1 // FGAIBase - abstract base class for AI objects
2 // Written by David Culp, started Nov 2003, based on
3 // David Luff's FGAIEntity class.
4 // - davidculp2@comcast.net
6 // This program is free software; you can redistribute it and/or
7 // modify it under the terms of the GNU General Public License as
8 // published by the Free Software Foundation; either version 2 of the
9 // License, or (at your option) any later version.
11 // This program is distributed in the hope that it will be useful, but
12 // WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 // General Public License for more details.
16 // You should have received a copy of the GNU General Public License
17 // along with this program; if not, write to the Free Software
18 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
25 #include <simgear/compiler.h>
32 #include <simgear/math/point3d.hxx>
33 #include <simgear/math/sg_geodesy.hxx>
34 #include <simgear/misc/sg_path.hxx>
35 #include <simgear/scene/model/location.hxx>
36 #include <simgear/scene/model/model.hxx>
37 #include <simgear/debug/logstream.hxx>
38 #include <simgear/props/props.hxx>
40 #include <Main/globals.hxx>
41 #include <Scenery/scenery.hxx>
45 #include "AIManager.hxx"
48 const double FGAIBase::e = 2.71828183;
49 const double FGAIBase::lbs_to_slugs = 0.031080950172; //conversion factor
52 FGAIBase::FGAIBase(object_type ot)
56 _refID( _newAIModelID() ),
59 tgt_heading = hdg = tgt_altitude = tgt_speed = 0.0;
60 tgt_roll = roll = tgt_pitch = tgt_yaw = tgt_vs = vs = pitch = 0.0;
61 bearing = elevation = range = rdot = 0.0;
62 x_shift = y_shift = rotation = 0.0;
70 FGAIBase::~FGAIBase() {
71 // Unregister that one at the scenery manager
72 if (globals->get_scenery()) {
73 globals->get_scenery()->unregister_placement_transform(aip.getTransform());
74 globals->get_scenery()->get_scene_graph()->removeKid(aip.getSceneGraph());
77 SGPropertyNode* parent = props->getParent();
79 parent->removeChild(props->getName(), props->getIndex(), false);
86 void FGAIBase::readFromScenario(SGPropertyNode* scFileNode)
91 setPath(scFileNode->getStringValue("model", "Models/Geometry/glider.ac"));
93 setHeading(scFileNode->getDoubleValue("heading", 0.0));
94 setSpeed(scFileNode->getDoubleValue("speed", 0.0));
95 setAltitude(scFileNode->getDoubleValue("altitude", 0.0));
96 setLongitude(scFileNode->getDoubleValue("longitude", 0.0));
97 setLatitude(scFileNode->getDoubleValue("latitude", 0.0));
98 setBank(scFileNode->getDoubleValue("roll", 0.0));
101 void FGAIBase::update(double dt) {
102 if (_otype == otStatic) return;
103 if (_otype == otBallistic) CalculateMach();
105 ft_per_deg_lat = 366468.96 - 3717.12 * cos(pos.lat()*SGD_DEGREES_TO_RADIANS);
106 ft_per_deg_lon = 365228.16 * cos(pos.lat()*SGD_DEGREES_TO_RADIANS);
109 void FGAIBase::Transform() {
111 aip.setPosition(pos.lon(), pos.lat(), pos.elev() * SG_METER_TO_FEET);
113 aip.setOrientation(0.0, pitch, hdg);
115 aip.setOrientation(roll, pitch, hdg);
122 bool FGAIBase::init() {
124 if (!model_path.empty()) {
126 model = load3DModel( globals->get_fg_root(), model_path, props,
127 globals->get_sim_time_sec() );
128 } catch (const sg_exception &e) {
134 aip.setVisible(true);
136 globals->get_scenery()->get_scene_graph()->addKid(aip.getSceneGraph());
137 // Register that one at the scenery manager
138 globals->get_scenery()->register_placement_transform(aip.getTransform());
140 if (!model_path.empty()) {
141 SG_LOG(SG_INPUT, SG_WARN, "AIBase: Could not load model " << model_path);
151 ssgBranch * FGAIBase::load3DModel(const string& fg_root,
153 SGPropertyNode *prop_root,
156 // some more code here to check whether a model with this name has already been loaded
157 // if not load it, otherwise, get the memory pointer and do something like
158 // SetModel as in ATC/AIEntity.cxx
159 model = manager->getModel(path);
162 model = sgLoad3DModel(fg_root,
166 manager->setModel(path, model);
172 bool FGAIBase::isa( object_type otype ) {
173 if ( otype == _otype ) { return true; }
174 else { return false; }
178 void FGAIBase::bind() {
179 props->tie("id", SGRawValueMethods<FGAIBase,int>(*this,
181 props->tie("velocities/true-airspeed-kt", SGRawValuePointer<double>(&speed));
182 props->tie("velocities/vertical-speed-fps",
183 SGRawValueMethods<FGAIBase,double>(*this,
184 &FGAIBase::_getVS_fps,
185 &FGAIBase::_setVS_fps));
187 props->tie("position/altitude-ft",
188 SGRawValueMethods<FGAIBase,double>(*this,
189 &FGAIBase::_getAltitude,
190 &FGAIBase::_setAltitude));
191 props->tie("position/latitude-deg",
192 SGRawValueMethods<FGAIBase,double>(*this,
193 &FGAIBase::_getLatitude,
194 &FGAIBase::_setLatitude));
195 props->tie("position/longitude-deg",
196 SGRawValueMethods<FGAIBase,double>(*this,
197 &FGAIBase::_getLongitude,
198 &FGAIBase::_setLongitude));
200 props->tie("orientation/pitch-deg", SGRawValuePointer<double>(&pitch));
201 props->tie("orientation/roll-deg", SGRawValuePointer<double>(&roll));
202 props->tie("orientation/true-heading-deg", SGRawValuePointer<double>(&hdg));
204 props->tie("radar/in-range", SGRawValuePointer<bool>(&in_range));
205 props->tie("radar/bearing-deg", SGRawValuePointer<double>(&bearing));
206 props->tie("radar/elevation-deg", SGRawValuePointer<double>(&elevation));
207 props->tie("radar/range-nm", SGRawValuePointer<double>(&range));
208 props->tie("radar/h-offset", SGRawValuePointer<double>(&horiz_offset));
209 props->tie("radar/v-offset", SGRawValuePointer<double>(&vert_offset));
210 props->tie("radar/x-shift", SGRawValuePointer<double>(&x_shift));
211 props->tie("radar/y-shift", SGRawValuePointer<double>(&y_shift));
212 props->tie("radar/rotation", SGRawValuePointer<double>(&rotation));
213 props->tie("radar/ht-diff-ft", SGRawValuePointer<double>(&ht_diff));
215 props->tie("controls/lighting/nav-lights",
216 SGRawValueFunctions<bool>(_isNight));
217 props->setBoolValue("controls/lighting/beacon", true);
218 props->setBoolValue("controls/lighting/strobe", true);
219 props->setBoolValue("controls/glide-path", true);
222 void FGAIBase::unbind() {
224 props->untie("velocities/true-airspeed-kt");
225 props->untie("velocities/vertical-speed-fps");
227 props->untie("position/altitude-ft");
228 props->untie("position/latitude-deg");
229 props->untie("position/longitude-deg");
231 props->untie("orientation/pitch-deg");
232 props->untie("orientation/roll-deg");
233 props->untie("orientation/true-heading-deg");
235 props->untie("radar/in-range");
236 props->untie("radar/bearing-deg");
237 props->untie("radar/elevation-deg");
238 props->untie("radar/range-nm");
239 props->untie("radar/h-offset");
240 props->untie("radar/v-offset");
241 props->untie("radar/x-shift");
242 props->untie("radar/y-shift");
243 props->untie("radar/rotation");
244 props->untie("radar/ht-diff-ft");
246 props->untie("controls/lighting/nav-lights");
249 double FGAIBase::UpdateRadar(FGAIManager* manager)
251 double radar_range_ft2 = fgGetDouble("/instrumentation/radar/range");
252 radar_range_ft2 *= SG_NM_TO_METER * SG_METER_TO_FEET * 1.1; // + 10%
253 radar_range_ft2 *= radar_range_ft2;
255 double user_latitude = manager->get_user_latitude();
256 double user_longitude = manager->get_user_longitude();
257 double lat_range = fabs(pos.lat() - user_latitude) * ft_per_deg_lat;
258 double lon_range = fabs(pos.lon() - user_longitude) * ft_per_deg_lon;
259 double range_ft2 = lat_range*lat_range + lon_range*lon_range;
262 // Test whether the target is within radar range.
264 in_range = (range_ft2 && (range_ft2 <= radar_range_ft2));
267 props->setBoolValue("radar/in-range", true);
269 // copy values from the AIManager
270 double user_altitude = manager->get_user_altitude();
271 double user_heading = manager->get_user_heading();
272 double user_pitch = manager->get_user_pitch();
273 double user_yaw = manager->get_user_yaw();
274 double user_speed = manager->get_user_speed();
276 // calculate range to target in feet and nautical miles
277 double range_ft = sqrt( range_ft2 );
278 range = range_ft / 6076.11549;
280 // calculate bearing to target
281 if (pos.lat() >= user_latitude) {
282 bearing = atan2(lat_range, lon_range) * SG_RADIANS_TO_DEGREES;
283 if (pos.lon() >= user_longitude) {
284 bearing = 90.0 - bearing;
286 bearing = 270.0 + bearing;
289 bearing = atan2(lon_range, lat_range) * SG_RADIANS_TO_DEGREES;
290 if (pos.lon() >= user_longitude) {
291 bearing = 180.0 - bearing;
293 bearing = 180.0 + bearing;
297 // calculate look left/right to target, without yaw correction
298 horiz_offset = bearing - user_heading;
299 if (horiz_offset > 180.0) horiz_offset -= 360.0;
300 if (horiz_offset < -180.0) horiz_offset += 360.0;
302 // calculate elevation to target
303 elevation = atan2( altitude - user_altitude, range_ft ) * SG_RADIANS_TO_DEGREES;
305 // calculate look up/down to target
306 vert_offset = elevation - user_pitch;
308 /* this calculation needs to be fixed, but it isn't important anyway
309 // calculate range rate
310 double recip_bearing = bearing + 180.0;
311 if (recip_bearing > 360.0) recip_bearing -= 360.0;
312 double my_horiz_offset = recip_bearing - hdg;
313 if (my_horiz_offset > 180.0) my_horiz_offset -= 360.0;
314 if (my_horiz_offset < -180.0) my_horiz_offset += 360.0;
315 rdot = (-user_speed * cos( horiz_offset * SG_DEGREES_TO_RADIANS ))
316 +(-speed * 1.686 * cos( my_horiz_offset * SG_DEGREES_TO_RADIANS ));
319 // now correct look left/right for yaw
320 horiz_offset += user_yaw;
322 // calculate values for radar display
323 y_shift = range * cos( horiz_offset * SG_DEGREES_TO_RADIANS);
324 x_shift = range * sin( horiz_offset * SG_DEGREES_TO_RADIANS);
325 rotation = hdg - user_heading;
326 if (rotation < 0.0) rotation += 360.0;
327 ht_diff = altitude - user_altitude;
335 FGAIBase::getCartPosAt(const SGVec3d& _off) const
337 // Transform that one to the horizontal local coordinate system.
338 SGQuatd hlTrans = SGQuatd::fromLonLatDeg(pos.lon(), pos.lat());
339 // and postrotate the orientation of the AIModel wrt the horizontal
341 hlTrans *= SGQuatd::fromYawPitchRollDeg(hdg, pitch, roll);
343 // The offset converted to the usual body fixed coordinate system
344 // rotated to the earth fiexed coordinates axis
345 SGVec3d off = hlTrans.backTransform(_off);
347 // Add the position offset of the AIModel to gain the earth centered position
348 SGVec3d cartPos = SGGeod::fromDegFt(pos.lon(), pos.lat(), pos.elev());
350 return cartPos + off;
354 * getters and Setters
356 void FGAIBase::_setLongitude( double longitude ) {
357 pos.setlon(longitude);
359 void FGAIBase::_setLatitude ( double latitude ) {
360 pos.setlat(latitude);
363 double FGAIBase::_getLongitude() const {
366 double FGAIBase::_getLatitude () const {
369 double FGAIBase::_getRdot() const {
372 double FGAIBase::_getVS_fps() const {
375 void FGAIBase::_setVS_fps( double _vs ) {
379 double FGAIBase::_getAltitude() const {
382 void FGAIBase::_setAltitude( double _alt ) {
386 bool FGAIBase::_isNight() {
387 return (fgGetFloat("/sim/time/sun-angle-rad") > 1.57);
390 int FGAIBase::getID() const {
394 void FGAIBase::CalculateMach() {
395 // Calculate rho at altitude, using standard atmosphere
396 // For the temperature T and the pressure p,
398 if (altitude < 36152) { // curve fits for the troposphere
399 T = 59 - 0.00356 * altitude;
400 p = 2116 * pow( ((T + 459.7) / 518.6) , 5.256);
402 } else if ( 36152 < altitude && altitude < 82345 ) { // lower stratosphere
404 p = 473.1 * pow( e , 1.73 - (0.000048 * altitude) );
406 } else { // upper stratosphere
407 T = -205.05 + (0.00164 * altitude);
408 p = 51.97 * pow( ((T + 459.7) / 389.98) , -11.388);
411 rho = p / (1718 * (T + 459.7));
413 // calculate the speed of sound at altitude
414 // a = sqrt ( g * R * (T + 459.7))
416 // a = speed of sound [ft/s]
417 // g = specific heat ratio, which is usually equal to 1.4
418 // R = specific gas constant, which equals 1716 ft-lb/slug/°R
420 a = sqrt ( 1.4 * 1716 * (T + 459.7));
422 // calculate Mach number
426 // cout << "Speed(ft/s) "<< speed <<" Altitude(ft) "<< altitude << " Mach " << Mach;
429 int FGAIBase::_newAIModelID() {
431 if (!++id) id++; // id = 0 is not allowed.