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);
61 // FIXME: who owns these things? Need a policy
64 void Model::getThrust(float* out)
67 out[0] = out[1] = out[2] = 0;
69 for(i=0; i<_thrusters.size(); i++) {
70 Thruster* t = (Thruster*)_thrusters.get(i);
72 Math::add3(tmp, out, out);
76 void Model::initIteration()
78 // Precompute torque and angular momentum for the thrusters
81 _gyro[i] = _torque[i] = 0;
82 for(i=0; i<_thrusters.size(); i++) {
83 Thruster* t = (Thruster*)_thrusters.get(i);
85 // Get the wind velocity at the thruster location
88 localWind(pos, _s, v);
91 t->setAir(_pressure, _temp, _rho);
92 t->integrate(_integrator.getInterval());
95 Math::add3(v, _torque, _torque);
98 Math::add3(v, _gyro, _gyro);
101 // Displace the turbulence coordinates according to the local wind.
104 Math::mul3(_integrator.getInterval(), _wind, toff);
109 // FIXME: This method looks to me like it's doing *integration*, not
110 // initialization. Integration code should ideally go into
111 // calcForces. Only very "unstiff" problems can be solved well like
112 // this (see the engine code for an example); I don't know if rotor
113 // dynamics qualify or not.
115 void Model::initRotorIteration()
118 float dt = _integrator.getInterval();
120 Math::vmul33(_s->orient, _s->rot, lrot);
121 Math::mul3(dt,lrot,lrot);
122 for(i=0; i<_rotors.size(); i++) {
123 Rotor* r = (Rotor*)_rotors.get(i);
124 r->inititeration(dt);
126 for(i=0; i<_rotorparts.size(); i++) {
127 Rotorpart* rp = (Rotorpart*)_rotorparts.get(i);
128 rp->inititeration(dt,lrot);
130 for(i=0; i<_rotorblades.size(); i++) {
131 Rotorblade* rp = (Rotorblade*)_rotorblades.get(i);
132 rp->inititeration(dt,lrot);
136 void Model::iterate()
139 initRotorIteration();
140 _body.recalc(); // FIXME: amortize this, somehow
141 _integrator.calcNewInterval();
144 bool Model::isCrashed()
149 void Model::setCrashed(bool crashed)
154 float Model::getAGL()
159 State* Model::getState()
164 void Model::setState(State* s)
166 _integrator.setState(s);
167 _s = _integrator.getState();
170 RigidBody* Model::getBody()
175 Integrator* Model::getIntegrator()
180 Surface* Model::getSurface(int handle)
182 return (Surface*)_surfaces.get(handle);
185 Rotorpart* Model::getRotorpart(int handle)
187 return (Rotorpart*)_rotorparts.get(handle);
189 Rotorblade* Model::getRotorblade(int handle)
191 return (Rotorblade*)_rotorblades.get(handle);
193 Rotor* Model::getRotor(int handle)
195 return (Rotor*)_rotors.get(handle);
198 int Model::addThruster(Thruster* t)
200 return _thrusters.add(t);
203 int Model::numThrusters()
205 return _thrusters.size();
208 Thruster* Model::getThruster(int handle)
210 return (Thruster*)_thrusters.get(handle);
213 void Model::setThruster(int handle, Thruster* t)
215 _thrusters.set(handle, t);
218 int Model::addSurface(Surface* surf)
220 return _surfaces.add(surf);
223 int Model::addRotorpart(Rotorpart* rpart)
225 return _rotorparts.add(rpart);
227 int Model::addRotorblade(Rotorblade* rblade)
229 return _rotorblades.add(rblade);
231 int Model::addRotor(Rotor* r)
233 return _rotors.add(r);
236 int Model::addGear(Gear* gear)
238 return _gears.add(gear);
241 void Model::setGroundEffect(float* pos, float span, float mul)
243 Math::set3(pos, _wingCenter);
244 _groundEffectSpan = span;
248 // The first three elements are a unit vector pointing from the global
249 // origin to the plane, the final element is the distance from the
250 // origin (the radius of the earth, in most implementations). So
251 // (v dot _ground)-_ground[3] gives the distance AGL.
252 void Model::setGroundPlane(double* planeNormal, double fromOrigin)
255 for(i=0; i<3; i++) _ground[i] = planeNormal[i];
256 _ground[3] = fromOrigin;
259 void Model::setAir(float pressure, float temp, float density)
261 _pressure = pressure;
266 void Model::setWind(float* wind)
268 Math::set3(wind, _wind);
271 void Model::calcForces(State* s)
273 // Add in the pre-computed stuff. These values aren't part of the
274 // Runge-Kutta integration (they don't depend on position or
275 // velocity), and are therefore constant across the four calls to
276 // calcForces. They get computed before we begin the integration
278 _body.setGyro(_gyro);
279 _body.addTorque(_torque);
281 for(i=0; i<_thrusters.size(); i++) {
282 Thruster* t = (Thruster*)_thrusters.get(i);
283 float thrust[3], pos[3];
284 t->getThrust(thrust);
286 _body.addForce(pos, thrust);
289 // Gravity, convert to a force, then to local coordinates
291 Glue::geodUp(s->pos, grav);
292 Math::mul3(-9.8f * _body.getTotalMass(), grav, grav);
293 Math::vmul33(s->orient, grav, grav);
294 _body.addForce(grav);
296 // Do each surface, remembering that the local velocity at each
297 // point is different due to rotation.
299 faero[0] = faero[1] = faero[2] = 0;
300 for(i=0; i<_surfaces.size(); i++) {
301 Surface* sf = (Surface*)_surfaces.get(i);
303 // Vsurf = wind - velocity + (rot cross (cg - pos))
305 sf->getPosition(pos);
306 localWind(pos, s, vs);
308 float force[3], torque[3];
309 sf->calcForce(vs, _rho, force, torque);
310 Math::add3(faero, force, faero);
312 _body.addForce(pos, force);
313 _body.addTorque(torque);
315 for(i=0; i<_rotorparts.size(); i++) {
316 Rotorpart* sf = (Rotorpart*)_rotorparts.get(i);
318 // Vsurf = wind - velocity + (rot cross (cg - pos))
320 sf->getPosition(pos);
321 localWind(pos, s, vs);
323 float force[3], torque[3];
324 sf->calcForce(vs, _rho, force, torque);
325 //Math::add3(faero, force, faero);
327 sf->getPositionForceAttac(pos);
329 _body.addForce(pos, force);
330 _body.addTorque(torque);
332 for(i=0; i<_rotorblades.size(); i++) {
333 Rotorblade* sf = (Rotorblade*)_rotorblades.get(i);
335 // Vsurf = wind - velocity + (rot cross (cg - pos))
337 sf->getPosition(pos);
338 localWind(pos, s, vs);
340 float force[3], torque[3];
341 sf->calcForce(vs, _rho, force, torque);
342 //Math::add3(faero, force, faero);
344 sf->getPositionForceAttac(pos);
346 _body.addForce(pos, force);
347 _body.addTorque(torque);
350 // Get a ground plane in local coordinates. The first three
351 // elements are the normal vector, the final one is the distance
352 // from the local origin along that vector to the ground plane
353 // (negative for objects "above" the ground)
355 ground[3] = localGround(s, ground);
357 // Account for ground effect by multiplying the vertical force
358 // component by an amount linear with the fraction of the wingspan
360 float dist = ground[3] - Math::dot3(ground, _wingCenter);
361 if(dist > 0 && dist < _groundEffectSpan) {
362 float fz = Math::dot3(faero, ground);
363 fz *= (_groundEffectSpan - dist) / _groundEffectSpan;
365 Math::mul3(fz, ground, faero);
366 _body.addForce(faero);
369 // Convert the velocity and rotation vectors to local coordinates
370 float lrot[3], lv[3];
371 Math::vmul33(s->orient, s->rot, lrot);
372 Math::vmul33(s->orient, s->v, lv);
375 for(i=0; i<_gears.size(); i++) {
376 float force[3], contact[3];
377 Gear* g = (Gear*)_gears.get(i);
378 g->calcForce(&_body, lv, lrot, ground);
379 g->getForce(force, contact);
380 _body.addForce(contact, force);
384 void Model::newState(State* s)
388 // Some simple collision detection
390 float ground[4], pos[3], cmpr[3];
391 ground[3] = localGround(s, ground);
393 for(i=0; i<_gears.size(); i++) {
394 Gear* g = (Gear*)_gears.get(i);
396 // Get the point of ground contact
398 g->getCompression(cmpr);
399 Math::mul3(g->getCompressFraction(), cmpr, cmpr);
400 Math::add3(cmpr, pos, pos);
401 float dist = ground[3] - Math::dot3(pos, ground);
403 // Find the lowest one
408 if(_agl < -1) // Allow for some integration slop
412 // Returns a unit "down" vector for the ground in out, and the
413 // distance from the local origin to the ground as the return value.
414 // So for a given position V, "dist - (V dot out)" will be the height
416 float Model::localGround(State* s, float* out)
418 // Get the ground's "down" vector, this can be in floats, because
419 // we don't need positioning accuracy. The direction has plenty
420 // of accuracy after truncation.
421 out[0] = -(float)_ground[0];
422 out[1] = -(float)_ground[1];
423 out[2] = -(float)_ground[2];
424 Math::vmul33(s->orient, out, out);
426 // The distance from the ground to the Aircraft's origin:
427 double dist = (s->pos[0]*_ground[0]
428 + s->pos[1]*_ground[1]
429 + s->pos[2]*_ground[2] - _ground[3]);
434 // Calculates the airflow direction at the given point and for the
435 // specified aircraft velocity.
436 void Model::localWind(float* pos, State* s, float* out)
438 float tmp[3], lwind[3], lrot[3], lv[3];
440 // Get a global coordinate for our local position, and calculate
442 // FIXME: modify turbulence for altitude, attenuating the vertical
443 // component near the ground.
446 Math::tmul33(s->orient, pos, tmp);
447 for(int i=0; i<3; i++) gpos[i] = s->pos[i] + tmp[i];
448 _turb->getTurbulence(gpos, lwind);
449 Math::add3(_wind, lwind, lwind);
451 Math::set3(_wind, lwind);
454 // Convert to local coordinates
455 Math::vmul33(s->orient, lwind, lwind);
456 Math::vmul33(s->orient, s->rot, lrot);
457 Math::vmul33(s->orient, s->v, lv);
459 _body.pointVelocity(pos, lrot, out); // rotational velocity
460 Math::mul3(-1, out, out); // (negated)
461 Math::add3(lwind, out, out); // + wind
462 Math::sub3(out, lv, out); // - velocity
465 }; // namespace yasim