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flightgear/src/FDM/ExternalPipe/ExternalPipe.cxx
curt 86249209b9 This is a work in progress. I am extending the "ExternalPipe" protocol to
have a "property" mode as well as the original "binary" mode.  The property mode
will allow the remote module to request any set of properties, and it will send
those properties each frame.  The remote module can reply with a list of arbitrary
property name/value pairs to update on the FlightGear side.

This is a first stab, so it's not the cleanest, most well concieved code, but it
allows an external module (communicating via a pipe) to have a huge amount of
flexibility in the data in can access and update.
2005-04-19 01:44:56 +00:00

566 lines
17 KiB
C++

// ExternalPipe.cxx -- a "pipe" interface to an external flight dynamics model
//
// Written by Curtis Olson, started March 2003.
//
// Copyright (C) 2003 Curtis L. Olson - http://www.flightgear.org/~curt
//
// 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
#ifdef HAVE_MKFIFO
# include <sys/types.h> // mkfifo() umask()
# include <sys/stat.h> // mkfifo() umask()
# include <errno.h> // perror()
# include <unistd.h> // unlink()
#endif
#include <stdio.h> // FILE*, fopen(), fread(), fwrite(), et. al.
#include <simgear/debug/logstream.hxx>
#include <simgear/io/lowlevel.hxx> // endian tests
#include <simgear/misc/strutils.hxx> // split()
#include <Main/fg_props.hxx>
#include <Network/native_ctrls.hxx>
#include <Network/native_fdm.hxx>
#include <Scenery/scenery.hxx>
#include "ExternalPipe.hxx"
static const int MAX_BUF = 32768;
FGExternalPipe::FGExternalPipe( double dt, string name, string protocol ) {
valid = true;
last_weight = 0.0;
last_cg_offset = -9999.9;
buf = new char[MAX_BUF];
// clear property request list
property_names.clear();
nodes.clear();
#ifdef HAVE_MKFIFO
fifo_name_1 = name + "1";
fifo_name_2 = name + "2";
SG_LOG( SG_IO, SG_ALERT, "ExternalPipe Inited with " << name );
// Make the named pipe
umask(0);
int result;
result = mkfifo( fifo_name_1.c_str(), 0644 );
if ( result == -1 ) {
SG_LOG( SG_IO, SG_ALERT, "Unable to create named pipe: "
<< fifo_name_1 );
perror( "ExternalPipe()" );
}
result = mkfifo( fifo_name_2.c_str(), 0644 );
if ( result == -1 ) {
SG_LOG( SG_IO, SG_ALERT, "Unable to create named pipe: "
<< fifo_name_2 );
perror( "ExternalPipe()" );
}
pd1 = fopen( fifo_name_1.c_str(), "w" );
if ( pd1 == NULL ) {
SG_LOG( SG_IO, SG_ALERT, "Unable to open named pipe: " << fifo_name_1 );
valid = false;
}
pd2 = fopen( fifo_name_2.c_str(), "r" );
if ( pd2 == NULL ) {
SG_LOG( SG_IO, SG_ALERT, "Unable to open named pipe: " << fifo_name_2 );
valid = false;
}
#endif
_protocol = protocol;
if ( _protocol != "binary" && _protocol != "property" ) {
SG_LOG( SG_IO, SG_ALERT, "Constructor(): Unknown ExternalPipe protocol."
<< " Must be 'binary' or 'property'."
<< " (assuming binary)" );
_protocol = "binary";
}
}
FGExternalPipe::~FGExternalPipe() {
delete [] buf;
SG_LOG( SG_IO, SG_INFO, "Closing up the ExternalPipe." );
#ifdef HAVE_MKFIFO
// close
int result;
result = fclose( pd1 );
if ( result ) {
SG_LOG( SG_IO, SG_ALERT, "Unable to close named pipe: "
<< fifo_name_1 );
perror( "~FGExternalPipe()" );
}
result = fclose( pd2 );
if ( result ) {
SG_LOG( SG_IO, SG_ALERT, "Unable to close named pipe: "
<< fifo_name_2 );
perror( "~FGExternalPipe()" );
}
#endif
}
static int write_binary( char cmd_type, FILE *pd, char *cmd, int len ) {
#ifdef HAVE_MKFIFO
char *buf = new char[len + 3];
// write 2 byte command length + command type + command
unsigned char hi = (len + 1) / 256;
unsigned char lo = (len + 1) - (hi * 256);
// cout << "len = " << len << " hi = " << (int)hi << " lo = "
// << (int)lo << endl;
buf[0] = hi;
buf[1] = lo;
buf[2] = cmd_type;
memcpy( buf + 3, cmd, len );
if ( cmd_type == '1' ) {
cout << "writing '";
for ( int i = 0; i < len + 3; ++i ) {
cout << buf[i];
}
cout << "' (" << cmd << ")" << endl;
} else if ( cmd_type == '2' ) {
cout << "writing controls packet" << endl;
} else {
cout << "writing unknown command?" << endl;
}
// for ( int i = 0; i < len + 3; ++i ) {
// cout << " " << (int)buf[i];
// }
// cout << endl;
int result = fwrite( buf, len + 3, 1, pd );
if ( result != 1 ) {
perror( "write_binary()" );
SG_LOG( SG_IO, SG_ALERT, "Write error to named pipe: " << pd );
}
// cout << "wrote " << len + 3 << " bytes." << endl;
delete [] buf;
return result;
#else
return 0;
#endif
}
static int write_property( FILE *pd, char *cmd ) {
int len = strlen(cmd);
#ifdef HAVE_MKFIFO
char *buf = new char[len + 1];
memcpy( buf, cmd, len );
buf[len] = '\n';
int result = fwrite( buf, len + 1, 1, pd );
if ( result == len + 1 ) {
perror( "write_property()" );
SG_LOG( SG_IO, SG_ALERT, "Write error to named pipe: " << pd );
}
// cout << "wrote " << len + 1 << " bytes." << endl;
delete [] buf;
return result;
#else
return 0;
#endif
}
// Wrapper for the ExternalPipe flight model initialization. dt is
// the time increment for each subsequent iteration through the EOM
void FGExternalPipe::init() {
// Explicitly call the superclass's
// init method first.
common_init();
if ( _protocol == "binary" ) {
init_binary();
} else if ( _protocol == "property" ) {
init_property();
} else {
SG_LOG( SG_IO, SG_ALERT, "Init(): Unknown ExternalPipe protocol."
<< " Must be 'binary' or 'property'."
<< " (assuming binary)" );
}
}
// Initialize the ExternalPipe flight model using the binary protocol,
// dt is the time increment for each subsequent iteration through the
// EOM
void FGExternalPipe::init_binary() {
cout << "init_binary()" << endl;
double lon = fgGetDouble( "/sim/presets/longitude-deg" );
double lat = fgGetDouble( "/sim/presets/latitude-deg" );
double alt = fgGetDouble( "/sim/presets/altitude-ft" );
double ground = fgGetDouble( "/environment/ground-elevation-m" );
double heading = fgGetDouble("/sim/presets/heading-deg");
double speed = fgGetDouble( "/sim/presets/airspeed-kt" );
double weight = fgGetDouble( "/sim/aircraft-weight-lbs" );
double cg_offset = fgGetDouble( "/sim/aircraft-cg-offset-inches" );
char cmd[256];
int result;
sprintf( cmd, "longitude-deg=%.8f", lon );
result = write_binary( '1', pd1, cmd, strlen(cmd) );
sprintf( cmd, "latitude-deg=%.8f", lat );
result = write_binary( '1', pd1, cmd, strlen(cmd) );
sprintf( cmd, "altitude-ft=%.8f", alt );
result = write_binary( '1', pd1, cmd, strlen(cmd) );
sprintf( cmd, "ground-m=%.8f", ground );
result = write_binary( '1', pd1, cmd, strlen(cmd) );
sprintf( cmd, "speed-kts=%.8f", speed );
result = write_binary( '1', pd1, cmd, strlen(cmd) );
sprintf( cmd, "heading-deg=%.8f", heading );
result = write_binary( '1', pd1, cmd, strlen(cmd) );
if ( weight > 1000.0 ) {
sprintf( cmd, "aircraft-weight-lbs=%.2f", weight );
result = write_binary( '1', pd1, cmd, strlen(cmd) );
}
last_weight = weight;
if ( cg_offset > -5.0 || cg_offset < 5.0 ) {
sprintf( cmd, "aircraft-cg-offset-inches=%.2f", cg_offset );
result = write_binary( '1', pd1, cmd, strlen(cmd) );
}
last_cg_offset = cg_offset;
SG_LOG( SG_IO, SG_ALERT, "before sending reset command." );
if( fgGetBool("/sim/presets/onground") ) {
sprintf( cmd, "reset=ground" );
} else {
sprintf( cmd, "reset=air" );
}
result = write_binary( '1', pd1, cmd, strlen(cmd) );
fflush( pd1 );
SG_LOG( SG_IO, SG_ALERT, "Remote FDM init() finished." );
}
// Initialize the ExternalPipe flight model using the property
// protocol, dt is the time increment for each subsequent iteration
// through the EOM
void FGExternalPipe::init_property() {
cout << "init_property()" << endl;
double lon = fgGetDouble( "/sim/presets/longitude-deg" );
double lat = fgGetDouble( "/sim/presets/latitude-deg" );
double alt = fgGetDouble( "/sim/presets/altitude-ft" );
double ground = fgGetDouble( "/environment/ground-elevation-m" );
double heading = fgGetDouble("/sim/presets/heading-deg");
double speed = fgGetDouble( "/sim/presets/airspeed-kt" );
double weight = fgGetDouble( "/sim/aircraft-weight-lbs" );
double cg_offset = fgGetDouble( "/sim/aircraft-cg-offset-inches" );
char cmd[256];
int result;
sprintf( cmd, "init longitude-deg=%.8f", lon );
result = write_property( pd1, cmd );
sprintf( cmd, "init latitude-deg=%.8f", lat );
result = write_property( pd1, cmd );
sprintf( cmd, "init altitude-ft=%.8f", alt );
result = write_property( pd1, cmd );
sprintf( cmd, "init ground-m=%.8f", ground );
result = write_property( pd1, cmd );
sprintf( cmd, "init speed-kts=%.8f", speed );
result = write_property( pd1, cmd );
sprintf( cmd, "init heading-deg=%.8f", heading );
result = write_property( pd1, cmd );
if ( weight > 1000.0 ) {
sprintf( cmd, "init aircraft-weight-lbs=%.2f", weight );
result = write_property( pd1, cmd );
}
last_weight = weight;
if ( cg_offset > -5.0 || cg_offset < 5.0 ) {
sprintf( cmd, "init aircraft-cg-offset-inches=%.2f", cg_offset );
result = write_property( pd1, cmd );
}
last_cg_offset = cg_offset;
SG_LOG( SG_IO, SG_ALERT, "before sending reset command." );
if( fgGetBool("/sim/presets/onground") ) {
sprintf( cmd, "reset ground" );
} else {
sprintf( cmd, "reset air" );
}
result = write_property( pd1, cmd );
fflush( pd1 );
SG_LOG( SG_IO, SG_ALERT, "Remote FDM init() finished." );
}
// Wrapper for the ExternalPipe update routines. dt is the time
// increment for each subsequent iteration through the EOM
void FGExternalPipe::update( double dt ) {
if ( _protocol == "binary" ) {
update_binary(dt);
} else if ( _protocol == "property" ) {
update_property(dt);
} else {
SG_LOG( SG_IO, SG_ALERT, "Init(): Unknown ExternalPipe protocol."
<< " Must be 'binary' or 'property'."
<< " (assuming binary)" );
}
}
// Run an iteration of the EOM.
void FGExternalPipe::update_binary( double dt ) {
#ifdef HAVE_MKFIFO
SG_LOG( SG_IO, SG_INFO, "Start FGExternalPipe::udpate_binary()" );
int length;
int result;
if ( is_suspended() ) {
return;
}
int iterations = _calc_multiloop(dt);
double weight = fgGetDouble( "/sim/aircraft-weight-lbs" );
static double last_weight = 0.0;
if ( fabs( weight - last_weight ) > 0.01 ) {
char cmd[256];
sprintf( cmd, "aircraft-weight-lbs=%.2f", weight );
result = write_binary( '1', pd1, cmd, strlen(cmd) );
}
last_weight = weight;
double cg_offset = fgGetDouble( "/sim/aircraft-cg-offset-inches" );
if ( fabs( cg_offset - last_cg_offset ) > 0.01 ) {
char cmd[256];
sprintf( cmd, "aircraft-cg-offset-inches=%.2f", cg_offset );
result = write_binary( '1', pd1, cmd, strlen(cmd) );
}
last_cg_offset = cg_offset;
// Send control positions to remote fdm
length = sizeof(ctrls);
FGProps2NetCtrls( &ctrls, true, false );
char *ptr = buf;
*((int *)ptr) = iterations;
// cout << "iterations = " << iterations << endl;
ptr += sizeof(int);
memcpy( ptr, (char *)(&ctrls), length );
cout << "writing control structure, size = "
<< length + sizeof(int) << endl;
result = write_binary( '2', pd1, buf, length + sizeof(int) );
fflush( pd1 );
// Read fdm values
length = sizeof(fdm);
cout << "about to read fdm data from remote fdm." << endl;
result = fread( (char *)(& fdm), length, 1, pd2 );
if ( result != length ) {
SG_LOG( SG_IO, SG_ALERT, "Read error from named pipe: "
<< fifo_name_2 );
} else {
cout << " read successful." << endl;
}
FGNetFDM2Props( &fdm, false );
#endif
}
// Process remote FDM "set" commands
static void process_set_command( const string_list &tokens ) {
if ( tokens[1] == "geodetic_position" ) {
double lat_rad = atof( tokens[2].c_str() );
double lon_rad = atof( tokens[3].c_str() );
double alt_m = atof( tokens[4].c_str() );
cur_fdm_state->_updateGeodeticPosition( lat_rad, lon_rad,
alt_m * SG_METER_TO_FEET );
double agl_m = alt_m - globals->get_scenery()->get_cur_elev();
cur_fdm_state->_set_Altitude_AGL( agl_m * SG_METER_TO_FEET );
} else if ( tokens[1] == "euler_angles" ) {
double phi_rad = atof( tokens[2].c_str() );
double theta_rad = atof( tokens[3].c_str() );
double psi_rad = atof( tokens[4].c_str() );
cur_fdm_state->_set_Euler_Angles( phi_rad, theta_rad, psi_rad );
} else if ( tokens[1] == "euler_rates" ) {
double phidot = atof( tokens[2].c_str() );
double thetadot = atof( tokens[3].c_str() );
double psidot = atof( tokens[4].c_str() );
cur_fdm_state->_set_Euler_Rates( phidot, thetadot, psidot );
} else if ( tokens[1] == "alpha" ) {
cur_fdm_state->_set_Alpha( atof(tokens[2].c_str()) );
} else if ( tokens[1] == "beta" ) {
cur_fdm_state->_set_Beta( atof(tokens[2].c_str()) );
#if 0
cur_fdm_state->_set_V_calibrated_kts( net->vcas );
cur_fdm_state->_set_Climb_Rate( net->climb_rate );
cur_fdm_state->_set_Velocities_Local( net->v_north,
net->v_east,
net->v_down );
cur_fdm_state->_set_Velocities_Wind_Body( net->v_wind_body_north,
net->v_wind_body_east,
net->v_wind_body_down );
cur_fdm_state->_set_Accels_Pilot_Body( net->A_X_pilot,
net->A_Y_pilot,
net->A_Z_pilot );
#endif
} else {
fgSetString( tokens[1].c_str(), tokens[2].c_str() );
}
}
// Run an iteration of the EOM.
void FGExternalPipe::update_property( double dt ) {
// cout << "update_property()" << endl;
#ifdef HAVE_MKFIFO
// SG_LOG( SG_IO, SG_INFO, "Start FGExternalPipe::udpate()" );
int result;
char cmd[256];
if ( is_suspended() ) {
return;
}
int iterations = _calc_multiloop(dt);
double weight = fgGetDouble( "/sim/aircraft-weight-lbs" );
static double last_weight = 0.0;
if ( fabs( weight - last_weight ) > 0.01 ) {
sprintf( cmd, "init aircraft-weight-lbs=%.2f", weight );
result = write_property( pd1, cmd );
}
last_weight = weight;
double cg_offset = fgGetDouble( "/sim/aircraft-cg-offset-inches" );
if ( fabs( cg_offset - last_cg_offset ) > 0.01 ) {
sprintf( cmd, "init aircraft-cg-offset-inches=%.2f", cg_offset );
result = write_property( pd1, cmd );
}
last_cg_offset = cg_offset;
// Send requested property values to fdm
for ( unsigned int i = 0; i < nodes.size(); i++ ) {
sprintf( cmd, "set %s %s", property_names[i].c_str(),
nodes[i]->getStringValue() );
// cout << " sending " << cmd << endl;
result = write_property( pd1, cmd );
}
sprintf( cmd, "update %d", iterations );
write_property( pd1, cmd );
fflush( pd1 );
// Read FDM response
// cout << "ready to read fdm response" << endl;
bool done = false;
while ( !done ) {
if ( fgets( cmd, 256, pd2 ) == NULL ) {
cout << "Error reading data" << endl;
} else {
// cout << " read " << strlen(cmd) << " bytes" << endl;
}
// chop trailing newline
cmd[strlen(cmd)-1] = '\0';
// cout << cmd << endl;
string_list tokens = simgear::strutils::split( cmd, " " );
if ( tokens[0] == "request" ) {
// save the long form name
property_names.push_back( tokens[1] );
// now do the property name lookup and cache the pointer
SGPropertyNode *node = fgGetNode( tokens[1].c_str() );
if ( node == NULL ) {
// node doesn't exist so create with requested type
node = fgGetNode( tokens[1].c_str(), true );
if ( tokens[2] == "bool" ) {
node->setBoolValue(true);
} else if ( tokens[2] == "int" ) {
node->setIntValue(0);
} else if ( tokens[2] == "double" ) {
node->setDoubleValue(0.0);
} else if ( tokens[2] == "string" ) {
node->setStringValue("");
} else {
cout << "Unknown data type: " << tokens[2]
<< " for " << tokens[1] << endl;
}
}
nodes.push_back( node );
} else if ( tokens[0] == "set" ) {
process_set_command( tokens );
} else if ( tokens[0] == "update" ) {
done = true;
} else {
cout << "unknown command = " << cmd << endl;
}
}
#endif
}