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 // these can probably get wiped as soon as David spots them. :-)
70 static const SGPropertyNode *aileron
71 = fgGetNode("/controls/aileron");
72 static const SGPropertyNode *elevator
73 = fgGetNode("/controls/elevator");
74 static const SGPropertyNode *elevator_trim
75 = fgGetNode("/controls/elevator-trim");
76 static const SGPropertyNode *rudder
77 = fgGetNode("/controls/rudder");
78 static const SGPropertyNode *flaps
79 = fgGetNode("/controls/flaps");
85 raw->version = FG_RAW_CTRLS_VERSION;
86 raw->aileron = fgGetDouble( "/controls/aileron" );
87 raw->elevator = fgGetDouble( "/controls/elevator" );
88 raw->elevator_trim = fgGetDouble( "/controls/elevator-trim" );
89 raw->rudder = fgGetDouble( "/controls/rudder" );
90 raw->flaps = fgGetDouble( "/controls/flaps" );
91 for ( i = 0; i < FG_MAX_ENGINES; ++i ) {
92 sprintf( buf, "/controls/throttle[%d]", i );
93 raw->throttle[i] = fgGetDouble( buf );
94 sprintf( buf, "/controls/mixture[%d]", i );
95 raw->mixture[i] = fgGetDouble( buf );
96 sprintf( buf, "/controls/propeller-pitch[%d]", i );
97 raw->prop_advance[i] = fgGetDouble( buf );
99 for ( i = 0; i < FG_MAX_WHEELS; ++i ) {
100 sprintf( buf, "/controls/brakes[%d]", i );
101 raw->brake[i] = fgGetDouble( buf );
103 raw->hground = fgGetDouble( "/environment/ground-elevation-m" );
104 raw->magvar = fgGetDouble("/environment/magnetic-variation-deg");
105 raw->speedup = fgGetInt("/sim/speed-up");
107 // convert to network byte order
108 raw->version = htonl(raw->version);
110 htond(raw->elevator);
111 htond(raw->elevator_trim);
114 for ( i = 0; i < FG_MAX_ENGINES; ++i ) {
115 htond(raw->throttle[i]);
116 htond(raw->mixture[i]);
117 htond(raw->prop_advance[i]);
119 for ( i = 0; i < FG_MAX_WHEELS; ++i ) {
120 htond(raw->brake[i]);
124 raw->speedup = htonl(raw->speedup);
128 static void net2global( FGNetFDM *net ) {
129 // Convert to the net buffer from network format
130 net->version = ntohl(net->version);
131 htond(net->longitude);
132 htond(net->latitude);
133 htond(net->altitude);
138 htond(net->thetadot);
141 htond(net->climb_rate);
142 htond(net->A_X_pilot);
143 htond(net->A_Y_pilot);
144 htond(net->A_Z_pilot);
145 net->cur_time = ntohl(net->cur_time);
146 net->warp = ntohl(net->warp);
147 htond(net->visibility);
149 if ( net->version == FG_NET_FDM_VERSION ) {
150 // cout << "pos = " << net->longitude << " " << net->latitude << endl;
151 // cout << "sea level rad = " << cur_fdm_state->get_Sea_level_radius() << endl;
152 cur_fdm_state->_updateGeodeticPosition( net->latitude,
155 * SG_METER_TO_FEET );
156 cur_fdm_state->_set_Euler_Angles( net->phi,
159 cur_fdm_state->_set_Euler_Rates( net->phidot,
162 cur_fdm_state->_set_V_calibrated_kts( net->vcas );
163 cur_fdm_state->_set_Climb_Rate( net->climb_rate );
164 cur_fdm_state->_set_Accels_Pilot_Body( net->A_X_pilot,
167 /* these are ignored for now ... */
169 if ( net->cur_time ) {
170 fgSetLong("/sim/time/cur-time-override", net->cur_time);
173 globals->set_warp( net->warp );
174 last_warp = net->warp;
177 SG_LOG( SG_IO, SG_ALERT, "Error: version mismatch in net2global()" );
178 SG_LOG( SG_IO, SG_ALERT,
179 "\tread " << net->version << " need " << FG_NET_FDM_VERSION );
180 SG_LOG( SG_IO, SG_ALERT,
181 "\tsomeone needs to upgrade net_fdm.hxx and recompile." );
186 FGExternalNet::FGExternalNet( double dt, int dop, int dip, int cp,
198 /////////////////////////////////////////////////////////
199 // Setup client udp connection (sends data to remote fdm)
201 if ( ! data_client.open( false ) ) {
202 SG_LOG( SG_FLIGHT, SG_ALERT, "Error opening client data channel" );
207 data_client.setBlocking( false );
209 if ( data_client.connect( fdm_host.c_str(), data_out_port ) == -1 ) {
210 printf("error connecting to %s:%d\n", fdm_host.c_str(), data_out_port);
214 /////////////////////////////////////////////////////////
215 // Setup server udp connection (for receiving data)
217 if ( ! data_server.open( false ) ) {
218 SG_LOG( SG_FLIGHT, SG_ALERT, "Error opening client server channel" );
222 // we want to block for incoming data in order to syncronize frame
224 data_server.setBlocking( false /* don't block while testing */ );
225 // data_server.setBlocking( true /* don't block while testing */ );
227 // if we bind to fdm_host = "" then we accept messages from
229 if ( data_server.bind( fdm_host.c_str(), data_in_port ) == -1 ) {
230 printf("error binding to port %d\n", data_in_port);
236 FGExternalNet::~FGExternalNet() {
242 // Initialize the ExternalNet flight model, dt is the time increment
243 // for each subsequent iteration through the EOM
244 void FGExternalNet::init() {
245 // cout << "FGExternalNet::init()" << endl;
247 // Explicitly call the superclass's
248 // init method first.
251 double lon = fgGetDouble( "/position/longitude-deg" );
252 double lat = fgGetDouble( "/position/latitude-deg" );
253 double ground = fgGetDouble( "/environment/ground-elevation-m" );
254 double heading = fgGetDouble("/orientation/heading-deg");
258 sprintf( cmd, "/longitude-deg?value=%.8f", lon );
259 new HTTPClient( fdm_host.c_str(), cmd_port, cmd );
260 // cout << "before loop()" << endl;
262 // cout << "here" << endl;
264 sprintf( cmd, "/latitude-deg?value=%.8f", lat );
265 new HTTPClient( fdm_host.c_str(), cmd_port, cmd );
268 sprintf( cmd, "/ground-m?value=%.8f", ground );
269 new HTTPClient( fdm_host.c_str(), cmd_port, cmd );
272 sprintf( cmd, "/heading-deg?value=%.8f", heading );
273 new HTTPClient( fdm_host.c_str(), cmd_port, cmd );
276 sprintf( cmd, "/reset?value=ground" );
277 new HTTPClient( fdm_host.c_str(), cmd_port, cmd );
282 // Run an iteration of the EOM. This is a NOP here because the flight
283 // model values are getting filled in elsewhere (most likely from some
285 void FGExternalNet::update( int multiloop ) {
289 // Send control positions to remote fdm
290 length = sizeof(ctrls);
291 global2raw( &ctrls );
292 if ( data_client.send( (char *)(& ctrls), length, 0 ) != length ) {
293 SG_LOG( SG_IO, SG_ALERT, "Error writing data." );
296 // Read next set of FDM data (blocking enabled to maintain 'sync')
297 length = sizeof(fdm);
298 if ( (result = data_server.recv( (char *)(& fdm), length, 0)) >= 0 ) {
299 SG_LOG( SG_IO, SG_DEBUG, "Success reading data." );