src/Network/native_fdm.cxx

   1 // native_fdm.cxx -- FGFS "Native" flight dynamics protocal class
   2 //
   3 // Written by Curtis Olson, started September 2001.
   4 //
   5 // Copyright (C) 2001  Curtis L. Olson - curt@flightgear.org
   6 //
   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.
  11 //
  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.
  16 //
  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.
  20 //
  21 // $Id$
  22
  23
  24 #ifdef HAVE_CONFIG_H
  25 #  include <config.h>
  26 #endif
  27
  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>
  32
  33 #include <FDM/flight.hxx>
  34 #include <Time/tmp.hxx>
  35 #include <Main/fg_props.hxx>
  36 #include <Main/globals.hxx>
  37
  38 #include "native_fdm.hxx"
  39
  40 // FreeBSD works better with this included last ... (?)
  41 #if defined(WIN32) && !defined(__CYGWIN__)
  42 #  include <windows.h>
  43 #else
  44 #  include <netinet/in.h>       // htonl() ntohl()
  45 #endif
  46
  47
  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
  56 // possible
  57 static void htond (double &x)
  58 {
  59     if ( sgIsLittleEndian() ) {
  60         int    *Double_Overlay;
  61         int     Holding_Buffer;
  62
  63         Double_Overlay = (int *) &x;
  64         Holding_Buffer = Double_Overlay [0];
  65
  66         Double_Overlay [0] = htonl (Double_Overlay [1]);
  67         Double_Overlay [1] = htonl (Holding_Buffer);
  68     } else {
  69         return;
  70     }
  71 }
  72
  73
  74 FGNativeFDM::FGNativeFDM() {
  75 }
  76
  77 FGNativeFDM::~FGNativeFDM() {
  78 }
  79
  80
  81 // open hailing frequencies
  82 bool FGNativeFDM::open() {
  83     if ( is_enabled() ) {
  84         SG_LOG( SG_IO, SG_ALERT, "This shouldn't happen, but the channel "
  85                 << "is already in use, ignoring" );
  86         return false;
  87     }
  88
  89     SGIOChannel *io = get_io_channel();
  90
  91     if ( ! io->open( get_direction() ) ) {
  92         SG_LOG( SG_IO, SG_ALERT, "Error opening channel communication layer." );
  93         return false;
  94     }
  95
  96     set_enabled( true );
  97
  98     cur_fdm_state->_set_Sea_level_radius( SG_EQUATORIAL_RADIUS_FT );
  99     return true;
 100 }
 101
 102
 103 void FGProps2NetFDM( FGNetFDM *net, bool net_byte_order ) {
 104     int i;
 105
 106     // Version sanity checking
 107     net->version = FG_NET_FDM_VERSION;
 108
 109     // Aero parameters
 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;
 120
 121     net->vcas = cur_fdm_state->get_V_calibrated_kts();
 122     net->climb_rate = cur_fdm_state->get_Climb_Rate();
 123
 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);
 131
 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();
 135
 136     // Engine parameters
 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;
 144         } else {
 145             net->eng_state[0] = 0;
 146         }
 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" );
 153     }
 154
 155     // Consumables
 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");
 160     }
 161
 162     // Gear and flaps
 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");
 167     }
 168
 169     // cout << "Flap deflection = " << aero->dflap << endl;
 170     net->flap_deflection = fgGetDouble("/surface-positions/flap-pos-norm" );
 171
 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");
 176
 177     if ( net_byte_order ) {
 178         // Convert the net buffer to network format
 179         net->version = htonl(net->version);
 180
 181         htond(net->longitude);
 182         htond(net->latitude);
 183         htond(net->altitude);
 184         htond(net->phi);
 185         htond(net->theta);
 186         htond(net->psi);
 187
 188         htond(net->phidot);
 189         htond(net->thetadot);
 190         htond(net->psidot);
 191         htond(net->vcas);
 192         htond(net->climb_rate);
 193         htond(net->v_north);
 194         htond(net->v_east);
 195         htond(net->v_down);
 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);
 200
 201         htond(net->A_X_pilot);
 202         htond(net->A_Y_pilot);
 203         htond(net->A_Z_pilot);
 204
 205         for ( i = 0; i < net->num_engines; ++i ) {
 206             htonl(net->eng_state[i]);
 207             htond(net->rpm[i]);
 208             htond(net->fuel_flow[i]);
 209             htond(net->EGT[i]);
 210             htond(net->oil_temp[i]);
 211             htond(net->oil_px[i]);
 212         }
 213         net->num_engines = htonl(net->num_engines);
 214
 215         for ( i = 0; i < net->num_tanks; ++i ) {
 216             htond(net->fuel_quantity[i]);
 217         }
 218         net->num_tanks = htonl(net->num_tanks);
 219
 220         for ( i = 0; i < net->num_wheels; ++i ) {
 221             net->wow[i] = htonl(net->wow[i]);
 222         }
 223         net->num_wheels = htonl(net->num_wheels);
 224         htond(net->flap_deflection);
 225
 226         net->cur_time = htonl( net->cur_time );
 227         net->warp = htonl( net->warp );
 228         htond(net->visibility);
 229     }
 230 }
 231
 232
 233 void FGNetFDM2Props( FGNetFDM *net, bool net_byte_order ) {
 234     int i;
 235
 236     if ( net_byte_order ) {
 237         // Convert to the net buffer from network format
 238         net->version = ntohl(net->version);
 239
 240         htond(net->longitude);
 241         htond(net->latitude);
 242         htond(net->altitude);
 243         htond(net->phi);
 244         htond(net->theta);
 245         htond(net->psi);
 246
 247         htond(net->phidot);
 248         htond(net->thetadot);
 249         htond(net->psidot);
 250         htond(net->vcas);
 251         htond(net->climb_rate);
 252         htond(net->v_north);
 253         htond(net->v_east);
 254         htond(net->v_down);
 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);
 259
 260         htond(net->A_X_pilot);
 261         htond(net->A_Y_pilot);
 262         htond(net->A_Z_pilot);
 263
 264         net->num_engines = htonl(net->num_engines);
 265         for ( i = 0; i < net->num_engines; ++i ) {
 266             htonl(net->eng_state[i]);
 267             htond(net->rpm[i]);
 268             htond(net->fuel_flow[i]);
 269             htond(net->EGT[i]);
 270             htond(net->oil_temp[i]);
 271             htond(net->oil_px[i]);
 272         }
 273
 274         net->num_tanks = htonl(net->num_tanks);
 275         for ( i = 0; i < net->num_tanks; ++i ) {
 276             htond(net->fuel_quantity[i]);
 277         }
 278
 279         net->num_wheels = htonl(net->num_wheels);
 280         // I don't need to convert the Wow flags, since they are one
 281         // byte in size
 282         htond(net->flap_deflection);
 283
 284         net->cur_time = ntohl(net->cur_time);
 285         net->warp = ntohl(net->warp);
 286         htond(net->visibility);
 287     }
 288
 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()
 292         //      << endl;
 293         cur_fdm_state->_updateGeodeticPosition( net->latitude,
 294                                                 net->longitude,
 295                                                 net->altitude
 296                                                   * SG_METER_TO_FEET );
 297         cur_fdm_state->_set_Euler_Angles( net->phi,
 298                                           net->theta,
 299                                           net->psi );
 300         cur_fdm_state->_set_Euler_Rates( net->phidot,
 301                                          net->thetadot,
 302                                          net->psidot );
 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,
 306                                               net->v_east,
 307                                               net->v_down );
 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 );
 311
 312         fgSetDouble( "/sim/alarms/stall-warning", net->stall_warning );
 313         cur_fdm_state->_set_Accels_Pilot_Body( net->A_X_pilot,
 314                                                net->A_Y_pilot,
 315                                                net->A_Z_pilot );
 316
 317         for ( i = 0; i < net->num_engines; ++i ) {
 318             SGPropertyNode *node = fgGetNode( "engines/engine", i, true );
 319
 320             // node->setBoolValue("running", t->isRunning());
 321             // node->setBoolValue("cranking", t->isCranking());
 322
 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 );
 333             }
 334
 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] );
 340         }
 341
 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] );
 346         }
 347
 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] );
 352         }
 353
 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" ));
 364
 365         /* these are ignored for now  ... */
 366         /*
 367         if ( net->cur_time ) {
 368             fgSetLong("/sim/time/cur-time-override", net->cur_time);
 369         }
 370
 371         globals->set_warp( net->warp );
 372         last_warp = net->warp;
 373         */
 374     } else {
 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." );
 381     }
 382 }
 383
 384
 385 // process work for this port
 386 bool FGNativeFDM::process() {
 387     SGIOChannel *io = get_io_channel();
 388     int length = sizeof(buf);
 389
 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." );
 395             return false;
 396         }
 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 );
 402             }
 403         } else {
 404             // double dt = 1000000.0 / 30.0;
 405             // SGTimeStamp current; current.stamp();
 406             int result;
 407             result = io->read( (char *)(& buf), length );
 408             if ( result == length ) {
 409                 SG_LOG( SG_IO, SG_DEBUG, "  Success reading data." );
 410                 FGNetFDM2Props( &buf );
 411             }
 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 );
 417                 }
 418                 // current.stamp();
 419             }
 420             // last_time = current;
 421         }
 422     }
 423
 424     return true;
 425 }
 426
 427
 428 // close the channel
 429 bool FGNativeFDM::close() {
 430     SGIOChannel *io = get_io_channel();
 431
 432     set_enabled( false );
 433
 434     if ( ! io->close() ) {
 435         return false;
 436     }
 437
 438     return true;
 439 }