1 // native_fdm.cxx -- FGFS "Native" flight dynamics protocal class
3 // Written by Curtis Olson, started September 2001.
5 // Copyright (C) 2001 Curtis L. Olson - curt@flightgear.org
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
28 #include <simgear/debug/logstream.hxx>
29 #include <simgear/io/lowlevel.hxx> // endian tests
30 #include <simgear/io/iochannel.hxx>
31 #include <simgear/timing/sg_time.hxx>
33 #include <FDM/flight.hxx>
34 #include <Time/tmp.hxx>
35 #include <Main/fg_props.hxx>
36 #include <Main/globals.hxx>
37 #include <Scenery/scenery.hxx>
39 #include "native_fdm.hxx"
41 // FreeBSD works better with this included last ... (?)
42 #if defined(WIN32) && !defined(__CYGWIN__)
45 # include <netinet/in.h> // htonl() ntohl()
49 // The function htond is defined this way due to the way some
50 // processors and OSes treat floating point values. Some will raise
51 // an exception whenever a "bad" floating point value is loaded into a
52 // floating point register. Solaris is notorious for this, but then
53 // so is LynxOS on the PowerPC. By translating the data in place,
54 // there is no need to load a FP register with the "corruped" floating
55 // point value. By doing the BIG_ENDIAN test, I can optimize the
56 // routine for big-endian processors so it can be as efficient as
58 static void htond (double &x)
60 if ( sgIsLittleEndian() ) {
64 Double_Overlay = (int *) &x;
65 Holding_Buffer = Double_Overlay [0];
67 Double_Overlay [0] = htonl (Double_Overlay [1]);
68 Double_Overlay [1] = htonl (Holding_Buffer);
75 static void htonf (float &x)
77 if ( sgIsLittleEndian() ) {
81 Float_Overlay = (int *) &x;
82 Holding_Buffer = Float_Overlay [0];
84 Float_Overlay [0] = htonl (Holding_Buffer);
91 FGNativeFDM::FGNativeFDM() {
94 FGNativeFDM::~FGNativeFDM() {
98 // open hailing frequencies
99 bool FGNativeFDM::open() {
100 if ( is_enabled() ) {
101 SG_LOG( SG_IO, SG_ALERT, "This shouldn't happen, but the channel "
102 << "is already in use, ignoring" );
106 SGIOChannel *io = get_io_channel();
108 if ( ! io->open( get_direction() ) ) {
109 SG_LOG( SG_IO, SG_ALERT, "Error opening channel communication layer." );
115 // Is this really needed here ????
116 cur_fdm_state->_set_Sea_level_radius( SG_EQUATORIAL_RADIUS_FT );
122 void FGProps2NetFDM( FGNetFDM *net, bool net_byte_order ) {
125 // Version sanity checking
126 net->version = FG_NET_FDM_VERSION;
129 net->longitude = cur_fdm_state->get_Longitude();
130 net->latitude = cur_fdm_state->get_Latitude();
131 net->altitude = cur_fdm_state->get_Altitude() * SG_FEET_TO_METER;
132 net->agl = cur_fdm_state->get_Altitude_AGL() * SG_FEET_TO_METER;
133 net->phi = cur_fdm_state->get_Phi();
134 net->theta = cur_fdm_state->get_Theta();
135 net->psi = cur_fdm_state->get_Psi();
136 net->alpha = cur_fdm_state->get_Alpha();
137 net->beta = cur_fdm_state->get_Beta();
138 net->phidot = cur_fdm_state->get_Phi_dot_degps() * SG_DEGREES_TO_RADIANS;
139 net->thetadot = cur_fdm_state->get_Theta_dot_degps()
140 * SG_DEGREES_TO_RADIANS;
141 net->psidot = cur_fdm_state->get_Psi_dot_degps() * SG_DEGREES_TO_RADIANS;
143 net->vcas = cur_fdm_state->get_V_calibrated_kts();
144 net->climb_rate = cur_fdm_state->get_Climb_Rate();
146 net->v_north = cur_fdm_state->get_V_north();
147 net->v_east = cur_fdm_state->get_V_east();
148 net->v_down = cur_fdm_state->get_V_down();
149 net->v_wind_body_north = cur_fdm_state->get_uBody();
150 net->v_wind_body_east = cur_fdm_state->get_vBody();
151 net->v_wind_body_down = cur_fdm_state->get_wBody();
153 net->A_X_pilot = cur_fdm_state->get_A_X_pilot();
154 net->A_Y_pilot = cur_fdm_state->get_A_Y_pilot();
155 net->A_Z_pilot = cur_fdm_state->get_A_Z_pilot();
157 net->stall_warning = fgGetDouble("/sim/alarms/stall-warning", 0.0);
159 = fgGetDouble("/instrumentation/slip-skid-ball/indicated-slip-skid");
162 net->num_engines = FGNetFDM::FG_MAX_ENGINES;
163 for ( i = 0; i < net->num_engines; ++i ) {
164 SGPropertyNode *node = fgGetNode("engines/engine", i, true);
165 if ( node->getBoolValue( "running" ) ) {
166 net->eng_state[0] = 2;
167 } else if ( node->getBoolValue( "cranking" ) ) {
168 net->eng_state[0] = 1;
170 net->eng_state[0] = 0;
172 net->rpm[i] = node->getDoubleValue( "rpm" );
173 net->fuel_flow[i] = node->getDoubleValue( "fuel-flow-gph" );
174 net->EGT[i] = node->getDoubleValue( "egt-degf" );
175 // cout << "egt = " << aero->EGT << endl;
176 net->oil_temp[i] = node->getDoubleValue( "oil-temperature-degf" );
177 net->oil_px[i] = node->getDoubleValue( "oil-pressure-psi" );
181 net->num_tanks = FGNetFDM::FG_MAX_TANKS;
182 for ( i = 0; i < net->num_tanks; ++i ) {
183 SGPropertyNode *node = fgGetNode("/consumables/fuel/tank", i, true);
184 net->fuel_quantity[i] = node->getDoubleValue("level-gal_us");
188 net->num_wheels = FGNetFDM::FG_MAX_WHEELS;
189 for (i = 0; i < net->num_wheels; ++i ) {
190 SGPropertyNode *node = fgGetNode("/gear/gear", i, true);
191 net->wow[i] = node->getDoubleValue("wow");
192 net->gear_pos[i] = node->getDoubleValue("position-norm");
193 net->gear_steer[i] = node->getDoubleValue("steering-norm");
194 net->gear_compression[i] = node->getDoubleValue("compression-norm");
197 // the following really aren't used in this context
198 net->cur_time = globals->get_time_params()->get_cur_time();
199 net->warp = globals->get_warp();
200 net->visibility = fgGetDouble("/environment/visibility-m");
202 // Control surface positions
203 SGPropertyNode *node = fgGetNode("/surface-positions", true);
204 net->elevator = node->getDoubleValue( "elevator-pos-norm" );
205 net->elevator_trim_tab
206 = node->getDoubleValue( "elevator-trim-tab-pos-norm" );
207 net->flaps = node->getDoubleValue( "flap-pos-norm" );
208 net->left_aileron = node->getDoubleValue( "left-aileron-pos-norm" );
209 net->right_aileron = node->getDoubleValue( "right-aileron-pos-norm" );
210 net->rudder = node->getDoubleValue( "rudder-pos-norm" );
211 net->rudder = node->getDoubleValue( "nose-wheel-pos-norm" );
212 net->speedbrake = node->getDoubleValue( "speedbrake-pos-norm" );
213 net->spoilers = node->getDoubleValue( "spoilers-pos-norm" );
215 if ( net_byte_order ) {
216 // Convert the net buffer to network format
217 net->version = htonl(net->version);
219 htond(net->longitude);
220 htond(net->latitude);
221 htond(net->altitude);
230 htonf(net->thetadot);
233 htonf(net->climb_rate);
237 htonf(net->v_wind_body_north);
238 htonf(net->v_wind_body_east);
239 htonf(net->v_wind_body_down);
241 htonf(net->A_X_pilot);
242 htonf(net->A_Y_pilot);
243 htonf(net->A_Z_pilot);
245 htonf(net->stall_warning);
246 htonf(net->slip_deg);
248 for ( i = 0; i < net->num_engines; ++i ) {
249 net->eng_state[i] = htonl(net->eng_state[i]);
251 htonf(net->fuel_flow[i]);
253 htonf(net->oil_temp[i]);
254 htonf(net->oil_px[i]);
256 net->num_engines = htonl(net->num_engines);
258 for ( i = 0; i < net->num_tanks; ++i ) {
259 htonf(net->fuel_quantity[i]);
261 net->num_tanks = htonl(net->num_tanks);
263 for ( i = 0; i < net->num_wheels; ++i ) {
264 net->wow[i] = htonl(net->wow[i]);
265 htonf(net->gear_pos[i]);
266 htonf(net->gear_steer[i]);
267 htonf(net->gear_compression[i]);
269 net->num_wheels = htonl(net->num_wheels);
271 net->cur_time = htonl( net->cur_time );
272 net->warp = htonl( net->warp );
273 htonf(net->visibility);
275 htonf(net->elevator);
276 htonf(net->elevator_trim_tab);
278 htonf(net->left_aileron);
279 htonf(net->right_aileron);
281 htonf(net->nose_wheel);
282 htonf(net->speedbrake);
283 htonf(net->spoilers);
288 void FGNetFDM2Props( FGNetFDM *net, bool net_byte_order ) {
291 if ( net_byte_order ) {
292 // Convert to the net buffer from network format
293 net->version = ntohl(net->version);
295 htond(net->longitude);
296 htond(net->latitude);
297 htond(net->altitude);
306 htonf(net->thetadot);
309 htonf(net->climb_rate);
313 htonf(net->v_wind_body_north);
314 htonf(net->v_wind_body_east);
315 htonf(net->v_wind_body_down);
317 htonf(net->A_X_pilot);
318 htonf(net->A_Y_pilot);
319 htonf(net->A_Z_pilot);
321 htonf(net->stall_warning);
322 htonf(net->slip_deg);
324 net->num_engines = htonl(net->num_engines);
325 for ( i = 0; i < net->num_engines; ++i ) {
326 net->eng_state[i] = htonl(net->eng_state[i]);
328 htonf(net->fuel_flow[i]);
330 htonf(net->oil_temp[i]);
331 htonf(net->oil_px[i]);
334 net->num_tanks = htonl(net->num_tanks);
335 for ( i = 0; i < net->num_tanks; ++i ) {
336 htonf(net->fuel_quantity[i]);
339 net->num_wheels = htonl(net->num_wheels);
340 for ( i = 0; i < net->num_wheels; ++i ) {
341 net->wow[i] = htonl(net->wow[i]);
342 htonf(net->gear_pos[i]);
343 htonf(net->gear_steer[i]);
344 htonf(net->gear_compression[i]);
347 net->cur_time = ntohl(net->cur_time);
348 net->warp = ntohl(net->warp);
349 htonf(net->visibility);
351 htonf(net->elevator);
352 htonf(net->elevator_trim_tab);
354 htonf(net->left_aileron);
355 htonf(net->right_aileron);
357 htonf(net->nose_wheel);
358 htonf(net->speedbrake);
359 htonf(net->spoilers);
362 if ( net->version == FG_NET_FDM_VERSION ) {
363 // cout << "pos = " << net->longitude << " " << net->latitude << endl;
364 // cout << "sea level rad = " << cur_fdm_state->get_Sea_level_radius()
366 cur_fdm_state->_updateGeodeticPosition( net->latitude,
369 * SG_METER_TO_FEET );
370 if ( net->agl > -9000 ) {
371 cur_fdm_state->_set_Altitude_AGL( net->agl * SG_METER_TO_FEET );
374 = net->altitude - globals->get_scenery()->get_cur_elev();
375 cur_fdm_state->_set_Altitude_AGL( agl_m * SG_METER_TO_FEET );
377 cur_fdm_state->_set_Euler_Angles( net->phi,
380 cur_fdm_state->_set_Alpha( net->alpha );
381 cur_fdm_state->_set_Beta( net->beta );
382 cur_fdm_state->_set_Euler_Rates( net->phidot,
385 cur_fdm_state->_set_V_calibrated_kts( net->vcas );
386 cur_fdm_state->_set_Climb_Rate( net->climb_rate );
387 cur_fdm_state->_set_Velocities_Local( net->v_north,
390 cur_fdm_state->_set_Velocities_Wind_Body( net->v_wind_body_north,
391 net->v_wind_body_east,
392 net->v_wind_body_down );
394 cur_fdm_state->_set_Accels_Pilot_Body( net->A_X_pilot,
398 fgSetDouble( "/sim/alarms/stall-warning", net->stall_warning );
399 fgSetDouble( "/instrumentation/slip-skid-ball/indicated-slip-skid",
401 fgSetBool( "/instrumentation/slip-skid-ball/override", true );
403 for ( i = 0; i < net->num_engines; ++i ) {
404 SGPropertyNode *node = fgGetNode( "engines/engine", i, true );
406 // node->setBoolValue("running", t->isRunning());
407 // node->setBoolValue("cranking", t->isCranking());
409 // cout << net->eng_state[i] << endl;
410 if ( net->eng_state[i] == 0 ) {
411 node->setBoolValue( "cranking", false );
412 node->setBoolValue( "running", false );
413 } else if ( net->eng_state[i] == 1 ) {
414 node->setBoolValue( "cranking", true );
415 node->setBoolValue( "running", false );
416 } else if ( net->eng_state[i] == 2 ) {
417 node->setBoolValue( "cranking", false );
418 node->setBoolValue( "running", true );
421 node->setDoubleValue( "rpm", net->rpm[i] );
422 node->setDoubleValue( "fuel-flow-gph", net->fuel_flow[i] );
423 node->setDoubleValue( "egt-degf", net->EGT[i] );
424 node->setDoubleValue( "oil-temperature-degf", net->oil_temp[i] );
425 node->setDoubleValue( "oil-pressure-psi", net->oil_px[i] );
428 for (i = 0; i < net->num_tanks; ++i ) {
429 SGPropertyNode * node
430 = fgGetNode("/consumables/fuel/tank", i, true);
431 node->setDoubleValue("level-gal_us", net->fuel_quantity[i] );
434 for (i = 0; i < net->num_wheels; ++i ) {
435 SGPropertyNode * node = fgGetNode("/gear/gear", i, true);
436 node->setDoubleValue("wow", net->wow[i] );
437 node->setDoubleValue("position-norm", net->gear_pos[i] );
438 node->setDoubleValue("steering-norm", net->gear_steer[i] );
439 node->setDoubleValue("compression-norm", net->gear_compression[i] );
442 /* these are ignored for now ... */
444 if ( net->cur_time ) {
445 fgSetLong("/sim/time/cur-time-override", net->cur_time);
448 globals->set_warp( net->warp );
449 last_warp = net->warp;
452 SGPropertyNode *node = fgGetNode("/surface-positions", true);
453 node->setDoubleValue("elevator-pos-norm", net->elevator);
454 node->setDoubleValue("elevator-trim-tab-pos-norm",
455 net->elevator_trim_tab);
456 node->setDoubleValue("flap-pos-norm", net->flaps);
457 node->setDoubleValue("left-aileron-pos-norm", net->left_aileron);
458 node->setDoubleValue("right-aileron-pos-norm", net->right_aileron);
459 node->setDoubleValue("rudder-pos-norm", net->rudder);
460 node->setDoubleValue("nose-wheel-pos-norm", net->nose_wheel);
461 node->setDoubleValue("speedbrake-pos-norm", net->speedbrake);
462 node->setDoubleValue("spoilers-pos-norm", net->spoilers);
464 SG_LOG( SG_IO, SG_ALERT,
465 "Error: version mismatch in FGNetFDM2Props()" );
466 SG_LOG( SG_IO, SG_ALERT,
467 "\tread " << net->version << " need " << FG_NET_FDM_VERSION );
468 SG_LOG( SG_IO, SG_ALERT,
469 "\tNeeds to upgrade net_fdm.hxx and recompile." );
474 // process work for this port
475 bool FGNativeFDM::process() {
476 SGIOChannel *io = get_io_channel();
477 int length = sizeof(buf);
479 if ( get_direction() == SG_IO_OUT ) {
480 // cout << "size of cur_fdm_state = " << length << endl;
481 FGProps2NetFDM( &buf );
482 if ( ! io->write( (char *)(& buf), length ) ) {
483 SG_LOG( SG_IO, SG_ALERT, "Error writing data." );
486 } else if ( get_direction() == SG_IO_IN ) {
487 if ( io->get_type() == sgFileType ) {
488 if ( io->read( (char *)(& buf), length ) == length ) {
489 SG_LOG( SG_IO, SG_DEBUG, "Success reading data." );
490 FGNetFDM2Props( &buf );
494 result = io->read( (char *)(& buf), length );
495 while ( result == length ) {
496 if ( result == length ) {
497 SG_LOG( SG_IO, SG_DEBUG, " Success reading data." );
498 FGNetFDM2Props( &buf );
500 result = io->read( (char *)(& buf), length );
510 bool FGNativeFDM::close() {
511 SGIOChannel *io = get_io_channel();
513 set_enabled( false );
515 if ( ! io->close() ) {