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/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     unsigned 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->fuel_px[i] = node->getDoubleValue( "fuel-px-psi" );
 175         net->egt[i] = node->getDoubleValue( "egt-degf" );
 176         // cout << "egt = " << aero->EGT << endl;
 177         net->cht[i] = node->getDoubleValue( "cht-degf" );
 178         net->mp_osi[i] = node->getDoubleValue( "mp-osi" );
 179         net->tit[i] = node->getDoubleValue( "tit" );
 180         net->oil_temp[i] = node->getDoubleValue( "oil-temperature-degf" );
 181         net->oil_px[i] = node->getDoubleValue( "oil-pressure-psi" );
 182     }
 183
 184     // Consumables
 185     net->num_tanks = FGNetFDM::FG_MAX_TANKS;
 186     for ( i = 0; i < net->num_tanks; ++i ) {
 187         SGPropertyNode *node = fgGetNode("/consumables/fuel/tank", i, true);
 188         net->fuel_quantity[i] = node->getDoubleValue("level-gal_us");
 189     }
 190
 191     // Gear and flaps
 192     net->num_wheels = FGNetFDM::FG_MAX_WHEELS;
 193     for (i = 0; i < net->num_wheels; ++i ) {
 194         SGPropertyNode *node = fgGetNode("/gear/gear", i, true);
 195         net->wow[i] = node->getIntValue("wow");
 196         net->gear_pos[i] = node->getDoubleValue("position-norm");
 197         net->gear_steer[i] = node->getDoubleValue("steering-norm");
 198         net->gear_compression[i] = node->getDoubleValue("compression-norm");
 199     }
 200
 201     // the following really aren't used in this context
 202     net->cur_time = globals->get_time_params()->get_cur_time();
 203     net->warp = globals->get_warp();
 204     net->visibility = fgGetDouble("/environment/visibility-m");
 205
 206     // Control surface positions
 207     SGPropertyNode *node = fgGetNode("/surface-positions", true);
 208     net->elevator = node->getDoubleValue( "elevator-pos-norm" );
 209     net->elevator_trim_tab
 210         = node->getDoubleValue( "elevator-trim-tab-pos-norm" );
 211     // FIXME: CLO 10/28/04 - This really should be separated out into 2 values
 212     net->left_flap = node->getDoubleValue( "flap-pos-norm" );
 213     net->right_flap = node->getDoubleValue( "flap-pos-norm" );
 214     net->left_aileron = node->getDoubleValue( "left-aileron-pos-norm" );
 215     net->right_aileron = node->getDoubleValue( "right-aileron-pos-norm" );
 216     net->rudder = node->getDoubleValue( "rudder-pos-norm" );
 217     net->rudder = node->getDoubleValue( "nose-wheel-pos-norm" );
 218     net->speedbrake = node->getDoubleValue( "speedbrake-pos-norm" );
 219     net->spoilers = node->getDoubleValue( "spoilers-pos-norm" );
 220
 221     if ( net_byte_order ) {
 222         // Convert the net buffer to network format
 223         net->version = htonl(net->version);
 224
 225         htond(net->longitude);
 226         htond(net->latitude);
 227         htond(net->altitude);
 228         htonf(net->agl);
 229         htonf(net->phi);
 230         htonf(net->theta);
 231         htonf(net->psi);
 232         htonf(net->alpha);
 233         htonf(net->beta);
 234
 235         htonf(net->phidot);
 236         htonf(net->thetadot);
 237         htonf(net->psidot);
 238         htonf(net->vcas);
 239         htonf(net->climb_rate);
 240         htonf(net->v_north);
 241         htonf(net->v_east);
 242         htonf(net->v_down);
 243         htonf(net->v_wind_body_north);
 244         htonf(net->v_wind_body_east);
 245         htonf(net->v_wind_body_down);
 246
 247         htonf(net->A_X_pilot);
 248         htonf(net->A_Y_pilot);
 249         htonf(net->A_Z_pilot);
 250
 251         htonf(net->stall_warning);
 252         htonf(net->slip_deg);
 253
 254         for ( i = 0; i < net->num_engines; ++i ) {
 255             net->eng_state[i] = htonl(net->eng_state[i]);
 256             htonf(net->rpm[i]);
 257             htonf(net->fuel_flow[i]);
 258             htonf(net->fuel_px[i]);
 259             htonf(net->egt[i]);
 260             htonf(net->cht[i]);
 261             htonf(net->mp_osi[i]);
 262             htonf(net->tit[i]);
 263             htonf(net->oil_temp[i]);
 264             htonf(net->oil_px[i]);
 265         }
 266         net->num_engines = htonl(net->num_engines);
 267
 268         for ( i = 0; i < net->num_tanks; ++i ) {
 269             htonf(net->fuel_quantity[i]);
 270         }
 271         net->num_tanks = htonl(net->num_tanks);
 272
 273         for ( i = 0; i < net->num_wheels; ++i ) {
 274             net->wow[i] = htonl(net->wow[i]);
 275             htonf(net->gear_pos[i]);
 276             htonf(net->gear_steer[i]);
 277             htonf(net->gear_compression[i]);
 278         }
 279         net->num_wheels = htonl(net->num_wheels);
 280
 281         net->cur_time = htonl( net->cur_time );
 282         net->warp = htonl( net->warp );
 283         htonf(net->visibility);
 284
 285         htonf(net->elevator);
 286         htonf(net->elevator_trim_tab);
 287         htonf(net->left_flap);
 288         htonf(net->right_flap);
 289         htonf(net->left_aileron);
 290         htonf(net->right_aileron);
 291         htonf(net->rudder);
 292         htonf(net->nose_wheel);
 293         htonf(net->speedbrake);
 294         htonf(net->spoilers);
 295     }
 296 }
 297
 298
 299 void FGNetFDM2Props( FGNetFDM *net, bool net_byte_order ) {
 300     unsigned int i;
 301
 302     if ( net_byte_order ) {
 303         // Convert to the net buffer from network format
 304         net->version = ntohl(net->version);
 305
 306         htond(net->longitude);
 307         htond(net->latitude);
 308         htond(net->altitude);
 309         htonf(net->agl);
 310         htonf(net->phi);
 311         htonf(net->theta);
 312         htonf(net->psi);
 313         htonf(net->alpha);
 314         htonf(net->beta);
 315
 316         htonf(net->phidot);
 317         htonf(net->thetadot);
 318         htonf(net->psidot);
 319         htonf(net->vcas);
 320         htonf(net->climb_rate);
 321         htonf(net->v_north);
 322         htonf(net->v_east);
 323         htonf(net->v_down);
 324         htonf(net->v_wind_body_north);
 325         htonf(net->v_wind_body_east);
 326         htonf(net->v_wind_body_down);
 327
 328         htonf(net->A_X_pilot);
 329         htonf(net->A_Y_pilot);
 330         htonf(net->A_Z_pilot);
 331
 332         htonf(net->stall_warning);
 333         htonf(net->slip_deg);
 334
 335         net->num_engines = htonl(net->num_engines);
 336         for ( i = 0; i < net->num_engines; ++i ) {
 337             net->eng_state[i] = htonl(net->eng_state[i]);
 338             htonf(net->rpm[i]);
 339             htonf(net->fuel_flow[i]);
 340             htonf(net->fuel_px[i]);
 341             htonf(net->egt[i]);
 342             htonf(net->cht[i]);
 343             htonf(net->mp_osi[i]);
 344             htonf(net->tit[i]);
 345             htonf(net->oil_temp[i]);
 346             htonf(net->oil_px[i]);
 347         }
 348
 349         net->num_tanks = htonl(net->num_tanks);
 350         for ( i = 0; i < net->num_tanks; ++i ) {
 351             htonf(net->fuel_quantity[i]);
 352         }
 353
 354         net->num_wheels = htonl(net->num_wheels);
 355         for ( i = 0; i < net->num_wheels; ++i ) {
 356             net->wow[i] = htonl(net->wow[i]);
 357             htonf(net->gear_pos[i]);
 358             htonf(net->gear_steer[i]);
 359             htonf(net->gear_compression[i]);
 360         }
 361
 362         net->cur_time = htonl(net->cur_time);
 363         net->warp = ntohl(net->warp);
 364         htonf(net->visibility);
 365
 366         htonf(net->elevator);
 367         htonf(net->elevator_trim_tab);
 368         htonf(net->left_flap);
 369         htonf(net->right_flap);
 370         htonf(net->left_aileron);
 371         htonf(net->right_aileron);
 372         htonf(net->rudder);
 373         htonf(net->nose_wheel);
 374         htonf(net->speedbrake);
 375         htonf(net->spoilers);
 376     }
 377
 378     if ( net->version == FG_NET_FDM_VERSION ) {
 379         // cout << "pos = " << net->longitude << " " << net->latitude << endl;
 380         // cout << "sea level rad = " << cur_fdm_state->get_Sea_level_radius()
 381         //      << endl;
 382         cur_fdm_state->_updateGeodeticPosition( net->latitude,
 383                                                 net->longitude,
 384                                                 net->altitude
 385                                                   * SG_METER_TO_FEET );
 386         if ( net->agl > -9000 ) {
 387             cur_fdm_state->_set_Altitude_AGL( net->agl * SG_METER_TO_FEET );
 388         } else {
 389             double agl_m = net->altitude
 390               - cur_fdm_state->get_Runway_altitude_m();
 391             cur_fdm_state->_set_Altitude_AGL( agl_m * SG_METER_TO_FEET );
 392         }
 393         cur_fdm_state->_set_Euler_Angles( net->phi,
 394                                           net->theta,
 395                                           net->psi );
 396         cur_fdm_state->_set_Alpha( net->alpha );
 397         cur_fdm_state->_set_Beta( net->beta );
 398         cur_fdm_state->_set_Euler_Rates( net->phidot,
 399                                          net->thetadot,
 400                                          net->psidot );
 401         cur_fdm_state->_set_V_calibrated_kts( net->vcas );
 402         cur_fdm_state->_set_Climb_Rate( net->climb_rate );
 403         cur_fdm_state->_set_Velocities_Local( net->v_north,
 404                                               net->v_east,
 405                                               net->v_down );
 406         cur_fdm_state->_set_Velocities_Wind_Body( net->v_wind_body_north,
 407                                                   net->v_wind_body_east,
 408                                                   net->v_wind_body_down );
 409
 410         cur_fdm_state->_set_Accels_Pilot_Body( net->A_X_pilot,
 411                                                net->A_Y_pilot,
 412                                                net->A_Z_pilot );
 413
 414         fgSetDouble( "/sim/alarms/stall-warning", net->stall_warning );
 415         fgSetDouble( "/instrumentation/slip-skid-ball/indicated-slip-skid",
 416                      net->slip_deg );
 417         fgSetBool( "/instrumentation/slip-skid-ball/override", true );
 418
 419         for ( i = 0; i < net->num_engines; ++i ) {
 420             SGPropertyNode *node = fgGetNode( "engines/engine", i, true );
 421
 422             // node->setBoolValue("running", t->isRunning());
 423             // node->setBoolValue("cranking", t->isCranking());
 424
 425             // cout << net->eng_state[i] << endl;
 426             if ( net->eng_state[i] == 0 ) {
 427                 node->setBoolValue( "cranking", false );
 428                 node->setBoolValue( "running", false );
 429             } else if ( net->eng_state[i] == 1 ) {
 430                 node->setBoolValue( "cranking", true );
 431                 node->setBoolValue( "running", false );
 432             } else if ( net->eng_state[i] == 2 ) {
 433                 node->setBoolValue( "cranking", false );
 434                 node->setBoolValue( "running", true );
 435             }
 436
 437             node->setDoubleValue( "rpm", net->rpm[i] );
 438             node->setDoubleValue( "fuel-flow-gph", net->fuel_flow[i] );
 439             node->setDoubleValue( "fuel-px-psi", net->fuel_px[i] );
 440             node->setDoubleValue( "egt-degf", net->egt[i] );
 441             node->setDoubleValue( "cht-degf", net->cht[i] );
 442             node->setDoubleValue( "mp-osi", net->mp_osi[i] );
 443             node->setDoubleValue( "tit", net->tit[i] );
 444             node->setDoubleValue( "oil-temperature-degf", net->oil_temp[i] );
 445             node->setDoubleValue( "oil-pressure-psi", net->oil_px[i] );
 446         }
 447
 448         for (i = 0; i < net->num_tanks; ++i ) {
 449             SGPropertyNode * node
 450                 = fgGetNode("/consumables/fuel/tank", i, true);
 451             node->setDoubleValue("level-gal_us", net->fuel_quantity[i] );
 452         }
 453
 454         for (i = 0; i < net->num_wheels; ++i ) {
 455             SGPropertyNode * node = fgGetNode("/gear/gear", i, true);
 456             node->setDoubleValue("wow", net->wow[i] );
 457             node->setDoubleValue("position-norm", net->gear_pos[i] );
 458             node->setDoubleValue("steering-norm", net->gear_steer[i] );
 459             node->setDoubleValue("compression-norm", net->gear_compression[i] );
 460         }
 461
 462         /* these are ignored for now  ... */
 463         /*
 464         if ( net->cur_time ) {
 465             fgSetLong("/sim/time/cur-time-override", net->cur_time);
 466         }
 467
 468         globals->set_warp( net->warp );
 469         last_warp = net->warp;
 470         */
 471
 472         SGPropertyNode *node = fgGetNode("/surface-positions", true);
 473         node->setDoubleValue("elevator-pos-norm", net->elevator);
 474         node->setDoubleValue("elevator-trim-tab-pos-norm",
 475                              net->elevator_trim_tab);
 476         // FIXME: CLO 10/28/04 - This really should be separated out
 477         // into 2 values
 478         node->setDoubleValue("flap-pos-norm", net->left_flap);
 479         node->setDoubleValue("flap-pos-norm", net->right_flap);
 480         node->setDoubleValue("left-aileron-pos-norm", net->left_aileron);
 481         node->setDoubleValue("right-aileron-pos-norm", net->right_aileron);
 482         node->setDoubleValue("rudder-pos-norm", net->rudder);
 483         node->setDoubleValue("nose-wheel-pos-norm", net->nose_wheel);
 484         node->setDoubleValue("speedbrake-pos-norm", net->speedbrake);
 485         node->setDoubleValue("spoilers-pos-norm", net->spoilers);
 486     } else {
 487         SG_LOG( SG_IO, SG_ALERT,
 488                 "Error: version mismatch in FGNetFDM2Props()" );
 489         SG_LOG( SG_IO, SG_ALERT,
 490                 "\tread " << net->version << " need " << FG_NET_FDM_VERSION );
 491         SG_LOG( SG_IO, SG_ALERT,
 492                 "\tNeeds to upgrade net_fdm.hxx and recompile." );
 493     }
 494 }
 495
 496
 497 // process work for this port
 498 bool FGNativeFDM::process() {
 499     SGIOChannel *io = get_io_channel();
 500     int length = sizeof(buf);
 501
 502     if ( get_direction() == SG_IO_OUT ) {
 503         // cout << "size of cur_fdm_state = " << length << endl;
 504         FGProps2NetFDM( &buf );
 505         if ( ! io->write( (char *)(& buf), length ) ) {
 506             SG_LOG( SG_IO, SG_ALERT, "Error writing data." );
 507             return false;
 508         }
 509     } else if ( get_direction() == SG_IO_IN ) {
 510         if ( io->get_type() == sgFileType ) {
 511             if ( io->read( (char *)(& buf), length ) == length ) {
 512                 SG_LOG( SG_IO, SG_DEBUG, "Success reading data." );
 513                 FGNetFDM2Props( &buf );
 514             }
 515         } else {
 516             int result;
 517             result = io->read( (char *)(& buf), length );
 518             while ( result == length ) {
 519                 if ( result == length ) {
 520                     SG_LOG( SG_IO, SG_DEBUG, "  Success reading data." );
 521                     FGNetFDM2Props( &buf );
 522                 }
 523                 result = io->read( (char *)(& buf), length );
 524             }
 525         }
 526     }
 527
 528     return true;
 529 }
 530
 531
 532 // close the channel
 533 bool FGNativeFDM::close() {
 534     SGIOChannel *io = get_io_channel();
 535
 536     set_enabled( false );
 537
 538     if ( ! io->close() ) {
 539         return false;
 540     }
 541
 542     return true;
 543 }