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