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->phidot = cur_fdm_state->get_Phi_dot_degps() * SG_DEGREES_TO_RADIANS;
137 net->thetadot = cur_fdm_state->get_Theta_dot_degps()
138 * SG_DEGREES_TO_RADIANS;
139 net->psidot = cur_fdm_state->get_Psi_dot_degps() * SG_DEGREES_TO_RADIANS;
141 net->vcas = cur_fdm_state->get_V_calibrated_kts();
142 net->climb_rate = cur_fdm_state->get_Climb_Rate();
144 net->v_north = cur_fdm_state->get_V_north();
145 net->v_east = cur_fdm_state->get_V_east();
146 net->v_down = cur_fdm_state->get_V_down();
147 net->v_wind_body_north = cur_fdm_state->get_uBody();
148 net->v_wind_body_east = cur_fdm_state->get_vBody();
149 net->v_wind_body_down = cur_fdm_state->get_wBody();
150 net->stall_warning = fgGetDouble("/sim/alarms/stall-warning", 0.0);
152 net->A_X_pilot = cur_fdm_state->get_A_X_pilot();
153 net->A_Y_pilot = cur_fdm_state->get_A_Y_pilot();
154 net->A_Z_pilot = cur_fdm_state->get_A_Z_pilot();
157 net->num_engines = FGNetFDM::FG_MAX_ENGINES;
158 for ( i = 0; i < net->num_engines; ++i ) {
159 SGPropertyNode *node = fgGetNode("engines/engine", i, true);
160 if ( node->getBoolValue( "running" ) ) {
161 net->eng_state[0] = 2;
162 } else if ( node->getBoolValue( "cranking" ) ) {
163 net->eng_state[0] = 1;
165 net->eng_state[0] = 0;
167 net->rpm[i] = node->getDoubleValue( "rpm" );
168 net->fuel_flow[i] = node->getDoubleValue( "fuel-flow-gph" );
169 net->EGT[i] = node->getDoubleValue( "egt-degf" );
170 // cout << "egt = " << aero->EGT << endl;
171 net->oil_temp[i] = node->getDoubleValue( "oil-temperature-degf" );
172 net->oil_px[i] = node->getDoubleValue( "oil-pressure-psi" );
176 net->num_tanks = FGNetFDM::FG_MAX_TANKS;
177 for ( i = 0; i < net->num_tanks; ++i ) {
178 SGPropertyNode *node = fgGetNode("/consumables/fuel/tank", i, true);
179 net->fuel_quantity[i] = node->getDoubleValue("level-gal_us");
183 net->num_wheels = FGNetFDM::FG_MAX_WHEELS;
184 for (i = 0; i < net->num_wheels; ++i ) {
185 SGPropertyNode *node = fgGetNode("/gear/gear", i, true);
186 net->wow[i] = node->getDoubleValue("wow");
187 net->gear_pos[i] = node->getDoubleValue("position-norm");
188 net->gear_steer[i] = node->getDoubleValue("steering-norm");
189 net->gear_compression[i] = node->getDoubleValue("compression-norm");
192 // the following really aren't used in this context
193 net->cur_time = globals->get_time_params()->get_cur_time();
194 net->warp = globals->get_warp();
195 net->visibility = fgGetDouble("/environment/visibility-m");
197 // Control surface positions
198 SGPropertyNode *node = fgGetNode("/surface-positions", true);
199 net->elevator = node->getDoubleValue( "elevator-pos-norm" );
200 net->flaps = node->getDoubleValue( "flap-pos-norm" );
201 net->left_aileron = node->getDoubleValue( "left-aileron-pos-norm" );
202 net->right_aileron = node->getDoubleValue( "right-aileron-pos-norm" );
203 net->rudder = node->getDoubleValue( "rudder-pos-norm" );
204 net->speedbrake = node->getDoubleValue( "speedbrake-pos-norm" );
205 net->spoilers = node->getDoubleValue( "spoilers-pos-norm" );
207 if ( net_byte_order ) {
208 // Convert the net buffer to network format
209 net->version = htonl(net->version);
211 htond(net->longitude);
212 htond(net->latitude);
213 htond(net->altitude);
220 htonf(net->thetadot);
223 htonf(net->climb_rate);
227 htonf(net->v_wind_body_north);
228 htonf(net->v_wind_body_east);
229 htonf(net->v_wind_body_down);
230 htonf(net->stall_warning);
232 htonf(net->A_X_pilot);
233 htonf(net->A_Y_pilot);
234 htonf(net->A_Z_pilot);
236 for ( i = 0; i < net->num_engines; ++i ) {
237 net->eng_state[i] = htonl(net->eng_state[i]);
239 htonf(net->fuel_flow[i]);
241 htonf(net->oil_temp[i]);
242 htonf(net->oil_px[i]);
244 net->num_engines = htonl(net->num_engines);
246 for ( i = 0; i < net->num_tanks; ++i ) {
247 htonf(net->fuel_quantity[i]);
249 net->num_tanks = htonl(net->num_tanks);
251 for ( i = 0; i < net->num_wheels; ++i ) {
252 net->wow[i] = htonl(net->wow[i]);
253 htonf(net->gear_pos[i]);
254 htonf(net->gear_steer[i]);
255 htonf(net->gear_compression[i]);
257 net->num_wheels = htonl(net->num_wheels);
259 net->cur_time = htonl( net->cur_time );
260 net->warp = htonl( net->warp );
261 htonf(net->visibility);
263 htonf(net->elevator);
265 htonf(net->left_aileron);
266 htonf(net->right_aileron);
268 htonf(net->speedbrake);
269 htonf(net->spoilers);
274 void FGNetFDM2Props( FGNetFDM *net, bool net_byte_order ) {
277 if ( net_byte_order ) {
278 // Convert to the net buffer from network format
279 net->version = ntohl(net->version);
281 htond(net->longitude);
282 htond(net->latitude);
283 htond(net->altitude);
290 htonf(net->thetadot);
293 htonf(net->climb_rate);
297 htonf(net->v_wind_body_north);
298 htonf(net->v_wind_body_east);
299 htonf(net->v_wind_body_down);
300 htonf(net->stall_warning);
302 htonf(net->A_X_pilot);
303 htonf(net->A_Y_pilot);
304 htonf(net->A_Z_pilot);
306 net->num_engines = htonl(net->num_engines);
307 for ( i = 0; i < net->num_engines; ++i ) {
308 net->eng_state[i] = htonl(net->eng_state[i]);
310 htonf(net->fuel_flow[i]);
312 htonf(net->oil_temp[i]);
313 htonf(net->oil_px[i]);
316 net->num_tanks = htonl(net->num_tanks);
317 for ( i = 0; i < net->num_tanks; ++i ) {
318 htonf(net->fuel_quantity[i]);
321 net->num_wheels = htonl(net->num_wheels);
322 for ( i = 0; i < net->num_wheels; ++i ) {
323 net->wow[i] = htonl(net->wow[i]);
324 htonf(net->gear_pos[i]);
325 htonf(net->gear_steer[i]);
326 htonf(net->gear_compression[i]);
329 net->cur_time = ntohl(net->cur_time);
330 net->warp = ntohl(net->warp);
331 htonf(net->visibility);
333 htonf(net->elevator);
335 htonf(net->left_aileron);
336 htonf(net->right_aileron);
338 htonf(net->speedbrake);
339 htonf(net->spoilers);
342 if ( net->version == FG_NET_FDM_VERSION ) {
343 // cout << "pos = " << net->longitude << " " << net->latitude << endl;
344 // cout << "sea level rad = " << cur_fdm_state->get_Sea_level_radius()
346 cur_fdm_state->_updateGeodeticPosition( net->latitude,
349 * SG_METER_TO_FEET );
350 if ( net->agl > -9000 ) {
351 cur_fdm_state->_set_Altitude_AGL( net->agl * SG_METER_TO_FEET );
354 = net->altitude - globals->get_scenery()->get_cur_elev();
355 cur_fdm_state->_set_Altitude_AGL( agl_m * SG_METER_TO_FEET );
357 cur_fdm_state->_set_Euler_Angles( net->phi,
360 cur_fdm_state->_set_Euler_Rates( net->phidot,
363 cur_fdm_state->_set_V_calibrated_kts( net->vcas );
364 cur_fdm_state->_set_Climb_Rate( net->climb_rate );
365 cur_fdm_state->_set_Velocities_Local( net->v_north,
368 cur_fdm_state->_set_Velocities_Wind_Body( net->v_wind_body_north,
369 net->v_wind_body_east,
370 net->v_wind_body_down );
372 fgSetDouble( "/sim/alarms/stall-warning", net->stall_warning );
373 cur_fdm_state->_set_Accels_Pilot_Body( net->A_X_pilot,
377 for ( i = 0; i < net->num_engines; ++i ) {
378 SGPropertyNode *node = fgGetNode( "engines/engine", i, true );
380 // node->setBoolValue("running", t->isRunning());
381 // node->setBoolValue("cranking", t->isCranking());
383 // cout << net->eng_state[i] << endl;
384 if ( net->eng_state[i] == 0 ) {
385 node->setBoolValue( "cranking", false );
386 node->setBoolValue( "running", false );
387 } else if ( net->eng_state[i] == 1 ) {
388 node->setBoolValue( "cranking", true );
389 node->setBoolValue( "running", false );
390 } else if ( net->eng_state[i] == 2 ) {
391 node->setBoolValue( "cranking", false );
392 node->setBoolValue( "running", true );
395 node->setDoubleValue( "rpm", net->rpm[i] );
396 node->setDoubleValue( "fuel-flow-gph", net->fuel_flow[i] );
397 node->setDoubleValue( "egt-degf", net->EGT[i] );
398 node->setDoubleValue( "oil-temperature-degf", net->oil_temp[i] );
399 node->setDoubleValue( "oil-pressure-psi", net->oil_px[i] );
402 for (i = 0; i < net->num_tanks; ++i ) {
403 SGPropertyNode * node
404 = fgGetNode("/consumables/fuel/tank", i, true);
405 node->setDoubleValue("level-gal_us", net->fuel_quantity[i] );
408 for (i = 0; i < net->num_wheels; ++i ) {
409 SGPropertyNode * node = fgGetNode("/gear/gear", i, true);
410 node->setDoubleValue("wow", net->wow[i] );
411 node->setDoubleValue("position-norm", net->gear_pos[i] );
412 node->setDoubleValue("steering-norm", net->gear_steer[i] );
413 node->setDoubleValue("compression-norm", net->gear_compression[i] );
416 /* these are ignored for now ... */
418 if ( net->cur_time ) {
419 fgSetLong("/sim/time/cur-time-override", net->cur_time);
422 globals->set_warp( net->warp );
423 last_warp = net->warp;
426 SGPropertyNode *node = fgGetNode("/surface-positions", true);
427 node->setDoubleValue("elevator-pos-norm", net->elevator);
428 node->setDoubleValue("flap-pos-norm", net->flaps);
429 node->setDoubleValue("left-aileron-pos-norm", net->left_aileron);
430 node->setDoubleValue("right-aileron-pos-norm", net->right_aileron);
431 node->setDoubleValue("rudder-pos-norm", net->rudder);
432 node->setDoubleValue("speedbrake-pos-norm", net->speedbrake);
433 node->setDoubleValue("spoilers-pos-norm", net->spoilers);
435 SG_LOG( SG_IO, SG_ALERT,
436 "Error: version mismatch in FGNetFDM2Props()" );
437 SG_LOG( SG_IO, SG_ALERT,
438 "\tread " << net->version << " need " << FG_NET_FDM_VERSION );
439 SG_LOG( SG_IO, SG_ALERT,
440 "\tNeeds to upgrade net_fdm.hxx and recompile." );
445 // process work for this port
446 bool FGNativeFDM::process() {
447 SGIOChannel *io = get_io_channel();
448 int length = sizeof(buf);
450 if ( get_direction() == SG_IO_OUT ) {
451 // cout << "size of cur_fdm_state = " << length << endl;
452 FGProps2NetFDM( &buf );
453 if ( ! io->write( (char *)(& buf), length ) ) {
454 SG_LOG( SG_IO, SG_ALERT, "Error writing data." );
457 } else if ( get_direction() == SG_IO_IN ) {
458 if ( io->get_type() == sgFileType ) {
459 if ( io->read( (char *)(& buf), length ) == length ) {
460 SG_LOG( SG_IO, SG_DEBUG, "Success reading data." );
461 FGNetFDM2Props( &buf );
465 result = io->read( (char *)(& buf), length );
466 while ( result == length ) {
467 if ( result == length ) {
468 SG_LOG( SG_IO, SG_DEBUG, " Success reading data." );
469 FGNetFDM2Props( &buf );
471 result = io->read( (char *)(& buf), length );
481 bool FGNativeFDM::close() {
482 SGIOChannel *io = get_io_channel();
484 set_enabled( false );
486 if ( ! io->close() ) {