1 #include "Atmosphere.hpp"
2 #include "Thruster.hpp"
4 #include "RigidBody.hpp"
5 #include "Integrator.hpp"
6 #include "Propeller.hpp"
7 #include "PistonEngine.hpp"
11 #include "Rotorpart.hpp"
12 #include "Rotorblade.hpp"
19 void printState(State* s)
22 Math::vmul33(tmp.orient, tmp.v, tmp.v);
23 Math::vmul33(tmp.orient, tmp.acc, tmp.acc);
24 Math::vmul33(tmp.orient, tmp.rot, tmp.rot);
25 Math::vmul33(tmp.orient, tmp.racc, tmp.racc);
27 printf("\nNEW STATE (LOCAL COORDS)\n");
28 printf("pos: %10.2f %10.2f %10.2f\n", tmp.pos[0], tmp.pos[1], tmp.pos[2]);
32 if(i != 0) printf(" ");
33 printf("%6.2f %6.2f %6.2f\n",
34 tmp.orient[3*i+0], tmp.orient[3*i+1], tmp.orient[3*i+2]);
36 printf("v: %6.2f %6.2f %6.2f\n", tmp.v[0], tmp.v[1], tmp.v[2]);
37 printf("acc: %6.2f %6.2f %6.2f\n", tmp.acc[0], tmp.acc[1], tmp.acc[2]);
38 printf("rot: %6.2f %6.2f %6.2f\n", tmp.rot[0], tmp.rot[1], tmp.rot[2]);
39 printf("rac: %6.2f %6.2f %6.2f\n", tmp.racc[0], tmp.racc[1], tmp.racc[2]);
46 for(i=0; i<3; i++) _wind[i] = 0;
48 _integrator.setBody(&_body);
49 _integrator.setEnvironment(this);
51 // Default value of 30 Hz
52 _integrator.setInterval(1.0f/30.0f);
60 // FIXME: who owns these things? Need a policy
63 void Model::getThrust(float* out)
66 out[0] = out[1] = out[2] = 0;
68 for(i=0; i<_thrusters.size(); i++) {
69 Thruster* t = (Thruster*)_thrusters.get(i);
71 Math::add3(tmp, out, out);
75 void Model::initIteration()
77 // Precompute torque and angular momentum for the thrusters
80 _gyro[i] = _torque[i] = 0;
81 for(i=0; i<_thrusters.size(); i++) {
82 Thruster* t = (Thruster*)_thrusters.get(i);
84 // Get the wind velocity at the thruster location
87 localWind(pos, _s, v);
90 t->setAir(_pressure, _temp, _rho);
91 t->integrate(_integrator.getInterval());
94 Math::add3(v, _torque, _torque);
97 Math::add3(v, _gyro, _gyro);
101 // FIXME: This method looks to me like it's doing *integration*, not
102 // initialization. Integration code should ideally go into
103 // calcForces. Only very "unstiff" problems can be solved well like
104 // this (see the engine code for an example); I don't know if rotor
105 // dynamics qualify or not.
107 void Model::initRotorIteration()
110 float dt = _integrator.getInterval();
112 Math::vmul33(_s->orient, _s->rot, lrot);
113 Math::mul3(dt,lrot,lrot);
114 for(i=0; i<_rotors.size(); i++) {
115 Rotor* r = (Rotor*)_rotors.get(i);
116 r->inititeration(dt);
118 for(i=0; i<_rotorparts.size(); i++) {
119 Rotorpart* rp = (Rotorpart*)_rotorparts.get(i);
120 rp->inititeration(dt,lrot);
122 for(i=0; i<_rotorblades.size(); i++) {
123 Rotorblade* rp = (Rotorblade*)_rotorblades.get(i);
124 rp->inititeration(dt,lrot);
128 void Model::iterate()
131 initRotorIteration();
132 _body.recalc(); // FIXME: amortize this, somehow
133 _integrator.calcNewInterval();
136 bool Model::isCrashed()
141 void Model::setCrashed(bool crashed)
146 float Model::getAGL()
151 State* Model::getState()
156 void Model::setState(State* s)
158 _integrator.setState(s);
159 _s = _integrator.getState();
162 RigidBody* Model::getBody()
167 Integrator* Model::getIntegrator()
172 Surface* Model::getSurface(int handle)
174 return (Surface*)_surfaces.get(handle);
177 Rotorpart* Model::getRotorpart(int handle)
179 return (Rotorpart*)_rotorparts.get(handle);
181 Rotorblade* Model::getRotorblade(int handle)
183 return (Rotorblade*)_rotorblades.get(handle);
185 Rotor* Model::getRotor(int handle)
187 return (Rotor*)_rotors.get(handle);
190 int Model::addThruster(Thruster* t)
192 return _thrusters.add(t);
195 int Model::numThrusters()
197 return _thrusters.size();
200 Thruster* Model::getThruster(int handle)
202 return (Thruster*)_thrusters.get(handle);
205 void Model::setThruster(int handle, Thruster* t)
207 _thrusters.set(handle, t);
210 int Model::addSurface(Surface* surf)
212 return _surfaces.add(surf);
215 int Model::addRotorpart(Rotorpart* rpart)
217 return _rotorparts.add(rpart);
219 int Model::addRotorblade(Rotorblade* rblade)
221 return _rotorblades.add(rblade);
223 int Model::addRotor(Rotor* r)
225 return _rotors.add(r);
228 int Model::addGear(Gear* gear)
230 return _gears.add(gear);
233 void Model::setGroundEffect(float* pos, float span, float mul)
235 Math::set3(pos, _wingCenter);
236 _groundEffectSpan = span;
240 // The first three elements are a unit vector pointing from the global
241 // origin to the plane, the final element is the distance from the
242 // origin (the radius of the earth, in most implementations). So
243 // (v dot _ground)-_ground[3] gives the distance AGL.
244 void Model::setGroundPlane(double* planeNormal, double fromOrigin)
247 for(i=0; i<3; i++) _ground[i] = planeNormal[i];
248 _ground[3] = fromOrigin;
251 void Model::setAir(float pressure, float temp, float density)
253 _pressure = pressure;
258 void Model::setWind(float* wind)
260 Math::set3(wind, _wind);
263 void Model::calcForces(State* s)
265 // Add in the pre-computed stuff. These values aren't part of the
266 // Runge-Kutta integration (they don't depend on position or
267 // velocity), and are therefore constant across the four calls to
268 // calcForces. They get computed before we begin the integration
270 _body.setGyro(_gyro);
271 _body.addTorque(_torque);
273 for(i=0; i<_thrusters.size(); i++) {
274 Thruster* t = (Thruster*)_thrusters.get(i);
275 float thrust[3], pos[3];
276 t->getThrust(thrust);
278 _body.addForce(pos, thrust);
281 // Gravity, convert to a force, then to local coordinates
283 Glue::geodUp(s->pos, grav);
284 Math::mul3(-9.8f * _body.getTotalMass(), grav, grav);
285 Math::vmul33(s->orient, grav, grav);
286 _body.addForce(grav);
288 // Do each surface, remembering that the local velocity at each
289 // point is different due to rotation.
291 faero[0] = faero[1] = faero[2] = 0;
292 for(i=0; i<_surfaces.size(); i++) {
293 Surface* sf = (Surface*)_surfaces.get(i);
295 // Vsurf = wind - velocity + (rot cross (cg - pos))
297 sf->getPosition(pos);
298 localWind(pos, s, vs);
300 float force[3], torque[3];
301 sf->calcForce(vs, _rho, force, torque);
302 Math::add3(faero, force, faero);
304 _body.addForce(pos, force);
305 _body.addTorque(torque);
307 for(i=0; i<_rotorparts.size(); i++) {
308 Rotorpart* sf = (Rotorpart*)_rotorparts.get(i);
310 // Vsurf = wind - velocity + (rot cross (cg - pos))
312 sf->getPosition(pos);
313 localWind(pos, s, vs);
315 float force[3], torque[3];
316 sf->calcForce(vs, _rho, force, torque);
317 //Math::add3(faero, force, faero);
319 sf->getPositionForceAttac(pos);
321 _body.addForce(pos, force);
322 _body.addTorque(torque);
324 for(i=0; i<_rotorblades.size(); i++) {
325 Rotorblade* sf = (Rotorblade*)_rotorblades.get(i);
327 // Vsurf = wind - velocity + (rot cross (cg - pos))
329 sf->getPosition(pos);
330 localWind(pos, s, vs);
332 float force[3], torque[3];
333 sf->calcForce(vs, _rho, force, torque);
334 //Math::add3(faero, force, faero);
336 sf->getPositionForceAttac(pos);
338 _body.addForce(pos, force);
339 _body.addTorque(torque);
342 // Get a ground plane in local coordinates. The first three
343 // elements are the normal vector, the final one is the distance
344 // from the local origin along that vector to the ground plane
345 // (negative for objects "above" the ground)
347 ground[3] = localGround(s, ground);
349 // Account for ground effect by multiplying the vertical force
350 // component by an amount linear with the fraction of the wingspan
352 float dist = ground[3] - Math::dot3(ground, _wingCenter);
353 if(dist > 0 && dist < _groundEffectSpan) {
354 float fz = Math::dot3(faero, ground);
355 fz *= (_groundEffectSpan - dist) / _groundEffectSpan;
357 Math::mul3(fz, ground, faero);
358 _body.addForce(faero);
361 // Convert the velocity and rotation vectors to local coordinates
362 float lrot[3], lv[3];
363 Math::vmul33(s->orient, s->rot, lrot);
364 Math::vmul33(s->orient, s->v, lv);
367 for(i=0; i<_gears.size(); i++) {
368 float force[3], contact[3];
369 Gear* g = (Gear*)_gears.get(i);
370 g->calcForce(&_body, lv, lrot, ground);
371 g->getForce(force, contact);
372 _body.addForce(contact, force);
376 void Model::newState(State* s)
380 // Some simple collision detection
382 float ground[4], pos[3], cmpr[3];
383 ground[3] = localGround(s, ground);
385 for(i=0; i<_gears.size(); i++) {
386 Gear* g = (Gear*)_gears.get(i);
388 // Get the point of ground contact
390 g->getCompression(cmpr);
391 Math::mul3(g->getCompressFraction(), cmpr, cmpr);
392 Math::add3(cmpr, pos, pos);
393 float dist = ground[3] - Math::dot3(pos, ground);
395 // Find the lowest one
400 if(_agl < -1) // Allow for some integration slop
404 // Returns a unit "down" vector for the ground in out, and the
405 // distance from the local origin to the ground as the return value.
406 // So for a given position V, "dist - (V dot out)" will be the height
408 float Model::localGround(State* s, float* out)
410 // Get the ground's "down" vector, this can be in floats, because
411 // we don't need positioning accuracy. The direction has plenty
412 // of accuracy after truncation.
413 out[0] = -(float)_ground[0];
414 out[1] = -(float)_ground[1];
415 out[2] = -(float)_ground[2];
416 Math::vmul33(s->orient, out, out);
418 // The distance from the ground to the Aircraft's origin:
419 double dist = (s->pos[0]*_ground[0]
420 + s->pos[1]*_ground[1]
421 + s->pos[2]*_ground[2] - _ground[3]);
426 // Calculates the airflow direction at the given point and for the
427 // specified aircraft velocity.
428 void Model::localWind(float* pos, State* s, float* out)
430 // Most of the input is in global coordinates. Fix that.
431 float lwind[3], lrot[3], lv[3];
432 Math::vmul33(s->orient, _wind, lwind);
433 Math::vmul33(s->orient, s->rot, lrot);
434 Math::vmul33(s->orient, s->v, lv);
436 _body.pointVelocity(pos, lrot, out); // rotational velocity
437 Math::mul3(-1, out, out); // (negated)
438 Math::add3(lwind, out, out); // + wind
439 Math::sub3(out, lv, out); // - velocity
442 }; // namespace yasim