1 // FGAIBallistic - FGAIBase-derived class creates a ballistic object
3 // Written by David Culp, started November 2003.
4 // - davidculp2@comcast.net
6 // With major additions by Mathias Froehlich & Vivian Meazza 2004-2007
8 // This program is free software; you can redistribute it and/or
9 // modify it under the terms of the GNU General Public License as
10 // published by the Free Software Foundation; either version 2 of the
11 // License, or (at your option) any later version.
13 // This program is distributed in the hope that it will be useful, but
14 // WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 // General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
26 #include <simgear/math/point3d.hxx>
27 #include <simgear/math/sg_random.h>
28 #include <simgear/scene/material/mat.hxx>
29 #include <simgear/math/sg_geodesy.hxx>
31 #include <Scenery/scenery.hxx>
33 #include "AIBallistic.hxx"
35 const double FGAIBallistic::slugs_to_kgs = 14.5939029372;
37 FGAIBallistic::FGAIBallistic() :
38 FGAIBase(otBallistic),
39 _aero_stabilised(false),
48 _report_collision(false),
49 _report_impact(false),
50 _impact_report_node(fgGetNode("/ai/models/model-impact", true)),
56 FGAIBallistic::~FGAIBallistic() {
59 void FGAIBallistic::readFromScenario(SGPropertyNode* scFileNode) {
63 FGAIBase::readFromScenario(scFileNode);
65 setAzimuth(scFileNode->getDoubleValue("azimuth", 0.0));
66 setElevation(scFileNode->getDoubleValue("elevation", 0.0));
67 setDragArea(scFileNode->getDoubleValue("eda", 0.007));
68 setLife(scFileNode->getDoubleValue("life", 900.0));
69 setBuoyancy(scFileNode->getDoubleValue("buoyancy", 0));
70 setWind_from_east(scFileNode->getDoubleValue("wind_from_east", 0));
71 setWind_from_north(scFileNode->getDoubleValue("wind_from_north", 0));
72 setWind(scFileNode->getBoolValue("wind", false));
73 setRoll(scFileNode->getDoubleValue("roll", 0.0));
74 setCd(scFileNode->getDoubleValue("cd", 0.029));
75 setMass(scFileNode->getDoubleValue("mass", 0.007));
76 setStabilisation(scFileNode->getBoolValue("aero_stabilized", false));
77 setNoRoll(scFileNode->getBoolValue("no-roll", false));
78 setRandom(scFileNode->getBoolValue("random", false));
79 setImpact(scFileNode->getBoolValue("impact", false));
80 setImpactReportNode(scFileNode->getStringValue("impact-reports"));
81 setName(scFileNode->getStringValue("name", "Bomb"));
82 setFuseRange(scFileNode->getDoubleValue("fuse-range", 0.0));
83 setSMPath(scFileNode->getStringValue("submodel-path", ""));
84 setSubID(scFileNode->getIntValue("SubID", 0));
87 bool FGAIBallistic::init(bool search_in_AI_path) {
88 FGAIBase::init(search_in_AI_path);
90 props->setStringValue("material/name", _mat_name.c_str());
91 props->setStringValue("name", _name.c_str());
92 props->setStringValue("submodels/path", _submodel.c_str());
94 // start with high value so that animations don't trigger yet
95 _ht_agl_ft = 10000000;
104 void FGAIBallistic::bind() {
106 props->tie("sim/time/elapsed-sec",
107 SGRawValueMethods<FGAIBallistic,double>(*this,
108 &FGAIBallistic::_getTime));
109 props->tie("material/load-resistance",
110 SGRawValuePointer<double>(&_load_resistance));
111 props->tie("material/solid",
112 SGRawValuePointer<bool>(&_solid));
113 props->tie("altitude-agl-ft",
114 SGRawValuePointer<double>(&_ht_agl_ft));
116 SGRawValuePointer<int>(&_subID));
119 void FGAIBallistic::unbind() {
120 // FGAIBase::unbind();
121 props->untie("sim/time/elapsed-sec");
122 props->untie("material/load-resistance");
123 props->untie("material/solid");
124 props->untie("altitude-agl-ft");
125 props->untie("sub-id");
128 void FGAIBallistic::update(double dt) {
129 FGAIBase::update(dt);
134 void FGAIBallistic::setAzimuth(double az) {
138 void FGAIBallistic::setElevation(double el) {
139 pitch = _elevation = el;
142 void FGAIBallistic::setRoll(double rl) {
146 void FGAIBallistic::setStabilisation(bool val) {
147 _aero_stabilised = val;
150 void FGAIBallistic::setNoRoll(bool nr) {
154 void FGAIBallistic::setDragArea(double a) {
158 void FGAIBallistic::setLife(double seconds) {
162 void FGAIBallistic::setBuoyancy(double fpss) {
166 void FGAIBallistic::setWind_from_east(double fps) {
167 _wind_from_east = fps;
170 void FGAIBallistic::setWind_from_north(double fps) {
171 _wind_from_north = fps;
174 void FGAIBallistic::setWind(bool val) {
178 void FGAIBallistic::setCd(double c) {
182 void FGAIBallistic::setMass(double m) {
186 void FGAIBallistic::setRandom(bool r) {
190 void FGAIBallistic::setImpact(bool i) {
194 void FGAIBallistic::setCollision(bool c) {
195 _report_collision = c;
198 void FGAIBallistic::setImpactReportNode(const string& path) {
200 _impact_report_node = fgGetNode(path.c_str(), true);
203 void FGAIBallistic::setName(const string& n) {
207 void FGAIBallistic::setSMPath(const string& s) {
211 void FGAIBallistic::setFuseRange(double f) {
215 void FGAIBallistic::setSubID(int i) {
217 //cout << "sub id " << _subID << " name " << _name << endl;
220 void FGAIBallistic::setSubmodel(const string& s) {
224 void FGAIBallistic::Run(double dt) {
226 //cout << "life timer" <<_name <<" " << _life_timer << dt << endl;
227 if (_life_timer > life)
230 double speed_north_deg_sec;
231 double speed_east_deg_sec;
232 double wind_speed_from_north_deg_sec;
233 double wind_speed_from_east_deg_sec;
234 double Cdm; // Cd adjusted by Mach Number
237 //randomise Cd by +- 5%
239 _Cd = _Cd * 0.95 + (0.05 * sg_random());
241 // Adjust Cd by Mach number. The equations are based on curves
242 // for a conventional shell/bullet (no boat-tail).
244 Cdm = 0.0125 * Mach + _Cd;
245 else if (Mach < 1.2 )
246 Cdm = 0.3742 * pow(Mach, 2) - 0.252 * Mach + 0.0021 + _Cd;
248 Cdm = 0.2965 * pow(Mach, -1.1506) + _Cd;
250 //cout << " Mach , " << Mach << " , Cdm , " << Cdm << " ballistic speed kts //"<< speed << endl;
252 // drag = Cd * 0.5 * rho * speed * speed * drag_area;
253 // rho is adjusted for altitude in void FGAIBase::update,
254 // using Standard Atmosphere (sealevel temperature 15C)
255 // acceleration = drag/mass;
256 // adjust speed by drag
257 speed -= (Cdm * 0.5 * rho * speed * speed * _drag_area/_mass) * dt;
259 // don't let speed become negative
263 double speed_fps = speed * SG_KT_TO_FPS;
265 // calculate vertical and horizontal speed components
269 vs = sin( pitch * SG_DEGREES_TO_RADIANS ) * speed_fps;
270 hs = cos( pitch * SG_DEGREES_TO_RADIANS ) * speed_fps;
273 // convert horizontal speed (fps) to degrees per second
274 speed_north_deg_sec = cos(hdg / SG_RADIANS_TO_DEGREES) * hs / ft_per_deg_lat;
275 speed_east_deg_sec = sin(hdg / SG_RADIANS_TO_DEGREES) * hs / ft_per_deg_lon;
277 // if wind not required, set to zero
279 _wind_from_north = 0;
283 // convert wind speed (fps) to degrees per second
284 wind_speed_from_north_deg_sec = _wind_from_north / ft_per_deg_lat;
285 wind_speed_from_east_deg_sec = _wind_from_east / ft_per_deg_lon;
288 pos.setLatitudeDeg( pos.getLatitudeDeg()
289 + (speed_north_deg_sec - wind_speed_from_north_deg_sec) * dt );
290 pos.setLongitudeDeg( pos.getLongitudeDeg()
291 + (speed_east_deg_sec - wind_speed_from_east_deg_sec) * dt );
293 // adjust vertical speed for acceleration of gravity and buoyancy
294 vs -= (_gravity - _buoyancy) * dt;
296 // adjust altitude (feet)
297 altitude_ft += vs * dt;
298 pos.setElevationFt(altitude_ft);
300 // recalculate pitch (velocity vector) if aerostabilized
301 /*cout << _name << ": " << "aero_stabilised " << _aero_stabilised
302 << " pitch " << pitch <<" vs " << vs <<endl ;*/
304 if (_aero_stabilised)
305 pitch = atan2( vs, hs ) * SG_RADIANS_TO_DEGREES;
307 // recalculate total speed
308 speed = sqrt( vs * vs + hs * hs) / SG_KT_TO_FPS;
310 //do impacts and collisions
311 if (_report_impact && !_impact_reported)
314 if (_report_collision && !_collision_reported)
317 // set destruction flag if altitude less than sea level -1000
318 if (altitude_ft < -1000.0)
323 double FGAIBallistic::_getTime() const {
324 // cout << "life timer 2" << _life_timer << endl;
328 void FGAIBallistic::handle_impact() {
330 const SGMaterial* material;
332 // try terrain intersection
333 if (!globals->get_scenery()->get_elevation_m(pos.getLatitudeDeg(), pos.getLongitudeDeg(),
334 10000.0, elevation_m, &material))
338 const vector<string> names = material->get_names();
341 _mat_name = names[0].c_str();
343 _solid = material->get_solid();
344 _load_resistance = material->get_load_resistance();
345 props->setStringValue("material/name", _mat_name.c_str());
346 //cout << "material " << _mat_name << " solid " << _solid << " load " << _load_resistance << endl;
349 _ht_agl_ft = pos.getElevationFt() - elevation_m * SG_METER_TO_FEET;
351 // report impact by setting properties
352 if (_ht_agl_ft <= 0) {
353 SG_LOG(SG_GENERAL, SG_DEBUG, "AIBallistic: terrain impact");
354 report_impact(elevation_m);
355 _impact_reported = true;
359 void FGAIBallistic::handle_collision()
361 const FGAIBase *collision = manager->calcCollision(pos.getElevationFt(),
362 pos.getLatitudeDeg(),pos.getLongitudeDeg(), _fuse_range);
365 SG_LOG(SG_GENERAL, SG_DEBUG, "AIBallistic: HIT!");
366 report_impact(pos.getElevationM(), collision);
367 _collision_reported = true;
371 void FGAIBallistic::report_impact(double elevation, const FGAIBase *object)
373 _impact_lat = pos.getLatitudeDeg();
374 _impact_lon = pos.getLongitudeDeg();
375 _impact_elev = elevation;
376 _impact_speed = speed * SG_KT_TO_MPS;
378 _impact_pitch = pitch;
381 SGPropertyNode *n = props->getNode("impact", true);
383 n->setStringValue("type", object->getTypeString());
385 n->setStringValue("type", "terrain");
387 n->setDoubleValue("longitude-deg", _impact_lon);
388 n->setDoubleValue("latitude-deg", _impact_lat);
389 n->setDoubleValue("elevation-m", _impact_elev);
390 n->setDoubleValue("heading-deg", _impact_hdg);
391 n->setDoubleValue("pitch-deg", _impact_pitch);
392 n->setDoubleValue("roll-deg", _impact_roll);
393 n->setDoubleValue("speed-mps", _impact_speed);
395 _impact_report_node->setStringValue(props->getPath());