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->alpha = cur_fdm_state->get_Alpha();
 137     net->beta = cur_fdm_state->get_Beta();
 138     net->phidot = cur_fdm_state->get_Phi_dot_degps() * SG_DEGREES_TO_RADIANS;
 139     net->thetadot = cur_fdm_state->get_Theta_dot_degps()
 140         * SG_DEGREES_TO_RADIANS;
 141     net->psidot = cur_fdm_state->get_Psi_dot_degps() * SG_DEGREES_TO_RADIANS;
 142
 143     net->vcas = cur_fdm_state->get_V_calibrated_kts();
 144     net->climb_rate = cur_fdm_state->get_Climb_Rate();
 145
 146     net->v_north = cur_fdm_state->get_V_north();
 147     net->v_east = cur_fdm_state->get_V_east();
 148     net->v_down = cur_fdm_state->get_V_down();
 149     net->v_wind_body_north = cur_fdm_state->get_uBody();
 150     net->v_wind_body_east = cur_fdm_state->get_vBody();
 151     net->v_wind_body_down = cur_fdm_state->get_wBody();
 152
 153     net->A_X_pilot = cur_fdm_state->get_A_X_pilot();
 154     net->A_Y_pilot = cur_fdm_state->get_A_Y_pilot();
 155     net->A_Z_pilot = cur_fdm_state->get_A_Z_pilot();
 156
 157     net->stall_warning = fgGetDouble("/sim/alarms/stall-warning", 0.0);
 158     net->slip_deg
 159       = fgGetDouble("/instrumentation/slip-skid-ball/indicated-slip-skid");
 160
 161     // Engine parameters
 162     net->num_engines = FGNetFDM::FG_MAX_ENGINES;
 163     for ( i = 0; i < net->num_engines; ++i ) {
 164         SGPropertyNode *node = fgGetNode("engines/engine", i, true);
 165         if ( node->getBoolValue( "running" ) ) {
 166             net->eng_state[i] = 2;
 167         } else if ( node->getBoolValue( "cranking" ) ) {
 168             net->eng_state[i] = 1;
 169         } else {
 170             net->eng_state[i] = 0;
 171         }
 172         net->rpm[i] = node->getDoubleValue( "rpm" );
 173         net->fuel_flow[i] = node->getDoubleValue( "fuel-flow-gph" );
 174         net->egt[i] = node->getDoubleValue( "egt-degf" );
 175         // cout << "egt = " << aero->EGT << endl;
 176         net->mp_osi[i] = node->getDoubleValue( "mp-osi" );
 177         net->oil_temp[i] = node->getDoubleValue( "oil-temperature-degf" );
 178         net->oil_px[i] = node->getDoubleValue( "oil-pressure-psi" );
 179     }
 180
 181     // Consumables
 182     net->num_tanks = FGNetFDM::FG_MAX_TANKS;
 183     for ( i = 0; i < net->num_tanks; ++i ) {
 184         SGPropertyNode *node = fgGetNode("/consumables/fuel/tank", i, true);
 185         net->fuel_quantity[i] = node->getDoubleValue("level-gal_us");
 186     }
 187
 188     // Gear and flaps
 189     net->num_wheels = FGNetFDM::FG_MAX_WHEELS;
 190     for (i = 0; i < net->num_wheels; ++i ) {
 191         SGPropertyNode *node = fgGetNode("/gear/gear", i, true);
 192         net->wow[i] = node->getDoubleValue("wow");
 193         net->gear_pos[i] = node->getDoubleValue("position-norm");
 194         net->gear_steer[i] = node->getDoubleValue("steering-norm");
 195         net->gear_compression[i] = node->getDoubleValue("compression-norm");
 196     }
 197
 198     // the following really aren't used in this context
 199     net->cur_time = globals->get_time_params()->get_cur_time();
 200     net->warp = globals->get_warp();
 201     net->visibility = fgGetDouble("/environment/visibility-m");
 202
 203     // Control surface positions
 204     SGPropertyNode *node = fgGetNode("/surface-positions", true);
 205     net->elevator = node->getDoubleValue( "elevator-pos-norm" );
 206     net->elevator_trim_tab
 207         = node->getDoubleValue( "elevator-trim-tab-pos-norm" );
 208     net->flaps = node->getDoubleValue( "flap-pos-norm" );
 209     net->left_aileron = node->getDoubleValue( "left-aileron-pos-norm" );
 210     net->right_aileron = node->getDoubleValue( "right-aileron-pos-norm" );
 211     net->rudder = node->getDoubleValue( "rudder-pos-norm" );
 212     net->rudder = node->getDoubleValue( "nose-wheel-pos-norm" );
 213     net->speedbrake = node->getDoubleValue( "speedbrake-pos-norm" );
 214     net->spoilers = node->getDoubleValue( "spoilers-pos-norm" );
 215
 216     if ( net_byte_order ) {
 217         // Convert the net buffer to network format
 218         net->version = htonl(net->version);
 219
 220         htond(net->longitude);
 221         htond(net->latitude);
 222         htond(net->altitude);
 223         htonf(net->agl);
 224         htonf(net->phi);
 225         htonf(net->theta);
 226         htonf(net->psi);
 227         htonf(net->alpha);
 228         htonf(net->beta);
 229
 230         htonf(net->phidot);
 231         htonf(net->thetadot);
 232         htonf(net->psidot);
 233         htonf(net->vcas);
 234         htonf(net->climb_rate);
 235         htonf(net->v_north);
 236         htonf(net->v_east);
 237         htonf(net->v_down);
 238         htonf(net->v_wind_body_north);
 239         htonf(net->v_wind_body_east);
 240         htonf(net->v_wind_body_down);
 241
 242         htonf(net->A_X_pilot);
 243         htonf(net->A_Y_pilot);
 244         htonf(net->A_Z_pilot);
 245
 246         htonf(net->stall_warning);
 247         htonf(net->slip_deg);
 248
 249         for ( i = 0; i < net->num_engines; ++i ) {
 250             net->eng_state[i] = htonl(net->eng_state[i]);
 251             htonf(net->rpm[i]);
 252             htonf(net->fuel_flow[i]);
 253             htonf(net->egt[i]);
 254             htonf(net->mp_osi[i]);
 255             htonf(net->oil_temp[i]);
 256             htonf(net->oil_px[i]);
 257         }
 258         net->num_engines = htonl(net->num_engines);
 259
 260         for ( i = 0; i < net->num_tanks; ++i ) {
 261             htonf(net->fuel_quantity[i]);
 262         }
 263         net->num_tanks = htonl(net->num_tanks);
 264
 265         for ( i = 0; i < net->num_wheels; ++i ) {
 266             net->wow[i] = htonl(net->wow[i]);
 267             htonf(net->gear_pos[i]);
 268             htonf(net->gear_steer[i]);
 269             htonf(net->gear_compression[i]);
 270         }
 271         net->num_wheels = htonl(net->num_wheels);
 272
 273         net->cur_time = htonl( net->cur_time );
 274         net->warp = htonl( net->warp );
 275         htonf(net->visibility);
 276
 277         htonf(net->elevator);
 278         htonf(net->elevator_trim_tab);
 279         htonf(net->flaps);
 280         htonf(net->left_aileron);
 281         htonf(net->right_aileron);
 282         htonf(net->rudder);
 283         htonf(net->nose_wheel);
 284         htonf(net->speedbrake);
 285         htonf(net->spoilers);
 286     }
 287 }
 288
 289
 290 void FGNetFDM2Props( FGNetFDM *net, bool net_byte_order ) {
 291     int i;
 292
 293     if ( net_byte_order ) {
 294         // Convert to the net buffer from network format
 295         net->version = ntohl(net->version);
 296
 297         htond(net->longitude);
 298         htond(net->latitude);
 299         htond(net->altitude);
 300         htonf(net->agl);
 301         htonf(net->phi);
 302         htonf(net->theta);
 303         htonf(net->psi);
 304         htonf(net->alpha);
 305         htonf(net->beta);
 306
 307         htonf(net->phidot);
 308         htonf(net->thetadot);
 309         htonf(net->psidot);
 310         htonf(net->vcas);
 311         htonf(net->climb_rate);
 312         htonf(net->v_north);
 313         htonf(net->v_east);
 314         htonf(net->v_down);
 315         htonf(net->v_wind_body_north);
 316         htonf(net->v_wind_body_east);
 317         htonf(net->v_wind_body_down);
 318
 319         htonf(net->A_X_pilot);
 320         htonf(net->A_Y_pilot);
 321         htonf(net->A_Z_pilot);
 322
 323         htonf(net->stall_warning);
 324         htonf(net->slip_deg);
 325
 326         net->num_engines = htonl(net->num_engines);
 327         for ( i = 0; i < net->num_engines; ++i ) {
 328             net->eng_state[i] = htonl(net->eng_state[i]);
 329             htonf(net->rpm[i]);
 330             htonf(net->fuel_flow[i]);
 331             htonf(net->egt[i]);
 332             htonf(net->mp_osi[i]);
 333             htonf(net->oil_temp[i]);
 334             htonf(net->oil_px[i]);
 335         }
 336
 337         net->num_tanks = htonl(net->num_tanks);
 338         for ( i = 0; i < net->num_tanks; ++i ) {
 339             htonf(net->fuel_quantity[i]);
 340         }
 341
 342         net->num_wheels = htonl(net->num_wheels);
 343         for ( i = 0; i < net->num_wheels; ++i ) {
 344             net->wow[i] = htonl(net->wow[i]);
 345             htonf(net->gear_pos[i]);
 346             htonf(net->gear_steer[i]);
 347             htonf(net->gear_compression[i]);
 348         }
 349
 350         net->cur_time = ntohl(net->cur_time);
 351         net->warp = ntohl(net->warp);
 352         htonf(net->visibility);
 353
 354         htonf(net->elevator);
 355         htonf(net->elevator_trim_tab);
 356         htonf(net->flaps);
 357         htonf(net->left_aileron);
 358         htonf(net->right_aileron);
 359         htonf(net->rudder);
 360         htonf(net->nose_wheel);
 361         htonf(net->speedbrake);
 362         htonf(net->spoilers);
 363     }
 364
 365     if ( net->version == FG_NET_FDM_VERSION ) {
 366         // cout << "pos = " << net->longitude << " " << net->latitude << endl;
 367         // cout << "sea level rad = " << cur_fdm_state->get_Sea_level_radius()
 368         //      << endl;
 369         cur_fdm_state->_updateGeodeticPosition( net->latitude,
 370                                                 net->longitude,
 371                                                 net->altitude
 372                                                   * SG_METER_TO_FEET );
 373         if ( net->agl > -9000 ) {
 374             cur_fdm_state->_set_Altitude_AGL( net->agl * SG_METER_TO_FEET );
 375         } else {
 376             double agl_m
 377               = net->altitude - globals->get_scenery()->get_cur_elev();
 378             cur_fdm_state->_set_Altitude_AGL( agl_m * SG_METER_TO_FEET );
 379         }
 380         cur_fdm_state->_set_Euler_Angles( net->phi,
 381                                           net->theta,
 382                                           net->psi );
 383         cur_fdm_state->_set_Alpha( net->alpha );
 384         cur_fdm_state->_set_Beta( net->beta );
 385         cur_fdm_state->_set_Euler_Rates( net->phidot,
 386                                          net->thetadot,
 387                                          net->psidot );
 388         cur_fdm_state->_set_V_calibrated_kts( net->vcas );
 389         cur_fdm_state->_set_Climb_Rate( net->climb_rate );
 390         cur_fdm_state->_set_Velocities_Local( net->v_north,
 391                                               net->v_east,
 392                                               net->v_down );
 393         cur_fdm_state->_set_Velocities_Wind_Body( net->v_wind_body_north,
 394                                                   net->v_wind_body_east,
 395                                                   net->v_wind_body_down );
 396
 397         cur_fdm_state->_set_Accels_Pilot_Body( net->A_X_pilot,
 398                                                net->A_Y_pilot,
 399                                                net->A_Z_pilot );
 400
 401         fgSetDouble( "/sim/alarms/stall-warning", net->stall_warning );
 402         fgSetDouble( "/instrumentation/slip-skid-ball/indicated-slip-skid",
 403                      net->slip_deg );
 404         fgSetBool( "/instrumentation/slip-skid-ball/override", true );
 405
 406         for ( i = 0; i < net->num_engines; ++i ) {
 407             SGPropertyNode *node = fgGetNode( "engines/engine", i, true );
 408
 409             // node->setBoolValue("running", t->isRunning());
 410             // node->setBoolValue("cranking", t->isCranking());
 411
 412             // cout << net->eng_state[i] << endl;
 413             if ( net->eng_state[i] == 0 ) {
 414                 node->setBoolValue( "cranking", false );
 415                 node->setBoolValue( "running", false );
 416             } else if ( net->eng_state[i] == 1 ) {
 417                 node->setBoolValue( "cranking", true );
 418                 node->setBoolValue( "running", false );
 419             } else if ( net->eng_state[i] == 2 ) {
 420                 node->setBoolValue( "cranking", false );
 421                 node->setBoolValue( "running", true );
 422             }
 423
 424             node->setDoubleValue( "rpm", net->rpm[i] );
 425             node->setDoubleValue( "fuel-flow-gph", net->fuel_flow[i] );
 426             node->setDoubleValue( "egt-degf", net->egt[i] );
 427             node->setDoubleValue( "mp-osi", net->mp_osi[i] );
 428             node->setDoubleValue( "oil-temperature-degf", net->oil_temp[i] );
 429             node->setDoubleValue( "oil-pressure-psi", net->oil_px[i] );
 430         }
 431
 432         for (i = 0; i < net->num_tanks; ++i ) {
 433             SGPropertyNode * node
 434                 = fgGetNode("/consumables/fuel/tank", i, true);
 435             node->setDoubleValue("level-gal_us", net->fuel_quantity[i] );
 436         }
 437
 438         for (i = 0; i < net->num_wheels; ++i ) {
 439             SGPropertyNode * node = fgGetNode("/gear/gear", i, true);
 440             node->setDoubleValue("wow", net->wow[i] );
 441             node->setDoubleValue("position-norm", net->gear_pos[i] );
 442             node->setDoubleValue("steering-norm", net->gear_steer[i] );
 443             node->setDoubleValue("compression-norm", net->gear_compression[i] );
 444         }
 445
 446         /* these are ignored for now  ... */
 447         /*
 448         if ( net->cur_time ) {
 449             fgSetLong("/sim/time/cur-time-override", net->cur_time);
 450         }
 451
 452         globals->set_warp( net->warp );
 453         last_warp = net->warp;
 454         */
 455
 456         SGPropertyNode *node = fgGetNode("/surface-positions", true);
 457         node->setDoubleValue("elevator-pos-norm", net->elevator);
 458         node->setDoubleValue("elevator-trim-tab-pos-norm",
 459                              net->elevator_trim_tab);
 460         node->setDoubleValue("flap-pos-norm", net->flaps);
 461         node->setDoubleValue("left-aileron-pos-norm", net->left_aileron);
 462         node->setDoubleValue("right-aileron-pos-norm", net->right_aileron);
 463         node->setDoubleValue("rudder-pos-norm", net->rudder);
 464         node->setDoubleValue("nose-wheel-pos-norm", net->nose_wheel);
 465         node->setDoubleValue("speedbrake-pos-norm", net->speedbrake);
 466         node->setDoubleValue("spoilers-pos-norm", net->spoilers);
 467     } else {
 468         SG_LOG( SG_IO, SG_ALERT,
 469                 "Error: version mismatch in FGNetFDM2Props()" );
 470         SG_LOG( SG_IO, SG_ALERT,
 471                 "\tread " << net->version << " need " << FG_NET_FDM_VERSION );
 472         SG_LOG( SG_IO, SG_ALERT,
 473                 "\tNeeds to upgrade net_fdm.hxx and recompile." );
 474     }
 475 }
 476
 477
 478 // process work for this port
 479 bool FGNativeFDM::process() {
 480     SGIOChannel *io = get_io_channel();
 481     int length = sizeof(buf);
 482
 483     if ( get_direction() == SG_IO_OUT ) {
 484         // cout << "size of cur_fdm_state = " << length << endl;
 485         FGProps2NetFDM( &buf );
 486         if ( ! io->write( (char *)(& buf), length ) ) {
 487             SG_LOG( SG_IO, SG_ALERT, "Error writing data." );
 488             return false;
 489         }
 490     } else if ( get_direction() == SG_IO_IN ) {
 491         if ( io->get_type() == sgFileType ) {
 492             if ( io->read( (char *)(& buf), length ) == length ) {
 493                 SG_LOG( SG_IO, SG_DEBUG, "Success reading data." );
 494                 FGNetFDM2Props( &buf );
 495             }
 496         } else {
 497             int result;
 498             result = io->read( (char *)(& buf), length );
 499             while ( result == length ) {
 500                 if ( result == length ) {
 501                     SG_LOG( SG_IO, SG_DEBUG, "  Success reading data." );
 502                     FGNetFDM2Props( &buf );
 503                 }
 504                 result = io->read( (char *)(& buf), length );
 505             }
 506         }
 507     }
 508
 509     return true;
 510 }
 511
 512
 513 // close the channel
 514 bool FGNativeFDM::close() {
 515     SGIOChannel *io = get_io_channel();
 516
 517     set_enabled( false );
 518
 519     if ( ! io->close() ) {
 520         return false;
 521     }
 522
 523     return true;
 524 }