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
  74 FGNativeFDM::FGNativeFDM() {
  75 }
  76
  77 FGNativeFDM::~FGNativeFDM() {
  78 }
  79
  80
  81 // open hailing frequencies
  82 bool FGNativeFDM::open() {
  83     if ( is_enabled() ) {
  84         SG_LOG( SG_IO, SG_ALERT, "This shouldn't happen, but the channel "
  85                 << "is already in use, ignoring" );
  86         return false;
  87     }
  88
  89     SGIOChannel *io = get_io_channel();
  90
  91     if ( ! io->open( get_direction() ) ) {
  92         SG_LOG( SG_IO, SG_ALERT, "Error opening channel communication layer." );
  93         return false;
  94     }
  95
  96     set_enabled( true );
  97
  98     // initialize time stamp to something reasonably current
  99     last_time.stamp();
 100
 101     // Is this really needed here ????
 102     cur_fdm_state->_set_Sea_level_radius( SG_EQUATORIAL_RADIUS_FT );
 103
 104     return true;
 105 }
 106
 107
 108 void FGProps2NetFDM( FGNetFDM *net, bool net_byte_order ) {
 109     int i;
 110
 111     // Version sanity checking
 112     net->version = FG_NET_FDM_VERSION;
 113
 114     // Aero parameters
 115     net->longitude = cur_fdm_state->get_Longitude();
 116     net->latitude = cur_fdm_state->get_Latitude();
 117     net->altitude = cur_fdm_state->get_Altitude() * SG_FEET_TO_METER;
 118     net->phi = cur_fdm_state->get_Phi();
 119     net->theta = cur_fdm_state->get_Theta();
 120     net->psi = cur_fdm_state->get_Psi();
 121     net->phidot = cur_fdm_state->get_Phi_dot_degps() * SG_DEGREES_TO_RADIANS;
 122     net->thetadot = cur_fdm_state->get_Theta_dot_degps()
 123         * SG_DEGREES_TO_RADIANS;
 124     net->psidot = cur_fdm_state->get_Psi_dot_degps() * SG_DEGREES_TO_RADIANS;
 125
 126     net->vcas = cur_fdm_state->get_V_calibrated_kts();
 127     net->climb_rate = cur_fdm_state->get_Climb_Rate();
 128
 129     net->v_north = cur_fdm_state->get_V_north();
 130     net->v_east = cur_fdm_state->get_V_east();
 131     net->v_down = cur_fdm_state->get_V_down();
 132     net->v_wind_body_north = cur_fdm_state->get_uBody();
 133     net->v_wind_body_east = cur_fdm_state->get_vBody();
 134     net->v_wind_body_down = cur_fdm_state->get_wBody();
 135     net->stall_warning = fgGetDouble("/sim/alarms/stall-warning", 0.0);
 136
 137     net->A_X_pilot = cur_fdm_state->get_A_X_pilot();
 138     net->A_Y_pilot = cur_fdm_state->get_A_Y_pilot();
 139     net->A_Z_pilot = cur_fdm_state->get_A_Z_pilot();
 140
 141     // Engine parameters
 142     net->num_engines = FGNetFDM::FG_MAX_ENGINES;
 143     for ( i = 0; i < net->num_engines; ++i ) {
 144         SGPropertyNode *node = fgGetNode("engines/engine", i, true);
 145         if ( node->getBoolValue( "running" ) ) {
 146             net->eng_state[0] = 2;
 147         } else if ( node->getBoolValue( "cranking" ) ) {
 148             net->eng_state[0] = 1;
 149         } else {
 150             net->eng_state[0] = 0;
 151         }
 152         net->rpm[i] = node->getDoubleValue( "rpm" );
 153         net->fuel_flow[i] = node->getDoubleValue( "fuel-flow-gph" );
 154         net->EGT[i] = node->getDoubleValue( "egt-degf" );
 155         // cout << "egt = " << aero->EGT << endl;
 156         net->oil_temp[i] = node->getDoubleValue( "oil-temperature-degf" );
 157         net->oil_px[i] = node->getDoubleValue( "oil-pressure-psi" );
 158     }
 159
 160     // Consumables
 161     net->num_tanks = FGNetFDM::FG_MAX_TANKS;
 162     for ( i = 0; i < net->num_tanks; ++i ) {
 163         SGPropertyNode *node = fgGetNode("/consumables/fuel/tank", i, true);
 164         net->fuel_quantity[i] = node->getDoubleValue("level-gal_us");
 165     }
 166
 167     // Gear and flaps
 168     net->num_wheels = FGNetFDM::FG_MAX_WHEELS;
 169     for (i = 0; i < net->num_wheels; ++i ) {
 170         SGPropertyNode *node = fgGetNode("/gear/gear", i, true);
 171         net->wow[i] = node->getDoubleValue("wow");
 172     }
 173
 174     // cout << "Flap deflection = " << aero->dflap << endl;
 175     net->flap_deflection = fgGetDouble("/surface-positions/flap-pos-norm" );
 176
 177     // the following really aren't used in this context
 178     net->cur_time = globals->get_time_params()->get_cur_time();
 179     net->warp = globals->get_warp();
 180     net->visibility = fgGetDouble("/environment/visibility-m");
 181
 182     if ( net_byte_order ) {
 183         // Convert the net buffer to network format
 184         net->version = htonl(net->version);
 185
 186         htond(net->longitude);
 187         htond(net->latitude);
 188         htond(net->altitude);
 189         htond(net->phi);
 190         htond(net->theta);
 191         htond(net->psi);
 192
 193         htond(net->phidot);
 194         htond(net->thetadot);
 195         htond(net->psidot);
 196         htond(net->vcas);
 197         htond(net->climb_rate);
 198         htond(net->v_north);
 199         htond(net->v_east);
 200         htond(net->v_down);
 201         htond(net->v_wind_body_north);
 202         htond(net->v_wind_body_east);
 203         htond(net->v_wind_body_down);
 204         htond(net->stall_warning);
 205
 206         htond(net->A_X_pilot);
 207         htond(net->A_Y_pilot);
 208         htond(net->A_Z_pilot);
 209
 210         for ( i = 0; i < net->num_engines; ++i ) {
 211             htonl(net->eng_state[i]);
 212             htond(net->rpm[i]);
 213             htond(net->fuel_flow[i]);
 214             htond(net->EGT[i]);
 215             htond(net->oil_temp[i]);
 216             htond(net->oil_px[i]);
 217         }
 218         net->num_engines = htonl(net->num_engines);
 219
 220         for ( i = 0; i < net->num_tanks; ++i ) {
 221             htond(net->fuel_quantity[i]);
 222         }
 223         net->num_tanks = htonl(net->num_tanks);
 224
 225         for ( i = 0; i < net->num_wheels; ++i ) {
 226             net->wow[i] = htonl(net->wow[i]);
 227         }
 228         net->num_wheels = htonl(net->num_wheels);
 229         htond(net->flap_deflection);
 230
 231         net->cur_time = htonl( net->cur_time );
 232         net->warp = htonl( net->warp );
 233         htond(net->visibility);
 234     }
 235 }
 236
 237
 238 void FGNetFDM2Props( FGNetFDM *net, bool net_byte_order ) {
 239     int i;
 240
 241     if ( net_byte_order ) {
 242         // Convert to the net buffer from network format
 243         net->version = ntohl(net->version);
 244
 245         htond(net->longitude);
 246         htond(net->latitude);
 247         htond(net->altitude);
 248         htond(net->phi);
 249         htond(net->theta);
 250         htond(net->psi);
 251
 252         htond(net->phidot);
 253         htond(net->thetadot);
 254         htond(net->psidot);
 255         htond(net->vcas);
 256         htond(net->climb_rate);
 257         htond(net->v_north);
 258         htond(net->v_east);
 259         htond(net->v_down);
 260         htond(net->v_wind_body_north);
 261         htond(net->v_wind_body_east);
 262         htond(net->v_wind_body_down);
 263         htond(net->stall_warning);
 264
 265         htond(net->A_X_pilot);
 266         htond(net->A_Y_pilot);
 267         htond(net->A_Z_pilot);
 268
 269         net->num_engines = htonl(net->num_engines);
 270         for ( i = 0; i < net->num_engines; ++i ) {
 271             htonl(net->eng_state[i]);
 272             htond(net->rpm[i]);
 273             htond(net->fuel_flow[i]);
 274             htond(net->EGT[i]);
 275             htond(net->oil_temp[i]);
 276             htond(net->oil_px[i]);
 277         }
 278
 279         net->num_tanks = htonl(net->num_tanks);
 280         for ( i = 0; i < net->num_tanks; ++i ) {
 281             htond(net->fuel_quantity[i]);
 282         }
 283
 284         net->num_wheels = htonl(net->num_wheels);
 285         // I don't need to convert the Wow flags, since they are one
 286         // byte in size
 287         htond(net->flap_deflection);
 288
 289         net->cur_time = ntohl(net->cur_time);
 290         net->warp = ntohl(net->warp);
 291         htond(net->visibility);
 292     }
 293
 294     if ( net->version == FG_NET_FDM_VERSION ) {
 295         // cout << "pos = " << net->longitude << " " << net->latitude << endl;
 296         // cout << "sea level rad = " << cur_fdm_state->get_Sea_level_radius()
 297         //      << endl;
 298         cur_fdm_state->_updateGeodeticPosition( net->latitude,
 299                                                 net->longitude,
 300                                                 net->altitude
 301                                                   * SG_METER_TO_FEET );
 302         cur_fdm_state->_set_Euler_Angles( net->phi,
 303                                           net->theta,
 304                                           net->psi );
 305         cur_fdm_state->_set_Euler_Rates( net->phidot,
 306                                          net->thetadot,
 307                                          net->psidot );
 308         cur_fdm_state->_set_V_calibrated_kts( net->vcas );
 309         cur_fdm_state->_set_Climb_Rate( net->climb_rate );
 310         cur_fdm_state->_set_Velocities_Local( net->v_north,
 311                                               net->v_east,
 312                                               net->v_down );
 313         cur_fdm_state->_set_Velocities_Wind_Body( net->v_wind_body_north,
 314                                                   net->v_wind_body_east,
 315                                                   net->v_wind_body_down );
 316
 317         fgSetDouble( "/sim/alarms/stall-warning", net->stall_warning );
 318         cur_fdm_state->_set_Accels_Pilot_Body( net->A_X_pilot,
 319                                                net->A_Y_pilot,
 320                                                net->A_Z_pilot );
 321
 322         for ( i = 0; i < net->num_engines; ++i ) {
 323             SGPropertyNode *node = fgGetNode( "engines/engine", i, true );
 324
 325             // node->setBoolValue("running", t->isRunning());
 326             // node->setBoolValue("cranking", t->isCranking());
 327
 328             // cout << net->eng_state[i] << endl;
 329             if ( net->eng_state[i] == 0 ) {
 330                 node->setBoolValue( "cranking", false );
 331                 node->setBoolValue( "running", false );
 332             } else if ( net->eng_state[i] == 1 ) {
 333                 node->setBoolValue( "cranking", true );
 334                 node->setBoolValue( "running", false );
 335             } else if ( net->eng_state[i] == 2 ) {
 336                 node->setBoolValue( "cranking", false );
 337                 node->setBoolValue( "running", true );
 338             }
 339
 340             node->setDoubleValue( "rpm", net->rpm[i] );
 341             node->setDoubleValue( "fuel-flow-gph", net->fuel_flow[i] );
 342             node->setDoubleValue( "egt-degf", net->EGT[i] );
 343             node->setDoubleValue( "oil-temperature-degf", net->oil_temp[i] );
 344             node->setDoubleValue( "oil-pressure-psi", net->oil_px[i] );
 345         }
 346
 347         for (i = 0; i < net->num_tanks; ++i ) {
 348             SGPropertyNode * node
 349                 = fgGetNode("/consumables/fuel/tank", i, true);
 350             node->setDoubleValue("level-gal_us", net->fuel_quantity[i] );
 351         }
 352
 353         for (i = 0; i < net->num_wheels; ++i ) {
 354             SGPropertyNode * node
 355                 = fgGetNode("/gear/gear", i, true);
 356             node->setDoubleValue("wow", net->wow[i] );
 357         }
 358
 359         fgSetDouble("/surface-positions/flap-pos-norm", net->flap_deflection);
 360         SGPropertyNode * node = fgGetNode("/controls", true);
 361         fgSetDouble("/surface-positions/elevator-pos-norm",
 362                     node->getDoubleValue( "elevator" ));
 363         fgSetDouble("/surface-positions/rudder-pos-norm",
 364                     node->getDoubleValue( "rudder" ));
 365         fgSetDouble("/surface-positions/left-aileron-pos-norm",
 366                     node->getDoubleValue( "aileron" ));
 367         fgSetDouble("/surface-positions/right-aileron-pos-norm",
 368                     -node->getDoubleValue( "aileron" ));
 369
 370         /* these are ignored for now  ... */
 371         /*
 372         if ( net->cur_time ) {
 373             fgSetLong("/sim/time/cur-time-override", net->cur_time);
 374         }
 375
 376         globals->set_warp( net->warp );
 377         last_warp = net->warp;
 378         */
 379     } else {
 380         SG_LOG( SG_IO, SG_ALERT,
 381                 "Error: version mismatch in FGNetFDM2Props()" );
 382         SG_LOG( SG_IO, SG_ALERT,
 383                 "\tread " << net->version << " need " << FG_NET_FDM_VERSION );
 384         SG_LOG( SG_IO, SG_ALERT,
 385                 "\tNeeds to upgrade net_fdm.hxx and recompile." );
 386     }
 387 }
 388
 389
 390 // process work for this port
 391 bool FGNativeFDM::process() {
 392     SGIOChannel *io = get_io_channel();
 393     int length = sizeof(buf);
 394
 395     if ( get_direction() == SG_IO_OUT ) {
 396         // cout << "size of cur_fdm_state = " << length << endl;
 397         FGProps2NetFDM( &buf );
 398         if ( ! io->write( (char *)(& buf), length ) ) {
 399             SG_LOG( SG_IO, SG_ALERT, "Error writing data." );
 400             return false;
 401         }
 402     } else if ( get_direction() == SG_IO_IN ) {
 403         if ( io->get_type() == sgFileType ) {
 404             if ( io->read( (char *)(& buf), length ) == length ) {
 405                 SG_LOG( SG_IO, SG_DEBUG, "Success reading data." );
 406                 FGNetFDM2Props( &buf );
 407             }
 408         } else {
 409             int result;
 410             result = io->read( (char *)(& buf), length );
 411             while ( result == length ) {
 412                 if ( result == length ) {
 413                     SG_LOG( SG_IO, SG_DEBUG, "  Success reading data." );
 414                     FGNetFDM2Props( &buf );
 415                 }
 416                 result = io->read( (char *)(& buf), length );
 417             }
 418         }
 419     }
 420
 421     return true;
 422 }
 423
 424
 425 // close the channel
 426 bool FGNativeFDM::close() {
 427     SGIOChannel *io = get_io_channel();
 428
 429     set_enabled( false );
 430
 431     if ( ! io->close() ) {
 432         return false;
 433     }
 434
 435     return true;
 436 }