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., 675 Mass Ave, Cambridge, MA 02139, 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
56 _refID( _newAIModelID() )
59 tgt_heading = 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;
73 FGAIBase::~FGAIBase() {
74 // Unregister that one at the scenery manager
75 if (globals->get_scenery()) {
76 globals->get_scenery()->unregister_placement_transform(aip.getTransform());
77 globals->get_scenery()->get_scene_graph()->removeKid(aip.getSceneGraph());
80 SGPropertyNode *root = globals->get_props()->getNode("ai/models", true);
81 root->removeChild(_type_str.c_str(), index);
86 void FGAIBase::update(double dt) {
87 if (_otype == otStatic) return;
88 if (_otype == otBallistic) CalculateMach();
90 ft_per_deg_lat = 366468.96 - 3717.12 * cos(pos.lat()*SGD_DEGREES_TO_RADIANS);
91 ft_per_deg_lon = 365228.16 * cos(pos.lat()*SGD_DEGREES_TO_RADIANS);
94 void FGAIBase::Transform() {
96 aip.setPosition(pos.lon(), pos.lat(), pos.elev() * SG_METER_TO_FEET);
98 aip.setOrientation(0.0, pitch, hdg);
100 aip.setOrientation(roll, pitch, hdg);
107 bool FGAIBase::init() {
109 SGPropertyNode *root = globals->get_props()->getNode("ai/models", true);
111 index = manager->getNum(_otype) - 1;
112 props = root->getNode(_type_str.c_str(), index, true);
114 if (model_path != "") {
116 model = load3DModel( globals->get_fg_root(),
117 SGPath(model_path).c_str(),
119 globals->get_sim_time_sec() );
120 } catch (const sg_exception &e) {
126 aip.setVisible(true);
128 globals->get_scenery()->get_scene_graph()->addKid(aip.getSceneGraph());
129 // Register that one at the scenery manager
130 globals->get_scenery()->register_placement_transform(aip.getTransform());
132 if (model_path != "") {
133 SG_LOG(SG_INPUT, SG_WARN, "AIBase: Could not load model " << model_path);
143 ssgBranch * FGAIBase::load3DModel(const string& fg_root,
145 SGPropertyNode *prop_root,
148 // some more code here to check whether a model with this name has already been loaded
149 // if not load it, otherwise, get the memory pointer and do something like
150 // SetModel as in ATC/AIEntity.cxx
151 model = manager->getModel(path);
154 model = sgLoad3DModel(fg_root,
158 manager->setModel(path, model);
164 bool FGAIBase::isa( object_type otype ) {
165 if ( otype == _otype ) { return true; }
166 else { return false; }
170 void FGAIBase::bind() {
171 props->tie("id", SGRawValueMethods<FGAIBase,int>(*this,
173 props->tie("velocities/true-airspeed-kt", SGRawValuePointer<double>(&speed));
174 props->tie("velocities/vertical-speed-fps",
175 SGRawValueMethods<FGAIBase,double>(*this,
176 &FGAIBase::_getVS_fps,
177 &FGAIBase::_setVS_fps));
179 props->tie("position/altitude-ft",
180 SGRawValueMethods<FGAIBase,double>(*this,
181 &FGAIBase::_getAltitude,
182 &FGAIBase::_setAltitude));
183 props->tie("position/latitude-deg",
184 SGRawValueMethods<FGAIBase,double>(*this,
185 &FGAIBase::_getLatitude,
186 &FGAIBase::_setLatitude));
187 props->tie("position/longitude-deg",
188 SGRawValueMethods<FGAIBase,double>(*this,
189 &FGAIBase::_getLongitude,
190 &FGAIBase::_setLongitude));
192 props->tie("orientation/pitch-deg", SGRawValuePointer<double>(&pitch));
193 props->tie("orientation/roll-deg", SGRawValuePointer<double>(&roll));
194 props->tie("orientation/true-heading-deg", SGRawValuePointer<double>(&hdg));
196 props->tie("radar/in-range", SGRawValuePointer<bool>(&in_range));
197 props->tie("radar/bearing-deg", SGRawValuePointer<double>(&bearing));
198 props->tie("radar/elevation-deg", SGRawValuePointer<double>(&elevation));
199 props->tie("radar/range-nm", SGRawValuePointer<double>(&range));
200 props->tie("radar/h-offset", SGRawValuePointer<double>(&horiz_offset));
201 props->tie("radar/v-offset", SGRawValuePointer<double>(&vert_offset));
202 props->tie("radar/x-shift", SGRawValuePointer<double>(&x_shift));
203 props->tie("radar/y-shift", SGRawValuePointer<double>(&y_shift));
204 props->tie("radar/rotation", SGRawValuePointer<double>(&rotation));
206 props->tie("controls/lighting/nav-lights",
207 SGRawValueFunctions<bool>(_isNight));
208 props->setBoolValue("controls/lighting/beacon", true);
209 props->setBoolValue("controls/lighting/strobe", true);
210 props->setBoolValue("controls/glide-path", true);
213 void FGAIBase::unbind() {
215 props->untie("velocities/true-airspeed-kt");
216 props->untie("velocities/vertical-speed-fps");
218 props->untie("position/altitude-ft");
219 props->untie("position/latitude-deg");
220 props->untie("position/longitude-deg");
222 props->untie("orientation/pitch-deg");
223 props->untie("orientation/roll-deg");
224 props->untie("orientation/true-heading-deg");
226 props->untie("radar/in-range");
227 props->untie("radar/bearing-deg");
228 props->untie("radar/elevation-deg");
229 props->untie("radar/range-nm");
230 props->untie("radar/h-offset");
231 props->untie("radar/v-offset");
232 props->untie("radar/x-shift");
233 props->untie("radar/y-shift");
234 props->untie("radar/rotation");
236 props->untie("controls/lighting/nav-lights");
239 double FGAIBase::UpdateRadar(FGAIManager* manager)
241 double radar_range_ft2 = fgGetDouble("/instrumentation/radar/range");
242 radar_range_ft2 *= SG_NM_TO_METER * SG_METER_TO_FEET * 1.1; // + 10%
243 radar_range_ft2 *= radar_range_ft2;
245 double user_latitude = manager->get_user_latitude();
246 double user_longitude = manager->get_user_longitude();
247 double lat_range = fabs(pos.lat() - user_latitude) * ft_per_deg_lat;
248 double lon_range = fabs(pos.lon() - user_longitude) * ft_per_deg_lon;
249 double range_ft2 = lat_range*lat_range + lon_range*lon_range;
252 // Test whether the target is within radar range.
254 in_range = (range_ft2 && (range_ft2 <= radar_range_ft2));
257 props->setBoolValue("radar/in-range", true);
259 // copy values from the AIManager
260 double user_altitude = manager->get_user_altitude();
261 double user_heading = manager->get_user_heading();
262 double user_pitch = manager->get_user_pitch();
263 double user_yaw = manager->get_user_yaw();
264 double user_speed = manager->get_user_speed();
266 // calculate range to target in feet and nautical miles
267 double range_ft = sqrt( range_ft2 );
268 range = range_ft / 6076.11549;
270 // calculate bearing to target
271 if (pos.lat() >= user_latitude) {
272 bearing = atan2(lat_range, lon_range) * SG_RADIANS_TO_DEGREES;
273 if (pos.lon() >= user_longitude) {
274 bearing = 90.0 - bearing;
276 bearing = 270.0 + bearing;
279 bearing = atan2(lon_range, lat_range) * SG_RADIANS_TO_DEGREES;
280 if (pos.lon() >= user_longitude) {
281 bearing = 180.0 - bearing;
283 bearing = 180.0 + bearing;
287 // calculate look left/right to target, without yaw correction
288 horiz_offset = bearing - user_heading;
289 if (horiz_offset > 180.0) horiz_offset -= 360.0;
290 if (horiz_offset < -180.0) horiz_offset += 360.0;
292 // calculate elevation to target
293 elevation = atan2( altitude * SG_METER_TO_FEET - user_altitude, range_ft )
294 * SG_RADIANS_TO_DEGREES;
296 // calculate look up/down to target
297 vert_offset = elevation + user_pitch;
299 /* this calculation needs to be fixed, but it isn't important anyway
300 // calculate range rate
301 double recip_bearing = bearing + 180.0;
302 if (recip_bearing > 360.0) recip_bearing -= 360.0;
303 double my_horiz_offset = recip_bearing - hdg;
304 if (my_horiz_offset > 180.0) my_horiz_offset -= 360.0;
305 if (my_horiz_offset < -180.0) my_horiz_offset += 360.0;
306 rdot = (-user_speed * cos( horiz_offset * SG_DEGREES_TO_RADIANS ))
307 +(-speed * 1.686 * cos( my_horiz_offset * SG_DEGREES_TO_RADIANS ));
310 // now correct look left/right for yaw
311 horiz_offset += user_yaw;
313 // calculate values for radar display
314 y_shift = range * cos( horiz_offset * SG_DEGREES_TO_RADIANS);
315 x_shift = range * sin( horiz_offset * SG_DEGREES_TO_RADIANS);
316 rotation = hdg - user_heading;
317 if (rotation < 0.0) rotation += 360.0;
325 FGAIBase::getCartPosAt(const Point3D& off) const
327 // The offset converted to the usual body fixed coordinate system.
329 sgdSetVec3(sgdOff, -off.x(), off.z(), -off.y());
331 // Transform that one to the horizontal local coordinate system.
333 sgdMakeRotMat4(hlTrans, hdg, pitch, roll);
334 sgdXformPnt3(sgdOff, hlTrans);
336 // Now transform to the wgs84 earth centeres system.
337 Point3D pos2(pos.lon()* SGD_DEGREES_TO_RADIANS,
338 pos.lat() * SGD_DEGREES_TO_RADIANS,
340 Point3D cartPos3D = sgGeodToCart(pos2);
342 sgdMakeCoordMat4(ecTrans, cartPos3D.x(), cartPos3D.y(), cartPos3D.z(),
343 pos.lon(), 0, - 90 - pos.lat());
344 sgdXformPnt3(sgdOff, ecTrans);
346 return Point3D(sgdOff[0], sgdOff[1], sgdOff[2]);
350 FGAIBase::getGeocPosAt(const Point3D& off) const
352 return sgCartToGeod(getCartPosAt(off));
356 * getters and Setters
358 void FGAIBase::_setLongitude( double longitude ) {
359 pos.setlon(longitude);
361 void FGAIBase::_setLatitude ( double latitude ) {
362 pos.setlat(latitude);
365 double FGAIBase::_getLongitude() const {
368 double FGAIBase::_getLatitude () const {
371 double FGAIBase::_getRdot() const {
374 double FGAIBase::_getVS_fps() const {
377 void FGAIBase::_setVS_fps( double _vs ) {
381 double FGAIBase::_getAltitude() const {
384 void FGAIBase::_setAltitude( double _alt ) {
388 bool FGAIBase::_isNight() {
389 return (fgGetFloat("/sim/time/sun-angle-rad") > 1.57);
392 int FGAIBase::getID() const {
396 void FGAIBase::CalculateMach() {
397 // Calculate rho at altitude, using standard atmosphere
398 // For the temperature T and the pressure p,
400 if (altitude < 36152) { // curve fits for the troposphere
401 T = 59 - 0.00356 * altitude;
402 p = 2116 * pow( ((T + 459.7) / 518.6) , 5.256);
404 } else if ( 36152 < altitude && altitude < 82345 ) { // lower stratosphere
406 p = 473.1 * pow( e , 1.73 - (0.000048 * altitude) );
408 } else { // upper stratosphere
409 T = -205.05 + (0.00164 * altitude);
410 p = 51.97 * pow( ((T + 459.7) / 389.98) , -11.388);
413 rho = p / (1718 * (T + 459.7));
415 // calculate the speed of sound at altitude
416 // a = sqrt ( g * R * (T + 459.7))
418 // a = speed of sound [ft/s]
419 // g = specific heat ratio, which is usually equal to 1.4
420 // R = specific gas constant, which equals 1716 ft-lb/slug/°R
422 a = sqrt ( 1.4 * 1716 * (T + 459.7));
424 // calculate Mach number
428 // cout << "Speed(ft/s) "<< speed <<" Altitude(ft) "<< altitude << " Mach " << Mach;
431 int FGAIBase::_newAIModelID() {
433 if (!++id) id++; // id = 0 is not allowed.