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 <Aircraft/aircraft.hxx>
54 #include <Main/globals.hxx>
55 #include <Main/fg_props.hxx>
59 /****************************************************************************/
60 /********************************** CODE ************************************/
61 /****************************************************************************/
64 FGBalloonSim::FGBalloonSim( double dt ) {
65 //set the dt of the model
66 current_balloon.set_dt(dt);
70 FGBalloonSim::~FGBalloonSim() {
74 // Initialize the BalloonSim flight model, dt is the time increment for
75 // each subsequent iteration through the EOM
76 void FGBalloonSim::init() {
78 //do init common to all the FDM's
81 //now do init specific to the Balloon
85 SG_LOG( SG_FLIGHT, SG_INFO, "Starting initializing BalloonSim" );
87 SG_LOG( SG_FLIGHT, SG_INFO, " created a balloon" );
93 get_Altitude() * SG_FEET_TO_METER);
94 current_balloon.setPosition( temp );
96 //set Euler angles (?)
101 current_balloon.setHPR( temp );
105 fgGetDouble("/sim/presets/uBody-fps"),
106 fgGetDouble("/sim/presets/vBody-fps"),
107 fgGetDouble("/sim/presets/wBody-fps") );
108 current_balloon.setVelocity( temp );
110 SG_LOG( SG_FLIGHT, SG_INFO, "Finished initializing BalloonSim" );
114 // Run an iteration of the EOM (equations of motion)
115 void FGBalloonSim::update( double dt ) {
116 double save_alt = 0.0;
121 int multiloop = _calc_multiloop(dt);
123 // lets try to avoid really screwing up the BalloonSim model
124 if ( get_Altitude() < -9000 ) {
125 save_alt = get_Altitude();
129 // set control positions
130 current_balloon.set_burner_strength ( globals->get_controls()->get_throttle(0) );
131 //not more implemented yet
133 // Inform BalloonSim of the local terrain altitude
134 current_balloon.setGroundLevel ( get_Runway_altitude() * SG_FEET_TO_METER);
136 // old -- FGInterface_2_JSBsim() not needed except for Init()
137 // translate FG to JSBsim structure
138 // FGInterface_2_JSBsim(f);
139 // printf("FG_Altitude = %.2f\n", FG_Altitude * 0.3048);
140 // printf("Altitude = %.2f\n", Altitude * 0.3048);
141 // printf("Radius to Vehicle = %.2f\n", Radius_to_vehicle * 0.3048);
143 /* FDMExec.GetState()->Setsim_time(State->Getsim_time()
144 + State->Getdt() * multiloop); */
146 for ( int i = 0; i < multiloop; i++ ) {
147 current_balloon.update();
150 // translate BalloonSim back to FG structure so that the
151 // autopilot (and the rest of the sim can use the updated
154 copy_from_BalloonSim();
156 /*sgVec3 temp, temp2;
157 current_balloon.getPosition( temp );
158 current_balloon.getVelocity( temp2 );
159 SG_LOG( SG_FLIGHT, SG_INFO, "T: " << current_balloon.getTemperature() <<
160 " alt: " << temp[2] <<
161 " gr_alt: " << get_Runway_altitude() <<
162 " burner: " << controls.get_elevator() <<
163 " v[2]: " << temp2[2]); */
165 // but lets restore our original bogus altitude when we are done
166 if ( save_alt < -9000.0 ) {
167 set_Altitude( save_alt );
172 // Convert from the FGInterface struct to the BalloonSim
173 bool FGBalloonSim::copy_to_BalloonSim() {
178 // Convert from the BalloonSim to the FGInterface struct
179 bool FGBalloonSim::copy_from_BalloonSim() {
184 current_balloon.getVelocity( temp );
185 _set_Velocities_Local( temp[0], temp[1], temp[2] );
187 /* ***FIXME*** */ _set_V_equiv_kts( sgLengthVec3 ( temp ) );
189 _set_Omega_Body( 0.0, 0.0, 0.0 );
192 current_balloon.getPosition( temp );
193 //temp[0]: geocentric latitude
195 //temp[2]: altitude (meters)
197 _updateGeocentricPosition( temp[0], temp[1], temp[2] * SG_METER_TO_FEET );
199 current_balloon.getHPR( temp );
200 set_Euler_Angles( temp[0], temp[1], temp[2] );