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
21 along with this program; if not, write to the Free Software
22 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 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 /****************************************************************************/
44 #include <simgear/compiler.h>
48 #include <simgear/constants.h>
49 #include <simgear/debug/logstream.hxx>
50 #include <simgear/math/sg_geodesy.hxx>
51 #include <simgear/misc/sg_path.hxx>
53 #include <Main/globals.hxx>
54 #include <Main/fg_props.hxx>
55 #include <Aircraft/controls.hxx>
60 /****************************************************************************/
61 /********************************** CODE ************************************/
62 /****************************************************************************/
65 FGBalloonSim::FGBalloonSim( double dt ) {
66 //set the dt of the model
67 current_balloon.set_dt(dt);
71 FGBalloonSim::~FGBalloonSim() {
75 // Initialize the BalloonSim flight model, dt is the time increment for
76 // each subsequent iteration through the EOM
77 void FGBalloonSim::init() {
79 //do init common to all the FDM's
82 //now do init specific to the Balloon
84 SG_LOG( SG_FLIGHT, SG_INFO, "Starting initializing BalloonSim" );
86 SG_LOG( SG_FLIGHT, SG_INFO, " created a balloon" );
89 SGVec3f temp(get_Latitude(),
91 get_Altitude() * SG_FEET_TO_METER);
92 current_balloon.setPosition( temp );
94 //set Euler angles (?)
95 temp = SGVec3f(get_Phi(),
98 current_balloon.setHPR( temp );
101 temp = SGVec3f(fgGetDouble("/sim/presets/uBody-fps"),
102 fgGetDouble("/sim/presets/vBody-fps"),
103 fgGetDouble("/sim/presets/wBody-fps") );
104 current_balloon.setVelocity( temp );
106 SG_LOG( SG_FLIGHT, SG_INFO, "Finished initializing BalloonSim" );
110 // Run an iteration of the EOM (equations of motion)
111 void FGBalloonSim::update( double dt ) {
112 double save_alt = 0.0;
117 int multiloop = _calc_multiloop(dt);
119 // lets try to avoid really screwing up the BalloonSim model
120 if ( get_Altitude() < -9000 ) {
121 save_alt = get_Altitude();
125 // set control positions
126 current_balloon.set_burner_strength ( globals->get_controls()->get_throttle(0) );
127 //not more implemented yet
129 // Inform BalloonSim of the local terrain altitude
130 current_balloon.setGroundLevel ( get_Runway_altitude() * SG_FEET_TO_METER);
132 // old -- FGInterface_2_JSBsim() not needed except for Init()
133 // translate FG to JSBsim structure
134 // FGInterface_2_JSBsim(f);
135 // printf("FG_Altitude = %.2f\n", FG_Altitude * 0.3048);
136 // printf("Altitude = %.2f\n", Altitude * 0.3048);
137 // printf("Radius to Vehicle = %.2f\n", Radius_to_vehicle * 0.3048);
139 /* FDMExec.GetState()->Setsim_time(State->Getsim_time()
140 + State->Getdt() * multiloop); */
142 for ( int i = 0; i < multiloop; i++ ) {
143 current_balloon.update();
146 // translate BalloonSim back to FG structure so that the
147 // autopilot (and the rest of the sim can use the updated
150 copy_from_BalloonSim();
152 /*sgVec3 temp, temp2;
153 current_balloon.getPosition( temp );
154 current_balloon.getVelocity( temp2 );
155 SG_LOG( SG_FLIGHT, SG_INFO, "T: " << current_balloon.getTemperature() <<
156 " alt: " << temp[2] <<
157 " gr_alt: " << get_Runway_altitude() <<
158 " burner: " << controls.get_elevator() <<
159 " v[2]: " << temp2[2]); */
161 // but lets restore our original bogus altitude when we are done
162 if ( save_alt < -9000.0 ) {
163 set_Altitude( save_alt );
168 // Convert from the FGInterface struct to the BalloonSim
169 bool FGBalloonSim::copy_to_BalloonSim() {
174 // Convert from the BalloonSim to the FGInterface struct
175 bool FGBalloonSim::copy_from_BalloonSim() {
180 current_balloon.getVelocity( temp );
181 _set_Velocities_Local( temp[0], temp[1], temp[2] );
183 /* ***FIXME*** */ _set_V_equiv_kts( length( temp ) );
185 _set_Omega_Body( 0.0, 0.0, 0.0 );
188 current_balloon.getPosition( temp );
189 //temp[0]: geocentric latitude
191 //temp[2]: altitude (meters)
193 _updateGeocentricPosition( temp[0], temp[1], temp[2] * SG_METER_TO_FEET );
195 current_balloon.getHPR( temp );
196 set_Euler_Angles( temp[0], temp[1], temp[2] );