src/FDM/YASim/FGFDM.cpp

   1 #ifdef HAVE_CONFIG_H
   2 #  include "config.h"
   3 #endif
   4
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7
   8 #include <Main/fg_props.hxx>
   9
  10 #include "Math.hpp"
  11 #include "Jet.hpp"
  12 #include "SimpleJet.hpp"
  13 #include "Gear.hpp"
  14 #include "Hook.hpp"
  15 #include "Launchbar.hpp"
  16 #include "Atmosphere.hpp"
  17 #include "PropEngine.hpp"
  18 #include "Propeller.hpp"
  19 #include "PistonEngine.hpp"
  20 #include "TurbineEngine.hpp"
  21 #include "Rotor.hpp"
  22 #include "Rotorpart.hpp"
  23 #include "Hitch.hpp"
  24
  25 #include "FGFDM.hpp"
  26
  27 namespace yasim {
  28
  29 // Some conversion factors
  30 static const float KTS2MPS = 0.514444444444;
  31 static const float FT2M = 0.3048;
  32 static const float DEG2RAD = 0.0174532925199;
  33 static const float RPM2RAD = 0.10471975512;
  34 static const float LBS2N = 4.44822;
  35 static const float LBS2KG = 0.45359237;
  36 static const float KG2LBS = 2.2046225;
  37 static const float CM2GALS = 264.172037284;
  38 static const float HP2W = 745.700;
  39 static const float INHG2PA = 3386.389;
  40 static const float K2DEGF = 1.8;
  41 static const float K2DEGFOFFSET = -459.4;
  42 static const float CIN2CM = 1.6387064e-5;
  43 static const float YASIM_PI = 3.14159265358979323846;
  44
  45 static const float NM2FTLB = (1/(LBS2N*FT2M));
  46
  47 // Stubs, so that this can be compiled without the FlightGear
  48 // binary.  What's the best way to handle this?
  49
  50 //     float fgGetFloat(char* name, float def) { return 0; }
  51 //     void fgSetFloat(char* name, float val) {}
  52
  53 FGFDM::FGFDM()
  54 {
  55     _vehicle_radius = 0.0f;
  56
  57     _nextEngine = 0;
  58
  59     // Map /controls/flight/elevator to the approach elevator control.  This
  60     // should probably be settable, but there are very few aircraft
  61     // who trim their approaches using things other than elevator.
  62     _airplane.setElevatorControl(parseAxis("/controls/flight/elevator-trim"));
  63
  64     // FIXME: read seed from somewhere?
  65     int seed = 0;
  66     _turb = new Turbulence(10, seed);
  67 }
  68
  69 FGFDM::~FGFDM()
  70 {
  71     for(int i=0; i<_axes.size(); i++) {
  72         AxisRec* a = (AxisRec*)_axes.get(i);
  73         delete[] a->name;
  74         delete a;
  75     }
  76
  77     for(int i=0; i<_thrusters.size(); i++) {
  78         EngRec* er = (EngRec*)_thrusters.get(i);
  79         delete[] er->prefix;
  80         delete er->eng;
  81         delete er;
  82     }
  83
  84     for(int i=0; i<_weights.size(); i++) {
  85         WeightRec* wr = (WeightRec*)_weights.get(i);
  86         delete[] wr->prop;
  87         delete wr;
  88     }
  89
  90     for(int i=0; i<_controlProps.size(); i++)
  91         delete (PropOut*)_controlProps.get(i);
  92
  93     delete _turb;
  94 }
  95
  96 void FGFDM::iterate(float dt)
  97 {
  98     getExternalInput(dt);
  99     _airplane.iterate(dt);
 100
 101     // Do fuel stuff
 102     for(int i=0; i<_airplane.numThrusters(); i++) {
 103         Thruster* t = _airplane.getThruster(i);
 104
 105         bool out_of_fuel = _fuel_props[i]._out_of_fuel->getBoolValue();
 106         t->setFuelState(!out_of_fuel);
 107
 108         double consumed = _fuel_props[i]._fuel_consumed_lbs->getDoubleValue();
 109         _fuel_props[i]._fuel_consumed_lbs->setDoubleValue(
 110                 consumed + dt * KG2LBS * t->getFuelFlow());
 111     }
 112     for(int i=0; i<_airplane.numTanks(); i++) {
 113         _airplane.setFuel(i, LBS2KG * _tank_level_lbs[i]->getFloatValue());
 114     }
 115     _airplane.calcFuelWeights();
 116
 117     setOutputProperties(dt);
 118 }
 119
 120 Airplane* FGFDM::getAirplane()
 121 {
 122     return &_airplane;
 123 }
 124
 125 void FGFDM::init()
 126 {
 127     _turb_magnitude_norm = fgGetNode("/environment/turbulence/magnitude-norm", true);
 128     _turb_rate_hz        = fgGetNode("/environment/turbulence/rate-hz", true);
 129     _gross_weight_lbs    = fgGetNode("/yasim/gross-weight-lbs", true);
 130
 131     // Allows the user to start with something other than full fuel
 132     _airplane.setFuelFraction(fgGetFloat("/sim/fuel-fraction", 1));
 133
 134     // stash engine/thruster properties
 135     _thrust_props.clear();
 136     for (int i=0; i<_thrusters.size(); i++) {
 137         SGPropertyNode_ptr node = fgGetNode("engines/engine", i, true);
 138         Thruster* t = ((EngRec*)_thrusters.get(i))->eng;
 139
 140         ThrusterProps tp;
 141         tp._running =       node->getChild("running", 0, true);
 142         tp._cranking =      node->getChild("cranking", 0, true);
 143         tp._prop_thrust =   node->getChild("prop-thrust", 0, true); // Deprecated name
 144         tp._thrust_lbs =    node->getChild("thrust-lbs", 0, true);
 145         tp._fuel_flow_gph = node->getChild("fuel-flow-gph", 0, true);
 146
 147         if(t->getPropEngine())
 148         {
 149             tp._rpm = node->getChild("rpm", 0, true);
 150             tp._torque_ftlb = node->getChild("torque-ftlb", 0, true);
 151
 152             PropEngine* p = t->getPropEngine();
 153             if(p->getEngine()->isPistonEngine())
 154             {
 155                 tp._mp_osi =   node->getChild("mp-osi",   0, true);
 156                 tp._mp_inhg =  node->getChild("mp-inhg",  0, true);
 157                 tp._egt_degf = node->getChild("egt-degf", 0, true);
 158
 159                 tp._oil_temperature_degf = node->getChild("oil-temperature-degf", 0, true);
 160                 tp._boost_gauge_inhg =     node->getChild("boost-gauge-inhg", 0, true);
 161             } else if(p->getEngine()->isTurbineEngine()) {
 162                 tp._n2 = node->getChild("n2", 0, true);
 163             }
 164         }
 165
 166         if(t->getJet())
 167         {
 168             tp._n1 =       node->getChild("n1",       0, true);
 169             tp._n2 =       node->getChild("n2",       0, true);
 170             tp._epr =      node->getChild("epr",      0, true);
 171             tp._egt_degf = node->getChild("egt-degf", 0, true);
 172         }
 173         _thrust_props.push_back(tp);
 174     }
 175
 176     // stash properties for fuel state
 177     _fuel_props.clear();
 178     for(int i=0; i<_airplane.numThrusters(); i++) {
 179         SGPropertyNode_ptr e = fgGetNode("engines/engine", i, true);
 180         FuelProps f;
 181         f._out_of_fuel       = e->getChild("out-of-fuel", 0, true);
 182         f._fuel_consumed_lbs = e->getChild("fuel-consumed-lbs", 0, true);
 183         _fuel_props.push_back(f);
 184     }
 185
 186     // initialize tanks and stash properties for tank level
 187     _tank_level_lbs.clear();
 188     for(int i=0; i<_airplane.numTanks(); i++) {
 189         char buf[256];
 190         sprintf(buf, "/consumables/fuel/tank[%d]/level-lbs", i);
 191         fgSetDouble(buf, _airplane.getFuel(i) * KG2LBS);
 192         _tank_level_lbs.push_back(fgGetNode(buf, true));
 193
 194         double density = _airplane.getFuelDensity(i);
 195         sprintf(buf, "/consumables/fuel/tank[%d]/density-ppg", i);
 196         fgSetDouble(buf, density * (KG2LBS/CM2GALS));
 197
 198 // set in TankProperties class
 199 //        sprintf(buf, "/consumables/fuel/tank[%d]/level-gal_us", i);
 200 //        fgSetDouble(buf, _airplane.getFuel(i) * CM2GALS / density);
 201
 202         sprintf(buf, "/consumables/fuel/tank[%d]/capacity-gal_us", i);
 203         fgSetDouble(buf, CM2GALS * _airplane.getTankCapacity(i)/density);
 204     }
 205
 206     // This has a nasty habit of being false at startup.  That's not
 207     // good.
 208     fgSetBool("/controls/gear/gear-down", true);
 209
 210     _airplane.getModel()->setTurbulence(_turb);
 211 }
 212
 213 // Not the worlds safest parser.  But it's short & sweet.
 214 void FGFDM::startElement(const char* name, const XMLAttributes &atts)
 215 {
 216     XMLAttributes* a = (XMLAttributes*)&atts;
 217     float v[3];
 218     char buf[64];
 219
 220     if(eq(name, "airplane")) {
 221         _airplane.setWeight(attrf(a, "mass") * LBS2KG);
 222         if(a->hasAttribute("version")) {
 223           _airplane.setVersion( a->getValue("version") );
 224         }
 225 #if defined(ENABLE_DEV_WARNINGS)
 226         if( !_airplane.isVersionOrNewer( Version::YASIM_VERSION_CURRENT ) ) {
 227           SG_LOG(SG_FLIGHT,SG_ALERT, "This aircraft does not use the latest yasim configuration version.");
 228         }
 229 #endif
 230     } else if(eq(name, "approach")) {
 231         float spd = attrf(a, "speed") * KTS2MPS;
 232         float alt = attrf(a, "alt", 0) * FT2M;
 233         float aoa = attrf(a, "aoa", 0) * DEG2RAD;
 234         float gla = attrf(a, "glide-angle", 0) * DEG2RAD;
 235         _airplane.setApproach(spd, alt, aoa, attrf(a, "fuel", 0.2),gla);
 236         _cruiseCurr = false;
 237     } else if(eq(name, "cruise")) {
 238         float spd = attrf(a, "speed") * KTS2MPS;
 239         float alt = attrf(a, "alt") * FT2M;
 240         float gla = attrf(a, "glide-angle", 0) * DEG2RAD;
 241         _airplane.setCruise(spd, alt, attrf(a, "fuel", 0.5),gla);
 242         _cruiseCurr = true;
 243     } else if(eq(name, "solve-weight")) {
 244         int idx = attri(a, "idx");
 245         float wgt = attrf(a, "weight") * LBS2KG;
 246         _airplane.addSolutionWeight(!_cruiseCurr, idx, wgt);
 247     } else if(eq(name, "cockpit")) {
 248         v[0] = attrf(a, "x");
 249         v[1] = attrf(a, "y");
 250         v[2] = attrf(a, "z");
 251         _airplane.setPilotPos(v);
 252     } else if(eq(name, "rotor")) {
 253         _airplane.getModel()->getRotorgear()->addRotor(parseRotor(a, name));
 254     } else if(eq(name, "rotorgear")) {
 255         Rotorgear* r = _airplane.getModel()->getRotorgear();
 256         _currObj = r;
 257         #define p(x) if (a->hasAttribute(#x)) r->setParameter((char *)#x,attrf(a,#x) );
 258         #define p2(x,y) if (a->hasAttribute(y)) r->setParameter((char *)#x,attrf(a,y) );
 259         p2(max_power_engine,"max-power-engine")
 260         p2(engine_prop_factor,"engine-prop-factor")
 261         p(yasimdragfactor)
 262         p(yasimliftfactor)
 263         p2(max_power_rotor_brake,"max-power-rotor-brake")
 264         p2(rotorgear_friction,"rotorgear-friction")
 265         p2(engine_accel_limit,"engine-accel-limit")
 266         #undef p
 267         #undef p2
 268         r->setInUse();
 269     } else if(eq(name, "wing")) {
 270         _airplane.setWing(parseWing(a, name, &_airplane));
 271     } else if(eq(name, "hstab")) {
 272         _airplane.setTail(parseWing(a, name, &_airplane));
 273     } else if(eq(name, "vstab") || eq(name, "mstab")) {
 274         _airplane.addVStab(parseWing(a, name, &_airplane));
 275     } else if(eq(name, "piston-engine")) {
 276         parsePistonEngine(a);
 277     } else if(eq(name, "turbine-engine")) {
 278         parseTurbineEngine(a);
 279     } else if(eq(name, "propeller")) {
 280         parsePropeller(a);
 281     } else if(eq(name, "thruster")) {
 282         SimpleJet* j = new SimpleJet();
 283         _currObj = j;
 284         v[0] = attrf(a, "x"); v[1] = attrf(a, "y"); v[2] = attrf(a, "z");
 285         j->setPosition(v);
 286         _airplane.addThruster(j, 0, v);
 287         v[0] = attrf(a, "vx"); v[1] = attrf(a, "vy"); v[2] = attrf(a, "vz");
 288         j->setDirection(v);
 289         j->setThrust(attrf(a, "thrust") * LBS2N);
 290     } else if(eq(name, "jet")) {
 291         Jet* j = new Jet();
 292         _currObj = j;
 293         v[0] = attrf(a, "x");
 294         v[1] = attrf(a, "y");
 295         v[2] = attrf(a, "z");
 296         float mass = attrf(a, "mass") * LBS2KG;
 297         j->setMaxThrust(attrf(a, "thrust") * LBS2N,
 298                         attrf(a, "afterburner", 0) * LBS2N);
 299         j->setVectorAngle(attrf(a, "rotate", 0) * DEG2RAD);
 300         j->setReverseThrust(attrf(a, "reverse", 0.2));
 301
 302         float n1min = attrf(a, "n1-idle", 55);
 303         float n1max = attrf(a, "n1-max", 102);
 304         float n2min = attrf(a, "n2-idle", 73);
 305         float n2max = attrf(a, "n2-max", 103);
 306         j->setRPMs(n1min, n1max, n2min, n2max);
 307
 308         j->setTSFC(attrf(a, "tsfc", 0.8));
 309         if(a->hasAttribute("egt"))  j->setEGT(attrf(a, "egt"));
 310         if(a->hasAttribute("epr"))  j->setEPR(attrf(a, "epr"));
 311         if(a->hasAttribute("exhaust-speed"))
 312             j->setVMax(attrf(a, "exhaust-speed") * KTS2MPS);
 313         if(a->hasAttribute("spool-time"))
 314             j->setSpooling(attrf(a, "spool-time"));
 315
 316         j->setPosition(v);
 317         _airplane.addThruster(j, mass, v);
 318         sprintf(buf, "/engines/engine[%d]", _nextEngine++);
 319         EngRec* er = new EngRec();
 320         er->eng = j;
 321         er->prefix = dup(buf);
 322         _thrusters.add(er);
 323     } else if(eq(name, "hitch")) {
 324         Hitch* h = new Hitch(a->getValue("name"));
 325         _currObj = h;
 326         v[0] = attrf(a, "x");
 327         v[1] = attrf(a, "y");
 328         v[2] = attrf(a, "z");
 329         h->setPosition(v);
 330         if(a->hasAttribute("force-is-calculated-by-other")) h->setForceIsCalculatedByOther(attrb(a,"force-is-calculated-by-other"));
 331         _airplane.addHitch(h);
 332     } else if(eq(name, "tow")) {
 333         Hitch* h = (Hitch*)_currObj;
 334         if(a->hasAttribute("length"))
 335             h->setTowLength(attrf(a, "length"));
 336         if(a->hasAttribute("elastic-constant"))
 337             h->setTowElasticConstant(attrf(a, "elastic-constant"));
 338         if(a->hasAttribute("break-force"))
 339             h->setTowBreakForce(attrf(a, "break-force"));
 340         if(a->hasAttribute("weight-per-meter"))
 341             h->setTowWeightPerM(attrf(a, "weight-per-meter"));
 342         if(a->hasAttribute("mp-auto-connect-period"))
 343             h->setMpAutoConnectPeriod(attrf(a, "mp-auto-connect-period"));
 344     } else if(eq(name, "winch")) {
 345         Hitch* h = (Hitch*)_currObj;
 346         double pos[3];
 347         pos[0] = attrd(a, "x",0);
 348         pos[1] = attrd(a, "y",0);
 349         pos[2] = attrd(a, "z",0);
 350         h->setWinchPosition(pos);
 351         if(a->hasAttribute("max-speed"))
 352             h->setWinchMaxSpeed(attrf(a, "max-speed"));
 353         if(a->hasAttribute("power"))
 354             h->setWinchPower(attrf(a, "power") * 1000);
 355         if(a->hasAttribute("max-force"))
 356             h->setWinchMaxForce(attrf(a, "max-force"));
 357         if(a->hasAttribute("initial-tow-length"))
 358             h->setWinchInitialTowLength(attrf(a, "initial-tow-length"));
 359         if(a->hasAttribute("max-tow-length"))
 360             h->setWinchMaxTowLength(attrf(a, "max-tow-length"));
 361         if(a->hasAttribute("min-tow-length"))
 362             h->setWinchMinTowLength(attrf(a, "min-tow-length"));
 363     } else if(eq(name, "gear")) {
 364         Gear* g = new Gear();
 365         _currObj = g;
 366         v[0] = attrf(a, "x");
 367         v[1] = attrf(a, "y");
 368         v[2] = attrf(a, "z");
 369         g->setPosition(v);
 370         float nrm = Math::mag3(v);
 371         if (_vehicle_radius < nrm)
 372             _vehicle_radius = nrm;
 373         if(a->hasAttribute("upx")) {
 374             v[0] = attrf(a, "upx");
 375             v[1] = attrf(a, "upy");
 376             v[2] = attrf(a, "upz");
 377             Math::unit3(v, v);
 378         } else {
 379             v[0] = 0;
 380             v[1] = 0;
 381             v[2] = 1;
 382         }
 383         for(int i=0; i<3; i++)
 384             v[i] *= attrf(a, "compression", 1);
 385         g->setCompression(v);
 386         g->setBrake(attrf(a, "skid", 0));
 387         g->setInitialLoad(attrf(a, "initial-load", 0));
 388         g->setStaticFriction(attrf(a, "sfric", 0.8));
 389         g->setDynamicFriction(attrf(a, "dfric", 0.7));
 390         g->setSpring(attrf(a, "spring", 1));
 391         g->setDamping(attrf(a, "damp", 1));
 392         if(a->hasAttribute("on-water")) g->setOnWater(attrb(a,"on-water"));
 393         if(a->hasAttribute("on-solid")) g->setOnSolid(attrb(a,"on-solid"));
 394         if(a->hasAttribute("ignored-by-solver")) g->setIgnoreWhileSolving(attrb(a,"ignored-by-solver"));
 395         g->setSpringFactorNotPlaning(attrf(a, "spring-factor-not-planing", 1));
 396         g->setSpeedPlaning(attrf(a, "speed-planing", 0) * KTS2MPS);
 397         g->setReduceFrictionByExtension(attrf(a, "reduce-friction-by-extension", 0));
 398         _airplane.addGear(g);
 399     } else if(eq(name, "hook")) {
 400         Hook* h = new Hook();
 401         _currObj = h;
 402         v[0] = attrf(a, "x");
 403         v[1] = attrf(a, "y");
 404         v[2] = attrf(a, "z");
 405         h->setPosition(v);
 406         float length = attrf(a, "length", 1.0);
 407         h->setLength(length);
 408         float nrm = length+Math::mag3(v);
 409         if (_vehicle_radius < nrm)
 410             _vehicle_radius = nrm;
 411         h->setDownAngle(attrf(a, "down-angle", 70) * DEG2RAD);
 412         h->setUpAngle(attrf(a, "up-angle", 0) * DEG2RAD);
 413         _airplane.addHook(h);
 414     } else if(eq(name, "launchbar")) {
 415         Launchbar* l = new Launchbar();
 416         _currObj = l;
 417         v[0] = attrf(a, "x");
 418         v[1] = attrf(a, "y");
 419         v[2] = attrf(a, "z");
 420         l->setLaunchbarMount(v);
 421         v[0] = attrf(a, "holdback-x", v[0]);
 422         v[1] = attrf(a, "holdback-y", v[1]);
 423         v[2] = attrf(a, "holdback-z", v[2]);
 424         l->setHoldbackMount(v);
 425         float length = attrf(a, "length", 1.0);
 426         l->setLength(length);
 427         l->setDownAngle(attrf(a, "down-angle", 45) * DEG2RAD);
 428         l->setUpAngle(attrf(a, "up-angle", -45) * DEG2RAD);
 429         l->setHoldbackLength(attrf(a, "holdback-length", 2.0));
 430         _airplane.addLaunchbar(l);
 431     } else if(eq(name, "fuselage")) {
 432         float b[3];
 433         v[0] = attrf(a, "ax");
 434         v[1] = attrf(a, "ay");
 435         v[2] = attrf(a, "az");
 436         b[0] = attrf(a, "bx");
 437         b[1] = attrf(a, "by");
 438         b[2] = attrf(a, "bz");
 439         float taper = attrf(a, "taper", 1);
 440         float mid = attrf(a, "midpoint", 0.5);
 441         if (_airplane.isVersionOrNewer(Version::YASIM_VERSION_32)) {
 442             // A fuselage's "midpoint" XML attribute is defined from the
 443             // fuselage's front end, but the Fuselage object's internal
 444             // "mid" attribute is actually defined from the rear end.
 445             // Thus YASim's original interpretation of "midpoint" was wrong.
 446             // Complement the "midpoint" value to ensure the fuselage
 447             // points the right way.
 448             mid = 1 - mid;
 449         }
 450         float cx = attrf(a, "cx", 1);
 451         float cy = attrf(a, "cy", 1);
 452         float cz = attrf(a, "cz", 1);
 453         float idrag = attrf(a, "idrag", 1);
 454         _airplane.addFuselage(v, b, attrf(a, "width"), taper, mid,
 455             cx, cy, cz, idrag);
 456     } else if(eq(name, "tank")) {
 457         v[0] = attrf(a, "x");
 458         v[1] = attrf(a, "y");
 459         v[2] = attrf(a, "z");
 460         float density = 6.0; // gasoline, in lbs/gal
 461         if(a->hasAttribute("jet")) density = 6.72;
 462         density *= LBS2KG*CM2GALS;
 463         _airplane.addTank(v, attrf(a, "capacity") * LBS2KG, density);
 464     } else if(eq(name, "ballast")) {
 465         v[0] = attrf(a, "x");
 466         v[1] = attrf(a, "y");
 467         v[2] = attrf(a, "z");
 468         _airplane.addBallast(v, attrf(a, "mass") * LBS2KG);
 469     } else if(eq(name, "weight")) {
 470         parseWeight(a);
 471     } else if(eq(name, "stall")) {
 472         Wing* w = (Wing*)_currObj;
 473         w->setStall(attrf(a, "aoa") * DEG2RAD);
 474         w->setStallWidth(attrf(a, "width", 2) * DEG2RAD);
 475         w->setStallPeak(attrf(a, "peak", 1.5));
 476     } else if(eq(name, "flap0")) {
 477         ((Wing*)_currObj)->setFlap0(attrf(a, "start"), attrf(a, "end"),
 478                                     attrf(a, "lift"), attrf(a, "drag"));
 479     } else if(eq(name, "flap1")) {
 480         ((Wing*)_currObj)->setFlap1(attrf(a, "start"), attrf(a, "end"),
 481                                     attrf(a, "lift"), attrf(a, "drag"));
 482     } else if(eq(name, "slat")) {
 483         ((Wing*)_currObj)->setSlat(attrf(a, "start"), attrf(a, "end"),
 484                                    attrf(a, "aoa"), attrf(a, "drag"));
 485     } else if(eq(name, "spoiler")) {
 486         ((Wing*)_currObj)->setSpoiler(attrf(a, "start"), attrf(a, "end"),
 487                                       attrf(a, "lift"), attrf(a, "drag"));
 488     /* } else if(eq(name, "collective")) {
 489         ((Rotor*)_currObj)->setcollective(attrf(a, "min"), attrf(a, "max"));
 490     } else if(eq(name, "cyclic")) {
 491         ((Rotor*)_currObj)->setcyclic(attrf(a, "ail"), attrf(a, "ele"));
 492     */
 493     } else if(eq(name, "actionpt")) {
 494         v[0] = attrf(a, "x");
 495         v[1] = attrf(a, "y");
 496         v[2] = attrf(a, "z");
 497         ((Thruster*)_currObj)->setPosition(v);
 498     } else if(eq(name, "dir")) {
 499         v[0] = attrf(a, "x");
 500         v[1] = attrf(a, "y");
 501         v[2] = attrf(a, "z");
 502         ((Thruster*)_currObj)->setDirection(v);
 503     } else if(eq(name, "control-setting")) {
 504         // A cruise or approach control setting
 505         const char* axis = a->getValue("axis");
 506         float value = attrf(a, "value", 0);
 507         if(_cruiseCurr)
 508             _airplane.addCruiseControl(parseAxis(axis), value);
 509         else
 510             _airplane.addApproachControl(parseAxis(axis), value);
 511     } else if(eq(name, "control-input")) {
 512
 513         // A mapping of input property to a control
 514         int axis = parseAxis(a->getValue("axis"));
 515         int control = parseOutput(a->getValue("control"));
 516         int opt = 0;
 517         opt |= a->hasAttribute("split") ? ControlMap::OPT_SPLIT : 0;
 518         opt |= a->hasAttribute("invert") ? ControlMap::OPT_INVERT : 0;
 519         opt |= a->hasAttribute("square") ? ControlMap::OPT_SQUARE : 0;
 520
 521         ControlMap* cm = _airplane.getControlMap();
 522         if(a->hasAttribute("src0")) {
 523                            cm->addMapping(axis, control, _currObj, opt,
 524                            attrf(a, "src0"), attrf(a, "src1"),
 525                            attrf(a, "dst0"), attrf(a, "dst1"));
 526         } else {
 527             cm->addMapping(axis, control, _currObj, opt);
 528         }
 529     } else if(eq(name, "control-output")) {
 530         // A property output for a control on the current object
 531         ControlMap* cm = _airplane.getControlMap();
 532         int type = parseOutput(a->getValue("control"));
 533         int handle = cm->getOutputHandle(_currObj, type);
 534
 535         PropOut* p = new PropOut();
 536         p->prop = fgGetNode(a->getValue("prop"), true);
 537         p->handle = handle;
 538         p->type = type;
 539         p->left = !(a->hasAttribute("side") &&
 540                         eq("right", a->getValue("side")));
 541         p->min = attrf(a, "min", cm->rangeMin(type));
 542         p->max = attrf(a, "max", cm->rangeMax(type));
 543         _controlProps.add(p);
 544
 545     } else if(eq(name, "control-speed")) {
 546         ControlMap* cm = _airplane.getControlMap();
 547         int type = parseOutput(a->getValue("control"));
 548         int handle = cm->getOutputHandle(_currObj, type);
 549         float time = attrf(a, "transition-time", 0);
 550
 551         cm->setTransitionTime(handle, time);
 552     } else {
 553         SG_LOG(SG_FLIGHT,SG_ALERT,"Unexpected tag '"
 554                << name << "' found in YASim aircraft description");
 555         exit(1);
 556     }
 557 }
 558
 559 void FGFDM::getExternalInput(float dt)
 560 {
 561     char buf[256];
 562
 563     _turb->setMagnitude(_turb_magnitude_norm->getFloatValue());
 564     _turb->update(dt, _turb_rate_hz->getFloatValue());
 565
 566     // The control axes
 567     ControlMap* cm = _airplane.getControlMap();
 568     cm->reset();
 569
 570     for(int i=0; i<_axes.size(); i++) {
 571         AxisRec* a = (AxisRec*)_axes.get(i);
 572         float val = fgGetFloat(a->name, 0);
 573         cm->setInput(a->handle, val);
 574     }
 575     cm->applyControls(dt);
 576
 577     // Weights
 578     for(int i=0; i<_weights.size(); i++) {
 579         WeightRec* wr = (WeightRec*)_weights.get(i);
 580         _airplane.setWeight(wr->handle, LBS2KG * fgGetFloat(wr->prop));
 581     }
 582
 583     for(int i=0; i<_thrusters.size(); i++) {
 584         EngRec* er = (EngRec*)_thrusters.get(i);
 585         Thruster* t = er->eng;
 586
 587         if(t->getPropEngine()) {
 588             PropEngine* p = t->getPropEngine();
 589             sprintf(buf, "%s/rpm", er->prefix);
 590             p->setOmega(fgGetFloat(buf, 500) * RPM2RAD);
 591         }
 592     }
 593 }
 594
 595 // Linearly "seeks" a property by the specified fraction of the way to
 596 // the target value.  Used to emulate "slowly changing" output values.
 597 static void moveprop(SGPropertyNode* node, const char* prop,
 598                     float target, float frac)
 599 {
 600     float val = node->getFloatValue(prop);
 601     if(frac > 1) frac = 1;
 602     if(frac < 0) frac = 0;
 603     val += (target - val) * frac;
 604     node->setFloatValue(prop, val);
 605 }
 606
 607 void FGFDM::setOutputProperties(float dt)
 608 {
 609     float grossWgt = _airplane.getModel()->getBody()->getTotalMass() * KG2LBS;
 610     _gross_weight_lbs->setFloatValue(grossWgt);
 611
 612     ControlMap* cm = _airplane.getControlMap();
 613     for(int i=0; i<_controlProps.size(); i++) {
 614         PropOut* p = (PropOut*)_controlProps.get(i);
 615         float val = (p->left
 616                      ? cm->getOutput(p->handle)
 617                      : cm->getOutputR(p->handle));
 618         float rmin = cm->rangeMin(p->type);
 619         float rmax = cm->rangeMax(p->type);
 620         float frac = (val - rmin) / (rmax - rmin);
 621         val = frac*(p->max - p->min) + p->min;
 622         p->prop->setFloatValue(val);
 623     }
 624
 625     for(int i=0; i<_airplane.getRotorgear()->getNumRotors(); i++) {
 626         Rotor*r=(Rotor*)_airplane.getRotorgear()->getRotor(i);
 627         int j = 0;
 628         float f;
 629         char b[256];
 630         while((j = r->getValueforFGSet(j, b, &f)))
 631             if(b[0]) fgSetFloat(b,f);
 632         j=0;
 633         while((j = _airplane.getRotorgear()->getValueforFGSet(j, b, &f)))
 634             if(b[0]) fgSetFloat(b,f);
 635         for(j=0; j < r->numRotorparts(); j+=r->numRotorparts()>>2) {
 636             Rotorpart* s = (Rotorpart*)r->getRotorpart(j);
 637             char *b;
 638             int k;
 639             for(k=0; k<2; k++) {
 640                 b=s->getAlphaoutput(k);
 641                 if(b[0]) fgSetFloat(b, s->getAlpha(k));
 642             }
 643         }
 644     }
 645
 646     // Use the density of the first tank, or a dummy value if no tanks
 647     float fuelDensity = 1.0;
 648     if(_airplane.numTanks())
 649         fuelDensity = _airplane.getFuelDensity(0);
 650     for(int i=0; i<_thrusters.size(); i++) {
 651         EngRec* er = (EngRec*)_thrusters.get(i);
 652         Thruster* t = er->eng;
 653         SGPropertyNode * node = fgGetNode("engines/engine", i, true);
 654
 655         ThrusterProps& tp = _thrust_props[i];
 656
 657         // Set: running, cranking, prop-thrust, max-hp, power-pct
 658         tp._running->setBoolValue(t->isRunning());
 659         tp._cranking->setBoolValue(t->isCranking());
 660
 661         float tmp[3];
 662         t->getThrust(tmp);
 663         float lbs = Math::mag3(tmp) * (KG2LBS/9.8);
 664         tp._prop_thrust->setFloatValue(lbs); // Deprecated name
 665         tp._thrust_lbs->setFloatValue(lbs);
 666         tp._fuel_flow_gph->setFloatValue(
 667                 (t->getFuelFlow()/fuelDensity) * 3600 * CM2GALS);
 668
 669         if(t->getPropEngine()) {
 670             PropEngine* p = t->getPropEngine();
 671             tp._rpm->setFloatValue(p->getOmega() * (1/RPM2RAD));
 672             tp._torque_ftlb->setFloatValue(
 673                     p->getEngine()->getTorque() * NM2FTLB);
 674
 675             if(p->getEngine()->isPistonEngine()) {
 676                 PistonEngine* pe = p->getEngine()->isPistonEngine();
 677                 tp._mp_osi->setFloatValue(pe->getMP() * (1/INHG2PA));
 678                 tp._mp_inhg->setFloatValue(pe->getMP() * (1/INHG2PA));
 679                 tp._egt_degf->setFloatValue(
 680                         pe->getEGT() * K2DEGF + K2DEGFOFFSET);
 681                 tp._oil_temperature_degf->setFloatValue(
 682                         pe->getOilTemp() * K2DEGF + K2DEGFOFFSET);
 683                 tp._boost_gauge_inhg->setFloatValue(
 684                         pe->getBoost() * (1/INHG2PA));
 685             } else if(p->getEngine()->isTurbineEngine()) {
 686                 TurbineEngine* te = p->getEngine()->isTurbineEngine();
 687                 tp._n2->setFloatValue(te->getN2());
 688             }
 689         }
 690
 691         if(t->getJet()) {
 692             Jet* j = t->getJet();
 693             tp._n1->setFloatValue(j->getN1());
 694             tp._n2->setFloatValue(j->getN2());
 695             tp._epr->setFloatValue(j->getEPR());
 696             tp._egt_degf->setFloatValue(
 697                     j->getEGT() * K2DEGF + K2DEGFOFFSET);
 698
 699             // These are "unmodeled" values that are still needed for
 700             // many cockpits.  Tie them all to the N1 speed, but
 701             // normalize the numbers to the range [0:1] so the
 702             // cockpit code can scale them to the right values.
 703             float pnorm = j->getPerfNorm();
 704             moveprop(node, "oilp-norm", pnorm, dt/3); // 3s seek time
 705             moveprop(node, "oilt-norm", pnorm, dt/30); // 30s
 706             moveprop(node, "itt-norm", pnorm, dt/1); // 1s
 707         }
 708     }
 709 }
 710
 711 Wing* FGFDM::parseWing(XMLAttributes* a, const char* type, Version * version)
 712 {
 713     Wing* w = new Wing(version);
 714
 715     float defDihed = 0;
 716     if(eq(type, "vstab"))
 717         defDihed = 90;
 718     else
 719         w->setMirror(true);
 720
 721     float pos[3];
 722     pos[0] = attrf(a, "x");
 723     pos[1] = attrf(a, "y");
 724     pos[2] = attrf(a, "z");
 725     w->setBase(pos);
 726
 727     w->setLength(attrf(a, "length"));
 728     w->setChord(attrf(a, "chord"));
 729     w->setSweep(attrf(a, "sweep", 0) * DEG2RAD);
 730     w->setTaper(attrf(a, "taper", 1));
 731     w->setDihedral(attrf(a, "dihedral", defDihed) * DEG2RAD);
 732     w->setCamber(attrf(a, "camber", 0));
 733
 734     // These come in with positive indicating positive AoA, but the
 735     // internals expect a rotation about the left-pointing Y axis, so
 736     // invert the sign.
 737     w->setIncidence(attrf(a, "incidence", 0) * DEG2RAD * -1);
 738     w->setTwist(attrf(a, "twist", 0) * DEG2RAD * -1);
 739
 740     // The 70% is a magic number that sorta kinda seems to match known
 741     // throttle settings to approach speed.
 742     w->setInducedDrag(0.7*attrf(a, "idrag", 1));
 743
 744     float effect = attrf(a, "effectiveness", 1);
 745     w->setDragScale(w->getDragScale()*effect);
 746
 747     _currObj = w;
 748     return w;
 749 }
 750
 751 Rotor* FGFDM::parseRotor(XMLAttributes* a, const char* type)
 752 {
 753     Rotor* w = new Rotor();
 754
 755     // float defDihed = 0;
 756
 757     float pos[3];
 758     pos[0] = attrf(a, "x");
 759     pos[1] = attrf(a, "y");
 760     pos[2] = attrf(a, "z");
 761     w->setBase(pos);
 762
 763     float normal[3];
 764     normal[0] = attrf(a, "nx");
 765     normal[1] = attrf(a, "ny");
 766     normal[2] = attrf(a, "nz");
 767     w->setNormal(normal);
 768
 769     float forward[3];
 770     forward[0] = attrf(a, "fx");
 771     forward[1] = attrf(a, "fy");
 772     forward[2] = attrf(a, "fz");
 773     w->setForward(forward);
 774
 775     w->setMaxCyclicail(attrf(a, "maxcyclicail", 7.6));
 776     w->setMaxCyclicele(attrf(a, "maxcyclicele", 4.94));
 777     w->setMinCyclicail(attrf(a, "mincyclicail", -7.6));
 778     w->setMinCyclicele(attrf(a, "mincyclicele", -4.94));
 779     w->setMaxCollective(attrf(a, "maxcollective", 15.8));
 780     w->setMinCollective(attrf(a, "mincollective", -0.2));
 781     w->setDiameter(attrf(a, "diameter", 10.2));
 782     w->setWeightPerBlade(attrf(a, "weightperblade", 44));
 783     w->setNumberOfBlades(attrf(a, "numblades", 4));
 784     w->setRelBladeCenter(attrf(a, "relbladecenter", 0.7));
 785     w->setDynamic(attrf(a, "dynamic", 0.7));
 786     w->setDelta3(attrf(a, "delta3", 0));
 787     w->setDelta(attrf(a, "delta", 0));
 788     w->setTranslift(attrf(a, "translift", 0.05));
 789     w->setC2(attrf(a, "dragfactor", 1));
 790     w->setStepspersecond(attrf(a, "stepspersecond", 120));
 791     w->setPhiNull((attrf(a, "phi0", 0))*YASIM_PI/180);
 792     w->setRPM(attrf(a, "rpm", 424));
 793     w->setRelLenHinge(attrf(a, "rellenflaphinge", 0.07));
 794     w->setAlpha0((attrf(a, "flap0", -5))*YASIM_PI/180);
 795     w->setAlphamin((attrf(a, "flapmin", -15))/180*YASIM_PI);
 796     w->setAlphamax((attrf(a, "flapmax",  15))*YASIM_PI/180);
 797     w->setAlpha0factor(attrf(a, "flap0factor", 1));
 798     w->setTeeterdamp(attrf(a,"teeterdamp",.0001));
 799     w->setMaxteeterdamp(attrf(a,"maxteeterdamp",1000));
 800     w->setRelLenTeeterHinge(attrf(a,"rellenteeterhinge",0.01));
 801     w->setBalance(attrf(a,"balance",1.0));
 802     w->setMinTiltYaw(attrf(a,"mintiltyaw",0.0));
 803     w->setMinTiltPitch(attrf(a,"mintiltpitch",0.0));
 804     w->setMinTiltRoll(attrf(a,"mintiltroll",0.0));
 805     w->setMaxTiltYaw(attrf(a,"maxtiltyaw",0.0));
 806     w->setMaxTiltPitch(attrf(a,"maxtiltpitch",0.0));
 807     w->setMaxTiltRoll(attrf(a,"maxtiltroll",0.0));
 808     w->setTiltCenterX(attrf(a,"tiltcenterx",0.0));
 809     w->setTiltCenterY(attrf(a,"tiltcentery",0.0));
 810     w->setTiltCenterZ(attrf(a,"tiltcenterz",0.0));
 811     w->setDownwashFactor(attrf(a, "downwashfactor", 1));
 812     if(attrb(a,"ccw"))
 813        w->setCcw(1);
 814     if(attrb(a,"sharedflaphinge"))
 815        w->setSharedFlapHinge(true);
 816
 817     if(a->hasAttribute("name"))
 818        w->setName(a->getValue("name") );
 819     if(a->hasAttribute("alphaout0"))
 820        w->setAlphaoutput(0,a->getValue("alphaout0") );
 821     if(a->hasAttribute("alphaout1"))  w->setAlphaoutput(1,a->getValue("alphaout1") );
 822     if(a->hasAttribute("alphaout2"))  w->setAlphaoutput(2,a->getValue("alphaout2") );
 823     if(a->hasAttribute("alphaout3"))  w->setAlphaoutput(3,a->getValue("alphaout3") );
 824     if(a->hasAttribute("coneout"))  w->setAlphaoutput(4,a->getValue("coneout") );
 825     if(a->hasAttribute("yawout"))   w->setAlphaoutput(5,a->getValue("yawout") );
 826     if(a->hasAttribute("rollout"))  w->setAlphaoutput(6,a->getValue("rollout") );
 827
 828     w->setPitchA(attrf(a, "pitch-a", 10));
 829     w->setPitchB(attrf(a, "pitch-b", 10));
 830     w->setForceAtPitchA(attrf(a, "forceatpitch-a", 3000));
 831     w->setPowerAtPitch0(attrf(a, "poweratpitch-0", 300));
 832     w->setPowerAtPitchB(attrf(a, "poweratpitch-b", 3000));
 833     if(attrb(a,"notorque"))
 834        w->setNotorque(1);
 835
 836 #define p(x) if (a->hasAttribute(#x)) w->setParameter((char *)#x,attrf(a,#x) );
 837 #define p2(x,y) if (a->hasAttribute(y)) w->setParameter((char *)#x,attrf(a,y) );
 838     p2(translift_ve,"translift-ve")
 839     p2(translift_maxfactor,"translift-maxfactor")
 840     p2(ground_effect_constant,"ground-effect-constant")
 841     p2(vortex_state_lift_factor,"vortex-state-lift-factor")
 842     p2(vortex_state_c1,"vortex-state-c1")
 843     p2(vortex_state_c2,"vortex-state-c2")
 844     p2(vortex_state_c3,"vortex-state_c3")
 845     p2(vortex_state_e1,"vortex-state-e1")
 846     p2(vortex_state_e2,"vortex-state-e2")
 847     p(twist)
 848     p2(number_of_segments,"number-of-segments")
 849     p2(number_of_parts,"number-of-parts")
 850     p2(rel_len_where_incidence_is_measured,"rel-len-where-incidence-is-measured")
 851     p(chord)
 852     p(taper)
 853     p2(airfoil_incidence_no_lift,"airfoil-incidence-no-lift")
 854     p2(rel_len_blade_start,"rel-len-blade-start")
 855     p2(incidence_stall_zero_speed,"incidence-stall-zero-speed")
 856     p2(incidence_stall_half_sonic_speed,"incidence-stall-half-sonic-speed")
 857     p2(lift_factor_stall,"lift-factor-stall")
 858     p2(stall_change_over,"stall-change-over")
 859     p2(drag_factor_stall,"drag-factor-stall")
 860     p2(airfoil_lift_coefficient,"airfoil-lift-coefficient")
 861     p2(airfoil_drag_coefficient0,"airfoil-drag-coefficient0")
 862     p2(airfoil_drag_coefficient1,"airfoil-drag-coefficient1")
 863     p2(cyclic_factor,"cyclic-factor")
 864     p2(rotor_correction_factor,"rotor-correction-factor")
 865 #undef p
 866 #undef p2
 867     _currObj = w;
 868     return w;
 869 }
 870
 871 void FGFDM::parsePistonEngine(XMLAttributes* a)
 872 {
 873     float engP = attrf(a, "eng-power") * HP2W;
 874     float engS = attrf(a, "eng-rpm") * RPM2RAD;
 875
 876     PistonEngine* eng = new PistonEngine(engP, engS);
 877
 878     if(a->hasAttribute("displacement"))
 879         eng->setDisplacement(attrf(a, "displacement") * CIN2CM);
 880
 881     if(a->hasAttribute("compression"))
 882         eng->setCompression(attrf(a, "compression"));
 883
 884     if(a->hasAttribute("min-throttle"))
 885         eng->setMinThrottle(attrf(a, "min-throttle"));
 886
 887     if(a->hasAttribute("turbo-mul")) {
 888         float mul = attrf(a, "turbo-mul");
 889         float mp = attrf(a, "wastegate-mp", 1e6) * INHG2PA;
 890         eng->setTurboParams(mul, mp);
 891         eng->setTurboLag(attrf(a, "turbo-lag", 2));
 892     }
 893
 894     if(a->hasAttribute("supercharger"))
 895         eng->setSupercharger(attrb(a, "supercharger"));
 896
 897     ((PropEngine*)_currObj)->setEngine(eng);
 898 }
 899
 900 void FGFDM::parseTurbineEngine(XMLAttributes* a)
 901 {
 902     float power = attrf(a, "eng-power") * HP2W;
 903     float omega = attrf(a, "eng-rpm") * RPM2RAD;
 904     float alt = attrf(a, "alt") * FT2M;
 905     float flatRating = attrf(a, "flat-rating") * HP2W;
 906     TurbineEngine* eng = new TurbineEngine(power, omega, alt, flatRating);
 907
 908     if(a->hasAttribute("n2-low-idle"))
 909         eng->setN2Range(attrf(a, "n2-low-idle"), attrf(a, "n2-high-idle"),
 910                         attrf(a, "n2-max"));
 911
 912     // Nasty units conversion: lbs/hr per hp -> kg/s per watt
 913     if(a->hasAttribute("bsfc"))
 914         eng->setFuelConsumption(attrf(a, "bsfc") * (LBS2KG/(3600*HP2W)));
 915
 916     ((PropEngine*)_currObj)->setEngine(eng);
 917 }
 918
 919 void FGFDM::parsePropeller(XMLAttributes* a)
 920 {
 921     // Legacy Handling for the old engines syntax:
 922     PistonEngine* eng = 0;
 923     if(a->hasAttribute("eng-power")) {
 924         SG_LOG(SG_FLIGHT,SG_ALERT, "WARNING: "
 925                << "Legacy engine definition in YASim configuration file.  "
 926                << "Please fix.");
 927         float engP = attrf(a, "eng-power") * HP2W;
 928         float engS = attrf(a, "eng-rpm") * RPM2RAD;
 929         eng = new PistonEngine(engP, engS);
 930         if(a->hasAttribute("displacement"))
 931             eng->setDisplacement(attrf(a, "displacement") * CIN2CM);
 932         if(a->hasAttribute("compression"))
 933             eng->setCompression(attrf(a, "compression"));
 934         if(a->hasAttribute("turbo-mul")) {
 935             float mul = attrf(a, "turbo-mul");
 936             float mp = attrf(a, "wastegate-mp", 1e6) * INHG2PA;
 937             eng->setTurboParams(mul, mp);
 938         }
 939     }
 940
 941     // Now parse the actual propeller definition:
 942     float cg[3];
 943     cg[0] = attrf(a, "x");
 944     cg[1] = attrf(a, "y");
 945     cg[2] = attrf(a, "z");
 946     float mass = attrf(a, "mass") * LBS2KG;
 947     float moment = attrf(a, "moment");
 948     float radius = attrf(a, "radius");
 949     float speed = attrf(a, "cruise-speed") * KTS2MPS;
 950     float omega = attrf(a, "cruise-rpm") * RPM2RAD;
 951     float power = attrf(a, "cruise-power") * HP2W;
 952     float rho = Atmosphere::getStdDensity(attrf(a, "cruise-alt") * FT2M);
 953
 954     Propeller* prop = new Propeller(radius, speed, omega, rho, power);
 955     PropEngine* thruster = new PropEngine(prop, eng, moment);
 956     _airplane.addThruster(thruster, mass, cg);
 957
 958     // Set the stops (fine = minimum pitch, coarse = maximum pitch)
 959     float fine_stop = attrf(a, "fine-stop", 0.25f);
 960     float coarse_stop = attrf(a, "coarse-stop", 4.0f);
 961     prop->setStops(fine_stop, coarse_stop);
 962
 963     if(a->hasAttribute("takeoff-power")) {
 964         float power0 = attrf(a, "takeoff-power") * HP2W;
 965         float omega0 = attrf(a, "takeoff-rpm") * RPM2RAD;
 966         prop->setTakeoff(omega0, power0);
 967     }
 968
 969     if(a->hasAttribute("max-rpm")) {
 970         float max = attrf(a, "max-rpm") * RPM2RAD;
 971         float min = attrf(a, "min-rpm") * RPM2RAD;
 972         thruster->setVariableProp(min, max);
 973     }
 974
 975     if(attrb(a, "contra"))
 976         thruster->setContraPair(true);
 977
 978     if(a->hasAttribute("manual-pitch")) {
 979         prop->setManualPitch();
 980     }
 981
 982     thruster->setGearRatio(attrf(a, "gear-ratio", 1));
 983
 984     char buf[64];
 985     sprintf(buf, "/engines/engine[%d]", _nextEngine++);
 986     EngRec* er = new EngRec();
 987     er->eng = thruster;
 988     er->prefix = dup(buf);
 989     _thrusters.add(er);
 990
 991     _currObj = thruster;
 992 }
 993
 994 // Turns a string axis name into an integer for use by the
 995 // ControlMap.  Creates a new axis if this one hasn't been defined
 996 // yet.
 997 int FGFDM::parseAxis(const char* name)
 998 {
 999     for(int i=0; i<_axes.size(); i++) {
1000         AxisRec* a = (AxisRec*)_axes.get(i);
1001         if(eq(a->name, name))
1002             return a->handle;
1003     }
1004
1005     // Not there, make a new one.
1006     AxisRec* a = new AxisRec();
1007     a->name = dup(name);
1008     fgGetNode( a->name, true ); // make sure the property name exists
1009     a->handle = _airplane.getControlMap()->newInput();
1010     _axes.add(a);
1011     return a->handle;
1012 }
1013
1014 int FGFDM::parseOutput(const char* name)
1015 {
1016     if(eq(name, "THROTTLE"))  return ControlMap::THROTTLE;
1017     if(eq(name, "MIXTURE"))   return ControlMap::MIXTURE;
1018     if(eq(name, "CONDLEVER")) return ControlMap::CONDLEVER;
1019     if(eq(name, "STARTER"))   return ControlMap::STARTER;
1020     if(eq(name, "MAGNETOS"))  return ControlMap::MAGNETOS;
1021     if(eq(name, "ADVANCE"))   return ControlMap::ADVANCE;
1022     if(eq(name, "REHEAT"))    return ControlMap::REHEAT;
1023     if(eq(name, "BOOST"))     return ControlMap::BOOST;
1024     if(eq(name, "VECTOR"))    return ControlMap::VECTOR;
1025     if(eq(name, "PROP"))      return ControlMap::PROP;
1026     if(eq(name, "BRAKE"))     return ControlMap::BRAKE;
1027     if(eq(name, "STEER"))     return ControlMap::STEER;
1028     if(eq(name, "EXTEND"))    return ControlMap::EXTEND;
1029     if(eq(name, "HEXTEND"))   return ControlMap::HEXTEND;
1030     if(eq(name, "LEXTEND"))   return ControlMap::LEXTEND;
1031         if(eq(name, "LACCEL"))    return ControlMap::LACCEL;
1032     if(eq(name, "INCIDENCE")) return ControlMap::INCIDENCE;
1033     if(eq(name, "FLAP0"))     return ControlMap::FLAP0;
1034     if(eq(name, "FLAP0EFFECTIVENESS"))   return ControlMap::FLAP0EFFECTIVENESS;
1035     if(eq(name, "FLAP1"))     return ControlMap::FLAP1;
1036     if(eq(name, "FLAP1EFFECTIVENESS"))   return ControlMap::FLAP1EFFECTIVENESS;
1037     if(eq(name, "SLAT"))      return ControlMap::SLAT;
1038     if(eq(name, "SPOILER"))   return ControlMap::SPOILER;
1039     if(eq(name, "CASTERING")) return ControlMap::CASTERING;
1040     if(eq(name, "PROPPITCH")) return ControlMap::PROPPITCH;
1041     if(eq(name, "PROPFEATHER")) return ControlMap::PROPFEATHER;
1042     if(eq(name, "COLLECTIVE")) return ControlMap::COLLECTIVE;
1043     if(eq(name, "CYCLICAIL")) return ControlMap::CYCLICAIL;
1044     if(eq(name, "CYCLICELE")) return ControlMap::CYCLICELE;
1045     if(eq(name, "TILTROLL")) return ControlMap::TILTROLL;
1046     if(eq(name, "TILTPITCH")) return ControlMap::TILTPITCH;
1047     if(eq(name, "TILTYAW")) return ControlMap::TILTYAW;
1048     if(eq(name, "ROTORGEARENGINEON")) return ControlMap::ROTORENGINEON;
1049     if(eq(name, "ROTORBRAKE")) return ControlMap::ROTORBRAKE;
1050     if(eq(name, "ROTORENGINEMAXRELTORQUE"))
1051         return ControlMap::ROTORENGINEMAXRELTORQUE;
1052     if(eq(name, "ROTORRELTARGET")) return ControlMap::ROTORRELTARGET;
1053     if(eq(name, "ROTORBALANCE")) return ControlMap::ROTORBALANCE;
1054     if(eq(name, "REVERSE_THRUST")) return ControlMap::REVERSE_THRUST;
1055     if(eq(name, "WASTEGATE")) return ControlMap::WASTEGATE;
1056     if(eq(name, "WINCHRELSPEED")) return ControlMap::WINCHRELSPEED;
1057     if(eq(name, "HITCHOPEN")) return ControlMap::HITCHOPEN;
1058     if(eq(name, "PLACEWINCH")) return ControlMap::PLACEWINCH;
1059     if(eq(name, "FINDAITOW")) return ControlMap::FINDAITOW;
1060
1061     SG_LOG(SG_FLIGHT,SG_ALERT,"Unrecognized control type '"
1062            << name << "' in YASim aircraft description.");
1063     exit(1);
1064
1065 }
1066
1067 void FGFDM::parseWeight(XMLAttributes* a)
1068 {
1069     WeightRec* wr = new WeightRec();
1070
1071     float v[3];
1072     v[0] = attrf(a, "x");
1073     v[1] = attrf(a, "y");
1074     v[2] = attrf(a, "z");
1075
1076     wr->prop = dup(a->getValue("mass-prop"));
1077     wr->size = attrf(a, "size", 0);
1078     wr->handle = _airplane.addWeight(v, wr->size);
1079
1080     _weights.add(wr);
1081 }
1082
1083 bool FGFDM::eq(const char* a, const char* b)
1084 {
1085     // Figure it out for yourself. :)
1086     while(*a && *b && *a == *b) { a++; b++; }
1087     return !(*a || *b);
1088 }
1089
1090 char* FGFDM::dup(const char* s)
1091 {
1092     int len=0;
1093     while(s[len++]);
1094     char* s2 = new char[len+1];
1095     char* p = s2;
1096     while((*p++ = *s++));
1097     s2[len] = 0;
1098     return s2;
1099 }
1100
1101 int FGFDM::attri(XMLAttributes* atts, const char* attr)
1102 {
1103     if(!atts->hasAttribute(attr)) {
1104         SG_LOG(SG_FLIGHT,SG_ALERT,"Missing '" << attr <<
1105                "' in YASim aircraft description");
1106         exit(1);
1107     }
1108     return attri(atts, attr, 0);
1109 }
1110
1111 int FGFDM::attri(XMLAttributes* atts, const char* attr, int def)
1112 {
1113     const char* val = atts->getValue(attr);
1114     if(val == 0) return def;
1115     else         return atol(val);
1116 }
1117
1118 float FGFDM::attrf(XMLAttributes* atts, const char* attr)
1119 {
1120     if(!atts->hasAttribute(attr)) {
1121         SG_LOG(SG_FLIGHT,SG_ALERT,"Missing '" << attr <<
1122                "' in YASim aircraft description");
1123         exit(1);
1124     }
1125     return attrf(atts, attr, 0);
1126 }
1127
1128 float FGFDM::attrf(XMLAttributes* atts, const char* attr, float def)
1129 {
1130     const char* val = atts->getValue(attr);
1131     if(val == 0) return def;
1132     else         return (float)atof(val);
1133 }
1134
1135 double FGFDM::attrd(XMLAttributes* atts, const char* attr)
1136 {
1137     if(!atts->hasAttribute(attr)) {
1138         SG_LOG(SG_FLIGHT,SG_ALERT,"Missing '" << attr <<
1139                "' in YASim aircraft description");
1140         exit(1);
1141     }
1142     return attrd(atts, attr, 0);
1143 }
1144
1145 double FGFDM::attrd(XMLAttributes* atts, const char* attr, double def)
1146 {
1147     const char* val = atts->getValue(attr);
1148     if(val == 0) return def;
1149     else         return atof(val);
1150 }
1151
1152 // ACK: the dreaded ambiguous string boolean.  Remind me to shoot Maik
1153 // when I have a chance. :).  Unless you have a parser that can check
1154 // symbol constants (we don't), this kind of coding is just a Bad
1155 // Idea.  This implementation, for example, silently returns a boolean
1156 // falsehood for values of "1", "yes", "True", and "TRUE".  Which is
1157 // especially annoying preexisting boolean attributes in the same
1158 // parser want to see "1" and will choke on a "true"...
1159 //
1160 // Unfortunately, this usage creeped into existing configuration files
1161 // while I wasn't active, and it's going to be hard to remove.  Issue
1162 // a warning to nag people into changing their ways for now...
1163 bool FGFDM::attrb(XMLAttributes* atts, const char* attr)
1164 {
1165     const char* val = atts->getValue(attr);
1166     if(val == 0) return false;
1167
1168     if(eq(val,"true")) {
1169         SG_LOG(SG_FLIGHT, SG_ALERT, "Warning: " <<
1170                "deprecated 'true' boolean in YASim configuration file.  " <<
1171                "Use numeric booleans (attribute=\"1\") instead");
1172         return true;
1173     }
1174     return attri(atts, attr, 0) ? true : false;
1175 }
1176
1177 }; // namespace yasim