65f6e343ab
The files in the attached tarball make the following changes to FlightGear: - rename the existing FGInterface::init() method to FGInterface::_setup to get it out of the way - move *all* FDM initialization code out of src/Main/fg_init.cxx and into FGInterface::init(), and clean up fg_init.cxx a little (especially by removing the zillions of attempts to place the plane on the ground at various locations in the code) - modify FGInterface::bind() so that no values are picked up automatically at bind time (they are set previously by init() instead) - modify the init() methods of the classes derived from FGInterface (i.e. larcsim, jsbsim, balloon, magic, and ada) to invoke FGInterface::init() explicitly before doing their own setup I don't claim that the code in FGInterface::init() is optimal (or even correct), but it seems to work for on-ground starts with both LaRCSim and JSBSim on runways pointing various directions from near sea level to about 700' ASL (the range I happened to test). I expect that Jon and Tony will want to look at the code and refactor and correct it now that they can see what's going on in one place. Here's a quick outline of what is invoked: cur_fdm_state = new <whatever>(dt); cur_fdm_state->init(); cur_fdm_state->bind(); The constructor allocates memory and sets default values only (with the help of the FGInterface::_setup() method). The init() method pull any required properties out of the property tree and sets up the initial state of the FDM. The bind() method takes ownership of FDM-related properties so that the FDM can publish them to the rest of the sim. Note that bind() and init() are virtual, so any implementation in a subclass will hide the implementation in FGInterface; that's why subclass implementations of init() and bind() have to invoke FGInterface::init() and FGInterface::bind() explicitly, probably at the start, so that they get the basic initialization.
109 lines
3.4 KiB
C++
109 lines
3.4 KiB
C++
// MagicCarpet.cxx -- interface to the "Magic Carpet" flight model
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//
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// Written by Curtis Olson, started October 1999.
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//
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// Copyright (C) 1999 Curtis L. Olson - curt@flightgear.org
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//
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// This program is free software; you can redistribute it and/or
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// modify it under the terms of the GNU General Public License as
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// published by the Free Software Foundation; either version 2 of the
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// License, or (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful, but
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// WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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// General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program; if not, write to the Free Software
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// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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//
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// $Id$
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#include <simgear/math/sg_geodesy.hxx>
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#include <simgear/math/point3d.hxx>
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#include <simgear/math/polar3d.hxx>
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#include <Controls/controls.hxx>
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#include <Main/globals.hxx>
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#include <Main/fg_props.hxx>
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#include "MagicCarpet.hxx"
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FGMagicCarpet::FGMagicCarpet( double dt ) {
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set_delta_t( dt );
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}
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FGMagicCarpet::~FGMagicCarpet() {
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}
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// Initialize the Magic Carpet flight model, dt is the time increment
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// for each subsequent iteration through the EOM
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void FGMagicCarpet::init() {
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// explicitly call the superclass's
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// init method first
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FGInterface::init();
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}
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// Run an iteration of the EOM (equations of motion)
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bool FGMagicCarpet::update( int multiloop ) {
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// cout << "FGLaRCsim::update()" << endl;
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double time_step = get_delta_t() * multiloop;
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// speed and distance traveled
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double speed = controls.get_throttle( 0 ) * 2000; // meters/sec
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double dist = speed * time_step;
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double kts = speed * SG_METER_TO_NM * 3600.0;
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_set_V_equiv_kts( kts );
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_set_V_calibrated_kts( kts );
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_set_V_ground_speed( kts );
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// angle of turn
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double turn_rate = controls.get_aileron() * SGD_PI_4; // radians/sec
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double turn = turn_rate * time_step;
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// update euler angles
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_set_Euler_Angles( get_Phi(), get_Theta(),
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fmod(get_Psi() + turn, SGD_2PI) );
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_set_Euler_Rates(0,0,0);
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// update (lon/lat) position
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double lat2, lon2, az2;
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if ( speed > SG_EPSILON ) {
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geo_direct_wgs_84 ( get_Altitude(),
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get_Latitude() * SGD_RADIANS_TO_DEGREES,
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get_Longitude() * SGD_RADIANS_TO_DEGREES,
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get_Psi() * SGD_RADIANS_TO_DEGREES,
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dist, &lat2, &lon2, &az2 );
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_set_Longitude( lon2 * SGD_DEGREES_TO_RADIANS );
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_set_Latitude( lat2 * SGD_DEGREES_TO_RADIANS );
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}
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// cout << "lon error = " << fabs(end.x()*SGD_RADIANS_TO_DEGREES - lon2)
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// << " lat error = " << fabs(end.y()*SGD_RADIANS_TO_DEGREES - lat2)
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// << endl;
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double sl_radius, lat_geoc;
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sgGeodToGeoc( get_Latitude(), get_Altitude(), &sl_radius, &lat_geoc );
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// update altitude
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double real_climb_rate = -controls.get_elevator() * 5000; // feet/sec
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_set_Climb_Rate( real_climb_rate / 500.0 );
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double climb = real_climb_rate * time_step;
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_set_Geocentric_Position( lat_geoc, get_Longitude(),
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sl_radius + get_Altitude() + climb );
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// cout << "sea level radius (ft) = " << sl_radius << endl;
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// cout << "(setto) sea level radius (ft) = " << get_Sea_level_radius() << endl;
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_set_Sea_level_radius( sl_radius * SG_METER_TO_FEET);
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_set_Altitude( get_Altitude() + climb );
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return true;
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}
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