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 - http://www.flightgear.org/~curt
   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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 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/flightProperties.hxx>
  34 #include <Main/fg_props.hxx>
  35 #include <Main/globals.hxx>
  36 #include <Scenery/scenery.hxx>
  37
  38 #include "native_fdm.hxx"
  39
  40 // FreeBSD works better with this included last ... (?)
  41 #if defined( _MSC_VER )
  42 #  include <windows.h>
  43 #elif defined( __MINGW32__ )
  44 #  include <winsock2.h>
  45 #else
  46 #  include <netinet/in.h>       // htonl() ntohl()
  47 #endif
  48
  49
  50 // The function htond is defined this way due to the way some
  51 // processors and OSes treat floating point values.  Some will raise
  52 // an exception whenever a "bad" floating point value is loaded into a
  53 // floating point register.  Solaris is notorious for this, but then
  54 // so is LynxOS on the PowerPC.  By translating the data in place,
  55 // there is no need to load a FP register with the "corruped" floating
  56 // point value.  By doing the BIG_ENDIAN test, I can optimize the
  57 // routine for big-endian processors so it can be as efficient as
  58 // possible
  59 static void htond (double &x)
  60 {
  61     if ( sgIsLittleEndian() ) {
  62         int    *Double_Overlay;
  63         int     Holding_Buffer;
  64
  65         Double_Overlay = (int *) &x;
  66         Holding_Buffer = Double_Overlay [0];
  67
  68         Double_Overlay [0] = htonl (Double_Overlay [1]);
  69         Double_Overlay [1] = htonl (Holding_Buffer);
  70     } else {
  71         return;
  72     }
  73 }
  74
  75 // Float version
  76 static void htonf (float &x)
  77 {
  78     if ( sgIsLittleEndian() ) {
  79         int    *Float_Overlay;
  80         int     Holding_Buffer;
  81
  82         Float_Overlay = (int *) &x;
  83         Holding_Buffer = Float_Overlay [0];
  84
  85         Float_Overlay [0] = htonl (Holding_Buffer);
  86     } else {
  87         return;
  88     }
  89 }
  90
  91
  92 FGNativeFDM::FGNativeFDM() {
  93 }
  94
  95 FGNativeFDM::~FGNativeFDM() {
  96 }
  97
  98
  99 // open hailing frequencies
 100 bool FGNativeFDM::open() {
 101     if ( is_enabled() ) {
 102         SG_LOG( SG_IO, SG_ALERT, "This shouldn't happen, but the channel "
 103                 << "is already in use, ignoring" );
 104         return false;
 105     }
 106
 107     SGIOChannel *io = get_io_channel();
 108
 109     if ( ! io->open( get_direction() ) ) {
 110         SG_LOG( SG_IO, SG_ALERT, "Error opening channel communication layer." );
 111         return false;
 112     }
 113
 114     set_enabled( true );
 115
 116     // Is this really needed here ????
 117     fgSetDouble("/position/sea-level-radius-ft", SG_EQUATORIAL_RADIUS_FT);
 118
 119
 120
 121     return true;
 122 }
 123
 124
 125 void FGProps2NetFDM( FGNetFDM *net, bool net_byte_order ) {
 126     unsigned int i;
 127
 128     FlightProperties fdm_state;
 129
 130     // Version sanity checking
 131     net->version = FG_NET_FDM_VERSION;
 132
 133     // Aero parameters
 134     net->longitude = fdm_state.get_Longitude();
 135     net->latitude = fdm_state.get_Latitude();
 136     net->altitude = fdm_state.get_Altitude() * SG_FEET_TO_METER;
 137     net->agl = fdm_state.get_Altitude_AGL() * SG_FEET_TO_METER;
 138     net->phi = fdm_state.get_Phi();
 139     net->theta = fdm_state.get_Theta();
 140     net->psi = fdm_state.get_Psi();
 141     net->alpha = fdm_state.get_Alpha();
 142     net->beta = fdm_state.get_Beta();
 143     net->phidot = fdm_state.get_Phi_dot_degps() * SG_DEGREES_TO_RADIANS;
 144     net->thetadot = fdm_state.get_Theta_dot_degps()
 145         * SG_DEGREES_TO_RADIANS;
 146     net->psidot = fdm_state.get_Psi_dot_degps() * SG_DEGREES_TO_RADIANS;
 147
 148     net->vcas = fdm_state.get_V_calibrated_kts();
 149     net->climb_rate = fdm_state.get_Climb_Rate();
 150
 151     net->v_north = fdm_state.get_V_north();
 152     net->v_east = fdm_state.get_V_east();
 153     net->v_down = fdm_state.get_V_down();
 154     net->v_body_u = fdm_state.get_uBody();
 155     net->v_body_v = fdm_state.get_vBody();
 156     net->v_body_w = fdm_state.get_wBody();
 157
 158     net->A_X_pilot = fdm_state.get_A_X_pilot();
 159     net->A_Y_pilot = fdm_state.get_A_Y_pilot();
 160     net->A_Z_pilot = fdm_state.get_A_Z_pilot();
 161
 162     net->stall_warning = fgGetDouble("/sim/alarms/stall-warning", 0.0);
 163     net->slip_deg
 164       = fgGetDouble("/instrumentation/slip-skid-ball/indicated-slip-skid");
 165
 166     // Engine parameters
 167     net->num_engines = FGNetFDM::FG_MAX_ENGINES;
 168     for ( i = 0; i < net->num_engines; ++i ) {
 169         SGPropertyNode *node = fgGetNode("engines/engine", i, true);
 170         if ( node->getBoolValue( "running" ) ) {
 171             net->eng_state[i] = 2;
 172         } else if ( node->getBoolValue( "cranking" ) ) {
 173             net->eng_state[i] = 1;
 174         } else {
 175             net->eng_state[i] = 0;
 176         }
 177         net->rpm[i] = node->getDoubleValue( "rpm" );
 178         net->fuel_flow[i] = node->getDoubleValue( "fuel-flow-gph" );
 179         net->fuel_px[i] = node->getDoubleValue( "fuel-px-psi" );
 180         net->egt[i] = node->getDoubleValue( "egt-degf" );
 181         // cout << "egt = " << aero->EGT << endl;
 182         net->cht[i] = node->getDoubleValue( "cht-degf" );
 183         net->mp_osi[i] = node->getDoubleValue( "mp-osi" );
 184         net->tit[i] = node->getDoubleValue( "tit" );
 185         net->oil_temp[i] = node->getDoubleValue( "oil-temperature-degf" );
 186         net->oil_px[i] = node->getDoubleValue( "oil-pressure-psi" );
 187     }
 188
 189     // Consumables
 190     net->num_tanks = FGNetFDM::FG_MAX_TANKS;
 191     for ( i = 0; i < net->num_tanks; ++i ) {
 192         SGPropertyNode *node = fgGetNode("/consumables/fuel/tank", i, true);
 193         net->fuel_quantity[i] = node->getDoubleValue("level-gal_us");
 194     }
 195
 196     // Gear and flaps
 197     net->num_wheels = FGNetFDM::FG_MAX_WHEELS;
 198     for (i = 0; i < net->num_wheels; ++i ) {
 199         SGPropertyNode *node = fgGetNode("/gear/gear", i, true);
 200         net->wow[i] = node->getIntValue("wow");
 201         net->gear_pos[i] = node->getDoubleValue("position-norm");
 202         net->gear_steer[i] = node->getDoubleValue("steering-norm");
 203         net->gear_compression[i] = node->getDoubleValue("compression-norm");
 204     }
 205
 206     // the following really aren't used in this context
 207     net->cur_time = globals->get_time_params()->get_cur_time();
 208     net->warp = globals->get_warp();
 209     net->visibility = fgGetDouble("/environment/visibility-m");
 210
 211     // Control surface positions
 212     SGPropertyNode *node = fgGetNode("/surface-positions", true);
 213     net->elevator = node->getDoubleValue( "elevator-pos-norm" );
 214     net->elevator_trim_tab
 215         = node->getDoubleValue( "elevator-trim-tab-pos-norm" );
 216     // FIXME: CLO 10/28/04 - This really should be separated out into 2 values
 217     net->left_flap = node->getDoubleValue( "flap-pos-norm" );
 218     net->right_flap = node->getDoubleValue( "flap-pos-norm" );
 219     net->left_aileron = node->getDoubleValue( "left-aileron-pos-norm" );
 220     net->right_aileron = node->getDoubleValue( "right-aileron-pos-norm" );
 221     net->rudder = node->getDoubleValue( "rudder-pos-norm" );
 222     net->nose_wheel = node->getDoubleValue( "nose-wheel-pos-norm" );
 223     net->speedbrake = node->getDoubleValue( "speedbrake-pos-norm" );
 224     net->spoilers = node->getDoubleValue( "spoilers-pos-norm" );
 225
 226     if ( net_byte_order ) {
 227         // Convert the net buffer to network format
 228         net->version = htonl(net->version);
 229
 230         htond(net->longitude);
 231         htond(net->latitude);
 232         htond(net->altitude);
 233         htonf(net->agl);
 234         htonf(net->phi);
 235         htonf(net->theta);
 236         htonf(net->psi);
 237         htonf(net->alpha);
 238         htonf(net->beta);
 239
 240         htonf(net->phidot);
 241         htonf(net->thetadot);
 242         htonf(net->psidot);
 243         htonf(net->vcas);
 244         htonf(net->climb_rate);
 245         htonf(net->v_north);
 246         htonf(net->v_east);
 247         htonf(net->v_down);
 248         htonf(net->v_body_u);
 249         htonf(net->v_body_v);
 250         htonf(net->v_body_w);
 251
 252         htonf(net->A_X_pilot);
 253         htonf(net->A_Y_pilot);
 254         htonf(net->A_Z_pilot);
 255
 256         htonf(net->stall_warning);
 257         htonf(net->slip_deg);
 258
 259         for ( i = 0; i < net->num_engines; ++i ) {
 260             net->eng_state[i] = htonl(net->eng_state[i]);
 261             htonf(net->rpm[i]);
 262             htonf(net->fuel_flow[i]);
 263             htonf(net->fuel_px[i]);
 264             htonf(net->egt[i]);
 265             htonf(net->cht[i]);
 266             htonf(net->mp_osi[i]);
 267             htonf(net->tit[i]);
 268             htonf(net->oil_temp[i]);
 269             htonf(net->oil_px[i]);
 270         }
 271         net->num_engines = htonl(net->num_engines);
 272
 273         for ( i = 0; i < net->num_tanks; ++i ) {
 274             htonf(net->fuel_quantity[i]);
 275         }
 276         net->num_tanks = htonl(net->num_tanks);
 277
 278         for ( i = 0; i < net->num_wheels; ++i ) {
 279             net->wow[i] = htonl(net->wow[i]);
 280             htonf(net->gear_pos[i]);
 281             htonf(net->gear_steer[i]);
 282             htonf(net->gear_compression[i]);
 283         }
 284         net->num_wheels = htonl(net->num_wheels);
 285
 286         net->cur_time = htonl( net->cur_time );
 287         net->warp = htonl( net->warp );
 288         htonf(net->visibility);
 289
 290         htonf(net->elevator);
 291         htonf(net->elevator_trim_tab);
 292         htonf(net->left_flap);
 293         htonf(net->right_flap);
 294         htonf(net->left_aileron);
 295         htonf(net->right_aileron);
 296         htonf(net->rudder);
 297         htonf(net->nose_wheel);
 298         htonf(net->speedbrake);
 299         htonf(net->spoilers);
 300     }
 301 }
 302
 303
 304 void FGNetFDM2Props( FGNetFDM *net, bool net_byte_order ) {
 305     unsigned int i;
 306     FlightProperties fdm_state;
 307
 308     if ( net_byte_order ) {
 309         // Convert to the net buffer from network format
 310         net->version = ntohl(net->version);
 311
 312         htond(net->longitude);
 313         htond(net->latitude);
 314         htond(net->altitude);
 315         htonf(net->agl);
 316         htonf(net->phi);
 317         htonf(net->theta);
 318         htonf(net->psi);
 319         htonf(net->alpha);
 320         htonf(net->beta);
 321
 322         htonf(net->phidot);
 323         htonf(net->thetadot);
 324         htonf(net->psidot);
 325         htonf(net->vcas);
 326         htonf(net->climb_rate);
 327         htonf(net->v_north);
 328         htonf(net->v_east);
 329         htonf(net->v_down);
 330         htonf(net->v_body_u);
 331         htonf(net->v_body_v);
 332         htonf(net->v_body_w);
 333
 334         htonf(net->A_X_pilot);
 335         htonf(net->A_Y_pilot);
 336         htonf(net->A_Z_pilot);
 337
 338         htonf(net->stall_warning);
 339         htonf(net->slip_deg);
 340
 341         net->num_engines = htonl(net->num_engines);
 342         for ( i = 0; i < net->num_engines; ++i ) {
 343             net->eng_state[i] = htonl(net->eng_state[i]);
 344             htonf(net->rpm[i]);
 345             htonf(net->fuel_flow[i]);
 346             htonf(net->fuel_px[i]);
 347             htonf(net->egt[i]);
 348             htonf(net->cht[i]);
 349             htonf(net->mp_osi[i]);
 350             htonf(net->tit[i]);
 351             htonf(net->oil_temp[i]);
 352             htonf(net->oil_px[i]);
 353         }
 354
 355         net->num_tanks = htonl(net->num_tanks);
 356         for ( i = 0; i < net->num_tanks; ++i ) {
 357             htonf(net->fuel_quantity[i]);
 358         }
 359
 360         net->num_wheels = htonl(net->num_wheels);
 361         for ( i = 0; i < net->num_wheels; ++i ) {
 362             net->wow[i] = htonl(net->wow[i]);
 363             htonf(net->gear_pos[i]);
 364             htonf(net->gear_steer[i]);
 365             htonf(net->gear_compression[i]);
 366         }
 367
 368         net->cur_time = htonl(net->cur_time);
 369         net->warp = ntohl(net->warp);
 370         htonf(net->visibility);
 371
 372         htonf(net->elevator);
 373         htonf(net->elevator_trim_tab);
 374         htonf(net->left_flap);
 375         htonf(net->right_flap);
 376         htonf(net->left_aileron);
 377         htonf(net->right_aileron);
 378         htonf(net->rudder);
 379         htonf(net->nose_wheel);
 380         htonf(net->speedbrake);
 381         htonf(net->spoilers);
 382     }
 383
 384     if ( net->version == FG_NET_FDM_VERSION ) {
 385         // cout << "pos = " << net->longitude << " " << net->latitude << endl;
 386         // cout << "sea level rad = " << fdm_state.get_Sea_level_radius()
 387         //      << endl;
 388
 389       fdm_state.set_Latitude(net->latitude);
 390         fdm_state.set_Longitude(net->longitude);
 391         fdm_state.set_Altitude(net->altitude * SG_METER_TO_FEET);
 392
 393         if ( net->agl > -9000 ) {
 394             fdm_state.set_Altitude_AGL( net->agl * SG_METER_TO_FEET );
 395         } else {
 396             double agl_m = net->altitude
 397               - fdm_state.get_Runway_altitude_m();
 398             fdm_state.set_Altitude_AGL( agl_m * SG_METER_TO_FEET );
 399         }
 400         fdm_state.set_Euler_Angles( net->phi,
 401                                           net->theta,
 402                                           net->psi );
 403         fdm_state.set_Alpha( net->alpha );
 404         fdm_state.set_Beta( net->beta );
 405         fdm_state.set_Euler_Rates( net->phidot,
 406                                          net->thetadot,
 407                                          net->psidot );
 408         fdm_state.set_V_calibrated_kts( net->vcas );
 409         fdm_state.set_Climb_Rate( net->climb_rate );
 410         fdm_state.set_Velocities_Local( net->v_north,
 411                                               net->v_east,
 412                                               net->v_down );
 413         fdm_state.set_Velocities_Body( net->v_body_u,
 414                                                   net->v_body_v,
 415                                                   net->v_body_w );
 416
 417         fdm_state.set_Accels_Pilot_Body( net->A_X_pilot,
 418                                                net->A_Y_pilot,
 419                                                net->A_Z_pilot );
 420
 421         fgSetDouble( "/sim/alarms/stall-warning", net->stall_warning );
 422         fgSetDouble( "/instrumentation/slip-skid-ball/indicated-slip-skid",
 423                      net->slip_deg );
 424         fgSetBool( "/instrumentation/slip-skid-ball/override", true );
 425
 426         for ( i = 0; i < net->num_engines; ++i ) {
 427             SGPropertyNode *node = fgGetNode( "engines/engine", i, true );
 428
 429             // node->setBoolValue("running", t->isRunning());
 430             // node->setBoolValue("cranking", t->isCranking());
 431
 432             // cout << net->eng_state[i] << endl;
 433             if ( net->eng_state[i] == 0 ) {
 434                 node->setBoolValue( "cranking", false );
 435                 node->setBoolValue( "running", false );
 436             } else if ( net->eng_state[i] == 1 ) {
 437                 node->setBoolValue( "cranking", true );
 438                 node->setBoolValue( "running", false );
 439             } else if ( net->eng_state[i] == 2 ) {
 440                 node->setBoolValue( "cranking", false );
 441                 node->setBoolValue( "running", true );
 442             }
 443
 444             node->setDoubleValue( "rpm", net->rpm[i] );
 445             node->setDoubleValue( "fuel-flow-gph", net->fuel_flow[i] );
 446             node->setDoubleValue( "fuel-px-psi", net->fuel_px[i] );
 447             node->setDoubleValue( "egt-degf", net->egt[i] );
 448             node->setDoubleValue( "cht-degf", net->cht[i] );
 449             node->setDoubleValue( "mp-osi", net->mp_osi[i] );
 450             node->setDoubleValue( "tit", net->tit[i] );
 451             node->setDoubleValue( "oil-temperature-degf", net->oil_temp[i] );
 452             node->setDoubleValue( "oil-pressure-psi", net->oil_px[i] );
 453         }
 454
 455         for (i = 0; i < net->num_tanks; ++i ) {
 456             SGPropertyNode * node
 457                 = fgGetNode("/consumables/fuel/tank", i, true);
 458             node->setDoubleValue("level-gal_us", net->fuel_quantity[i] );
 459         }
 460
 461         for (i = 0; i < net->num_wheels; ++i ) {
 462             SGPropertyNode * node = fgGetNode("/gear/gear", i, true);
 463             node->setDoubleValue("wow", net->wow[i] );
 464             node->setDoubleValue("position-norm", net->gear_pos[i] );
 465             node->setDoubleValue("steering-norm", net->gear_steer[i] );
 466             node->setDoubleValue("compression-norm", net->gear_compression[i] );
 467         }
 468
 469         /* these are ignored for now  ... */
 470         /*
 471         if ( net->cur_time ) {
 472             fgSetLong("/sim/time/cur-time-override", net->cur_time);
 473         }
 474
 475         globals->set_warp( net->warp );
 476         last_warp = net->warp;
 477         */
 478
 479         SGPropertyNode *node = fgGetNode("/surface-positions", true);
 480         node->setDoubleValue("elevator-pos-norm", net->elevator);
 481         node->setDoubleValue("elevator-trim-tab-pos-norm",
 482                              net->elevator_trim_tab);
 483         // FIXME: CLO 10/28/04 - This really should be separated out
 484         // into 2 values
 485         node->setDoubleValue("flap-pos-norm", net->left_flap);
 486         node->setDoubleValue("flap-pos-norm", net->right_flap);
 487         node->setDoubleValue("left-aileron-pos-norm", net->left_aileron);
 488         node->setDoubleValue("right-aileron-pos-norm", net->right_aileron);
 489         node->setDoubleValue("rudder-pos-norm", net->rudder);
 490         node->setDoubleValue("nose-wheel-pos-norm", net->nose_wheel);
 491         node->setDoubleValue("speedbrake-pos-norm", net->speedbrake);
 492         node->setDoubleValue("spoilers-pos-norm", net->spoilers);
 493     } else {
 494         SG_LOG( SG_IO, SG_ALERT,
 495                 "Error: version mismatch in FGNetFDM2Props()" );
 496         SG_LOG( SG_IO, SG_ALERT,
 497                 "\tread " << net->version << " need " << FG_NET_FDM_VERSION );
 498         SG_LOG( SG_IO, SG_ALERT,
 499                 "\tNeeds to upgrade net_fdm.hxx and recompile." );
 500     }
 501 }
 502
 503
 504 // process work for this port
 505 bool FGNativeFDM::process() {
 506     SGIOChannel *io = get_io_channel();
 507     int length = sizeof(buf);
 508
 509     if ( get_direction() == SG_IO_OUT ) {
 510
 511         FGProps2NetFDM( &buf );
 512         if ( ! io->write( (char *)(& buf), length ) ) {
 513             SG_LOG( SG_IO, SG_ALERT, "Error writing data." );
 514             return false;
 515         }
 516     } else if ( get_direction() == SG_IO_IN ) {
 517         if ( io->get_type() == sgFileType ) {
 518             if ( io->read( (char *)(& buf), length ) == length ) {
 519                 SG_LOG( SG_IO, SG_DEBUG, "Success reading data." );
 520                 FGNetFDM2Props( &buf );
 521             }
 522         } else {
 523             int result;
 524             result = io->read( (char *)(& buf), length );
 525             while ( result == length ) {
 526                 if ( result == length ) {
 527                     SG_LOG( SG_IO, SG_DEBUG, "  Success reading data." );
 528                     FGNetFDM2Props( &buf );
 529                 }
 530                 result = io->read( (char *)(& buf), length );
 531             }
 532         }
 533     }
 534
 535     return true;
 536 }
 537
 538
 539 // close the channel
 540 bool FGNativeFDM::close() {
 541     SGIOChannel *io = get_io_channel();
 542
 543     set_enabled( false );
 544
 545     if ( ! io->close() ) {
 546         return false;
 547     }
 548
 549     return true;
 550 }