#include #include #include
#include "Jet.hpp" #include "Gear.hpp" #include "Atmosphere.hpp" #include "PropEngine.hpp" #include "Propeller.hpp" #include "PistonEngine.hpp" #include "FGFDM.hpp" namespace yasim { // Some conversion factors static const float KTS2MPS = 0.514444444444; static const float FT2M = 0.3048; static const float DEG2RAD = 0.0174532925199; static const float RPM2RAD = 0.10471975512; static const float LBS2N = 4.44822; static const float LBS2KG = 0.45359237; static const float CM2GALS = 264.172037284; static const float HP2W = 745.700; // Stubs, so that this can be compiled without the FlightGear // binary. What's the best way to handle this? // float fgGetFloat(char* name, float def) { return 0; } // void fgSetFloat(char* name, float val) {} FGFDM::FGFDM() { _nextEngine = 0; } FGFDM::~FGFDM() { for(int i=0; i<_axes.size(); i++) { AxisRec* a = (AxisRec*)_axes.get(i); delete[] a->name; delete a; } for(int i=0; i<_pistons.size(); i++) { EngRec* er = (EngRec*)_pistons.get(i); delete[] er->prefix; delete (PropEngine*)er->eng; delete er; } for(int i=0; i<_jets.size(); i++) { EngRec* er = (EngRec*)_pistons.get(i); delete[] er->prefix; delete (Jet*)er->eng; delete er; } for(int i=0; i<_weights.size(); i++) { WeightRec* wr = (WeightRec*)_weights.get(i); delete[] wr->prop; delete wr; } } void FGFDM::iterate(float dt) { getExternalInput(dt); _airplane.iterate(dt); setOutputProperties(); } Airplane* FGFDM::getAirplane() { return &_airplane; } void FGFDM::init() { // We don't want to use these ties (we set the values ourselves, // and this works only for the first piston engine anyway). fgUntie("/engines/engine[0]/rpm"); fgUntie("/engines/engine[0]/egt-degf"); fgUntie("/engines/engine[0]/cht-degf"); fgUntie("/engines/engine[0]/oil-temperature-degf"); fgUntie("/engines/engine[0]/mp-osi"); fgUntie("/engines/engine[0]/fuel-flow-gph"); fgUntie("/engines/engine[0]/running"); fgUntie("/engines/engine[0]/cranking"); fgUntie("/consumables/fuel/tank[0]/level-gal_us"); fgUntie("/consumables/fuel/tank[1]/level-gal_us"); // Set these to sane values. We don't support engine start yet. fgSetBool("/engines/engine[0]/running", true); fgSetBool("/engines/engine[0]/cranking", false); // Allows the user to start with something other than full fuel _airplane.setFuelFraction(fgGetFloat("/yasim/fuel-fraction", 1)); // This has a nasty habit of being false at startup. That's not // good. fgSetBool("/controls/gear-down", true); } // Not the worlds safest parser. But it's short & sweet. void FGFDM::startElement(const char* name, const XMLAttributes &atts) { XMLAttributes* a = (XMLAttributes*)&atts; float v[3]; char buf[64]; if(eq(name, "airplane")) { _airplane.setWeight(attrf(a, "mass") * LBS2KG); } else if(eq(name, "approach")) { float spd = attrf(a, "speed") * KTS2MPS; float alt = attrf(a, "alt", 0) * FT2M; float aoa = attrf(a, "aoa", 0) * DEG2RAD; _airplane.setApproach(spd, alt, aoa); _cruiseCurr = false; } else if(eq(name, "cruise")) { float spd = attrf(a, "speed") * KTS2MPS; float alt = attrf(a, "alt") * FT2M; _airplane.setCruise(spd, alt); _cruiseCurr = true; } else if(eq(name, "cockpit")) { v[0] = attrf(a, "x"); v[1] = attrf(a, "y"); v[2] = attrf(a, "z"); _airplane.setPilotPos(v); } else if(eq(name, "wing")) { _airplane.setWing(parseWing(a, name)); } else if(eq(name, "hstab")) { _airplane.setTail(parseWing(a, name)); } else if(eq(name, "vstab")) { _airplane.addVStab(parseWing(a, name)); } else if(eq(name, "propeller")) { parsePropeller(a); } else if(eq(name, "jet")) { Jet* j = new Jet(); _currObj = j; v[0] = attrf(a, "x"); v[1] = attrf(a, "y"); v[2] = attrf(a, "z"); float mass = attrf(a, "mass") * LBS2KG; j->setDryThrust(attrf(a, "thrust") * LBS2N); j->setPosition(v); _airplane.addThruster(j, mass, v); sprintf(buf, "/engines/engine[%d]", _nextEngine++); EngRec* er = new EngRec(); er->eng = j; er->prefix = dup(buf); _jets.add(er); } else if(eq(name, "gear")) { Gear* g = new Gear(); _currObj = g; v[0] = attrf(a, "x"); v[1] = attrf(a, "y"); v[2] = attrf(a, "z"); g->setPosition(v); v[0] = 0; v[1] = 0; v[2] = attrf(a, "compression", 1); g->setCompression(v); g->setStaticFriction(attrf(a, "sfric", 0.8)); g->setDynamicFriction(attrf(a, "dfric", 0.7)); float transitionTime = attrf(a, "retract-time", 0); _airplane.addGear(g, transitionTime); } else if(eq(name, "fuselage")) { float b[3]; v[0] = attrf(a, "ax"); v[1] = attrf(a, "ay"); v[2] = attrf(a, "az"); b[0] = attrf(a, "bx"); b[1] = attrf(a, "by"); b[2] = attrf(a, "bz"); _airplane.addFuselage(v, b, attrf(a, "width")); } else if(eq(name, "tank")) { v[0] = attrf(a, "x"); v[1] = attrf(a, "y"); v[2] = attrf(a, "z"); float density = 6.0; // gasoline, in lbs/gal if(a->hasAttribute("jet")) density = 6.72; density *= LBS2KG/CM2GALS; _airplane.addTank(v, attrf(a, "capacity") * LBS2KG, density); } else if(eq(name, "ballast")) { v[0] = attrf(a, "x"); v[1] = attrf(a, "y"); v[2] = attrf(a, "z"); _airplane.addBallast(v, attrf(a, "mass") * LBS2KG); } else if(eq(name, "weight")) { parseWeight(a); } else if(eq(name, "stall")) { Wing* w = (Wing*)_currObj; w->setStall(attrf(a, "aoa") * DEG2RAD); w->setStallWidth(attrf(a, "width", 2) * DEG2RAD); w->setStallPeak(attrf(a, "peak", 1.5)); } else if(eq(name, "flap0")) { ((Wing*)_currObj)->setFlap0(attrf(a, "start"), attrf(a, "end"), attrf(a, "lift"), attrf(a, "drag")); } else if(eq(name, "flap1")) { ((Wing*)_currObj)->setFlap1(attrf(a, "start"), attrf(a, "end"), attrf(a, "lift"), attrf(a, "drag")); } else if(eq(name, "slat")) { ((Wing*)_currObj)->setSlat(attrf(a, "start"), attrf(a, "end"), attrf(a, "aoa"), attrf(a, "drag")); } else if(eq(name, "spoiler")) { ((Wing*)_currObj)->setSpoiler(attrf(a, "start"), attrf(a, "end"), attrf(a, "lift"), attrf(a, "drag")); } else if(eq(name, "actionpt")) { v[0] = attrf(a, "x"); v[1] = attrf(a, "y"); v[2] = attrf(a, "z"); ((Thruster*)_currObj)->setPosition(v); } else if(eq(name, "dir")) { v[0] = attrf(a, "x"); v[1] = attrf(a, "y"); v[2] = attrf(a, "z"); ((Thruster*)_currObj)->setDirection(v); } else if(eq(name, "control")) { const char* axis = a->getValue("axis"); if(a->hasAttribute("output")) { // assert: output type must match _currObj type! const char* output = a->getValue("output"); int opt = 0; opt |= a->hasAttribute("split") ? ControlMap::OPT_SPLIT : 0; opt |= a->hasAttribute("invert") ? ControlMap::OPT_INVERT : 0; opt |= a->hasAttribute("square") ? ControlMap::OPT_SQUARE : 0; _airplane.getControlMap()->addMapping(parseAxis(axis), parseOutput(output), _currObj, opt); } else { // assert: must be under a "cruise" or "approach" tag float value = attrf(a, "value", 0); if(_cruiseCurr) _airplane.addCruiseControl(parseAxis(axis), value); else _airplane.addApproachControl(parseAxis(axis), value); } } else { *(int*)0=0; // unexpected tag, boom } } void FGFDM::getExternalInput(float dt) { // The control axes ControlMap* cm = _airplane.getControlMap(); cm->reset(); for(int i=0; i<_axes.size(); i++) { AxisRec* a = (AxisRec*)_axes.get(i); float val = fgGetFloat(a->name, 0); cm->setInput(a->handle, val); } cm->applyControls(); // Weights for(int i=0; i<_weights.size(); i++) { WeightRec* wr = (WeightRec*)_weights.get(i); _airplane.setWeight(wr->handle, fgGetFloat(wr->prop)); } // Gear state _airplane.setGearState(fgGetBool("/controls/gear-down"), dt); } void FGFDM::setOutputProperties() { char buf[256]; for(int i=0; i<_airplane.numTanks(); i++) { sprintf(buf, "/consumables/fuel/tank[%d]/level-gal_us", i); fgSetFloat(buf, CM2GALS*_airplane.getFuel(i)/_airplane.getFuelDensity(i)); } for(int i=0; i<_pistons.size(); i++) { EngRec* er = (EngRec*)_pistons.get(i); PropEngine* p = (PropEngine*)er->eng; sprintf(buf, "%s/rpm", er->prefix); fgSetFloat(buf, p->getOmega() * (30/3.15149265358979)); sprintf(buf, "%s/fuel-flow-gph", er->prefix); fgSetFloat(buf, p->getFuelFlow() * (3600*2.2/5)); // FIXME, wrong } for(int i=0; i<_jets.size(); i++) { EngRec* er = (EngRec*)_jets.get(i); Jet* j = (Jet*)er->eng; sprintf(buf, "%s/fuel-flow-gph", er->prefix); fgSetFloat(buf, j->getFuelFlow() * (3600*2.2/6)); // FIXME, wrong } } Wing* FGFDM::parseWing(XMLAttributes* a, const char* type) { Wing* w = new Wing(); float defDihed = 0; if(eq(type, "vstab")) defDihed = 90; else w->setMirror(true); float pos[3]; pos[0] = attrf(a, "x"); pos[1] = attrf(a, "y"); pos[2] = attrf(a, "z"); w->setBase(pos); w->setLength(attrf(a, "length")); w->setChord(attrf(a, "chord")); w->setSweep(attrf(a, "sweep", 0) * DEG2RAD); w->setTaper(attrf(a, "taper", 1)); w->setDihedral(attrf(a, "dihedral", defDihed) * DEG2RAD); w->setCamber(attrf(a, "camber", 0)); w->setIncidence(attrf(a, "incidence", 0) * DEG2RAD); float effect = attrf(a, "effectiveness", 1); w->setDragScale(w->getDragScale()*effect); _currObj = w; return w; } void FGFDM::parsePropeller(XMLAttributes* a) { float cg[3]; cg[0] = attrf(a, "x"); cg[1] = attrf(a, "y"); cg[2] = attrf(a, "z"); float mass = attrf(a, "mass") * LBS2KG; float moment = attrf(a, "moment"); float radius = attrf(a, "radius"); float speed = attrf(a, "cruise-speed") * KTS2MPS; float omega = attrf(a, "cruise-rpm") * RPM2RAD; float rho = Atmosphere::getStdDensity(attrf(a, "alt") * FT2M); float power = attrf(a, "takeoff-power") * HP2W; float omega0 = attrf(a, "takeoff-rpm") * RPM2RAD; // FIXME: this is a hack. Find a better way to ask the engine how // much power it can produce under cruise conditions. float cruisePower = (power * (rho/Atmosphere::getStdDensity(0)) * (omega/omega0)); Propeller* prop = new Propeller(radius, speed, omega, rho, cruisePower, omega0, power); PistonEngine* eng = new PistonEngine(power, omega0); PropEngine* thruster = new PropEngine(prop, eng, moment); _airplane.addThruster(thruster, mass, cg); char buf[64]; sprintf(buf, "/engines/engine[%d]", _nextEngine++); EngRec* er = new EngRec(); er->eng = thruster; er->prefix = dup(buf); _pistons.add(er); _currObj = thruster; } // Turns a string axis name into an integer for use by the // ControlMap. Creates a new axis if this one hasn't been defined // yet. int FGFDM::parseAxis(const char* name) { for(int i=0; i<_axes.size(); i++) { AxisRec* a = (AxisRec*)_axes.get(i); if(eq(a->name, name)) return a->handle; } // Not there, make a new one. AxisRec* a = new AxisRec(); a->name = dup(name); a->handle = _airplane.getControlMap()->newInput(); _axes.add(a); return a->handle; } int FGFDM::parseOutput(const char* name) { if(eq(name, "THROTTLE")) return ControlMap::THROTTLE; if(eq(name, "MIXTURE")) return ControlMap::MIXTURE; if(eq(name, "REHEAT")) return ControlMap::REHEAT; if(eq(name, "PROP")) return ControlMap::PROP; if(eq(name, "BRAKE")) return ControlMap::BRAKE; if(eq(name, "STEER")) return ControlMap::STEER; if(eq(name, "EXTEND")) return ControlMap::EXTEND; if(eq(name, "INCIDENCE")) return ControlMap::INCIDENCE; if(eq(name, "FLAP0")) return ControlMap::FLAP0; if(eq(name, "FLAP1")) return ControlMap::FLAP1; if(eq(name, "SLAT")) return ControlMap::SLAT; if(eq(name, "SPOILER")) return ControlMap::SPOILER; // error here... return -1; } void FGFDM::parseWeight(XMLAttributes* a) { WeightRec* wr = new WeightRec(); float v[3]; v[0] = attrf(a, "x"); v[1] = attrf(a, "y"); v[2] = attrf(a, "z"); wr->prop = dup(a->getValue("mass-prop")); wr->size = attrf(a, "size", 0); wr->handle = _airplane.addWeight(v, wr->size); _weights.add(wr); } bool FGFDM::eq(const char* a, const char* b) { // Figure it out for yourself. :) while(*a && *b && *a++ == *b++); return !(*a || *b); } char* FGFDM::dup(const char* s) { int len=0; while(s[len++]); char* s2 = new char[len+1]; char* p = s2; while((*p++ = *s++)); s2[len] = 0; return s2; } int FGFDM::attri(XMLAttributes* atts, char* attr) { if(!atts->hasAttribute(attr)) *(int*)0=0; // boom return attri(atts, attr, 0); } int FGFDM::attri(XMLAttributes* atts, char* attr, int def) { const char* val = atts->getValue(attr); if(val == 0) return def; else return atol(val); } float FGFDM::attrf(XMLAttributes* atts, char* attr) { if(!atts->hasAttribute(attr)) *(int*)0=0; // boom return attrf(atts, attr, 0); } float FGFDM::attrf(XMLAttributes* atts, char* attr, float def) { const char* val = atts->getValue(attr); if(val == 0) return def; else return (float)atof(val); } }; // namespace yasim