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flightgear/src/Network/native_fdm.cxx
david d0eaafb1e1 Patches from Tony Peden to separate property XML I/O operations into a
separate header file.  This change will help integrate properties into
JSBSim.

Also, I (David Megginson) removed most of the SimGear include
statements from globals.hxx, reducing the amount of recompilation
every time SimGear changes.  This required making minor changes to a
lot of files that were depending on the side-effects of the inclusions
in globals.hxx.
2002-03-16 00:18:38 +00:00

234 lines
6.8 KiB
C++

// native_fdm.cxx -- FGFS "Native" flight dynamics protocal class
//
// Written by Curtis Olson, started September 2001.
//
// Copyright (C) 2001 Curtis L. Olson - curt@flightgear.org
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 2 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
//
// $Id$
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <simgear/debug/logstream.hxx>
#include <simgear/io/lowlevel.hxx> // endian tests
#include <simgear/io/iochannel.hxx>
#include <simgear/timing/sg_time.hxx>
#include <FDM/flight.hxx>
#include <Time/tmp.hxx>
#include <Main/fg_props.hxx>
#include <Main/globals.hxx>
#include "native_fdm.hxx"
// FreeBSD works better with this included last ... (?)
#if defined(WIN32) && !defined(__CYGWIN__)
# include <windows.h>
#else
# include <netinet/in.h> // htonl() ntohl()
#endif
// The function htond is defined this way due to the way some
// processors and OSes treat floating point values. Some will raise
// an exception whenever a "bad" floating point value is loaded into a
// floating point register. Solaris is notorious for this, but then
// so is LynxOS on the PowerPC. By translating the data in place,
// there is no need to load a FP register with the "corruped" floating
// point value. By doing the BIG_ENDIAN test, I can optimize the
// routine for big-endian processors so it can be as efficient as
// possible
static void htond (double &x)
{
if ( sgIsLittleEndian() ) {
int *Double_Overlay;
int Holding_Buffer;
Double_Overlay = (int *) &x;
Holding_Buffer = Double_Overlay [0];
Double_Overlay [0] = htonl (Double_Overlay [1]);
Double_Overlay [1] = htonl (Holding_Buffer);
} else {
return;
}
}
FGNativeFDM::FGNativeFDM() {
}
FGNativeFDM::~FGNativeFDM() {
}
// open hailing frequencies
bool FGNativeFDM::open() {
if ( is_enabled() ) {
SG_LOG( SG_IO, SG_ALERT, "This shouldn't happen, but the channel "
<< "is already in use, ignoring" );
return false;
}
SGIOChannel *io = get_io_channel();
if ( ! io->open( get_direction() ) ) {
SG_LOG( SG_IO, SG_ALERT, "Error opening channel communication layer." );
return false;
}
set_enabled( true );
cur_fdm_state->_set_Sea_level_radius( SG_EQUATORIAL_RADIUS_FT );
return true;
}
static void global2net( const FGInterface *global, FGNetFDM *net ) {
static const SGPropertyNode *visibility
= fgGetNode("/environment/visibility-m");
net->version = FG_NET_FDM_VERSION;
// positions
net->longitude = cur_fdm_state->get_Longitude();
net->latitude = cur_fdm_state->get_Latitude();
net->altitude = cur_fdm_state->get_Altitude() * SG_FEET_TO_METER;
net->phi = cur_fdm_state->get_Phi();
net->theta = cur_fdm_state->get_Theta();
net->psi = cur_fdm_state->get_Psi();
// velocities
net->vcas = cur_fdm_state->get_V_calibrated_kts();
net->climb_rate = cur_fdm_state->get_Climb_Rate();
// environment
net->cur_time = globals->get_time_params()->get_cur_time();
net->warp = globals->get_warp();
net->visibility = visibility->getDoubleValue();
// Convert the net buffer to network format
net->version = htonl(net->version);
htond(net->longitude);
htond(net->latitude);
htond(net->altitude);
htond(net->phi);
htond(net->theta);
htond(net->psi);
htond(net->vcas);
htond(net->climb_rate);
net->cur_time = htonl( net->cur_time );
net->warp = htonl( net->warp );
htond(net->visibility);
}
static void net2global( FGNetFDM *net, FGInterface *global ) {
static long int last_warp = 0;
// Convert to the net buffer from network format
net->version = ntohl(net->version);
htond(net->longitude);
htond(net->latitude);
htond(net->altitude);
htond(net->phi);
htond(net->theta);
htond(net->psi);
htond(net->vcas);
htond(net->climb_rate);
net->cur_time = ntohl(net->cur_time);
net->warp = ntohl(net->warp);
htond(net->visibility);
if ( net->version == FG_NET_FDM_VERSION ) {
// cout << "pos = " << net->longitude << " " << net->latitude << endl;
// cout << "sea level rad = " << cur_fdm_state->get_Sea_level_radius() << endl;
cur_fdm_state->_updateGeodeticPosition( net->latitude,
net->longitude,
net->altitude
* SG_METER_TO_FEET );
cur_fdm_state->_set_Euler_Angles( net->phi,
net->theta,
net->psi );
cur_fdm_state->_set_V_calibrated_kts( net->vcas );
cur_fdm_state->_set_Climb_Rate( net->climb_rate );
if ( net->cur_time ) {
fgSetLong("/sim/time/cur-time-override", net->cur_time);
}
globals->set_warp( net->warp );
if ( net->warp != last_warp ) {
fgUpdateSkyAndLightingParams();
}
last_warp = net->warp;
fgSetDouble( "/environment/visibility-m", net->visibility );
} else {
SG_LOG( SG_IO, SG_ALERT, "Error: version mismatch in net2global()" );
SG_LOG( SG_IO, SG_ALERT,
"\tread " << net->version << " need " << FG_NET_FDM_VERSION );
SG_LOG( SG_IO, SG_ALERT,
"\tsomeone needs to upgrade net_fdm.hxx and recompile." );
}
}
// process work for this port
bool FGNativeFDM::process() {
SGIOChannel *io = get_io_channel();
int length = sizeof(buf);
if ( get_direction() == SG_IO_OUT ) {
// cout << "size of cur_fdm_state = " << length << endl;
global2net( cur_fdm_state, &buf );
if ( ! io->write( (char *)(& buf), length ) ) {
SG_LOG( SG_IO, SG_ALERT, "Error writing data." );
return false;
}
} else if ( get_direction() == SG_IO_IN ) {
if ( io->get_type() == sgFileType ) {
if ( io->read( (char *)(& buf), length ) == length ) {
SG_LOG( SG_IO, SG_DEBUG, "Success reading data." );
net2global( &buf, cur_fdm_state );
}
} else {
while ( io->read( (char *)(& buf), length ) == length ) {
SG_LOG( SG_IO, SG_DEBUG, "Success reading data." );
net2global( &buf, cur_fdm_state );
}
}
}
return true;
}
// close the channel
bool FGNativeFDM::close() {
SGIOChannel *io = get_io_channel();
set_enabled( false );
if ( ! io->close() ) {
return false;
}
return true;
}