1 // ExternalNet.hxx -- an net interface to an external flight dynamics model
3 // Written by Curtis Olson, started November 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.
23 #include <simgear/debug/logstream.hxx>
24 #include <simgear/io/lowlevel.hxx> // endian tests
26 #include <Main/fg_props.hxx>
28 #include "ExternalNet.hxx"
31 // FreeBSD works better with this included last ... (?)
32 #if defined(WIN32) && !defined(__CYGWIN__)
35 # include <netinet/in.h> // htonl() ntohl()
39 // The function htond is defined this way due to the way some
40 // processors and OSes treat floating point values. Some will raise
41 // an exception whenever a "bad" floating point value is loaded into a
42 // floating point register. Solaris is notorious for this, but then
43 // so is LynxOS on the PowerPC. By translating the data in place,
44 // there is no need to load a FP register with the "corruped" floating
45 // point value. By doing the BIG_ENDIAN test, I can optimize the
46 // routine for big-endian processors so it can be as efficient as
48 static void htond (double &x)
50 if ( sgIsLittleEndian() ) {
54 Double_Overlay = (int *) &x;
55 Holding_Buffer = Double_Overlay [0];
57 Double_Overlay [0] = htonl (Double_Overlay [1]);
58 Double_Overlay [1] = htonl (Holding_Buffer);
65 static void global2raw( FGRawCtrls *raw ) {
69 SGPropertyNode * node = fgGetNode("/controls", true);
70 raw->version = FG_RAW_CTRLS_VERSION;
71 raw->aileron = node->getDoubleValue( "aileron" );
72 raw->elevator = node->getDoubleValue( "elevator" );
73 raw->elevator_trim = node->getDoubleValue( "elevator-trim" );
74 raw->rudder = node->getDoubleValue( "rudder" );
75 raw->flaps = node->getDoubleValue( "flaps" );
76 for ( i = 0; i < FGRawCtrls::FG_MAX_ENGINES; ++i ) {
77 raw->throttle[i] = node->getDoubleValue( "throttle", i );
78 raw->mixture[i] = node->getDoubleValue( "mixture", i );
79 raw->prop_advance[i] = node->getDoubleValue( "propeller-pitch", i );
80 raw->magnetos[i] = node->getIntValue( "magnetos", i );
81 raw->starter[i] = node->getBoolValue( "starter", i );
83 for ( i = 0; i < FGRawCtrls::FG_MAX_WHEELS; ++i ) {
84 raw->brake[i] = node->getDoubleValue( "brakes", i );
86 raw->hground = fgGetDouble( "/environment/ground-elevation-m" );
87 raw->magvar = fgGetDouble("/environment/magnetic-variation-deg");
88 raw->speedup = fgGetInt("/sim/speed-up");
90 // convert to network byte order
91 raw->version = htonl(raw->version);
94 htond(raw->elevator_trim);
97 for ( i = 0; i < FGRawCtrls::FG_MAX_ENGINES; ++i ) {
98 htond(raw->throttle[i]);
99 htond(raw->mixture[i]);
100 htond(raw->prop_advance[i]);
101 htonl(raw->magnetos[i]);
102 htonl(raw->starter[i]);
104 for ( i = 0; i < FGRawCtrls::FG_MAX_WHEELS; ++i ) {
105 htond(raw->brake[i]);
109 raw->speedup = htonl(raw->speedup);
113 static void net2global( FGNetFDM *net ) {
116 // Convert to the net buffer from network format
117 net->version = ntohl(net->version);
119 htond(net->longitude);
120 htond(net->latitude);
121 htond(net->altitude);
127 htond(net->thetadot);
130 htond(net->climb_rate);
132 htond(net->A_X_pilot);
133 htond(net->A_Y_pilot);
134 htond(net->A_Z_pilot);
136 net->num_engines = htonl(net->num_engines);
137 for ( i = 0; i < net->num_engines; ++i ) {
138 htonl(net->eng_state[i]);
140 htond(net->fuel_flow[i]);
142 htond(net->oil_temp[i]);
143 htond(net->oil_px[i]);
146 net->num_tanks = htonl(net->num_tanks);
147 for ( i = 0; i < net->num_tanks; ++i ) {
148 htond(net->fuel_quantity[i]);
151 net->num_wheels = htonl(net->num_wheels);
152 for ( i = 0; i < net->num_wheels; ++i ) {
153 net->wow[i] = htonl(net->wow[i]);
156 net->cur_time = ntohl(net->cur_time);
157 net->warp = ntohl(net->warp);
158 htond(net->visibility);
160 if ( net->version == FG_NET_FDM_VERSION ) {
161 // cout << "pos = " << net->longitude << " " << net->latitude << endl;
162 // cout << "sea level rad = " << cur_fdm_state->get_Sea_level_radius()
164 cur_fdm_state->_updateGeodeticPosition( net->latitude,
167 * SG_METER_TO_FEET );
168 cur_fdm_state->_set_Euler_Angles( net->phi,
171 cur_fdm_state->_set_Euler_Rates( net->phidot,
174 cur_fdm_state->_set_V_calibrated_kts( net->vcas );
175 cur_fdm_state->_set_Climb_Rate( net->climb_rate );
176 cur_fdm_state->_set_Accels_Pilot_Body( net->A_X_pilot,
180 for ( i = 0; i < net->num_engines; ++i ) {
181 SGPropertyNode *node = fgGetNode( "engines/engine", i, true );
183 // node->setBoolValue("running", t->isRunning());
184 // node->setBoolValue("cranking", t->isCranking());
186 // cout << net->eng_state[i] << endl;
187 if ( net->eng_state[i] == 0 ) {
188 node->setBoolValue( "cranking", false );
189 node->setBoolValue( "running", false );
190 } else if ( net->eng_state[i] == 1 ) {
191 node->setBoolValue( "cranking", true );
192 node->setBoolValue( "running", false );
193 } else if ( net->eng_state[i] == 2 ) {
194 node->setBoolValue( "cranking", false );
195 node->setBoolValue( "running", true );
198 node->setDoubleValue( "rpm", net->rpm[i] );
199 node->setDoubleValue( "fuel-flow-gph", net->fuel_flow[i] );
200 node->setDoubleValue( "egt-degf", net->EGT[i] );
201 node->setDoubleValue( "oil-temperature-degf", net->oil_temp[i] );
202 node->setDoubleValue( "oil-pressure-psi", net->oil_px[i] );
205 for (i = 0; i < net->num_tanks; ++i ) {
206 SGPropertyNode * node
207 = fgGetNode("/consumables/fuel/tank", i, true);
208 node->setDoubleValue("level-gal_us", net->fuel_quantity[i] );
211 for (i = 0; i < net->num_wheels; ++i ) {
212 SGPropertyNode * node
213 = fgGetNode("/gear/gear", i, true);
214 node->setDoubleValue("wow", net->wow[i] );
217 /* these are ignored for now ... */
219 if ( net->cur_time ) {
220 fgSetLong("/sim/time/cur-time-override", net->cur_time);
223 globals->set_warp( net->warp );
224 last_warp = net->warp;
227 SG_LOG( SG_IO, SG_ALERT, "Error: version mismatch in net2global()" );
228 SG_LOG( SG_IO, SG_ALERT,
229 "\tread " << net->version << " need " << FG_NET_FDM_VERSION );
230 SG_LOG( SG_IO, SG_ALERT,
231 "\tsomeone needs to upgrade net_fdm.hxx and recompile." );
236 FGExternalNet::FGExternalNet( double dt, string host, int dop, int dip, int cp )
247 /////////////////////////////////////////////////////////
248 // Setup client udp connection (sends data to remote fdm)
250 if ( ! data_client.open( false ) ) {
251 SG_LOG( SG_FLIGHT, SG_ALERT, "Error opening client data channel" );
256 data_client.setBlocking( false );
258 if ( data_client.connect( fdm_host.c_str(), data_out_port ) == -1 ) {
259 printf("error connecting to %s:%d\n", fdm_host.c_str(), data_out_port);
263 /////////////////////////////////////////////////////////
264 // Setup server udp connection (for receiving data)
266 if ( ! data_server.open( false ) ) {
267 SG_LOG( SG_FLIGHT, SG_ALERT, "Error opening client server channel" );
271 // we want to block for incoming data in order to syncronize frame
273 data_server.setBlocking( false /* don't block while testing */ );
274 // data_server.setBlocking( true /* don't block while testing */ );
276 // if we bind to fdm_host = "" then we accept messages from
278 if ( data_server.bind( fdm_host.c_str(), data_in_port ) == -1 ) {
279 printf("error binding to port %d\n", data_in_port);
285 FGExternalNet::~FGExternalNet() {
291 // Initialize the ExternalNet flight model, dt is the time increment
292 // for each subsequent iteration through the EOM
293 void FGExternalNet::init() {
294 // cout << "FGExternalNet::init()" << endl;
296 // Explicitly call the superclass's
297 // init method first.
300 double lon = fgGetDouble( "/position/longitude-deg" );
301 double lat = fgGetDouble( "/position/latitude-deg" );
302 double ground = fgGetDouble( "/environment/ground-elevation-m" );
303 double heading = fgGetDouble("/orientation/heading-deg");
307 sprintf( cmd, "/longitude-deg?value=%.8f", lon );
308 new HTTPClient( fdm_host.c_str(), cmd_port, cmd );
309 // cout << "before loop()" << endl;
311 // cout << "here" << endl;
313 sprintf( cmd, "/latitude-deg?value=%.8f", lat );
314 new HTTPClient( fdm_host.c_str(), cmd_port, cmd );
317 sprintf( cmd, "/ground-m?value=%.8f", ground );
318 new HTTPClient( fdm_host.c_str(), cmd_port, cmd );
321 sprintf( cmd, "/heading-deg?value=%.8f", heading );
322 new HTTPClient( fdm_host.c_str(), cmd_port, cmd );
325 sprintf( cmd, "/reset?value=ground" );
326 new HTTPClient( fdm_host.c_str(), cmd_port, cmd );
331 // Run an iteration of the EOM. This is a NOP here because the flight
332 // model values are getting filled in elsewhere (most likely from some
334 void FGExternalNet::update( int multiloop ) {
338 // Send control positions to remote fdm
339 length = sizeof(ctrls);
340 global2raw( &ctrls );
341 if ( data_client.send( (char *)(& ctrls), length, 0 ) != length ) {
342 SG_LOG( SG_IO, SG_ALERT, "Error writing data." );
345 // Read next set of FDM data (blocking enabled to maintain 'sync')
346 length = sizeof(fdm);
347 if ( (result = data_server.recv( (char *)(& fdm), length, 0)) >= 0 ) {
348 SG_LOG( SG_IO, SG_DEBUG, "Success reading data." );