BalloonSim.h

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/*****************************************************************************
 
 Header:       BalloonSim.h     
 Author:       Christian Mayer
 Date started: 01.09.99
 
 -------- Copyright (C) 1999 Christian Mayer (fgfs@christianmayer.de) --------
 
 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
 Further information about the GNU General Public License can also be found on
 the world wide web at http://www.gnu.org.
 
FUNCTIONAL DESCRIPTION
------------------------------------------------------------------------------
Header for the hot air balloon simulator
 
HISTORY
------------------------------------------------------------------------------
01.09.1999 Christian Mayer      Created
03.10.1999 Christian Mayer      cleaned  the code  by moveing  WeatherDatabase 
                                calls inside the update()
*****************************************************************************/
 
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/* SENTRY                                                                   */
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#ifndef BalloonSim_H
#define BalloonSim_H
 
#include <cfloat>
 
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/* INCLUDES                                                                 */
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#include <simgear/math/SGMath.hxx>
                
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/* DEFINES                                                                  */
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/* CLASS DECLARATION                                                        */
/****************************************************************************/
class balloon
{
private:
    float dt;                           //in s
 
    SGVec3f gravity_vector;             //in m/s*s
    SGVec3f hpr;                                //the balloon isn't allways exactly vertical (e.g. during gusts); normalized
    SGVec3f velocity;                   //current velocity; it gets iterated at each 'update'
    SGVec3f position;                   //current position in lat/lon/alt
 
    float balloon_envelope_area;        //area of the envelope
    float balloon_envelope_volume;      //volume of the envelope
 
    float wind_facing_area_of_balloon;
    float wind_facing_area_of_basket;
 
    float cw_envelope;                  //wind resistance of the envelope
    float cw_basket;                    //wind resistance of the bakset
 
    //all weights in kg
    float weight_of_total_fuel;
    float weight_of_envelope;
    float weight_of_basket;             //weight of all the unmovable stuff such as the basket, the burner and the empty tanks
    float weight_of_cargo;              //passengers and anything left (e.g. sand bags that are thrown away to give additional lift)
 
    float fuel_left;                    //as a percentage
    float max_flow_of_fuel_per_second;  //in percent per second 
    float current_burner_strength;
 
    float lambda;                       //waermeuebergangskoeffizient (heat transmission coefficent?!?) for the envelope
    float l_of_the_envelope;            //the thickness of the envelope (in m)
 
    float T;                            //tempereature inside the balloon
 
    float ground_level;
 
public:
    balloon();                           //constructor for initializing the balloon 
 
    void update();                        //dt = time in seconds since last call
    void set_burner_strength(const float bs);
 
    void getVelocity(SGVec3f& v) const;
    void setVelocity(const SGVec3f& v);
 
    void getPosition(SGVec3f& v) const;
    void setPosition(const SGVec3f& v);
 
    void getHPR(SGVec3f& angles) const;   //the balloon isn't allways exactly vertical
    void setHPR(const SGVec3f& angles);   //the balloon isn't allways exactly vertical
 
    void setGroundLevel(const float altitude);
 
    float getTemperature(void) const;
    float getFuelLeft(void) const;
 
    void set_dt(const float new_dt) { dt = new_dt; }
};
 
/****************************************************************************/
#endif /*BalloonSim_H*/