1 /*****************************************************************************
3 Module: BalloonSimInterface.cxx
4 Author: Christian Mayer
8 -------- Copyright (C) 1999 Christian Mayer (fgfs@christianmayer.de) --------
10 This program is free software; you can redistribute it and/or modify it under
11 the terms of the GNU General Public License as published by the Free Software
12 Foundation; either version 2 of the License, or (at your option) any later
15 This program is distributed in the hope that it will be useful, but WITHOUT
16 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
17 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
20 You should have received a copy of the GNU General Public License along with
21 this program; if not, write to the Free Software Foundation, Inc., 59 Temple
22 Place - Suite 330, Boston, MA 02111-1307, USA.
24 Further information about the GNU General Public License can also be found on
25 the world wide web at http://www.gnu.org.
27 FUNCTIONAL DESCRIPTION
28 ------------------------------------------------------------------------------
29 Interface to the hot air balloon simulator
32 ------------------------------------------------------------------------------
33 01.09.1999 Christian Mayer Created
34 *****************************************************************************/
36 /****************************************************************************/
38 /****************************************************************************/
40 #include <simgear/compiler.h>
42 #ifdef FG_MATH_EXCEPTION_CLASH
48 #include <simgear/constants.h>
49 #include <simgear/debug/logstream.hxx>
50 #include <simgear/math/fg_geodesy.hxx>
51 #include <simgear/misc/fgpath.hxx>
53 #include <Aircraft/aircraft.hxx>
54 #include <Controls/controls.hxx>
55 #include <Main/options.hxx>
59 /****************************************************************************/
60 /********************************** CODE ************************************/
61 /****************************************************************************/
64 // Initialize the BalloonSim flight model, dt is the time increment for
65 // each subsequent iteration through the EOM
66 int FGBalloonSim::init( double dt ) {
69 FG_LOG( FG_FLIGHT, FG_INFO, "Starting initializing BalloonSim" );
71 FG_LOG( FG_FLIGHT, FG_INFO, " created a balloon" );
73 //set the dt of the model
74 current_balloon.set_dt(dt);
80 get_Altitude() * FEET_TO_METER);
81 current_balloon.setPosition( temp );
83 //set Euler angles (?)
88 current_balloon.setHPR( temp );
92 current_options.get_uBody(),
93 current_options.get_vBody(),
94 current_options.get_wBody() );
95 current_balloon.setVelocity( temp );
97 FG_LOG( FG_FLIGHT, FG_INFO, "Finished initializing BalloonSim" );
103 // Run an iteration of the EOM (equations of motion)
104 int FGBalloonSim::update( int multiloop ) {
105 double save_alt = 0.0;
107 // lets try to avoid really screwing up the BalloonSim model
108 if ( get_Altitude() < -9000 ) {
109 save_alt = get_Altitude();
113 // set control positions
114 current_balloon.set_burner_strength ( controls.get_throttle(0) );
115 //not more implemented yet
117 // Inform BalloonSim of the local terrain altitude
118 current_balloon.setGroundLevel ( get_Runway_altitude() * FEET_TO_METER);
120 // old -- FGInterface_2_JSBsim() not needed except for Init()
121 // translate FG to JSBsim structure
122 // FGInterface_2_JSBsim(f);
123 // printf("FG_Altitude = %.2f\n", FG_Altitude * 0.3048);
124 // printf("Altitude = %.2f\n", Altitude * 0.3048);
125 // printf("Radius to Vehicle = %.2f\n", Radius_to_vehicle * 0.3048);
127 /* FDMExec.GetState()->Setsim_time(State->Getsim_time()
128 + State->Getdt() * multiloop); */
130 for ( int i = 0; i < multiloop; i++ ) {
131 current_balloon.update();
134 // translate BalloonSim back to FG structure so that the
135 // autopilot (and the rest of the sim can use the updated
138 copy_from_BalloonSim();
140 /*sgVec3 temp, temp2;
141 current_balloon.getPosition( temp );
142 current_balloon.getVelocity( temp2 );
143 FG_LOG( FG_FLIGHT, FG_INFO, "T: " << current_balloon.getTemperature() <<
144 " alt: " << temp[2] <<
145 " gr_alt: " << get_Runway_altitude() <<
146 " burner: " << controls.get_elevator() <<
147 " v[2]: " << temp2[2]); */
149 // but lets restore our original bogus altitude when we are done
150 if ( save_alt < -9000.0 ) {
151 set_Altitude( save_alt );
158 // Convert from the FGInterface struct to the BalloonSim
159 int FGBalloonSim::copy_to_BalloonSim() {
164 // Convert from the BalloonSim to the FGInterface struct
165 int FGBalloonSim::copy_from_BalloonSim() {
170 current_balloon.getVelocity( temp );
171 set_Velocities_Local( temp[0], temp[1], temp[2] );
173 /* ***FIXME*** */ set_V_equiv_kts( sgLengthVec3 ( temp ) );
175 set_Omega_Body( 0.0, 0.0, 0.0 );
178 current_balloon.getPosition( temp );
179 double lat_geoc = temp[0];
180 double lon = temp[1];
181 double alt = temp[2] * METER_TO_FEET;
183 double lat_geod, tmp_alt, sl_radius1, sl_radius2, tmp_lat_geoc;
184 fgGeocToGeod( lat_geoc, EQUATORIAL_RADIUS_M + alt * FEET_TO_METER,
185 &lat_geod, &tmp_alt, &sl_radius1 );
186 fgGeodToGeoc( lat_geod, alt * FEET_TO_METER, &sl_radius2, &tmp_lat_geoc );
188 FG_LOG( FG_FLIGHT, FG_DEBUG, "lon = " << lon << " lat_geod = " << lat_geod
189 << " lat_geoc = " << lat_geoc
190 << " alt = " << alt << " tmp_alt = " << tmp_alt * METER_TO_FEET
191 << " sl_radius1 = " << sl_radius1 * METER_TO_FEET
192 << " sl_radius2 = " << sl_radius2 * METER_TO_FEET
193 << " Equator = " << EQUATORIAL_RADIUS_FT );
195 set_Geocentric_Position( lat_geoc, lon,
196 sl_radius2 * METER_TO_FEET + alt );
197 set_Geodetic_Position( lat_geod, lon, alt );
199 current_balloon.getHPR( temp );
200 set_Euler_Angles( temp[0], temp[1], temp[2] );
201 set_Euler_Rates(0,0,0);
203 set_Alpha( 0.0/*FDMExec.GetTranslation()->Getalpha()*/ );
204 set_Beta( 0.0/*FDMExec.GetTranslation()->Getbeta()*/ );
206 /* **FIXME*** */ set_Sea_level_radius( sl_radius2 * METER_TO_FEET );
207 /* **FIXME*** */ set_Earth_position_angle( 0.0 );
209 /* ***FIXME*** */ set_Runway_altitude( 0.0 );
211 set_sin_lat_geocentric( lat_geoc );
212 set_cos_lat_geocentric( lat_geoc );
213 set_sin_cos_longitude( lon );
214 set_sin_cos_latitude( lat_geod );