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>
38 #include "native_fdm.hxx"
40 // FreeBSD works better with this included last ... (?)
41 #if defined(WIN32) && !defined(__CYGWIN__)
44 # include <netinet/in.h> // htonl() ntohl()
48 // The function htond is defined this way due to the way some
49 // processors and OSes treat floating point values. Some will raise
50 // an exception whenever a "bad" floating point value is loaded into a
51 // floating point register. Solaris is notorious for this, but then
52 // so is LynxOS on the PowerPC. By translating the data in place,
53 // there is no need to load a FP register with the "corruped" floating
54 // point value. By doing the BIG_ENDIAN test, I can optimize the
55 // routine for big-endian processors so it can be as efficient as
57 static void htond (double &x)
59 if ( sgIsLittleEndian() ) {
63 Double_Overlay = (int *) &x;
64 Holding_Buffer = Double_Overlay [0];
66 Double_Overlay [0] = htonl (Double_Overlay [1]);
67 Double_Overlay [1] = htonl (Holding_Buffer);
74 FGNativeFDM::FGNativeFDM() {
77 FGNativeFDM::~FGNativeFDM() {
81 // open hailing frequencies
82 bool FGNativeFDM::open() {
84 SG_LOG( SG_IO, SG_ALERT, "This shouldn't happen, but the channel "
85 << "is already in use, ignoring" );
89 SGIOChannel *io = get_io_channel();
91 if ( ! io->open( get_direction() ) ) {
92 SG_LOG( SG_IO, SG_ALERT, "Error opening channel communication layer." );
98 cur_fdm_state->_set_Sea_level_radius( SG_EQUATORIAL_RADIUS_FT );
103 void FGProps2NetFDM( FGNetFDM *net, bool net_byte_order ) {
106 // Version sanity checking
107 net->version = FG_NET_FDM_VERSION;
110 net->longitude = cur_fdm_state->get_Longitude();
111 net->latitude = cur_fdm_state->get_Latitude();
112 net->altitude = cur_fdm_state->get_Altitude() * SG_FEET_TO_METER;
113 net->phi = cur_fdm_state->get_Phi();
114 net->theta = cur_fdm_state->get_Theta();
115 net->psi = cur_fdm_state->get_Psi();
116 net->phidot = cur_fdm_state->get_Phi_dot_degps() * SG_DEGREES_TO_RADIANS;
117 net->thetadot = cur_fdm_state->get_Theta_dot_degps()
118 * SG_DEGREES_TO_RADIANS;
119 net->psidot = cur_fdm_state->get_Psi_dot_degps() * SG_DEGREES_TO_RADIANS;
121 net->vcas = cur_fdm_state->get_V_calibrated_kts();
122 net->climb_rate = cur_fdm_state->get_Climb_Rate();
124 net->v_north = cur_fdm_state->get_V_north();
125 net->v_east = cur_fdm_state->get_V_east();
126 net->v_down = cur_fdm_state->get_V_down();
127 net->v_wind_body_north = cur_fdm_state->get_uBody();
128 net->v_wind_body_east = cur_fdm_state->get_vBody();
129 net->v_wind_body_down = cur_fdm_state->get_wBody();
130 net->stall_warning = fgGetDouble("/sim/alarms/stall-warning", 0.0);
132 net->A_X_pilot = cur_fdm_state->get_A_X_pilot();
133 net->A_Y_pilot = cur_fdm_state->get_A_Y_pilot();
134 net->A_Z_pilot = cur_fdm_state->get_A_Z_pilot();
137 net->num_engines = FGNetFDM::FG_MAX_ENGINES;
138 for ( i = 0; i < net->num_engines; ++i ) {
139 SGPropertyNode *node = fgGetNode("engines/engine", i, true);
140 if ( node->getBoolValue( "running" ) ) {
141 net->eng_state[0] = 2;
142 } else if ( node->getBoolValue( "cranking" ) ) {
143 net->eng_state[0] = 1;
145 net->eng_state[0] = 0;
147 net->rpm[i] = node->getDoubleValue( "rpm" );
148 net->fuel_flow[i] = node->getDoubleValue( "fuel-flow-gph" );
149 net->EGT[i] = node->getDoubleValue( "egt-degf" );
150 // cout << "egt = " << aero->EGT << endl;
151 net->oil_temp[i] = node->getDoubleValue( "oil-temperature-degf" );
152 net->oil_px[i] = node->getDoubleValue( "oil-pressure-psi" );
156 net->num_tanks = FGNetFDM::FG_MAX_TANKS;
157 for ( i = 0; i < net->num_tanks; ++i ) {
158 SGPropertyNode *node = fgGetNode("/consumables/fuel/tank", i, true);
159 net->fuel_quantity[i] = node->getDoubleValue("level-gal_us");
163 net->num_wheels = FGNetFDM::FG_MAX_WHEELS;
164 for (i = 0; i < net->num_wheels; ++i ) {
165 SGPropertyNode *node = fgGetNode("/gear/gear", i, true);
166 net->wow[i] = node->getDoubleValue("wow");
169 // cout << "Flap deflection = " << aero->dflap << endl;
170 net->flap_deflection = fgGetDouble("/surface-positions/flap-pos-norm" );
172 // the following really aren't used in this context
173 net->cur_time = globals->get_time_params()->get_cur_time();
174 net->warp = globals->get_warp();
175 net->visibility = fgGetDouble("/environment/visibility-m");
177 if ( net_byte_order ) {
178 // Convert the net buffer to network format
179 net->version = htonl(net->version);
181 htond(net->longitude);
182 htond(net->latitude);
183 htond(net->altitude);
189 htond(net->thetadot);
192 htond(net->climb_rate);
196 htond(net->v_wind_body_north);
197 htond(net->v_wind_body_east);
198 htond(net->v_wind_body_down);
199 htond(net->stall_warning);
201 htond(net->A_X_pilot);
202 htond(net->A_Y_pilot);
203 htond(net->A_Z_pilot);
205 for ( i = 0; i < net->num_engines; ++i ) {
206 htonl(net->eng_state[i]);
208 htond(net->fuel_flow[i]);
210 htond(net->oil_temp[i]);
211 htond(net->oil_px[i]);
213 net->num_engines = htonl(net->num_engines);
215 for ( i = 0; i < net->num_tanks; ++i ) {
216 htond(net->fuel_quantity[i]);
218 net->num_tanks = htonl(net->num_tanks);
220 for ( i = 0; i < net->num_wheels; ++i ) {
221 net->wow[i] = htonl(net->wow[i]);
223 net->num_wheels = htonl(net->num_wheels);
224 htond(net->flap_deflection);
226 net->cur_time = htonl( net->cur_time );
227 net->warp = htonl( net->warp );
228 htond(net->visibility);
233 void FGNetFDM2Props( FGNetFDM *net, bool net_byte_order ) {
236 if ( net_byte_order ) {
237 // Convert to the net buffer from network format
238 net->version = ntohl(net->version);
240 htond(net->longitude);
241 htond(net->latitude);
242 htond(net->altitude);
248 htond(net->thetadot);
251 htond(net->climb_rate);
255 htond(net->v_wind_body_north);
256 htond(net->v_wind_body_east);
257 htond(net->v_wind_body_down);
258 htond(net->stall_warning);
260 htond(net->A_X_pilot);
261 htond(net->A_Y_pilot);
262 htond(net->A_Z_pilot);
264 net->num_engines = htonl(net->num_engines);
265 for ( i = 0; i < net->num_engines; ++i ) {
266 htonl(net->eng_state[i]);
268 htond(net->fuel_flow[i]);
270 htond(net->oil_temp[i]);
271 htond(net->oil_px[i]);
274 net->num_tanks = htonl(net->num_tanks);
275 for ( i = 0; i < net->num_tanks; ++i ) {
276 htond(net->fuel_quantity[i]);
279 net->num_wheels = htonl(net->num_wheels);
280 // I don't need to convert the Wow flags, since they are one
282 htond(net->flap_deflection);
284 net->cur_time = ntohl(net->cur_time);
285 net->warp = ntohl(net->warp);
286 htond(net->visibility);
289 if ( net->version == FG_NET_FDM_VERSION ) {
290 // cout << "pos = " << net->longitude << " " << net->latitude << endl;
291 // cout << "sea level rad = " << cur_fdm_state->get_Sea_level_radius()
293 cur_fdm_state->_updateGeodeticPosition( net->latitude,
296 * SG_METER_TO_FEET );
297 cur_fdm_state->_set_Euler_Angles( net->phi,
300 cur_fdm_state->_set_Euler_Rates( net->phidot,
303 cur_fdm_state->_set_V_calibrated_kts( net->vcas );
304 cur_fdm_state->_set_Climb_Rate( net->climb_rate );
305 cur_fdm_state->_set_Velocities_Local( net->v_north,
308 cur_fdm_state->_set_Velocities_Wind_Body( net->v_wind_body_north,
309 net->v_wind_body_east,
310 net->v_wind_body_down );
312 fgSetDouble( "/sim/alarms/stall-warning", net->stall_warning );
313 cur_fdm_state->_set_Accels_Pilot_Body( net->A_X_pilot,
317 for ( i = 0; i < net->num_engines; ++i ) {
318 SGPropertyNode *node = fgGetNode( "engines/engine", i, true );
320 // node->setBoolValue("running", t->isRunning());
321 // node->setBoolValue("cranking", t->isCranking());
323 // cout << net->eng_state[i] << endl;
324 if ( net->eng_state[i] == 0 ) {
325 node->setBoolValue( "cranking", false );
326 node->setBoolValue( "running", false );
327 } else if ( net->eng_state[i] == 1 ) {
328 node->setBoolValue( "cranking", true );
329 node->setBoolValue( "running", false );
330 } else if ( net->eng_state[i] == 2 ) {
331 node->setBoolValue( "cranking", false );
332 node->setBoolValue( "running", true );
335 node->setDoubleValue( "rpm", net->rpm[i] );
336 node->setDoubleValue( "fuel-flow-gph", net->fuel_flow[i] );
337 node->setDoubleValue( "egt-degf", net->EGT[i] );
338 node->setDoubleValue( "oil-temperature-degf", net->oil_temp[i] );
339 node->setDoubleValue( "oil-pressure-psi", net->oil_px[i] );
342 for (i = 0; i < net->num_tanks; ++i ) {
343 SGPropertyNode * node
344 = fgGetNode("/consumables/fuel/tank", i, true);
345 node->setDoubleValue("level-gal_us", net->fuel_quantity[i] );
348 for (i = 0; i < net->num_wheels; ++i ) {
349 SGPropertyNode * node
350 = fgGetNode("/gear/gear", i, true);
351 node->setDoubleValue("wow", net->wow[i] );
354 fgSetDouble("/surface-positions/flap-pos-norm", net->flap_deflection);
355 SGPropertyNode * node = fgGetNode("/controls", true);
356 fgSetDouble("/surface-positions/elevator-pos-norm",
357 node->getDoubleValue( "elevator" ));
358 fgSetDouble("/surface-positions/rudder-pos-norm",
359 node->getDoubleValue( "rudder" ));
360 fgSetDouble("/surface-positions/left-aileron-pos-norm",
361 node->getDoubleValue( "aileron" ));
362 fgSetDouble("/surface-positions/right-aileron-pos-norm",
363 -node->getDoubleValue( "aileron" ));
365 /* these are ignored for now ... */
367 if ( net->cur_time ) {
368 fgSetLong("/sim/time/cur-time-override", net->cur_time);
371 globals->set_warp( net->warp );
372 last_warp = net->warp;
375 SG_LOG( SG_IO, SG_ALERT,
376 "Error: version mismatch in FGNetFDM2Props()" );
377 SG_LOG( SG_IO, SG_ALERT,
378 "\tread " << net->version << " need " << FG_NET_FDM_VERSION );
379 SG_LOG( SG_IO, SG_ALERT,
380 "\tNeeds to upgrade net_fdm.hxx and recompile." );
385 // process work for this port
386 bool FGNativeFDM::process() {
387 SGIOChannel *io = get_io_channel();
388 int length = sizeof(buf);
390 if ( get_direction() == SG_IO_OUT ) {
391 // cout << "size of cur_fdm_state = " << length << endl;
392 FGProps2NetFDM( &buf );
393 if ( ! io->write( (char *)(& buf), length ) ) {
394 SG_LOG( SG_IO, SG_ALERT, "Error writing data." );
397 } else if ( get_direction() == SG_IO_IN ) {
398 if ( io->get_type() == sgFileType ) {
399 if ( io->read( (char *)(& buf), length ) == length ) {
400 SG_LOG( SG_IO, SG_DEBUG, "Success reading data." );
401 FGNetFDM2Props( &buf );
404 // double dt = 1000000.0 / 30.0;
405 // SGTimeStamp current; current.stamp();
407 result = io->read( (char *)(& buf), length );
408 if ( result == length ) {
409 SG_LOG( SG_IO, SG_DEBUG, " Success reading data." );
410 FGNetFDM2Props( &buf );
412 while ( result == length /* || current - last_time < dt */ ) {
413 result = io->read( (char *)(& buf), length );
414 if ( result == length ) {
415 SG_LOG( SG_IO, SG_DEBUG, " Success reading data." );
416 FGNetFDM2Props( &buf );
420 // last_time = current;
429 bool FGNativeFDM::close() {
430 SGIOChannel *io = get_io_channel();
432 set_enabled( false );
434 if ( ! io->close() ) {