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 // Float version
  74 static void htonf (float &x)
  75 {
  76     if ( sgIsLittleEndian() ) {
  77         int    *Float_Overlay;
  78         int     Holding_Buffer;
  79
  80         Float_Overlay = (int *) &x;
  81         Holding_Buffer = Float_Overlay [0];
  82
  83         Float_Overlay [0] = htonl (Holding_Buffer);
  84     } else {
  85         return;
  86     }
  87 }
  88
  89
  90 FGNativeFDM::FGNativeFDM() {
  91 }
  92
  93 FGNativeFDM::~FGNativeFDM() {
  94 }
  95
  96
  97 // open hailing frequencies
  98 bool FGNativeFDM::open() {
  99     if ( is_enabled() ) {
 100         SG_LOG( SG_IO, SG_ALERT, "This shouldn't happen, but the channel "
 101                 << "is already in use, ignoring" );
 102         return false;
 103     }
 104
 105     SGIOChannel *io = get_io_channel();
 106
 107     if ( ! io->open( get_direction() ) ) {
 108         SG_LOG( SG_IO, SG_ALERT, "Error opening channel communication layer." );
 109         return false;
 110     }
 111
 112     set_enabled( true );
 113
 114     // Is this really needed here ????
 115     cur_fdm_state->_set_Sea_level_radius( SG_EQUATORIAL_RADIUS_FT );
 116
 117     return true;
 118 }
 119
 120
 121 void FGProps2NetFDM( FGNetFDM *net, bool net_byte_order ) {
 122     int i;
 123
 124     // Version sanity checking
 125     net->version = FG_NET_FDM_VERSION;
 126
 127     // Aero parameters
 128     net->longitude = cur_fdm_state->get_Longitude();
 129     net->latitude = cur_fdm_state->get_Latitude();
 130     net->altitude = cur_fdm_state->get_Altitude() * SG_FEET_TO_METER;
 131     net->agl = cur_fdm_state->get_Altitude_AGL() * SG_FEET_TO_METER;
 132     net->phi = cur_fdm_state->get_Phi();
 133     net->theta = cur_fdm_state->get_Theta();
 134     net->psi = cur_fdm_state->get_Psi();
 135     net->phidot = cur_fdm_state->get_Phi_dot_degps() * SG_DEGREES_TO_RADIANS;
 136     net->thetadot = cur_fdm_state->get_Theta_dot_degps()
 137         * SG_DEGREES_TO_RADIANS;
 138     net->psidot = cur_fdm_state->get_Psi_dot_degps() * SG_DEGREES_TO_RADIANS;
 139
 140     net->vcas = cur_fdm_state->get_V_calibrated_kts();
 141     net->climb_rate = cur_fdm_state->get_Climb_Rate();
 142
 143     net->v_north = cur_fdm_state->get_V_north();
 144     net->v_east = cur_fdm_state->get_V_east();
 145     net->v_down = cur_fdm_state->get_V_down();
 146     net->v_wind_body_north = cur_fdm_state->get_uBody();
 147     net->v_wind_body_east = cur_fdm_state->get_vBody();
 148     net->v_wind_body_down = cur_fdm_state->get_wBody();
 149     net->stall_warning = fgGetDouble("/sim/alarms/stall-warning", 0.0);
 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     // Engine parameters
 156     net->num_engines = FGNetFDM::FG_MAX_ENGINES;
 157     for ( i = 0; i < net->num_engines; ++i ) {
 158         SGPropertyNode *node = fgGetNode("engines/engine", i, true);
 159         if ( node->getBoolValue( "running" ) ) {
 160             net->eng_state[0] = 2;
 161         } else if ( node->getBoolValue( "cranking" ) ) {
 162             net->eng_state[0] = 1;
 163         } else {
 164             net->eng_state[0] = 0;
 165         }
 166         net->rpm[i] = node->getDoubleValue( "rpm" );
 167         net->fuel_flow[i] = node->getDoubleValue( "fuel-flow-gph" );
 168         net->EGT[i] = node->getDoubleValue( "egt-degf" );
 169         // cout << "egt = " << aero->EGT << endl;
 170         net->oil_temp[i] = node->getDoubleValue( "oil-temperature-degf" );
 171         net->oil_px[i] = node->getDoubleValue( "oil-pressure-psi" );
 172     }
 173
 174     // Consumables
 175     net->num_tanks = FGNetFDM::FG_MAX_TANKS;
 176     for ( i = 0; i < net->num_tanks; ++i ) {
 177         SGPropertyNode *node = fgGetNode("/consumables/fuel/tank", i, true);
 178         net->fuel_quantity[i] = node->getDoubleValue("level-gal_us");
 179     }
 180
 181     // Gear and flaps
 182     net->num_wheels = FGNetFDM::FG_MAX_WHEELS;
 183     for (i = 0; i < net->num_wheels; ++i ) {
 184         SGPropertyNode *node = fgGetNode("/gear/gear", i, true);
 185         net->wow[i] = node->getDoubleValue("wow");
 186         net->gear_pos[i] = node->getDoubleValue("position-norm");
 187         net->gear_steer[i] = node->getDoubleValue("steering-norm");
 188         net->gear_compression[i] = node->getDoubleValue("compression-norm");
 189     }
 190
 191     // the following really aren't used in this context
 192     net->cur_time = globals->get_time_params()->get_cur_time();
 193     net->warp = globals->get_warp();
 194     net->visibility = fgGetDouble("/environment/visibility-m");
 195
 196     // Control surface positions
 197     SGPropertyNode *node = fgGetNode("/surface-positions", true);
 198     net->elevator = node->getDoubleValue( "elevator-pos-norm" );
 199     net->flaps = node->getDoubleValue( "flap-pos-norm" );
 200     net->left_aileron = node->getDoubleValue( "left-aileron-pos-norm" );
 201     net->right_aileron = node->getDoubleValue( "right-aileron-pos-norm" );
 202     net->rudder = node->getDoubleValue( "rudder-pos-norm" );
 203     net->speedbrake = node->getDoubleValue( "speedbrake-pos-norm" );
 204     net->spoilers = node->getDoubleValue( "spoilers-pos-norm" );
 205
 206     if ( net_byte_order ) {
 207         // Convert the net buffer to network format
 208         net->version = htonl(net->version);
 209
 210         htond(net->longitude);
 211         htond(net->latitude);
 212         htond(net->altitude);
 213         htonf(net->agl);
 214         htonf(net->phi);
 215         htonf(net->theta);
 216         htonf(net->psi);
 217
 218         htonf(net->phidot);
 219         htonf(net->thetadot);
 220         htonf(net->psidot);
 221         htonf(net->vcas);
 222         htonf(net->climb_rate);
 223         htonf(net->v_north);
 224         htonf(net->v_east);
 225         htonf(net->v_down);
 226         htonf(net->v_wind_body_north);
 227         htonf(net->v_wind_body_east);
 228         htonf(net->v_wind_body_down);
 229         htonf(net->stall_warning);
 230
 231         htonf(net->A_X_pilot);
 232         htonf(net->A_Y_pilot);
 233         htonf(net->A_Z_pilot);
 234
 235         for ( i = 0; i < net->num_engines; ++i ) {
 236             htonl(net->eng_state[i]);
 237             htonf(net->rpm[i]);
 238             htonf(net->fuel_flow[i]);
 239             htonf(net->EGT[i]);
 240             htonf(net->oil_temp[i]);
 241             htonf(net->oil_px[i]);
 242         }
 243         net->num_engines = htonl(net->num_engines);
 244
 245         for ( i = 0; i < net->num_tanks; ++i ) {
 246             htonf(net->fuel_quantity[i]);
 247         }
 248         net->num_tanks = htonl(net->num_tanks);
 249
 250         for ( i = 0; i < net->num_wheels; ++i ) {
 251             htonl(net->wow[i]);
 252             htonf(net->gear_pos[i]);
 253             htonf(net->gear_steer[i]);
 254             htonf(net->gear_compression[i]);
 255         }
 256         net->num_wheels = htonl(net->num_wheels);
 257
 258         net->cur_time = htonl( net->cur_time );
 259         net->warp = htonl( net->warp );
 260         htonf(net->visibility);
 261
 262         htonf(net->elevator);
 263         htonf(net->flaps);
 264         htonf(net->left_aileron);
 265         htonf(net->right_aileron);
 266         htonf(net->rudder);
 267         htonf(net->speedbrake);
 268         htonf(net->spoilers);
 269     }
 270 }
 271
 272
 273 void FGNetFDM2Props( FGNetFDM *net, bool net_byte_order ) {
 274     int i;
 275
 276     if ( net_byte_order ) {
 277         // Convert to the net buffer from network format
 278         net->version = ntohl(net->version);
 279
 280         htond(net->longitude);
 281         htond(net->latitude);
 282         htond(net->altitude);
 283         htonf(net->agl);
 284         htonf(net->phi);
 285         htonf(net->theta);
 286         htonf(net->psi);
 287
 288         htonf(net->phidot);
 289         htonf(net->thetadot);
 290         htonf(net->psidot);
 291         htonf(net->vcas);
 292         htonf(net->climb_rate);
 293         htonf(net->v_north);
 294         htonf(net->v_east);
 295         htonf(net->v_down);
 296         htonf(net->v_wind_body_north);
 297         htonf(net->v_wind_body_east);
 298         htonf(net->v_wind_body_down);
 299         htonf(net->stall_warning);
 300
 301         htonf(net->A_X_pilot);
 302         htonf(net->A_Y_pilot);
 303         htonf(net->A_Z_pilot);
 304
 305         net->num_engines = htonl(net->num_engines);
 306         for ( i = 0; i < net->num_engines; ++i ) {
 307             htonl(net->eng_state[i]);
 308             htonf(net->rpm[i]);
 309             htonf(net->fuel_flow[i]);
 310             htonf(net->EGT[i]);
 311             htonf(net->oil_temp[i]);
 312             htonf(net->oil_px[i]);
 313         }
 314
 315         net->num_tanks = htonl(net->num_tanks);
 316         for ( i = 0; i < net->num_tanks; ++i ) {
 317             htonf(net->fuel_quantity[i]);
 318         }
 319
 320         net->num_wheels = htonl(net->num_wheels);
 321         for ( i = 0; i < net->num_wheels; ++i ) {
 322             htonl(net->wow[i]);
 323             htonf(net->gear_pos[i]);
 324             htonf(net->gear_steer[i]);
 325             htonf(net->gear_compression[i]);
 326         }
 327
 328         net->cur_time = ntohl(net->cur_time);
 329         net->warp = ntohl(net->warp);
 330         htonf(net->visibility);
 331
 332         htonf(net->elevator);
 333         htonf(net->flaps);
 334         htonf(net->left_aileron);
 335         htonf(net->right_aileron);
 336         htonf(net->rudder);
 337         htonf(net->speedbrake);
 338         htonf(net->spoilers);
 339     }
 340
 341     if ( net->version == FG_NET_FDM_VERSION ) {
 342         // cout << "pos = " << net->longitude << " " << net->latitude << endl;
 343         // cout << "sea level rad = " << cur_fdm_state->get_Sea_level_radius()
 344         //      << endl;
 345         cur_fdm_state->_updateGeodeticPosition( net->latitude,
 346                                                 net->longitude,
 347                                                 net->altitude
 348                                                   * SG_METER_TO_FEET );
 349         cur_fdm_state->_set_Altitude_AGL( net->agl * SG_METER_TO_FEET );
 350         cur_fdm_state->_set_Euler_Angles( net->phi,
 351                                           net->theta,
 352                                           net->psi );
 353         cur_fdm_state->_set_Euler_Rates( net->phidot,
 354                                          net->thetadot,
 355                                          net->psidot );
 356         cur_fdm_state->_set_V_calibrated_kts( net->vcas );
 357         cur_fdm_state->_set_Climb_Rate( net->climb_rate );
 358         cur_fdm_state->_set_Velocities_Local( net->v_north,
 359                                               net->v_east,
 360                                               net->v_down );
 361         cur_fdm_state->_set_Velocities_Wind_Body( net->v_wind_body_north,
 362                                                   net->v_wind_body_east,
 363                                                   net->v_wind_body_down );
 364
 365         fgSetDouble( "/sim/alarms/stall-warning", net->stall_warning );
 366         cur_fdm_state->_set_Accels_Pilot_Body( net->A_X_pilot,
 367                                                net->A_Y_pilot,
 368                                                net->A_Z_pilot );
 369
 370         for ( i = 0; i < net->num_engines; ++i ) {
 371             SGPropertyNode *node = fgGetNode( "engines/engine", i, true );
 372
 373             // node->setBoolValue("running", t->isRunning());
 374             // node->setBoolValue("cranking", t->isCranking());
 375
 376             // cout << net->eng_state[i] << endl;
 377             if ( net->eng_state[i] == 0 ) {
 378                 node->setBoolValue( "cranking", false );
 379                 node->setBoolValue( "running", false );
 380             } else if ( net->eng_state[i] == 1 ) {
 381                 node->setBoolValue( "cranking", true );
 382                 node->setBoolValue( "running", false );
 383             } else if ( net->eng_state[i] == 2 ) {
 384                 node->setBoolValue( "cranking", false );
 385                 node->setBoolValue( "running", true );
 386             }
 387
 388             node->setDoubleValue( "rpm", net->rpm[i] );
 389             node->setDoubleValue( "fuel-flow-gph", net->fuel_flow[i] );
 390             node->setDoubleValue( "egt-degf", net->EGT[i] );
 391             node->setDoubleValue( "oil-temperature-degf", net->oil_temp[i] );
 392             node->setDoubleValue( "oil-pressure-psi", net->oil_px[i] );
 393         }
 394
 395         for (i = 0; i < net->num_tanks; ++i ) {
 396             SGPropertyNode * node
 397                 = fgGetNode("/consumables/fuel/tank", i, true);
 398             node->setDoubleValue("level-gal_us", net->fuel_quantity[i] );
 399         }
 400
 401         for (i = 0; i < net->num_wheels; ++i ) {
 402             SGPropertyNode * node = fgGetNode("/gear/gear", i, true);
 403             node->setDoubleValue("wow", net->wow[i] );
 404             node->setDoubleValue("position-norm", net->gear_pos[i] );
 405             node->setDoubleValue("steering-norm", net->gear_steer[i] );
 406             node->setDoubleValue("compression-norm", net->gear_compression[i] );
 407         }
 408
 409         /* these are ignored for now  ... */
 410         /*
 411         if ( net->cur_time ) {
 412             fgSetLong("/sim/time/cur-time-override", net->cur_time);
 413         }
 414
 415         globals->set_warp( net->warp );
 416         last_warp = net->warp;
 417         */
 418
 419         SGPropertyNode *node = fgGetNode("/surface-positions", true);
 420         node->setDoubleValue("elevator-pos-norm", net->elevator);
 421         node->setDoubleValue("flap-pos-norm", net->flaps);
 422         node->setDoubleValue("left-aileron-pos-norm", net->left_aileron);
 423         node->setDoubleValue("right-aileron-pos-norm", net->right_aileron);
 424         node->setDoubleValue("rudder-pos-norm", net->rudder);
 425         node->setDoubleValue("speedbrake-pos-norm", net->speedbrake);
 426         node->setDoubleValue("spoilers-pos-norm", net->spoilers);
 427     } else {
 428         SG_LOG( SG_IO, SG_ALERT,
 429                 "Error: version mismatch in FGNetFDM2Props()" );
 430         SG_LOG( SG_IO, SG_ALERT,
 431                 "\tread " << net->version << " need " << FG_NET_FDM_VERSION );
 432         SG_LOG( SG_IO, SG_ALERT,
 433                 "\tNeeds to upgrade net_fdm.hxx and recompile." );
 434     }
 435 }
 436
 437
 438 // process work for this port
 439 bool FGNativeFDM::process() {
 440     SGIOChannel *io = get_io_channel();
 441     int length = sizeof(buf);
 442
 443     if ( get_direction() == SG_IO_OUT ) {
 444         // cout << "size of cur_fdm_state = " << length << endl;
 445         FGProps2NetFDM( &buf );
 446         if ( ! io->write( (char *)(& buf), length ) ) {
 447             SG_LOG( SG_IO, SG_ALERT, "Error writing data." );
 448             return false;
 449         }
 450     } else if ( get_direction() == SG_IO_IN ) {
 451         if ( io->get_type() == sgFileType ) {
 452             if ( io->read( (char *)(& buf), length ) == length ) {
 453                 SG_LOG( SG_IO, SG_DEBUG, "Success reading data." );
 454                 FGNetFDM2Props( &buf );
 455             }
 456         } else {
 457             int result;
 458             result = io->read( (char *)(& buf), length );
 459             while ( result == length ) {
 460                 if ( result == length ) {
 461                     SG_LOG( SG_IO, SG_DEBUG, "  Success reading data." );
 462                     FGNetFDM2Props( &buf );
 463                 }
 464                 result = io->read( (char *)(& buf), length );
 465             }
 466         }
 467     }
 468
 469     return true;
 470 }
 471
 472
 473 // close the channel
 474 bool FGNativeFDM::close() {
 475     SGIOChannel *io = get_io_channel();
 476
 477     set_enabled( false );
 478
 479     if ( ! io->close() ) {
 480         return false;
 481     }
 482
 483     return true;
 484 }