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 #include <Scenery/scenery.hxx>
  38
  39 #include "native_fdm.hxx"
  40
  41 // FreeBSD works better with this included last ... (?)
  42 #if defined(WIN32) && !defined(__CYGWIN__)
  43 #  include <windows.h>
  44 #else
  45 #  include <netinet/in.h>       // htonl() ntohl()
  46 #endif
  47
  48
  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
  57 // possible
  58 static void htond (double &x)
  59 {
  60     if ( sgIsLittleEndian() ) {
  61         int    *Double_Overlay;
  62         int     Holding_Buffer;
  63
  64         Double_Overlay = (int *) &x;
  65         Holding_Buffer = Double_Overlay [0];
  66
  67         Double_Overlay [0] = htonl (Double_Overlay [1]);
  68         Double_Overlay [1] = htonl (Holding_Buffer);
  69     } else {
  70         return;
  71     }
  72 }
  73
  74 // Float version
  75 static void htonf (float &x)
  76 {
  77     if ( sgIsLittleEndian() ) {
  78         int    *Float_Overlay;
  79         int     Holding_Buffer;
  80
  81         Float_Overlay = (int *) &x;
  82         Holding_Buffer = Float_Overlay [0];
  83
  84         Float_Overlay [0] = htonl (Holding_Buffer);
  85     } else {
  86         return;
  87     }
  88 }
  89
  90
  91 FGNativeFDM::FGNativeFDM() {
  92 }
  93
  94 FGNativeFDM::~FGNativeFDM() {
  95 }
  96
  97
  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" );
 103         return false;
 104     }
 105
 106     SGIOChannel *io = get_io_channel();
 107
 108     if ( ! io->open( get_direction() ) ) {
 109         SG_LOG( SG_IO, SG_ALERT, "Error opening channel communication layer." );
 110         return false;
 111     }
 112
 113     set_enabled( true );
 114
 115     // Is this really needed here ????
 116     cur_fdm_state->_set_Sea_level_radius( SG_EQUATORIAL_RADIUS_FT );
 117
 118     return true;
 119 }
 120
 121
 122 void FGProps2NetFDM( FGNetFDM *net, bool net_byte_order ) {
 123     int i;
 124
 125     // Version sanity checking
 126     net->version = FG_NET_FDM_VERSION;
 127
 128     // Aero parameters
 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;
 140
 141     net->vcas = cur_fdm_state->get_V_calibrated_kts();
 142     net->climb_rate = cur_fdm_state->get_Climb_Rate();
 143
 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);
 151
 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();
 155
 156     // Engine parameters
 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;
 164         } else {
 165             net->eng_state[0] = 0;
 166         }
 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" );
 173     }
 174
 175     // Consumables
 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");
 180     }
 181
 182     // Gear and flaps
 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");
 190     }
 191
 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");
 196
 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" );
 206
 207     if ( net_byte_order ) {
 208         // Convert the net buffer to network format
 209         net->version = htonl(net->version);
 210
 211         htond(net->longitude);
 212         htond(net->latitude);
 213         htond(net->altitude);
 214         htonf(net->agl);
 215         htonf(net->phi);
 216         htonf(net->theta);
 217         htonf(net->psi);
 218
 219         htonf(net->phidot);
 220         htonf(net->thetadot);
 221         htonf(net->psidot);
 222         htonf(net->vcas);
 223         htonf(net->climb_rate);
 224         htonf(net->v_north);
 225         htonf(net->v_east);
 226         htonf(net->v_down);
 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);
 231
 232         htonf(net->A_X_pilot);
 233         htonf(net->A_Y_pilot);
 234         htonf(net->A_Z_pilot);
 235
 236         for ( i = 0; i < net->num_engines; ++i ) {
 237             net->eng_state[i] = htonl(net->eng_state[i]);
 238             htonf(net->rpm[i]);
 239             htonf(net->fuel_flow[i]);
 240             htonf(net->EGT[i]);
 241             htonf(net->oil_temp[i]);
 242             htonf(net->oil_px[i]);
 243         }
 244         net->num_engines = htonl(net->num_engines);
 245
 246         for ( i = 0; i < net->num_tanks; ++i ) {
 247             htonf(net->fuel_quantity[i]);
 248         }
 249         net->num_tanks = htonl(net->num_tanks);
 250
 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]);
 256         }
 257         net->num_wheels = htonl(net->num_wheels);
 258
 259         net->cur_time = htonl( net->cur_time );
 260         net->warp = htonl( net->warp );
 261         htonf(net->visibility);
 262
 263         htonf(net->elevator);
 264         htonf(net->flaps);
 265         htonf(net->left_aileron);
 266         htonf(net->right_aileron);
 267         htonf(net->rudder);
 268         htonf(net->speedbrake);
 269         htonf(net->spoilers);
 270     }
 271 }
 272
 273
 274 void FGNetFDM2Props( FGNetFDM *net, bool net_byte_order ) {
 275     int i;
 276
 277     if ( net_byte_order ) {
 278         // Convert to the net buffer from network format
 279         net->version = ntohl(net->version);
 280
 281         htond(net->longitude);
 282         htond(net->latitude);
 283         htond(net->altitude);
 284         htonf(net->agl);
 285         htonf(net->phi);
 286         htonf(net->theta);
 287         htonf(net->psi);
 288
 289         htonf(net->phidot);
 290         htonf(net->thetadot);
 291         htonf(net->psidot);
 292         htonf(net->vcas);
 293         htonf(net->climb_rate);
 294         htonf(net->v_north);
 295         htonf(net->v_east);
 296         htonf(net->v_down);
 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);
 301
 302         htonf(net->A_X_pilot);
 303         htonf(net->A_Y_pilot);
 304         htonf(net->A_Z_pilot);
 305
 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]);
 309             htonf(net->rpm[i]);
 310             htonf(net->fuel_flow[i]);
 311             htonf(net->EGT[i]);
 312             htonf(net->oil_temp[i]);
 313             htonf(net->oil_px[i]);
 314         }
 315
 316         net->num_tanks = htonl(net->num_tanks);
 317         for ( i = 0; i < net->num_tanks; ++i ) {
 318             htonf(net->fuel_quantity[i]);
 319         }
 320
 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]);
 327         }
 328
 329         net->cur_time = ntohl(net->cur_time);
 330         net->warp = ntohl(net->warp);
 331         htonf(net->visibility);
 332
 333         htonf(net->elevator);
 334         htonf(net->flaps);
 335         htonf(net->left_aileron);
 336         htonf(net->right_aileron);
 337         htonf(net->rudder);
 338         htonf(net->speedbrake);
 339         htonf(net->spoilers);
 340     }
 341
 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()
 345         //      << endl;
 346         cur_fdm_state->_updateGeodeticPosition( net->latitude,
 347                                                 net->longitude,
 348                                                 net->altitude
 349                                                   * SG_METER_TO_FEET );
 350         if ( net->agl > -9000 ) {
 351             cur_fdm_state->_set_Altitude_AGL( net->agl * SG_METER_TO_FEET );
 352         } else {
 353             double agl_m
 354               = net->altitude - globals->get_scenery()->get_cur_elev();
 355             cur_fdm_state->_set_Altitude_AGL( agl_m * SG_METER_TO_FEET );
 356         }
 357         cur_fdm_state->_set_Euler_Angles( net->phi,
 358                                           net->theta,
 359                                           net->psi );
 360         cur_fdm_state->_set_Euler_Rates( net->phidot,
 361                                          net->thetadot,
 362                                          net->psidot );
 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,
 366                                               net->v_east,
 367                                               net->v_down );
 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 );
 371
 372         fgSetDouble( "/sim/alarms/stall-warning", net->stall_warning );
 373         cur_fdm_state->_set_Accels_Pilot_Body( net->A_X_pilot,
 374                                                net->A_Y_pilot,
 375                                                net->A_Z_pilot );
 376
 377         for ( i = 0; i < net->num_engines; ++i ) {
 378             SGPropertyNode *node = fgGetNode( "engines/engine", i, true );
 379
 380             // node->setBoolValue("running", t->isRunning());
 381             // node->setBoolValue("cranking", t->isCranking());
 382
 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 );
 393             }
 394
 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] );
 400         }
 401
 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] );
 406         }
 407
 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] );
 414         }
 415
 416         /* these are ignored for now  ... */
 417         /*
 418         if ( net->cur_time ) {
 419             fgSetLong("/sim/time/cur-time-override", net->cur_time);
 420         }
 421
 422         globals->set_warp( net->warp );
 423         last_warp = net->warp;
 424         */
 425
 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);
 434     } else {
 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." );
 441     }
 442 }
 443
 444
 445 // process work for this port
 446 bool FGNativeFDM::process() {
 447     SGIOChannel *io = get_io_channel();
 448     int length = sizeof(buf);
 449
 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." );
 455             return false;
 456         }
 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 );
 462             }
 463         } else {
 464             int result;
 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 );
 470                 }
 471                 result = io->read( (char *)(& buf), length );
 472             }
 473         }
 474     }
 475
 476     return true;
 477 }
 478
 479
 480 // close the channel
 481 bool FGNativeFDM::close() {
 482     SGIOChannel *io = get_io_channel();
 483
 484     set_enabled( false );
 485
 486     if ( ! io->close() ) {
 487         return false;
 488     }
 489
 490     return true;
 491 }