+    tie("controls/parent-mp-control",
+        SGRawValuePointer<bool>(&_MPControl));
+    tie("station/target-range-nm",
+        SGRawValuePointer<double>(&_tgtrange));
+    tie("station/target-brg-deg-t",
+        SGRawValuePointer<double>(&_tgtbrg));
+    tie("station/patrol",
+        SGRawValuePointer<bool>(&_patrol));
+}
+
+bool FGAIEscort::init(bool search_in_AI_path) {
+    if (!FGAIShip::init(search_in_AI_path))
+        return false;
+    reinit();
+    return true;
+}
+
+void FGAIEscort::reinit() {
+    invisible = false;
+    no_roll = false;
+
+    props->setStringValue("controls/parent-name", _parent.c_str());
+
+    if (setParentNode()){
+        setParent();
+        pos = _tgtpos;
+        speed = _parent_speed;
+        hdg = _parent_hdg;
+    }
+
+    FGAIShip::reinit();
+}
+
+void FGAIEscort::update(double dt) {
+    FGAIShip::update(dt);
+
+    RunEscort(dt);
+}
+
+void FGAIEscort::setStnRange(double r) {
+    _stn_range = r;
+}
+
+void FGAIEscort::setStnBrg(double b) {
+    _stn_brg = b;
+}
+
+void FGAIEscort::setStnLimit(double l) {
+    _stn_limit = l;
+}
+
+void FGAIEscort::setStnAngleLimit(double al) {
+    _stn_angle_limit = al;
+}
+
+void FGAIEscort::setStnSpeed(double s) {
+    _stn_speed = s;
+}
+
+void FGAIEscort::setStnHtFt(double h) {
+    _stn_height = h;
+}
+
+void FGAIEscort::setStnDegTrue(bool t) {
+    _stn_deg_true = t;
+}
+
+void FGAIEscort::setMaxSpeed(double m) {
+    _max_speed = m;
+}
+
+void FGAIEscort::setUpdateInterval(double i) {
+    _interval = i;
+}
+
+void FGAIEscort::setStnPatrol(bool p) {
+    _patrol = p;
+}
+
+bool FGAIEscort::getGroundElev(SGGeod inpos) {
+
+    double height_m ;
+
+    const simgear::BVHMaterial* mat = 0;
+    if (globals->get_scenery()->get_elevation_m(SGGeod::fromGeodM(inpos, 3000), height_m, &mat, 0)){
+        const SGMaterial* material = dynamic_cast<const SGMaterial*>(mat);
+        _ht_agl_ft = inpos.getElevationFt() - height_m * SG_METER_TO_FEET;
+
+        if (material) {
+            const std::vector<std::string>& names = material->get_names();
+
+            _solid = material->get_solid();
+
+            if (!names.empty())
+                props->setStringValue("material/name", names[0].c_str());
+            else
+                props->setStringValue("material/name", "");
+
+            //cout << "material " << names[0].c_str()
+            //    << " _elevation_m " << _elevation_m
+            //    << " solid " << _solid
+            //    << " load " << _load_resistance
+            //    << " frictionFactor " << _frictionFactor
+            //    << endl;
+
+        }
+
+        return true;
+    } else {
+        return false;
+    }
+
+}
+
+void FGAIEscort::setParent()
+{
+    double lat = _selected_ac->getDoubleValue("position/latitude-deg");
+    double lon = _selected_ac->getDoubleValue("position/longitude-deg");
+    double elevation = _selected_ac->getDoubleValue("position/altitude-ft");
+    _MPControl = _selected_ac->getBoolValue("controls/mp-control");
+
+    _selectedpos.setLatitudeDeg(lat);
+    _selectedpos.setLongitudeDeg(lon);
+    _selectedpos.setElevationFt(elevation);
+
+    _parent_speed    = _selected_ac->getDoubleValue("velocities/speed-kts");
+    _parent_hdg      = _selected_ac->getDoubleValue("orientation/true-heading-deg");
+
+    if(!_stn_deg_true){
+        _stn_truebrg = calcTrueBearingDeg(_stn_brg, _parent_hdg);
+        _stn_relbrg = _stn_brg;
+        //cout << _name <<" set rel"<<endl;
+    } else {
+        _stn_truebrg = _stn_brg;
+        _stn_relbrg = calcRelBearingDeg(_stn_brg, _parent_hdg); 
+        //cout << _name << " set true"<<endl;
+    }
+
+    double course2;
+
+    SGGeodesy::direct( _selectedpos, _stn_truebrg, _stn_range * SG_NM_TO_METER,
+        _tgtpos, course2);
+
+    _tgtpos.setElevationFt(_stn_height);
+
+    calcRangeBearing(pos.getLatitudeDeg(), pos.getLongitudeDeg(),
+        _tgtpos.getLatitudeDeg(), _tgtpos.getLongitudeDeg(), _tgtrange, _tgtbrg);
+
+    _relbrg = calcRelBearingDeg(_tgtbrg, hdg);
+
+}
+
+void FGAIEscort::calcRangeBearing(double lat, double lon, double lat2, double lon2,
+                                  double &range, double &bearing) const
+{
+    // calculate the bearing and range of the second pos from the first
+    double az2, distance;
+    geo_inverse_wgs_84(lat, lon, lat2, lon2, &bearing, &az2, &distance);
+    range = distance * SG_METER_TO_NM;
+}
+
+double FGAIEscort::calcTrueBearingDeg(double bearing, double heading)
+{
+    double angle = bearing + heading;
+    SG_NORMALIZE_RANGE(angle, 0.0, 360.0);
+    return angle;
+}
+
+SGVec3d FGAIEscort::getCartHitchPosAt(const SGVec3d& _off) const {
+    double hdg = _selected_ac->getDoubleValue("orientation/true-heading-deg");
+    double pitch = _selected_ac->getDoubleValue("orientation/pitch-deg");
+    double roll = _selected_ac->getDoubleValue("orientation/roll-deg");
+
+    // Transform that one to the horizontal local coordinate system.
+    SGQuatd hlTrans = SGQuatd::fromLonLat(_selectedpos);
+
+    // and postrotate the orientation of the AIModel wrt the horizontal
+    // local frame
+    hlTrans *= SGQuatd::fromYawPitchRollDeg(hdg, pitch, roll);
+
+    // The offset converted to the usual body fixed coordinate system
+    // rotated to the earth fiexed coordinates axis
+    SGVec3d off = hlTrans.backTransform(_off);
+
+    // Add the position offset of the AIModel to gain the earth centered position
+    SGVec3d cartPos = SGVec3d::fromGeod(_selectedpos);
+
+    return cartPos + off;
+}
+
+
+void FGAIEscort::setStationSpeed(){
+
+    double speed = 0;
+    double angle = 0;
+
+    // these are the AI rules for the manoeuvring of escorts
+
+    if (_MPControl && _tgtrange > 4 * _stn_limit){
+        SG_LOG(SG_AI, SG_ALERT, "AIEscort: " << _name
+            << " re-aligning to MP pos");
+        pos = _tgtpos;
+        speed = 0;
+        angle = 0;
+    }else if ((_relbrg < -90 || _relbrg > 90) && _tgtrange > _stn_limit ){
+        angle =_relbrg;
+
+        if(_tgtrange > 4 * _stn_limit)
+            speed = 4 * -_stn_speed;
+        else
+            speed = -_stn_speed;
+
+    }else if ((_relbrg >= -90 || _relbrg <= 90) && _tgtrange > _stn_limit){
+        angle = _relbrg;
+
+        if(_tgtrange > 4 * _stn_limit)
+            speed = 4 * _stn_speed;
+        else
+            speed = _stn_speed;
+
+    } else {
+
+        if(_patrol){
+            angle = 15 * sg_random();
+            speed =  5 * sg_random();
+        } else {
+            angle = 0;
+            speed = 0;
+        }
+
+    }
+
+    double station_speed = _parent_speed + speed;
+
+    SG_CLAMP_RANGE(station_speed, 5.0, _max_speed);
+    SG_CLAMP_RANGE(angle, -_stn_angle_limit, _stn_angle_limit);
+
+    AccelTo(station_speed);
+    TurnTo(_parent_hdg + angle);
+    ClimbTo(_stn_height);
+
+}
+
+void FGAIEscort::RunEscort(double dt){
+
+    _dt_count += dt;
+
+
+
+    ///////////////////////////////////////////////////////////////////////////
+    // Check execution time (currently once every 0.05 sec or 20 fps)
+    // Add a bit of randomization to prevent the execution of all flight plans
+    // in synchrony, which can add significant periodic framerate flutter.
+    // Randomization removed to get better appearance
+    ///////////////////////////////////////////////////////////////////////////
+
+    //cout << "_start_sec " << _start_sec << " time_sec " << time_sec << endl;
+    if (_dt_count < _next_run)
+        return;
+    _next_run = _interval /*+ (0.015 * sg_random())*/;
+
+    if(_parent == ""){
+        return;
+    }
+
+    setParent();
+    setStationSpeed();
+
+    _dt_count = 0;
+
+}
+
+// end AIEscort