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